@article {pmid36986852, year = {2023}, author = {Fathil, MAM and Katas, H}, title = {Antibacterial, Anti-Biofilm and Pro-Migratory Effects of Double Layered Hydrogels Packaged with Lactoferrin-DsiRNA-Silver Nanoparticles for Chronic Wound Therapy.}, journal = {Pharmaceutics}, volume = {15}, number = {3}, pages = {}, doi = {10.3390/pharmaceutics15030991}, pmid = {36986852}, issn = {1999-4923}, abstract = {Antimicrobial resistance and biofilm formation in diabetic foot infections worsened during the COVID-19 pandemic, resulting in more severe infections and increased amputations. Therefore, this study aimed to develop a dressing that could effectively aid in the wound healing process and prevent bacterial infections by exerting both antibacterial and anti-biofilm effects. Silver nanoparticles (AgNPs) and lactoferrin (LTF) have been investigated as alternative antimicrobial and anti-biofilm agents, respectively, while dicer-substrate short interfering RNA (DsiRNA) has also been studied for its wound healing effect in diabetic wounds. In this study, AgNPs were complexed with LTF and DsiRNA via simple complexation before packaging in gelatin hydrogels. The formed hydrogels exhibited 1668% maximum swellability, with a 46.67 ± 10.33 µm average pore size. The hydrogels demonstrated positive antibacterial and anti-biofilm effects toward the selected Gram-positive and Gram-negative bacteria. The hydrogel containing AgLTF at 125 µg/mL was also non-cytotoxic on HaCaT cells for up to 72 h of incubation. The hydrogels containing DsiRNA and LTF demonstrated superior pro-migratory effects compared to the control group. In conclusion, the AgLTF-DsiRNA-loaded hydrogel possessed antibacterial, anti-biofilm, and pro-migratory activities. These findings provide a further understanding and knowledge on forming multipronged AgNPs consisting of DsiRNA and LTF for chronic wound therapy.}, }
@article {pmid36985403, year = {2023}, author = {Liu, X and Yao, H and Zhao, X and Ge, C}, title = {Biofilm Formation and Control of Foodborne Pathogenic Bacteria.}, journal = {Molecules (Basel, Switzerland)}, volume = {28}, number = {6}, pages = {}, doi = {10.3390/molecules28062432}, pmid = {36985403}, issn = {1420-3049}, abstract = {Biofilms are microbial aggregation membranes that are formed when microorganisms attach to the surfaces of living or nonliving things. Importantly, biofilm properties provide microorganisms with protection against environmental pressures and enhance their resistance to antimicrobial agents, contributing to microbial persistence and toxicity. Thus, bacterial biofilm formation is part of the bacterial survival mechanism. However, if foodborne pathogens form biofilms, the risk of foodborne disease infections can be greatly exacerbated, which can cause major public health risks and lead to adverse economic consequences. Therefore, research on biofilms and their removal strategies are very important in the food industry. Food waste due to spoilage within the food industry remains a global challenge to environmental sustainability and the security of food supplies. This review describes bacterial biofilm formation, elaborates on the problem associated with biofilms in the food industry, enumerates several kinds of common foodborne pathogens in biofilms, summarizes the current strategies used to eliminate or control harmful bacterial biofilm formation, introduces the current and emerging control strategies, and emphasizes future development prospects with respect to bacterial biofilms.}, }
@article {pmid36985334, year = {2023}, author = {Richter, AM and Konrat, K and Osland, AM and Brook, E and Oastler, C and Vestby, LK and Gosling, RJ and Nesse, LL and Arvand, M}, title = {Evaluation of Biofilm Cultivation Models for Efficacy Testing of Disinfectants against Salmonella Typhimurium Biofilms.}, journal = {Microorganisms}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/microorganisms11030761}, pmid = {36985334}, issn = {2076-2607}, abstract = {Within the European Union, Salmonella is frequently reported in food and feed products. A major route of transmission is upon contact with contaminated surfaces. In nature, bacteria such as Salmonella are often encountered in biofilms, where they are protected against antibiotics and disinfectants. Therefore, the removal and inactivation of biofilms is essential to ensure hygienic conditions. Currently, recommendations for disinfectant usage are based on results of efficacy testing against planktonic bacteria. There are no biofilm-specific standards for the efficacy testing of disinfectants against Salmonella. Here, we assessed three models for disinfectant efficacy testing on Salmonella Typhimurium biofilms. Achievable bacterial counts per biofilm, repeatability, and intra-laboratory reproducibility were analyzed. Biofilms of two Salmonella strains were grown on different surfaces and treated with glutaraldehyde or peracetic acid. Disinfectant efficacy was compared with results for planktonic Salmonella. All methods resulted in highly repeatable cell numbers per biofilm, with one assay showing variations of less than 1 log10 CFU in all experiments for both strains tested. Disinfectant concentrations required to inactivate biofilms were higher compared to planktonic cells. Differences were found between the biofilm methods regarding maximal achievable cell numbers, repeatability, and intra-laboratory reproducibility of results, which may be used to identify the most appropriate method in relation to application context. Developing a standardized protocol for testing disinfectant efficacy on biofilms will help identify conditions that are effective against biofilms.}, }
@article {pmid36985206, year = {2023}, author = {da Silva, AA and Galego, L and Arraiano, CM}, title = {New Perspectives on BolA: A Still Mysterious Protein Connecting Morphogenesis, Biofilm Production, Virulence, Iron Metabolism, and Stress Survival.}, journal = {Microorganisms}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/microorganisms11030632}, pmid = {36985206}, issn = {2076-2607}, abstract = {The BolA-like protein family is widespread among prokaryotes and eukaryotes. BolA was originally described in E. coli as a gene induced in the stationary phase and in stress conditions. The BolA overexpression makes cells spherical. It was characterized as a transcription factor modulating cellular processes such as cell permeability, biofilm production, motility, and flagella assembly. BolA is important in the switch between motile and sedentary lifestyles having connections with the signaling molecule c-di-GMP. BolA was considered a virulence factor in pathogens such as Salmonella Typhimurium and Klebsiella pneumoniae and it promotes bacterial survival when facing stresses due to host defenses. In E. coli, the BolA homologue IbaG is associated with resistance to acidic stress, and in Vibrio cholerae, IbaG is important for animal cell colonization. Recently, it was demonstrated that BolA is phosphorylated and this modification is important for the stability/turnover of BolA and its activity as a transcription factor. The results indicate that there is a physical interaction between BolA-like proteins and the CGFS-type Grx proteins during the biogenesis of Fe-S clusters, iron trafficking and storage. We also review recent progress regarding the cellular and molecular mechanisms by which BolA/Grx protein complexes are involved in the regulation of iron homeostasis in eukaryotes and prokaryotes.}, }
@article {pmid36985196, year = {2023}, author = {Marra, D and Perna, I and Pota, G and Vitiello, G and Pezzella, A and Toscano, G and Luciani, G and Caserta, S}, title = {Nanoparticle Coatings on Glass Surfaces to Prevent Pseudomonas fluorescens AR 11 Biofilm Formation.}, journal = {Microorganisms}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/microorganisms11030621}, pmid = {36985196}, issn = {2076-2607}, abstract = {Microbial colonization of surfaces is a sanitary and industrial issue for many applications, leading to product contamination and human infections. When microorganisms closely interact with a surface, they start to produce an exo-polysaccaridic matrix to adhere to and protect themselves from adverse environmental conditions. This type of structure is called a biofilm. The aim of our work is to investigate novel technologies able to prevent biofilm formation by surface coatings. We coated glass surfaces with melanin-ZnO2, melanin-TiO2, and TiO2 hybrid nanoparticles. The functionalization was performed using cold plasma to activate glass-substrate-coated surfaces, that were characterized by performing water and soybean oil wetting tests. A quantitative characterization of the antibiofilm properties was done using Pseudomonas fluorescens AR 11 as a model organism. Biofilm morphologies were observed using confocal laser scanning microscopy and image analysis techniques were used to obtain quantitative morphological parameters. The results highlight the efficacy of the proposed surface coating to prevent biofilm formation. Melanin-TiO2 proved to be the most efficient among the particles investigated. Our results can be a valuable support for future implementation of the technique proposed here in an extended range of applications that may include further testing on other strains and other support materials.}, }
@article {pmid36985130, year = {2023}, author = {Rühl-Teichner, J and Jacobmeyer, L and Leidner, U and Semmler, T and Ewers, C}, title = {Genomic Diversity, Antimicrobial Susceptibility, and Biofilm Formation of Clinical Acinetobacter baumannii Isolates from Horses.}, journal = {Microorganisms}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/microorganisms11030556}, pmid = {36985130}, issn = {2076-2607}, abstract = {Acinetobacter (A.) baumannii is an opportunistic pathogen that causes severe infections in humans and animals, including horses. The occurrence of dominant international clones (ICs), frequent multidrug resistance, and the capability to form biofilms are considered major factors in the successful spread of A. baumannii in human and veterinary clinical environments. Since little is known about A. baumannii isolates from horses, we studied 78 equine A. baumannii isolates obtained from clinical samples between 2008 and 2020 for their antimicrobial resistance (AMR), clonal distribution, biofilm-associated genes (BAGs), and biofilm-forming capability. Based on whole-genome sequence analyses, ICs, multilocus (ML) and core-genome ML sequence types (STs), and AMR genes were determined. Antimicrobial susceptibility testing was performed by microbroth dilution. A crystal violet assay was used for biofilm quantification. Almost 37.2% of the isolates were assigned to IC1 (10.3%), IC2 (20.5%), and IC3 (6.4%). Overall, the isolates revealed high genomic diversity. We identified 51 different STs, including 22 novel STs (ST1723-ST1744), and 34 variants of the intrinsic oxacillinase (OXA), including 8 novel variants (OXA-970 to OXA-977). All isolates were resistant to ampicillin, amoxicillin/clavulanic acid, cephalexin, cefpodoxime, and nitrofurantoin. IC1-IC3 isolates were also resistant to gentamicin, enrofloxacin, marbofloxacin, tetracycline, and trimethoprim/sulfamethoxazole. All isolates were susceptible to imipenem. Thirty-one multidrug-resistant (MDR) isolates mainly accumulated in the IC1-IC3 groups. In general, these isolates showed less biofilm formation (IC1 = 25.0%, IC2 = 18.4%, IC3 = 15.0%) than the group of non-IC1-IC3 isolates (58.4%). Isolates belonging to the same ICs/STs revealed identical BAG patterns. BAG blp1 was absent in all isolates, whereas bfmR and pgaA were present in all isolates. At the level of the IC groups, the AMR status was negatively correlated with the isolates' ability to form a biofilm. A considerable portion of equine A. baumannii isolates revealed ICs/STs that are globally present in humans. Both an MDR phenotype and the capability to form biofilms might lead to therapeutic failures in equine medicine, particularly due to the limited availability of licensed drugs.}, }
@article {pmid36985119, year = {2023}, author = {Ioannidis, A and Chatzipanagiotou, S and Vassilaki, N and Giannakopoulos, P and Hatzaki, D and Magana, M and Sachlas, A and Mpekoulis, G and Radiotis, A and Tsakanikos, M and Tzanakaki, G and Lebessi, E and Tsolia, MN}, title = {Biofilm-Forming Bacteria Implicated in Complex Otitis Media in Children in the Post-Heptavalent Pneumococcal Conjugate Vaccine (PCV7) Era.}, journal = {Microorganisms}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/microorganisms11030545}, pmid = {36985119}, issn = {2076-2607}, abstract = {Background: Chronic media with effusion (COME) and recurrent acute otitis media (RAOM) are closely related clinical entities that affect childhood. The aims of the study were to investigate the microbiological profile of otitis-prone children in the post-PCV7 era and, to examine the biofilm-forming ability in association with clinical history and outcome during a two-year post-operative follow-up. Methods: In this prospective study, pathogens from patients with COME and RAOM were isolated and studied in vitro for their biofilm-forming ability. The minimum inhibitory concentrations (MIC) of both the planktonic and the sessile forms were compared. The outcome of the therapeutic method used in each case and patient history were correlated with the pathogens and their ability to form biofilms. Results: Haemophilus influenzae was the leading pathogen (35% in COME and 40% in RAOM), and Streptococcus pneumoniae ranked second (12% in COME and 24% in RAOM). Polymicrobial infections were identified in 5% of COME and 19% of RAOM cases. Of the isolated otopathogens, 94% were positive for biofilm formation. Conclusions: This is the first Greek research studying biofilm formation in complex otitis media-prone children population in the post-PCV7 era. High rates of polymicrobial infections, along with treatment failure in biofilms, may explain the lack of antimicrobial efficacy in otitis-prone children.}, }
@article {pmid36984711, year = {2023}, author = {Li, S and Duan, L and Zhao, Y and Gao, F and Hermanowicz, SW}, title = {Analysis of Microbial Communities in Membrane Biofilm Reactors Using a High-Density Microarray.}, journal = {Membranes}, volume = {13}, number = {3}, pages = {}, doi = {10.3390/membranes13030324}, pmid = {36984711}, issn = {2077-0375}, abstract = {Membrane biofilm reactors (MBfRs) have attracted more and more attention in the field of wastewater treatment due to their advantages of high mass transfer efficiency and low-carbon emissions. There are many factors affecting their nitrogen removal abilities, such as operation time, electron donor types, and operation modes. The operation time is directly related to the growth status of microorganisms, so it is very important to understand the effect of different operation times on microbial composition and community succession. In this study, two parallel H2-based MBfRs were operated, and differences in microbial composition, community succession, and NO3[-]-N removal efficiency were investigated on the 30th day and the 60th day of operation. The nitrogen removal efficiency of MBfRs with an operation time of 60 days was higher than that of MBfRs with an operation time of 30 days. Proteobacteria was the dominant phylum in both MBfRs; however, the composition of the microbial community was quite different. At the class level, the community composition of Proteobacteria was similar between the two MBfRs. Alphaproteobacteria was the dominant class in MBfR, and Betaproteobacteria and Gammaproteobacteria were also in high proportion. Combined with the analysis of microbial relative abundance and concentration, the similarity of microbial distribution in the MBfRs was very low on day 30 and day 60, and the phylogenetic relationships of the top 50 dominant universal bacteria and Proteobacteria were different. Although the microbial concentration decreased with the extension of the operation time, the microbial abundance and diversity of specific functional microorganisms increased further. Therefore, the operation time had a significant effect on microbial composition and community succession.}, }
@article {pmid36983858, year = {2023}, author = {Alenazy, R}, title = {Antimicrobial Activities and Biofilm Inhibition Properties of Trigonella foenumgraecum Methanol Extracts against Multidrug-Resistant Staphylococcus aureus and Escherichia coli.}, journal = {Life (Basel, Switzerland)}, volume = {13}, number = {3}, pages = {}, doi = {10.3390/life13030703}, pmid = {36983858}, issn = {2075-1729}, abstract = {Multidrug-resistant bacteria are becoming the leading cause of death globally due to their resistance to many currently used antibiotics. Bacteria naturally have intrinsic resistance or acquired resistance to certain commonly used antibiotics. Therefore, searching for novel compounds has become necessary. Trigonella foenumgraecum extract was evaluated for antimicrobial and antibiofilm activities against multidrug-resistant bacteria Staphylococcus aureus and Escherichia coli. The minimum inhibitory concentration and minimum bactericidal concentration of the extract were also determined. Moreover, gas chromatography-mass spectrometry (GC-MS) analysis was used to identify the phytochemical components present in the extract. GC-MS analysis revealed that T. foenumgraecum extract contains major compounds such as Phenol, 2-methoxy-3-(2-propenyl)-, n-Hexadecanoic acid, and 9,12,15-Octadecatrienoic acid. Both bacterial strains showed resistance to some of the antibiotics tested. T. foenumgraecum showed inhibitory activity against the tested bacterial strains with a MIC of 500 µg/mL and MBC of 1000 µg/mL. The methanol extract decreased the biofilm activity of both E. coli and S. aureus below the sub-minimum inhibitory concentration. The extract showed antibacterial and antibiofilm activity against the tested bacterial pathogens.}, }
@article {pmid36983523, year = {2023}, author = {Maione, A and Imparato, M and Buonanno, A and Carraturo, F and Schettino, A and Schettino, MT and Galdiero, M and de Alteriis, E and Guida, M and Galdiero, E}, title = {Anti-Biofilm Activity of Phenyllactic Acid against Clinical Isolates of Fluconazole-Resistant Candida albicans.}, journal = {Journal of fungi (Basel, Switzerland)}, volume = {9}, number = {3}, pages = {}, doi = {10.3390/jof9030355}, pmid = {36983523}, issn = {2309-608X}, abstract = {Commonly found colonizing the human microbiota, Candida albicans is a microorganism known for its ability to cause infections, mainly in the vulvovaginal region, and is responsible for 85% to 90% of vulvovaginal candidiasis (VVC) cases. The development of drug resistance in C. albicans isolates after long-term therapy with fluconazole is an important complication to solve and new therapeutic strategies are required to target this organism and its pathogenicity. In the present study, phenyllactic acid (PLA) an important broad-spectrum antimicrobial compound was investigated for its antifungal and antivirulence activities against clinical isolates of C. albicans. Previously characterized strains of C. albicans isolates from women with VVC and C. albicans ATCC90028 were used to evaluate the antimicrobial and time dependent killing assay activity of PLA showing a MIC 7.5 mg mL[-1] and a complete reduction of viable Candida cells detected by killing kinetics after 4 h of treatment with PLA. Additionally, PLA significantly reduced the biomass and the metabolic activity of C. albicans biofilms and impaired biofilm formation also with changes in ERG11, ALS3, and HWP1 genes expression as detected by qPCR. PLA eradicated pre-formed biofilms as showed also with confocal laser scanning microscopy (CLSM) observations. Furthermore, the compound prolonged the survival rate of Galleria mellonella infected by C. albicans isolates. These results indicate that PLA is a promising candidate as novel and safe antifungal agents for the treatment of vulvovaginal candidiasis.}, }
@article {pmid36982399, year = {2023}, author = {Li, Y and Chen, X and Xu, X and Yu, C and Liu, Y and Jiang, N and Li, J and Luo, L}, title = {Deletion of pbpC Enhances Bacterial Pathogenicity on Tomato by Affecting Biofilm Formation, Exopolysaccharides Production, and Exoenzyme Activities in Clavibacter michiganensis.}, journal = {International journal of molecular sciences}, volume = {24}, number = {6}, pages = {}, doi = {10.3390/ijms24065324}, pmid = {36982399}, issn = {1422-0067}, abstract = {Penicillin-binding proteins (PBPs) are considered essential for bacterial peptidoglycan biosynthesis and cell wall assembly. Clavibacter michiganensis is a representative Gram-positive bacterial species that causes bacterial canker in tomato. pbpC plays a significant role in maintaining cell morphological characteristics and stress responses in C. michiganensis. The current study demonstrated that the deletion of pbpC commonly enhances bacterial pathogenicity in C. michiganensis and revealed the mechanisms through which this occurs. The expression of interrelated virulence genes, including celA, xysA, xysB, and pelA, were significantly upregulated in △pbpC mutants. Compared with those in wild-type strains, exoenzyme activities, the formation of biofilm, and the production of exopolysaccharides (EPS) were significantly increased in △pbpC mutants. It is noteworthy that EPS were responsible for the enhancement in bacterial pathogenicity, with the degree of necrotic tomato stem cankers intensifying with the injection of a gradient of EPS from C. michiganensis. These findings highlight new insights into the role of pbpC affecting bacterial pathogenicity, with an emphasis on EPS, advancing the current understanding of phytopathogenic infection strategies for Gram-positive bacteria.}, }
@article {pmid36982293, year = {2023}, author = {François, P and Schrenzel, J and Götz, F}, title = {Biology and Regulation of Staphylococcal Biofilm.}, journal = {International journal of molecular sciences}, volume = {24}, number = {6}, pages = {}, doi = {10.3390/ijms24065218}, pmid = {36982293}, issn = {1422-0067}, abstract = {Despite continuing progress in medical and surgical procedures, staphylococci remain the major Gram-positive bacterial pathogens that cause a wide spectrum of diseases, especially in patients requiring the utilization of indwelling catheters and prosthetic devices implanted temporarily or for prolonged periods of time. Within the genus, if Staphylococcus aureus and S. epidermidis are prevalent species responsible for infections, several coagulase-negative species which are normal components of our microflora also constitute opportunistic pathogens that are able to infect patients. In such a clinical context, staphylococci producing biofilms show an increased resistance to antimicrobials and host immune defenses. Although the biochemical composition of the biofilm matrix has been extensively studied, the regulation of biofilm formation and the factors contributing to its stability and release are currently still being discovered. This review presents and discusses the composition and some regulation elements of biofilm development and describes its clinical importance. Finally, we summarize the numerous and various recent studies that address attempts to destroy an already-formed biofilm within the clinical context as a potential therapeutic strategy to avoid the removal of infected implant material, a critical event for patient convenience and health care costs.}, }
@article {pmid36981945, year = {2023}, author = {Lopez-Gigosos, RM and Mariscal-Lopez, E and Gutierrez-Bedmar, M and Mariscal, A}, title = {Effect of Long-Term Use of Alcohol-Containing Handwashing Gels on the Biofilm-Forming Capacity of Staphylococcus epidermidis.}, journal = {International journal of environmental research and public health}, volume = {20}, number = {6}, pages = {}, doi = {10.3390/ijerph20065037}, pmid = {36981945}, issn = {1660-4601}, abstract = {The spread of coronavirus disease 2019 (COVID-19) has promoted the use of hand sanitizers among the general population as recommended by health authorities. Alcohols, which are used in many hand sanitizers, have been shown to promotes the formation of biofilms by certain bacteria and to increase bacterial resistance to disinfection. We investigated the effect of continued use of alcohol-based gel hand sanitizer on biofilm formation by the Staphylococcus epidermidis resident strain isolated from the hands of health science students. Hand microbes were counted before and after handwashing, and the ability to produce biofilms was investigated. We found that 179 (84.8%) strains of S. epidermidis isolated from hands had the ability to form biofilm (biofilm-positive strains) in an alcohol-free culture medium. Furthermore, the presence of alcohol in the culture medium induced biofilm formation in 13 (40.6%) of the biofilm-negative strains and increased biofilm production in 111 (76.6%) strains, which were classified as low-grade biofilm-producing. Based on our findings, there is no clear evidence that the continued use of alcohol-based gels results in the selection of strains with the capacity to form biofilms. However, other disinfectant formulations that are more commonly used in clinical settings, such as alcohol-based hand-rub solutions, should be tested for their long-term effects.}, }
@article {pmid36979940, year = {2023}, author = {Shahab, M and Danial, M and Khan, T and Liang, C and Duan, X and Wang, D and Gao, H and Zheng, G}, title = {In Silico Identification of Lead Compounds for Pseudomonas Aeruginosa PqsA Enzyme: Computational Study to Block Biofilm Formation.}, journal = {Biomedicines}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/biomedicines11030961}, pmid = {36979940}, issn = {2227-9059}, abstract = {Pseudomonas aeruginosa is an opportunistic Gram-negative bacterium implicated in acute and chronic nosocomial infections and a leading cause of patient mortality. Pseudomonas aeruginosa infections are frequently associated with the development of biofilms, which give the bacteria additional drug resistance and increase their virulence. The goal of this study was to find strong compounds that block the Anthranilate-CoA ligase enzyme made by the pqsA gene. This would stop the P. aeruginosa quorum signaling system. This enzyme plays a crucial role in the pathogenicity of P. aeruginosa by producing autoinducers for cell-to-cell communication that lead to the production of biofilms. Pharmacophore-based virtual screening was carried out utilizing a library of commercially accessible enzyme inhibitors. The most promising hits obtained during virtual screening were put through molecular docking with the help of MOE. The virtual screening yielded 7/160 and 10/249 hits (ZINC and Chembridge). Finally, 2/7 ZINC hits and 2/10 ChemBridge hits were selected as potent lead compounds employing diverse scaffolds due to their high pqsA enzyme binding affinity. The results of the pharmacophore-based virtual screening were subsequently verified using a molecular dynamic simulation-based study (MDS). Using MDS and post-MDS, the stability of the complexes was evaluated. The most promising lead compounds exhibited a high binding affinity towards protein-binding pocket and interacted with the catalytic dyad. At least one of the scaffolds selected will possibly prove useful for future research. However, further scientific confirmation in the form of preclinical and clinical research is required before implementation.}, }
@article {pmid36979838, year = {2023}, author = {Zanetta, P and Squarzanti, DF and di Coste, A and Amoruso, A and Pane, M and Azzimonti, B}, title = {Growth Conditions Influence Lactobacillus Cell-Free Supernatant Impact on Viability, Biofilm Formation, and Co-Aggregation of the Oral Periodontopathogens Fusobacterium nucleatum and Porphyromonas gingivalis.}, journal = {Biomedicines}, volume = {11}, number = {3}, pages = {}, doi = {10.3390/biomedicines11030859}, pmid = {36979838}, issn = {2227-9059}, abstract = {Fusobacterium nucleatum and Porphyromonas gingivalis human periodontopathogens play a leading part in oral squamous cell carcinoma through cell proliferation, invasion, and persistent inflammation promotion and maintenance. To explore how the activity of Lactobacillus-derived cell-free supernatants (CFSs) can be influenced by growth medium components, CFSs were produced both in the standard MRS and the novel animal-derivative-free "Terreno Industriale Lattobacilli" (TIL) media, and in vitro screened for the containment of F. nucleatum and P. gingivalis both single and co-cultured and also for the interference on their co-aggregation. The viability assay demonstrated that the Limosilactobacillus reuteri LRE11 and Ligilactobacillus salivarius LS03 MRS-produced CFSs were significantly more effective against single and co-cultured pathogens. All the other CFSs significantly improved their efficacy when produced in TIL. Both MRS- and TIL-produced CFSs significantly inhibited the single and co-cultured pathogen biofilm formation. Only Levilactobacillus brevis LBR01 CFS in MRS specifically reduced F. nucleatum and P. gingivalis co-aggregation, while viable LBR01, LS03, and LRE11 in MRS significantly co-aggregated with the pathogens, but only LS03 cultivated in TIL improved this effect. This work paves the way to better consider environmental growth conditions when screening for probiotic and postbiotic efficacy as crucial to pathogen aggregation, adhesion to the host's niches, and exclusion.}, }
@article {pmid36979113, year = {2023}, author = {El-Hossary, D and Mahdy, A and Elariny, EYT and Askora, A and Merwad, AMA and Saber, T and Dahshan, H and Hakami, NY and Ibrahim, RA}, title = {Antibiotic Resistance, Virulence Gene Detection, and Biofilm Formation in Aeromonas spp. Isolated from Fish and Humans in Egypt.}, journal = {Biology}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/biology12030421}, pmid = {36979113}, issn = {2079-7737}, abstract = {The genus Aeromonas is widely distributed in aquatic environments and is recognized as a potential human pathogen. Some Aeromonas species are able to cause a wide spectrum of diseases, mainly gastroenteritis, skin and soft-tissue infections, bacteremia, and sepsis. The aim of the current study was to determine the prevalence of Aeromonas spp. in raw fish markets and humans in Zagazig, Egypt; identify the factors that contribute to virulence; determine the isolates' profile of antibiotic resistance; and to elucidate the ability of Aeromonas spp. to form biofilms. The examined samples included fish tissues and organs from tilapia (Oreochromis niloticus, n = 160) and mugil (Mugil cephalus, n = 105), and human skin swabs (n = 51) and fecal samples (n = 27). Based on biochemical and PCR assays, 11 isolates (3.2%) were confirmed as Aeromonas spp. and four isolates (1.2%) were confirmed as A. hydrophila. The virulence genes including haemolysin (hyl A) and aerolysin (aer) were detected using PCR in A. hydrophila in percentages of 25% and 50%, respectively. The antimicrobial resistance of Aeromonas spp. was assessed against 14 antibiotics comprising six classes. The resistance to cefixime (81.8%) and tobramycin (45.4%) was observed. The multiple antibiotic resistance (MAR) index ranged between 0.142-0.642 with 64.2% of the isolates having MAR values equal to 0.642. Biofilm formation capacity was assessed using a microtiter plate assay, and two isolates (18.1%) were classified as biofilm producers. This study establishes a baseline for monitoring and controlling the multidrug-resistant Aeromonas spp. and especially A. hydrophila in marine foods consumed in our country to protect humans and animals.}, }
@article {pmid36978493, year = {2023}, author = {Akinduti, PA and George, OW and Ohore, HU and Ariyo, OE and Popoola, ST and Adeleye, AI and Akinwande, KS and Popoola, JO and Rotimi, SO and Olufemi, FO and Omonhinmin, CA and Olasehinde, GI}, title = {Evaluation of Efflux-Mediated Resistance and Biofilm formation in Virulent Pseudomonas aeruginosa Associated with Healthcare Infections.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/antibiotics12030626}, pmid = {36978493}, issn = {2079-6382}, abstract = {Pseudomonas aeruginosa is a significant pathogen identified with healthcare-associated infections. The present study evaluates the role of biofilm and efflux pump activities in influencing high-level resistance in virulent P. aeruginosa strains in clinical infection. Phenotypic resistance in biotyped Pseudomonas aeruginosa (n = 147) from diagnosed disease conditions was classified based on multiple antibiotic resistance (MAR) indices and analysed with logistic regression for risk factors. Efflux pump activity, biofilm formation, and virulence factors were analysed for optimal association in Pseudomonas infection using receiver operation characteristics (ROC). Age-specificity (OR [CI] = 0.986 [0.946-1.027]), gender (OR [CI] = 1.44 [0.211-9.827]) and infection sources (OR [CI] = 0.860 [0.438-1.688]) were risk variables for multidrug resistance (MDR)-P. aeruginosa infection (p < 0.05). Biofilm formers caused 48.2% and 18.5% otorrhea and wound infections (95% CI = 0.820-1.032; p = 0.001) respectively and more than 30% multidrug resistance (MDR) strains demonstrated high-level efflux pump activity (95% CI = 0.762-1.016; p = 0.001), protease (95% CI = 0.112-0.480; p = 0.003), lipase (95% CI = 0.143-0.523; p = 0.001), and hemolysin (95% CI = 1.109-1.780; p = 0.001). Resistance relatedness of more than 80% and 60% to cell wall biosynthesis inhibitors (ceftazidime, ceffproxil, augumentin, ampicillin) and, DNA translational and transcriptional inhibitors (gentamicin, ciprofloxacin, ofloxacin, nitrofurantoin) were observed (p < 0.05). Strong efflux correlation (r = 0.85, p = 0.034) with MDR strains, with high predictive performances in efflux pump activity (ROC-AUC 0.78), biofilm formation (ROC-AUC 0.520), and virulence hierarchical-clustering. Combine activities of the expressed efflux pump and biofilm formation in MDR-P. aeruginosa pose risk to clinical management and infection control.}, }
@article {pmid36978490, year = {2023}, author = {Rajapaksha, DC and Edirisinghe, SL and Nikapitiya, C and Whang, I and De Zoysa, M}, title = {The Antimicrobial Peptide Octopromycin Suppresses Biofilm Formation and Quorum Sensing in Acinetobacter baumannii.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/antibiotics12030623}, pmid = {36978490}, issn = {2079-6382}, abstract = {Acinetobacter baumannii is an opportunistic bacterial pathogen that causes severe infections in immunocompromised individuals. A. baumannii forms biofilm and produces extracellular matrix, which supports bacteria to survive under harsh conditions and be resistant to antibacterial treatments. In the present study, we investigated the biofilm and quorum-sensing inhibitory effects of antimicrobial peptide, octopromycin in A. baumannii. Field emission-scanning electron microscopy results clearly showed significantly reduced biofilm mass and caused a collapse in biofilm architecture at the minimum inhibitory concentration (50 µg/mL) and minimum bactericidal concentration (200 µg/mL) of octopromycin. Antibiotic-resistant persister cells of A. baumannii were successfully killed by octopromycin treatment, and it inhibited violacein production in Chromobacterium violaceum in a concentration-dependent manner. Octopromycin also inhibited alginate production, surface movements (swarming and swimming), and twitching motility of A. baumannnii, confirming its anti-quorum-sensing activity. Multiple metabolic pathways, two-component regulation systems, quorum-sensing, and antibiotic synthesis-related pathways in A. baumannii biofilms were strongly affected by octopromycin treatment. The collective findings indicate that the antibacterial peptide octopromycin may control A. baumannii biofilms through multi-target interactions. Octopromycin could be a desirable therapeutic option for the prevention and control of A. baumannii infections.}, }
@article {pmid36978452, year = {2023}, author = {Kuppusamy, R and Yasir, M and Yu, TT and Voli, F and Vittorio, O and Miller, MJ and Lewis, P and Black, DS and Willcox, M and Kumar, N}, title = {Tuning the Anthranilamide Peptidomimetic Design to Selectively Target Planktonic Bacteria and Biofilm.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/antibiotics12030585}, pmid = {36978452}, issn = {2079-6382}, abstract = {There is a pressing need to develop new antimicrobials to help combat the increase in antibiotic resistance that is occurring worldwide. In the current research, short amphiphilic antibacterial and antibiofilm agents were produced by tuning the hydrophobic and cationic groups of anthranilamide peptidomimetics. The attachment of a lysine cationic group at the tail position increased activity against E. coli by >16-fold (from >125 μM to 15.6 μM) and greatly reduced cytotoxicity against mammalian cells (from ≤20 μM to ≥150 μM). These compounds showed significant disruption of preformed biofilms of S. aureus at micromolar concentrations.}, }
@article {pmid36978412, year = {2023}, author = {Praseetha, S and Sukumaran, ST and Dan, M and Augustus, AR and Pandian, SK and Sugathan, S}, title = {The Anti-Biofilm Potential of Linalool, a Major Compound from Hedychium larsenii, against Streptococcus pyogenes and Its Toxicity Assessment in Danio rerio.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/antibiotics12030545}, pmid = {36978412}, issn = {2079-6382}, abstract = {The anti-biofilm and anti-virulence potential of the essential oil (E.O.) extracted from Hedychium larsenii M. Dan &amp; Sathish was determined against Streptococcus pyogenes. A crystal violet assay was employed to quantify the biofilm. Linalool, a monoterpene alcohol from the E.O., showed concentration-dependent biofilm inhibition, with a maximum of 91% at a concentration of 0.004% (v/v). The AlamarBlue[TM] assay also confirmed Linalool's non-bactericidal anti-biofilm efficacy (0.004%). Linalool treatment impeded micro-colony formation, mature biofilm architecture, surface coverage, and biofilm thickness and impaired cell surface hydrophobicity and EPS production. Cysteine protease synthesis was quantified using the Azocasein assay, and Linalool treatment augmented its production. This suggests that Linalool destabilizes the biofilm matrix. It altered the expression of core regulons covRS, mga, srv, and ropB, and genes associated with virulence and biofilm formation, such as speB, dltA, slo, hasA, and ciaH, as revealed by qPCR analysis. Cytotoxicity analysis using human kidney cells (HEK) and the histopathological analysis in Danio rerio proved Linalool to be a druggable molecule against the biofilms formed by S. pyogenes. This is the first report on Linalool's anti-biofilm and anti-virulence potential against S. pyogenes.}, }
@article {pmid36978402, year = {2023}, author = {Regulski, M and Myntti, MF and James, GA}, title = {Anti-Biofilm Efficacy of Commonly Used Wound Care Products in In Vitro Settings.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/antibiotics12030536}, pmid = {36978402}, issn = {2079-6382}, abstract = {Considering the prevalence and pathogenicity of biofilms in wounds, this study was designed to evaluate the anti-biofilm capabilities of eight commercially available wound care products using established in vitro assays for biofilms. The products evaluated included dressings with multiple delivery formats for ionic silver including nanocrystalline, gelling fibers, polyurethane (PU) foam, and polymer matrix. Additionally, non-silver-based products including an extracellular polymeric substance (EPS)-dissolving antimicrobial wound gel (BDWG), a collagenase-based debriding ointment and a fish skin-based skin substitute were also evaluated. The products were evaluated on Staphylococcus aureus and Pseudomonas aeruginosa mixed-species biofilms grown using colony drip flow reactor (CDFR) and standard drip flow reactor (DFR) methodologies. Anti-biofilm efficacy was measured by viable plate counts and confocal scanning laser microscopy (CSLM). Four of the eight wound care products tested were efficacious in inhibiting growth of new biofilm when compared with untreated controls. These four products were further evaluated against mature biofilms. BDWG was the only product that achieved greater than 2-log growth reduction (5.88 and 6.58 for S. aureus and P. aeruginosa, respectively) of a mature biofilm. Evaluating both biofilm prevention and mature biofilm disruption capacity is important to a comprehensive understanding of the anti-biofilm efficacy of wound care products.}, }
@article {pmid36978347, year = {2023}, author = {Bomfim de Barros, D and de Oliveira E Lima, L and Alves da Silva, L and Cavalcante Fonseca, M and Ferreira, RC and Diniz Neto, H and da Nóbrega Alves, D and da Silva Rocha, WP and Scotti, L and de Oliveira Lima, E and Vieira Sobral, M and Cançado Castellano, LR and Moura-Mendes, J and Queiroga Sarmento Guerra, F and da Silva, MV}, title = {α-Pinene: Docking Study, Cytotoxicity, Mechanism of Action, and Anti-Biofilm Effect against Candida albicans.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/antibiotics12030480}, pmid = {36978347}, issn = {2079-6382}, abstract = {Candida albicans is associated with serious infections in immunocompromised patients. Terpenes are natural-product derivatives, widely studied as antifungal alternatives. In a previous study reported by our group, the antifungal activity of α-pinene against C. albicans was verified; α-pinene presented an MIC between 128-512 µg/mL. In this study, we evaluate time-kill, a mechanism of action using in silico and in vitro tests, anti-biofilm activity against the Candida albicans, and toxicity against human cells (HaCaT). Results from the molecular-docking simulation demonstrated that thymidylate synthase (-52 kcal mol[-1]), and δ-14-sterol reductase (-44 kcal mol[-1]) presented the best interactions. Our in vitro results suggest that α-pinene's antifungal activity involves binding to ergosterol in the cellular membrane. In the time-kill assay, the antifungal activity was not time-dependent, and also inhibited biofilm formation, while rupturing up to 88% of existing biofilm. It was non-cytotoxic to human keratinocytes. Our study supports α-pinene as a candidate to treat fungal infections caused by C. albicans.}, }
@article {pmid36978196, year = {2023}, author = {Li, F and Huang, K and Wang, J and Yuan, K and Yang, Y and Liu, Y and Zhou, X and Kong, K and Yang, T and He, J and Liu, C and Ao, H and Liu, F and Liu, Q and Tang, T and Yang, S}, title = {A dual functional Ti-Ga alloy: inhibiting biofilm formation and osteoclastogenesis differentiation via disturbing iron metabolism.}, journal = {Biomaterials research}, volume = {27}, number = {1}, pages = {24}, pmid = {36978196}, issn = {1226-4601}, abstract = {BACKGROUND: Although biomedical implants have been widely used in orthopedic treatments, two major clinical challenges remain to be solved, one is the bacterial infection resulting in biofilm formation, and the other is aseptic loosening during implantation due to over-activated osteoclastogenesis. These factors can cause many clinical issues and even lead to implant failure. Thus, it is necessary to endow implants with antibiofilm and aseptic loosening-prevention properties, to facilitate the integration between implants and bone tissues for successful implantation. To achieve this goal, this study aimed to develop a biocompatible titanium alloy with antibiofilm and anti-aseptic loosening dual function by utilizing gallium (Ga) as a component.<br><br>METHODS: A series of Ti-Ga alloys were prepared. We examined the Ga content, Ga distribution, hardness, tensile strength, biocompatibility, and anti-biofilm performance in vitro and in vivo. We also explored how Ga[3+] ions inhibited the biofilm formation of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) and osteoclast differentiation.<br><br>RESULTS: The alloy exhibited outstanding antibiofilm properties against both S. aureus and E. coli in vitro and decent antibiofilm performance against S. aureus in vivo. The proteomics results demonstrated that Ga[3+] ions could disturb the bacterial Fe metabolism of both S. aureus and E. coli, inhibiting bacterial biofilm formation. In addition, Ti-Ga alloys could inhibit receptor activator of nuclear factor-&#x3ba;B ligand (RANKL)-dependent osteoclast differentiation and function by targeting iron metabolism, then suppressing the activation of the NF-&#x3ba;B signaling pathway, thus, showing their potential to prevent aseptic loosening.<br><br>CONCLUSION: This study provides an advanced Ti-Ga alloy that can be used as a promising orthopedic implant raw material for various clinical scenarios. This work also revealed that iron metabolism is the common target of Ga[3+] ions to inhibit biofilm formation and osteoclast differentiation.}, }
@article {pmid36976452, year = {2023}, author = {Ebrahimi, MT and Hedayati, MA and Pirlar, RF and Mortazavi, N and Nazari, M and Ahmadi, A and Hemmati, J and Erfani, Y}, title = {Investigation of the biofilm formation in extra-intestinal pathogenic Escherichia coli ST131 strains and its correlation with the presence of fimH, afa, and kpsMSTII genes.}, journal = {Journal of applied genetics}, volume = {}, number = {}, pages = {}, pmid = {36976452}, issn = {2190-3883}, abstract = {Escherichia coli sequence type 131 (ST131) is a multidrug-resistant strain with the global dissemination. Biofilm formation-related factors include the most important virulence factors in extra-intestinal pathogenic E. coli (ExPEC) ST131 strains causing infections with treatment-limited subjects. This study aims to investigate the biofilm formation ability and its correlation with the presence of fimH, afa, and kpsMSTII genes in clinical isolates of ExPEC ST131. In this regard, the prevalence and characteristics of these strains collected and evaluated. The results revealed strong, moderate, and weak attachment abilities related to biofilm formation attributes in 45%, 20%, and 35% of strains, respectively. In the meantime, the frequency of the fimH, afa, and kpsMSTII genes among the isolates was observed as follows: fimH positive: 65%; afa positive: 55%; and kpsMSTII positive: 85%. The results convey a significant different of biofilm formation ability between clinical E. coli ST131 and non-ST131 isolates. Furthermore, while 45% of ST131 isolates produced strong biofilms, only 2% of non-ST131 isolates showed the ability to form strong biofilms. The attending of fimH, afa, and kpsMSTII genes in the majority of ST131 strains demonstrated a key role leading to biofilm formation. These findings suggested the application of fimH, afa, and kpsMSTII gene suppressors for treating biofilm infections caused by drug-resistant ST131 strains.}, }
@article {pmid36972823, year = {2023}, author = {Wang, M and Muhammad, T and Gao, H and Liu, J and Liang, H}, title = {Targeted pH-responsive chitosan nanogels with Tanshinone IIA for enhancing the antibacterial/anti-biofilm efficacy.}, journal = {International journal of biological macromolecules}, volume = {}, number = {}, pages = {124177}, doi = {10.1016/j.ijbiomac.2023.124177}, pmid = {36972823}, issn = {1879-0003}, abstract = {Persistent bacterial infection caused by biofilms is one of the most serious problems that threatened human health. The development of antibacterial agents remains a challenge to penetrate biofilm and effectively treat the underlying bacterial infection. In the current study, chitosan-based nanogels were developed for encapsulating the Tanshinone IIA (TA) to enhance the antibacterial and anti-biofilm efficacy against Streptococcus mutans (S. mutans). The as-prepared nanogels (TA@CS) displayed excellent encapsulation efficiency (91.41 ± 0.11 %), uniform particle sizes (393.97 ± 13.92 nm), and enhanced positive potential (42.27 ± 1.25 mV). After being coated with CS, the stability of TA under light and other harsh environments was greatly improved. In addition, TA@CS displayed pH responsiveness, allowing it to selectively release more TA in acidic conditions. Furthermore, the positively charged TA@CS were equipped to target negatively charged biofilm surfaces and efficiently penetrate through biofilm barriers, making it promising for remarkable anti-biofilm activity. More importantly, when TA was encapsulated into CS nanogels, the antibacterial activity of TA was enhanced at least 4-fold. Meanwhile, TA@CS inhibited 72 % of biofilm formation at 500 μg/mL. The results demonstrated that the nanogels constituted CS and TA had antibacterial/anti-biofilm properties with synergistic enhanced effects, which will benefit pharmaceutical, food, and other fields.}, }
@article {pmid36972812, year = {2023}, author = {Tian, H and Li, Y and Chen, H and Zhang, J and Hui, M and Xu, X and Su, Q and Smets, BF}, title = {Aerobic biodegradation of quinoline under denitrifying conditions in membrane-aerated biofilm reactor.}, journal = {Environmental pollution (Barking, Essex : 1987)}, volume = {326}, number = {}, pages = {121507}, doi = {10.1016/j.envpol.2023.121507}, pmid = {36972812}, issn = {1873-6424}, abstract = {Aerobic denitrification is being investigated as a novel biological nitrogen removal process, yet the knowledge on aerobic denitrification is limited to pure culture isolations and its occurrence in bioreactors remains unclear. This study investigated the feasibility and capacity of applying aerobic denitrification in membrane aerated biofilm reactor (MABR) for biological treatment of quinoline-laden wastewater. Stable and efficient removals of quinoline (91.5 ± 5.2%) and nitrate (NO3[-]) (86.5 ± 9.3%) were obtained under different operational conditions. Enhanced formation and function of extracellular polymeric substances (EPS) were observed at increasing quinoline loadings. MABR biofilm was highly enriched with aerobic quinoline-degrading bacteria, with a predominance of Rhodococcus (26.9 ± 3.7%) and secondary abundance of Pseudomonas (1.7 ± 1.2%) and Comamonas (0.94 ± 0.9%). Metagenomic analysis indicated that Rhodococcus contributed significantly to both aromatic degradation (24.5 ± 21.3%) and NO3[-] reduction (4.5 ± 3.9%), indicating its key role in aerobic denitrifying quinoline biodegradation. At increasing quinoline loadings, abundances of aerobic quinoline degradation gene oxoO and denitrifying genes of napA, nirS and nirK increased; there was a significant positive correlation of oxoO with nirS and nirK (p < 0.05). Aerobic quinoline degradation was likely initiated by hydroxylation, encoded by oxoO, followed by stepwise oxidations through 5,6-dihydroxy-1H-2-oxoquinoline or 8-hydroxycoumarin pathway. The results advance our understanding of quinoline degradation during biological nitrogen removal, and highlight the potential implementation of aerobic denitrification driven quinoline biodegradation in MABR for simultaneous removal of nitrogen and recalcitrant organic carbon from coking, coal gasification and pharmaceutical wastewaters.}, }
@article {pmid36972615, year = {2023}, author = {de Oliveira Martinez, JP and Vazquez, L and Takeyama, MM and Dos Santos Filho, TJ and Cavalcante, FS and Guimarães, LC and Pereira, EM and Dos Santos, KRN}, title = {Novel biochemical aspects of lugdulysin, a Staphylococcus lugdunensis metalloprotease that inhibits formation and disrupts protein biofilm of methicillin-resistant Staphylococcus aureus.}, journal = {Bioscience, biotechnology, and biochemistry}, volume = {}, number = {}, pages = {}, doi = {10.1093/bbb/zbad035}, pmid = {36972615}, issn = {1347-6947}, abstract = {Staphylococcus lugdunensis produces lugdulysin, a metalloprotease that may contribute to its virulence. This study aimed to evaluate the biochemical aspects of lugdulysin and investigate its effect on Staphylococcus aureus biofilms. The protease was isolated and characterized for its optimal pH and temperature, hydrolysis kinetics, and influence of metal cofactor supplementation. The protein structure was determined via homology modelling. The effect on S. aureus biofilms was assessed by the micromethod technique. The protease optimal pH and temperature were 7.0 and 37°C, respectively. EDTA inhibited protease activity, confirming it as a metalloprotease. Lugdulysin activity was not recovered by divalent ion supplementation post-inhibition and supplementation with divalent ions did not change enzymatic activity. The isolated enzyme was stable for up to 3 hours. Lugdulysin significantly inhibited the formation and disrupted pre-established protein-matrix MRSA biofilm. This preliminary study indicates that lugdulysin has a potential role as a competition mechanism and/or modulation of staphylococcal biofilm.}, }
@article {pmid36971546, year = {2023}, author = {Yahya, AH and Harston, SR and Colton, WL and Cabeen, MT}, title = {Distinct Screening Approaches Uncover PA14_36820 and RecA as Negative Regulators of Biofilm Phenotypes in Pseudomonas aeruginosa PA14.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0377422}, doi = {10.1128/spectrum.03774-22}, pmid = {36971546}, issn = {2165-0497}, abstract = {Pseudomonas aeruginosa commonly infects hospitalized patients and the lungs of individuals with cystic fibrosis. This species is known for forming biofilms, which are communities of bacterial cells held together and encapsulated by a self-produced extracellular matrix. The matrix provides extra protection to the constituent cells, making P. aeruginosa infections challenging to treat. We previously identified a gene, PA14_16550, which encodes a DNA-binding TetR-type repressor and whose deletion reduced biofilm formation. Here, we assessed the transcriptional impact of the 16550 deletion and found six differentially regulated genes. Among them, our results implicated PA14_36820 as a negative regulator of biofilm matrix production, while the remaining 5 had modest effects on swarming motility. We also screened a transposon library in a biofilm-impaired ΔamrZ Δ16550 strain for restoration of matrix production. Surprisingly, we found that disruption or deletion of recA increased biofilm matrix production, both in biofilm-impaired and wild-type strains. Because RecA functions both in recombination and in the DNA damage response, we asked which function of RecA is important with respect to biofilm formation by using point mutations in recA and lexA to specifically disable each function. Our results implied that loss of either function of RecA impacts biofilm formation, suggesting that enhanced biofilm formation may be one physiological response of P. aeruginosa cells to loss of either RecA function. IMPORTANCE Pseudomonas aeruginosa is a notorious human pathogen well known for forming biofilms, communities of bacteria that protect themselves within a self-secreted matrix. Here, we sought to find genetic determinants that impacted biofilm matrix production in P. aeruginosa strains. We identified a largely uncharacterized protein (PA14_36820) and, surprisingly, RecA, a widely conserved bacterial DNA recombination and repair protein, as negatively regulating biofilm matrix production. Because RecA has two main functions, we used specific mutations to isolate each function and found that both functions influenced matrix production. Identifying negative regulators of biofilm production may suggest future strategies to reduce the formation of treatment-resistant biofilms.}, }
@article {pmid36971485, year = {2023}, author = {Ousey, K and Ovens, L}, title = {Comparing methods of debridement for removing biofilm in hard-to-heal wounds.}, journal = {Journal of wound care}, volume = {32}, number = {Sup3b}, pages = {S4-S10}, doi = {10.12968/jowc.2023.32.Sup3b.S4}, pmid = {36971485}, issn = {0969-0700}, mesh = {Humans ; Debridement/methods ; *Wound Healing ; *Wound Infection/therapy ; Biofilms ; }, }
@article {pmid36970701, year = {2023}, author = {Aljohani, AM and El-Chami, C and Alhubail, M and Ledder, RG and O'Neill, CA and McBain, AJ}, title = {Escherichia coli Nissle 1917 inhibits biofilm formation and mitigates virulence in Pseudomonas aeruginosa.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1108273}, pmid = {36970701}, issn = {1664-302X}, abstract = {In the quest for mitigators of bacterial virulence, cell-free supernatants (CFS) from 25 human commensal and associated bacteria were tested for activity against Pseudomonas aeruginosa. Among these, Escherichia coli Nissle 1917 CFS significantly inhibited biofilm formation and dispersed extant pseudomonas biofilms without inhibiting planktonic bacterial growth. eDNA was reduced in biofilms following exposure to E. coli Nissle CFS, as visualized by confocal microscopy. E. coli Nissle CFS also showed a significant protective effect in a Galleria mellonella-based larval virulence assay when administrated 24 h before challenge with the P. aeruginosa. No inhibitory effects against P. aeruginosa were observed for other tested E. coli strains. According to proteomic analysis, E. coli Nissle CFS downregulated the expression of several P. aeruginosa proteins involved in motility (Flagellar secretion chaperone FliSB, B-type flagellin fliC, Type IV pilus assembly ATPase PilB), and quorum sensing (acyl-homoserine lactone synthase lasI and HTH-type quorum-sensing regulator rhlR), which are associated with biofilm formation. Physicochemical characterization of the putative antibiofilm compound(s) indicates the involvement of heat-labile proteinaceous factors of greater than 30 kDa molecular size.}, }
@article {pmid36969800, year = {2023}, author = {Delaney, C and Short, B and Rajendran, R and Kean, R and Burgess, K and Williams, C and Munro, CA and Ramage, G}, title = {An integrated transcriptomic and metabolomic approach to investigate the heterogeneous Candida albicans biofilm phenotype.}, journal = {Biofilm}, volume = {5}, number = {}, pages = {100112}, pmid = {36969800}, issn = {2590-2075}, abstract = {Candida albicans is the most prevalent and notorious of the Candida species involved in bloodstream infections, which is characterised by its capacity to form robust biofilms. Biofilm formation is an important clinical entity shown to be highly variable among clinical isolates. There are various environmental and physiological factors, including nutrient availability which influence the phenotype of Candida species. However, mechanisms underpinning adaptive biofilm heterogeneity have not yet been fully explored. Within this study we have profiled previously characterised and phenotypically distinct C. albicans bloodstream isolates. We assessed the dynamic susceptibility of these differing populations to antifungal treatments using population analysis profiling in addition to assessing biofilm formation and morphological changes. High throughput methodologies of RNA-Seq and LC-MS were employed to map and integrate the transcriptional and metabolic reprogramming undertaken by heterogenous C. albicans isolates in response to biofilm and hyphal inducing serum. We found a significant relationship between biofilm heterogeneity and azole resistance (P < 0.05). In addition, we observed that in response to serum our low biofilm forming (LBF) C. albicans exhibited a significant increase in biofilm formation and hyphal elongation. The transcriptional reprogramming of LBF strains compared to high biofilm forming (HBF) was distinct, indicating a high level of plasticity and variation in stress responses by heterogenous strains. The metabolic responses, although variable between LBF and HBF, shared many of the same responses to serum. Notably, a high upregulation of the arachidonic acid cascade, part of the COX pathway, was observed and this pathway was found to induce biofilm formation in LBF 3-fold. C. albicans is a highly heterogenous bloodstream pathogen with clinical isolates varying in antifungal tolerance and biofilm formation. In addition to this, C. albicans is capable of highly complex and variable regulation of transcription and metabolic pathways and heterogeneity across isolates further increases the complexity of these pathways. Here we have shown with a dual and integrated approach, the importance of studying a diverse panel of C. albicans isolates, which has the potential to reveal distinct pathways that can harnessed for drug discovery.}, }
@article {pmid36969455, year = {2023}, author = {Kang, MG and Khan, F and Tabassum, N and Cho, KJ and Jo, DM and Kim, YM}, title = {Inhibition of Biofilm and Virulence Properties of Pathogenic Bacteria by Silver and Gold Nanoparticles Synthesized from Lactiplantibacillus sp. Strain C1.}, journal = {ACS omega}, volume = {8}, number = {11}, pages = {9873-9888}, pmid = {36969455}, issn = {2470-1343}, abstract = {The emergence of antibiotic resistance in microbial pathogens necessitates the development of alternative ways to combat the infections that arise. The current study used nanotechnology as an alternate technique to control virulence characteristics and biofilm development in Pseudomonas aeruginosa and Staphylococcus aureus. Furthermore, based on the acceptance and biocompatibility of the probiotic bacteria, we chose a lactic acid bacteria (LAB) for synthesizing two types of metallic nanoparticles (NPs) in this study. Using molecular techniques, the LAB strain C1 was isolated from Kimchi food samples and identified as Lactiplantibacillus sp. strain C1. The prepared supernatant from strain C1 was used to produce gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs). C1-AuNPs and C1-AgNPs were characterized physiochemically using a variety of instruments. C1-AuNPs and C1-AgNPs had spherical shapes and sizes of 100.54 ± 14.07 nm (AuNPs) and 129.51 ± 12.31 nm (AgNPs), respectively. C1-AuNPs and C1-AgNPs were discovered to have high zeta potentials of -23.29 ± 1.17 and -30.57 ± 0.29 mV, respectively. These nanoparticles have antibacterial properties against several bacterial pathogens. C1-AuNPs and C1-AgNPs significantly inhibited the initial stage biofilm formation and effectively eradicated established mature biofilms of P. aeruginosa and S. aureus. Furthermore, when P. aeruginosa was treated with sub-MIC levels of C1-AuNPs and C1-AgNPs, their different virulence features were significantly reduced. Both NPs greatly inhibited the hemolytic activity of S. aureus. The inhibition of P. aeruginosa and S. aureus biofilms and virulence features by C1-AuNPs and C1-AgNPs can be regarded as viable therapeutic strategies for preventing infections caused by these bacteria.}, }
@article {pmid36968011, year = {2023}, author = {Nguyen, HTT and Nguyen, TH and Otto, M}, title = {Corrigendum to "The staphylococcal exopolysaccharide PIA - Biosynthesis and role in biofilm formation, colonization, and infection" [Comput Struct Biotechnol J 4/18 (2020) 3324-3334].}, journal = {Computational and structural biotechnology journal}, volume = {21}, number = {}, pages = {2035}, doi = {10.1016/j.csbj.2023.03.012}, pmid = {36968011}, issn = {2001-0370}, abstract = {[This corrects the article DOI: 10.1016/j.csbj.2020.10.027.].}, }
@article {pmid36967885, year = {2023}, author = {He, C and Li, B and Gong, Z and Huang, S and Liu, X and Wang, J and Xie, J and Shi, T}, title = {Polyphosphate kinase 1 is involved in formation, the morphology and ultramicrostructure of biofilm of Mycobacterium smegmatis and its survivability in macrophage.}, journal = {Heliyon}, volume = {9}, number = {3}, pages = {e14513}, pmid = {36967885}, issn = {2405-8440}, abstract = {The most unique characteristic of Mycobacterium tuberculosis is persistence in the human host, and the biofilm formation is related to the persistance. Polyphosphate (polyP) kinase 1 (PPK1) is conserved in Mycobacteria and is responsible for polyP synthesis. polyP is a chain molecule linked by high-energy phosphate bonds, which is considered to play a very important role in bacterial persistence. However, the relationship of PPK1 and mycobacterial biofilm formation is still adequately unclear. In current study, ppk1-deficient mutant (MT), ppk1-complemented (CT) and wild-type strains of M. smegmatis mc[2] 155 were used to investigate the formation, morphology and ultramicrostructure of the biofilm and to analyze the lipid levels and susceptibility to vancomycin antibiotic. And then WT, MT and CT strains were used to infect macrophages and to analyze the expression levels of various inflammatory factors, respectively. We found that PPK1 was required for M. smegmatis polyP production in vivo and polyP deficiency not only attenuated the biofilm formation, but also altered the phenotype and ultramicrostructure of the biofilm and reduced the cell lipid composition (except for C16.1 and C17.1, most of the fatty acid components from C8-C24). Moreover, the ppk1-deficient mutant was also significantly more sensitive to vancomycin which targets the cell wall, and its ability to survive in macrophages was decreased, which was related to the change of the expression level of inflammatory factors in macrophage. This study demonstrates that the PPK1 can affect the biofilm structure through affecting the content of short chain fatty acid and promote intracellular survival of M. smegmatis by altering the expression of inflammatory factors. These findings establish a basis for investigating the role of PPK1 in the persistence of M. tuberculosis, and provide clues for treating latent infection of M. tuberculosis with PPK1 as a potential drug target.}, }
@article {pmid36967503, year = {2023}, author = {Majeed, N and Ismail, F}, title = {In vitro characteristics of fungal biofilm formation and the influence of physiological stress on biofilm growth.}, journal = {Pakistan journal of pharmaceutical sciences}, volume = {36}, number = {1}, pages = {103-109}, pmid = {36967503}, issn = {1011-601X}, abstract = {Fungal biofilms are a growing clinical concern associated with high mortality rates. This study included three fungal groups, dimorphic fungi (Candida albicans), Dermatophytes (Trichophyton mentagrophytes) and non-dermatophytes (Acremonium sclerotigenum, Aspergillus niger). This research describes the in vitro characteristics of biofilm formation in three fungal groups. The influence of osmotic, oxidative and pH stress environment on biofilm growth was also focused. Biofilm characteristics in A. sclerotigenum and A. niger were studied for the first time. In vitro qualitative and quantitative approaches were used to evaluate biofilm development including the test tube method, tissue culture plate method in addition to staining with crystal violet and safranin. All the isolates were able to form biofilm. Biofilm development under different pH range showed maximum growth at neutral pH. At a concentration of 5mM hydrogen peroxide and 2M NaCl biofilm formation was maximum for all three fungal groups under an oxidative and osmotic stress respectively. Study revealed that biofilm production was increased under osmotic and oxidative stress. All isolates respond to oxidative and osmotic stress by changing the cell wall composition with a rich exopolymeric matrix in order to survive in stress environment.}, }
@article {pmid36966927, year = {2023}, author = {Liu, Q and Hou, J and Zeng, Y and Wu, J and Miao, L and Yang, Z}, title = {Fabrication of an intimately coupled photocatalysis and biofilm system for removing sulfamethoxazole from wastewater: Effectiveness, degradation pathway and microbial community analysis.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {138507}, doi = {10.1016/j.chemosphere.2023.138507}, pmid = {36966927}, issn = {1879-1298}, abstract = {Sulfamethoxazole (SMX) is an extensively applied antibiotic frequently detected in municipal wastewater, which cannot be efficiently removed by conventional biological wastewater processes. In this work, an intimately coupled photocatalysis and biodegradation (ICPB) system consisting of Fe[3+]-doped graphitic carbon nitride photocatalyst and biofilm carriers was fabricated to remove SMX. The results of wastewater treatment experiments showed that 81.2 ± 2.1% of SMX was removed in the ICPB system during the 12 h, while only 23.7 ± 4.0% was removed in the biofilm system within the same time. In the ICPB system, photocatalysis played a key role in removing SMX by producing hydroxyl radicals and superoxide radicals. Besides, the synergism between photocatalysis and biodegradation enhanced the mineralization of SMX. To understand the degradation process of SMX, nine degradation products and possible degradation pathways of SMX were analyzed. The results of high throughput sequencing showed that the diversity, abundance, and structure of the biofilm microbial community remained stable in the ICPB system at the end of the experiments, which suggested that microorganisms had accommodated to the environment of the ICPB system. This study could provide insights into the application of the ICPB system in treating antibiotic-contaminated wastewater.}, }
@article {pmid36966821, year = {2023}, author = {Zhang, H and Gong, W and Xue, Y and Zeng, W and Wang, H and Wang, J and Tang, X and Li, G and Liang, H}, title = {Municipal wastewater contains antibiotic treatment using O2 transfer membrane based biofilm reactor: Interaction between regular pollutants metabolism and sulfamethoxazole degradation.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {163060}, doi = {10.1016/j.scitotenv.2023.163060}, pmid = {36966821}, issn = {1879-1026}, abstract = {The antibiotic sulfamethoxazole (SMX) is frequently detected in wastewater treatment plant effluents and has attracted significant attention owing to its significant potential environmental effects. We present a novel O2 transfer membrane based biofilm reactor (O2TM-BR) to treat municipal wastewater to eliminate containing SMX. Furthermore, conducting metagenomics analyses, the interactions in biodegradation process between SMX and regular pollutants (NH4[+]-N and COD) were studied. Results suggest that O2TM-BR yields evident advantages in SMX degradation. Increasing SMX concentrations did not affect the efficiency of the system, and the effluent concentration remained consistent at approximately 17.0 μg/L. The interaction experiment showed that heterotrophic bacteria tend to consume easily degradable COD for metabolism, resulting in a delay (>36 h) in complete SMX degradation, which is 3-times longer than without COD. It is worth noting that the taxonomic and functional structure and composition in nitrogen metabolism were significantly shifted upon the SMX. NH4[+]-N removal remained unaffected by SMX in O2TM-BR, and the expression of K10944 and K10535 has no significant difference under the stress of SMX (P > 0.02). However, the K00376 and K02567 required in the nitrate reductase is inhibited by SMX (P < 0.01), which hinders the reduction of NO3[-]-N and hence the accumulation of TN. This study provides a new method for SMX treatment and reveals the interaction between SMX and conventional pollutants in O2TM-BR as well as the microbial community function and assembly mechanism.}, }
@article {pmid36965588, year = {2023}, author = {Zhong, J and Liu, J and Hu, R and Pan, D and Shao, S and Wu, X}, title = {Performance of nitrification-denitrification and denitrifying phosphorus removal driven by in-situ generated biogenic manganese oxides in a moving bed biofilm reactor.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {128957}, doi = {10.1016/j.biortech.2023.128957}, pmid = {36965588}, issn = {1873-2976}, abstract = {Simultaneous removal of NH4[+]-N, NO3[-]-N, COD, and P by manganese redox cycling in nutrient wastewater was established with two moving bed biofilm reactors (MBBRs) with in-situ generated biogenic manganese oxides (BioMnOx) and non-BioMnOx. In-situ generated BioMnOx preferentially promoted the denitrification, and the average removal of NO3[-]-N, NH4[+]-N, and TN in the experimental MBBR with BioMnOx increased to 89.00%, 70.64%, and 76.06% compared with the control MBBR with non-BioMnOx. The relevant enzymes activity, extracellular polymeric substance (EPS), electron transport system activity (ETSA), and reactive oxygen species (ROS) were investigated. The element valence and morphology of purified BioMnOx were characterized by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM), as well as the effect of BioMnOx on nitrogen and phosphorus removal. The results suggested that BioMnOx could improve nitrogen conversion. Electrochemical characteristic and microbial community were detected. This study provided a new strategy for nutrients removal in BioMnOx-mediated wastewater treatment.}, }
@article {pmid36965431, year = {2023}, author = {Gao, S and Sun, Y and Lu, Z and Jiang, N and Yao, H}, title = {Synergistic antibacterial and biofilm eradication activity of quaternary-ammonium compound with copper ion.}, journal = {Journal of inorganic biochemistry}, volume = {243}, number = {}, pages = {112190}, doi = {10.1016/j.jinorgbio.2023.112190}, pmid = {36965431}, issn = {1873-3344}, abstract = {Antibiotics overuse and misuse increase the emergence of multidrug-resistant bacterial strains, which often leads to the failure of conventional antibiotic therapies. Even worse, the tendency of bacteria to form biofilms further increases the therapeutic difficulty, because the extracellular matrix prevents the penetration of antibiotics and triggers bacterial tolerance. Therefore, developing novel antibacterial agents or therapeutic strategies with diverse antibacterial mechanisms and destruction of bacteria biofilm is a promising way to combat bacterial infections. In the present study, the combination of quaternary ammonium compound poly(diallyl dimethyl ammonium chloride) (PDDA) with Cu[2+] was screened out to fight common pathogenic Staphylococcus aureus (S. aureus) through multi-mechanisms. This combination appeared strong synergistic antibacterial activity, and the fractional inhibitory concentration index was as low as 0.032. The synergistic antibacterial mechanism involved the destruction of the membrane function, generation of intracellular reactive oxygen, and promotion more Cu[2+] into the cytoplasm. Further, the combination of PDDA and Cu[2+] reduced the extracellular polysaccharide matrix, meanwhile killing the bacteria embedded in the biofilm. The biocompatibility study in vitro revealed this combination exhibited low cytotoxicity and hemolysis ratio even at 8 times of minimum bactericidal concentration. This work provides a novel antibacterial agents combination with higher efficiency to fight planktonic and biofilm conditions of S. aureus.}, }
@article {pmid36965425, year = {2023}, author = {Zhang, X and Ji, B and Tian, J and Liu, Y}, title = {Development, performance and microbial community analysis of a continuous-flow microalgal-bacterial biofilm photoreactor for municipal wastewater treatment.}, journal = {Journal of environmental management}, volume = {338}, number = {}, pages = {117770}, doi = {10.1016/j.jenvman.2023.117770}, pmid = {36965425}, issn = {1095-8630}, abstract = {This work reported the development, performance and microbial community of microalgal-bacterial biofilms cultivated in a continuous-flow photoreactor for municipal wastewater treatment under various conditions. Results showed that microalgal-bacterial biofilms were successfully developed at a HRT of 9 h without external aeration, with a biofilm concentration of around 4690 mg/L being achieved in the steady-state. It was found that further increase of HRT to 12 h did not improve the overall accumulation of biofilm, whereas the growth of microalgae in biofilms was faster than bacteria in the initial stage, indicated by an increased chlorophyll-a&amp;b content in biofilms. After which, the chlorophyll-a&amp;b content in biofilms gradually stabilized at the level comparable with the seed, suggesting that there was a balanced distribution of microalgae and bacteria in biofilms. About 90% of TOC, 71.4% of total nitrogen and 72.6% of phosphorus were removed by microalgal-bacterial biofilms mainly through assimilation in the steady-state photoreactor run at the HRT of 12 h with external aeration. The community analysis further revealed that Cyanobacteria and Chloroflexi were the main components, while Chlorophyta appeared to be the dominant eukaryotic algal community in biofilms. This study could offer new insights into the development of microalgal-bacterial biofilms in a continuous-flow photoreactor for sustainable low-carbon municipal wastewater treatment.}, }
@article {pmid36963701, year = {2023}, author = {Zhao, J and Dong, X and Su, H and Huang, J and Liu, Z and He, P and Zhang, D}, title = {Rapid start-up of PN/A process and efficient enrichment of functional bacteria: a novel aerobic-biofilm/anaerobic-granular nitrogen removal system (OANRS).}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {128944}, doi = {10.1016/j.biortech.2023.128944}, pmid = {36963701}, issn = {1873-2976}, abstract = {Reactor configuration, control strategy and inoculation method were key factors affecting the rapid start-up of partial nitrification/anammox (PN/A) process and the efficient enrichment of functional bacteria (anammox and ammonia oxidizing bacteria). At present, PN/A process was generally operated through single factor rather than forming a system. In this study, a novel aerobic-biofilm/anaerobic-granular nitrogen removal system (OANRS) was constructed, which consisted of a multi-stage aerobic-biofilm/anaerobic-granular baffle reactor (MOABR) and a control strategy on pH/aeration time. PN process was started within 10d, and PN/A process was started on the basis of stable PN process within 41d. The simultaneous enrichment of functional bacteria was achieved by combining the advantages of single-stage and two-stage PN/A process. The results of high-throughput sequencing showed that Candidatus Kuenenia (20.42±15.88%) was highly enriched in each compartment at day 98, and the relative abundance of Candidatus Kuenenia in the anaerobic compartment R4 was as high as 43.13%.}, }
@article {pmid36963576, year = {2023}, author = {Li, M and Perez-Calleja, P and Kim, B and Picioreanu, C and Nerenberg, R}, title = {Unique stratification of biofilm density in heterotrophic membrane-aerated biofilms: An experimental and modeling study.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {138501}, doi = {10.1016/j.chemosphere.2023.138501}, pmid = {36963576}, issn = {1879-1298}, abstract = {We consistently find a band of high cell density develop within heterotrophic membrane-aerated biofilms. This study reports and attempts to explain this unique behavior. Biofilm density affects volumetric reaction rates, biofilm growth rates, substrate diffusion, and mechanical behavior. Yet the mechanisms and dynamics of biofilm density development are poorly understood. In this study, a membrane-aerated biofilm, where O2 was supplied from the base of the biofilm and acetate from the bulk liquid, was used to explore spatial and temporal patterns of density development. Biofilm density was assessed by optical coherence tomography. After inoculation, the biofilm quickly increased in thickness, with a low density throughout. However, as the biofilm reached a stable thickness of around 1000 μm, a high-density layer developed in the biofilm interior. The layer slowly expanded over time. Oxygen microprofiles in the biofilm showed this layer coincided with the most metabolically active zone, resulting from counter-diffusing O2 and acetate. The formation of this dense layer appeared to be related to changes in growth rates. Initially, high growth rates throughout the biofilm presumably led to fast-growing, low-density biofilms. As the biofilm became thicker, and as substrates became limiting in the biofilm interior, growth rates decreased, resulting in new growth at a higher density. A 1-D mathematical model with variable biofilm density was developed by linking the rates of extracellular polymeric substances (EPS) production to the growth rate. The model captured the initial fast growth at a low density, followed by a slower, substrate-limited growth in the biofilm interior, producing a dense band within the biofilm. Together, these results suggest that low growth rates can lead to high-density zones within the interior of counter-diffusional biofilms. These findings should also be relevant to conventional, co-diffusional biofilms, although differences in density may be less obvious.}, }
@article {pmid36960491, year = {2023}, author = {Johnston, W and Rosier, BT and Carda-Diéguez, M and Paterson, M and Watson, P and Piela, K and Goulding, M and Ramage, G and Baranyia, D and Chen, T and Al-Hebshi, N and Mira, A and Culshaw, S}, title = {Longitudinal changes in subgingival biofilm composition following periodontal treatment.}, journal = {Journal of periodontology}, volume = {}, number = {}, pages = {}, doi = {10.1002/JPER.22-0749}, pmid = {36960491}, issn = {1943-3670}, abstract = {BACKGROUND: Current periodontal treatment involves instrumentation using hand and/or ultrasonic instruments, which are used either alone or in combination based on patient and clinician preference, with comparable clinical outcomes. This study sought to investigate early and later changes in the subgingival biofilm following periodontal treatment; to identify whether these changes were associated with treatment outcomes; and to investigate whether the biofilm responded differently to hand compared with ultrasonic instruments.<br><br>METHODS: This was a secondary-outcome analysis of a randomised controlled trial. Thirty-eight periodontitis patients received full-mouth subgingival instrumentation using hand (n = 20) or ultrasonic instrumentation (n = 18). Subgingival plaque was sampled at baseline and 1, 7 and 90 days following treatment. Bacterial DNA was analysed using 16S rRNA sequencing. Periodontal clinical parameters were evaluated before and after treatment.<br><br>RESULTS: Biofilm composition was comparable in both (hand and ultrasonics) treatment groups at all timepoints (all genus and species; p[adjusted]>0.05). Large-scale changes were observed within-groups across timepoints. At days 1 and 7, taxonomic diversity and dysbiosis were reduced, with an increase in health-associated genera including Streptococcus and Rothia equating to 30-40% of the relative abundance. When reassessed at day 90 a subset of samples reformed a microbiome more comparable with baseline, which was independent of instrumentation choice and residual disease.<br><br>CONCLUSIONS: Hand and ultrasonic instruments induced comparable impacts on the subgingival plaque microbiome. There were marked early changes in the subgingival biofilm composition, although there was limited evidence that community shifts associated with treatment outcomes. This article is protected by copyright. All rights reserved.}, }
@article {pmid36959476, year = {2023}, author = {Kilic, T and Bali, EB}, title = {Biofilm control strategies in the light of biofilm-forming microorganisms.}, journal = {World journal of microbiology &amp; biotechnology}, volume = {39}, number = {5}, pages = {131}, pmid = {36959476}, issn = {1573-0972}, abstract = {Biofilm is a complex consortium of microorganisms attached to biotic or abiotic surfaces and live in self-produced or acquired extracellular polymeric substances (EPSs). EPSs are mainly formed by lipids, polysaccharides, proteins, and extracellular DNAs. The adherence to the surface of microbial communities is seen in food, medical, dental, industrial, and environmental fields. Biofilm development in food processing areas challenges food hygiene, and human health. In addition, bacterial attachment and biofilm formation on medical implants inside human tissue can cause multiple critical chronic infections. More than 30 years of international research on the mechanisms of biofilm formation have been underway to address concerns about bacterial biofilm infections. Antibiofilm strategies contain cold atmospheric plasma, nanotechnological, phage-based, antimicrobial peptides, and quorum sensing inhibition. In the last years, the studies on environmentally-friendly techniques such as essential oils and bacteriophages have been intensified to reduce microbial growth. However, the mechanisms of the biofilm matrix formation are still unclear. This review aims to discuss the latest antibiofilm therapeutic strategies against biofilm-forming bacteria.}, }
@article {pmid36959215, year = {2023}, author = {Bech, PK and Zhang, SD and Henriksen, NNSE and Bentzon-Tilia, M and Strube, ML and Gram, L}, title = {The potential to produce tropodithietic acid by Phaeobacter inhibens affects the assembly of microbial biofilm communities in natural seawater.}, journal = {NPJ biofilms and microbiomes}, volume = {9}, number = {1}, pages = {12}, pmid = {36959215}, issn = {2055-5008}, abstract = {Microbial secondary metabolites play important roles in biotic interactions in microbial communities and yet, we do not understand how these compounds impact the assembly and development of microbial communities. To address the implications of microbial secondary metabolite production on biotic interactions in the assembly of natural seawater microbiomes, we constructed a model system where the assembly of a natural seawater biofilm community was influenced by the addition of the marine biofilm forming Phaeobacter inhibens that can produce the antibiotic secondary metabolite tropodithietic acid (TDA), or a mutant incapable of TDA production. Because of the broad antibiotic activity of TDA, we hypothesized that the potential of P. inhibens to produce TDA would strongly affect both biofilm and planktonic community assembly patterns. We show that 1.9 % of the microbial composition variance across both environments could be attributed to the presence of WT P. inhibens, and especially genera of the Bacteriodetes were increased by the presence of the TDA producer. Moreover, network analysis with inferred putative microbial interactions revealed that P. inhibens mainly displayed strong positive associations with genera of the Flavobacteriaceae and Alteromonadaceae, and that P. inhibens acts as a keystone OTU in the biofilm exclusively due to its potential to produce TDA. Our results demonstrate the potential impact of microbial secondary metabolites on microbial interactions and assembly dynamics of complex microbial communities.}, }
@article {pmid36950165, year = {2023}, author = {Racioppo, A and Speranza, B and Altieri, C and Sinigaglia, M and Corbo, MR and Bevilacqua, A}, title = {Ultrasound can increase biofilm formation by Lactiplantibacillus plantarum and Bifidobacterium spp.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1094671}, pmid = {36950165}, issn = {1664-302X}, abstract = {The main goal of this research was to study the effect of an Ultrasound (US) treatment on biofilm formation of Lactiplantibacillus plantarum (strains c19 and DSM 1055), Bifidobacterium animalis subsp. lactis DSM 10140, Bifidobacterium longum subsp. longum DSM 20219, and Bifidobacterium longum subsp. infantis DSM 20088. From a methodological point of view, each microorganism was treated through six US treatments, different for the power (10, 30, or 50% of the net power, 130 W), the duration (2, 6, or 10 min) and the application of pulses (0 or 10 s). After the treatment, a biofilm of the strains was let to form on glass slides and the concentration of sessile cells was analyzed for 16 days. Biofilms formed by untreated microorganisms were used as controls. As a first result, it was found that US significantly increased the concentration of sessile cells of B. longum subsp. infantis, while for some other strains US treatment could not affect the formation of biofilm while improving its stability, as found for L. plantarum DSM1055 after 16 days. The variable mainly involved in this positive effect of US was the duration of the treatment, as biofilm formation and stability were improved only for 2 min-treatments; on the other hand, the effect of power and pulses were strain-dependent. In conclusion, the results suggest practical implication of a US pre-treatment for various fields (improvement of adhesion of microorganisms useful in food or in the gut, biomedical and environmental industries), although further investigations are required to elucidate the mode of action.}, }
@article {pmid36950159, year = {2023}, author = {Liang, J and Huang, TY and Mao, Y and Li, X}, title = {Biofilm formation of two genetically diverse Staphylococcus aureus isolates under beta-lactam antibiotics.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1139753}, pmid = {36950159}, issn = {1664-302X}, abstract = {PURPOSE: Our aim was to evaluate the biofilm formation of 2 genetically diverse Staphylococcus aureus isolates, 10379 and 121940, under different concentrations of beta-lactam antibiotics on biomass content and biofilm viability.<br><br>METHODS: Biofilm formation and methicillin resistance genes were tested using PCR and multiplex PCR. PCR was combined with bioinformatics analysis to detect multilocal sequence typing (MLST) and SCCmec types, to study the genetical correlation between the tested strains. Then, the crystal violet (CV) test and XTT were used to detect biomass content and biofilm activity. Antibiotic susceptibility was tested using a broth dilution method. According to their specific MIC, different concentrations of beta-lactam antibiotics were used to study its effect on biomass content and biofilm viability.<br><br>RESULTS: Strain 10379 carried the icaD, icaBC, and MRSA genes, not the icaA, atl, app, and agr genes, and MLST and SCCmec typing was ST45 and IV, respectively. Strain 121940 carried the icaA, icaD, icaBC, atl, and agr genes, not the aap gene, and MLST and SCCmec typed as ST546 and IV, respectively. This suggested that strains 10379 and 121940 were genotypically very different. Two S. aureus isolates, 10379 and 121940, showed resistance to beta-lactam antibiotics, penicillin, ampicillin, meropenem, streptomycin and kanamycin, some of which promoted the formation of biofilm and biofilm viability at low concentrations.<br><br>CONCLUSION: Despite the large differences in the genetic background of S. aureus 10379 and 121940, some sub-inhibitory concentrations of beta-lactam antibiotics are able to promote biomass and biofilm viability of both two isolates.}, }
@article {pmid36948593, year = {2023}, author = {Wang, M and Wang, J and Li, T and Bao, X and Li, P and Zhang, X and Huang, Q and Meng, X and Li, S}, title = {Penicillin-binding protein 1b encoded by mrcB gene mediates the enhancement of biofilm formation by sub-inhibitory concentrations of cefotaxime in monophasic Salmonella Typhimurium strain SH16SP46.}, journal = {FEMS microbiology letters}, volume = {}, number = {}, pages = {}, doi = {10.1093/femsle/fnad021}, pmid = {36948593}, issn = {1574-6968}, abstract = {Development of cefotaxime-resistance and biofilm formation increase the difficulty to prevent and control the infection and contamination of Salmonella, one of the most important foodborne and zoonotic bacterial pathogen. Our previous study observed that 1/8 MIC of cefotaxime induced the enhancement of biofilm formation and filamentous morphological change by a monophasic Salmonella Typhimurium strain SH16SP46. This study was designed to explore the role of three penicillin-binding proteins (PBPs) in mediating the induction effect of cefotaxime. Three deletion mutants of the genes mrcA, mrcB, and ftsI, encoding the proteins PBP1a, PBP1b, and PBP3, respectively, were constructed using the parental Salmonella strain SH16SP46. Gram staining and scanning electron microscopy showed that these mutants showed normal morphology comparable to the parental strain without cefotaxime treatment. However, under the stress of 1/8 MIC of cefotaxime, the strains WT, ΔmrcA, and ΔftsI, rather than ΔmrcB, exhibited filamentous morphological change. Moreover, cefotaxime treatment significantly enhanced biofilm formation by the strains WT, ΔmrcA, and ΔftsI, but not by the ΔmrcB strain. The complement of mrcB gene in the ΔmrcB strain recovered the enhanced biofilm formation and filamentous morphological change induced by cefotaxime. Our results suggest that PBP1b encoded by mrcB gene may be a binding target of cefotaxime for initiating the effect on Salmonella morphology and biofilm formation. The study will contribute to further understanding of the regulatory mechanism of cefotaxime on Salmonella biofilm formation.}, }
@article {pmid36948321, year = {2023}, author = {Cheng, L and Yang, W and Liang, H and Nabi, M and Li, Y and Wang, H and Hu, J and Chen, T and Gao, D}, title = {Nitrogen removal from mature landfill leachate through enhanced Partial Nitrification-Anammox process in an innovative multi-stage fixed biofilm reactor.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {162959}, doi = {10.1016/j.scitotenv.2023.162959}, pmid = {36948321}, issn = {1879-1026}, abstract = {In the current integrated PN/A method/process for mature landfill leachate treatment, microbial inhibition and low nitrogen removal capacity are the big barriers due to high ammonia concentration and low C/N. This study aimed to evaluate the performance of a high-rate nitrogen removal lab-scale reactor, which combines pre-denitrification and Partial Nitrification-Anammox (PN/A) in a multi-stage fixed biofilm reactor (MFBR), for mature landfill leachate treatment. A nitrogen removal efficiency (NRE) of 90.43 % and an average nitrogen removal rate (NRR) of 0.94 kg/m[3]·d were observed at an influent NH+ 4-N concentration of 2274.39 mg/L during the last operational phase. The nitrogen mass balance showed that the nitrogen concentration gradually decreases along the course, and nitrogen was mainly removed in the aerobic chambers, in which Anammox contributed to 86.4 % of the removed nitrogen, while the front anoxic chamber is mainly used to remove NO- 3-N from the recirculation. Redundancy analysis showed that the variation in NH+ 4-N concentration along the course was the main factor affecting microbial community succession, which shows that the reactor configuration enables efficient cooperation and distribution of different microorganisms. Moreover, economic analysis of MFBR process showed that the energy consumption and carbon addition were reduced by 58.9 % and 100 %, respectively. Therefore, the MFBR established in this study, with its new configuration, achieves efficient treatment of landfill leachate in a single reactor and is environmentally friendly, and could be considered as a reference for full-scale landfill leachate treatment.}, }
@article {pmid36947926, year = {2023}, author = {Wu, M and Lai, CY and Wang, Y and Yuan, Z and Guo, J}, title = {Microbial nitrate reduction in propane- or butane-based membrane biofilm reactors under oxygen-limiting conditions.}, journal = {Water research}, volume = {235}, number = {}, pages = {119887}, doi = {10.1016/j.watres.2023.119887}, pmid = {36947926}, issn = {1879-2448}, abstract = {Nitrate contamination has been commonly detected in water environments and poses serious hazards to human health. Previously methane was proposed as a promising electron donor to remove nitrate from contaminated water. Compared with pure methane, natural gas, which not only contains methane but also other short chain gaseous alkanes (SCGAs), is less expensive and more widely available, representing a more attractive electron source for removing oxidized contaminants. However, it remains unknown if these SCGAs can be utilized as electron donors for nitrate reduction. Here, two lab-scale membrane biofilm reactors (MBfRs) separately supplied with propane and butane were operated under oxygen-limiting conditions to test its feasibility of microbial nitrate reduction. Long-term performance suggested nitrate could be continuously removed at a rate of ∼40-50 mg N/L/d using propane/butane as electron donors. In the absence of propane/butane, nitrate removal rates significantly decreased both in the long-term operation (∼2-10 and ∼4-9 mg N/L/d for propane- and butane-based MBfRs, respectively) and batch tests, indicating nitrate bio-reduction was driven by propane/butane. The consumption rates of nitrate and propane/butane dramatically decreased under anaerobic conditions, but recovered after resupplying limited oxygen, suggesting oxygen was an essential triggering factor for propane/butane-based nitrate reduction. High-throughput sequencing targeting 16S rRNA, bmoX and narG genes indicated Mycobacterium/Rhodococcus/Thauera were the potential microorganisms oxidizing propane/butane, while various denitrifiers (e.g. Dechloromonas, Denitratisoma, Zoogloea, Acidovorax, Variovorax, Pseudogulbenkiania and Rhodanobacter) might perform nitrate reduction in the biofilms. Our findings provide evidence to link SCGA oxidation with nitrate reduction under oxygen-limiting conditions and may ultimately facilitate the design of cost-effective techniques for ex-situ groundwater remediation using natural gas.}, }
@article {pmid36947565, year = {2023}, author = {Trindade, SC and Lopes, MPP and Oliveira, TTMC and Silva, MJ and Queiroz, GA and Jesus, TS and Santos, EKN and Carvalho-Filho, PC and Falcão, MML and Miranda, PM and Santos, RPB and Figueiredo, CA and Cruz, &#xc1;A and Seymour, GJ and Gomes-Filho, IS}, title = {Single nucleotide variants in the IL33 and IL1RL1 (ST2) genes are associated with periodontitis and with Aggregatibacter actinomycetemcomitans in the dental plaque biofilm: A putative role in understanding the host immune response in periodontitis.}, journal = {PloS one}, volume = {18}, number = {3}, pages = {e0283179}, pmid = {36947565}, issn = {1932-6203}, mesh = {Humans ; Aggregatibacter actinomycetemcomitans/genetics ; Biofilms ; Cross-Sectional Studies ; *Dental Plaque/genetics ; Immunity ; *Interleukin-1 Receptor-Like 1 Protein/genetics ; *Interleukin-33/genetics ; Nucleotides ; *Periodontitis/genetics ; Polymorphism, Single Nucleotide ; }, abstract = {The Interleukin (IL)-33 is important in several inflammatory diseases and its cellular receptor is the Interleukin 1 receptor-like 1 (IL1RL1), also called suppression of tumorigenicity 2 ligand (ST2L). This study investigated associations between single nucleotide variants (SNVs) in the IL33 gene and in the IL1RL1 (ST2) gene with periodontitis. Additionally, aimed to determine the role of Aggregatibacter actinomycetemcomitans (Aa) relative amount in the subgingival biofilm in these associations. A cross-sectional study was carried out with 506 individuals that answered a structured questionnaire used to collect their health status, socioeconomic-demographic, and behavioral characteristics. Periodontal examination was performed to determine the presence and severity of periodontitis, and subgingival biofilm samples were collected to quantify the relative amount of Aa by real time polymerase chain reaction. Human genomic DNA was extracted from whole blood cells and SNV genotyping was performed. Logistic regression estimated the association measurements, odds ratio (OR), and 95% confidence interval (95%CI), between the IL33 and ST2 genes with periodontitis, and subgroup analyses assessed the relative amount of Aa in these associations. 23% of individuals had periodontitis. Adjusted measurements showed a statistically significant inverse association between two SNVs of the ST2; rs148548829 (C allele) and rs10206753 (G allele). These two alleles together with a third SNV, the rs11693204 (A allele), were inversely associated with moderate periodontitis. One SNV of the IL33 gene also showed a statistically significant inverse association with moderate periodontitis. Nine SNVs of the ST2 gene were inversely associated with the relative amount of Aa. In the high Aa subgroup, there was a direct association between 11 SNVs of the ST2 gene and moderate periodontitis and two SNVs of the ST2 gene and severe periodontitis, and eight SNVs of the ST2 gene and periodontitis. These exploratory findings of genetic variants in IL-33/ST2 axis support the concept that the different tissue responses among individuals with periodontitis may be modulated by the host's genetics, influencing the physiopathology of the disease.}, }
@article {pmid36946779, year = {2023}, author = {Johnston, EL and Zavan, L and Bitto, NJ and Petrovski, S and Hill, AF and Kaparakis-Liaskos, M}, title = {Planktonic and Biofilm-Derived Pseudomonas aeruginosa Outer Membrane Vesicles Facilitate Horizontal Gene Transfer of Plasmid DNA.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0517922}, doi = {10.1128/spectrum.05179-22}, pmid = {36946779}, issn = {2165-0497}, abstract = {Outer membrane vesicles (OMVs) produced by Gram-negative bacteria package various cargo, including DNA that can be transferred to other bacteria or to host cells. OMV-associated DNA has been implicated in mediating horizontal gene transfer (HGT) between bacteria, which includes the dissemination of antibiotic resistance genes within and between bacterial species. Despite the known ability of OMVs to mediate HGT, the mechanisms of DNA packaging into OMVs remain poorly characterized, as does the effect of bacterial growth conditions on the DNA cargo composition of OMVs and their subsequent abilities to mediate HGT. In this study, we examined the DNA content of OMVs produced by the opportunistic pathogen Pseudomonas aeruginosa grown in either planktonic or biofilm conditions. Analysis of planktonic growth-derived OMVs revealed their ability to package and protect plasmid DNA from DNase degradation and to transfer plasmid-encoded antibiotic resistance genes to recipient, antibiotic-sensitive P. aeruginosa bacteria at a greater efficiency than transformation with plasmid alone. Comparisons of planktonic and biofilm-derived P. aeruginosa OMVs demonstrated that biofilm-derived OMVs were smaller but were associated with more plasmid DNA than planktonic-derived OMVs. Additionally, biofilm-derived P. aeruginosa OMVs were more efficient in the transformation of competent P. aeruginosa bacteria, compared to transformations with an equivalent number of planktonic-derived OMVs. The findings of this study highlight the importance of bacterial growth conditions for the packaging of DNA within P. aeruginosa OMVs and their ability to facilitate HGT, thus contributing to the spread of antibiotic resistance genes between P. aeruginosa bacteria. IMPORTANCE Bacterial membrane vesicles (BMVs) mediate interbacterial communication, and their ability to package DNA specifically contributes to biofilm formation, antibiotic resistance, and HGT between bacteria. However, the ability of P. aeruginosa OMVs to mediate HGT has not yet been demonstrated. Here, we reveal that P. aeruginosa planktonic and biofilm-derived OMVs can deliver plasmid-encoded antibiotic resistance to recipient P. aeruginosa. Additionally, we demonstrated that P. aeruginosa biofilm-derived OMVs were associated with more plasmid DNA compared to planktonic-derived OMVs and were more efficient in the transfer of plasmid DNA to recipient bacteria. Overall, this demonstrated the ability of P. aeruginosa OMVs to facilitate the dissemination of antibiotic resistance genes, thereby enabling the survival of susceptible bacteria during antibiotic treatment. Investigating the roles of biofilm-derived BMVs may contribute to furthering our understanding of the role of BMVs in HGT and the spread of antibiotic resistance in the environment.}, }
@article {pmid36946276, year = {2023}, author = {Sójka, O and Keskin, D and van der Mei, HC and van Rijn, P and Gagliano, MC}, title = {Nanogel-based coating as an alternative strategy for biofilm control in drinking water distribution systems.}, journal = {Biofouling}, volume = {}, number = {}, pages = {1-14}, doi = {10.1080/08927014.2023.2190023}, pmid = {36946276}, issn = {1029-2454}, abstract = {Biofilm formation and detachment in drinking water distribution systems (DWDS) can lead to several operational issues. Here, an alternative biofilm control strategy of limiting bacterial adhesion by application of a poly(N-isopropylmethacrylamide)-based nanogel coating on DWDS pipe walls was investigated. The nanogel coatings were successfully deposited on surfaces of four polymeric pipe materials commonly applied in DWDS construction. Nanogel-coated and non-coated pipe materials were characterized in terms of their surface hydrophilicity and roughness. Four DWDS relevant bacterial strains, representing Sphingomonas and Pseudomonas, were used to evaluate the anti-adhesive performance of the coating in 4 h adhesion and 24 h biofilm assays. The presence of the nanogel coating resulted in adhesion reduction up to 97%, and biofilm reduction up to 98%, compared to non-coated surfaces. These promising results motivate further investigation of nanogel coatings as a strategy for biofilm prevention in DWDS.}, }
@article {pmid36946046, year = {2023}, author = {Zhang, Z and Liao, H and Yang, M and Hu, C and DU, Y}, title = {[Levofloxacin combined with cellulase can eradicate bacille Calmette-Guerin biofilm infection].}, journal = {Nan fang yi ke da xue xue bao = Journal of Southern Medical University}, volume = {43}, number = {2}, pages = {257-264}, doi = {10.12122/j.issn.1673-4254.2023.02.14}, pmid = {36946046}, issn = {1673-4254}, abstract = {OBJECTIVE: To investigate the inhibitory effects of levofloxacin (LEV) combined with cellulase against bacille CalmetteGuerin (BCG) biofilms in vitro.<br><br>METHODS: The mature growth cycle of BCG biofilms was determined using the XTT method and crystal violet staining. BCG planktonic bacteria and BCG biofilms were treated with different concentrations of LEV and cellulose alone or jointly, and the changes in biofilm biomass were quantified with crystal violet staining. The mature BCG biofilm was then treated with cellulase alone for 24 h, and after staining with SYTO 9 and Calcofluor White Stain, the number of viable bacteria and the change in cellulose content in the biofilm were observed with confocal laser scanning microscopy. The structural changes of the treated biofilm were observed under scanning electron microscopy.<br><br>RESULTS: The MIC, MBC and MBEC values of LEV determined by broth microdilution method were 4 &#x3bc;g/mL, 8 &#x3bc;g/mL and 1024 &#x3bc;g/mL, respectively. The combined treatment with 1/4&#xd7;MIC LEV and 2.56, 5.12 or 10.24 U/mL cellulase resulted in a significant reduction in biofilm biomass (P < 0.001). Cellulase treatments at the concentrations of 10.24, 5.12 and 2.56 U/mL all produced significant dispersion effects on mature BCG biofilms (P < 0.001).<br><br>CONCLUSION: LEV combined with cellulose can effectively eradicate BCG biofilm infections, suggesting the potential of glycoside hydrolase therapy for improving the efficacy of antibiotics against biofilmassociated infections caused by Mycobacterium tuberculosis.}, }
@article {pmid36944677, year = {2023}, author = {Brothers, KM and Parker, DM and Taguchi, M and Ma, D and Mandell, JB and Thurlow, LL and Byrapogu, VC and Urish, KL}, title = {Dose optimization in surgical prophylaxis: sub-inhibitory dosing of vancomycin increases rates of biofilm formation and the rates of surgical site infection.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {4593}, pmid = {36944677}, issn = {2045-2322}, support = {NIAMS K08AR071494/AR/NIAMS NIH HHS/United States ; NCATS KL2TR0001856/TR/NCATS NIH HHS/United States ; }, abstract = {Antibiotic stewardship is viewed as having great public health benefit with limited direct benefit to the patient at the time of administration. The objective of our study was to determine if inappropriate administration of antibiotics could create conditions that would increase the rates of surgical infection. We hypothesized that sub-MIC levels of vancomycin would increase Staphylococcus aureus growth, biofilm formation, and rates of infection. S. aureus MRSA and MSSA strains were used for all experiments. Bacteria were grown planktonically and monitored using spectrophotometry. Quantitative agar culture was used to measure planktonic and biofilm bacterial burden. A mouse abscess model was used to confirm phenotypes in vivo. In the planktonic growth assay, increases in bacterial burden at ¼ MIC vancomycin were observed in USA300 JE2 by 72 h. Similar findings were observed with ½ MIC in Newman and SH1000. For biofilm formation, USA300 JE2 at ¼ and ½ MIC vancomycin increased biofilm formation by approximately 1.3- and 2.3-fold respectively at 72 h as compared to untreated controls. Similar findings were observed with Newman and SH1000 with a 2.4-fold increase in biofilm formation at ½ MIC vancomycin. In a mouse abscess model, there was a 1.2-fold increase with sub-MIC vancomycin at 3 days post infection. Our study showed that Sub-optimal vancomycin dosing promoted S. aureus planktonic growth and biofilm formation, phenotypic measures of bacterial virulence. This phenotype induced by sub-MIC levels of vancomycin was also observed to increase rates of infection and pathogenesis in our mouse model. Risks of exposure to sub-MIC concentrations with vancomycin in surgical procedures are greater as there is decreased bioavailability in tissue in comparison to other antibiotics. This highlights the importance of proper antibiotic selection, stewardship, and dosing for both surgical prophylaxis and treatment of infection.}, }
@article {pmid36944321, year = {2023}, author = {Kognou, ALM and Chio, C and Khatiwada, JR and Shrestha, S and Chen, X and Zhu, Y and Ngono Ngane, RA and Agbor Agbor, G and Jiang, ZH and Xu, CC and Qin, W}, title = {Characterization of Potential Virulence, Resistance to Antibiotics and Heavy Metals, and Biofilm-forming Capabilities of Soil Lignocellulolytic Bacteria.}, journal = {Microbial physiology}, volume = {}, number = {}, pages = {}, doi = {10.1159/000530228}, pmid = {36944321}, issn = {2673-1673}, abstract = {Soil bacteria participate in self-immobilization processes for survival, persistence and producing virulence factors in some niches or hosts through their capacities of autoaggregation, cell surface hydrophobicity, biofilm formation, and antibiotic and heavy metal resistance. This study investigated potential virulence, antibiotics and heavy metals resistance, solvent adhesion, and biofilm-forming capabilities of six cellulolytic bacteria isolated from soil samples: Paenarthrobacter sp. MKAL1, Hymenobacter sp. MKAL2, Mycobacterium sp. MKAL3, Stenotrophomonas sp. MKAL4, Chryseobacterium sp. MKAL5 and Bacillus sp. MKAL6. Strains were subjected to phenotypic methods, including heavy metal and antibiotic susceptibility and virulence factors (protease, lipase, capsule production, autoaggregation, hydrophobicity and biofilm formation). The effect of ciprofloxacin was also investigated on bacterial susceptibility over time, cell membrane and biofilm formation. Strains MKAL2, MKAL5 and MKAL6 exhibited protease and lipase activities, while only MKAL6 produced capsules. All strains were capable of aggregating, forming biofilm and adhering to solvents. Strains tolerated high amounts of chromium, lead, zinc, nickel and manganese and were resistant to lincomycin. Ciprofloxacin exhibited bactericidal activity against these strains. Although the phenotypic evaluation of virulence factors of bacteria can indicate their pathogenic nature, an in-depth genetic study of virulence, antibiotic and heavy metal resistance genes is required.}, }
@article {pmid36942961, year = {2023}, author = {Archambault, L and Koshy-Chenthittayil, S and Thompson, A and Dongari-Bagtzoglou, A and Laubenbacher, R and Mendes, P}, title = {Corrected and Republished from: "Understanding Lactobacillus paracasei and Streptococcus oralis Biofilm Interactions through Agent-Based Modeling".}, journal = {mSphere}, volume = {}, number = {}, pages = {e0065622}, doi = {10.1128/msphere.00656-22}, pmid = {36942961}, issn = {2379-5042}, abstract = {As common commensals residing on mucosal tissues, Lactobacillus species are known to promote health, while some Streptococcus species act to enhance the pathogenicity of other organisms in those environments. In this study we used a combination of in vitro imaging of live biofilms and computational modeling to explore biofilm interactions between Streptococcus oralis, an accessory pathogen in oral candidiasis, and Lactobacillus paracasei, an organism with known probiotic properties. A computational agent-based model was created where the two species interact only by competing for space, oxygen, and glucose. Quantification of bacterial growth in live biofilms indicated that S. oralis biomass and cell numbers were much lower than predicted by the model. Two subsequent models were then created to examine more complex interactions between these species, one where L. paracasei secretes a surfactant and another where L. paracasei secretes an inhibitor of S. oralis growth. We observed that the growth of S. oralis could be affected by both mechanisms. Further biofilm experiments support the hypothesis that L. paracasei may secrete an inhibitor of S. oralis growth, although they do not exclude that a surfactant could also be involved. This contribution shows how agent-based modeling and experiments can be used in synergy to address multiple-species biofilm interactions, with important roles in mucosal health and disease. IMPORTANCE We previously discovered a role of the oral commensal Streptococcus oralis as an accessory pathogen. S. oralis increases the virulence of Candida albicans infections in murine oral candidiasis and epithelial cell models through mechanisms which promote the formation of tissue-damaging biofilms. Lactobacillus species have known inhibitory effects on biofilm formation of many microbes, including Streptococcus species. Agent-based modeling has great advantages as a means of exploring multifaceted relationships between organisms in complex environments such as biofilms. Here, we used an iterative collaborative process between experimentation and modeling to reveal aspects of the mostly unexplored relationship between S. oralis and L. paracasei in biofilm growth. The inhibitory nature of L. paracasei on S. oralis in biofilms may be exploited as a means of preventing or alleviating mucosal fungal infections.}, }
@article {pmid36942960, year = {2023}, author = {Archambault, L and Koshy-Chenthittayil, S and Thompson, A and Dongari-Bagtzoglou, A and Laubenbacher, R and Mendes, P}, title = {Correction for Archambault et al., "Understanding Lactobacillus paracasei and Streptococcus oralis Biofilm Interactions through Agent-Based Modeling".}, journal = {mSphere}, volume = {}, number = {}, pages = {e0064822}, doi = {10.1128/msphere.00648-22}, pmid = {36942960}, issn = {2379-5042}, }
@article {pmid36942200, year = {2023}, author = {Alharbi, MS and Alshehri, FA and Alobaidi, AS and Alrowis, R and Alshibani, N and Niazy, AA}, title = {High molecular weight hyaluronic acid reduces the growth and biofilm formation of the oral pathogen Porphyromonas gingivalis.}, journal = {The Saudi dental journal}, volume = {35}, number = {2}, pages = {141-146}, pmid = {36942200}, issn = {1013-9052}, abstract = {BACKGROUND: Porphyromonas gingivalis (P. gingivalis) is viewed as a keystone microorganism in the pathogenesis of periodontal and peri-implant diseases. Hyaluronic acid (HA) is believed to exert antimicrobial activity. The aim of this study is to assess the in-vitro growth and biofilm formation of P. gingivalis under HA and compare the effect of HA to that of azithromycin (AZM) and chlorhexidine (CHX).<br><br>MATERIALS AND METHODS: In each material, the minimum inhibitory concentration (MIC), 50% MIC, 25% MIC, and 12.5% MIC were tested. The growth of P. gingivalis was evaluated by absorbance spectrophotometry after 48&#xa0;h. A biofilm inhibition assay was performed on a 72-hour culture by washing planktonic bacterial cells, fixing and staining adherent cells, and measuring the variation in stain concentrations relative to the untreated control using absorbance spectrophotometry.<br><br>RESULTS: The results show that the overall growth of P. gingivalis after 48&#xa0;h was 0.048&#xa0;&#xb1;&#xa0;0.030, 0.008&#xa0;&#xb1;&#xa0;0.013, and 0.073&#xa0;&#xb1;&#xa0;0.071 under HA, AZM, and CHX, respectively, while the untreated control reached 0.236&#xa0;&#xb1;&#xa0;0.039. HA was also able to significantly reduce the biofilm formation of P. gingivalis by 64.30&#xa0;% &#xb1; 22.39, while AZM and CHX reduced biofilm formation by 91.16&#xa0;%&#xb1;12.58 and 88.35&#xa0;%&#xb1;17.11, respectively.<br><br>CONCLUSIONS: High molecular-weight HA significantly inhibited the growth of P. gingivalis. The overall effect of HA on the growth of P. gingivalis was similar to that of CHX but less than that of AZM. HA was also able to significantly reduce the biofilm formation of P. gingivalis. However, the ability of HA to prevent the biofilm formation of P. gingivalis was generally less than that of both AZM and CHX.}, }
@article {pmid36938129, year = {2022}, author = {Mohanta, YK and Chakrabartty, I and Mishra, AK and Chopra, H and Mahanta, S and Avula, SK and Patowary, K and Ahmed, R and Mishra, B and Mohanta, TK and Saravanan, M and Sharma, N}, title = {Nanotechnology in combating biofilm: A smart and promising therapeutic strategy.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1028086}, pmid = {36938129}, issn = {1664-302X}, abstract = {Since the birth of civilization, people have recognized that infectious microbes cause serious and often fatal diseases in humans. One of the most dangerous characteristics of microorganisms is their propensity to form biofilms. It is linked to the development of long-lasting infections and more severe illness. An obstacle to eliminating such intricate structures is their resistance to the drugs now utilized in clinical practice (biofilms). Finding new compounds with anti-biofilm effect is, thus, essential. Infections caused by bacterial biofilms are something that nanotechnology has lately shown promise in treating. More and more studies are being conducted to determine whether nanoparticles (NPs) are useful in the fight against bacterial infections. While there have been a small number of clinical trials, there have been several in vitro outcomes examining the effects of antimicrobial NPs. Nanotechnology provides secure delivery platforms for targeted treatments to combat the wide range of microbial infections caused by biofilms. The increase in pharmaceuticals' bioactive potential is one of the many ways in which nanotechnology has been applied to drug delivery. The current research details the utilization of several nanoparticles in the targeted medication delivery strategy for managing microbial biofilms, including metal and metal oxide nanoparticles, liposomes, micro-, and nanoemulsions, solid lipid nanoparticles, and polymeric nanoparticles. Our understanding of how these nanosystems aid in the fight against biofilms has been expanded through their use.}, }
@article {pmid36937307, year = {2023}, author = {Zhu, X and Dou, F and Long, M and Wang, X and Liu, W and Li, F and Liu, T and Wu, Y}, title = {Electron shuttle-dependent biofilm formation and biocurrent generation: Concentration effects and mechanistic insights.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1070800}, pmid = {36937307}, issn = {1664-302X}, abstract = {INTRODUCTION: Electron shuttles (ESs) play a key role in extracellular electron transfer (EET) in Shewanella oneidensis MR-1. However, the quantification relationship between ES concentration, biofilm formation, and biocurrent generation has not been clarified.<br><br>METHODS: In this study, 9,10-anthraquinone-2-sulfonic acid (AQS)-mediated EET and biofilm formation were evaluated at different AQS concentrations in bioelectrochemical systems (BESs) with S. oneidensis MR-1.<br><br>RESULTS AND DISCUSSION: Both the biofilm biomass (9- to 17-fold) and biocurrent (21- to 80-fold) were substantially enhanced by exogenous AQS, suggesting the dual ability of AQS to promote both biofilm formation and electron shuttling. Nevertheless, biofilms barely grew without the addition of exogenous AQS, revealing that biofilm formation by S. oneidensis MR-1 is highly dependent on electron shuttling. The biofilm growth was delayed in a BES of 2,000 &#x3bc;M AQS, which is probably because the redundant AQS in the bulk solution acted as a soluble electron acceptor and delayed biofilm formation. In addition, the maximum biocurrent density in BESs with different concentrations of AQS was fitted to the Michaelis-Menten equation (R [2] = 0.97), demonstrating that microbial-catalyzed ES bio-reduction is the key limiting factor of the maximum biocurrent density in BESs. This study provided a fundamental understanding of ES-mediated EET, which could be beneficial for the enrichment of electroactive biofilms, the rapid start-up of microbial fuel cells (MFCs), and the design of BESs for wastewater treatment.}, }
@article {pmid36937277, year = {2023}, author = {Xie, J and Zhang, H and Li, Y and Li, H and Pan, Y and Zhao, Y and Xie, Q}, title = {Transcriptome analysis of the biofilm formation mechanism of Vibrio parahaemolyticus under the sub-inhibitory concentrations of copper and carbenicillin.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1128166}, pmid = {36937277}, issn = {1664-302X}, abstract = {Biofilm formation of Vibrio parahaemolyticus enhanced its tolerance to the environment, but caused many serious problems to food safety and human health. In this paper, the effects of copper and carbenicillin (CARB) stress on the formation of the biofilms of V. parahaemolyticus organisms were studied, and RNA sequencing technology was used to compare the differences in transcriptome profiles of the biofilm-related genes of V. parahaemolyticus organisms under different sub-inhibitory stresses. The results proved that V. parahaemolyticus had a large growth difference under the two stresses, copper and CARB at 1/2 minimal inhibitory concentration (MIC), and it could form a stable biofilm under both stress conditions. The amount of biofilm formed under CARB stress was significantly higher than that of copper stress (p < 0.05). Based on the analysis of transcriptome sequencing results 323, 1,550, and 1,296 significantly differential expressed genes were identified in the three treatment groups namely 1/2 MIC CARB, Cu[2+], and Cu[2+]+CARB. Through COG annotation, KEGG metabolic pathway analysis and gene expression analysis related to biofilm formation, the functional pathways of transcriptome changes affecting V. parahaemolyticus were different in the three treatment groups, and the CARB treatment group was significantly different from the other two groups. These differences indicated that the ABC transport system, two-component system and quorum sensing were all involved in the biofilm formation of the V. parahaemolytic by regulating flagellar motility, extracellular polysaccharides and extracellular polymer synthesis. Exploring the effects of different stress conditions on the transcriptome of V. parahaemolyticus could provide a basis for future research on the complex network system that regulates the formation of bacterial biofilms.}, }
@article {pmid36936302, year = {2023}, author = {Mao, T and Chai, B and Xiong, Y and Wang, H and Nie, L and Peng, R and Li, P and Yu, Z and Fang, F and Gong, X}, title = {In Vitro Inhibition of Growth, Biofilm Formation, and Persisters of Staphylococcus aureus by Pinaverium Bromide.}, journal = {ACS omega}, volume = {8}, number = {10}, pages = {9652-9661}, pmid = {36936302}, issn = {2470-1343}, abstract = {Biofilm or persister cells formed by Staphylococcus aureus are closely related to pathogenicity. However, no antimicrobials exist to inhibit biofilm formation or persister cells induced by S. aureus in clinical practice. This study found that pinaverium bromide had antibacterial activity against S. aureus, with the MIC50/MIC90 at 12.5/25 μM, respectively. Pinaverium bromide (at 4 × MIC) showed a rapid bactericidal effect on S. aureus planktonic cells, and it was more effective (at least 1-log10 cfu/mL) than linezolid, vancomycin, and ampicillin at 4 h of the time-killing test. Pinaverium bromide (at 10 × MIC) significantly inhibited the formation of S. aureus persister cells (at least 3-log10 cfu/mL) than linezolid, vancomycin, and ampicillin at 24, 48, 72, 96, and 120 h of the time-killing test. Biofilm formation and adherent cells of S. aureus isolates were significantly inhibited by pinaverium bromide (at 1/2 or 1/4 × MICs). The fluorescence intensity of the membrane polarity of S. aureus increased with the treatment of pinaverium bromide (≥1 × MIC), and the MICs of pinaverium bromide increased by 4 times with the addition of cell membrane phospholipids, phosphatidyl glycerol and cardiolipin. The cell viabilities of human hepatocellular carcinoma cells HepG2 and Huh7, mouse monocyte-macrophage cells J774, and human hepatic stellate cells LX-2 were slightly inhibited by pinaverium bromide (<50 μM). There were 54 different abundance proteins detected in the pinaverium bromide-treated S. aureus isolate by proteomics analysis, of which 33 proteins increased, whereas 21 proteins decreased. The abundance of superoxide dismutase sodM and ica locus proteins icaA and icaB decreased. While the abundance of global transcriptional regulator spxA and Gamma-hemolysin component B increased. In conclusion, pinaverium bromide had an antibacterial effect on S. aureus and significantly inhibited the formation of biofilm and persister cells of S. aureus.}, }
@article {pmid36935141, year = {2023}, author = {Arismendi, D and Vera, I and Ahumada, I and Richter, P}, title = {A thin biofilm of chitosan as a sorptive phase in the rotating disk sorptive extraction of triclosan and methyl triclosan from water samples.}, journal = {Analytica chimica acta}, volume = {1252}, number = {}, pages = {341053}, doi = {10.1016/j.aca.2023.341053}, pmid = {36935141}, issn = {1873-4324}, mesh = {Animals ; *Triclosan/analysis ; *Chitosan ; Water ; *Water Pollutants, Chemical/analysis ; }, abstract = {The features and nature of the sorptive phase may be the stage that determines the scope of microextraction techniques. In search of new alternatives, materials of natural origin have recently been explored to establish greener analytical strategies. Based on that search, this research proposes the use of chitosan as a sorptive phase, which was assessed in the rotating disk sorptive extraction of emerging contaminants from aqueous systems. Chitosan is a biopolymer of animal origin that is usually found in the shells of crustaceans. The main characteristic of this material is the presence of a high number of nitrogenous groups, which gives it high reactivity, but its main disadvantage is associated with its high swelling capacity. In this research, chitosan was crosslinked with a low concentration of glutaraldehyde to form thin films that were easily immobilized on the surface of the rotating disk. The main advantage of this modification is the considerable decrease in the swelling capacity, which prevents loss and rupture of the sorbent during high rotation of the disk. In addition, it not only improved the physical characteristics of chitosan but also increased its extraction capacity. With regard to its use as a sorptive phase, all the variables associated with the microextraction of the analytes were studied, and optimal variables were found to be: pH 4, 20% NaCl (salting out effect), 30-45 min as equilibrium time and elution of analytes with a mixture of methanol:ethyl acetate (1:1). Validation of the methodology for the determination of methyl triclosan and triclosan was carried out, and relative recoveries between 89 and 96% and relative standard deviations less than 14% were found. The detection limits were 0.11 and 0.20 μg L[-1], respectively. Through its application in real samples (natural and residual waters), triclosan was quantified between 0.7 and 1.3 μg L[-1]. Finally, the "green" properties of the phase were evaluated, demonstrating that it is reusable for at least three cycles and biodegradable. Compared to its efficiency with a commercial phase (in this case, the styrene divinyl benzene phase), the proposed biosorbent provided a similar and even higher sorptive capacity (depending on the analyte).}, }
@article {pmid36934281, year = {2023}, author = {Bayani, M and Raisolvaezin, K and Almasi-Hashiani, A and Mirhoseini, SH}, title = {Bacterial biofilm prevalence in dental unit waterlines: a systematic review and meta-analysis.}, journal = {BMC oral health}, volume = {23}, number = {1}, pages = {158}, pmid = {36934281}, issn = {1472-6831}, abstract = {BACKGROUNDS: Numerous studies have shown that dental unit water lines (DUWLs) are often contaminated by a wide range of micro-organisms (bacteria, fungi, protozoa) and various prevalence have been reported for it in previous studies. Therefore, this review study aims to describe the prevalence of bacterial biofilm contamination of DUWLs.<br><br>METHODS: This is a systematic review and meta-analysis in which the related keywords in different international databases, including Medline (via PubMed) and Scopus were searched. The retrieved studies were screened and the required data were extracted from the included studies. Three standard methods including American Dental Association (ADA), The Center for Disease Control and Prevention (CDC) and contaminated&#x2009;>&#x2009;100&#xa0;CFU/ml(C-100) standards were used to assess the bacterial biofilm contamination of DUWLs. All studies that calculated the prevalence of bacterial biofilm contamination of DUWLs, and English full-text studies were included in the meta-analysis. Studies that did not have relevant data or used unusual laboratory methods were excluded. Methodological risk of bias was assessed by a related checklist and finally, the data were pooled by fixed or random-effect models.<br><br>RESULTS: Seven hundred and thirty-six studies were identified and screened and 26 related studies were included in the meta-analysis. The oldest included study was published in 1976 and the most recent study was published in 2020. According to the ADA, CDC and C-100 standards, the prevalence of bacterial contamination was estimated to be 85.0% (95% confidence interval (CI): 66.0-94.0%), 77.0% (95%CI: 66.0-85.0%) and 69.0% (95%CI: 67.0-71.0%), respectively. The prevalence of Legionella Pneumophila and Pseudomonas Aeruginosa in DUWLs was estimated to be 12.0% (95%CI: 10.0-14.0%) and 8.0% (95%CI: 2.0-24.0%), respectively.<br><br>CONCLUSION: The results of this review study suggested a high prevalence of bacterial biofilm in DUWLs; therefore, the use of appropriate disinfecting protocol is recommended to reduce the prevalence of contamination and reduce the probable cross-infection.}, }
@article {pmid36933573, year = {2023}, author = {Yang, J and Sim, YB and Moon Kim, S and Joo, HH and Jung, JH and Kim, SH}, title = {Enhanced Continuous Biohydrogen Production using Dynamic Membrane with Conductive Biofilm Supporter.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {128900}, doi = {10.1016/j.biortech.2023.128900}, pmid = {36933573}, issn = {1873-2976}, abstract = {The present study investigated the effect of a conductive biofilm supporter on continuous production of biohydrogen in a dynamic membrane bioreactor (DMBR). Two lab-scale DMBRs were operated: one with a nonconductive polyester mesh (DMBR I) and the other with a conductive stainless-steel mesh (DMBR II). The highest average hydrogen productivity and the yield were 16.8% greater in DMBR II than in DMBR I, with values of 51.64 ± 0.66 L/L-d and 2.01 ± 0.03 mol H2/mol hexoseconsumed, respectively. The improved hydrogen production was concurrent with a higher NADH/NAD[+] ratio and a lower ORP (Oxidation-reduction potential). Metabolic flux analysis implied that the conductive supporter promoted H2-producing acetogenesis and repressed competitive NADH-consuming pathways, such as homoacetogenesis and lactate production. Microbial community analysis revealed that electroactive Clostridium sp. were the dominant H2 producers in DMBR II. Conclusively, conductive meshes may be useful as biofilm supporters of dynamic membranes during H2 production for selectively enhancing H2-producing pathways.}, }
@article {pmid36933360, year = {2023}, author = {Wu, J and McAuliffe, O and O'Byrne, CP}, title = {Trehalose transport occurs via TreB in Listeria monocytogenes and it influences biofilm development and acid resistance.}, journal = {International journal of food microbiology}, volume = {394}, number = {}, pages = {110165}, doi = {10.1016/j.ijfoodmicro.2023.110165}, pmid = {36933360}, issn = {1879-3460}, abstract = {Listeria monocytogenes is a pathogenic bacterium that can inhabit a diverse range of environmental niches. This is largely attributed to the high proportion of carbohydrate-specific phosphotransferase system (PTS) genes in its genome. Carbohydrates can be assimilated as sources of energy but additionally they can serve as niche-specific cues for L. monocytogenes to shape its global gene expression, in order to cope with anticipated stresses. To examine carbon source utilization among wild L. monocytogenes isolates and to understand underlying molecular mechanisms, a diverse collection of L. monocytogenes strains (n = 168) with whole genome sequence (WGS) data available was screened for the ability to grow in chemically defined media with different carbon sources. The majority of the strains grew in glucose, mannose, fructose, cellobiose, glycerol, trehalose, and sucrose. Maltose, lactose, and rhamnose supported slower growth while ribose did not support any growth. In contrast to other strains, strain1386, which belonged to clonal complex 5 (CC5), was unable to grow on trehalose as a sole carbon source. WGS data revealed that it carried a substitution (N352K) in a putative PTS EIIBC trehalose transporter, TreB, while this asparagine residue is conserved in other strains in this collection. Spontaneous mutants of strain 1386 that could grow in trehalose were found to harbour a reversion of the substitution in TreB. These results provide genetic evidence that TreB is responsible for trehalose uptake and that the N352 residue is essential for TreB activity. Moreover, reversion mutants also restored other unusual phenotypes that strain 1386 displayed, i.e. altered colony morphology, impaired biofilm development, and reduced acid resistance. Transcriptional analysis at stationary phase with buffered BHI media revealed that trehalose metabolism positively influences the transcription of genes encoding amino acid-based acid resistance mechanisms. In summary, our results demonstrated that N352 is key to the function of the sole trehalose transporter TreB in L. monocytogenes and suggest that trehalose metabolism alters physiology to favour biofilm development and acid stress resistance. Moreover, since strain 1386 is among the strains recommended by the European Union Reference Laboratory for conducting food challenge studies in order to determine whether or not L. monocytogenes can grow in food, these findings have important implications for food safety.}, }
@article {pmid36933236, year = {2023}, author = {Chen, Q and Qi, M and Shi, F and Liu, C and Shi, Y and Sun, Y and Bai, X and Wang, L and Sun, X and Dong, B and Li, C}, title = {Novel Twin-Crystal Nanosheets with MnO2 Modification to Combat Bacterial Biofilm against Periodontal Infections via Multipattern Strategies.}, journal = {Advanced healthcare materials}, volume = {}, number = {}, pages = {e2300313}, doi = {10.1002/adhm.202300313}, pmid = {36933236}, issn = {2192-2659}, abstract = {Nowadays the multifunctional approaches to kill oral bacteria based on various nanocomposites have made great progress against periodontal infections, while the material structure and its functional integration are still insufficient. Herein, we proposed a therapeutic strategy of chemodynamical therapy (CDT) and photothermal therapy (PTT) in monocrystals to effectively enhance the synergistic treatment. The CuS/MnS@MnO2 consisting of hexagonal CuS/MnS nano-twin-crystal with a shell layer of MnO2 was developed. In this nanosystem, the purpose of synergistic treatment of periodontitis by combining PTT/CDT has been achieved within CuS/MnS monocrystal, where CuS served to achieve photothermal conversion, dissipate the biofilm and transfer the heat in situ to the integrated MnS, thus promoting the Mn[2+] -mediated CDT process. Meanwhile, the CDT process could generate the highly toxic hydroxyl radical to destroy extracellular DNA by utilization of endogenous H2 O2 produced by Streptococci in oral biofilm, cooperating with PTT to dissipate bacterial biofilm. With the design of outer shell of MnO2 , the selective bacteria-killing can be realized by producing oxygen which can protect the periodontal non-pathogenic aerobic bacteria and threatened the survival of anaerobic pathogens Therefore, such design via multipattern strategies to combat microorganisms would provide a bright prospect for the clinical treatment of bacterial infections. This article is protected by copyright. All rights reserved.}, }
@article {pmid36931893, year = {2023}, author = {Wang, F and Yuan, J and Wang, X and Xuan, H}, title = {Antibacterial and anti-biofilm activities of chinese Propolis essential oil microemulsion against Streptococcus mutans.}, journal = {Journal of applied microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/jambio/lxad056}, pmid = {36931893}, issn = {1365-2672}, abstract = {AIMS: To solve the shortcomings of poor solubility, easy volatilization and decomposition, propolis essential oil microemulsion (PEOME) was prepared. The antibacterial, anti-biofilm activities and action mechanism of PEOME against Streptococcus mutans was analyzed.<br><br>METHODS: PEOME was prepared using anhydrous ethanol and Tween-80 as the cosurfactant and surfactant respectively. The antibacterial activity of PEOME against Streptococcus mutans was evaluated using the agar disk-diffusion method and broth microdilution method. The effects of PEOME on S. mutans biofilm was detected through the assays of crystal violet (CV), XTT reduction, lactic dehydrogenase (LDH) and calcium ions leaking, live/dead staining and scanning electron microscopy (SEM). And the anti-biofilm mechanism of PEOME was elaborated by the assays of extracellular polysaccharide (EPS) production and glucosyltransferase (GTF) activity.<br><br>RESULTS: The inhibition zone diameter (DIZ) of PEOME against S. mutans was 31&#xa0;mm, while the minimal inhibitory concentration (MIC) was 2.5&#xa0;&#xb5;L mL-1. CV and XTT assays showed that PEOME could prevent fresh biofilm formation and disrupt preformed biofilm through decreasing the activities and biomass of biofilm. The leaking assays for LDH and calcium ions, as well as the live/dead staining assay, indicated that PEOME was able to damage the integrity of bacterial cell membranes within the biofilm. SEM revealed that PEOME had a noticeable inhibitory effect on bacterial adhesion and aggregation through observing the overall structure of biofilm. The assays of EPS production and GTF activity suggested that PEOME could reduce EPS production by inhibiting the activity of GTFs, thus showing an anti-biofilm effect.<br><br>CONCLUSIONS: The significant antibacterial and anti-biofilm activities against S. mutans of PEOME meant that PEOME has great potential to be developed as a drug to prevent and cure dental caries caused by S. mutans.}, }
@article {pmid36931368, year = {2023}, author = {Sindelo, A and Sen, P and Nyokong, T}, title = {Photoantimicrobial activity of Schiff-base Morpholino phthalocyanines against drug resistant micro-organisms in their planktonic and biofilm forms.}, journal = {Photodiagnosis and photodynamic therapy}, volume = {}, number = {}, pages = {103519}, doi = {10.1016/j.pdpdt.2023.103519}, pmid = {36931368}, issn = {1873-1597}, abstract = {Antimicrobial photodynamic inactivation (aPDI) is an alternative treatment for the eradication of drug-resistant micro-organisms. One of the advantages of this technique, it that there is no possibility of microbial resistance. Hence, herein, the preparation and characterization of novel neutral and cationic morpholine containing Schiff base phthalocyanines are reported. The cationic complexes (4 and 5) gave moderate singlet oxygen quantum yields (ΦΔ) of ∼0.2 in aqueous media. Conversely, the neutral complexes generated very low ΦΔ values making them very poor candidates for antimicrobial studies. The cationic phthalocyanines showed excellent photodynamic activity against planktonic cells of all micro-organisms (Candida albicans, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Salmonella enterica subspecies enterica serovar Choleraesuis, vancomycin-resistant E. faecium, and methicillin-resistant Staphylococcus aureus). The efficiency of aPDI was shown to be both concentration and light-dose-dependent. Mono biofilms were susceptible when treated with 200 µM of cationic Pcs at 108 J/cm[2]. However, ∼10% of the mixed biofilm survived after treatment.}, }
@article {pmid36930448, year = {2023}, author = {Yazıcı, BC and Bakhedda, N and Akçelik, N}, title = {Effect of nisin and p-coumaric acid on autoinducer-2 activity, biofilm formation, and sprE expression of Enterococcus faecalis.}, journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]}, volume = {}, number = {}, pages = {}, pmid = {36930448}, issn = {1678-4405}, abstract = {Quorum sensing (QS) is an inter- and intracellular communication mechanism that regulates gene expression in response to population size. Autoinducer-2 (AI-2) signaling is a QS signaling molecule common to both Gram-negative and Gram-positive bacteria. Enterococcus faecalis is one of the leading causes of nosocomial infections worldwide. There has been an increasing interest in controlling infectious diseases through targeting the QS mechanism using natural compounds. This study aimed to investigate the effect of nisin and p-coumaric acid (pCA), on biofilm formation and AI-2 signaling in E. faecalis. Their effect on the expression of the QS-regulated virulence encoding gene sprE was also investigated. Nisin exhibited a MIC ranging from 0.25 to 0.5 mg/mL, while the MIC of pCA was 1 mg/mL. The luminescence-based response of the reporter strain Vibrio harveyi BB170 was used to determine AI-2 activity in E. faecalis strains. Nisin was not effective in inhibiting AI-2 activity, while pCA reduced AI-2 activity by ≥ 60%. Moreover, pCA and nisin combination showed higher inhibitory effect on biofilm formation of E. faecalis, compared to the treatment of pCA or nisin alone. qRT-PCR analysis showed that nisin alone and the combination of nisin and pCA, at their MIC values, led to a 32.78- and 40.22-fold decrease in sprE gene expression, respectively, while pCA alone did not have a significant effect. Considering the demand to explore new therapeutic avenues for infectious bacteria, this study was the first to report that pCA can act like a quorum sensing inhibitor (QSI) against AI-2 signaling in E. faecalis.}, }
@article {pmid36930446, year = {2023}, author = {Baghiat Esfahani, M and Khodavandi, A and Alizadeh, F and Bahador, N}, title = {Biofilm-associated genes as potential molecular targets of nano-Fe3O4 in Candida albicans.}, journal = {Pharmacological reports : PR}, volume = {}, number = {}, pages = {}, pmid = {36930446}, issn = {2299-5684}, abstract = {BACKGROUND: There are few effective treatments for Candida biofilm-associated infections. The present study demonstrated changes in the expression of biofilm-associated genes in Candida albicans treated with magnetic iron oxide nanoparticles (denoted as nano-Fe3O4).<br><br>METHODS: Nano-Fe3O4 was biologically synthesized using Bacillus licheniformis, Bacillus cereus, and Fusarium oxysporum. Additionally, the&#xa0;biologically synthesized nano-Fe3O4 was characterized by visual observation; ultraviolet-visible spectroscopy, scanning electron microscopy, X-ray diffraction spectroscopy, and Fourier transform infrared spectroscopy. The biologically synthesized nano-Fe3O4 was tested for growth and biofilm formation in&#xa0;C. albicans. Furthermore, quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was used to study the inhibition of biofilm-associated genes in C. albicans treated with nano-Fe3O4.<br><br>RESULTS: The production of biologically synthesized nano-Fe3O4 was confirmed using extensive characterization methods. The nano-Fe3O4 inhibited growth and biofilm formation. Nano-Fe3O4 exhibited growth inhibition with minimum inhibition concentrations (MICs) of 50 to 200&#xa0;&#x3bc;g&#xa0;mL[-1]. The anti-biofilm effects of nano-Fe3O4 were shown by 2,3-bis (2-methoxy-4-nitro-5 sulfophenyl)-5-[(phenylamino) carbonyl]-2H-tetrazolium hydroxide (XTT) reduction assay, crystal violet staining, and light field microscopy. The gene expression results showed that the downregulation of&#xa0;BCR1, ALS1, ALS3, HWP1, and ECE1 genes inhibited the biofilm formation in&#xa0;C. albicans. ALS1 reduction was greater than others, with downregulation of 1375.83-, 1178.71-, and 768.47-fold at 2&#x2009;&#xd7;&#x2009;MIC, 1&#x2009;&#xd7;&#x2009;MIC, and &#xbd;&#x2009;&#xd7;&#x2009;MIC of nano-Fe3O4, respectively.<br><br>CONCLUSION: Biofilm-associated genes as potential molecular targets of nano-Fe3O4 in C. albicans may be an effective novel treatment strategy for biofilm-associated infections.}, }
@article {pmid36929684, year = {2023}, author = {Du, X and Ma, M and Zhang, Y and Yu, X and Chen, L and Zhang, H and Meng, Z and Jia, X and Chen, J and Meng, Q and Li, C}, title = {Synthesis of Cationic Biphen[4, 5]arenes as Biofilm Disruptors.}, journal = {Angewandte Chemie (International ed. in English)}, volume = {}, number = {}, pages = {e202301857}, doi = {10.1002/anie.202301857}, pmid = {36929684}, issn = {1521-3773}, abstract = {Since bacteria in biofilms are inherently resistant to antibiotics and biofilm-associated infections pose serious threat to global public health, new therapeutic agents and schemes are urgently needed to meet clinical requirements. Here two quaternary ammonium-functionalized biphen[n]arenes (WBPn, n = 4, 5) were designed and synthesized with excellent anti-biofilm potency. Not only could they inhibit assembly of biofilm, but also eradicate intractable mature biofilm formed by Gram-positive S. aureus and Gram-negative E. coli bacterial strains. Moreover, they could strongly complex a conventional antibiotic, cefazolin sodium (CFZ) with complex stability constants of (7.41 ± 0.29) × 104 M-1 for CFZ/WBP4 and (4.98 ± 0.49) × 103 M-1 for CFZ/WBP5. Combination of CFZ by WBP4 and WBP5 synergistically enhanced biofilm eradication performance in vitro and statistically improved healing efficacy on E. coli-infected mice models, providing novel supramolecular strategy for combating biofilm-associated infections.}, }
@article {pmid36929159, year = {2023}, author = {Kobayashi, A and Nakamura, M and Tsujii, M and Makino, K and Nagayama, T and Nakamura, K and Nanatani, K and Kota, K and Furuuchi, Y and Kayamori, S and Furuta, T and Suzuki, I and Hayakawa, Y and Ellen, T and Ishimaru, Y and Uozumi, N}, title = {Two cyanobacterial response regulators with diguanylate cyclase activity, Rre2 and Rre8, participate in biofilm formation.}, journal = {Molecular microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1111/mmi.15057}, pmid = {36929159}, issn = {1365-2958}, abstract = {Phototrophic bacteria face diurnal variations of environmental conditions such as light and osmolarity, that affect their carbon metabolism and ability to generate organic compounds. The model cyanobacterium, Synechocystis sp. PCC 6803 forms a biofilm when it encounters extreme conditions like high salt stress, but the molecular mechanisms involved in perception of environmental changes that lead to biofilm formation are unknown. Here, we studied two two-component regulatory systems (TCSs) that contain diguanylate cyclases (DGCs), which produce the second messenger c-di-GMP, as potential components of the biofilm-inducing signaling pathway in Synechocystis. Analysis of single mutants provided evidence for involvement of Rre2 and Rre8 in biofilm formation. A bacterial two-hybrid assay showed that the response regulators, Rre2 and Rre8 each formed a TCS with a specific histidine kinase, Hik12 and Hik14, respectively. The in vitro assay showed that Rre2 had DGC activity regardless of its de/phosphorylation status, whereas Rre8 required phosphorylation for DGC activity. Hik14-Rre8 likely functioned as an inducible sensing system in response to environmental change. Biofilm assays with Synechocystis mutants suggested that pairs of hik12-rre2 and hik14-rre8 responded to high salinity-induced biofilm formation. Inactivation of hik12-rre2 and hik14-rre8 did not affect the performance of the light reactions of photosynthesis. These data suggest that Hik12-Rre2 and Hik14-Rre8 participate in biofilm formation in Synechocystis by regulating c-di-GMP production via the DGC activity of Rre2 and Rre8.}, }
@article {pmid36928367, year = {2023}, author = {El-Naggar, NE and Dalal, SR and Zweil, AM and Eltarahony, M}, title = {Artificial intelligence-based optimization for chitosan nanoparticles biosynthesis, characterization and in‑vitro assessment of its anti-biofilm potentiality.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {4401}, pmid = {36928367}, issn = {2045-2322}, abstract = {Chitosan nanoparticles (CNPs) are promising biopolymeric nanoparticles with excellent physicochemical, antimicrobial, and biological properties. CNPs have a wide range of applications due to their unique characteristics, including plant growth promotion and protection, drug delivery, antimicrobials, and encapsulation. The current study describes an alternative, biologically-based strategy for CNPs biosynthesis using Olea europaea leaves extract. Face centered central composite design (FCCCD), with 50 experiments was used for optimization of CNPs biosynthesis. The artificial neural network (ANN) was employed for analyzing, validating, and predicting CNPs biosynthesis using Olea europaea leaves extract. Using the desirability function, the optimum conditions for maximum CNPs biosynthesis were determined theoretically and verified experimentally. The highest experimental yield of CNPs (21.15 mg CNPs/mL) was obtained using chitosan solution of 1%, leaves extract solution of 100%, initial pH 4.47, and incubation time of 60 min at 53.83°C. The SEM and TEM images revealed that CNPs had a spherical form and varied in size between 6.91 and 11.14 nm. X-ray diffraction demonstrates the crystalline nature of CNPs. The surface of the CNPs is positively charged, having a Zeta potential of 33.1 mV. FTIR analysis revealed various functional groups including C-H, C-O, CONH2, NH2, C-OH and C-O-C. The thermogravimetric investigation indicated that CNPs are thermally stable. The CNPs were able to suppress biofilm formation by P. aeruginosa, S. aureus and C. albicans at concentrations ranging from 10 to 1500 µg/mL in a dose-dependent manner. Inhibition of biofilm formation was associated with suppression of metabolic activity, protein/exopolysaccharide moieties, and hydrophobicity of biofilm encased cells (r ˃ 0.9, P = 0.00). Due to their small size, in the range of 6.91 to 11.14 nm, CNPs produced using Olea europaea leaves extract are promising for applications in the medical and pharmaceutical industries, in addition to their potential application in controlling multidrug-resistant microorganisms, especially those associated with post COVID-19 pneumonia in immunosuppressed patients.}, }
@article {pmid36926839, year = {2023}, author = {Bird, LJ and Leary, DH and Hervey, J and Compton, J and Phillips, D and Tender, LM and Voigt, CA and Glaven, SM}, title = {Marine Biofilm Engineered to Produce Current in Response to Small Molecules.}, journal = {ACS synthetic biology}, volume = {}, number = {}, pages = {}, doi = {10.1021/acssynbio.2c00417}, pmid = {36926839}, issn = {2161-5063}, abstract = {Engineered electroactive bacteria have potential applications ranging from sensing to biosynthesis. In order to advance the use of engineered electroactive bacteria, it is important to demonstrate functional expression of electron transfer modules in chassis adapted to operationally relevant conditions, such as non-freshwater environments. Here, we use the Shewanella oneidensis electron transfer pathway to induce current production in a marine bacterium, Marinobacter atlanticus, during biofilm growth in artificial seawater. Genetically encoded sensors optimized for use in Escherichia coli were used to control protein expression in planktonic and biofilm attached cells. Significant current production required the addition of menaquinone, which M. atlanticus does not produce, for electron transfer from the inner membrane to the expressed electron transfer pathway. Current through the S. oneidensis pathway in M. atlanticus was observed when inducing molecules were present during biofilm formation. Electron transfer was also reversible, indicating that electron transfer into M. atlanticus could be controlled. These results show that an operationally relevant marine bacterium can be genetically engineered for environmental sensing and response using an electrical signal.}, }
@article {pmid36926823, year = {2023}, author = {Estes Bright, LM and Garren, MRS and Douglass, M and Handa, H}, title = {Synthesis and Characterization of Nitric Oxide-Releasing Ampicillin as a Potential Strategy for Combatting Bacterial Biofilm Formation.}, journal = {ACS applied materials &amp; interfaces}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsami.3c00140}, pmid = {36926823}, issn = {1944-8252}, abstract = {Biofilm formation on biomaterial interfaces and the development of antibiotic-resistant bacteria have decreased the effectiveness of traditional antibiotic treatment of infections. In this project, ampicillin, a commonly used antibiotic, was conjugated with S-nitroso-N-acetylpenicillamine (SNAP), an S-nitrosothiol compound (RSNO) used for controlled nitric oxide (NO) release. This novel multifunctional molecule is the first of its kind to provide combined antibiotic and NO treatment of infectious pathogens. Characterization of the molecule included NMR, FTIR, and mass spectrometry. NO release behavior was also measured and compared to pure, unmodified SNAP. When evaluating the antimicrobial efficacy, the synthesized SNAPicillin molecule showed the lowest MIC value against Gram-negative Pseudomonas aeruginosa and Gram-positive methicillin-resistant Staphylococcus aureus compared to ampicillin and SNAP alone. SNAPicillin also displayed enhanced biofilm dispersal and killing of both bacterial strains when treating a 48 h biofilm preformed on a polymer surface. The antibacterial results combined with the biocompatibility of the molecule show great promise for infection prevention and treatment of polymeric interfaces to reduce medical device-related infections.}, }
@article {pmid36926513, year = {2023}, author = {Varma, A and Warghane, A and Dhiman, NK and Paserkar, N and Upadhye, V and Modi, A and Saini, R}, title = {The role of nanocomposites against biofilm infections in humans.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1104615}, pmid = {36926513}, issn = {2235-2988}, abstract = {The use of nanomaterials in several fields of science has undergone a revolution in the last few decades. It has been reported by the National Institutes of Health (NIH) that 65% and 80% of infections are accountable for at least 65% of human bacterial infections. One of their important applications in healthcare is the use of nanoparticles (NPs) to eradicate free-floating bacteria and those that form biofilms. A nanocomposite (NC) is a multiphase stable fabric with one or three dimensions that are much smaller than 100 nm, or systems with nanoscale repeat distances between the unique phases that make up the material. Using NC materials to get rid of germs is a more sophisticated and effective technique to destroy bacterial biofilms. These biofilms are refractory to standard antibiotics, mainly to chronic infections and non-healing wounds. Materials like graphene and chitosan can be utilized to make several forms of NCs, in addition to different metal oxides. The ability of NCs to address the issue of bacterial resistance is its main advantage over antibiotics. This review highlights the synthesis, characterization, and mechanism through which NCs disrupt Gram-positive and Gram-negative bacterial biofilms, and their relative benefits and drawbacks. There is an urgent need to develop materials like NCs with a larger spectrum of action due to the rising prevalence of human bacterial diseases that are multidrug-resistant and form biofilms.}, }
@article {pmid36924752, year = {2023}, author = {Sterniša, M and Gradišar Centa, U and Drnovšek, A and Remškar, M and Smole Možina, S}, title = {Pseudomonas fragi biofilm on stainless steel (at low temperatures) affects the survival of Campylobacter jejuni and Listeria monocytogenes and their control by a polymer molybdenum oxide nanocomposite coating.}, journal = {International journal of food microbiology}, volume = {394}, number = {}, pages = {110159}, doi = {10.1016/j.ijfoodmicro.2023.110159}, pmid = {36924752}, issn = {1879-3460}, abstract = {Pseudomonas spp. are widely distributed bacteria on surfaces in the food production and processing environment, where they form extracellular polymeric substance rich biofilms that interact with other bacteria. In this study, the influence of biofilm of Pseudomonas fragi ATCC 4973 on Listeria monocytogenes ATCC 19115 and Campylobacter jejuni NCTC 11168 was investigated at 5 °C and 15 °C on stainless steel in broth and food homogenates (fish or chicken meat). Stainless steel was then coated with PVDF-HFP/PVP/MoO3 nanocomposite and examined for surface changes (scanning electron microscope, static contact angle, Vickers hardness and elastic modulus). The effect of the prepared nanocomposite coating on P. fragi and on L. monocytogenes and C. jejuni was evaluated in mono- and co-culture. P. fragi produced more biofilm at 15 °C than at 5 °C, especially when food homogenates were used as growth media. Co-cultivation with pathogens did not affect biofilm production by P. fragi, but significant changes were observed in L. monocytogenes and C. jejuni, resulting in a decrease and increase, respectively, in the determined number of culturable biofilm cells. The first change was probably due to competition for the surface, and the second to the oxygen gradient. Stainless steel was then coated with a PVDF-HFP/PVP/MoO3 nanocomposite, which was characterised by lower roughness and higher wettability, but lower hardness compared to uncoated stainless steel. The prepared nanocoating showed bactericidal activity when tested in phosphate buffered saline. When used in food homogenates, a reduction of over 95 % in bacterial counts was observed. An abundant biofilm of P. fragi proved protective to L. monocytogenes and C. jejuni against the functionalised nanocomposite surface when tested in food homogenates. The control of spoilage Pseudomonas spp., which are common in the food production and processing environment, is important for reducing the contamination of food with spoilage bacteria and with pathogens such as L. monocytogenes and C. jejuni, which may be present in the same environment. The PVDF-HFP/PVP/MoO3 nanocomposite showed good potential for use as a coating for food contact surfaces, but possible migration of nanoparticles from the nanocomposite coating to food should be evaluated before its commercial use.}, }
@article {pmid36922940, year = {2023}, author = {Diaz, A and Dixit, AR and Khodadad, CL and Hummerick, ME and Justiano-Velez, YA and Li, W and O'Rourke, A}, title = {Biofilm formation is correlated with low nutrient and simulated microgravity conditions in a Burkholderia isolate from the ISS water processor assembly.}, journal = {Biofilm}, volume = {5}, number = {}, pages = {100110}, pmid = {36922940}, issn = {2590-2075}, abstract = {The International Space Station (ISS) Water Processor Assembly (WPA) experiences intermittent dormancy in the WPA wastewater tank during water recycling events which promotes biofilm formation within the system. In this work we aimed to gain a deeper understanding of the impact of nutrient limitation on bacterial growth and biofilm formation under microgravity in support of biofilm mitigation efforts in exploration water recovery systems. A representative species of bacteria that is commonly cultured from the ISS WPA was cultured in an WPA influent water ersatz formulation tailored for microbiological studies. An isolate of Burkholderia contaminans was cultured under a simulated microgravity (SμG) treatment in a vertically rotating high-aspect rotating vessel (HARV) to create the low shear modeled microgravity (LSMMG) environment on a rotating wall vessel (RWV), with a rotating control (R) in the horizontal plane at the predetermined optimal rotation per minute (rpm) speed of 20. Over the course of the growth curve, the bacterial culture in ersatz media was harvested for bacterial counts, and transcriptomic and nutrient content analyses. The cultures under SμG treatment showed a transcriptomic signature indicative of nutrient stress and biofilm formation as compared to the R control treatment. Further analysis of the WPA ersatz over the course of the growth curve suggests that the essential nutrients of the media were consumed faster in the early stages of growth for the SμG treatment and thus approached a nutrient limited growth condition earlier than in the R control culture. The observed limited nutrient response may serve as one element to explain a moderate enhancement of adherent biofilm formation in the SμG treatment after 24 h. While nutrients levels can be modulated, one implication of this investigation is that biofilm mitigation in the ISS environment could benefit from methods such as mixing or the maintenance of minimum flow within a dormant water system in order to force convection and offset the response of microbes to the secondary effects of microgravity.}, }
@article {pmid36922440, year = {2023}, author = {Ji, C and Wang, H and Cui, H and Zhang, C and Li, R and Liu, T}, title = {Characterization and evaluation of substratum material selection for microalgal biofilm cultivation.}, journal = {Applied microbiology and biotechnology}, volume = {}, number = {}, pages = {}, pmid = {36922440}, issn = {1432-0614}, abstract = {Biofilm cultivation is considered a promising method to achieve higher microalgae biomass productivity with less water consumption and easier harvest compared to conventional suspended cultivation. However, studies focusing on the selection of substratum material and optimization of the growth of certain microalgae species on specific substratum are limited. This study investigated the selection of membranous and fabric fiber substrata for the attachment of unicellular microalgae Scenedesmus dimorphus and filamentous microalgae Tribonema minus in biofilm cultivation. The results indicated that both algal species preferred hydrophilic membranous substrata and nitrate cellulose/cellulose acetate membrane (CN-CA) was selected as a suitable candidate on which the obtained biomass yields were up to 10.24 and 7.81 g m[-2] day[-1] for S. dimorphus and T. minus, respectively. Furthermore, high-thread cotton fiber (HCF) and low-thread polyester fiber (LPEF) were verified as the potential fabric fiber substrata for S. dimorphus (5.42 g m[-2] day[-1]) and T. minus (5.49 g m[-2] day[-1]) attachment, respectively. The regrowth of microalgae biofilm cultivation strategy was applied to optimize the algae growth on the fabric fiber substrata, with higher biomass density and shear resistibility achieved for both algal species. The present data highlight the importance to establish the standards for selection the suitable substratum materials in ensuring the high efficiency and sustainability of the attached microalgal biomass production. KEY POINTS: • CN-CA was suitable membranous substratum candidate for algal biofilm cultivation. • HCF and LPEF were potential fabric fiber substrata for S. dimorphus and T. minus. • Regrowth biofilm cultivation was effective in improving algal biomass and attachment.}, }
@article {pmid36921788, year = {2023}, author = {Yadav, S and Tripathi, S and Purchase, D and Chandra, R}, title = {Development of a biofilm-forming bacterial consortium and quorum sensing molecules for the degradation of lignin-containing organic pollutants.}, journal = {Environmental research}, volume = {}, number = {}, pages = {115618}, doi = {10.1016/j.envres.2023.115618}, pmid = {36921788}, issn = {1096-0953}, abstract = {Due to presence of lignin along with other pollutants makes effluent more complex which is discharged from Pulp and paper mills. The present study investigates the use of biofilm-forming bacteria isolated from pulp paper mill effluent contaminated sites (PPMECSs) for lignin degradation. Isolated biofilm-forming and lignin-degrading bacteria were identified as Bacillus subtilis, Enterobacter cancerogenus, and Bacillus licheniformis by 16S rRNA gene sequencing. Thin liquid chromatography (TLC) analysis showed that the consortium of bacteria produced acyl-homoserine lactone (AHL) as quorum sensing molecules and extracellular polymeric substances (EPS) that protect the bacterial consortium under unfavorable conditions. The potential consortium was able to reduce lignin (900 ppm) by 73% after 8 days of incubation in a minimal salt medium containing kraft lignin and glucose at pH 7.0 and 37 °C as compared to individual strains. The degradation by-products were identified as amides, alcohols, and acids. The major organic pollutants in the effluent were reduced after treatment of the constructed consortium, thus confirming active biotransformation and biodegradation of the lignin. Microscopic examination also indicated the presence of lignin induced biofilm formation. Hence, the constructed biofilm-forming bacterial consortia based on quorum sensing offered a sustainable and effective solution to treat lignin-containing complex pollutants.}, }
@article {pmid36921636, year = {2023}, author = {Yang, L and Pang, S and Zhou, J and Li, X and Yao, M and Xia, S}, title = {Biological Reduction and Hydrodechlorination of Chlorinated Nitroaromatic Antibiotic Chloramphenicol under H2-Transfer Membrane Biofilm Reactor.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {128881}, doi = {10.1016/j.biortech.2023.128881}, pmid = {36921636}, issn = {1873-2976}, abstract = {Chlorinated nitroaromatic antibiotic chloramphenicol (CAP) is a persistent pollutant that is widely present in environments. A H2 transfer membrane biofilm reactor (H2-MBfR) and short-term batch tests were setup to investigate the co-removal of CAP and NO- 3. Results showed that the presence of CAP (< 10 mg L[-1]) has no effect on the denitrification process while 100% removal efficiency of CAP can be obtained when nitrate was absent. Nitroaromatic reduction and completely dechlorination were successfully realized when CAP was removed. The CAP transformation product p-aminobenzoic acid (PABA) was detected and batch tests revealed that the hydroxy carboxylation was far faster than nitroaromatic reduction when p-nitrobenzyl alcohol (PNBOH) was conversed to p-aminobenzoic acid (PABA). The path way of CAP degradation was proposed based on the intermediate's analysis. Microbial community analysis indicated that Pleomorphomonadaceae accounts for the dechlorination of CAP.}, }
@article {pmid36921483, year = {2023}, author = {Zeng, X and Mo, Z and Zheng, J and Wei, C and Dai, Y and Yan, Y and Qiu, S}, title = {Effects of biofilm and co-culture with Bacillus velezensis on the synthesis of esters in the strong flavor Baijiu.}, journal = {International journal of food microbiology}, volume = {394}, number = {}, pages = {110166}, doi = {10.1016/j.ijfoodmicro.2023.110166}, pmid = {36921483}, issn = {1879-3460}, abstract = {Biofilm plays an important role in resisting the adverse environment, improving the taste and texture, and promoting the synthesis of flavor substances. However, to date, the findings on the effect of biofilm and dominating bacteria Bacillus on the ester synthesis in the Baijiu field have been largely lacked. Therefore, the objectives of the present study were to primarily isolate biofilm-producing microbes in the fermented grains, evaluate the stress tolerance capacity, and unveil the effect of biofilm and co-culture with Bacillus on the ester synthesis in the strong flavor Baijiu. Results indicated that after isolation and evaluation of stress-tolerance capacity, bacterial strain BG-5 and yeast strains YM-21 and YL-10 were demonstrated as mediate or strong biofilm-producing microbes and were identified as Bacillus velezensis, Saccharomycopsis fibuligera, and Zygosaccharomyces bailii, respectively. Solid phase microextraction/gas chromatography-mass spectrometer indicated that biofilm could enhance the diversity of esters while reduce the contents of ester. The scanning electron microscopy showed an inhibitory effect of B. velezensis on the growth of S. fibuligera, further restraining the production of esters. Taken together, both biofilm and B. velezensis influence the ester synthesis process. The present study is the first to reveal the biofilm-producing microorganisms in fermented grains and to preliminarily investigate the effect of biofilm on the ester synthesis in the Baijiu field.}, }
@article {pmid36920192, year = {2023}, author = {Al-Shamiri, MM and Wang, J and Zhang, S and Li, P and Odhiambo, WO and Chen, Y and Han, B and Yang, E and Xun, M and Han, L and Han, S}, title = {Probiotic Lactobacillus Species and Their Biosurfactants Eliminate Acinetobacter baumannii Biofilm in Various Manners.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0461422}, doi = {10.1128/spectrum.04614-22}, pmid = {36920192}, issn = {2165-0497}, abstract = {Acinetobacter baumannii is a critical biofilm-forming pathogen that has presented great challenges in the clinic due to multidrug resistance. Thus, new methods of intervention are needed to control biofilm-associated infections. In this study, among three tested Lactobacillus species, Lactobacillus rhamnosus showed significant antimaturation and antiadherence effects against A. baumannii biofilm. Lactic acid (LA) and acetic acid (AA) were the most effective antibiofilm biosurfactants (BSs) produced by L. rhamnosus. This antibiofilm phenomenon produced by LA and AA was due to the strong bactericidal effect, which worked from very early time points, as determined by colony enumeration and confocal laser scanning microscope. The cell destruction of A. baumannii appeared in both the cell envelope and cytoplasm. A discontinuous cell envelope, the leakage of cell contents, and the increased extracellular activity of ATPase demonstrated the disruption of the cell membrane by LA and AA. These effects also demonstrated the occurrence of protein lysis. In addition, bacterial DNA interacted with and was damaged by LA and AA, resulting in significantly reduced expression of biofilm and DNA repair genes. The results highlight the possibility and importance of using probiotics in clinical prevention. Probiotics can be utilized as novel biocides to block and decrease biofilm formation and microbial contamination in medical equipment and during the treatment of infections. IMPORTANCE A. baumannii biofilm is a significant virulence factor that causes the biofilm colonization of invasive illnesses. Rising bacterial resistance to synthetic antimicrobials has prompted researchers to look at natural alternatives, such as probiotics and their derivatives. In this study, L. rhamnosus and its BSs (LA and AA) demonstrated remarkable antibiofilm and antimicrobial characteristics, with a significant inhibitory effect on A. baumannii. These effects were achieved by several mechanisms, including the disruption of the cell envelope membrane, protein lysis, reduced expression of biofilm-related genes, and destruction of bacterial DNA. The results provide support for the possibility of using probiotics and their derivatives in the clinical prevention and therapy of A. baumannii infections.}, }
@article {pmid36916551, year = {2023}, author = {Nguyen Trang, P and Thi Anh Ngoc, T and Masuda, Y and Hohjoh, KI and Miyamoto, T}, title = {Biofilm Formation From Listeria monocytogenes Isolated From Pangasius Fish-processing Plants.}, journal = {Journal of food protection}, volume = {86}, number = {3}, pages = {100044}, doi = {10.1016/j.jfp.2023.100044}, pmid = {36916551}, issn = {1944-9097}, mesh = {Animals ; *Listeria monocytogenes ; Muramidase/pharmacology ; Chlorine/pharmacology ; Polylysine/pharmacology ; Stainless Steel ; Biofilms ; *Catfishes ; Water/pharmacology ; Colony Count, Microbial ; }, abstract = {Biofilm formation of Listeria monocytogenes in food processing environments cause potential source of cross-contamination to foodstuffs; hence, the control of biofilm is currently addressed to find effective solutions for preventing biofilm formation or eliminating the established one. Forty-five strains of Listeria monocytogenes isolated from Pangasius fish-processing plants were studied for their capability to form a biofilm on 96-well microtiter plate by using the conventional crystal violet staining. Additionally, the inhibitory effect of biofilm formation by food additives including monascus pigment and ε-polylysine was examined. The average OD value showing biofilm mass of all 45 strains L. monocytogenes increased with an increasing temperature and time (p < 0.05). Monascus pigment and ε-polylysine significantly decreased biofilm formation by 80 ± 5.5% and 20 ± 5.9%, respectively, at the tested concentration (p < 0.05) Further, the effects of lysozyme (0.1 mg/mL) alone or in combination with slightly acidic hypochlorous water (SAHW) with 40 mg/L available chlorine or sodium hypochlorite (NaOCl) with 100 mg/L available chlorine against 7-d established biofilm of L. monocytogenes were investigated. The results indicated that slightly acidic hypochlorous water alone exhibited significant antibacterial activity (p < 0.05), decreasing the viable count by 5.2 ± 0.5 log CFU/mL. It seems that sequential treatment of lysozyme and SAHW showed an additional efficacy against biofilm of L. monocytogenes on polystyrene plate surface, reducing 70% of biomass of biofilm and 7.6 ± 0.3 log of biofilm viable cells (p < 0.05). Additionally, SAHW exhibited greater bactericidal activity against viable biofilm cells than NaOCl did. This result reveals that SAHW is a promising disinfectant agent against L. monocytogenes and the potential alternative to NaOCl in practice.}, }
@article {pmid36914689, year = {2023}, author = {Bano, N and Iqbal, D and Al Othaim, A and Kamal, M and Albadrani, HM and Algehainy, NA and Alyenbaawi, H and Alghofaili, F and Amir, M and Roohi, }, title = {Antibacterial efficacy of synthesized silver nanoparticles of Microbacterium proteolyticum LA2(R) and Streptomyces rochei LA2(O) against biofilm forming meningitis causing microbes.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {4150}, pmid = {36914689}, issn = {2045-2322}, mesh = {Humans ; Silver/pharmacology/chemistry ; *Metal Nanoparticles/chemistry ; Anti-Bacterial Agents/chemistry ; *Streptomyces ; Biofilms ; *Actinomycetales ; *Actinobacteria ; *Meningitis ; Microbial Sensitivity Tests ; }, abstract = {Actinobacteria obtained from the least explored Indian regions were studied for their ability to suppress meningitis-causing bacteria in nanoparticle form. Drug-resistant bacteria and long-term treatment with different medications make meningitis control complicated. Thus, new meningitis drugs are required to combat MDR bacteria. In this study, secondary metabolites isolated from actinomycetes strains, Microbacterium proteolyticum LA2(R) and Streptomyces rochei LA2(O), were employed to synthesize silver nanoparticles (AgNPs) at 37 °C for seven days incubation. UV-Vis spectroscopy, TEM, FTIR, and HPLC studies were used for the confirmation of the synthesis of AgNPs. Furthermore, these NPs demonstrated antibacterial and antibiofilm activities against meningitis-causing bacteria. The average size of LA2(R) and LA2(O) isolated secondary metabolites mediated AgNPs was observed to be 27 ± 1and 29 ± 2 nm by TEM analysis. FTIR study of RAgNPs and OAgNPs revealed that presence of peaks with positions of 1637.17 cm[1] and 1636.10 cm[1] for C=O amide group appearances in the amide I linkage. These NPs were effective against bacterial pathogens such as S. pneumoniae, H. influenzae, and N. meningitidis and confirmed by their MICs, i.e., 109.4, 120.60, and 138.80 μg/ml of RAgNPs and 105.80, 114.40 and 129.06 μg/ml of OAgNPs, respectively. Additionally, the production of biofilms is impeded by these nanoparticles on S. pneumoniae, H. influenzae, and N. meningitidis by 73.14%, 71.89% and 64.81%, respectively. These findings confirm the potential role of synthesized AgNPs against biofilm forming meningitis causing Multidrug resistance (MDR) microbes.}, }
@article {pmid36914349, year = {2023}, author = {Wang, D and Fletcher, GC and Gagic, D and On, SLW and Palmer, JS and Flint, SH}, title = {Comparative genome identification of accessory genes associated with strong biofilm formation in Vibrio parahaemolyticus.}, journal = {Food research international (Ottawa, Ont.)}, volume = {166}, number = {}, pages = {112605}, doi = {10.1016/j.foodres.2023.112605}, pmid = {36914349}, issn = {1873-7145}, mesh = {*Vibrio parahaemolyticus/genetics ; Biofilms ; Genomics ; Operon ; Cellulose ; }, abstract = {Vibrio parahaemolyticus biofilms on the seafood processing plant surfaces are a potential source of seafood contamination and subsequent food poisoning. Strains differ in their ability to form biofilm, but little is known about the genetic characteristics responsible for biofilm development. In this study, pangenome and comparative genome analysis of V. parahaemolyticus strains reveals genetic attributes and gene repertoire that contribute to robust biofilm formation. The study identified 136 accessory genes that were exclusively present in strong biofilm forming strains and these were functionally assigned to the Gene Ontology (GO) pathways of cellulose biosynthesis, rhamnose metabolic and catabolic processes, UDP-glucose processes and O antigen biosynthesis (p < 0.05). Strategies of CRISPR-Cas defence and MSHA pilus-led attachment were implicated via Kyoto Encyclopedia of Genes and Genomes (KEGG) annotation. Higher levels of horizontal gene transfer (HGT) were inferred to confer more putatively novel properties on biofilm-forming V. parahaemolyticus. Furthermore, cellulose biosynthesis, a neglected potential virulence factor, was identified as being acquired from within the order Vibrionales. The cellulose synthase operons in V. parahaemolyticus were examined for their prevalence (22/138, 15.94 %) and were found to consist of the genes bcsG, bcsE, bcsQ, bcsA, bcsB, bcsZ, bcsC. This study provides insights into robust biofilm formation of V. parahaemolyticus at the genomic level and facilitates: identification of key attributes for robust biofilm formation, elucidation of biofilm formation mechanisms and development of potential targets for novel control strategies of persistent V. parahaemolyticus.}, }
@article {pmid36914121, year = {2023}, author = {Rožman, M and Lekunberri, I and Grgić, I and Borrego, CM and Petrović, M}, title = {Effects of combining flow intermittency and exposure to emerging contaminants on the composition and metabolic response of streambed biofilm bacterial communities.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {162818}, doi = {10.1016/j.scitotenv.2023.162818}, pmid = {36914121}, issn = {1879-1026}, abstract = {Freshwater ecosystems are characterised by the co-occurrence of stressors that simultaneously affect the biota. Among these, flow intermittency and chemical pollution severely impair the diversity and functioning of streambed bacterial communities. Using an artificial streams mesocosm facility, this study examined how desiccation and pollution caused by emerging contaminants affect the composition of stream biofilm bacterial communities, their metabolic profiles, and interactions with their environment. Through integrative analysis of the composition of biofilm communities, characterization of their metabolome and composition of the dissolved organic matter, we found strong genotype-to-phenotype interconnections. The strongest correlation was found between the composition and metabolism of the bacterial community, both of which were influenced by incubation time and desiccation. Unexpectedly, no effect of the emerging contaminants was observed, which was due to the low concentration of the emerging contaminants and the dominant impact of desiccation. However, biofilm bacterial communities modified the chemical composition of their environment under the effect of pollution. Considering the tentatively identified classes of metabolites, we hypothesised that the biofilm response to desiccation was mainly intracellular while the response to chemical pollution was extracellular. The present study demonstrates that metabolite and dissolved organic matter profiling may be effectively integrated with compositional analysis of stream biofilm communities to yield a more complete picture of changes in response to stressors.}, }
@article {pmid36913883, year = {2023}, author = {Bajaj, A and Abutoama, M and Isaacs, S and Abuleil, MJ and Yaniv, K and Kushmaro, A and Modic, M and Cvelbar, U and Abdulhalim, I}, title = {Biofilm growth monitoring using guided wave ultralong-range Surface Plasmon Resonance: A proof of concept.}, journal = {Biosensors &amp; bioelectronics}, volume = {228}, number = {}, pages = {115204}, doi = {10.1016/j.bios.2023.115204}, pmid = {36913883}, issn = {1873-4235}, abstract = {Unwelcomed biofilms are problematic in food industries, surgical devices, marine applications, and wastewater treatment plants, essentially everywhere where there is moisture. Very recently, label-free advanced sensors such as localized and extended surface plasmon resonance (SPR) have been explored as tools for monitoring biofilm formation. However, conventional noble metal SPR substrates suffer from low penetration depth (100-300 nm) into the dielectric medium above the surface, preventing the reliable detection of large entities of single or multi-layered cell assemblies like biofilms which can grow up to a few micrometers or more. In this study, we propose using a plasmonic insulator-metal-insulator (IMI) structure (SiO2-Ag-SiO2) with a higher penetration depth based on a diverging beam single wavelength format of Kretschmann configuration in a portable SPR device. An SPR line detection algorithm for locating the reflectance minimum of the device helps to view changes in refractive index and accumulation of the biofilm in real-time down to 10[-7] RIU precision. The optimized IMI structure exhibits strong penetration dependence on wavelength and incidence angle. Within the plasmonic resonance, different angles penetrate different depths, showing a maximum near the critical angle. At the wavelength of 635 nm, a high penetration depth of more than 4 μm was obtained. Compared to a thin gold film substrate, for which the penetration depth is only ∼200 nm, the IMI substrate provides more reliable results. The average thickness of the biofilm after 24 h of growth was found to be between 6 and 7 μm with ∼63% live cell volume, as estimated from confocal microscopic images using an image processing tool. To explain this saturation thickness, a graded index biofilm structure is proposed in which the refractive index decreases with the distance from the interface. Furthermore, when plasma-assisted degeneration of biofilms was studied in a semi-real-time format, there was almost no effect on the IMI substrate compared to the gold substrate. The growth rate over the SiO2 surface was higher than on gold, possibly due to differences between surface charge effects. On the gold, the excited plasmon generates an oscillating cloud of electrons, while for the SiO2 case, this does not happen. This methodology can be utilized to detect and characterize biofilms with better signal reliability with respect to concentration and size dependence.}, }
@article {pmid36913810, year = {2023}, author = {Yan, X and Sun, J and Wang, Y and Zhang, Z and Zhang, C and Li, W and Xu, J and Dai, X and Ni, BJ}, title = {Low-rate ferrate dosing damages the microbial biofilm structure through humic substances destruction and facilitates the sewer biofilm control.}, journal = {Water research}, volume = {235}, number = {}, pages = {119834}, doi = {10.1016/j.watres.2023.119834}, pmid = {36913810}, issn = {1879-2448}, abstract = {The microbial activities in sewer biofilms are recognized as a major reason for sewer pipe corrosion, malodor, and greenhouse gas emissions. However, conventional methods to control sewer biofilm activities were based on the inhibitory or biocidal effect of chemicals and often required long exposure time or high dosing rates due to the protection of sewer biofilm structure. Therefore, this study attempt to use ferrate (Fe(VI)), a green and high-valent iron, at low dosing rates to damage the sewer biofilm structure so as to enhance sewer biofilm control efficiency. The results showed the biofilm structure started to crush when the Fe(VI) dosage was 15 mg Fe(VI)/L and the damage enhanced with the increasing dosage. The determination of extracellular polymeric substances (EPS) showed that Fe(VI) treatment at 15-45 mgFe/L mainly decreased the content of humic substances (HS) in biofilm EPS. This is because the functional groups, such as C-O, -OH, and C=O, which held the large molecular structure of HS, were the primary target of Fe(VI) treatment as suggested by 2D-Fourier Transform Infrared spectra. As a result, the coiled chain of EPS maintained by HS was turned to extended and dispersed and consequently led to a loosed biofilm structure. The XDLVO analysis suggested that both the microbial interaction energy barrier and secondary energy minimum were increased after Fe(VI) treatment, suggesting that the treated biofilm was less likely to aggregate and easier to be removed by the shear stress caused by high wastewater flow. Moreover, combined Fe(VI) and free nitrous acid (FNA) dosing experiments showed for achieving 90% inactivation, the FNA dosing rate could be reduced by 90% with the exposure time decreasing by 75% at a low Fe(VI) dosing rate and the total cost was substantially decreased. These results suggested that applying low-rate Fe(VI) dosing for sewer biofilm structure destruction is expected to be an economical way to facilitate sewer biofilm control.}, }
@article {pmid36913408, year = {2023}, author = {Bing, J and Guan, Z and Zheng, T and Zhang, Z and Fan, S and Ennis, CL and Nobile, CJ and Huang, G}, title = {Clinical isolates of Candida auris with enhanced adherence and biofilm formation due to genomic amplification of ALS4.}, journal = {PLoS pathogens}, volume = {19}, number = {3}, pages = {e1011239}, doi = {10.1371/journal.ppat.1011239}, pmid = {36913408}, issn = {1553-7374}, abstract = {Candida auris is an emerging multidrug-resistant fungal pathogen and a new global threat to human health. A unique morphological feature of this fungus is its multicellular aggregating phenotype, which has been thought to be associated with defects in cell division. In this study, we report a new aggregating form of two clinical C. auris isolates with increased biofilm forming capacity due to enhanced adherence of adjacent cells and surfaces. Unlike the previously reported aggregating morphology, this new aggregating multicellular form of C. auris can become unicellular after treatment with proteinase K or trypsin. Genomic analysis demonstrated that amplification of the subtelomeric adhesin gene ALS4 is the reason behind the strain's enhanced adherence and biofilm forming capacities. Many clinical isolates of C. auris have variable copy numbers of ALS4, suggesting that this subtelomeric region exhibits instability. Global transcriptional profiling and quantitative real-time PCR assays indicated that genomic amplification of ALS4 results in a dramatic increase in overall levels of transcription. Compared to the previously characterized nonaggregative/yeast-form and aggregative-form strains of C. auris, this new Als4-mediated aggregative-form strain of C. auris displays several unique characteristics in terms of its biofilm formation, surface colonization, and virulence.}, }
@article {pmid36911973, year = {2023}, author = {Ürer, EK and Aslantaş, &#xd6; and Tek, E and Yılmaz, MA and Ergün, Y}, title = {Antimicrobial susceptibility and biofilm forming ability of staphylococci from subclinical buffalo mastitis.}, journal = {The Journal of dairy research}, volume = {}, number = {}, pages = {1-4}, doi = {10.1017/S0022029923000080}, pmid = {36911973}, issn = {1469-7629}, abstract = {The starting objective of this research communication was to determine the prevalence of subclinical mastitis in buffalo in Turkey. We also seeked to isolate and identify staphylococci, determine their antimicrobial susceptibilities and biofilm-forming abilities as well as investigating the presence of biofilm-related genes and microbial surface components recognizing adhesive matrix molecules. A total of 107 (66.9%) staphylococci (28 S. aureus and 79 coagulase-negative staphylococci, CoNS) were isolated from 160 mastitic milk samples collected from 200 lactating water buffalos. The staphylococci were especially resistant to beta-lactams except for cefoxitin but were less resistant to the other antimicrobials that were tested. Based on the Congo red agar method, 92.9% of the S. aureus and 70.9% of the CoNS isolates were positive for biofilm-forming ability, while all S. aureus and 97.5% of CoNS isolates were positive by a microtiter plate analysis. The presence of icaA and icaD genes was not always correlated with biofilm synthesis, and even in the absence of these genes, the isolates were able to synthesize biofilm.}, }
@article {pmid36911868, year = {2023}, author = {Fukushima, S and Yamamoto, K and Nakano, Y and Hagiya, H and Otsuka, F}, title = {Biofilm-associated candidal thrombophlebitis.}, journal = {IDCases}, volume = {31}, number = {}, pages = {e01733}, pmid = {36911868}, issn = {2214-2509}, }
@article {pmid36911333, year = {2023}, author = {Kim, JY and Moon, EC and Kim, JY and Kim, HJ and Heo, K and Shim, JJ and Lee, JL}, title = {Lactobacillus helveticus HY7801 ameliorates bacterial vaginosis by inhibiting biofilm formation and epithelial cell adhesion of Gardnerella vaginalis.}, journal = {Food science and biotechnology}, volume = {32}, number = {4}, pages = {507-515}, pmid = {36911333}, issn = {2092-6456}, abstract = {UNLABELLED: Bacterial vaginosis (BV) is caused by a microbial imbalance in the vaginal ecosystem, which causes genital discomfort and a variety of potential complications in women. This study validated the potential of Lactobacillus helveticus HY7801 as a probiotic to benefit vaginal health. In vivo, HY7801 reduced the number of Gardnerella vaginalis (GV) and pro-inflammatory cytokines in the vagina of GV-induced BV mice and ameliorated vaginal histological changes. In vitro, HY7801 exhibited positive resistance to simulated gastrointestinal conditions, showed excellent adherence ability to the female genital epithelium, and had high lactic acid and H2O2 production capacity. Furthermore, it was found that HY7801 can alleviate BV because it can suppress the expression of virulence factor genes of GV involved in epithelial cell adhesion and biofilm formation along with antibacterial activity against GV. These results indicate that HY7801 can be used as a promising probiotic strain for the maintenance of a healthy vaginal physiological state.<br><br>SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-022-01208-7.}, }
@article {pmid36910511, year = {2023}, author = {Fleeman, RM and Mikesh, M and Davies, BW}, title = {Investigating Klebsiella pneumoniae biofilm preservation for scanning electron microscopy.}, journal = {Access microbiology}, volume = {5}, number = {2}, pages = {}, pmid = {36910511}, issn = {2516-8290}, abstract = {Klebsiella pneumoniae biofilm formation is associated with chronic and relapsing infections. Scanning electron microscopy (SEM) is a powerful tool for characterizing biofilm structure and studying their formation. Reliable visualization of biofilm structure requires careful sample preservation, otherwise there may be loss of non-covalent interactions that are susceptible to damage during the dehydration and washing preparation steps. However, no standard procedure has been adopted in the literature to fix K. pneumoniae biofilm for scanning electron microscopy studies. This lack of standardization makes it challenging to compare results between studies and determine the degree to which native structures have been preserved. To advance this critical area of study, we investigated different scanning electron microscopy fixation methods for K. pneumoniae biofilm preservation. Our study reveals the impact preparation steps can have on retaining in biofilm architecture observed using scanning electron microscopy. Using fixation methods developed through our studies, we show that although species that overproduce capsular extracellular polysaccharides produced more robust biofilms, K. pneumoniae can form a developed biofilm in the absence of capsular polysaccharides.}, }
@article {pmid36910230, year = {2023}, author = {Mirzaei, R and Esmaeili Gouvarchin Ghaleh, H and Ranjbar, R}, title = {Antibiofilm effect of melittin alone and in combination with conventional antibiotics toward strong biofilm of MDR-MRSA and -Pseudomonas aeruginosa.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1030401}, pmid = {36910230}, issn = {1664-302X}, abstract = {INTRODUCTION: Multidrug-resistant (MDR) pathogens are being recognized as a critical threat to human health if they can form biofilm and, in this sense, biofilm-forming MDR-methicillin resistant Staphylococcus aureus (MRSA) and -Pseudomonas aeruginosa strains are a worse concern. Hence, a growing body of documents has introduced antimicrobial peptides (AMPs) as a substitute candidate for conventional antimicrobial agents against drug-resistant and biofilm-associated infections. We evaluated melittin's antibacterial and antibiofilm activity alone and/or in combination with gentamicin, ciprofloxacin, rifampin, and vancomycin on biofilm-forming MDR-P. aeruginosa and MDR-MRSA strains.<br><br>METHODS: Antibacterial tests [antibiogram, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC)], anti-biofilm tests [minimum biofilm inhibition concentration (MBIC), and minimum biofilm eradication concentration (MBEC)], as well as synergistic antibiofilm activity of melittin and antibiotics, were performed. Besides, the influence of melittin alone on the biofilm encoding genes and the cytotoxicity and hemolytic effects of melittin were examined.<br><br>RESULTS: MIC, MBC, MBIC, and MBEC indices for melittin were in the range of 0.625-5, 1.25-10, 2.5-20, and 10-40 &#x3bc;g/ml, respectively. The findings found that the combination of melittin AMP with antibiotics was synergistic and fractional biofilm inhibitory concentration index (FBICi) for most tested concentrations was <0.5, resulting in a significant reduction in melittin, gentamicin, ciprofloxacin, vancomycin, and rifampin concentrations by 2-256.4, 2-128, 2-16, 4-64 and 4-8 folds, respectively. This phenomenon reduced the toxicity of melittin, whereby its synergist concentration required for biofilm inhibition did not show cytotoxicity and hemolytic activity. Our findings found that melittin decreased the expression of icaA in S. aureus and LasR in P. aeruginosa genes from 0.1 to 4.11 fold for icaA, and 0.11 to 3.7 fold for LasR, respectively.<br><br>CONCLUSION: Overall, the results obtained from our study show that melittin alone is effective against the strong biofilm of MDR pathogens and also offers sound synergistic effects with antibiotics without toxicity. Hence, combining melittin and antibiotics can be a potential candidate for further evaluation of in vivo infections by MDR pathogens.}, }
@article {pmid36909500, year = {2023}, author = {Cassin, EK and Araujo-Hernandez, SA and Baughn, DS and Londono, MC and Rodriguez, DQ and Tseng, BS}, title = {OprF impacts Pseudomonas aeruginosa biofilm matrix eDNA levels in a nutrient-dependent manner.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.03.01.530729}, pmid = {36909500}, abstract = {UNLABELLED: The biofilm matrix is composed of exopolysaccharides, eDNA, membrane vesicles, and proteins. While proteomic analyses have identified numerous matrix proteins, their functions in the biofilm remain understudied compared to the other biofilm components. In the Pseudomonas aeruginosa biofilm, several studies have identified OprF as an abundant matrix protein and, more specifically, as a component of biofilm membrane vesicles. OprF is a major outer membrane porin of P. aeruginosa cells. However, current data describing the effects of OprF in the P. aeruginosa biofilm is limited. Here we identify a nutrient-dependent effect of OprF in static biofilms, whereby Δ oprF cells form significantly less biofilm than wild type when grown in media containing glucose or low sodium chloride concentrations. Interestingly, this biofilm defect occurs during late static biofilm formation and is not dependent on the production of PQS, which is responsible for outer membrane vesicle production. Furthermore, while biofilms lacking OprF contain approximately 60% less total biomass than those of wild type, the number of cells in these two biofilms is equivalent. We demonstrate that P. aeruginosa Δ oprF biofilms with reduced biofilm biomass contain less eDNA than wild-type biofilms. These results suggest that the nutrient-dependent effect of OprF is involved in the maintenance of mature P. aeruginosa biofilms by retaining eDNA in the matrix.<br><br>IMPORTANCE: Many pathogens form biofilms, which are bacterial communities encased in an extracellular matrix that protects them against antibacterial treatments. The roles of several matrix components of the opportunistic pathogen Pseudomonas aeruginosa have been characterized. However, the effects of P. aeruginosa matrix proteins remain understudied and are untapped potential targets for antibiofilm treatments. Here we describe a conditional effect of the abundant matrix protein OprF on late-stage P. aeruginosa biofilms. A &#x394; oprF strain formed significantly less biofilm in low sodium chloride or with glucose. Interestingly, the defective &#x394; oprF biofilms did not exhibit fewer resident cells but contained significantly less extracellular DNA (eDNA) than wild type. These results suggest that OprF is involved in matrix eDNA retention in mature biofilms.}, }
@article {pmid36908866, year = {2023}, author = {Hamad, PA}, title = {Phenotypic and Molecular Detection of Biofilm Formation in Methicillin-Resistant Staphylococcus Aureus Isolated from Different Clinical Sources in Erbil City.}, journal = {Mediterranean journal of hematology and infectious diseases}, volume = {15}, number = {1}, pages = {e2023016}, pmid = {36908866}, issn = {2035-3006}, abstract = {BACKGROUND: Staphylococcus aureus is an important causative pathogen. The production of biofilms is an important factor and makes these bacteria resistant to antimicrobial therapy.<br><br>OBJECTIVES: the current study aimed to assess the prevalence of resistance to antibacterial agents and to evaluate the phenotypic and genotypic characterization of biofilm formation among S. aureus strains.<br><br>METHODS: This study included 50 isolates of Methicillin-resistant S. aureus (MRSA) and Methicillin-Susceptible S. aureus (MSSA). S. aureus was identified by molecular and conventional methods, and antimicrobial resistance was tested with a disc diffusion method. The biofilm formation was performed through the Microtiter plate method. Strains were subjected to PCR to determine the presence of nuc, mecA, icaA, icaB, icaC, and icaD genes.<br><br>RESULTS: Of the 50 S. aureus isolates, 32(64%) and 18(36%) were MRSA and MSSA, respectively. A large number of MRSA and MSSA isolates showed resistance to Penicillin and Azithromycin, and a lower number of MRSA and MSSA isolates showed resistance to Amikacin Gentamicin. None of the isolates was resistant to Vancomycin. The MRSA strains had significantly higher resistance against antibiotics than MSSA strains (P = 0.0154). All isolates (MRSA and MSSA) were able to produce biofilm with levels ranging from strong (31.25 %), (16.6%) to moderate (53.12%), (50%) to weak (15.6%), (33.3%) respectively. The MRSA strains had a significantly higher biofilm formation ability than the MSSA strains (P = 0.0079). The biofilm-encoding genes were detected among isolates with different frequencies. The majority of S. aureus isolates, 42 (84%), were positive for the icaA. The prevalence rates of the icaB, icaC and icaD genes were found to be 37 (74%), 40 (80%) and 41 (82%), respectively.<br><br>CONCLUSIONS: The prevalence of biofilm encoding genes associated with multidrug resistance in S. aureus strains is high. Therefore, identifying epidemiology, molecular characteristics, and biofilm management of S. aureus infection would be helpful.}, }
@article {pmid36907929, year = {2023}, author = {Maurya, A and Kumar, R and Raj, A}, title = {Biofilm-based technology for industrial wastewater treatment: current technology, applications and future perspectives.}, journal = {World journal of microbiology &amp; biotechnology}, volume = {39}, number = {5}, pages = {112}, pmid = {36907929}, issn = {1573-0972}, abstract = {The microbial community in biofilm is safeguarded from the action of toxic chemicals, antimicrobial compounds, and harsh/stressful environmental circumstances. Therefore, biofilm-based technology has nowadays become a successful alternative for treating industrial wastewater as compared to suspended growth-based technologies. In biofilm reactors, microbial cells are attached to static or free-moving materials to form a biofilm which facilitates the process of liquid and solid separation in biofilm-mediated operations. This paper aims to review the state-of-the-art of recent research on bacterial biofilm in industrial wastewater treatment including biofilm fundamentals, possible applications and problems, and factors to regulate biofilm formation. We discussed in detail the treatment efficiencies of fluidized bed biofilm reactor (FBBR), trickling filter reactor (TFR), rotating biological contactor (RBC), membrane biofilm reactor (MBfR), and moving bed biofilm reactor (MBBR) for different types of industrial wastewater treatment. Besides, biofilms have many applications in food and agriculture, biofuel and bioenergy production, power generation, and plastic degradation. Furthermore, key factors for regulating biofilm formation were also emphasized. In conclusion, industrial applications make evident that biofilm-based treatment technology is impactful for pollutant removal. Future research to address and improve the limitations of biofilm-based technology in wastewater treatment is also discussed.}, }
@article {pmid36907420, year = {2023}, author = {Zhuang, LL and Tian, W and Yang, Y and Ge, S and Li, P and Sun, S and Zhang, J and Liang, S}, title = {Quantified trend of photosynthetic rate along the depth of microalgae biofilm.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {162801}, doi = {10.1016/j.scitotenv.2023.162801}, pmid = {36907420}, issn = {1879-1026}, abstract = {Compared with suspended microalgae cultivation, attached microalgae cultivation for wastewater treatment has advantages of low biomass recovery costs and high robustness. As a heterogeneous system, the variation of photosynthetic capacity along biofilm depth lacks quantitative conclusions. The distribution curve of oxygen concentration along the depth of attached microalgae biofilm (f(x)) was detected by dissolved oxygen (DO) microelectrode, and a quantified model was built based on mass conservation and Fick's law. It revealed that the net photosynthetic rate at a certain depth (x) in the biofilm showed a linear relationship with the second derivatives of the distribution curve of oxygen concentration (f″(x)). In addition, the declining trend of photosynthetic rate of attached microalgae with depth was relatively slow compared with the suspended system. The net photosynthetic rate of algae biofilm decreased gradually with depth and was only 3.60 %-17.86 % of that of the surface layer at 150-200 μm depth. Moreover, the light saturation points of the attached microalgae got lower along the depth of biofilm. Compared to 400 lx light intensity, the net photosynthetic rate of microalgae biofilm at the depths of 100-150 μm and 150-200 μm increased by 389 % and 956 % under 5000 lx, respectively, showing the high photosynthesis potential with increasing light.}, }
@article {pmid36907360, year = {2023}, author = {Centeleghe, DI and Norville, DP and Hughes, DL and Maillard, PJ}, title = {Klebsiella pneumoniae survives on surfaces as a dry biofilm.}, journal = {American journal of infection control}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.ajic.2023.02.009}, pmid = {36907360}, issn = {1527-3296}, abstract = {BACKGROUND: Dry surface biofilms (DSB) are widespread in healthcare settings presenting a challenge to cleaning and disinfection. Klebsiella pneumoniae has been a focus of attention due to antibiotic resistance and the emergence of hypervirulent strains. Few studies have demonstrated K. pneumoniae survival on surfaces following desiccation.<br><br>METHODS: DSB were formed over 12 days. Bacterial culturability and transfer were investigated following DSB incubation up to four weeks. Bacterial viability in DSB was investigated with live/dead staining using flow cytometry.<br><br>RESULTS: K. pneumoniae formed mature DSB. After two and four weeks of incubation, transfer from DSB was low (<55%) and reduced further (<21%) following wiping. Culturability at two and four weeks varied although viability remained high indicating viable but non culturable state (VBNC).<br><br>DISCUSSION: K. pneumoniae was removed from surfaces by mechanical wiping as shown with DSB of other species. Although culturability was reduced over time, bacteria remained viable up to four weeks incubation, proving the need for robust cleaning regimens.<br><br>CONCLUSIONS: This is the first study confirming K. pneumoniae survival on dry surfaces as a DSB. The presence of VBNC bacteria indicated that K. pneumoniae can for extended periods, raising questions about its persistence on surfaces.}, }
@article {pmid36906314, year = {2023}, author = {Liu, J and Wu, S and Feng, L and Wu, Y and Zhu, J}, title = {Extracellular matrix affects mature biofilm and stress resistance of psychrotrophic spoilage Pseudomonas at cold temperature.}, journal = {Food microbiology}, volume = {112}, number = {}, pages = {104214}, doi = {10.1016/j.fm.2023.104214}, pmid = {36906314}, issn = {1095-9998}, abstract = {Psychrotrophic Pseudomonas as the dominant spoilage bacteria, have biofilm forming ability, increasing persistence and contamination in the chilled food. Biofilm formation of spoilage Pseudomonas at cold temperature was documented, however, role of extracellular matrix in mature biofilm and stress resistance of psychrotrophic Pseudomonas are much less abundant. The aim of this study was to investigate the biofilm forming characteristics of three spoilers P. fluorescens PF07, P. lundensis PL28, and P. psychrophile PP26 at 25 °C, 15 °C and 4 °C, and to explore their stress resistance to chemical and thermal treatments of mature biofilms. The results showed that biofilm biomass of three Pseudomonas at 4 °C was significantly higher than that at 15 °C and 25 °C. The secretion of extracellular polymeric substances (EPS) greatly increased in those Pseudomonas under low temperature, of which extracellular protein constituted about 71.03%-77.44%. Compared to 25 °C, the mature biofilms were observed to more aggregation and thicker spatial structure at 4 °C ranging from 42.7 to 54.6 μm, in contrast to 25.0-29.8 μm at 25 °C, especially strain PF07. These Pseudomonas biofilms switched into moderate hydrophobicity, and their swarming and swimming were significantly inhibited at low temperature. Furthermore, the resistance to NaClO and heating at 65 °C apparently enhanced for mature biofilm formed at 4 °C, indicating the difference in EPS matrix production influenced the stress resistance of biofilm. In addition, three strains contained alg and psl operons for exopolysaccharide biosynthesis, and biofilm related genes of algK, pslA, rpoS, and luxR were significantly up-regulated, while flgA gene was down-regulated at 4 °C compared to 25 °C, consistent with the above phenotype changes. Thus, the dramatic increase of mature biofilm and their stress resistance in psychrotrophic Pseudomonas were associated with large secretion and protection of extracellular matrix under low temperature, which provide a theoretical basis for subsequent biofilm control during cold chain.}, }
@article {pmid36906303, year = {2023}, author = {Zarei, M and Paknejad, M and Eskandari, MH}, title = {Sublethal chlorine stress promotes the biofilm-forming ability of Salmonella enterica serovars enteritidis and expression of the related genes.}, journal = {Food microbiology}, volume = {112}, number = {}, pages = {104232}, doi = {10.1016/j.fm.2023.104232}, pmid = {36906303}, issn = {1095-9998}, abstract = {Chlorine treatment is the most common disinfection method in food-related environments. In addition to being simple and inexpensive, this method is very effective if used properly. However, insufficient chlorine concentrations only cause a sublethal oxidative stress in the bacterial population and may alter the growth behavior of stressed cells. In the present study, the effect of sublethal chlorine stress on the biofilm formation characteristics of Salmonella Enteritidis was evaluated. Our results demonstrated that, sublethal chlorine stress (350 ppm total chlorine) activates the biofilm (csgD, agfA, adrA and bapA) and quorum-sensing (sdiA and luxS) related genes in planktonic cells of S. Enteritidis. The higher expression of these genes illustrated that the chlorine stress induced the initiation of the biofilm formation process in S. Enteritidis. Results of the initial attachment assay confirmed this finding. In addition, the number of chlorine-stressed biofilm cells was significantly higher than non-stressed biofilm cells after 48 h incubation at 37 °C. In S. Enteritidis ATCC 13076 and S. Enteritidis KL19, the number of chlorine-stressed biofilm cells were 6.93 ± 0.48 and 7.49 ± 0.57 log CFU/cm[2], while the number of non-stressed biofilm cells were 5.12 ± 0.39 and 5.63 ± 0.51 log CFU/cm[2], respectively. These findings were confirmed by measurements of the major components of biofilm, i.e., eDNA, protein and carbohydrate. The amount of these components in 48-h biofilms was higher when the cells were initially subjected to sublethal chlorine stress. However, the up-regulation of the biofilm and quorum sensing genes was not observed in 48-h biofilm cells, indicating that the effect of chlorine stress had vanished in the subsequent generations of Salmonella. In total, these results revealed that sublethal chlorine concentrations can promote the biofilm-forming ability of S Enteritidis.}, }
@article {pmid36905831, year = {2023}, author = {Guo, W and Li, Y and Wang, S and Wang, Y and Li, C and Jin, Y and Li, Y and Chen, X and Miao, W}, title = {Photodynamic nano hydroxyapatite with biofilm penetration capability for dental plaque eradication and prevention of demineralization.}, journal = {Colloids and surfaces. B, Biointerfaces}, volume = {225}, number = {}, pages = {113242}, doi = {10.1016/j.colsurfb.2023.113242}, pmid = {36905831}, issn = {1873-4367}, abstract = {Dental caries represents one of the most prevalent diseases worldwide, characteristic of the growth of dental plaque and demineralization of tooth enamel. Current medications for eradication of dental plaques and prevention of demineralization suffer from several limitations to overcome, calling for novel strategies with great potency in eliminating cariogenic bacteria and dental plaque that forms, as well as in inhibiting the demineralization of enamel, into an integrated system. Considering the potency of photodynamic therapy in bacteria inactivation and the composition of enamel, we herein report that the novel photodynamic nano hydroxyapatite (nHAP), named Ce6 @QCS/nHAP, was useful for this purpose. Ce6 @QCS/nHAP, comprised of quaternary chitosan (QCS)-coated nHAP loaded with chlorin e6 (Ce6), exhibited good biocompatibility and non-compromised photodynamic activity. In vitro studies revealed that Ce6 @QCS/nHAP could effectively associate with cariogenic Streptococcus mutans (S. mutans), leading to a significant antibacterial effect through photodynamic killing and physical inactivation against the planktonic microbe. Three-dimensional fluorescence imaging suggested that Ce6 @QCS/nHAP exhibited a superior S. mutans biofilm penetration capacity to free Ce6, resulting in effective dental plaque eradiation when light irradiation was applied. The number of surviving bacteria in biofilm was at least 2.8 log units lower in the Ce6 @QCS/nHAP group compared to that in the free Ce6 group. Further, in the S. mutans biofilm-infected artificial tooth model, treatment with Ce6 @QCS/nHAP also resulted in the significant prevention of hydroxyapatite disks from demineralization, with lower percentage of fragmentation and weight loss These data suggest that our photodynamic nanosystem can effectively eradicate dental plaque while also significantly protecting artificial tooth from demineralization, opening up new possibilities in treating bacterium-associated dental caries.}, }
@article {pmid36905317, year = {2023}, author = {Sharma, R and Johnson, RH and David, GR and Rahimifar, M and Heidari, A}, title = {A Case of Coccidioidal Meningitis With Biofilm Obstructing VP Shunt Due to Cutibacterium acnes.}, journal = {Journal of investigative medicine high impact case reports}, volume = {11}, number = {}, pages = {23247096231159810}, doi = {10.1177/23247096231159810}, pmid = {36905317}, issn = {2324-7096}, abstract = {Herein described is a case of biofilm obstructing ventriculoperitoneal shunt due to Cutibacteirum acnes infection in a patient with coccidioidal meningitis. Cutibacterium acnes infects and obstructs cerebral shunts by the production of biofilm; however, diagnosis is usually missed by routine aerobic cultures. Obtaining anaerobic cultures routinely in patients with foreign body implants leading to central nervous system infections could prevent a missed diagnosis of this pathogen. Penicillin G is the first-line treatment.}, }
@article {pmid36904487, year = {2023}, author = {Cremer, J and Kaltschmidt, BP and Kiel, A and Eberhard, J and Schmidt, S and Kaltschmidt, C and Kaltschmidt, B and Hütten, A and Anselmetti, D}, title = {Aging of Industrial Polypropylene Surfaces in Detergent Solution and Its Consequences for Biofilm Formation.}, journal = {Polymers}, volume = {15}, number = {5}, pages = {}, doi = {10.3390/polym15051247}, pmid = {36904487}, issn = {2073-4360}, abstract = {The performance of plastic components in water-bearing parts of industrial and household appliances, often in the presence of harsh environments and elevated temperatures, critically relies on the mechanical and thermal polymer stability. In this light, the precise knowledge of aging properties of polymers formulated with dedicated antiaging additive packages as well as various fillers is crucial for long-time device warranty. We investigated and analysed the time-dependent, polymer-liquid interface aging of different industrial performance polypropylene samples in aqueous detergent solution at high temperatures (95 °C). Special emphasis was put on the disadvantageous process of consecutive biofilm formation that often follows surface transformation and degradation. Atomic force microscopy, scanning electron microscopy, and infrared spectroscopy were used to monitor and analyse the surface aging process. Additionally, bacterial adhesion and biofilm formation was characterised by colony forming unit assays. One of the key findings is the observation of crystalline, fibre-like growth of ethylene bis stearamide (EBS) on the surface during the aging process. EBS is a widely used process aid and lubricant enabling the proper demoulding of injection moulding plastic parts. The aging-induced surface-covering EBS layers changed the surface morphology and promoted bacterial adhesion as well as biofilm formation of Pseudomonas aeruginosa.}, }
@article {pmid36904479, year = {2023}, author = {Mačák, L and Velgosova, O and Múdra, E and Vojtko, M and Dolinská, S}, title = {Transfer of AgNPs' Anti-Biofilm Activity into the Nontoxic Polymer Matrix.}, journal = {Polymers}, volume = {15}, number = {5}, pages = {}, doi = {10.3390/polym15051238}, pmid = {36904479}, issn = {2073-4360}, abstract = {A biological method was successfully applied to synthesize spherical silver nanoparticles (AgNPs) while using the extract of lavender (Ex-L) (lat. Lavandula angustifolia) as the reducing and stabilizing agent. The produced nanoparticles were spherical with an average size of 20 nm. The AgNPs' synthesis rate confirmed the extract's excellent ability to reduce silver nanoparticles from the AgNO3 solution. The presence of good stabilizing agents was confirmed by the excellent stability of the extract. Nanoparticles' shapes and sizes did not change. UV-Vis absorption spectrometry, Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were used to characterize the silver nanoparticles. The silver nanoparticles were incorporated into the PVA polymer matrix by the "ex situ" method. The polymer matrix composite with AgNPs was prepared in two ways: as a composite film and nanofibers (nonwoven textile). The anti-biofilm activity of AgNPs and the ability of AgNPs to transfer toxic properties into the polymer matrix were proved.}, }
@article {pmid36903742, year = {2023}, author = {Okamoto, K and Kudo, D and Phuong, DND and Iwamoto, Y and Watanabe, K and Yoshioka, Y and Ariyoshi, W and Yamasaki, R}, title = {Magnesium Hydroxide Nanoparticles Inhibit the Biofilm Formation of Cariogenic Microorganisms.}, journal = {Nanomaterials (Basel, Switzerland)}, volume = {13}, number = {5}, pages = {}, doi = {10.3390/nano13050864}, pmid = {36903742}, issn = {2079-4991}, abstract = {Although various caries-preventive agents have been developed, dental caries is still a leading global disease, mostly caused by biological factors such as mutans streptococci. Magnesium hydroxide nanoparticles have been reported to exhibit antibacterial effects; however, they are rarely used in oral care practical applications. In this study, we examined the inhibitory effect of magnesium hydroxide nanoparticles on biofilm formation by Streptococcus mutans and Streptococcus sobrinus-two typical caries-causing bacteria. Three different sizes of magnesium hydroxide nanoparticles (NM80, NM300, and NM700) were studied, all of which inhibited biofilm formation. The results showed that the nanoparticles were important for the inhibitory effect, which was not influenced by pH or the presence of magnesium ions. We also determined that the inhibition process was mainly contact inhibition and that medium (NM300) and large (NM700) sizes were particularly effective in this regard. The findings of our study demonstrate the potential applications of magnesium hydroxide nanoparticles as caries-preventive agents.}, }
@article {pmid36903577, year = {2023}, author = {Tran, HQ and Alam, H and Goff, A and Daeneke, T and Bhave, M and Yu, A}, title = {Multifunctional Fe3O4 Nanoparticles Filled Polydopamine Hollow Rods for Antibacterial Biofilm Treatment.}, journal = {Molecules (Basel, Switzerland)}, volume = {28}, number = {5}, pages = {}, doi = {10.3390/molecules28052325}, pmid = {36903577}, issn = {1420-3049}, abstract = {This work reports the use of mesoporous silica rods as templates for the step-wise preparation of multifunctional Fe3O4 NPs filled polydopamine hollow rods (Fe3O4@PDA HR). The capacity of as-synthesized Fe3O4@PDA HR as a new drug carrier platform was assessed by its loading and the triggered release of fosfomycin under various stimulations. It was found that the release of fosfomycin was pH dependent with ~89% of fosfomycin being released in pH 5 after 24 h, which was 2-fold higher than that in pH 7. The magnetic properties of Fe3O4 NPs and the photothermal properties of PDA enabled the triggered release of fosfomycin upon the exposure to rotational magnetic field, or NIR laser irradiation. Additionally, the capability of using multifunctional Fe3O4@PDA HR to eliminate preformed bacterial biofilm was demonstrated. Upon exposure to the rotational magnetic field, the biomass of a preformed biofilm was significantly reduced by 65.3% after a 20 min treatment with Fe3O4@PDA HR. Again, due to the excellent photothermal properties of PDA, a dramatic biomass decline (72.5%) was achieved after 10 min of laser exposure. This study offers an alternative approach of using drug carrier platform as a physical mean to kill pathogenic bacteria along with its traditional use for drug delivery.}, }
@article {pmid36903518, year = {2023}, author = {Zhang, Z and Zhao, Y and Cai, J and Wang, T and Song, Y and Lu, J and Du, H and Wang, W and Zhao, Y and Guo, L}, title = {Optimized Extraction, Identification and Anti-Biofilm Action of Wu Wei Zi (Fructus Schisandrae Chinensis) Extracts against Vibrio parahaemolyticus.}, journal = {Molecules (Basel, Switzerland)}, volume = {28}, number = {5}, pages = {}, doi = {10.3390/molecules28052268}, pmid = {36903518}, issn = {1420-3049}, abstract = {The pathogenicity of foodborne Vibrio parahaemolyticus is a major concern for global public health. This study aimed to optimize the liquid-solid extraction of Wu Wei Zi extracts (WWZE) against Vibrio parahaemolyticus, identify its main components, and investigate the anti-biofilm action. The extraction conditions optimized by the single-factor test and response surface methodology were ethanol concentration of 69%, temperature at 91 °C, time of 143 min, and liquid-solid ratio of 20:1 mL/g. After high performance liquid chromatography (HPLC) analysis, it was found that the main active ingredients of WWZE were schisandrol A, schisandrol B, schisantherin A, schisanhenol, and schisandrin A-C. The minimum inhibitory concentration (MIC) of WWZE, schisantherin A, and schisandrol B measured by broth microdilution assay was 1.25, 0.625, and 1.25 mg/mL, respectively, while the MIC of the other five compounds was higher than 2.5 mg/mL, indicating that schisantherin A and schizandrol B were the main antibacterial components of WWZE. Crystal violet, Coomassie brilliant blue, Congo red plate, spectrophotometry, and Cell Counting Kit-8 (CCK-8) assays were used to evaluate the effect of WWZE on the biofilm of V. parahaemolyticus. The results showed that WWZE could exert its dose-dependent potential to effectively inhibit the formation of V. parahaemolyticus biofilm and clear mature biofilm by significantly destroying the cell membrane integrity of V. parahaemolyticus, inhibiting the synthesis of intercellular polysaccharide adhesin (PIA), extracellular DNA secretion, and reducing the metabolic activity of biofilm. This study reported for the first time the favorable anti-biofilm effect of WWZE against V. parahaemolyticus, which provides a basis for deepening the application of WWZE in the preservation of aquatic products.}, }
@article {pmid36902594, year = {2023}, author = {Popov, G and Aleksandrov, R and Petkova, V and Kaneva, R and Gergova, R and Kundurzhiev, T and Popova, D}, title = {Analysis of Bacterial Biofilm Formation and MUC5AC and MUC5B Expression in Chronic Rhinosinusitis Patients.}, journal = {Journal of clinical medicine}, volume = {12}, number = {5}, pages = {}, doi = {10.3390/jcm12051808}, pmid = {36902594}, issn = {2077-0383}, abstract = {Chronic rhinosinusitis (CRS) is a condition affecting as much as 16% of the adult population in developed countries with many factors attributed to its development, including the more recently proposed role of bacterial biofilm infections. Plenty of research has been conducted on biofilms in CRS and the causes behind the development of such an infection in the nasal cavity and sinuses. One such probable cause is the production of mucin glycoproteins by the mucosa of the nasal cavity. To investigate the possible link between biofilm formation and mucin expression levels and their relationship with CRS etiology, we examined samples from 85 patients by means of spinning disk confocal microscopy (SDCM) to establish their biofilm status and quantitative reverse transcription polymerase chain reaction (qRT-PCR) to determine MUC5AC and MUC5B expression levels. We observed a significantly higher prevalence of bacterial biofilms in the CRS patient group compared to the control group. In addition, we detected higher expression levels of MUC5B but not MUC5AC in the CRS group, which suggested a possible role for MUC5B in CRS development. Finally, we found no direct relationship between biofilm presence and mucin expression levels, thereby showing a multifaceted connection between these two major factors implicated in CRS etiology.}, }
@article {pmid36902413, year = {2023}, author = {Parvin, F and Rahman, MA and Deva, AK and Vickery, K and Hu, H}, title = {Staphylococcus aureus Cell Wall Phenotypic Changes Associated with Biofilm Maturation and Water Availability: A Key Contributing Factor for Chlorine Resistance.}, journal = {International journal of molecular sciences}, volume = {24}, number = {5}, pages = {}, doi = {10.3390/ijms24054983}, pmid = {36902413}, issn = {1422-0067}, abstract = {Staphylococcus aureus biofilms are resistant to both antibiotics and disinfectants. As Staphylococci cell walls are an important defence mechanism, we sought to examine changes to the bacterial cell wall under different growth conditions. Cell walls of S. aureus grown as 3-day hydrated biofilm, 12-day hydrated biofilm, and 12-day dry surface biofilm (DSB) were compared to cell walls of planktonic organisms. Additionally, proteomic analysis using high-throughput tandem mass tag-based mass spectrometry was performed. Proteins involved in cell wall synthesis in biofilms were upregulated in comparison to planktonic growth. Bacterial cell wall width (measured by transmission electron microscopy) and peptidoglycan production (detected using a silkworm larva plasma system) increased with biofilm culture duration (p < 0.001) and dehydration (p = 0.002). Similarly, disinfectant tolerance was greatest in DSB, followed by 12-day hydrated biofilm and then 3-day biofilm, and it was least in the planktonic bacteria--suggesting that changes to the cell wall may be a key factor for S. aureus biofilm biocide resistance. Our findings shed light on possible new targets to combat biofilm-related infections and hospital dry surface biofilms.}, }
@article {pmid36902169, year = {2023}, author = {Charęza, M and Przygrodzka, K and Żywicka, A and Grygorcewicz, B and Sobolewski, P and Mozia, S and Śmiglak, M and Drozd, R}, title = {Enhancement of Inhibition of the Pseudomonas sp. Biofilm Formation on Bacterial Cellulose-Based Wound Dressing by the Combined Action of Alginate Lyase and Gentamicin.}, journal = {International journal of molecular sciences}, volume = {24}, number = {5}, pages = {}, doi = {10.3390/ijms24054740}, pmid = {36902169}, issn = {1422-0067}, abstract = {Bacterial biofilms generally contribute to chronic infections, including wound infections. Due to the antibiotic resistance mechanisms protecting bacteria living in the biofilm, they are a serious problem in the wound healing process. To accelerate the wound healing process and avoid bacterial infection, it is necessary to select the appropriate dressing material. In this study, the promising therapeutic properties of alginate lyase (AlgL) immobilised on BC membranes for protecting wounds from Pseudomonas aeruginosa infection were investigated. The AlgL was immobilised on never dried BC pellicles via physical adsorption. The maximum adsorption capacity of AlgL was 6.0 mg/g of dry BC, and the equilibrium was reached after 2 h. The adsorption kinetics was studied, and it has been proven that the adsorption was consistent with Langmuir isotherm. In addition, the impact of enzyme immobilisation on bacterial biofilm stability and the effect of simultaneous immobilisation of AlgL and gentamicin on the viability of bacterial cells was investigated. The obtained results showed that the AlgL immobilisation significantly reduced the amount of polysaccharides component of the P. aeruginosa biofilm. Moreover, the biofilm disruption by AlgL immobilised on BC membranes exhibited synergism with the gentamicin, resulting in 86.5% more dead P. aeruginosa PAO-1 cells.}, }
@article {pmid36900736, year = {2023}, author = {Saengphen, T and Koontongkaew, S and Utispan, K}, title = {Effectiveness of a Combined Toothbrushing Technique on Cariogenic Dental Biofilm in Relation to Stainless Steel and Elastomeric Ligatures in Orthodontic Patients: A Randomized Clinical Trial.}, journal = {Healthcare (Basel, Switzerland)}, volume = {11}, number = {5}, pages = {}, doi = {10.3390/healthcare11050731}, pmid = {36900736}, issn = {2227-9032}, abstract = {Increased dental biofilm commonly occurs during orthodontic treatment. The aim of this study was to evaluate the effect of a combined toothbrushing method on dental biofilm cariogenicity in patients with stainless steel (SSL) and elastomeric (EL) ligatures. At baseline (T1), 70 participants were randomized (1:1 ratio) to the SSL or EL group. Dental biofilm maturity was evaluated using a three-color-disclosing dye. The participants were instructed to brush their teeth using a combined horizontal-Charters-modified Bass technique. Dental biofilm maturity was reassessed at the 4-week follow-up (T2). We found that at T1, new dental biofilm was the highest, followed by mature and cariogenic dental biofilm in the SSL group (p < 0.05). In the EL group, cariogenic dental biofilm was highly observed, followed by mature and new dental biofilm (p < 0.05). After intervention, cariogenic dental biofilm significantly decreased in both groups (p < 0.05). Moreover, a marked decrease in cariogenic dental biofilm was observed in the EL group compared with the SSL group (p < 0.05). However, the change in mature dental biofilm in the groups was similar (p > 0.05). Our results demonstrated that the combined toothbrushing method reduced cariogenic dental biofilm in the SSL and EL groups.}, }
@article {pmid36898963, year = {2023}, author = {Budil, J and StenclovÃ, P and Kromka, A and LiÅ kovÃ, P}, title = {Development of the Pseudomonas syringae Pathovar morsprunorum Biofilm Monitored in Real-Time Using Attenuated Total Reflection Fourier Transform Infrared Measurements in a Flow Cell Chamber.}, journal = {Applied spectroscopy}, volume = {}, number = {}, pages = {37028231165057}, doi = {10.1177/00037028231165057}, pmid = {36898963}, issn = {1943-3530}, abstract = {Biofilms of sessile Pseudomonas syringae cells formed on top of plant host's leaves or fruits allow surviving harsh environmental conditions (desiccation) and improve their resistance to antibacterial treatments of crops. Better understanding of these biofilms can help minimize their effect on harvests. In the present study, infrared attenuated total reflection (IR-ATR) spectroscopy with optical and confocal laser scanning microscopy have been applied to analyze Pseudomonas syringae pathovar morsprunorum biofilm development in real-time, for the first time. The biofilm development was observed within the spectral window 4000-800 cm[-1] at constant flow conditions during 72 h. The kinetics of representative integrated band areas (nucleic acids with polysaccharides at 1141-1006 cm[-1], amino acid side chains with free fatty acids at 1420-1380 cm[-1], proteins at 1580-1490 cm[-1], and lipids with proteins at 2935-2915 cm[-1]) were analyzed with regards to the observed biofilm structure and following P. syringae biofilm developmental stages were attributed: The inoculation phase, washing of weakly attached bacteria closely followed by recolonization of vacated surface, the restructuration phase, and finally the maturation phase.}, }
@article {pmid36898591, year = {2023}, author = {Ragupathi, NKD and Muthuirulandi Sethuvel, DP and Gopikrishnan, M and Dwarakanathan, HT and Murugan, D and Biswas, I and Bakthavachalam, YD and Murugesan, M and George Priya Doss, C and Monk, PN and Karunakaran, E and Veeraraghavan, B}, title = {Phage-based therapy against biofilm producers in gram-negative ESKAPE pathogens.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106064}, doi = {10.1016/j.micpath.2023.106064}, pmid = {36898591}, issn = {1096-1208}, abstract = {Persistent antibiotic use results in the rise of antimicrobial resistance with limited or no choice for multidrug-resistant (MDR) and extensively drug resistant (XDR) bacteria. This necessitates a need for alternative therapy to effectively combat clinical pathogens that are resistant to last resort antibiotics. The study investigates hospital sewage as a potential source of bacteriophages to control resistant bacterial pathogens. Eighty-one samples were screened for phages against selected clinical pathogens. Totally, 10 phages were isolated against A. baumannii, 5 phages against K. pneumoniae, and 16 phages were obtained against P. aeruginosa. The novel phages were observed to be strain-specific with complete bacterial growth inhibition of up to 6 h as monotherapy without antibiotics. Phage plus colistin combinations reduced the minimum-biofilm eradication concentration of colistin up to 16 folds. Notably, a cocktail of phages exhibited maximum efficacy with complete killing at 0.5-1 μg/ml colistin concentrations. Thus, phages specific to clinical strains have a higher edge in treating nosocomial pathogens with their proven anti-biofilm efficacy. In addition, analysis of phage genomes revealed close phylogenetic relations with phages reported from Europe, China, and other neighbouring countries. This study serves as a reference and can be extended to other antibiotics and phage types to assess optimum synergistic combinations to combat various drug resistant pathogens in the ongoing AMR crisis.}, }
@article {pmid36897105, year = {2023}, author = {Halder, M and Narula, M and Singh, Y}, title = {Supramolecular, Nanostructured Assembly of Antioxidant and Antibacterial Peptides Conjugated to Naproxen and Indomethacin for the Selective Inhibition of COX-2, Biofilm, and Inflammation in Chronic Wounds.}, journal = {Bioconjugate chemistry}, volume = {}, number = {}, pages = {}, doi = {10.1021/acs.bioconjchem.3c00014}, pmid = {36897105}, issn = {1520-4812}, abstract = {Chronic wounds are a major healthcare challenge around the world. The presence of bacterial biofilms, accumulation of reactive oxygen species (ROS), and persistent inflammation have been identified as rate-limiting steps in chronic wound healing. Anti-inflammatory drugs, like naproxen (Npx) and indomethacin (Ind), show poor selectivity for the COX-2 enzyme, which plays a key role in producing inflammatory responses. To address these challenges, we have developed conjugates of Npx and Ind with peptides possessing antibacterial, antibiofilm, and antioxidant properties along with enhanced selectivity for the COX-2 enzyme. We have synthesized and characterized peptide conjugates Npx-YYk, Npx-YYr, Ind-YYk, and Ind-YYr, which were self-assembled into supramolecular gels. As envisaged, the conjugates and gels showed high proteolytic stability and selectivity toward the COX-2 enzyme and potent antibacterial activities (>95% within 12 h) against Gram-positive bacteria Staphylococcus aureus, implicated in wound-related infections, eradication of biofilm (∼80%), and radical scavenging (>90%) properties. Cell culture studies with mouse fibroblast cells (L929) and macrophage-like cells (RAW 264.7) showed that gels were cell proliferative in nature (120% viability), which resulted in faster and more efficient scratch healing. Treatment with gels led to a significant decrease in proinflammatory cytokine (TNF-α and IL-6) expressions and an increase in anti-inflammatory gene (IL-10) expression. The gels developed in this work show great promise as a topical agent for chronic wounds or as a coating for medical devices to prevent medical-device-associated infections.}, }
@article {pmid36894813, year = {2023}, author = {Kalashnikova, TV and Sutormina, LV and Samoilova, ZY and Oktyabrsky, ON and Smirnova, GV}, title = {Effect of Changes in the Redox Status on Biofilm Formation in Escherichia coli.}, journal = {Bulletin of experimental biology and medicine}, volume = {}, number = {}, pages = {}, pmid = {36894813}, issn = {1573-8221}, abstract = {Changes in the redox balance in the medium and in Escherichia coli cells significantly affect the ability of bacteria to form biofilms. An increase in the level of aeration in the culture of wild-type bacteria led to a 3-fold decrease in the mass of biofilms. Mutants lacking components of the glutathione and thioredoxin redox systems, as well as transporters involved in the transmembrane cycling of glutathione, demonstrated increased biofilm formation ability. The effect of exogenous glutathione on biofilm formation depended on the culturing conditions. The addition of 0.1-1 mM Trolox (a water-soluble analog of vitamin E) was accompanied by a 30-40% reduction in biofilm formation.}, }
@article {pmid36893978, year = {2023}, author = {Abdelhak, S and Menard, Y and Artigas, J}, title = {Effects of global change on the ability of stream biofilm to dissipate the herbicide glyphosate.}, journal = {Environmental pollution (Barking, Essex : 1987)}, volume = {324}, number = {}, pages = {121406}, doi = {10.1016/j.envpol.2023.121406}, pmid = {36893978}, issn = {1873-6424}, abstract = {The herbicide glyphosate is contaminating a large number of freshwater ecosystems worldwide and its fate and effects remains uncertain in light of the effects of global change. The present study examines how variations in water temperature and light availability relative to global change affect the ability of stream biofilms to degrade the herbicide glyphosate. Biofilms were exposed in microcosms to two levels of water temperature simulating global warming (Ambient = 19-22 °C and Warm = 21-24 °C) and three levels of light representative of riparian habitat destruction due to land use change (Dark = 0, Intermediate = 600, High = 1200 μmol photons m[-2] s[-1]). Biofilms were acclimated to six different experimental treatments, namely i) ambient temperature without light (AMB_D), ii) ambient temperature and intermediate light (AMB_IL), iii) ambient temperature and high light (AMB_HL), iv) warm temperature without light (WARM_D), v) warm temperature and intermediate light (WARM_IL) and vi) warm temperature and high light (WARM_HL). The ability of biofilms to degrade 50 μg L[-1] of glyphosate was tested. Results showed that water temperature increase, but not light availability increase, significantly increased aminomethyl phosphonic acid (AMPA) production by biofilms. However, the combined increase of temperature and light generated the shortest time to dissipate half of the glyphosate supplied and/or half of the maximum AMPA produced (6.4 and 5.4 days, respectively) by biofilms. Despite light had a major effect in modulating biofilm structural and functional descriptors, the response of certain descriptors (i. e. chlorophyll-a concentration, bacterial density and diversity, nutrient content and PHO activity) to light availability increase depended on water temperature. Specifically, the biofilms in the WARM_HL treatment displayed the highest Glucosidase: Peptidase and Glucosidase: Phosphatase enzyme activity ratios and the lowest biomass C: N molar ratios compared to the other treatments. According to these results, warmer temperatures and high light availability could have been exacerbating the decomposition of organic C compounds in biofilms, including the use of glyphosate as a C source for microbial heterotrophs. This study shows that ecoenzymatic stoichiometry and xenobiotic biodegradation approaches can be combined to better understand the functioning of biofilms in pesticide-polluted streams.}, }
@article {pmid36893665, year = {2023}, author = {Meng, X and Xiong, H and Ji, F and Gao, X and Han, L and Wu, Z and Jia, L and Ren, J}, title = {Facile surface treatment strategy to generate dense lysozyme layer on ultra-high molecular weight polyethylene enabling inhibition of bacterial biofilm formation.}, journal = {Colloids and surfaces. B, Biointerfaces}, volume = {225}, number = {}, pages = {113243}, doi = {10.1016/j.colsurfb.2023.113243}, pmid = {36893665}, issn = {1873-4367}, abstract = {Medical plastics such as those found in endotracheal tubes are widely used in intensive care units for the treatment of critically ill patients. Although commonplace in hospital environment, these catheters are at a high risk of bacterial contamination and have been found responsible for numerous health-care-associated infections. Antimicrobial coatings that can prevent harmful bacterial growth are required to reduce the occurrence of such infections. In this study, we introduce a facile surface treatment strategy that could form antimicrobial coatings on the surface of average medical plastics. The strategy involves treatment of activated surfaces with lysozyme, a natural antimicrobial enzyme presenting in human lacrimal gland secretions which is widely used for wound healing. Using ultra-high molecular weight polyethylene (UHMWPE) as the representative surface, oxygen/argon plasma treatment for 3 min led to the increase of surface roughness and the generation of negatively charged groups, with the zeta potential measured as -94.5 mV at pH 7. The activated surface could accommodate lysozyme with a density of up to 0.3 nmol/cm[2] through electrostatic interaction. Antimicrobial activity of the resulting surface (UHMWPE@Lyz) was characterized with Escherichia coli and Pseudomonas sp. strains, and the treated surface significantly inhibited the bacterial colonization and the formation of biofilm compared to the untreated UHMWPE. This method of constructing an effective lysozyme-based antimicrobial coating is a generally applicable, simple and fast process for surface treatment with no adverse solvent and wastes involved.}, }
@article {pmid36893426, year = {2023}, author = {Li, X and Kong, R and Wang, J and Wu, J and He, K and Wang, X}, title = {The formation mechanism of Bacillus subtilis biofilm surface morphology under competitive environment.}, journal = {Canadian journal of microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1139/cjm-2023-0014}, pmid = {36893426}, issn = {1480-3275}, abstract = {Material properties and growth environments affect the surface morphology of biofilms. Taken the biofilm growing in competitive environments as the object, which is compared with the single biofilm, we find that the competitive environment has an impact on the biofilm thickness and wrinkle pattens. Through Diffusion Limited Growth (DLG) theoretical model analysis, it shows that the competitive environment is caused by cell competing for nutrition, and the competitive environment reacts on biofilm which affect the phenotypic differentiation, causing changes in the stiffness of the biofilm. Using the theoretical and finite element simulation, we compare these results of bi-layer and tri-layer film-substrate models with experimental observations, and find that tri-layer film-substrate model is in line with the reality, which means that the layer between the biofilm and substrate plays an import role for wrinkle formation. Based on the above analysis, we further study effects of biofilm stiffness and interlayer thickness on wrinkles under competitive environment.}, }
@article {pmid36890534, year = {2023}, author = {Zhu, M and Dang, J and Dong, F and Zhong, R and Zhang, J and Pan, J and Li, Y}, title = {Antimicrobial and cleaning effects of ultrasonic-mediated plasma-loaded microbubbles on Enterococcus faecalis biofilm: an in vitro study.}, journal = {BMC oral health}, volume = {23}, number = {1}, pages = {133}, pmid = {36890534}, issn = {1472-6831}, mesh = {Humans ; *Enterococcus faecalis ; Hydrogen Peroxide/pharmacology ; Ultrasonics ; Microbubbles ; Root Canal Irrigants/pharmacology ; *Anti-Infective Agents/pharmacology ; Biofilms ; Sodium Hypochlorite/pharmacology ; Dental Pulp Cavity ; Dentin ; Microscopy, Confocal ; }, abstract = {BACKGROUND: Enterococcus faecalis (E. faecalis) is the most frequently isolated bacteria from teeth with root canal treatment failure. This study aims to evaluate the disinfection effect of ultrasonic-mediated cold plasma-loaded microbubbles (PMBs) on 7d E. faecalis biofilm, the mechanical safety and the mechanisms.<br><br>METHODS: The PMBs were fabricated by a modified emulsification process and the key reactive species, nitric oxide (NO) and hydrogen peroxide (H2O2) were evaluated. The 7d E. faecalis biofilm on human tooth disk was constructed and divided into the following groups: PBS, 2.5%NaOCl, 2%CHX, and different concentrations of PMBs (10[8]&#xa0;mL[-1], 10[7]&#xa0;mL[-1]). The disinfection effects and elimination effects were verified with confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Microhardness and roughness change of dentin after PMBs treatment were verified respectively.<br><br>RESULTS: The concentration of NO and H2O2 in PMBs increased by 39.99% and 50.97% after ultrasound treatment (p&#x2009;<&#x2009;0.05) respectively. The CLSM and SEM results indicate that PMBs with ultrasound treatment could remove the bacteria and biofilm components effectively, especially those living in dentin tubules. The 2.5% NaOCl presented an excellent effect against biofilm on dishes, but the elimination effect on dentin tubules is limited. The 2% CHX group exhibits significant disinfection effect. The biosafety tests indicated that there is no significant changes on microhardness and roughness after PMBs with ultrasound treatment (p&#x2009;>&#x2009;0.05).<br><br>CONCLUSION: PMBs combined with ultrasound treatment exhibited significant disinfection effect and biofilm removal effect, the mechanical safety is acceptable.}, }
@article {pmid36890147, year = {2023}, author = {Maknuna, L and Tran, VN and Lee, BI and Kang, HW}, title = {Inhibitory effect of 405 nm laser light on bacterial biofilm in urethral stent.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {3908}, pmid = {36890147}, issn = {2045-2322}, abstract = {The clinical use of urethral stents is usually complicated by various adverse effects, including dysuria, fever, and urinary tract infection (UTI). Biofilms (formed by bacteria, such as Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus) adhering to the stent cause UTIs in stented patients (approximately 11%). The undesirable consequences of antibiotics use include bacterial resistance, weight gain, and type 1 diabetes, which occur when antibiotics are used for a long time. We aimed to assess the efficacy of a new optical treatment with a 405 nm laser to inhibit bacterial growth in a urethral stent in vitro. The urethral stent was grown in S. aureus broth media for three days to induce biofilm formation under dynamic conditions. Various irradiation times with the 405 nm laser light were tested (5, 10, and 15 min). The efficacy of the optical treatment on biofilms was evaluated quantitatively and qualitatively. The production of reactive oxygen species helped eliminate the biofilm over the urethral stent after 405 nm irradiation. The inhibition rate corresponded to a 2.2 log reduction of colony-forming units/mL of bacteria after 0.3 W/cm[2] of irradiation for 10 min. The treated stent showed a significant reduction in biofilm formation compared with the untreated stent, as demonstrated by SYTO 9 and propidium iodide staining. MTT assays using the CCD-986sk cell line revealed no toxicity after 10 min of irradiation. We conclude that optical treatment with 405 nm laser light inhibits bacterial growth in urethral stents with no or minimal toxicity.}, }
@article {pmid36889408, year = {2023}, author = {Feng, L and Sun, FY and Yang, J and Cui, D and Li, ZH and Pi, S and Zhao, HP and Li, A}, title = {Intracellular electron competition in response to the oxygen pressure of the aerobic denitrification process in an O2-based membrane biofilm reactor (MBfR) for nitrate removal.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {162592}, doi = {10.1016/j.scitotenv.2023.162592}, pmid = {36889408}, issn = {1879-1026}, abstract = {This study quantitatively investigated the effect of dissolved oxygen (DO) concentration on aerobic denitrification, and showed the mechanism of aerobic denitrification from the perspective of electron competition by cultivating Pseudomonas stutzeri T13, a typical aerobic denitrifier, in an oxygen-based membrane biofilm reactor (O2-based MBfR). The experiments showed that when the O2 pressure increased from 2 to 10 psig (psig), the averaged effluent DO during steady-state phases increased from 0.02 to 4.23 mg/L, and the corresponding mean NO3[-]-N removal efficiency slightly decreased from 97.2 % to 90.9 %. Compared to the maximum theoretical flux of O2 in various phases, the actual O2 transfer flux increased from a limited status (2.07 e[-] eq m[-2] d[-1] at 2 psig) to an excessive status (5.58 e[-] eq m[-2] d[-1] at 10 psig). The increase of DO inhibited the electron availability for aerobic denitrification, which decreased from 23.97 % to 11.46 %, accompanying the increased electron availability for aerobic respiration from 15.87 % to 28.36 %. Unlike the napA and norB genes, the expression of the nirS and nosZ genes was significantly affected by DO, with the highest relative fold-changes of 6.5 and 6.13 at 4 psig O2, respectively. The results contribute to clarifying the mechanism of aerobic denitrification either from quantitative perspective of electron distribution and qualitative perspective of gene expression, which benefits the regulation and practical application of aerobic denitrification for wastewater treatment.}, }
@article {pmid36889402, year = {2023}, author = {Afonso, AC and Gomes, IB and Saavedra, MJ and Simões, L and Simões, M}, title = {Drinking-water isolated Delftia acidovorans selectively coaggregates with partner bacteria and facilitates multispecies biofilm development.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {162646}, doi = {10.1016/j.scitotenv.2023.162646}, pmid = {36889402}, issn = {1879-1026}, abstract = {Coaggregation plays an important role in the development of multispecies biofilms in different environments, often serving as an active bridge between biofilm members and other organisms that, in their absence, would not integrate the sessile structure. The ability of bacteria to coaggregate has been reported for a limited number of species and strains. In this study, 38 bacterial strains isolated from drinking water (DW) were investigated for their ability to coaggregate, in a total of 115 pairs of combinations. Among these isolates, only Delftia acidovorans (strain 005P) showed coaggregating ability. Coaggregation inhibition studies have shown that the interactions mediating D. acidovorans 005P coaggregation were both polysaccharide-protein and protein-protein, depending on the interacting partner bacteria. Dual-species biofilms of D. acidovorans 005P and other DW bacteria were developed to understand the role of coaggregation on biofilm formation. Biofilm formation by Citrobacter freundii and Pseudomonas putida strains highly benefited from the presence of D. acidovorans 005P, apparently due to the production of extracellular molecules/public goods favouring microbial cooperation. This was the first time that the coaggregation capacity of D. acidovorans was demonstrated, highlighting its role in providing a metabolic opportunity for partner bacteria.}, }
@article {pmid36888841, year = {2023}, author = {Santos, VCED and Maquera-Huacho, PM and Imbriani, MJM and Minhaco, VMTR and Spolidorio, DMP}, title = {Effects of BlueM® against Streptococcus mutans biofilm and its virulence gene expression.}, journal = {Brazilian dental journal}, volume = {34}, number = {1}, pages = {19-28}, doi = {10.1590/0103-6440202305133}, pmid = {36888841}, issn = {1806-4760}, abstract = {This study evaluated the antimicrobial capacity of BlueM® mouthwash against the bacterium Streptococcus mutans and its influence on gbpA gene expression as well as its cytotoxic effect on fibroblast cells. BlueM® showed antimicrobial activity, with MIC and MBC values of 0.005% and 0.01%, respectively. The MBIC was 6.25% for S. mutans. CFU count and confocal microscopy revealed significant effect of BlueM® on S. mutans biofilm pre-formed on dentin surfaces. Interestingly, the analysis of gbpA gene expression indicated a decrease in gene expression after 15 min of treatment with BlueM® at a concentration of 25%. Moreover, BlueM® exhibited low levels of cytotoxicity. In conclusion, our results showed the antimicrobial effectiveness of BlueM® against S. mutans, its ability to modulate the expression of the gbpA gene and its low cytotoxicity. This study supports the therapeutic potential of BlueM® as an alternative agent for the control of oral biofilm.}, }
@article {pmid36884153, year = {2023}, author = {Memar, MY and Yekani, M and Farajnia, S and Ghadiri Moghaddam, F and Nabizadeh, E and Sharifi, S and Maleki Dizaj, S}, title = {Antibacterial and biofilm-inhibitory effects of vancomycin-loaded mesoporous silica nanoparticles on methicillin-resistant staphylococcus aureus and gram-negative bacteria.}, journal = {Archives of microbiology}, volume = {205}, number = {4}, pages = {109}, pmid = {36884153}, issn = {1432-072X}, abstract = {The present study aimed to prepare and characterize vancomycin-loaded mesoporous silica nanoparticles (Van-MSNs) to detect inhibitory effects on the planktonic and biofilm forms of methicillin-resistant Staphylococcus aureus (MRSA) isolates, and study the biocompatibility and toxicity of Van-MSNs in vitro as well as antibacterial activity of Van-MSNs against Gram-negative bacteria. The inhibitory effects of Van-MSNs were investigated on MRSA using the determination of minimum inhibitory (MIC) and minimum biofilm-inhibitory concentrations (MBIC) as well as the effect on bacterial attachment. Biocompatibility was studied by examining the effect of Van-MSNs on the lysis and sedimentation rate of red blood cells (RBC). The interaction of Van-MSNs with human blood plasma was detected by the SDS-PAGE approach. The cytotoxic effect of the Van-MSNs on human bone marrow mesenchymal stem cells (hBM-MSCs) was evaluated by the MTT assay. The antibacterial effects of vancomycin and Van-MSNs on Gram-negative bacteria were also investigated using MIC determination using the broth microdilution method. Furthermore, bacteria outer membrane (OM) permeabilization was determined. Van-MSNs showed inhibitory effects on planktonic and biofilm forms of bacteria on all isolates at levels lower than MICs and MBICs of free vancomycin, but the antibiofilm effect of Van-MSNs was not significant. However, Van-MSNs did not affect bacterial attachment to surfaces. Van-loaded MSNs did not show a considerable effect on the lysis and sedimentation of RBC. A low interaction of Van-MSNs was detected with albumin (66.5 kDa). The hBM-MSCs viability in exposure to different levels of Van-MSNs was 91-100%. MICs of ≥ 128 µg/mL were observed for vancomycin against all Gram-negative bacteria. In contrast, Van-MSNs exhibited modest antibacterial activity inhibiting the tested Gram-negative bacterial strains, at concentrations of ≤ 16 µg/mL. Van-MSNs increased the OM permeability of bacteria that can increase the antimicrobial effect of vancomycin. According to our findings, Van-loaded MSNs have low cytotoxicity, desirable biocompatibility, and antibacterial effects and can be an option for the battle against planktonic MRSA.}, }
@article {pmid36883149, year = {2022}, author = {Makhrmash, JH and Al-Aidy, SR and Qaddoori, BH}, title = {Investigation of Biofilm Virulence Genes Prevalence in Klebsiella pneumoniae Isolated from the Urinary Tract Infections.}, journal = {Archives of Razi Institute}, volume = {77}, number = {4}, pages = {1421-1427}, pmid = {36883149}, issn = {2008-9872}, abstract = {Klebsiella pneumonia is a pathogen and an agent that causes hospital-acquired infections. Klebsiella pneumonia is the first and most common causative agent in community-acquired infections and urinary tract diseases. This study aimed to detect common genes, (i.e., fimA, mrkA, and mrkD) in the isolates of K. pneumoniae, isolated from urine specimens using the polymerase chain reaction (PCR) method. The isolates of K. pneumoniae were collected from urine specimens in health centers in Wasit Governorate, Iraq, and diagnosed using Analytical Profile Index 20Eand 16S rRNA techniques. The microtiter plate (MTP) method was used to detect biofilm formation. A total of 56 isolates were identified as K. pneumonia cases. The results led to the detection of biofilms; accordingly, all K. pneumoniae isolates showed biofilm production by MTP, however, at different levels. The PCR method was employed to detect biofilm genes and showed that 49 (87.5%), 26 (46.4%), and 30 (53.6%) of isolates carried fimH, mrkA, and mrkD, respectively. Furthermore, susceptibility tests for different antibiotics revealed that K. pneumoniae isolates were resistant to amoxicillin-clavulanic acid (n=11, 19.5%), ceftazidime (n=13, 22.4%), ofloxacin (n=16, 28.1%), and tobramycin (n=27, 48.4%). It was also found all K. pneumonia isolates were sensitive to polymyxin B (92.6%), imipenem (88.3%), meropenem (79.4%), and amikacin (60.5%).}, }
@article {pmid36882931, year = {2023}, author = {Magagula, S and Petzer, IM and Famuyide, IM and Karzis, J}, title = {Biofilm expression and antimicrobial resistance patterns of Streptococcus uberis isolated from milk samples of dairy cows in South Africa.}, journal = {The Journal of dairy research}, volume = {}, number = {}, pages = {1-5}, doi = {10.1017/S0022029923000158}, pmid = {36882931}, issn = {1469-7629}, abstract = {The research described in this Research Communication addresses the hypothesis that intramammary infections with Streptococcus uberis (S. uberis) are associated with biofilm formation, which limits antibiotic efficacy. This retrospective study investigated biofilm expression and antimicrobial resistance (AMR) patterns of 172 S. uberis infections. Isolates were recovered from milk samples of subclinical, clinical, and intramammary infection cases on 30 commercial dairy herds. We determined the presence and intensity of biofilm expression of S. uberis isolates in vitro in three somatic cell count categories to recognise their AMR patterns. An automated minimum inhibitory concentration system with a commercially available panel of 23 antimicrobial agents evaluated AMR, while biofilm determination was conducted using a microplate method. The study established that all the S. uberis isolates assessed expressed biofilm with the following varying degrees of intensities: 30 (17.8%) strong, 59 (34.9%) medium and 80 (47.3%) weak biofilms. The newly registered UBAC mastitis vaccine containing biofilm adhesion components may, therefore, be a viable option for proactive mastitis management under field conditions. No differences were identified between biofilm intensity and the three somatic cell count groups. Most S. uberis isolates indicated a high-level sensitivity to the antimicrobial agents tested. Resistances were present in 8.7, 8.1 and 7.0% cases to rifampin, minocycline and tetracycline, respectively. Multidrug resistance was observed in 6.4%, emphasising AMR to antibiotics used in human medicine only. The low overall resistance suggests that farmers adhere to the prudent use of antimicrobials in the dairy industry.}, }
@article {pmid36881023, year = {2023}, author = {Contreas, L and Hook, AL and Winkler, DA and Figueredo, G and Williams, P and Laughton, CA and Alexander, MR and Williams, PM}, title = {Linear Binary Classifier to Predict Bacterial Biofilm Formation on Polyacrylates.}, journal = {ACS applied materials &amp; interfaces}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsami.2c23182}, pmid = {36881023}, issn = {1944-8252}, abstract = {Bacterial infections are increasingly problematic due to the rise of antimicrobial resistance. Consequently, the rational design of materials naturally resistant to biofilm formation is an important strategy for preventing medical device-associated infections. Machine learning (ML) is a powerful method to find useful patterns in complex data from a wide range of fields. Recent reports showed how ML can reveal strong relationships between bacterial adhesion and the physicochemical properties of polyacrylate libraries. These studies used robust and predictive nonlinear regression methods that had better quantitative prediction power than linear models. However, as nonlinear models' feature importance is a local rather than global property, these models were hard to interpret and provided limited insight into the molecular details of material-bacteria interactions. Here, we show that the use of interpretable mass spectral molecular ions and chemoinformatic descriptors and a linear binary classification model of attachment of three common nosocomial pathogens to a library of polyacrylates can provide improved guidance for the design of more effective pathogen-resistant coatings. Relevant features from each model were analyzed and correlated with easily interpretable chemoinformatic descriptors to derive a small set of rules that give model features tangible meaning that elucidate relationships between the structure and function. The results show that the attachment of Pseudomonas aeruginosa and Staphylococcus aureus can be robustly predicted by chemoinformatic descriptors, suggesting that the obtained models can predict the attachment response to polyacrylates to identify anti-attachment materials to synthesize and test in the future.}, }
@article {pmid36879323, year = {2023}, author = {Ghezzi, D and Boi, M and Sassoni, E and Valle, F and Giusto, E and Boanini, E and Baldini, N and Cappelletti, M and Graziani, G}, title = {Customized biofilm device for antibiofilm and antibacterial screening of newly developed nanostructured silver and zinc coatings.}, journal = {Journal of biological engineering}, volume = {17}, number = {1}, pages = {18}, pmid = {36879323}, issn = {1754-1611}, abstract = {BACKGROUND: Bacterial colonisation on implantable device surfaces is estimated to cause more than half of healthcare-associated infections. The application of inorganic coatings onto implantable devices limits/prevents microbial contaminations. However, reliable and high-throughput deposition technologies and experimental trials of metal coatings for biomedical applications are missing. Here, we propose the combination of the Ionized Jet Deposition (IJD) technology for metal-coating application, with the Calgary Biofilm Device (CBD) for high-throughput antibacterial and antibiofilm screening, to develop and screen novel metal-based coatings.<br><br>RESULTS: The films are composed of nanosized spherical aggregates of metallic silver or zinc oxide with a homogeneous and highly rough surface topography. The antibacterial&#xa0;and&#xa0;antibiofilm activity of the coatings is related with the Gram staining, being Ag and Zn coatings more effective against gram-negative and gram-positive bacteria, respectively. The antibacterial/antibiofilm effect is proportional to the amount of metal deposited that influences the amount of metal ions released. The roughness also impacts the activity, mostly for Zn coatings. Antibiofilm properties are stronger on biofilms developing on the coating than on biofilms formed on uncoated substrates. This suggests a higher antibiofilm effect arising from the direct contact bacteria-coating than that associated with the metal ions release. Proof-of-concept of application to titanium alloys, representative of orthopaedic prostheses, confirmed the antibiofilm results, validating the approach. In addition, MTT tests show that the coatings are non-cytotoxic and ICP demonstrates that they have suitable release duration (>&#x2009;7&#xa0;days), suggesting the applicability of these new generation metal-based coatings for the functionalization of biomedical devices.<br><br>CONCLUSIONS: The combination of the Calgary Biofilm Device with the Ionized Jet Deposition technology proved to be an innovative and powerful tool that allows to monitor both the metal ions release and the surface topography of the films, which makes it suitable for the study of the antibacterial and antibiofilm activity of nanostructured materials. The results obtained with&#xa0;the CBD were validated with coatings on titanium alloys and extended by also considering the anti-adhesion properties and biocompatibility. In view of upcoming application in orthopaedics, these evaluations would be useful for the development of materials with pleiotropic antimicrobial mechanisms.}, }
@article {pmid36878870, year = {2023}, author = {Qiu, X and Han, X and Zhang, X and Teng, LA and Sriwastva, MK and Zhen, L and Li, Z and Liu, M and Ren, Y and Wang, S}, title = {Lactobacillus rhamnosus GG alleviates colitis caused by chemotherapy via biofilm formation.}, journal = {Journal of gastroenterology and hepatology}, volume = {}, number = {}, pages = {}, doi = {10.1111/jgh.16164}, pmid = {36878870}, issn = {1440-1746}, abstract = {BACKGROUND: Severe colitis is a common side effect of chemotherapy in cancer patients. In this study, we attempted to enhance the viability of probiotics in a gastric acid environment and improve the colitis induced by dextran sulfate sodium (DSS) and docetaxel.<br><br>METHODS: We purified Lactobacillus from yogurt and estimated their growth at pH 6.8 and pH 2.0. In the further investigation, the bacterial biofilm formation was used to define the mechanism by which administration of Lactobacillus rhamnosus (LGG) via oral gavage alleviates the colitis and intestine permeability of the mice induced by DSS and docetaxel. The potential benefit of probiotics on the treatment of breast cancer metastasis has been assessed as well.<br><br>RESULTS: Lactobacillus from yogurt growth was unexpectedly faster in the pH 2.0 than in the neutral pH medium during the first hour. LGG administered in the fasting state via oral gavage significantly improved the preventive effect in the colitis caused by DSS and docetaxel. LGG reduced the permeability of the intestine and decreased the expression of proinflammatory cytokines, TNF&#x3b1;, IL-1&#x3b2;, and IL-6, in colitis by biofilm formation. Increasing the docetaxel dose may reduce breast tumor growth and metastasis in the lung but did not benefit survival due to severe colitis. However, the LGG supplement significantly improved the survival of tumor-bearing mice following a high dose of docetaxel treatment.<br><br>CONCLUSIONS: Our findings provide new insights into the potential mechanism of probiotic protection of the intestine and provide a novel therapeutic strategy to augment the chemotherapeutic treatment of tumors.}, }
@article {pmid36879587, year = {2019}, author = {Rastegar Khosravi, M and Khonsha, M and Ramazanzadeh, R}, title = {Combined Effect of Levofloxacin and N-Acetylcysteine against Enterococcus faecalis Biofilm for Regenerative Endodontics: An in Vitro Study.}, journal = {Iranian endodontic journal}, volume = {14}, number = {1}, pages = {40-46}, pmid = {36879587}, issn = {2008-2746}, abstract = {INTRODUCTION: Endodontic treatment of necrotic immature teeth poses several clinical challenges. A major problem is the elimination of microorganisms from the root canal system. This study evaluates the in vitro antibacterial efficacy of ciprofloxacin (CIP), levofloxacin (LEV), and their combination with N-acetylcysteine (NAC) in root canals infected with Enterococcus faecalis (E. faecalis).<br><br>METHODS AND MATERIALS: A total of 120 human extracted teeth with single canals were prepared and randomly divided into six groups: Calcium hydroxide (CH), ciprofloxacin (CIP), levofloxacin (LEV), ciprofloxacin and N-acetylcysteine (CIP+NAC), levofloxacin and N-acetylcysteine (LEV+NAC), and normal saline as a positive control. According to the name of the groups, intracanal medicaments were placed into the canals and the teeth were restored with a temporary filling. After one week, intracanal medicament was removed and the final count of bacteria was measured. Antibacterial effect of medicament was assessed by measuring the percentage reduction in the colony counts (RCC) and scanning electron microscopy (SEM). The Mann-Whitney U test and the Kruskal-Wallis test were used to compare the overall antibacterial efficacy of the intracanal medicaments at significance level of 0.05.<br><br>RESULTS: All intracanal medicaments were significantly more effective than calcium hydroxide (P<0.05). The combination of LEV and NAC caused significantly higher reduction in colony count in comparison with other tested medicaments (P=0.001).<br><br>CONCLUSION: The combination of LEV and NAC showed greater antibacterial activity compared with other tested medicaments against biofilm of E. faecalis. Thus, it has the potential to be used in regenerative endodontic treatments.}, }
@article {pmid36883019, year = {2018}, author = {Ghahramani, Y and Yaghoobi, F and Motamedi, R and Jamshidzadeh, A and Abbaszadegan, A}, title = {Effect of Endodontic Irrigants and Medicaments Mixed with Silver Nanoparticles against Biofilm Formation of Enterococcus faecalis.}, journal = {Iranian endodontic journal}, volume = {13}, number = {4}, pages = {559-564}, pmid = {36883019}, issn = {2008-2746}, abstract = {INTRODUCTION: The aim of this study was to evaluate the effectiveness of chlorhexidine (CHX), sodium hypochlorite (NaOCl), calcium hydroxide (CH) and double antibiotic paste (DAP) mixed with silver nanoparticles (AgNPs) against Enterococcus faecalis .<br><br>METHODS AND MATERIALS: Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and biofilm formation inhibition (after 72 h) of the experimental substances alone or mixed with AgNPs were measured against E. faecalis using microtiter plate method. Bacterial cultures turbidity was measured using a spectrophotometer. All procedures were performed in triplicates.<br><br>RESULTS: The MIC values for CHX, NaOCl, CH and DAP were equal to 0.012, 1.25, 1.6 and 0.156 mg/mL, and their MBC's were 0.025, 2.5, 0 and 0.625 mg/mL. After mixing them with AgNPs, the MIC's for CHX, NaOCl, CH and DAP were reduced to 0.0032, 0.158, 0.2 and 0.0391 mg/mL, while their MBC's were reduced to 0.0064, 0.0632, 0.401 and 0.0156 mg/mL. Biofilm formation inhibition occurred in higher dilutions of all irrigants and medicaments as they were mixed with Ag NPs.<br><br>CONCLUSIONS: Adding AgNPs resulted in an increased antimicrobial activity at the tested dilutions for all experimental substances. More investigations in in vivo conditions are required to confirm the results of this study.}, }
@article {pmid36878335, year = {2023}, author = {Al-Saafin, BA and Al-Bakri, AG and Abdelrazig, S and Dahabiyeh, LA}, title = {Investigating the effect of the probiotic Lactobacillus plantarum and the prebiotic fructooligosaccharides on Pseudomonas aeruginosa metabolome, virulence factors and biofilm formation as potential quorum sensing inhibitors.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106057}, doi = {10.1016/j.micpath.2023.106057}, pmid = {36878335}, issn = {1096-1208}, abstract = {Pseudomonas aeruginosa (P. aeruginosa) uses quorum sensing signaling (QS) molecules to control the expression of virulence factors and biofilm formation. In this study, the effects of the probiotic's (Lactobacillus plantarum (L. plantarum)) lysate and cell-free supernatant and the prebiotic (Fructooligosaccharides (FOS)) on the levels of P. aeruginosa QS molecules, virulence factors, biofilm density and metabolites were observed. These effects were investigated using exofactor assays, crystal violet and liquid chromatography-mass spectrometry (LC-MS)-based metabolomics approach. Results showed that in comparison to untreated P. aeruginosa, the L. plantarum cell-free supernatant (5%) and FOS (2%) significantly reduced the levels of the virulence factor pyoverdine (PVD) and several metabolites in the QS pathway including Pseudomonas autoinducer-2 (PAI-2). Metabolomics study revealed that the level of different secondary metabolites involved in the biosynthesis of vitamins, amino acids and the tricarboxylic acid (TCA) cycle were also affected. L. Plantarum was found to have a higher impact on the metabolomics profile of P. aeruginosa and its QS molecules compared to FOS. Lastly, a decrease in the formation of the P. aeruginosa biofilm was observed in a time-dependent pattern upon treatment with either cell-free supernatant of L. plantarum (5%), FOS (2%) or a combination of both treatments (5% + 2%). The latter showed the highest effect with 83% reduction in biofilm density at 72 h incubation. This work highlighted the important role probiotics and prebiotics play as potential QS inhibitors for P. aeruginosa. Moreover, it demonstrated the significant role of LC-MS metabolomics for investigating the altered biochemical and QS pathways in P. aeruginosa.}, }
@article {pmid36878334, year = {2023}, author = {Lau, TV and Puah, SM and Tan, JMA and Merino, S and Puthucheary, SD and Chua, KH}, title = {Flagellar motility mediates biofilm formation in Aeromonas dhakensis.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {106059}, doi = {10.1016/j.micpath.2023.106059}, pmid = {36878334}, issn = {1096-1208}, abstract = {Aeromonas dhakensis possesses dual flagellar systems for motility under different environments. Flagella-mediated motility is necessary for biofilm formation through an initial attachment of bacteria to the surface, but this has not been elucidated in A. dhakensis. This study investigates the role of polar (flaH, maf1) and lateral (lafB, lafK and lafS) flagellar genes in the biofilm formation of a clinical A. dhakensis strain WT187 isolated from burn wound infection. Five deletion mutants and corresponding complemented strains were constructed using pDM4 and pBAD33 vectors, respectively, and analyzed for motility and biofilm formation using crystal violet staining and real-time impedance-based assays. All mutants were significantly reduced in swimming (p < 0.0001), swarming (p < 0.0001) and biofilm formation using crystal violet assay (p < 0.05). Real-time impedance-based analysis revealed WT187 biofilm was formed between 6-21 h, consisting of early (6-10 h), middle (11-18 h), and late (19-21 h) stages. The highest cell index of 0.0746 was recorded at 22-23 h and biofilms began to disperse starting from 24 h. Mutants Δmaf1, ΔlafB, ΔlafK and ΔlafS exhibited reduced cell index values at 6-48 h when compared to WT187 which indicates less biofilm formation. Two complemented strains cmaf1 and clafB exhibited full restoration to wild-type level in swimming, swarming, and biofilm formation using crystal violet assay, hence suggesting that both maf1 and lafB genes are involved in biofilm formation through flagella-mediated motility and surface attachment. Our study shows the role of flagella in A. dhakensis biofilm formation warrants further investigations.}, }
@article {pmid36877588, year = {2023}, author = {Ding, Y and Ma, R and Liu, G and Li, X and Xu, K and Liu, P and Cai, K}, title = {Fabrication of a New Hyaluronic Acid/Gelatin Nanocomposite Hydrogel Coating on Titanium-Based Implants for Treating Biofilm Infection and Excessive Inflammatory Response.}, journal = {ACS applied materials &amp; interfaces}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsami.2c23320}, pmid = {36877588}, issn = {1944-8252}, abstract = {Persistent inflammation caused by implant-associated biofilm infections has emerged as a significant clinical issue. While many methods have been developed to give implants great anti-biofilm benefits, the post-inflammatory microenvironment is frequently disregarded. Oxidative stress (OS) due to excessive reactive oxygen species (ROS) is considered to be one of the specific physiological signals of the inflammation microenvironment. Herein, ZIF-90-Bi-CeO2 nanoparticles (NPs) were incorporated into a Schiff-base chemically crosslinked hydrogel composed of aldehyde-based hyaluronic acid and gelatin. Through chemical crosslinking between polydopamine and gelatin, the hydrogel coating adhered to the Ti substrate. The modified Ti substrate gained multimodal antibacterial and anti-biofilm functions, which were attributed to the photothermal effect of Bi NPs, and the release of Zn ions and CeO2 NPs. Notably, CeO2 NPs endowed the system with dual-enzyme (SOD- and CAT-like) catalytic activities. In a rat implant-associated infection (IAI) model, the dual-functional hydrogel had a biofilm-removal ability and regulated OS and inflammatory responses to facilitate osseointegration. The photothermal therapy combined with a host inflammation-microenvironment regulation strategy might provide a novel treatment for biofilm infection and the accompanying excessive inflammation.}, }
@article {pmid36877407, year = {2023}, author = {Han, J and Luo, J and Du, Z and Chen, Y and Liu, T}, title = {Synergistic Effects of Baicalin and Levofloxacin Against Hypervirulent Klebsiella pneumoniae Biofilm In Vitro.}, journal = {Current microbiology}, volume = {80}, number = {4}, pages = {126}, pmid = {36877407}, issn = {1432-0991}, abstract = {Hypervirulent Klebsiella pneumoniae (hvKp) strains that form biofilms have recently emerged worldwide; however, the mechanisms underlying biofilm formation and disruption remain elusive. In this study, we established a hvKp biofilm model, investigated its in vitro formation pattern, and determined the mechanism of biofilm destruction by baicalin (BA) and levofloxacin (LEV). Our results revealed that hvKp exhibited a strong biofilm-forming ability, forming early and mature biofilms after 3 and 5 d, respectively. Early biofilm and bacterial burden were significantly reduced by BA + LEV and EM + LEV treatments, which destroyed the 3D structure of early biofilms. Conversely, these treatments were less effective against mature biofilm. The expression of both AcrA and wbbM was significantly downregulated in the BA + LEV group. These findings indicated that BA + LEV might inhibit the formation of hvKp biofilm by altering the expression of genes regulating efflux pumps and lipopolysaccharide biosynthesis.}, }
@article {pmid36875729, year = {2023}, author = {Haroon, U and Munis, MFH and Liaquat, F and Khizar, M and Elahi, M and Chaudhary, HJ}, title = {Biofilm formation and flocculation potential analysis of halotolerant Bacillus tequilensis and its inoculation in soil to mitigate salinity stress of chickpea.}, journal = {Physiology and molecular biology of plants : an international journal of functional plant biology}, volume = {29}, number = {2}, pages = {277-288}, pmid = {36875729}, issn = {0971-5894}, abstract = {UNLABELLED: Application of beneficial microbes in soil is an important avenue to control plant stresses. In this study, the salinity tolerance of halotolerant bacteria (Bacillus tequilensis) was investigated and the bacterium was inoculated in the soil to mitigate salinity stress. The results revealed the highest floc yield and biofilm formation ability of B. tequilensis at 100 mM NaCl concentration. Fourier transformed infrared spectroscopy depicted the presence of carbohydrates and proteins which binds with sodium ions (Na[+]) and provide tolerance against salinity. Using PCR, plant growth-promoting bacterial genes viz., 1-aminocyclopropane-1-carboxylate deaminase and pyrroloquinoline quinone were successfully amplified from the genome of B. tequilensis. In the saline soil, B. tequilensis was inoculated and chickpea plants were grown. The bacterial strain improved the physiology, biochemistry, and antioxidant enzyme activities of the chickpea plant under salt stress. Plants inoculated with B. tequilensis exhibited higher relative water content, higher photosynthetic pigments, lower levels of hydrogen peroxide (H2O2) and malondialdehyde, and improved enzymatic activity for the scavenging of reactive oxygen species. The findings of this study suggest the sustainable use of B. tequilensis to mitigate the salinity stress of chickpea and other crops. This bacterium not only helps in the alleviation of the toxic effects of salt but also increases plant growth along with a reduction in crop losses due to salinity.<br><br>SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12298-023-01280-1.}, }
@article {pmid36875516, year = {2023}, author = {Wells, M and Schneider, R and Bhattarai, B and Currie, H and Chavez, B and Christopher, G and Rumbaugh, K and Gordon, V}, title = {Perspective: The viscoelastic properties of biofilm infections and mechanical interactions with phagocytic immune cells.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1102199}, pmid = {36875516}, issn = {2235-2988}, abstract = {Biofilms are viscoelastic materials that are a prominent public health problem and a cause of most chronic bacterial infections, in large part due to their resistance to clearance by the immune system. Viscoelastic materials combine both solid-like and fluid-like mechanics, and the viscoelastic properties of biofilms are an emergent property of the intercellular cohesion characterizing the biofilm state (planktonic bacteria do not have an equivalent property). However, how the mechanical properties of biofilms are related to the recalcitrant disease that they cause, specifically to their resistance to phagocytic clearance by the immune system, remains almost entirely unstudied. We believe this is an important gap that is ripe for a large range of investigations. Here we present an overview of what is known about biofilm infections and their interactions with the immune system, biofilm mechanics and their potential relationship with phagocytosis, and we give an illustrative example of one important biofilm-pathogen (Pseudomonas aeruginosa) which is the most-studied in this context. We hope to inspire investment and growth in this relatively-untapped field of research, which has the potential to reveal mechanical properties of biofilms as targets for therapeutics meant to enhance the efficacy of the immune system.}, }
@article {pmid36873470, year = {2023}, author = {Rezende Mires de Carvalho, R and Silva Dias, C and Nogueira Paz, L and Melo de Lima Fires, T and Pereira Figueira, C and Araújo Damasceno, K and Hanzen Pinna, M}, title = {Biofilm formation in vitro by Leptospira interrogans strains isolated from naturally infected dogs and their role in antimicrobial resistance.}, journal = {Heliyon}, volume = {9}, number = {3}, pages = {e13802}, pmid = {36873470}, issn = {2405-8440}, abstract = {Leptospira interrogans is a biofilm-forming pathogen, however, there are few data involving Brazilian strains isolated from dogs and their antimicrobial sensitivity in planktonic and biofilm forms. The potential for biofilm formation and antimicrobial resistance in naturally infected dogs is a fundamental approach towards disease epidemiology and the establishment of consistent prophylaxis and control measures. The objective of this study was to evaluate in vitro biofilm formation of a reference strain (L. interrogans, sv. Copenhageni L1 130 - L20) and of L. interrogans isolated from dogs (C20, C29, C51, C82), with subsequent evaluation of antimicrobial susceptibility in planktonic and biofilm forms. The semi quantification of biofilm production revealed a dynamic process of development over time, with mature biofilm formation early on the seventh day of incubation. All strains were efficient for in vitro biofilm formation and, in this form, they were considerably more resistant compared to their planktonic form, with MIC90 of 1600 μg/mL for amoxicillin, 800 μg/mL for ampicillin, and >1600 μg/mL for doxycycline and ciprofloxacin. The strains studies were isolated on naturally infected dogs that might act as reservoirs and sentinels for human infections. The potential to antimicrobial resistance together with the close relation between dogs and humans indicates the need for greater actions on disease control and surveillance. Moreover, biofilm formation may contribute to the persistence of Leptospira interrogans in the host and these animals can act as chronic carriers, disseminating the agent in the environment.}, }
@article {pmid36870235, year = {2023}, author = {Yang, H and Zhan, X and Song, L and Cheng, S and Su, R and Zhang, Y and Guo, D and Lü, X and Xia, X and Shi, C}, title = {Synergistic antibacterial and anti-biofilm mechanisms of ultrasound combined with citral nanoemulsion against Staphylococcus aureus 29213.}, journal = {International journal of food microbiology}, volume = {391-393}, number = {}, pages = {110150}, doi = {10.1016/j.ijfoodmicro.2023.110150}, pmid = {36870235}, issn = {1879-3460}, abstract = {This study investigated the antibacterial and antibiofilm mechanism of ultrasound (US) combined with citral nanoemulsion (CLNE) against Staphylococcus aureus and mature biofilm. Combined treatments resulted in greater reductions in bacterial numbers compared to ultrasound or CLNE treatments alone. Confocal laser scanning microscopy (CLSM), flow cytometry (FCM), protein nucleic acid leakage, and N-phenyl-l-naphthylamine (NPN) uptake analysis showed that the combined treatment disrupted cell membrane integrity and permeability. Reactive oxygen species (ROS) and malondialdehyde (MDA) assays indicated that US+CLNE exacerbated cellular oxidative stress and membrane lipid peroxidation. Field emission scanning electron microscopy (FESEM) revealed that the synergistic processing of ultrasound and CLNE resulted in cell rupture and collapse. In addition, US+CLNE showed a more pronounced removal effect than both alone in the biofilm on the stainless steel sheet. US+CLNE reduced biomass, the number of viable cells in the biofilm, cell viability and EPS polysaccharide contents. The results of CLSM also showed that US+CLNE disrupted the structure of the biofilm. This research elucidates the synergistic antibacterial and anti-biofilm mechanism of ultrasound combined citral nanoemulsion, which provides a safe and efficient sterilization method for the food industry.}, }
@article {pmid36870201, year = {2023}, author = {Verma, NK and Dewangan, RP and Harioudh, MK and Ghosh, JK}, title = {Introduction of a β-leucine residue instead of leucine[9] and glycine[10] residues in Temporin L for improved cell selectivity, stability and activity against planktonic and biofilm of methicillin resistant S. aureus.}, journal = {Bioorganic chemistry}, volume = {134}, number = {}, pages = {106440}, doi = {10.1016/j.bioorg.2023.106440}, pmid = {36870201}, issn = {1090-2120}, abstract = {Leucine and glycine residues, at the 9th and 10th positions of helical domain of naturally occurring antimicrobial peptide (AMP), Temporin L were substituted with an unnatural amino acid, β-leucine (homovaline) to improve its serum protease stability, haemolytic/cytotoxic properties and reduce the size to some extent. The designed analogue, L9βl-TL showed either equal or improved antimicrobial activity to TL against different microorganisms including the resistant strains. Interestingly, L9βl-TL also exhibited lower haemolytic and cytotoxic activities against human red blood cells and 3T3 cells, respectively. Moreover, L9βl-TL showed antibacterial activity in presence of 25% (v/v) human serum and showed resistance against proteolytic cleavage in presence of it that suggested the serum protease stability of the TL-analogue. L9βl-TL exhibited un-ordered secondary structures in both bacterial and mammalian membrane mimetic lipid vesicles as compared to the helical structures of TL in these environments. However, tryptophan fluorescence studies demonstrated more selective interaction of L9βl-TL with bacterial membrane mimetic lipid vesicles in comparison to non-selective interactions of TL with both kinds of lipid vesicles. Membrane depolarization studies with live MRSA and bacterial membrane-mimetic lipid vesicles suggested a membrane-disrupting mode of action of L9βl-TL. L9βl-TL showed faster bactericidal mechanism compared to TL against MRSA. Interestingly, L9βl-TL was found as more potent than TL either in inhibiting biofilm formation or in eradicating the mature biofilm formed by MRSA. Overall, the present work demonstrates a simple and useful strategy to design of an analogue of TL, with minimal modifications while maintaining its antimicrobial activity with lesser toxicity and higher stability which could be attempted for other AMPs as well.}, }
@article {pmid36869686, year = {2023}, author = {Ramezani, M and Monroe, MBB}, title = {Bacterial protease-responsive shape memory polymers for infection surveillance and biofilm inhibition in chronic wounds.}, journal = {Journal of biomedical materials research. Part A}, volume = {}, number = {}, pages = {}, doi = {10.1002/jbm.a.37527}, pmid = {36869686}, issn = {1552-4965}, abstract = {Chronic wound healing is often negatively impacted by infection. Efficient infection assessment is crucial for effective treatment, and biofilm inhibition could improve treatment efficacy. To that end, we developed a bacterial protease-responsive shape memory polymer based on a segmented polyurethane with incorporated poly(glutamic acid) peptide (PU-Pep). Poly(glutamic acid) degrades in response to bacterial proteases to trigger shape recovery of PU-Pep films that are programmed into a secondary shape. These materials have transition temperatures well above body temperature (~60°C), which enables stable storage in temporary shapes after implantation. Synthesized polymers have high shape fixity (~74%-88%), shape recovery (~93%-95%), and cytocompatibility (~100%). Strained PU-Pep samples underwent shape recovery within ≤24 h in response to the V8 enzyme from Staphylococcus aureus (S. aureus, ~50% recovery) and multiple bacteria strains (S. aureus [~40%], Staphylococcus epidermidis [~30%], and Escherichia coli [~25%]), and they had minimal shape change in response to media controls and mammalian cells. Shape recovery of strained PU-Pep samples prevented biofilm formation on the sample surfaces, and resulting attached planktonic bacteria were vulnerable to applied treatments. PU-Pep with physically incorporated antimicrobials simultaneously prevented biofilm formation and killed isolated bacteria. PU-Pep dressings displayed visible shape change and resistance to biofilm formation in in vitro and ex vivo models. In the in vitro model, PU-Pep shape change also disrupted pre-formed biofilm structures. This novel bacterial protease-responsive biomaterial could serve as a wound dressing that changes shape specifically during bacterial colonization to alert clinicians to infection and make biofilm-associated infections easier to treat.}, }
@article {pmid36869500, year = {2023}, author = {Lake, FB and van Overbeek, LS and Baars, JJP and Abee, T and den Besten, HMW}, title = {Variability in growth and biofilm formation of Listeria monocytogenes in Agaricus bisporus mushroom products.}, journal = {Food research international (Ottawa, Ont.)}, volume = {165}, number = {}, pages = {112488}, doi = {10.1016/j.foodres.2023.112488}, pmid = {36869500}, issn = {1873-7145}, abstract = {Foods and food production environments can be contaminated with Listeria monocytogenes and may support growth of this foodborne pathogen. This study aims to characterize the growth and biofilm formation of sixteen L. monocytogenes strains, isolated from mushroom production and processing environments, in filter-sterilized mushroom medium. Strain performance was compared to twelve L. monocytogenes strains isolated from other sources including food and human isolates. All twenty-eight L. monocytogenes strains showed rather similar growth performance at 20 °C in mushroom medium, and also significant biofilm formation was observed for all strains. HPLC analysis revealed the presence of mannitol, trehalose, glucose, fructose and glycerol, that were all metabolized by L. monocytogenes, except mannitol, in line with the inability of L. monocytogenes to metabolize this carbohydrate. Additionally, the growing behavior of L. monocytogenes was tested on whole, sliced and smashed mushroom products to quantify performance in the presence of product-associated microbiota. A significant increase of L. monocytogenes was observed with higher increase of counts when the mushroom products were more damaged, even with the presence of high background microbiota counts. This study demonstrated that L. monocytogenes grows well in mushroom products, even when the background microbiota is high, highlighting the importance to control (re)contamination of mushrooms.}, }
@article {pmid36867905, year = {2023}, author = {Deng, Y and Yang, G and Lens, PNL and He, Y and Qie, L and Shen, X and Chen, J and Cheng, Z and Chen, D}, title = {Enhanced removal of mixed VOCs with different hydrophobicities by Tween 20 in a biotrickling filter: Kinetic analysis and biofilm characteristics.}, journal = {Journal of hazardous materials}, volume = {450}, number = {}, pages = {131063}, doi = {10.1016/j.jhazmat.2023.131063}, pmid = {36867905}, issn = {1873-3336}, abstract = {Mass transfer limitation usually causes the poor performance of biotrickling filters (BTFs) for the treatment of hydrophobic volatile organic compounds (VOCs) during long-term operation. In this study, two identical lab-scale BTFs were established to remove a mixture of n-hexane and dichloromethane (DCM) gases using non-ionic surfactant Tween 20 by Pseudomonas mendocina NX-1 and Methylobacterium rhodesianum H13. A low pressure drop (≤110 Pa) and a rapid biomass accumulation (17.1 mg g[-1]) were observed in the presence of Tween 20 during the startup period (30 d). The removal efficiency (RE) of n-hexane was enhanced by 15.0%- 20.5% while DCM was completely removed with the inlet concentration (IC) of 300 mg·m[-3] at different empty bed residence times in the Tween 20 added BTF. The viable cells and the relative hydrophobicity of the biofilm were increased under the action of Tween 20, which facilitated the mass transfer and enhanced the metabolic utilization of pollutants by microbes. Besides, Tween 20 addition enhanced the biofilm formation processes including the increased extracellular polymeric substance (EPS) secretion, biofilm roughness and biofilm adhesion. The kinetic model simulated the removal performance of the BTF with Tween 20 for the mixed hydrophobic VOCs, and the goodness-of-fit was above 0.9.}, }
@article {pmid36865097, year = {2023}, author = {Arbour, CA and Nagar, R and Bernstein, HM and Ghosh, S and Al-Sammarraie, Y and Dorfmueller, HC and Ferguson, MAJ and Stanley-Wall, NR and Imperiali, B}, title = {Defining Early Steps in B. subtilis Biofilm Biosynthesis.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.02.22.529487}, pmid = {36865097}, abstract = {UNLABELLED: The Bacillus subtilis extracellular biofilm matrix includes an exopolysaccharide that is critical for the architecture and function of the community. To date, our understanding of the biosynthetic machinery and the molecular composition of the exopolysaccharide of B. subtilis remains unclear and incomplete. This report presents synergistic biochemical and genetic studies built from a foundation of comparative sequence analyses targeted at elucidating the activities of the first two membrane-committed steps in the exopolysaccharide biosynthetic pathway. By taking this approach, we determined the nucleotide sugar donor and lipid-linked acceptor substrates for the first two enzymes in the B. subtilis biofilm exopolysaccharide biosynthetic pathway. EpsL catalyzes the first phosphoglycosyl transferase step using UDP-di- N -acetyl bacillosamine as phospho-sugar donor. EpsD is a GT-B fold glycosyl transferase that facilitates the second step in the pathway that utilizes the product of EpsL as an acceptor substrate and UDP- N -acetyl glucosamine as the sugar donor. Thus, the study defines the first two monosaccharides at the reducing end of the growing exopolysaccharide unit. In doing so we provide the first evidence of the presence of bacillosamine in an exopolysaccharide synthesized by a Gram-positive bacterium.<br><br>IMPORTANCE: Biofilms are the communal way of life that microbes adopt to increase survival. Key to our ability to systematically promote or ablate biofilm formation is a detailed understanding of the biofilm matrix macromolecules. Here we identify the first two essential steps in the Bacillus subtilis biofilm matrix exopolysaccharide synthesis pathway. Together our studies and approaches provide the foundation for the sequential characterization of the steps in exopolysaccharide biosynthesis, using prior steps to enable chemoenzymatic synthesis of the undecaprenol diphosphate-linked glycan substrates.}, }
@article {pmid36864390, year = {2023}, author = {Asadi, S and Nayeri-Fasaei, B and Zahraei-Salehi, T and Yahya-Rayat, R and Shams, N and Sharifi, A}, title = {Antibacterial and anti-biofilm properties of carvacrol alone and in combination with cefixime against Escherichia coli.}, journal = {BMC microbiology}, volume = {23}, number = {1}, pages = {55}, pmid = {36864390}, issn = {1471-2180}, abstract = {BACKGROUND: Plant-derived compounds can be used as antimicrobial agents in medicines and as food preservatives. These compounds can be applied along with other antimicrobial agents to strengthen the effect and/or reduce the required treatment dose.<br><br>RESULTS: In the present study, the antibacterial, anti-biofilm and quorum sensing inhibitory activity of carvacrol alone and in combination with the antibiotic cefixime against Escherichia coli was investigated. The MIC and MBC values for carvacrol were 250&#xa0;&#x3bc;g/mL. In the checkerboard test, carvacrol showed a synergistic interaction with cefixime against E. coli (FIC index&#x2009;=&#x2009;0.5). Carvacrol and cefixime significantly inhibited biofilm formation at MIC/2 (125 and 62.5&#xa0;&#x3bc;g/mL), MIC/4 (62.5 and 31.25&#xa0;&#x3bc;g/mL) and MIC/8 (31.25 and 15.625&#xa0;&#x3bc;g/mL) for carvacrol and cefixime, respectively. The antibacterial and anti-biofilm potential effect of carvacrol confirmed by the scanning electron microscopy. Real-time quantitative reverse transcription PCR revealed significant down-regulation of the luxS and pfs genes following treatment with a MIC/2 (125&#xa0;&#x3bc;g/mL) concentration of carvacrol alone and of only pfs gene following treatment with MIC/2 of carvacrol in combination with MIC/2 of cefixime (p&#x2009;<&#x2009;0.05).<br><br>CONCLUSIONS: Because of the significant antibacterial and anti-biofilm activity of carvacrol, the present study examines this agent as an antibacterial drug of natural origin. The results indicate that in this study the best antibacterial and anti-biofilm properties are for the combined use of cefixime and carvacrol.}, }
@article {pmid36864092, year = {2023}, author = {Frenkel, A and Zecharia, E and Gómez-Pérez, D and Sendersky, E and Yegorov, Y and Jacob, A and Benichou, JIC and Stierhof, YD and Parnasa, R and Golden, SS and Kemen, E and Schwarz, R}, title = {Cell specialization in cyanobacterial biofilm development revealed by expression of a cell-surface and extracellular matrix protein.}, journal = {NPJ biofilms and microbiomes}, volume = {9}, number = {1}, pages = {10}, pmid = {36864092}, issn = {2055-5008}, abstract = {Cyanobacterial biofilms are ubiquitous and play important roles in diverse environments, yet, understanding of the processes underlying the development of these aggregates is just emerging. Here we report cell specialization in formation of Synechococcus elongatus PCC 7942 biofilms-a hitherto unknown characteristic of cyanobacterial social behavior. We show that only a quarter of the cell population expresses at high levels the four-gene ebfG-operon that is required for biofilm formation. Almost all cells, however, are assembled in the biofilm. Detailed characterization of EbfG4 encoded by this operon revealed cell-surface localization as well as its presence in the biofilm matrix. Moreover, EbfG1-3 were shown to form amyloid structures such as fibrils and are thus likely to contribute to the matrix structure. These data suggest a beneficial 'division of labor' during biofilm formation where only some of the cells allocate resources to produce matrix proteins-'public goods' that support robust biofilm development by the majority of the cells. In addition, previous studies revealed the operation of a self-suppression mechanism that depends on an extracellular inhibitor, which supresses transcription of the ebfG-operon. Here we revealed inhibitor activity at an early growth stage and its gradual accumulation along the exponential growth phase in correlation with cell density. Data, however, do not support a threshold-like phenomenon known for quorum-sensing in heterotrophs. Together, data presented here demonstrate cell specialization and imply density-dependent regulation thereby providing deep insights into cyanobacterial communal behavior.}, }
@article {pmid36862938, year = {2023}, author = {Brezhnev, A and Tang, FK and Kwan, CS and Basabrain, MS and Tsoi, JKH and Matinlinna, JP and Neelakantan, P and Leung, KC}, title = {One-Pot Preparation of Cetylpyridinium Chloride-Containing Nanoparticles for Biofilm Eradication.}, journal = {ACS applied bio materials}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsabm.2c01080}, pmid = {36862938}, issn = {2576-6422}, abstract = {Quaternary ammonium compounds (QACs) have been widely used due to their excellent antimicrobial activity. However, using the technology where nanomaterials are employed as drug carriers to deliver QAC drugs has not been fully explored. In this study, mesoporous silica nanoparticles (MSNs) with short rod morphology were synthesized in a one-pot reaction using an antiseptic drug cetylpyridinium chloride (CPC). CPC-MSN were characterized via various methods and tested against three bacterial species (Streptococcus mutans, Actinomyces naeslundii, and Enterococcus faecalis), which are associated with oral infections, caries, and endodontic pathology. The nanoparticle delivery system used in this study prolonged the release of CPC. The manufactured CPC-MSN effectively killed the tested bacteria within the biofilm, and their size allowed them to penetrate into dentinal tubules. This CPC-MSN nanoparticle delivery system demonstrates potential for applications in dental materials.}, }
@article {pmid36862127, year = {2023}, author = {Ran, W and Yue, Y and Long, F and Zhong, K and Bai, J and Xiao, Y and Bu, Q and Huang, Y and Wu, Y and Gao, H}, title = {Antibacterial Mechanism of 2R,3R-Dihydromyricetin Against Staphylococcus aureus: Deciphering Inhibitory Effect on Biofilm and Virulence Based on Transcriptomic and Proteomic Analyses.}, journal = {Foodborne pathogens and disease}, volume = {}, number = {}, pages = {}, doi = {10.1089/fpd.2022.0075}, pmid = {36862127}, issn = {1556-7125}, abstract = {Staphylococcus aureus is a major foodborne pathogen that leads to various diseases due to its biofilm and virulence factors. This study aimed to investigate the inhibitory effect of 2R,3R-dihydromyricetin (DMY), a natural flavonoid compound, on the biofilm formation and virulence of S. aureus, and to explore the mode of action using transcriptomic and proteomic analyses. Microscopic observation revealed that DMY could remarkably inhibit the biofilm formation by S. aureus, leading to a collapse on the biofilm architecture and a decrease in viability of biofilm cell. Moreover, the hemolytic activity of S. aureus was reduced to 32.7% after treatment with subinhibitory concentration of DMY (p < 0.01). Bioinformation analysis based on RNA-sequencing and proteomic profiling revealed that DMY induced 262 differentially expressed genes and 669 differentially expressed proteins (p < 0.05). Many downregulated genes and proteins related to surface proteins were involved in biofilm formation, including clumping factor A (ClfA), iron-regulated surface determinants (IsdA, IsdB, and IsdC), fibrinogen-binding proteins (FnbA, FnbB), and serine protease. Meanwhile, DMY regulated a wide range of genes and proteins enriched in bacterial pathogenesis, cell envelope, amino acid metabolism, purine and pyrimidine metabolism, and pyruvate metabolism. These findings suggest that DMY targets S. aureus through multifarious mechanisms, and especially prompt that interference of surface proteins in cell envelope would lead to attenuation of biofilm and virulence.}, }
@article {pmid36860488, year = {2023}, author = {Poon, Y and Hui, M}, title = {Inhibitory effect of lactobacilli supernatants on biofilm and filamentation of Candida albicans, Candida tropicalis, and Candida parapsilosis.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1105949}, pmid = {36860488}, issn = {1664-302X}, abstract = {INTRODUCTION: Probiotic Lactobacillus strains had been investigated for the potential to protect against infection caused by the major fungal pathogen of human, Candida albicans. Besides antifungal activity, lactobacilli demonstrated a promising inhibitory effect on biofilm formation and filamentation of C. albicans. On the other hand, two commonly isolated non-albicans Candida species, C. tropicalis and C. parapsilosis, have similar characteristics in filamentation and biofilm formation with C. albicans. However, there is scant information of the effect of lactobacilli on the two species.<br><br>METHODS: In this study, biofilm inhibitory effects of L. rhamnosus ATCC 53103, L. plantarum ATCC 8014, and L. acidophilus ATCC 4356 were tested on the reference strain C. albicans SC5314 and six bloodstream isolated clinical strains, two each of C. albicans, C. tropicalis, and C. parapsilosis.<br><br>RESULTS AND DISCUSSION: Cell-free culture supernatants (CFSs) of L. rhamnosus and L. plantarum significantly inhibited in vitro biofilm growth of C. albicans and C. tropicalis. L. acidophilus, conversely, had little effect on C. albicans and C. tropicalis but was more effective on inhibiting C. parapsilosis biofilms. Neutralized L. rhamnosus CFS at pH 7 retained the inhibitory effect, suggesting that exometabolites other than lactic acid produced by the Lactobacillus strain might be accounted for the effect. Furthermore, we evaluated the inhibitory effects of L. rhamnosus and L. plantarum CFSs on the filamentation of C. albicans and C. tropicalis strains. Significantly less Candida filaments were observed after co-incubating with CFSs under hyphae-inducing conditions. Expressions of six biofilm-related genes (ALS1, ALS3, BCR1, EFG1, TEC1, and UME6 in C. albicans and corresponding orthologs in C. tropicalis) in biofilms co-incubated with CFSs were analyzed using quantitative real-time PCR. When compared to untreated control, the expressions of ALS1, ALS3, EFG1, and TEC1 genes were downregulated in C. albicans biofilm. In C. tropicalis biofilms, ALS3 and UME6 were downregulated while TEC1 was upregulated. Taken together, the L. rhamnosus and L. plantarum strains demonstrated an inhibitory effect, which is likely mediated by the metabolites secreted into culture medium, on filamentation and biofilm formation of C. albicans and C. tropicalis. Our finding suggested an alternative to antifungals for controlling Candida biofilm.}, }
@article {pmid36859622, year = {2023}, author = {Sasaki, H and Kurakado, S and Matsumoto, Y and Yoshino, Y and Sugita, T and Koyama, K and Kinoshita, K}, title = {Enniatins from a marine-derived fungus Fusarium sp. inhibit biofilm formation by the pathogenic fungus Candida albicans.}, journal = {Journal of natural medicines}, volume = {}, number = {}, pages = {}, pmid = {36859622}, issn = {1861-0293}, abstract = {Candidemia is a life-threatening disease common in immunocompromised patients, and is generally caused by the pathogenic fungus Candida albicans. C. albicans can change morphology from yeast to hyphae, forming biofilms on medical devices. Biofilm formation contributes to the virulence and drug tolerance of C. albicans, and thus compounds that suppress this morphological change and biofilm formation are effective for treating and preventing candidemia. Marine organisms produce biologically active and structurally diverse secondary metabolites that are promising lead compounds for treating numerous diseases. In this study, we explored marine-derived fungus metabolites that can inhibit morphological change and biofilm formation by C. albicans. Enniatin B (1), B1 (2), A1 (3), D (4), and E (5), visoltricin (6), ergosterol peroxide (7), 9,11-dehydroergosterol peroxide (8), and 3β,5α,9α-trihydroxyergosta-7,22-dien-6-one (9) were isolated from the marine-derived fungus Fusarium sp. Compounds 1-5 and 8 exhibited inhibitory activity against hyphal formation by C. albicans, and compounds 1-3 and 8 inhibited biofilm formation by C. albicans. Furthermore, compounds 1-3 decreased cell surface hydrophobicity and expression of the hypha-specific gene HWP1 in C. albicans. Compound 1 was obtained in the highest yield. An in vivo evaluation system using silkworms pierced with polyurethane fibers (a medical device substrate) showed that compound 1 inhibited biofilm formation by C. albicans in vivo. These results indicate that enniatins could be lead compounds for therapeutic agents for biofilm infections by C. albicans.}, }
@article {pmid36858631, year = {2023}, author = {Yamane, K and Niki, M and Tsubouchi, T and Watanabe, T and Asai, K and Oinuma, KI and Sakiyama, A and Saren, C and Matsumoto, Y and Makimura, K and Kaneko, Y and Kawaguchi, T}, title = {A Culture Supernatant from an Actinomycete sp. Affects Biofilm Formation and Virulence Expression of Candida auris.}, journal = {Medical mycology journal}, volume = {64}, number = {1}, pages = {7-17}, doi = {10.3314/mmj.22-00026}, pmid = {36858631}, issn = {1882-0476}, abstract = {The multidrug-resistant pathogen Candida auris is characterized by its aggregation under certain conditions, which affects its biofilm formation, drug susceptibility, and pathogenicity. Although the innate tendency to aggregate depends on the strain, the mechanism regulating C. auris aggregation remains unclear. We found that the culture supernatant from one of the 95 Actinomyces strains isolated from a deep-sea environment (IMAs2016D-66) inhibited C. auris aggregation. The cells grown in the presence of IMAs2016D-66 exhibited reduced hydrophobicity, biofilm formation, and enhanced proteolytic activity. In addition, the efflux pump activity of the fluconazole-resistant C. auris strain LSEM 3673 was stimulated by IMAs2016D-66, whereas no significant change was observed in the fluconazole-susceptible strain LSEM 0643. As the relationship between aggregative tendency and virulence in C. auris is still unclear, IMAs2016D-66 can serve as a tool for investigating regulatory mechanisms of phenotype switching and virulence expression of C. auris. Understanding of phenotype switching may help us not only to understand the pathogenicity of C. auris, but also to design new drugs that target the molecules regulating virulence factors.}, }
@article {pmid36855815, year = {2023}, author = {Singha, R and Aggarwal, R and Sanyal, K}, title = {Negative regulation of biofilm development by the CUG-Ser1 clade-specific histone H3 variant is dependent on the canonical histone chaperone CAF-1 complex in Candida albicans.}, journal = {Molecular microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1111/mmi.15050}, pmid = {36855815}, issn = {1365-2958}, abstract = {The CUG-Ser1 clade-specific histone H3 variant (H3V[CTG]) has been reported to be a negative regulator of planktonic to biofilm growth transition in Candida albicans. The preferential binding of H3V[CTG] at the biofilm gene promoters makes chromatin repressive for biofilm-mode of growth. The two evolutionarily conserved chaperone complexes involved in incorporating histone H3 are CAF-1 and HIRA. In this study, we sought to identify the chaperone complex(es) involved in loading H3V[CTG] . We demonstrate that C. albicans cells lacking either Cac1 or Cac2 subunit of the CAF-1 chaperone complex, exhibit a hyper-filamentation phenotype on solid surfaces and form more robust biofilms than wild type cells, thereby mimicking the phenotype of the H3V[CTG] null mutant. None of the subunits of the HIRA chaperone complex shows any significant difference in biofilm growth as compared to the wild type. The occupancy of H3V[CTG] is found to be significantly reduced at the promoters of biofilm genes in the absence of CAF-1 subunits. Hence, we provide evidence that CAF-1, a chaperone known to load canonical histone H3 in mammalian cells, is involved in chaperoning of variant histone H3V[CTG] at the biofilm gene promoters in C. albicans. Our findings also illustrate the acquisition of an unconventional role of the CAF-1 chaperone complex in morphogenesis in C. albicans.}, }
@article {pmid36855334, year = {2023}, author = {Chan, RK and Nuutila, K and Mathew-Steiner, SS and Diaz, V and Anselmo, K and Batchinsky, M and Carlsson, AH and Ghosh, N and Sen, CK and Roy, S}, title = {A Prospective, Randomized, Controlled Study to Evaluate the Effectiveness of a Fabric-based Wireless Electroceutical Dressing Compared to Standard of Care Treatment Against Acute Trauma and Burn Wound Biofilm Infection.}, journal = {Advances in wound care}, volume = {}, number = {}, pages = {}, doi = {10.1089/wound.2023.0007}, pmid = {36855334}, issn = {2162-1918}, abstract = {OBJECTIVE: Despite advances in the use of topical and parenteral antimicrobial therapy and the practice of early tangential burn-wound excision to manage bacterial load, 60% of the mortality from burns is attributed to bacterial biofilm infection. A low electric field (~1V) generated by the novel FDA-cleared wireless electroceutical dressing (WED) was previously shown to significantly prevent and disrupt burn biofilm infection in preclinical studies. Based on this observation, the purpose of this clinical trial was to evaluate the efficacy of the WED dressing powered by a silver- zinc electro-couple in the prevention and disruption of biofilm infection.<br><br>APPROACH: A prospective, randomized, controlled, single center clinical trial was performed to evaluate the efficacy of the WED compared to standard of care (SoC) dressing to treat biofilms. Burn wounds were randomized to receive either SoC or WED. Biopsies were collected on days 0 and 7 for histology, scanning electron microscopy (SEM) examination of biofilm and for quantitative bacteriological analyses.<br><br>RESULTS: In total, 38 subjects were enrolled in the study. In 52% of the WED treated wounds, little to no biofilm could be detected by SEM. WED significantly lowered or prevented increase of biofilm in all wounds compared to the pair matched SoC treated wounds.<br><br>INNOVATION: WED is a simple, easy, and rapid method to protect the wound, while also inhibiting infection. It is activated by a moist environment and the electrical field induces transient and micro molar amounts of superoxide anion radicals that will prevent bacterial growth.<br><br>CONCLUSION: WED decreased biofilm infection better when compared to SoC.}, }
@article {pmid36854956, year = {2023}, author = {Ivanova, LA and Egorov, VV and Zabrodskaya, YA and Shaldzhyan, AA and Baranchikov, AY and Tsvigun, NV and Lykholay, AN and Yapryntsev, AD and Lebedev, DV and Kulminskaya, AA}, title = {Matrix is everywhere: extracellular DNA is a link between biofilm and mineralization in Bacillus cereus planktonic lifestyle.}, journal = {NPJ biofilms and microbiomes}, volume = {9}, number = {1}, pages = {9}, pmid = {36854956}, issn = {2055-5008}, abstract = {To date, the mechanisms of biomineralization induced by bacterial cells in the context of biofilm formation remain the subject of intensive studies. In this study, we analyzed the influence of the medium components on the induction of CaCO3 precipitation by the Bacillus cereus cells and composition of the extracellular matrix (ECM) formed in the submerged culture. While the accumulation of extracellular polysaccharides and amyloids appeared to be independent of the presence of calcium and urea during the growth, the accumulation of extracellular DNA (eDNA), as well as precipitation of calcium carbonate, required the presence of both ingredients in the medium. Removal of eDNA, which was sensitive to treatment by DNase, did not affect other matrix components but resulted in disruption of cell network formation and a sixfold decrease in the precipitate yield. An experiment with a cell-free system confirmed the acceleration of mineral formation after the addition of exogenous salmon sperm DNA. The observed pathway for the formation of CaCO3 minerals in B. cereus planktonic culture included a production of exopolysaccharides and negatively charged eDNA lattice promoting local Ca[2+] supersaturation, which, together with an increase in the concentration of carbonate ions due to pH rise, resulted in the formation of an insoluble precipitate of calcium carbonate. Precipitation of amorphous CaCO3 on eDNA matrix was followed by crystal formation via the ACC-vaterite-calcite/aragonite pathway and further formation of larger mineral aggregates in complex with extracellular polymeric substances. Taken together, our data showed that DNA in extracellular matrix is an essential factor for triggering the biomineralization in B. cereus planktonic culture.}, }
@article {pmid36853819, year = {2023}, author = {Morselli, S and Salvo, M and Foschi, C and Lazzarotto, T and Ambretti, S and Marangoni, A}, title = {Characterization of Gardnerella vaginalis isolates: correlations among clades, biofilm formation and cytokine stimulation.}, journal = {The new microbiologica}, volume = {46}, number = {1}, pages = {56-59}, pmid = {36853819}, issn = {1121-7138}, abstract = {We characterized 61 Gardnerella vaginalis (GV) strains isolated from women with bacterial vaginosis. GV clade 1 was the most commonly found (52.5%), followed by clade 4 (36.1%). All the strains were susceptible to ampicillin and clindamycin, whereas 96.7% and 6.6% of strains showed metronidazole and tetracycline resistance, respectively. Isolates within clade 4 tended to possess the highest ability to form biofilm. Strains resistant to metronidazole and tetracycline were all intermediate or high biofilm producers. All GV clades significantly upregulated the production of pro-inflammatory cytokines by HeLa cells, especially IL-8 and IL-6. Clade 4 induced a significantly higher production of IL-1β compared to other clades.}, }
@article {pmid36853055, year = {2023}, author = {Bianchini Fulindi, R and Domingues Rodrigues, J and Lemos Barbosa, TW and Goncalves Garcia, AD and de Almeida La Porta, F and Pratavieira, S and Chiavacci, LA and Pessoa Araújo Junior, J and da Costa, PI and Martinez, LR}, title = {Zinc-Based Nanoparticles Reduce Bacterial Biofilm Formation.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0483122}, doi = {10.1128/spectrum.04831-22}, pmid = {36853055}, issn = {2165-0497}, abstract = {Biofilm formation is important for microbial survival in hostile environments and a phenotype that provides microorganisms with antimicrobial resistance. Zinc oxide (ZnO) and Zinc sulfide (ZnS) nanoparticles (NPs) present potential antimicrobial properties for biomedical and food industry applications. Here, we aimed to analyze, for the first time, the bactericidal and antibiofilm activity of ZnS NPs against Staphylococcus aureus, Klebsiella oxytoca, and Pseudomonas aeruginosa, all medically important bacteria in developed countries. We compared ZnS NPs antimicrobial activity to ZnO NPs, which have been extensively studied. Using the colorimetric XTT reduction assay to observe the metabolic activity of bacterial cells and the crystal violet assay to measure biofilm mass, we demonstrated that ZnS and ZnO had similar efficacy in killing planktonic bacterial cells and reducing biofilm formation, with S. aureus being more susceptible to both therapeutics than K. oxytoca and P. aeruginosa. Crystal violet staining and confocal microscopy validated that Zn NPs inhibit biofilm formation and cause architectural damage. Our findings provide proof of principle that ZnS NPs have antibiofilm activity, and can be potentially used in medical and food industry applications, such as treatment of wound infections or package coating for food preservation. IMPORTANCE Zinc (Zn)-based nanoparticles (NPs) can be potentially used in medical and food preservation applications. As proof of principle, we investigated the bactericidal and antibiofilm activity of zinc oxide (ZnO) and zinc sulfide (ZnS) NPs against medically important bacteria. Zn-based NPs were similarly effective in killing planktonic and biofilm-associated Staphylococcus aureus, Klebsiella oxytoca, and Pseudomonas aeruginosa cells. However, S. aureus was more susceptible to these investigational therapeutics. Although further studies are warranted, our findings suggest the possibility of future use of Zn-based NPs in the treatment of skin infections or preservation of food.}, }
@article {pmid36850031, year = {2023}, author = {Li, Q and Liu, Q and Wang, Z and Zhang, X and Ma, R and Hu, X and Mei, J and Su, Z and Zhu, W and Zhu, C}, title = {Biofilm Homeostasis Interference Therapy via [1] O2 -Sensitized Hyperthermia and Immune Microenvironment Re-Rousing for Biofilm-Associated Infections Elimination.}, journal = {Small (Weinheim an der Bergstrasse, Germany)}, volume = {}, number = {}, pages = {e2300592}, doi = {10.1002/smll.202300592}, pmid = {36850031}, issn = {1613-6829}, abstract = {The recurrence of biofilm-associated infections (BAIs) remains high after implant-associated surgery. Biofilms on the implant surface reportedly shelter bacteria from antibiotics and evade innate immune defenses. Moreover, little is currently known about eliminating residual bacteria that can induce biofilm reinfection. Herein, novel "interference-regulation strategy" based on bovine serum albumin-iridium oxide nanoparticles (BIONPs) as biofilm homeostasis interrupter and immunomodulator via singlet oxygen ([1] O2)-sensitized mild hyperthermia for combating BAIs is reported. The catalase-like BIONPs convert abundant H2 O2 inside the biofilm-microenvironment (BME) to sufficient oxygen gas (O2), which can efficiently enhance the generation of [1] O2 under near-infrared irradiation. The [1] O2 -induced biofilm homeostasis disturbance (e.g., sigB, groEL, agr-A, icaD, eDNA) can disrupt the sophisticated defense system of biofilm, further enhancing the sensitivity of biofilms to mild hyperthermia. Moreover, the mild hyperthermia-induced bacterial membrane disintegration results in protein leakage and [1] O2 penetration to kill bacteria inside the biofilm. Subsequently, BIONPs-induced immunosuppressive microenvironment re-rousing successfully re-polarizes macrophages to pro-inflammatory M1 phenotype in vivo to devour residual biofilm and prevent biofilm reconstruction. Collectively, this [1] O2 -sensitized mild hyperthermia can yield great refractory BAIs treatment via biofilm homeostasis interference, mild-hyperthermia, and immunotherapy, providing a novel and effective anti-biofilm strategy.}, }
@article {pmid36849163, year = {2023}, author = {Xiong, Q and Qu, J and Zhao, R and Chen, Y and Li, Y and Xu, W and Pan, B and Jin, P and Zheng, Z}, title = {Fabrication of a novel polyurethane foam-alginate-zeolite hydrogel and subsequent KSND bacteria encapsulation: evidence of accelerated biofilm colonisation and enhanced nitrogen removal efficiency.}, journal = {Letters in applied microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/lambio/ovac054}, pmid = {36849163}, issn = {1472-765X}, abstract = {Biofilms are used widely to remove nitrogen from wastewater; however, most biofilm carriers (i.e. polyurethane foam, PUF) are hydrophobic organic materials with millimetre-scale apertures, ineffective attachment, and unstable colonisation of microorganisms. To address these limitations, hydrophilic sodium alginate (SA) mixed with zeolite powder (Zeo) was crosslinked in PUF to form a micro-scale hydrogel (PAS) with a well-organised and reticular cellular structure. Scanning electron microscopy revealed that immobilised cells were entrapped in the interior of hydrogel filaments and rapidly formed a stable biofilm on the surface. The biofilm generated was 10.3-fold greater than the film developed on PUF. Kinetics and isotherm studies revealed that the as-developed carrier, because of the presence of Zeo, effectively improved the adsorption of NH4+-N by 53%. The PAS carrier achieved total nitrogen removal in excess of 86% for low carbon-to-nitrogen ratio wastewater treated for 30 d, indicating that this novel modification-encapsulation technology has potential for wastewater treatment.}, }
@article {pmid36848732, year = {2023}, author = {Brunswick, P and Blajkevitch, O and Filewood, T and Kent, E and Drever, MC and Elner, RW and Shang, D}, title = {Long chain fatty acids analysis of intertidal biofilm by direct injection liquid chromatography time of flight mass spectrometry.}, journal = {Journal of chromatography. A}, volume = {1693}, number = {}, pages = {463870}, doi = {10.1016/j.chroma.2023.463870}, pmid = {36848732}, issn = {1873-3778}, abstract = {The critical importance of mono- and polyunsaturated fatty acids (FAs) in a variety of biological functions, including animal nutrition and as an environmental stress monitor, is well recognized. However, while methods exist for monitoring of fatty acids, few are specific either to the profile of a microphytobenthos matrix or practical in application to multiple, diverse intertidal biofilm sample sets. In the current study, a sensitive liquid chromatography (LC) quadrupole time of flight mass spectrometry (QTOF) method was developed for the quantitative analysis of 31 FAs specific to intertidal biofilm, a thin mucilaginous layer of microalgae, bacteria, and other organisms on the surface of coastal mudflats, which provide a rich source of FAs for migratory birds. Preliminary screening of diverse biofilm samples collected from shorebird feeding grounds highlighted eight saturated (SFA), seven monounsaturated (MUFA), and sixteen polyunsaturated FAs (PUFA) that were selected for analysis. Improved method detection limits in the range 0.3-2.6 ngmL[-1] were achieved, excepting for stearic acid at 10.6 ngmL[-1]. These excellent results were obtained without use of complex sample extraction and clean-up procedures undertaken by other published methods. An alkaline matrix of dilute aqueous ammonium hydroxide with methanol was shown to be selective for extraction and stability of the more hydrophilic fatty acid components. The direct injection method showed excellent precision and accuracy both during validation and application to hundreds of real-world intertidal biofilm samples from the Fraser River estuary (British Columbia, Canada) and other areas of the region frequented by shoreline birds.}, }
@article {pmid36847907, year = {2023}, author = {Fatima, T and Fatima, Z and Hameed, S}, title = {Abrogation of efflux pump activity, biofilm formation, and immune escape by candidacidal geraniol in emerging superbug, Candida auris.}, journal = {International microbiology : the official journal of the Spanish Society for Microbiology}, volume = {}, number = {}, pages = {}, pmid = {36847907}, issn = {1618-1905}, abstract = {During the last decade, Candida auris emerged as a threatening human fungal pathogen that notably caused outbreaks around the globe with high mortality. Considering C. auris species as newly discovered fungi, the evolutionary features remain elusive. The antifungal resistance which is a norm in C. auris underlines the need for innovative therapeutic options. ATP Binding Cassette (ABC) superfamily efflux pumps overexpression and biofilms are known to be major contributors to multidrug resistance (MDR) in C. auris. Therefore, herein, we investigated the antifungal potential of geraniol (Ger) as a promising natural compound in the fight against MDR C. auris. Our experiments proved that Ger was fungicidal in nature and impaired rhodamine 6G (R6G) efflux, confirming the specific effect on ABC transporters. Kinetic studies unravelled the competitive mode of inhibition by Ger for R6G efflux since the apparent Km increased with no change in Vmax value. Mechanistic insights also revealed that Ger depleted ergosterol content in C. auris. Furthermore, Ger led to inhibition in biofilm formation as evident from crystal violet staining, biofilm metabolic and biomass measurements. Additionally, enhanced survival of Caenorhabditis elegans model after C. auris infection demonstrated the in vivo efficacy of Ger. Lastly, the in vivo efficacy was confirmed from a THP-1 cell line model which depicted enhanced macrophage-mediated killing in the presence of Ger. Modulation of C. auris efflux pump activity and biofilm formation by Ger represents a promising approach to combat MDR. Together, this study demonstrated the potential therapeutic insights of Ger as a promising addition to the antifungal armamentarium required to treat emerging and resistant C. auris.}, }
@article {pmid36847713, year = {2023}, author = {Bravo, E and Serrano, B and Ribeiro-Vidal, H and Virto, L and Sanz Sánchez, I and Herrera, D and Sanz, M}, title = {Biofilm formation on dental implants with a hybrid surface microtopography. An in vitro study in a validated multispecies dynamic biofilm model.}, journal = {Clinical oral implants research}, volume = {}, number = {}, pages = {}, doi = {10.1111/clr.14054}, pmid = {36847713}, issn = {1600-0501}, abstract = {OBJECTIVES: To qualitatively and quantitatively evaluate biofilm formation on hybrid titanium implants (HS), with moderately rough and turned surface topographies.<br><br>MATERIALS AND METHODS: A validated dynamic in vitro multi-species biofilm model, based on bacterial growth under flow and shear conditions resembling the oral cavity, was used to evaluate biofilm formation on the tested implant surfaces. Scanning Electron Microscope (SEM) and Confocal Laser Scanning Microscopy (CLSM) were used to compare the biofilm structure and microbial biomass deposited on either the moderately rough or the turned surface of HS. Quantitative polymerase chain reaction (qPCR) was used to evaluate the total bacterial counts and counts of each specific bacterium in biofilms formed on implants with either the moderately rough or the turned surfaces, as in the hybrid titanium implants, after 24, 48 and 72 h. A general linear model was applied to compare the CLSM and qPCR results between the tested implant surfaces.<br><br>RESULTS: A significantly higher bacterial biomass grew on the moderately rough implant surfaces, compared to the turned surface area of HS implants (p<0.05), at all incubation times, as evidenced with both CLSM and SEM. qPCR analysis also demonstrated an important increase in the total and specific bacterial counts in moderately rough surface implants at the three incubation times.<br><br>CONCLUSIONS: Implant surface topography (moderately rough versus turned) significantly influenced in vitro biofilm formation in terms of biofilm structure, bacterial biomass and quantity of the specific species selected for the model used.}, }
@article {pmid36847700, year = {2023}, author = {Virto, L and Odeh, V and Garcia-Quismondo, E and Herrera, D and Palma, J and Tamimi, F and Sanz, M}, title = {Electrochemical decontamination of titanium dental implants. An in vitro biofilm model study.}, journal = {Clinical oral implants research}, volume = {}, number = {}, pages = {}, doi = {10.1111/clr.14055}, pmid = {36847700}, issn = {1600-0501}, abstract = {OBJECTIVES: To study the effect of electrochemical treatment on biofilms developed on titanium dental implants, using a six-species in vitro model simulating subgingival oral biofilms.<br><br>MATERIALS AND METHODS: Direct electrical current (DC) of 0.75V, 1.5V and 3V (anodic polarization, oxidation processes) and of -0.75V, -1.5V and -3V (cathodic polarization, reduction processes) was applied between the working and the reference electrodes for 5 minutes on titanium dental implants, which have been previously inoculated with a multispecies biofilm. This electrical application consisted of a three-electrode system where the implant was the working electrode, a platinum mesh was the counter electrode, and an Ag/AgCl electrode was the reference. The effect of the electrical application on the biofilm structure and bacterial composition was evaluated by scanning electron microscopy and quantitative polymerase chain reaction. A generalized linear model was applied to study the bactericidal effect of the proposed treatment.<br><br>RESULTS: The electrochemical construct at 3V and -3V settings significantly reduced total bacterial counts (p<0.05) from 3.15 x 10[6] to 1.85 x 10[5] and 2.92 x 10[4] live bacteria/mL respectively. Fusobacterium nucleatum was the most affected species in terms of reduction in concentration. The 0.75V and -0.75V treatments had no effect on the biofilm.<br><br>CONCLUSION: Electrochemical treatments had a bactericidal effect on this multispecies subgingival in vitro biofilm model, being the reduction more effective than the oxidative treatment.}, }
@article {pmid36847543, year = {2023}, author = {Dong, J and Liu, L and Chen, L and Xiang, Y and Wang, Y and Zhao, Y}, title = {The Coexistence of Bacterial Species Restructures Biofilm Architecture and Increases Tolerance to Antimicrobial Agents.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0358122}, doi = {10.1128/spectrum.03581-22}, pmid = {36847543}, issn = {2165-0497}, abstract = {Chronic infections caused by polymicrobial biofilms are often difficult to treat effectively, partially due to the elevated tolerance of polymicrobial biofilms to antimicrobial treatments. It is known that interspecific interactions influence polymicrobial biofilm formation. However, the underlying role of the coexistence of bacterial species in polymicrobial biofilm formation is not fully understood. Here, we investigated the effect of the coexistence of Enterococcus faecalis, Escherichia coli O157:H7, and Salmonella enteritidis on triple-species biofilm formation. Our results demonstrated that the coexistence of these three species enhanced the biofilm biomass and led to restructuring of the biofilm into a tower-like architecture. Furthermore, the proportions of polysaccharides, proteins, and eDNAs in the extracellular matrix (ECM) composition of the triple-species biofilm were significantly changed compared to those in the E. faecalis mono-species biofilm. Finally, we analyzed the transcriptomic profile of E. faecalis in response to coexistence with E. coli and S. enteritidis in the triple-species biofilm. The results suggested that E. faecalis established dominance and restructured the triple-species biofilm by enhancing nutrient transport and biosynthesis of amino acids, upregulating central carbon metabolism, manipulating the microenvironment through "biological weapons," and activating versatile stress response regulators. Together, the results of this pilot study reveal the nature of E. faecalis-harboring triple-species biofilms with a static biofilm model and provide novel insights for further understanding interspecies interactions and the clinical treatment of polymicrobial biofilms. IMPORTANCE Bacterial biofilms possess distinct community properties that affect various aspects of our daily lives. In particular, biofilms exhibit increased tolerance to chemical disinfectants, antimicrobial agents, and host immune responses. Multispecies biofilms are undoubtedly the dominant form of biofilms in nature. Thus, there is a pressing need for more research directed at delineating the nature of multispecies biofilms and the effects of the properties on the development and survival of the biofilm community. Here, we address the effects of the coexistence of Enterococcus faecalis, Escherichia coli, and Salmonella enteritidis on triple-species biofilm formation with a static model. In combination with transcriptomic analyses, this pilot study explores the potential underlying mechanisms that lead to the dominance of E. faecalis in triple-species biofilms. Our findings provide novel insights into the nature of triple-species biofilms and indicate that the composition of multispecies biofilms should be a key consideration when determining antimicrobial treatments.}, }
@article {pmid36847490, year = {2023}, author = {Long, DR and Penewit, K and Lo, HY and Almazan, J and Holmes, EA and Bryan, AB and Wolter, DJ and Lewis, JD and Waalkes, A and Salipante, SJ}, title = {In Vitro Selection Identifies Staphylococcus aureus Genes Influencing Biofilm Formation.}, journal = {Infection and immunity}, volume = {}, number = {}, pages = {e0053822}, doi = {10.1128/iai.00538-22}, pmid = {36847490}, issn = {1098-5522}, abstract = {Staphylococcus aureus generates biofilms during many chronic human infections, which contributes to its growth and persistence in the host. Multiple genes and pathways necessary for S. aureus biofilm production have been identified, but knowledge is incomplete, and little is known about spontaneous mutations that increase biofilm formation as infection progresses. Here, we performed in vitro selection of four S. aureus laboratory strains (ATCC 29213, JE2, N315, and Newman) to identify mutations associated with enhanced biofilm production. Biofilm formation increased in passaged isolates from all strains, exhibiting from 1.2- to 5-fold the capacity of parental lines. Whole-genome sequencing identified nonsynonymous mutations affecting 23 candidate genes and a genomic duplication encompassing sigB. Six candidate genes significantly impacted biofilm formation as isogenic transposon knockouts: three were previously reported to impact S. aureus biofilm formation (icaR, spdC, and codY), while the remaining three (manA, narH, and fruB) were newly implicated by this study. Plasmid-mediated genetic complementation of manA, narH, and fruB transposon mutants corrected biofilm deficiencies, with high-level expression of manA and fruB further enhancing biofilm formation over basal levels. This work recognizes genes not previously identified as contributing to biofilm formation in S. aureus and reveals genetic changes able to augment biofilm production by that organism.}, }
@article {pmid36846774, year = {2023}, author = {Zhang, M and Xue, X and Li, X and Wu, Q and Zhang, T and Yang, W and Hu, L and Zhou, D and Lu, R and Zhang, Y}, title = {QsvR and OpaR coordinately repress biofilm formation by Vibrio parahaemolyticus.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1079653}, pmid = {36846774}, issn = {1664-302X}, abstract = {Mature biofilm formation by Vibrio parahaemolyticus requires exopolysaccharide (EPS), type IV pili, and capsular polysaccharide (CPS). Production of each is strictly regulated by various control pathways including quorum sensing (QS) and bis-(3'-5')-cyclic di-GMP (c-di-GMP). QsvR, an AraC-type regulator, integrates into the QS regulatory cascade via direct control of the transcription of the master QS regulators, AphA and OpaR. Deletion of qsvR in wild-type or opaR mutant backgrounds altered the biofilm formation by V. parahaemolyticus, suggesting that QsvR may coordinate with OpaR to control biofilm formation. Herein, we demonstrated both QsvR and OpaR repressed biofilm-associated phenotypes, c-di-GMP metabolism, and the formation of V. parahaemolyticus translucent (TR) colonies. QsvR restored the biofilm-associated phenotypic changes caused by opaR mutation, and vice versa. In addition, QsvR and OpaR worked coordinately to regulate the transcription of EPS-associated genes, type IV pili genes, CPS genes and c-di-GMP metabolism-related genes. These results demonstrated how QsvR works with the QS system to regulate biofilm formation by precisely controlling the transcription of multiple biofilm formation-associated genes in V. parahaemolyticus.}, }
@article {pmid36846753, year = {2023}, author = {Li, L and Yu, T and Yuan, L and Doulgeraki, AI and Iseppi, R}, title = {Corrigendum: Editorial: Biofilm formation and quorum sensing of foodborne microorganism.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1144058}, doi = {10.3389/fmicb.2023.1144058}, pmid = {36846753}, issn = {1664-302X}, abstract = {[This corrects the article DOI: 10.3389/fmicb.2022.1107603.].}, }
@article {pmid36845825, year = {2023}, author = {De Bleeckere, A and Van den Bossche, S and De Sutter, PJ and Beirens, T and Crabbé, A and Coenye, T}, title = {High throughput determination of the biofilm prevention concentration for Pseudomonas aeruginosa biofilms using a synthetic cystic fibrosis sputum medium.}, journal = {Biofilm}, volume = {5}, number = {}, pages = {100106}, pmid = {36845825}, issn = {2590-2075}, abstract = {The presence of Pseudomonas aeruginosa biofilms in cystic fibrosis (CF) patients suffering from chronic lung infections contributes to the failure of antimicrobial therapy. Conventionally, the minimal inhibitory concentration (MIC) is determined to assess the antimicrobial susceptibility of a pathogen, however this parameter fails to predict success in treating biofilm-associated infections. In the present study we developed a high throughput method to determine the antimicrobial concentration required to prevent P. aeruginosa biofilm formation, using a synthetic cystic fibrosis sputum medium (SCFM2). Biofilms were grown in SCFM2 for 24 h in the presence of antibiotics (tobramycin, ciprofloxacin or colistin), whereafter biofilms were disrupted and a resazurin staining was used to quantify the number of surviving metabolically active cells. In parallel, the content of all wells was plated to determine the number of colony forming units (CFU). Biofilm preventing concentrations (BPCs) were compared to MICs and minimal bactericidal concentrations (MBCs) determined according to EUCAST guidelines. Correlations between the resazurin-derived fluorescence and CFU counts were assessed with Kendall's Tau Rank tests. A significant correlation between fluorescence and CFU counts was observed for 9 out of 10 strains investigated, suggesting the fluorometric assay is a reliable alternative to plating for most P. aeruginosa isolates to determine biofilm susceptibility in relevant conditions. For all isolates a clear difference between MICs and BPCs of all three antibiotics was observed, with the BPCs being consistently higher than the MICs. Additionally, the extent of this difference appeared to be antibiotic-dependent. Our findings suggest that this high throughput assay could be a valuable addition to evaluate the antimicrobial susceptibility in P. aeruginosa biofilms in the context of CF.}, }
@article {pmid36845188, year = {2023}, author = {Cao, LY and Liu, CG and Yang, SH and Bai, FW}, title = {Regulation of biofilm formation in Zymomonas mobilis to enhance stress tolerance by heterologous expression of pfs and luxS.}, journal = {Frontiers in bioengineering and biotechnology}, volume = {11}, number = {}, pages = {1130405}, pmid = {36845188}, issn = {2296-4185}, abstract = {Zymomonas mobilis is a potential alternative of Saccharomyces cerevisiae to produce cellulosic ethanol with strengths in cofactor balance, but its lower tolerance to inhibitors in the lignocellulosic hydrolysate restricts the application. Although biofilm can improve bacteria stress tolerance, regulating biofilm formation in Z. mobilis is still a challenge. In this work, we constructed a pathway by heterologous expressing pfs and luxS from Escherichia coli in Z. mobilis to produce AI-2 (autoinducer 2), a universal quorum-sensing signal molecule, to control cell morphology for enhancing stress tolerance. Unexpectedly, the results suggested that neither endogenous AI-2 nor exogenous AI-2 promoted biofilm formation, while heterologous expression of pfs can significantly raise biofilm. Therefore, we proposed that the main factor in assisting biofilm formation was the product accumulated due to heterologous expression of pfs, like methylated DNA. Consequently, ZM4::pfs produced more biofilm, which presented an enhanced tolerance to acetic acid. All these findings provide a novel strategy to improve the stress tolerance of Z. mobilis by enhancing biofilm formation for efficient production of lignocellulosic ethanol and other value-added chemical products.}, }
@article {pmid36844532, year = {2023}, author = {Hassan, N and Farooq, U and Das, AK and Sharma, K and Mirza, MA and Fatima, S and Singh, O and Ansari, MJ and Ali, A and Iqbal, Z}, title = {In Silico Guided Nanoformulation Strategy for Circumvention of Candida albicans Biofilm for Effective Therapy of Candidal Vulvovaginitis.}, journal = {ACS omega}, volume = {8}, number = {7}, pages = {6918-6930}, pmid = {36844532}, issn = {2470-1343}, abstract = {Candidal vulvovaginitis involving multispecies of Candida and epithelium-bound biofilm poses a drug-resistant pharmacotherapeutic challenge. The present study aims for a disease-specific predominant causative organism resolution for the development of a tailored vaginal drug delivery system. The proposed work fabricates a luliconazole-loaded nanostructured lipid carrier-based transvaginal gel for combating Candida albicans biofilm and disease amelioration. The interaction and binding affinity of luliconazole against the proteins of C. albicans and biofilm were assessed using in silico tools. A systematic QbD analysis was followed to prepare the proposed nanogel using a modified melt emulsification-ultrasonication-gelling method. The DoE optimization was logically implemented to ascertain the effect of independent process variables (excipients concentration; sonication time) on dependent formulation responses (particle size; polydispersity index; entrapment efficiency). The optimized formulation was characterized for final product suitability. The surface morphology and dimensions were spherical and ≤300 nm, respectively. The flow behavior of an optimized nanogel (semisolid) was non-Newtonian similar to marketed preparation. The texture pattern of a nanogel was firm, consistent, and cohesive. The release kinetic model followed was Higuchi (nanogel) with a % cumulative drug release of 83.97 ± 0.69% in 48 h. The % cumulative drug permeated across a goat vaginal membrane was found to be 53.148 ± 0.62% in 8 h. The skin-safety profile was examined using a vaginal irritation model (in vivo) and histological assessments. The drug and proposed formulation(s) were checked against the pathogenic strains of C. albicans (vaginal clinical isolates) and in vitro established biofilms. The visualization of biofilms was done under a fluorescence microscope revealing mature, inhibited, and eradicated biofilm structures.}, }
@article {pmid36842356, year = {2023}, author = {Sun, KM and Wang, J and Ju, Q and Zhao, Y and Kong, X and Chao, Y and Tian, Y}, title = {The mitigating effects of diatom-bacteria biofilm on coastal harmful algal blooms: A lab-based study concerning species-specific competition and biofilm formation.}, journal = {Journal of environmental management}, volume = {335}, number = {}, pages = {117544}, doi = {10.1016/j.jenvman.2023.117544}, pmid = {36842356}, issn = {1095-8630}, abstract = {Harmful algal blooms (HABs) in coastal areas severely affected the health of ecosystem and human beings. The HABs control by biological methods, especially for biofilms, has been research hotspots in freshwater ecosystem. However, the biofilm-relating control of HABs in marine environment was very limited. In the present study, we found the population growth of two harmful algal species, Prorocentrum obtusidens Schiller (formerly P. donghaiense Lu) and Heterosigma akashiwo, were inhibited by a diatom-bacteria biofilm. The highest inhibitory rate was 79.6 ± 2.1% for P. obtusidens when co-cultured with biofilm suspension, and was 88.6 ± 5.8% for H. akashiwo when co-cultured with the biofilm filtrate without nutrient replenishment. When nitrate and phosphate were added, the inhibition rate for P. obtusidens was 72.3 ± 2.0%, but the population inhibition was not found in H. akashiwo. It suggested that P. obtusidens was mainly inhibited via interference competition, while the inhibition of H. akashiwo was resulted from exploitation competition. We further investigated the role of fatty acids for the interference competition in P. obtusidens, and found that fatty acids at their environmental-relevance concentrations can inhibit the photosynthetic capacity of P. obtusidens, but cannot inhibit the population growth. The community of biofilm shifted, and was finally dominated by the photoheterotrophic bacterium Dinoroseobacter shibae, and the diatom Fistulifera sp. with relative abundance of higher than 90%. Our study indicated that the diatom-bacteria biofilm was likely the candidate for the HABs control in marine environment. D. shibae and Fistulifera sp. were probably the effective species in the biofilm.}, }
@article {pmid36841082, year = {2023}, author = {Adedoyin, FT and Sridhar, BBM and Rosenzweig, JA}, title = {Impact of metal exposure on environmentally isolated Serratia marcescens' growth, oxidative-stress resistance, biofilm formation, and proliferation in eukaryotic co-culture models.}, journal = {Ecotoxicology and environmental safety}, volume = {253}, number = {}, pages = {114677}, doi = {10.1016/j.ecoenv.2023.114677}, pmid = {36841082}, issn = {1090-2414}, abstract = {Environmental metals can be noxious to the surrounding biota, indirectly impact freshwater habitats, and also impact microbiological communities. In this study, zinc (Zn) (55.5 mg/kg), manganese (Mn) (863.4 mg/kg) and lead (Pb) (17.5 mg/kg) levels measured in Houston watershed flood plain soil samples were higher than environmental agencies' thresholds. To investigate the effects of metal exposures, an environmentally isolated Serratia marcescens (SME), etiological agent of endocarditis and respiratory infections, and its reference strain (SMR) were exposed to Pb, Zn, and Mn, and subsequent oxidative stress responses and biofilm production were measured. Not surprisingly, SME was less sensitive to all 3 metal exposures than was SMR. Interestingly, SME produced increased biofilm and was more resistant to oxidative stress in the presence of Zn and Pb than SMR. In a 6 h lung infection model using BAES-2B cells, SME exhibited greater proliferation than SMR in all metal challenges. Similarly, in our HT29 gut infection model, SME out-proliferated SMR when challenged with Pb and Mn following the 6 h infection. Taken together, SME was better able to withstand environmental stressors than SMR, suggesting increased virulence potential of this opportunistic human pathogen.}, }
@article {pmid36839796, year = {2023}, author = {Aleksandrova, YI and Shurpik, DN and Nazmutdinova, VA and Mostovaya, OA and Subakaeva, EV and Sokolova, EA and Zelenikhin, PV and Stoikov, II}, title = {Toward Pathogenic Biofilm Suppressors: Synthesis of Amino Derivatives of Pillar[5]arene and Supramolecular Assembly with DNA.}, journal = {Pharmaceutics}, volume = {15}, number = {2}, pages = {}, pmid = {36839796}, issn = {1999-4923}, abstract = {New amino derivatives of pillar[5]arene were obtained in three stages with good yields. It was shown that pillar[5]arene containing thiaether and tertiary amino groups formed supramolecular complexes with low molecular weight model DNA. Pillar[5]arene formed complexes with a DNA nucleotide pair at a ratio of 1:2 (macrocycle/DNA base pairs), as demonstrated by UV-visible and fluorescence spectroscopy. The association constants of pillar[5]arene with DNA were lgKass1:1 = 2.38 and lgKass1:2 = 5.07, accordingly. By using dynamic light scattering and transmission electron microscopy, it was established that the interaction of pillar[5]arene containing thiaether and tertiary amino groups (concentration of 10-5 M) with a model nucleic acid led to the formation of stable nanosized macrocycle/DNA associates with an average particle size of 220 nm. It was shown that the obtained compounds did not exhibit a pronounced toxicity toward human adenocarcinoma cells (A549) and bovine lung epithelial cells (LECs). The hypothesis about a possible usage of the synthesized macrocycle for the aggregation of extracellular bacterial DNA in a biofilm matrix was confirmed by the example of St. Aureus. It was found that pillar[5]arene at a concentration of 10[-5] M was able to reduce the thickness of the St. Aureus biofilm by 15%.}, }
@article {pmid36839785, year = {2023}, author = {MubarakAli, D and Arunachalam, K and Lakshmanan, M and Badar, B and Kim, JW and Lee, SY}, title = {Unveiling the Anti-Biofilm Property of Hydroxyapatite on Pseudomonas aeruginosa: Synthesis and Strategy.}, journal = {Pharmaceutics}, volume = {15}, number = {2}, pages = {}, pmid = {36839785}, issn = {1999-4923}, abstract = {Biofilm-related nosocomial infections may cause a wide range of life-threatening infections. In this regard, Pseudomonas aeruginosa biofilm is becoming a serious health burden due to its capability to develop resistance to natural and synthetic drugs. The utilization of nanoparticles that inhibit biofilm formation is one of the major strategies to control infections caused by biofilm-forming pathogens. Hydroxyapatite (HA) is a synthetic ceramic material having properties similar to natural bones. Herein, a co-precipitation method followed by microwave treatment was used to synthesize HA nanoparticles (HANPs). The resulting HANPs were characterized using X-ray diffraction and transmission electron microscopy. Then, their antibiofilm properties against P. aeruginosa ATCC 10145 were examined in vitro. The needle-shaped HANPs were 30 and 90 nm long in width and length, respectively. The synthesized HANPs inhibited the biofilm formation of P. aeruginosa ATCC 10145 in a concentration-dependent manner, which was validated by light and confocal laser scanning microscopy. Hence, this study demonstrated that HANPs could be used to control the biofilm-related infections of P. aeruginosa.}, }
@article {pmid36839583, year = {2023}, author = {Bonsaglia, ECR and Rossi, RS and Latosinski, G and Rossi, BF and Campos, FC and Junior, AF and Pantoja, JCF and Rall, VLM}, title = {Relationship between Biofilm Production and High Somatic Cell Count in Streptococcus agalactiae Isolated from Milk of Cows with Subclinical Mastitis.}, journal = {Pathogens (Basel, Switzerland)}, volume = {12}, number = {2}, pages = {}, doi = {10.3390/pathogens12020311}, pmid = {36839583}, issn = {2076-0817}, abstract = {Streptococcus agalactiae (S. agalactiae) is one of the main agents that causes mastitis in dairy cows, mainly inducing the subclinical form, which is characterized by a high somatic cell count (SCC). The aim of this study was to correlate the increase in SCC caused by S. agalactiae in cows with subclinical mastitis to the presence of genes related to adhesion and invasion in bovine mammary epithelial cells (BMEC) and biofilm formation. Considering the 145 isolates tested, 57.2% presented the capsular type Ia and 42.8% presented type III. We identified the virulence genes among the isolates and determined nine genetic profiles. The most common profile was identified in 69 isolates (47.5%): Ia, fbsA[+], fbsB[-], pI1[-], pI2a[-], pI2b[+], and hylb[+]. All isolates produced biofilm, with 58.6% classified as strong producers, 29% as moderate producers and 12.4% as weak producers. No statistical correlation was found between the presence of virulence genes and increased SCC or biofilm production. However, biological evidence was observed between increased SCC and biofilm production. One isolate from each profile was randomly subjected to adhesion and invasion assays, and all of them adhered to BEMC, but none were able to invade. Our results showed that different genetic profiles do not provide advantages for bacteria to invade BMEC in vitro. In addition, biofilm production appears to be related to high SCC.}, }
@article {pmid36839449, year = {2023}, author = {Kudinova, A and Grishin, A and Grunina, T and Poponova, M and Bulygina, I and Gromova, M and Choudhary, R and Senatov, F and Karyagina, A}, title = {Antibacterial and Anti-Biofilm Properties of Diopside Powder Loaded with Lysostaphin.}, journal = {Pathogens (Basel, Switzerland)}, volume = {12}, number = {2}, pages = {}, doi = {10.3390/pathogens12020177}, pmid = {36839449}, issn = {2076-0817}, abstract = {BACKGROUND: Diopside-based ceramic is a perspective biocompatible material with numerous potential applications in the field of bone prosthetics. Implantable devices and materials are often prone to colonization and biofilm formation by pathogens such as Staphylococcus aureus, which in the case of bone grafting leads to osteomyelitis, an infectious bone and bone marrow injury. To lower the risk of bacterial colonization, implanted materials can be impregnated with antimicrobials. In this work, we loaded the antibacterial enzyme lysostaphin on diopside powder and studied the antibacterial and antibiofilm properties of such material to probe the utility of this approach for diopside-based prosthetic materials.<br><br>METHODS: Diopside powder was synthesized by the solid-state method, lysostaphin was loaded on diopside by adsorption, the release of lysostaphin from diopside was monitored by ELISA, and antibacterial and anti-biofilm activity was assessed by standard microbiological procedures.<br><br>RESULTS AND CONCLUSIONS: Lysostaphin released from diopside powder showed high antibacterial activity against planktonic bacteria and effectively destroyed 24-h staphylococcal biofilms. Diopside-based materials possess a potential for the development of antibacterial bone grafting materials.}, }
@article {pmid36838900, year = {2023}, author = {Essghaier, B and Mallat, N and Khwaldia, K and Mottola, F and Rocco, L and Hannachi, H}, title = {Production and Characterization of New Biosurfactants/Bioemulsifiers from Pantoea alhagi and Their Antioxidant, Antimicrobial and Anti-Biofilm Potentiality Evaluations.}, journal = {Molecules (Basel, Switzerland)}, volume = {28}, number = {4}, pages = {}, doi = {10.3390/molecules28041912}, pmid = {36838900}, issn = {1420-3049}, abstract = {The present work aimed to develop rapid approach monitoring using a simple selective method based on a positive hemolysis test, oil spreading activity and emulsification index determinations. It is the first to describe production of biosurfactants (BS) by the endophytic Pantoea alhagi species. Results indicated that the new BS evidenced an E24 emulsification index of 82%. Fourier-transform infrared (FTIR) results mentioned that the described BS belong to the glycolipid family. Fatty acid profiles showed the predominance of methyl 2-hyroxydodecanoate in the cell membrane (67.00%) and methyl 14-methylhexadecanoate (12.05%). The major fatty acid in the BS was oleic acid (76.26%), followed by methyl 12-methyltetradecanoate (10.93%). Markedly, the BS produced by the Pantoea alhagi species exhibited antimicrobial and anti-biofilm activities against tested human pathogens. With superior antibacterial activity against Escherchia coli and Staphylococcus aureus, a high antifungal effect was given against Fusarium sp. with a diameter of zone of inhibition of 29.5 mm, 36 mm and 31 mm, obtained by BS dissolved in methanol extract. The DPPH assay indicated that the BS (2 mg/mL) showed a higher antioxidant activity (78.07 inhibition percentage). The new BS exhibited specific characteristics, encouraging their use in various industrial applications.}, }
@article {pmid36838823, year = {2023}, author = {Nile, SH and Thombre, D and Shelar, A and Gosavi, K and Sangshetti, J and Zhang, W and Sieniawska, E and Patil, R and Kai, G}, title = {Antifungal Properties of Biogenic Selenium Nanoparticles Functionalized with Nystatin for the Inhibition of Candida albicans Biofilm Formation.}, journal = {Molecules (Basel, Switzerland)}, volume = {28}, number = {4}, pages = {}, doi = {10.3390/molecules28041836}, pmid = {36838823}, issn = {1420-3049}, abstract = {In the present study, biogenic selenium nanoparticles (SeNPs) have been prepared using Paenibacillus terreus and functionalized with nystatin (SeNP@PVP_Nystatin nanoconjugates) for inhibiting growth, morphogenesis, and a biofilm in Candida albicans. Ultraviolet-visible spectroscopy analysis has shown a characteristic absorption at 289, 303, and 318 nm, and X-ray diffraction analysis has shown characteristic peaks at different 2θ values for SeNPs. Electron microscopy analysis has shown that biogenic SeNPs are spherical in shape with a size in the range of 220-240 nm. Fourier transform infrared spectroscopy has confirmed the functionalization of nystatin on SeNPs (formation of SeNP@PVP_Nystatin nanoconjugates), and the zeta potential has confirmed the negative charge on the nanoconjugates. Biogenic SeNPs are inactive; however, nanoconjugates have shown antifungal activities on C. albicans (inhibited growth, morphogenesis, and a biofilm). The molecular mechanism for the action of nanoconjugates via a real-time polymerase chain reaction has shown that genes involved in the RAS/cAMP/PKA signaling pathway play an important role in antifungal activity. In cytotoxic studies, nanoconjugates have inhibited only 12% growth of the human embryonic kidney cell line 293 cells, indicating that the nanocomposites are not cytotoxic. Thus, the biogenic SeNPs produced by P. terreus can be used as innovative and effective drug carriers to increase the antifungal activity of nystatin.}, }
@article {pmid36838422, year = {2023}, author = {Morris, D and Flores, M and Harris, L and Gammon, J and Nigam, Y}, title = {Larval Therapy and Larval Excretions/Secretions: A Potential Treatment for Biofilm in Chronic Wounds? A Systematic Review.}, journal = {Microorganisms}, volume = {11}, number = {2}, pages = {}, doi = {10.3390/microorganisms11020457}, pmid = {36838422}, issn = {2076-2607}, abstract = {Chronic wounds present a global healthcare challenge and are increasing in prevalence, with bacterial biofilms being the primary roadblock to healing in most cases. A systematic review of the to-date knowledge on larval therapy's interaction with chronic-wound biofilm is presented here. The findings detail how larval therapy-the controlled application of necrophagous blowfly larvae-acts on biofilms produced by chronic-wound-relevant bacteria through their principle pharmacological mode of action: the secretion and excretion of biologically active substances into the wound bed. A total of 12 inclusion-criteria-meeting publications were identified following the application of a PRISMA-guided methodology for a systematic review. The findings of these publications were qualitatively analyzed to provide a summary of the prevailing understanding of larval therapy's effects on bacterial biofilm. A further review assessed the quality of the existing evidence to identify knowledge gaps and suggest ways these may be bridged. In summary, larval therapy has a seemingly unarguable ability to inhibit and degrade bacterial biofilms associated with impaired wound healing. However, further research is needed to clarify and standardize the methodological approach in this area of investigation. Such research may lead to the clinical application of larval therapy or derivative treatments for the management of chronic-wound biofilms and improve patient healing outcomes at a time when alternative therapies are desperately needed.}, }
@article {pmid36838406, year = {2023}, author = {Di Bonaventura, G and Picciani, C and Lupetti, V and Pompilio, A}, title = {Comparative Proteomic Analysis of Protein Patterns of Stenotrophomonas maltophilia in Biofilm and Planktonic Lifestyles.}, journal = {Microorganisms}, volume = {11}, number = {2}, pages = {}, doi = {10.3390/microorganisms11020442}, pmid = {36838406}, issn = {2076-2607}, abstract = {Stenotrophomonas maltophilia is a clinically relevant bacterial pathogen, particularly in cystic fibrosis (CF) patients. Despite the well-known ability to form biofilms inherently resistant to antibiotics and host immunity, many aspects involved in S. maltophilia biofilm formation are yet to be elucidated. In the present study, a proteomic approach was used to elucidate the differential protein expression patterns observed during the planktonic-to-biofilm transition of S. maltophilia Sm126, a strong biofilm producer causing chronic infection in a CF patient, to identify determinants potentially associated with S. maltophilia biofilm formation. In all, 57 proteins were differentially (3-fold; p < 0.01) expressed in biofilm cells compared with planktonic counterparts: 38 were overexpressed, and 19 were down-expressed. It is worth noting that 34 proteins were exclusively found in biofilm, mainly associated with quorum sensing-mediated intercellular communication, augmented glycolysis, amino acid metabolism, biosynthesis of secondary metabolites, phosphate signaling, response to nutrient starvation, and general stress. Further work is warranted to evaluate if these proteins can be suitable targets for developing anti-biofilm strategies effective against S. maltophilia.}, }
@article {pmid36838220, year = {2023}, author = {Viksne, R and Racenis, K and Broks, R and Balode, AO and Kise, L and Kroica, J}, title = {In Vitro Assessment of Biofilm Production, Antibacterial Resistance of Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter spp. Obtained from Tonsillar Crypts of Healthy Adults.}, journal = {Microorganisms}, volume = {11}, number = {2}, pages = {}, doi = {10.3390/microorganisms11020258}, pmid = {36838220}, issn = {2076-2607}, abstract = {BACKGROUND AND OBJECTIVE: Tonsillar crypts can be considered a reservoir for a variety of bacterial species. Some bacterial species can be considered part of the normal oropharyngeal microbiota. The roles of other pathogens, for example, the so-called non-oral and respiratory pathogens Staphylococcus aureus, Klebsiella, Pseudomonas, and Acinetobacter spp., which have strong virulence factors, biofilm production capacity, and the ability to initiate infectious diseases, are unclear. The purpose of this study was to detect the presence of S. aureus, K. pneumoniae, P. aeruginosa, and Acinetobacter spp. within the tonsillar crypts of healthy individuals, and to analyze the pathogens' biofilm production and antibacterial resistances.<br><br>RESULTS: Only common oropharyngeal microbiota were cultivated from 37 participant samples (40.7%). The most commonly isolated pathogenic bacterium was S. aureus, which was isolated in 41 (45%) participant samples. K. pneumoniae was isolated in seven (7.7%) samples, Acinetobacter spp. were isolated in five (5.5%) samples, and P. aeruginosa was isolated in two (2.2%) samples. Biofilm producers predominated among the pathogenic bacteria; 51 strains were biofilm producers, and among them, 31 strains were moderate or strong biofilm producers. The tested S. aureus, K. pneumoniae, P. aeruginosa, and Acinetobacter spp. strains were sensitive to commonly used antibiotics (amoxicillin-clavulanic acid, clindamycin, or ciprofloxacin). One of the isolated S. aureus strains was MRSA.<br><br>CONCLUSIONS: Biofilm is a commonly observed feature that seems to be a naturally existing form of pathogenic bacteria colonizing human tissue. S. aureus, K. pneumoniae, P. aeruginosa, and Acinetobacter spp. occasionally occur in the tonsillar crypts of healthy individuals, and, therefore, it is most likely that S. aureus, K. pneumoniae, P. aeruginosa, and Acinetobacter spp. in opportunistic tonsillar infections originate from the tonsillar crypt microbiota.}, }
@article {pmid36837628, year = {2023}, author = {Yang, H and Xu, Z and Xu, Z and Li, Y}, title = {Mini-Review of Biofilm Interactions with Surface Materials in Industrial Piping System.}, journal = {Membranes}, volume = {13}, number = {2}, pages = {}, doi = {10.3390/membranes13020125}, pmid = {36837628}, issn = {2077-0375}, abstract = {The growth of biofilm, which is caused by microorganism accumulation and growth on wetted surfaces, may damage industrial piping systems, increase maintenance and cleaning costs for the system sterilization, and even divulge the immune system into high risk. This article systematically analyzes the biofilm interactions with piping surface materials from the perspectives of physical convection, and biological and chemical adhesion. The thermodynamics of the flow, bacterial surface sensing, and bio-communication are the most critical factors for biofilm attachment. Furthermore, experimental analysis methods as well as biofilm control and removal approaches, are also included in this study. Finally, the resistance and growth of biofilm, as well as the practical and advanced methodology to control the biofilm and challenges associated with technology, are also discussed. Moreover, this paper may also offer a significant reference for the practice and strategic applications to address the biofilm resistance issues in industrial piping.}, }
@article {pmid36836905, year = {2023}, author = {Abdulhakeem, MA and Alreshidi, M and Bardakci, F and Hamadou, WS and De Feo, V and Noumi, E and Snoussi, M}, title = {Molecular Identification of Bacteria Isolated from Marketed Sparus aurata and Penaeus indicus Sea Products: Antibiotic Resistance Profiling and Evaluation of Biofilm Formation.}, journal = {Life (Basel, Switzerland)}, volume = {13}, number = {2}, pages = {}, doi = {10.3390/life13020548}, pmid = {36836905}, issn = {2075-1729}, abstract = {BACKGROUND: Marketed fish and shellfish are a source of multidrug-resistant and biofilm-forming foodborne pathogenic microorganisms.<br><br>METHODS: Bacteria isolated from Sparus aurata and Penaeus indicus collected from a local market in Hail region (Saudi Arabia) were isolated on selective and chromogenic media and identified by using 16S RNA sequencing technique. The exoenzyme production and the antibiotic susceptibility patterns of all identified bacteria were also tested. All identified bacteria were tested for their ability to form biofilm by using both qualitative and quantitative assays.<br><br>RESULTS: Using 16S RNA sequencing method, eight genera were identified dominated by Vibrio (42.85%), Aeromonas (23.80%), and Photobacterium (9.52%). The dominant species were V. natrigens (23.8%) and A. veronii (23.80%). All the identified strains were able to produce several exoenzymes (amylases, gelatinase, haemolysins, lecithinase, DNase, lipase, and caseinase). All tested bacteria were multidrug-resistant with a high value of the multiple antibiotic index (MARI). The antibiotic resistance index (ARI) was about 0.542 for Vibrio spp. and 0.553 for Aeromonas spp. On Congo red agar, six morphotypes were obtained, and 33.33% were slime-positive bacteria. Almost all tested microorganisms were able to form a biofilm on glass tube. Using the crystal violet technique, the tested bacteria were able to form a biofilm on glass, plastic, and polystyrene abiotic surfaces with different magnitude.<br><br>CONCLUSIONS: Our findings suggest that marketed S. aurata and P. indicus harbor various bacteria with human interest that are able to produce several related-virulence factors.}, }
@article {pmid36836852, year = {2023}, author = {Gajewska, J and Chajęcka-Wierzchowska, W and Byczkowska-Rostkowska, Z and Saki, M}, title = {Biofilm Formation Capacity and Presence of Virulence Determinants among Enterococcus Species from Milk and Raw Milk Cheeses.}, journal = {Life (Basel, Switzerland)}, volume = {13}, number = {2}, pages = {}, doi = {10.3390/life13020495}, pmid = {36836852}, issn = {2075-1729}, abstract = {Bacterial biofilm is one of the major hazards facing the food industry. Biofilm-forming ability is one of the most important virulence properties of enterococci. The genus Enterococcus includes pathogenic, spoilage, and pro-technological bacteria. The presence of enterococci in milk and dairy products is usually associated with inadequate hygiene practices. The study examined the isolates' capacity for biofilm formation and identification of the genetic determinants of its formation among 85 Enterococcus strains isolated from raw milk (n = 49) and soft-ripened cheeses made from unpasteurized milk (n = 36). E. faecalis and E. faecium were the dominant species. The obtained results showed that 41.4% isolates from milk and 50.0% isolates from cheeses were able to form biofilm. All of the isolates analyzed had at least one of the studied genes. As regards the isolates from raw milk, the most prevalent gene was the gelE (85.6%), followed by the asa1 (66.7%). None of the isolates from cheeses showed the presence of cylA and sprE. The most prevalent gene among the strains from this source was the epbC (94.4%), followed by the gelE (88.9%). In isolates from both sources, the presence of proteins from the Fsr group was noted the least frequently. Nevertheless, results showed that were no significant differences between the biofilm-producing Enterococcus spp. and non-biofilm-producing isolates in term of occurrences of tested virulence genes. The ability to produce a biofilm by enterococci isolated from raw milk or ready-to-eat products emphasizes the need for continuous monitoring of the mechanisms of microbial adhesion.}, }
@article {pmid36836656, year = {2023}, author = {Dhaouadi, S and Romdhani, A and Bouglita, W and Chedli, S and Chaari, S and Soufi, L and Cherif, A and Mnif, W and Abbassi, MS and Elandoulsi, RB}, title = {High Biofilm-Forming Ability and Clonal Dissemination among Colistin-Resistant Escherichia coli Isolates Recovered from Cows with Mastitis, Diarrheic Calves, and Chickens with Colibacillosis in Tunisia.}, journal = {Life (Basel, Switzerland)}, volume = {13}, number = {2}, pages = {}, doi = {10.3390/life13020299}, pmid = {36836656}, issn = {2075-1729}, abstract = {BACKGROUND: Escherichia coli (E. coli) is one of the main etiological agents responsible for bovine mastitis (BM), neonatal calf diarrhea (NCD), and avian colibacillosis (AC). This study aimed to assess resistance and virulence genes content, biofilm-forming ability, phylogenetic groups, and genetic relatedness in E. coli isolates recovered from clinical cases of BM, NCD, and AC.<br><br>MATERIALS/METHODS: A total of 120 samples including samples of milk (n = 70) and feces (n = 50) from cows with BM and calves with NCD, respectively, were collected from different farms in Northern Tunisia. Bacterial isolation and identification were performed. Then, E. coli isolates were examined by disk diffusion and broth microdilution method for their antimicrobial susceptibility and biofilm-forming ability. PCR was used to detect antimicrobial resistance genes (ARGs), virulence genes (VGs), phylogenetic groups, and Enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) for their clonal relationship.<br><br>RESULTS: Among the 120 samples, 67 E. coli isolates (25 from BM, 22 from AC, and 20 from NCD) were collected. Overall, 83.6% of isolates were multidrug resistant. Thirty-six (53.73%) isolates were phenotypically colistin-resistant (CREC), 28.3% (19/67) were ESBL producers (ESBL-EC), and forty-nine (73.1%) formed biofilm. The blaTEM gene was found in 73.7% (14/19) of isolates from the three diseases, whilst the blaCTXM-g-1 gene was detected in 47.3% (9/19) of isolates, all from AC. The most common VG was the fimA gene (26/36, 72.2%), followed by aer (12/36, 33.3%), cnf1 (6/36, 16.6%), papC (4/36, 11.1%), and stx1 and stx2 genes (2/36; 5.5% for each). Phylogenetic analysis showed that isolates belonged to three groups: A (20/36; 55.5%), B2 (7/36; 19.4%), and D (6/36; 16.6%). Molecular typing by ERIC-PCR showed high genetic diversity of CREC and ESBL E. coli isolates from the three animal diseases and gave evidence of their clonal dissemination within farms in Tunisia.<br><br>CONCLUSION: The present study sheds new light on the biofilm-forming ability and clonality within CREC and ESBL-EC isolated from three different animal diseases in Tunisian farm animals.}, }
@article {pmid36835662, year = {2023}, author = {Sánchez-Lozano, I and Muñoz-Cruz, LC and Hellio, C and Band-Schmidt, CJ and Cruz-Narváez, Y and Becerra-Martínez, E and Hernández-Guerrero, CJ}, title = {Metabolomic Insights of Biosurfactant Activity from Bacillus niabensis against Planktonic Cells and Biofilm of Pseudomonas stutzeri Involved in Marine Biofouling.}, journal = {International journal of molecular sciences}, volume = {24}, number = {4}, pages = {}, doi = {10.3390/ijms24044249}, pmid = {36835662}, issn = {1422-0067}, abstract = {In marine environments, biofilm can cause negative impacts, including the biofouling process. In the search for new non-toxic formulations that inhibit biofilm, biosurfactants (BS) produced by the genus Bacillus have demonstrated considerable potential. To elucidate the changes that BS from B. niabensis promote in growth inhibition and biofilm formation, this research performed a nuclear magnetic resonance (NMR) metabolomic profile analysis to compare the metabolic differences between planktonic cells and biofilms of Pseudomonas stutzeri, a pioneer fouling bacteria. The multivariate analysis showed a clear separation between groups with a higher concentration of metabolites in the biofilm than in planktonic cells of P. stutzeri. When planktonic and biofilm stages were treated with BS, some differences were found among them. In planktonic cells, the addition of BS had a minor effect on growth inhibition, but at a metabolic level, NADP+, trehalose, acetone, glucose, and betaine were up-regulated in response to osmotic stress. When the biofilm was treated with the BS, a clear inhibition was observed and metabolites such as glucose, acetic acid, histidine, lactic acid, phenylalanine, uracil, and NADP+ were also up-regulated, while trehalose and histamine were down-regulated in response to the antibacterial effect of the BS.}, }
@article {pmid36835442, year = {2023}, author = {Balducci, E and Papi, F and Capialbi, DE and Del Bino, L}, title = {Polysaccharides' Structures and Functions in Biofilm Architecture of Antimicrobial-Resistant (AMR) Pathogens.}, journal = {International journal of molecular sciences}, volume = {24}, number = {4}, pages = {}, doi = {10.3390/ijms24044030}, pmid = {36835442}, issn = {1422-0067}, abstract = {Bacteria and fungi have developed resistance to the existing therapies such as antibiotics and antifungal drugs, and multiple mechanisms are mediating this resistance. Among these, the formation of an extracellular matrix embedding different bacterial cells, called biofilm, is an effective strategy through which bacterial and fungal cells are establishing a relationship in a unique environment. The biofilm provides them the possibility to transfer genes conferring resistance, to prevent them from desiccation and to impede the penetration of antibiotics or antifungal drugs. Biofilms are formed of several constituents including extracellular DNA, proteins and polysaccharides. Depending on the bacteria, different polysaccharides form the biofilm matrix in different microorganisms, some of them involved in the first stage of cells' attachment to surfaces and to each other, and some responsible for giving the biofilm structure resistance and stability. In this review, we describe the structure and the role of different polysaccharides in bacterial and fungal biofilms, we revise the analytical methods to characterize them quantitatively and qualitatively and finally we provide an overview of potential new antimicrobial therapies able to inhibit biofilm formation by targeting exopolysaccharides.}, }
@article {pmid36834746, year = {2023}, author = {Ji, MK and Lee, SK and Kim, HS and Oh, GJ and Cho, H and Lim, HP}, title = {Assessment of Inhibition of Biofilm Formation on Non-Thermal Plasma-Treated TiO2 Nanotubes.}, journal = {International journal of molecular sciences}, volume = {24}, number = {4}, pages = {}, doi = {10.3390/ijms24043335}, pmid = {36834746}, issn = {1422-0067}, abstract = {Peri-implantitis is an inflammatory disease similar to periodontitis, caused by biofilms formed on the surface of dental implants. This inflammation can spread to bone tissues and result in bone loss. Therefore, it is essential to inhibit the formation of biofilms on the surface of dental implants. Thus, this study examined the inhibition of biofilm formation by treating TiO2 nanotubes with heat and plasma. Commercially pure titanium specimens were anodized to form TiO2 nanotubes. Heat treatment was performed at 400 and 600 °C, and atmospheric pressure plasma was applied using a plasma generator (PGS-200, Expantech, Suwon, Republic of Korea). Contact angles, surface roughness, surface structure, crystal structure, and chemical compositions were measured to analyze the surface properties of the specimens. The inhibition of biofilm formation was assessed using two methods. The results of this study showed that the heat treatment of TiO2 nanotubes at 400 °C inhibited the adhesion of Streptococcus mutans (S. mutans), associated with initial biofilm formation, and that heat treatment of TiO2 nanotubes at 600 °C inhibited the adhesion of Porphyromonas gingivalis (P. gingivalis), which causes peri-implantitis. Applying plasma to the TiO2 nanotubes heat-treated at 600 °C inhibited the adhesion of S. mutans and P. gingivalis.}, }
@article {pmid36834725, year = {2023}, author = {Karczewska, M and Strzelecki, P and Bogucka, K and Potrykus, K and Szalewska-Pałasz, A and Nowicki, D}, title = {Increased Levels of (p)ppGpp Correlate with Virulence and Biofilm Formation, but Not with Growth, in Strains of Uropathogenic Escherichia coli.}, journal = {International journal of molecular sciences}, volume = {24}, number = {4}, pages = {}, doi = {10.3390/ijms24043315}, pmid = {36834725}, issn = {1422-0067}, abstract = {Urinary tract infections are one of the most frequent bacterial diseases worldwide. UPECs are the most prominent group of bacterial strains among pathogens responsible for prompting such infections. As a group, these extra-intestinal infection-causing bacteria have developed specific features that allow them to sustain and develop in their inhabited niche of the urinary tract. In this study, we examined 118 UPEC isolates to determine their genetic background and antibiotic resistance. Moreover, we investigated correlations of these characteristics with the ability to form biofilm and to induce a general stress response. We showed that this strain collection expressed unique UPEC attributes, with the highest representation of FimH, SitA, Aer, and Sfa factors (100%, 92.5%, 75%, and 70%, respectively). According to CRA (Congo red agar) analysis, the strains particularly predisposed to biofilm formation represented 32.5% of the isolates. Those biofilm forming strains presented a significant ability to accumulate multi-resistance traits. Most notably, these strains presented a puzzling metabolic phenotype-they showed elevated basal levels of (p)ppGpp in the planktonic phase and simultaneously exhibited a shorter generation time when compared to non-biofilm-forming strains. Moreover, our virulence analysis showed these phenotypes to be crucial for the development of severe infections in the Galleria mellonella model.}, }
@article {pmid36834695, year = {2023}, author = {Ismail, S and Gaglione, R and Masi, M and Padhi, S and Rai, AK and Omar, G and Cimmino, A and Arciello, A}, title = {Ephedra foeminea as a Novel Source of Antimicrobial and Anti-Biofilm Compounds to Fight Multidrug Resistance Phenotype.}, journal = {International journal of molecular sciences}, volume = {24}, number = {4}, pages = {}, doi = {10.3390/ijms24043284}, pmid = {36834695}, issn = {1422-0067}, abstract = {Plants are considered a wealthy resource of novel natural drugs effective in the treatment of multidrug-resistant infections. Here, a bioguided purification of Ephedra foeminea extracts was performed to identify bioactive compounds. The determination of antimicrobial properties was achieved by broth microdilution assays to evaluate minimal inhibitory concentration (MIC) values and by crystal violet staining and confocal laser scanning microscopy analyses (CLSM) to investigate the antibiofilm capacity of the isolated compounds. Assays were performed on a panel of three gram-positive and three gram-negative bacterial strains. Six compounds were isolated from E. foeminea extracts for the first time. They were identified by nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS) analyses as the well-known monoterpenoid phenols carvacrol and thymol and as four acylated kaempferol glycosides. Among them, the compound kaempferol-3-O-α-L-(2″,4″-di-E-p-coumaroyl)-rhamnopyranoside was found to be endowed with strong antibacterial properties and significant antibiofilm activity against S. aureus bacterial strains. Moreover, molecular docking studies on this compound suggested that the antibacterial activity of the tested ligand against S. aureus strains might be correlated to the inhibition of Sortase A and/or of tyrosyl tRNA synthase. Collectively, the results achieved open interesting perspectives to kaempferol-3-O-α-L-(2″,4″-di-E-p-coumaroyl)-rhamnopyranoside applicability in different fields, such as biomedical applications and biotechnological purposes such as food preservation and active packaging.}, }
@article {pmid36831057, year = {2023}, author = {Avraham, M and Steinberg, D and Barak, T and Shalish, M and Feldman, M and Sionov, RV}, title = {Improved Anti-Biofilm Effect against the Oral Cariogenic Streptococcus mutans by Combined Triclosan/CBD Treatment.}, journal = {Biomedicines}, volume = {11}, number = {2}, pages = {}, doi = {10.3390/biomedicines11020521}, pmid = {36831057}, issn = {2227-9059}, abstract = {Streptococcus mutans is a Gram-positive bacterium highly associated with dental caries, and it has a strong biofilm-forming ability, especially in a sugar-rich environment. Many strategies have been undertaken to prevent dental caries by targeting these bacteria. Recently, we observed that a sustained-release varnish containing triclosan and cannabidiol (CBD) was more efficient than each compound alone in preventing biofilm formation by the fungus Candida albicans, which is frequently involved in oral infections together with S. mutans. It was therefore inquiring to study the effect of this drug combination on S. mutans. We observed that the combined treatment of triclosan and CBD had stronger anti-bacterial and anti-biofilm activity than each compound alone, thus enabling the use of lower concentrations of each drug to achieve the desired effect. The combined drug treatment led to an increase in the SYTO 9[low], propidium iodide (PI)[high] bacterial population as analyzed by flow cytometry, indicative for bacteria with disrupted membrane. Both triclosan and CBD induced membrane hyperpolarization, although there was no additive effect on this parameter. HR-SEM images of CBD-treated bacteria show the appearance of elongated and swollen bacteria with several irregular septa structures, and upon combined treatment with triclosan, the bacteria took on a swollen ellipse and sometimes oval morphology. Increased biofilm formation was observed at sub-MIC concentrations of each compound alone, while combining the drugs at these sub-MIC concentrations, the biofilm formation was prevented. The inhibition of biofilm formation was confirmed by CV biomass staining, MTT metabolic activity, HR-SEM and live/dead together with exopolysaccharide (EPS) staining visualized by spinning disk confocal microscopy. Importantly, the concentrations required for the anti-bacterial and anti-biofilm activities toward S. mutans were non-toxic to the normal Vero epithelial cells. In conclusion, the data obtained in this study propose a beneficial role of combined triclosan/CBD treatment for potential protection against dental caries.}, }
@article {pmid36830328, year = {2023}, author = {Abd El-Rahman, OA and Rasslan, F and Hassan, SS and Ashour, HM and Wasfi, R}, title = {The RND Efflux Pump Gene Expression in the Biofilm Formation of Acinetobacter baumannii.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {2}, pages = {}, doi = {10.3390/antibiotics12020419}, pmid = {36830328}, issn = {2079-6382}, abstract = {Multidrug resistant (MDR) Acinetobacter baumannii is a critical opportunistic pathogen in healthcare-associated infections (HAI). This is attributed to several factors, including its ability to develop biofilms that can enhance antimicrobial resistance (AMR) in addition to creating an environment for horizontal transfer of antibiotic resistance genes. The role of the efflux pump in biofilm formation is important for studies on alternative treatments for biofilms. One of the significant efflux pump families is the RND efflux pump family, which is common in Gram negative bacteria. The aim is to study the role of the RND efflux pump in biofilm formation by A. baumannii. The biofilm formation potential of thirty-four MDR A. baumannii isolates was evaluated by crystal violet assays. The effect of efflux pump inhibition and activation was studied using the efflux pump inhibitor carbonyl cyanide 3-chlorophenylhydrazone (CCCP) and the RND efflux pump substrate levofloxacin (at sub-MIC), respectively. The isolates were genotypically grouped by enterobacterial repetitive intergenic consensus (ERIC) typing and the expression of adeABC, adeFGH, and adeIJK efflux pump genes was measured by qPCR. Overall, 88.2% (30/34) of isolates were biofilm producers (the phenotype was variable including strong and weak producers). Efflux pump inhibition by CCCP reduced the biofilm formation significantly (p < 0.05) in 17.6% (6/34) of some isolates, whereas sub-MICs of the substrate levofloxacin increased biofilm formation in 20.5% (7/34) of other isolates. Overexpression of the three RND efflux pump genes was detected in five out of eleven selected isolates for qPCR with remarkable overexpression in the adeJ gene. No correlation was detected between the biofilm phenotype pattern and the RND efflux pump gene expression in biofilm cells relative to planktonic cells. In conclusion, the role of the RND efflux pumps AdeABC, AdeFGH, and AdeIJK in biofilm formation does not appear to be pivotal and the expression differs according to the genetic background of each strain. Thus, these pumps may not be a promising target for biofilm inhibition.}, }
@article {pmid36830299, year = {2023}, author = {Ridyard, KE and Elsawy, M and Mattrasingh, D and Klein, D and Strehmel, J and Beaulieu, C and Wong, A and Overhage, J}, title = {Synergy between Human Peptide LL-37 and Polymyxin B against Planktonic and Biofilm Cells of Escherichia coli and Pseudomonas aeruginosa.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {2}, pages = {}, doi = {10.3390/antibiotics12020389}, pmid = {36830299}, issn = {2079-6382}, abstract = {The rise in antimicrobial resistant bacteria is limiting the number of effective treatments for bacterial infections. Escherichia coli and Pseudomonas aeruginosa are two of the pathogens with the highest prevalence of resistance, and with the greatest need for new antimicrobial agents. Combinations of antimicrobial peptides (AMPs) and antibiotics that display synergistic effects have been shown to be an effective strategy in the development of novel therapeutic agents. In this study, we investigated the synergy between the AMP LL-37 and various classes of antibiotics against E. coli and P. aeruginosa strains. Of the six antibiotics tested (ampicillin, tetracycline, ciprofloxacin, gentamicin, aztreonam, and polymyxin B (PMB)), LL-37 displayed the strongest synergy against E. coli MG1655 and P. aeruginosa PAO1 laboratory strains when combined with PMB. Given the strong synergy, the PMB + LL-37 combination was chosen for further examination where it demonstrated synergy against multidrug-resistant and clinical E. coli isolates. Synergy of PMB + LL-37 towards clinical isolates of P. aeruginosa varied and showed synergistic, additive, or indifferent effects. The PMB + LL-37 combination treatment showed significant prevention of biofilm formation as well as eradication of pre-grown E. coli and P. aeruginosa biofilms. Using the Galleria mellonella wax worm model, we showed that the PMB + LL-37 combination treatment retained its antibacterial capacities in vivo. Flow analyses were performed to characterize the mode of action. The results of the present study provide proof of principle for the synergistic response between LL-37 and PMB and give novel insights into a promising new antimicrobial combination against gram-negative planktonic and biofilm cells.}, }
@article {pmid36830295, year = {2023}, author = {Ersanli, C and Tzora, A and Skoufos, I and Fotou, K and Maloupa, E and Grigoriadou, K and Voidarou, CC and Zeugolis, DI}, title = {The Assessment of Antimicrobial and Anti-Biofilm Activity of Essential Oils against Staphylococcus aureus Strains.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {2}, pages = {}, doi = {10.3390/antibiotics12020384}, pmid = {36830295}, issn = {2079-6382}, abstract = {The increase in antimicrobial resistance and tolerance over the years has become a serious public health problem, leading to the inevitable development of alternative antimicrobial agents as substitutes for industrial pharmaceutical antibiotics targeting humans and animals under the concept of one health. Essential oils (EOs) extracted from aromatic and pharmaceutical plants incorporate several bioactive compounds (phytochemicals) that positively affect human and animal health. Herein, this work aimed to examine a standardized chemical composition and screen the antimicrobial and anti-biofilm activity of Thymus sibthorpii, Origanum vulgare, Salvia fruticosa, and Crithmum maritimum EOs against three different Staphylococcus aureus strains by gold-standard disc diffusion, broth microdilution, and microtiter plate biofilm assays. Therefore, the evaluation of the above-mentioned EOs were considered as substitutes for antibiotics to combat the ever-mounting antimicrobial resistance problem. The observed bacterial growth inhibition varied significantly depending on the type and concentration of the antimicrobials. Thymus sibthorpii was determined as the strongest antimicrobial, with 0.091 mg/mL minimum inhibitory concentration (MIC) and a 14-33 mm diameter inhibition zone at 5% (v/v) concentration. All tested EOs indicated almost 95% inhibition of biofilm formation at their half MIC, while gentamicin sulfate did not show sufficient anti-biofilm activity. None of the methicillin-resistant strains showed resistance to the EOs compared to methicillin-sensitive strains. Thymus sibthorpii and Origanum vulgare could be potential alternatives as antimicrobial agents to overcome the problem of microbial resistance. The tested EOs might be incorporated into antimicrobial products as safe and potent antimicrobial and anti-biofilm agents.}, }
@article {pmid36830264, year = {2023}, author = {Baltogianni, M and Giapros, V and Kosmeri, C}, title = {Antibiotic Resistance and Biofilm Infections in the NICUs and Methods to Combat It.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {2}, pages = {}, doi = {10.3390/antibiotics12020352}, pmid = {36830264}, issn = {2079-6382}, abstract = {Neonatal sepsis is an important cause of neonatal morbidity and mortality. A significant proportion of bacteria causing neonatal sepsis is resistant to multiple antibiotics, not only to the usual empirical first-line regimens, but also to second- and third-line antibiotics in many neonatal intensive care units (NICUs). NICUs have unique antimicrobial stewardship goals. Apart from antimicrobial resistance, NICUs have to deal with another problem, namely biofilm infections, since neonates often have central and peripheral lines, tracheal tubes and other foreign bodies for a prolonged duration. The aim of this review is to describe traditional and novel ways to fight antibiotic-resistant bacteria and biofilm infections in NICUs. The topics discussed will include prevention and control of the spread of infection in NICUs, as well as the wise use of antimicrobial therapy and ways to fight biofilm infections.}, }
@article {pmid36830260, year = {2023}, author = {Kim, YM and Son, H and Park, SC and Lee, JK and Jang, MK and Lee, JR}, title = {Anti-Biofilm Effects of Rationally Designed Peptides against Planktonic Cells and Pre-Formed Biofilm of Pseudomonas aeruginosa.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {2}, pages = {}, doi = {10.3390/antibiotics12020349}, pmid = {36830260}, issn = {2079-6382}, abstract = {Biofilms are resistant to antibiotics and are a major source of persistent and recurring infections by clinically important pathogens. Drugs used for biofilm-associated infections are limited because biofilm-embedded or biofilm-matrix bacteria are difficult to kill or eradiate. Therefore, many researchers are developing new and effective antibiofilm agents. Among them, antimicrobial peptides have an attractive interest in the development of antibiofilm agents. The present study evaluated the effects of 10 synthetic peptides on growth inhibition, inhibition of biofilm formation, and biofilm elimination in drug-resistant Pseudomonas aeruginosa. The planktonic cell growth and biofilm formation were dose-dependently inhibited by most of the peptides. WIK-14 eliminated preformed biofilm masses by removing carbohydrates, extracellular nucleic acids, proteins, and lipids constituting extracellular polymeric substances. The results demonstrated that WIK-14 and WIKE-14 peptides might provide novel therapeutic drugs to overcome multidrug resistance in biofilm-associated infections.}, }
@article {pmid36830240, year = {2023}, author = {Ribeiro, SM and Bueno, PCP and Cavalheiro, AJ and Klein, MI}, title = {Effect of Extracts, Fractions, and Isolated Molecules of Casearia sylvestris to Control Streptococcus mutans Cariogenic Biofilm.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {2}, pages = {}, doi = {10.3390/antibiotics12020329}, pmid = {36830240}, issn = {2079-6382}, abstract = {The effects of extracts, fractions, and molecules of Casearia sylvestris to control the cariogenic biofilm of Streptococcus mutans were evaluated. First, the antimicrobial and antibiofilm (initial and pre-formed biofilms) in prolonged exposure (24 h) models were investigated. Second, formulations (with and without fluoride) were assessed for topical effects (brief exposure) on biofilms. Third, selected treatments were evaluated via bacterium growth inhibition curves associated with gene expression and scanning electron microscopy. In initial biofilms, the ethyl acetate (AcOEt) and ethanolic (EtOH) fractions from Brasília (BRA/DF; 250 µg/mL) and Presidente Venceslau/SP (Water/EtOH 60:40 and Water/EtOH 40:60; 500 µg/mL) reduced ≥6-logs vs. vehicle. Only the molecule Caseargrewiin F (CsF; 125 µg/mL) reduced the viable cell count of pre-formed biofilms (5 logs vs. vehicle). For topical effects, no formulation affected biofilm components. For the growth inhibition assay, CsF yielded a constant recovery of surviving cells (≅3.5 logs) until 24 h (i.e., bacteriostatic), and AcOEt_BRA/DF caused progressive cell death, without cells at 24 h (i.e., bactericidal). CsF and AcOEt_BRA/DF damaged S. mutans cells and influenced the expression of virulence genes. Thus, an effect against biofilms occurred after prolonged exposure due to the bacteriostatic and/or bactericidal capacity of a fraction and a molecule from C. sylvestris.}, }
@article {pmid36830229, year = {2023}, author = {Senneville, E and Gachet, B and Blondiaux, N and Robineau, O}, title = {Do Anti-Biofilm Antibiotics Have a Place in the Treatment of Diabetic Foot Osteomyelitis?.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {2}, pages = {}, doi = {10.3390/antibiotics12020317}, pmid = {36830229}, issn = {2079-6382}, abstract = {The choice of antibiotic regimens for use in patients presenting with diabetic foot osteomyelitis and their duration differs according to the situation. Antibiotics play a more important role in the medical option where no infected bone has been resected, while their role is reduced but not negligible in the case of surgical options. Some studies have reported the presence of biofilm structures in bone samples taken from patients with diabetic foot osteomyelitis, which raises the question of the place of anti-biofilm antibiotic regimens in this setting. During the last two decades, clinical studies have suggested a potential benefit for anti-biofilm antibiotics, mainly rifampicin against staphylococci and fluoroquinolones against gram-negative bacilli. However, no data from randomized controlled studies have been reported so far. The present work provides a summary of the available data on the question of the place of anti-biofilm antibiotics for the treatment of diabetic foot osteomyelitis, but also the potential limitations of such treatments.}, }
@article {pmid36830210, year = {2023}, author = {Shamim, A and Ali, A and Iqbal, Z and Mirza, MA and Aqil, M and Kawish, SM and Siddiqui, A and Kumar, V and Naseef, PP and Alshadidi, AAF and Saheer Kuruniyan, M}, title = {Natural Medicine a Promising Candidate in Combating Microbial Biofilm.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {2}, pages = {}, doi = {10.3390/antibiotics12020299}, pmid = {36830210}, issn = {2079-6382}, abstract = {Studies on biofilm-related infections are gaining prominence owing to their involvement in most clinical infections and seriously threatening global public health. A biofilm is a natural form of bacterial growth ubiquitous in ecological niches, considered to be a generic survival mechanism adopted by both pathogenic and non-pathogenic microorganisms and entailing heterogeneous cell development within the matrix. In the ecological niche, quorum sensing is a communication channel that is crucial to developing biofilms. Biofilm formation leads to increased resistance to unfavourable ecological effects, comprising resistance to antibiotics and antimicrobial agents. Biofilms are frequently combated with modern conventional medicines such as antibiotics, but at present, they are considered inadequate for the treatment of multi-drug resistance; therefore, it is vital to discover some new antimicrobial agents that can prevent the production and growth of biofilm, in addition to minimizing the side effects of such therapies. In the search for some alternative and safe therapies, natural plant-derived phytomedicines are gaining popularity among the research community. Phytomedicines are natural agents derived from natural plants. These plant-derived agents may include flavonoids, terpenoids, lectins, alkaloids, polypeptides, polyacetylenes, phenolics, and essential oils. Since they are natural agents, they cause minimal side effects, so could be administered with dose flexibility. It is vital to discover some new antimicrobial agents that can control the production and growth of biofilms. This review summarizes and analyzes the efficacy characteristics and corresponding mechanisms of natural-product-based antibiofilm agents, i.e., phytochemicals, biosurfactants, antimicrobial peptides, and their sources, along with their mechanism, quorum sensing signalling pathways, disrupting extracellular matrix adhesion. The review also provides some other strategies to inhibit biofilm-related illness. The prepared list of newly discovered natural antibiofilm agents could help in devising novel strategies for biofilm-associated infections.}, }
@article {pmid36830203, year = {2023}, author = {Moshynets, OV and Baranovskyi, TP and Iungin, OS and Krikunov, AA and Potochilova, VV and Rudnieva, KL and Potters, G and Pokholenko, I}, title = {Therapeutic Potential of an Azithromycin-Colistin Combination against XDR K. pneumoniae in a 3D Collagen-Based In Vitro Wound Model of a Biofilm Infection.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {2}, pages = {}, doi = {10.3390/antibiotics12020293}, pmid = {36830203}, issn = {2079-6382}, abstract = {A therapeutic combination of azithromycin (AZM) and colistin methanesulfonate (CMS) was shown to be effective against both non-PDR and PDR Klebsiella pneumoniae biofilms in vitro. These anti-biofilm effects, however, may not correlate with effects observed in standard plate assays, nor will they representative of in vivo therapeutic action. After all, biofilm-associated infection processes are also impacted by the presence of wound bed components, such as host cells or wound fluids, which can all affect the antibiotic effectiveness. Therefore, an in vitro wound model of biofilm infection which partially mimics the complex microenvironment of infected wounds was developed to investigate the therapeutic potential of an AZM-CMS combination against XDR K. pneumoniae isolates. The model consists of a 3D collagen sponge-like scaffold seeded with HEK293 cells submerged in a fluid milieu mimicking the wound bed exudate. Media that were tested were all based on different strengths of Dulbecco's modified Eagles/high glucose medium supplemented with fetal bovine serum, and/or Bacto Proteose peptone. Use of this model confirmed AZM to be a highly effective antibiofilm component, when applied alone or in combination with CMS, whereas CMS alone had little antibacterial effectiveness or even stimulated biofilm development. The wound model proposed here proves therefore, to be an effective aid in the study of drug combinations under realistic conditions.}, }
@article {pmid36830150, year = {2023}, author = {Farha, AK and Sui, Z and Corke, H}, title = {Raspberry Ketone-Mediated Inhibition of Biofilm Formation in Salmonella enterica Typhimurium-An Assessment of the Mechanisms of Action.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {2}, pages = {}, doi = {10.3390/antibiotics12020239}, pmid = {36830150}, issn = {2079-6382}, abstract = {Salmonella enterica is an important foodborne pathogen that causes gastroenteritis and systemic infection in humans and livestock. Salmonella biofilms consist of two major components-amyloid curli and cellulose-which contribute to the prolonged persistence of Salmonella inside the host. Effective agents for inhibiting the formation of biofilms are urgently needed. We investigated the antibiofilm effect of Raspberry Ketone (RK) and its mechanism of action against Salmonella Typhimurium 14028 using the Congo red agar method, Calcofluor staining, crystal violet method, pellicle assay, and the TMT-labeled quantitative proteomic approach. RK suppressed the formation of different types of Salmonella biofilms, including pellicle formation, even at low concentrations (200 µg/mL). Furthermore, at higher concentrations (2 mg/mL), RK exhibited bacteriostatic effects. RK repressed cellulose deposition in Salmonella biofilm through an unknown mechanism. Swimming and swarming motility analyses demonstrated reduced motility in RK-treated S. typhimurium. Proteomics analysis revealed that pathways involved in amyloid curli production, bacterial invasion, flagellar motility, arginine biosynthesis, and carbohydrate metabolism, were targeted by RK to facilitate biofilm inhibition. Consistent with the proteomics data, the expressions of csgB and csgD genes were strongly down-regulated in RK-treated S. typhimurium. These findings clearly demonstrated the Salmonella biofilm inhibition capability of RK, justifying its further study for its efficacy assessment in clinical and industrial settings.}, }
@article {pmid36830146, year = {2023}, author = {Miłek, M and Ciszkowicz, E and Sidor, E and Hęclik, J and Lecka-Szlachta, K and Dżugan, M}, title = {The Antioxidant, Antibacterial and Anti-Biofilm Properties of Rapeseed Creamed Honey Enriched with Selected Plant Superfoods.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {2}, pages = {}, doi = {10.3390/antibiotics12020235}, pmid = {36830146}, issn = {2079-6382}, abstract = {The aim of the study is to evaluate the effect of the addition of selected fruits and herbs belonging to the "superfoods" category for the bioactivity of a rapeseed honey matrix. Flavored creamed honeys with nine types of various additives (2 and 4% of content) were prepared and analyzed for the content of total phenols, flavonoids, antioxidant (FRAP, DPPH and ABTS) and antibacterial activity against four strains of bacteria. Additionally, the impact of three months of storage on the antioxidant properties of the products obtained was examined. The significant dose-dependent increase in the content of bioactive ingredients and antioxidant capacity in spiced honeys, as compared to control honey, was observed. The highest enrichment was obtained for the addition of powdered sea buckthorn leaves and black raspberry fruits. Honey with the addition of sea buckthorn leaves inhibited the growth of P. aeruginosa, S. aureus and K. pneumonia, whereas honeys with black raspberry and blackcurrant fruits showed activity only on the latter two strains. Furthermore, what is more interesting, honey supplemented with sea buckthorn leaf and black raspberry fruits inhibited S. aureus biofilm formation at the sub-minimum inhibitory concentrations (sub-MICs), showing a dose-dependent anti-biofilm effect.}, }
@article {pmid36830100, year = {2023}, author = {Amábile-Cuevas, CF}, title = {Macrolides at Clinically-Relevant Concentrations May Induce Biofilm Formation in Macrolide-Resistant Staphylococcus aureus.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {2}, pages = {}, doi = {10.3390/antibiotics12020187}, pmid = {36830100}, issn = {2079-6382}, abstract = {Macrolides inhibit biofilm formation in several Gram-negative, intrinsically-resistant bacterial species. However, the effect of macrolides upon biofilm formation by susceptible Gram-positive bacteria has been much less explored as such concentrations also inhibit cell growth. To circumvent this problem, the effect of macrolides (erythromycin, clarithromycin and azithromycin) at 0.5-2 µg/mL, upon biofilm formation, was explored on macrolide-resistant Staphylococcus aureus isolates, using the crystal violet assay with 96-well plates. Early (4 h) biofilm formation by strains having constitutive target-modification resistance was consistently induced by all macrolides but not in azithromycin-treated cells in longer (8 and 12 h) incubation. In inducible-resistance isolates, early biofilm formation was enhanced by some macrolide treatments, compared to similar cell growth in the absence of antibiotics; but the typical decay of biofilms at longer incubation appeared prematurely in macrolide-treated cultures. Biofilm formation in an efflux-mediated resistant isolate was not affected by macrolides. These results indicate that macrolides induce the formation of biofilm by resistant S. aureus isolates, especially during the early stages. This suggests that the empirical use of macrolides against infections caused by resistant S. aureus strains could not only result in clinical failure but even in the enhancement of biofilms, making further treatment difficult.}, }
@article {pmid36828058, year = {2023}, author = {Yuan, S and Guo, S and Tan, Y and Li, M and Lu, Y and Xu, R and Tawfik, A and Zhou, Z and Chen, J and Liu, W and Meng, F}, title = {Deciphering community assembly and succession in sequencing batch moving bed biofilm reactor: Differentiation between attached and suspended communities.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {162448}, doi = {10.1016/j.scitotenv.2023.162448}, pmid = {36828058}, issn = {1879-1026}, abstract = {Elucidating community assembly and succession is crucial to understanding the ecosystem functioning. Herein, the ecological processes underpinning community assembly and succession were studied to uncover the respective ecological functions of attached biofilms and suspended biomass in a sequencing batch moving bed biofilm reactor. Compared with suspended biomass, attached biofilms presented higher relative abundances of Nitrospira (2.94 %) and Nitrosomonas (1.25 %), and contributed to 66.89 ± 11.37 % and 68.11 ± 12.72 % of nitrification and denitrification activities, respectively. The microbial source tracking result demonstrated that early formation of suspended biomass was dominated by the seeding effect of detached biofilms in the start-up period (days 0-30), while self-growth of previous suspended biomass was eventually outcompeted the seeding effect when the reactor stabilized (days 31-120). Null model and ecological network analysis further suggested distinctive ecological processes underpinning the differentiation between attached and suspended communities in the same reactor. Specifically, in the start-up period, positive interactions facilitated early formation of attached (73.84 %) and suspended communities (59.41 %), while homogenous selection (88.89 %) and homogenizing dispersal (65.71 %) governed assembly of attached and suspended communities, respectively. When the reactor stabilized, attached and suspended communities showed low composition turnover as reflected by dominant homogenizing dispersal, while they presented distinctive trends of interspecies interactions. This study sheds light on discrepant ecological processes governing community differentiation of attached biofilms and suspended biomass, which would provide ecological insights into the regulation of hybrid ecosystems.}, }
@article {pmid36826286, year = {2023}, author = {Pessanha, FS and Oliveira, BGRB and Oliveira, BC and Deutsch, G and Teixeira, FL and Bokehi, LC and Calomino, MA and Rodrigues de Castilho, S and Thiré, RMDSM and Teixeira, LA and Paula, GR}, title = {Effectiveness of Epidermal Growth Factor Loaded Carboxymethylcellulose (EGF-CMC) Hydrogel in Biofilm Formation in Wounds of Diabetic Patients: A Randomized Clinical Trial.}, journal = {Gels (Basel, Switzerland)}, volume = {9}, number = {2}, pages = {}, pmid = {36826286}, issn = {2310-2861}, abstract = {Diabetic patients frequently develop wounds, which can be colonized by bacteria, mainly Staphylococcus aureus and Pseudomonas aeruginosa, with the ability to form biofilms. This study aimed to evaluate the colonization and biofilm formation of Staphylococcus aureus and Pseudomonas aeruginosa in chronic wounds of diabetic patients treated with a bioactive dressing (EGF-CMC), which consisted of a 2% carboxymethylcellulose (CMC) hydrogel loaded with epidermal growth factor (EGF). This randomized clinical trial was conducted with 25 participants: 14 treated with EGF-CMC hydrogel and 11 treated with CMC hydrogel for 12 weeks. Participants with type 2 diabetes mellitus were selected. All had diabetic foot ulcers or chronic venous ulcers. Swab collections were performed on weeks 1, 6, and 12. The laboratory analyses included the identification of strains, microbial quantification, virulence gene investigation, and the evaluation of biofilm formation. In total, 13 S. aureus strains and 15 P. aeruginosa strains were isolated. There were no statistically significant differences regarding bacterial loads and virulence genes. However, EGF-CMC-hydrogel-treated wounds were colonized by strains with lower biofilm formation abilities. The probability of isolating biofilm-producing strains from CMC-hydrogel-treated wounds was 83% greater than the probability of isolating biofilm-producing strains from EGF-CMC-treated wounds.}, }
@article {pmid36825362, year = {2023}, author = {Park, EH and Park, R and Seo, J and Kim, W and Kim, HY and Shon, WJ}, title = {Efficacy of a novel remotely-generated ultrasonic root canal irrigation system for removing biofilm-mimicking hydrogel from a simulated isthmus model.}, journal = {International endodontic journal}, volume = {}, number = {}, pages = {}, doi = {10.1111/iej.13905}, pmid = {36825362}, issn = {1365-2591}, abstract = {AIM: To evaluate the efficacy of a novel ultrasonic irrigation device, remotely-generated irrigation with a non-invasive sound field enhancement (RINSE) system, in removing biofilm-mimicking hydrogel from a simulated isthmus model and compare it with sonically- and ultrasonically-activated irrigation systems.<br><br>METHODOLOGY: A polycarbonate root canal model containing two standardized root canals (apical diameter of 0.20&#x2009;mm, 4% taper, 18&#x2009;mm long with a coronal reservoir) connected by three isthmuses (0.40&#x2009;mm deep, 2&#x2009;mm high, 4&#x2009;mm long) was used as the test model. The isthmuses were filled with a hydroxyapatite powder-containing hydrogel. The canals were filled with irrigant, and the models were randomly assigned to the following activation groups (n&#xa0;=&#xa0;15): EndoActivator (EA), ultrasonically-activated irrigation (UAI), and RINSE system (RS). Syringe irrigation (SI) with a 30G needle served as the control. Standardized images of the isthmuses were taken before and after irrigation, and the amount of hydrogel removed was determined using image analysis software and compared across groups using ANOVA (P <&#x2009;0.05).<br><br>RESULTS: Hydrogel removal was significantly higher with the RS (83.7%) than with UAI, EA, or SI (P &#x2264;&#x2009;0.01). UAI (69.2%) removed significantly more hydrogel than SI and EA (P <&#x2009;0.05), while there was no significant difference between SI (24.3%) and EA (25.7%) (P&#xa0;=&#xa0;0.978).<br><br>CONCLUSIONS: RS resulted in the most hydrogel removal, performing better than UAI or EA. The effect of RS was also not reliant on the insert or tip entering the pulp chamber or root canal, making it particularly useful in conservative endodontics.}, }
@article {pmid36824979, year = {2023}, author = {Evans, CR and Smiley, MK and Thio, SA and Wei, M and Price-Whelan, A and Min, W and Dietrich, LEP}, title = {Spatial heterogeneity in biofilm metabolism elicited by local control of phenazine methylation.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.02.15.528762}, pmid = {36824979}, abstract = {UNLABELLED: Within biofilms, gradients of electron acceptors such as oxygen stimulate the formation of physiological subpopulations. This heterogeneity can enable cross-feeding and promote drug resilience, features of the multicellular lifestyle that make biofilm-based infections difficult to treat. The pathogenic bacterium Pseudomonas aeruginosa produces pigments called phenazines that can support metabolic activity in hypoxic/anoxic biofilm subzones, but these compounds also include methylated derivatives that are toxic to their producer under some conditions. Here, we uncover roles for the global regulators RpoS and Hfq/Crc in controlling the beneficial and detrimental effects of methylated phenazines in biofilms. Our results indicate that RpoS controls phenazine methylation by modulating activity of the carbon catabolite repression pathway, in which the Hfq/Crc complex inhibits translation of the phenazine methyltransferase PhzM. We find that RpoS indirectly inhibits expression of CrcZ, a small RNA that binds to and sequesters Hfq/Crc, specifically in the oxic subzone of P. aeruginosa biofilms. Deletion of rpoS or crc therefore leads to overproduction of methylated phenazines, which we show leads to increased metabolic activity-an apparent beneficial effect-in hypoxic/anoxic subpopulations within biofilms. However, we also find that biofilms lacking Crc show increased sensitivity to an exogenously added methylated phenazine, indicating that the increased metabolic activity in this mutant comes at a cost. Together, these results suggest that complex regulation of PhzM allows P. aeruginosa to simultaneously exploit the benefits and limit the toxic effects of methylated phenazines.<br><br>SIGNIFICANCE STATEMENT: P. aeruginosa causes biofilm-based infections and is known for its production of colorful phenazine derivatives. Among these the methylated phenazines are the most toxic and can cause condition-dependent damage to their producer. In this study, we show that methylated phenazines also have a beneficial effect in that they specifically support metabolic activity at depth in P. aeruginosa biofilms, where oxygen limitation would otherwise stall metabolism. We describe a new link between P. aeruginosa global regulators that control methylated phenazine production in a manner that limits their toxicity while simultaneously enabling their contribution to metabolism. These results expand our understanding of the strategies that enable P. aeruginosa survival in multicellular structures, which is key to its success during chronic host colonization.}, }
@article {pmid36824891, year = {2023}, author = {Pastar, I and Dinic, M and Verpile, R and Meng, J and Marjanovic, J and Burgess, J and Plano, L and Hower, S and Thaller, S and Banerjee, S and Lev-Tov, H and Tomic-Canic, M}, title = {Chronic wound microenvironment mediates selection of biofilm-forming multi drug resistant Staphylococcus epidermidis with capability to impair healing.}, journal = {Research square}, volume = {}, number = {}, pages = {}, doi = {10.21203/rs.3.rs-2562300/v1}, pmid = {36824891}, abstract = {Venous leg ulcers (VLU) are the most common chronic wounds characterized by bacterial biofilms and perturbed microbiome. Staphylococcus epidermidis is primarily known as skin commensal beneficial for the host, however, some strains can form biofilms and cause infections. By employing shotgun metagenomic sequencing we show that genetic signatures of antimicrobial resistance, adhesion and biofilm formation in VLU isolates correlate with in vitro bacterial traits. We demonstrate that the capability of chronic wound isolates to form biofilms and elicit IL-8 and IL-1β expression in human ex vivo wounds, correlates with the non-healing outcomes in patients with VLU. In contrast, commensal strains were incapable of surviving in the human ex vivo wounds. We show that major fitness traits of S. epidermis from VLU involve genes for resistance to methicillin and mupirocin, while the biofilm formation relied on the minimal number of genetic elements responsible for bacterial binding to fibronectin and fibrinogen. This underscores the importance of the emergence of treatment resistant virulent lineages in patients with non-healing wounds.}, }
@article {pmid36824066, year = {2023}, author = {Dan, B and Dai, H and Zhou, D and Tong, H and Zhu, M}, title = {Relationship Between Drug Resistance Characteristics and Biofilm Formation in Klebsiella Pneumoniae Strains.}, journal = {Infection and drug resistance}, volume = {16}, number = {}, pages = {985-998}, doi = {10.2147/IDR.S396609}, pmid = {36824066}, issn = {1178-6973}, abstract = {OBJECTIVE: To conduct epidemiological analysis of Klebsiella pneumoniae (K. pneumoniae) with hypervirulence, and to investigate its drug resistance phenotype, Extended-spectrum β-lactamase (ESBLs) gene, virulence factor, capsular serotype and biofilm formation, so as to provide theoretical basis for further understanding of the drug resistance mechanism of K. pneumoniae with hypervirulence.<br><br>METHODS: K. Pneumoniae were isolated from clinical samples collected from inpatients. All strains were identified by VITEK2 Compact using fully automatic microbial analyzer, the minimal inhibitory concentration (MIC) of antibiotics was determined by microbroth dilution test. The double disk diffusion method was used to detect the production of ESBLs, modified carbapenem inactivation method (mCIM) was used to detect the production of carbapenemase, and hypermucoviscosity phenotype was detected by wire drawing test. PCR was used to detect ESBLs gene, virulence factor and capsular serotype. Crystal violet staining was used to detect the ability of biofilm formation.<br><br>RESULTS: The ESBLs genes detected in this study included strains blaTEM 35 (36.5%), blaSHV 51 (53.1%), and blaCTX-M 49 (51.0%). Most strains carried multiple ESBLs genes, but not all of them produce ESBLs. K1 and K2 accounted for 14.6% and 11.5% respectively. Most (91.7%) strains carried the fimH gene, and the other virulence genes were ybtS (53.1%), entB (46.9%), rmpA (41.7%), aerobactin (32.3%), allS (15.6%), kfu (15.6%). Of all the Klebsiella pneumoniae strains, 33 (34.4%) exhibited ESBLs phenotype, 16 (16.7%) were carbapenemase-producing, and 20 (20.8%) with ESBLs phenotype tested were resistant to all four drugs. The correlation between ESBLs-producing strains and biofilm formation was significantly increased compared to strains without ESBLs phenotype (P=0.035).<br><br>CONCLUSION: Compared to hypervirulent Klebsiella pneumoniae (hvKP), classical Klebsiella pneumoniae (cKP) has a tendency to acquire antibiotic resistance. Our study showed that genes encoding rmpA, K1 or K2, and kfu were highly associated with hvKP.}, }
@article {pmid36822111, year = {2023}, author = {Wang, J and Dong, C and Li, Q and Yang, X and Li, D and Zhang, L and Zhang, Y and Zhan, G}, title = {Innovative electrochemical biosensor with nitrifying biofilm and nitrite oxidation signal for comprehensive toxicity detection in Tuojiang River.}, journal = {Water research}, volume = {233}, number = {}, pages = {119757}, doi = {10.1016/j.watres.2023.119757}, pmid = {36822111}, issn = {1879-2448}, abstract = {Water toxicity detection, as a valuable supplement to conventional water quality measurement, is an important method for evaluating water environmental quality standards. However, the toxicity of composite pollutants is more complicated due to their mixture effects. This study developed a novel, rapid and interference-resistant detection method for water toxicity based on an electrochemical biosensor using peak current from nitrite oxidation as a signal. Toxicants could weaken the characteristic peak current of nitrite to indicate the magnitude of toxicity. The proof-of-concept study was first conducted using a synthetic water sample containing trichloroacetic acid (TCAA), and then the results were compared with those of the traditional toxicity colorimetric method (CCK-8 kit) and laser confocal microscopy (CLSM). The accuracy of the biosensor was further verified with water samples containing individual pollutants such as Cd[2+] (50-150 μg/L), Cr[6+] (20-80 μg/L) mixture, triclosan (TCS; 0.1-1.0 μg/L) and TCAA (10-80 μg/L), or a mixture of the above. The viability of the sensor was further validated with the actual water sample from the Tuojiang River. The results demonstrated that although the concentration of a single conventional pollutant in water did not exceed the discharge standard for surface water, the comprehensive toxicity of natural water should not be ignored. This method could be a beneficial supplement to conventional water quality detection to understand the characteristics of the water, and thus contribute to the next stage of water treatment.}, }
@article {pmid36820892, year = {2023}, author = {Krishnan, A and Rajendran, R and Damodaran, D and Manmadhan, SK and Krishnan, V}, title = {Long-term changes in thickness, live/dead bacterial ratio, and mineral content in biofilm on ceramic and stainless steel orthodontic attachments.}, journal = {Journal of orofacial orthopedics = Fortschritte der Kieferorthopadie : Organ/official journal Deutsche Gesellschaft fur Kieferorthopadie}, volume = {}, number = {}, pages = {}, pmid = {36820892}, issn = {1615-6714}, abstract = {PURPOSE: Fixed orthodontic appliances induce biofilm deposition, which harbors a microbial population harmful to the periodontal health of the individual. The present study evaluated the changes in thickness, live/dead bacterial ratio, and mineral content in dental biofilm over 6 months in patients with either stainless steel or ceramic orthodontic attachments.<br><br>METHODS: Eighty patients who require fixed orthodontic appliance treatment with first premolar extraction for correcting their malocclusion were selected and bonded with either stainless steel or ceramic orthodontic attachments on the buccal side. The attached buttons were retrieved at different periods-1&#xa0;week, 1&#xa0;month, 3&#xa0;months, and 6&#xa0;months. They were stained and visualized through confocal microscopy to detect biofilm thickness and the ratio of live/dead bacteria. X&#x2011;ray diffraction was used to identify the presence of calcium and phosphorous.<br><br>RESULTS: Ceramic attachments showed a&#xa0;greater increase in biofilm thickness in comparison to stainless steel attachments except in the initial 1&#x2011;week evaluation. A&#xa0;higher live/dead bacterial ratio was observed in stainless steel attachments than in their ceramic counterparts at all four evaluation periods. Both stainless steel and ceramic surfaces exhibited the presence of mineral deposition (calcium and phosphorous) at all periods.<br><br>CONCLUSIONS: More biofilm adhesion was observed over ceramic surfaces than over stainless steel orthodontic attachments. Stainless steel attachments exhibited biofilm with a&#xa0;higher live/dead bacterial ratio than their ceramic counterparts at all evaluation periods. The presence of calcium and phosphorous in the adhered biofilm, pointing toward its calcification process, was identified.}, }
@article {pmid36819639, year = {2023}, author = {Haniastuti, T and Puspasari, TA and Hakim, ER and Tandelilin, RT}, title = {Potential Effect of Giant Freshwater Prawn Shell Nano Chitosan in Inhibiting the Development of Streptococcus mutans and Streptococcus sanguinis Biofilm In Vitro.}, journal = {International journal of dentistry}, volume = {2023}, number = {}, pages = {8890750}, pmid = {36819639}, issn = {1687-8728}, abstract = {An oral biofilm comprises a variety of bacteria including Streptococcus mutans and Streptococcus sanguinis that cause human infections, such as caries and periodontitis. Thus, biofilm management plays an important part in the prevention and treatment of oral diseases. Nano chitosan is a bioactive material that has antimicrobial activities. This in vitro study aimed to evaluate the effect of nano chitosan synthesized from giant freshwater prawn shells (PSNC) on S. mutans and S. sanguinis biofilm development. PSNC was prepared from the extracted chitosan of giant freshwater prawn (Macrobrachium rosenbergii) shells using the ionic gelation method. The effect of PSNC on S. mutans ATCC 25175 and S. sanguinis ATCC10556 biofilm formation was evaluated using the crystal violet assay. Both bacteria were inoculated in the presence of various concentrations (5, 2.5, and 1.25 mg/ml) of PSNC for 24 h and 48 h. Confocal laser scanning microscopy (CLSM) and scanning electron microscopy were performed to visualize and study the biofilm architectural features. The biofilms were stained with the BacLight Bacterial Viability Kit prior to CLSM observation to monitor the viability of the biofilm. The results showed that PSNC exposure for 24 h and 48 h inhibited the formation of S. mutans and S. sanguinis biofilms. The biofilm formation inhibition percentage increased with an increase in the PSNC concentration (p < 0.05). The highest inhibitory activity was shown at 5 mg/ml PSNC (p < 0.05). Those findings were confirmed by the subsequent findings using the CLSM and SEM analyses. The biofilm architecture was strongly disrupted upon treatment with PSNC. After exposure to 5 mg/ml PSNC, the number of bacteria significantly decreased. The remaining bacteria were seen as individual cells, showing damaged cells. In conclusion, PSNC inhibits the development of S. mutans and S. sanguinis biofilm in vitro, indicating the potential of PSNC in clinical application for oral bacterial infection, prevention, and treatment.}, }
@article {pmid36819068, year = {2023}, author = {Nuppunen-Puputti, M and Kietäväinen, R and Kukkonen, I and Bomberg, M}, title = {Implications of a short carbon pulse on biofilm formation on mica schist in microcosms with deep crystalline bedrock groundwater.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1054084}, pmid = {36819068}, issn = {1664-302X}, abstract = {Microbial life in the deep subsurface occupies rock surfaces as attached communities and biofilms. Previously, epilithic Fennoscandian deep subsurface bacterial communities were shown to host genetic potential, especially for heterotrophy and sulfur cycling. Acetate, methane, and methanol link multiple biogeochemical pathways and thus represent an important carbon and energy source for microorganisms in the deep subsurface. In this study, we examined further how a short pulse of low-molecular-weight carbon compounds impacts the formation and structure of sessile microbial communities on mica schist surfaces over an incubation period of ∼3.5 years in microcosms containing deep subsurface groundwater from the depth of 500 m, from Outokumpu, Finland. The marker gene copy counts in the water and rock phases were estimated with qPCR, which showed that bacteria dominated the mica schist communities with a relatively high proportion of epilithic sulfate-reducing bacteria in all microcosms. The dominant bacterial phyla in the microcosms were Proteobacteria, Firmicutes, and Actinobacteria, whereas most fungal genera belonged to Ascomycota and Basidiomycota. Dissimilarities between planktic and sessile rock surface microbial communities were observed, and the supplied carbon substrates led to variations in the bacterial community composition.}, }
@article {pmid36817722, year = {2023}, author = {Mohamed, A and Raval, YS and Gelston, S and Tibbits, G and Ay, SU and Flurin, L and Greenwood-Quaintance, KE and Patel, R and Beyenal, H}, title = {Anti-Biofilm Activity of a Tunable Hypochlorous Acid-Generating Electrochemical Bandage Controlled By a Wearable Potentiostat.}, journal = {Advanced engineering materials}, volume = {25}, number = {1}, pages = {}, pmid = {36817722}, issn = {1438-1656}, abstract = {Chronic wound biofilm infections represent a major clinical challenge which results in a substantial burden to patients and healthcare systems. Treatment with topical antibiotics is oftentimes ineffective as a result of antibiotic-resistant microorganisms and biofilm-specific antibiotic tolerance. Use of biocides such as hypochlorous acid (HOCl) has gained increasing attention due to the lack of known resistance mechanisms. We designed an HOCl-generating electrochemical bandage (e-bandage) that delivers HOCl continuously at low concentrations targeting infected wound beds in a similar manner to adhesive antimicrobial wound dressings. We developed a battery-operated wearable potentiostat that controls the e-bandage electrodes at potentials suitable for HOCl generation. We demonstrated that e-bandage treatment was tunable by changing the applied potential. HOCl generation on electrode surfaces was verified using microelectrodes. The developed e-bandage showed time-dependent responses against in vitro Acinetobacter baumannii and Staphylococcus aureus biofilms, reducing viable cells to non-detectable levels within 6 and 12 hours of treatment, respectively. The developed e-bandage should be further evaluated as an alternative to topical antibiotics to treat wound biofilm infections.}, }
@article {pmid36816581, year = {2023}, author = {Parga, A and Muras, A and Otero-Casal, P and Arredondo, A and Soler-Ollé, A and Àlvarez, G and Alcaraz, LD and Mira, A and Blanc, V and Otero, A}, title = {The quorum quenching enzyme Aii20J modifies in vitro periodontal biofilm formation.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1118630}, pmid = {36816581}, issn = {2235-2988}, abstract = {INTRODUCTION: Recent studies have revealed the presence of N-acyl-homoserine lactones (AHLs) quorum sensing (QS) signals in the oral environment. Yet, their role in oral biofilm development remains scarcely investigated. The use of quorum quenching (QQ) strategies targeting AHLs has been described as efficient for the control of pathogenic biofilms. Here, we evaluate the use of a highly active AHL-targeting QQ enzyme, Aii20J, to modulate oral biofilm formation in vitro.<br><br>METHODS: The effect of the QQ enzyme was studied in in vitro multispecies biofilms generated from oral samples taken from healthy donors and patients with periodontal disease. Subgingival samples were used as inocula, aiming to select members of the microbiota of the periodontal pocket niche in the in vitro biofilms. Biofilm formation abilities and microbial composition were studied upon treating the biofilms with the QQ enzyme Aii20J.<br><br>RESULTS AND DISCUSSION: The addition of the enzyme resulted in significant biofilm mass reductions in 30 - 60% of the subgingival-derived biofilms, although standard AHLs could not be found in the supernatants of the cultured biofilms. Changes in biofilm mass were not accompanied by significant alterations of bacterial relative abundance at the genus level. The investigation of 125 oral supragingival metagenomes and a synthetic subgingival metagenome revealed a surprisingly high abundance and broad distribution of homologous of the AHL synthase HdtS and several protein families of AHL receptors, as well as an enormous presence of QQ enzymes, pointing to the existence of an intricate signaling network in oral biofilms that has been so far unreported, and should be further investigated. Together, our findings support the use of Aii20J to modulate polymicrobial biofilm formation without changing the microbiome structure of the biofilm. Results in this study suggest that AHLs or AHL-like molecules affect oral biofilm formation, encouraging the application of QQ strategies for oral health improvement, and reinforcing the importance of personalized approaches to oral biofilm control.}, }
@article {pmid36816579, year = {2023}, author = {Sen, P and Gupta, L and Vijay, M and Vermani Sarin, M and Shankar, J and Hameed, S and Vijayaraghavan, P}, title = {4-Allyl-2-methoxyphenol modulates the expression of genes involved in efflux pump, biofilm formation and sterol biosynthesis in azole resistant Aspergillus fumigatus.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1103957}, pmid = {36816579}, issn = {2235-2988}, abstract = {INTRODUCTION: Antifungal therapy for aspergillosis is becoming problematic because of the toxicity of currently available drugs, biofilm formation on host surface, and increasing prevalence of azole resistance in Aspergillus fumigatus. Plants are rich source of bioactive molecules and antimicrobial activity of aromatic bioactive compounds draws attention because of its promising biological properties. The present study elucidated the antibiofilm activity of 4-allyl-2-methoxyphenol (eugenol) against azole-resistant environmental A. fumigatus isolates.<br><br>METHODS: Soil samples were collected from agricultural fields across India; azole-resistant A. fumigatus (ARAF) were isolated followed by their molecular identification. Antibiofilm activity of eugenol was calculated via tetrazolium based-MTT assay. The expression of the multidrug efflux pumps genes MDR1, MDR4, transporters of the MFS gene, erg11A gene encoding 14&#x3b1; demethylase, and transcription regulatory genes, MedA, SomA and SrbA, involved in biofilm formation of A.&#xa0;fumigatus were calculated by quantitative real time PCR.<br><br>RESULTS: Out of 89 A.&#xa0;fumigatus isolates, 10 were identified as azole resistant. Eugenol exhibited antibiofilm activity against ARAF isolates, ranging from 312 to 500 &#xb5;g/mL. Confocal laser scanning microscopy analysis revealed absence of extracellular matrix of ARAF biofilm after eugenol treatment. The gene expression indicated significantly low expression of efflux pumps genes MDR1, MDR4, erg11A and MedA in eugenol treated ARAF isolates when compared with untreated isolates.<br><br>CONCLUSIONS: Our results demonstrate that eugenol effects the expression of efflux pump and biofilm associated genes as well as inhibits biofilm formation in azole resistant isolates of A. fumigatus.}, }
@article {pmid36815575, year = {2023}, author = {Ong, J and Godfrey, R and Nazarian, A and Tam, J and Drake, L and Isaacson, B and Pasquina, P and Williams, D}, title = {Antimicrobial blue light as a biofilm management therapy at the skin-implant interface in an ex vivo percutaneous osseointegrated implant model.}, journal = {Journal of orthopaedic research : official publication of the Orthopaedic Research Society}, volume = {}, number = {}, pages = {}, doi = {10.1002/jor.25535}, pmid = {36815575}, issn = {1554-527X}, abstract = {Biofilm contamination is often present at the skin-implant interface of transfemoral osseointegrated implants leading to frequent infection, irritation, and discomfort. New biofilm management regimens are needed as the current standard of washing the site with soap and water is inadequate to manage infection rates. We have investigated the potential of antimicrobial blue light which has reduced risk of resistance development and broad antimicrobial mechanisms. Our lab has developed an aBL device uniquely designed for an ex vivo system based on an established ovine OI implant model with Staphylococcus aureus ATCC 6538 biofilms as initial inocula. Samples were irradiated with aBL or washed for three consecutive days after which they were quantified. Colony forming unit (CFU) counts were compared to a control group (bacterial inocula without treatment). After one day, aBL administered as a single 6 h dose or two 1 h doses spaced 6 h apart both reduced the CFU count by 1.63 log10 ± .02 CFU. Over three days of treatment, a positive aBL trend was observed with a maximum reduction of ~2.7 log10 CFU following 6 h of treatment, indicating a relation between multiple days of irradiation and greater CFU reductions. aBL was more effective at reducing the biofilm burden at the skin-implant interface compared to the wash group, demonstrating the potential of aBL as a biofilm management option. This article is protected by copyright. All rights reserved.}, }
@article {pmid36812964, year = {2023}, author = {Sun, X and Yu, J and Wei, Q and Ren, X}, title = {Construction of chitosan-based supramolecular biofilm material for wound dressing based on natural deep eutectic solvents.}, journal = {International journal of biological macromolecules}, volume = {}, number = {}, pages = {123768}, doi = {10.1016/j.ijbiomac.2023.123768}, pmid = {36812964}, issn = {1879-0003}, abstract = {Bacterial infection is still one of the main problems observed in the clinical process of wound healing, so the development of new multifunctional biocompatible materials is an urgent clinical need. A kind of supramolecular biofilm crosslinked by hydrogen bond between natural deep eutectic solvent and chitosan was studied and successfully prepared to reduce bacterial infection. Its killing rates of Staphylococcus aureus and Escherichia coli can reach 98.86 % ± 1.90 % and 99.69 % ± 0.53 %, and it can be degraded in both soil and water, showing excellent biocompatibility and biodegradability. In addition, the supramolecular biofilm material also has the UV barrier property, which can effectively avoid the secondary injury of UV to the wound. Interestingly, the cross-linking effect of hydrogen bond makes the biofilm have a more compact structure and rough surface, and gives the biofilm strong tensile properties. Overall, owing to these unique advantages, NADES-CS supramolecular biofilm has great potential for medical applications, laying the foundation for the realization of sustainable polysaccharide materials.}, }
@article {pmid36812218, year = {2023}, author = {Gallingani, T and Resca, E and Dominici, M and Gavioli, G and Laurita, R and Liguori, A and Mari, G and Ortolani, L and Pericolini, E and Sala, A and Laghi, G and Petrachi, T and Arnauld, GF and Accorsi, L and Rizzoli, R and Colombo, V and Gherardi, M and Veronesi, E}, title = {A new strategy to prevent biofilm and clot formation in medical devices: The use of atmospheric non-thermal plasma assisted deposition of silver-based nanostructured coatings.}, journal = {PloS one}, volume = {18}, number = {2}, pages = {e0282059}, pmid = {36812218}, issn = {1932-6203}, abstract = {In industrialized countries, health care associated infections, the fourth leading cause of disease, are a major health issue. At least half of all cases of nosocomial infections are associated with medical devices. Antibacterial coatings arise as an important approach to restrict the nosocomial infection rate without side effects and the development of antibiotic resistance. Beside nosocomial infections, clot formation affects cardiovascular medical devices and central venous catheters implants. In order to reduce and prevent such infection, we develop a plasma-assisted process for the deposition of nanostructured functional coatings on flat substrates and mini catheters. Silver nanoparticles (Ag NPs) are synthesized exploiting in-flight plasma-droplet reactions and are embedded in an organic coating deposited through hexamethyldisiloxane (HMDSO) plasma assisted polymerization. Coating stability upon liquid immersion and ethylene oxide (EtO) sterilization is assessed through chemical and morphological analysis carried out by means of Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). In the perspective of future clinical application, an in vitro analysis of anti-biofilm effect has been done. Moreover, we employed a murine model of catheter-associated infection which further highlighted the performance of Ag nanostructured films in counteract biofilm formation. The anti-clot performances coupled by haemo- and cytocompatibility assays have also been performed.}, }
@article {pmid36811771, year = {2023}, author = {Ikome, HN and Tamfu, AN and Abdou, JP and Fouotsa, H and Nangmo, PK and Lah, FCW and Tchinda, AT and Ceylan, O and Frederich, M and Nkengfack, AE}, title = {Disruption of Biofilm Formation and Quorum Sensing in Pathogenic Bacteria by Compounds from Zanthoxylum Gilletti (De Wild) P.G. Waterman.}, journal = {Applied biochemistry and biotechnology}, volume = {}, number = {}, pages = {}, pmid = {36811771}, issn = {1559-0291}, abstract = {Microbial resistance is facilitated by biofilm formation and quorum-sensing mediated processes. In this work, the stem bark (ZM) and fruit extracts (ZMFT) of Zanthoxylum gilletii were subjected to column chromatography and afforded lupeol (1), 2,3-epoxy-6,7-methylenedioxyconiferyl alcohol (3), nitidine chloride (4), nitidine (7), sucrose (6) and sitosterol-β-D-glucopyranoside (2). The compounds were characterized using MS and NMR spectral data. The samples were evaluated for antimicrobial, antibiofilm and anti-quorum sensing activities. Highest antimicrobial activity was exhibited by compounds 3, 4 and 7 against Staphylococcus aureus (MIC 200 µg/mL), compounds 3 and 4 against Escherichia coli (MIC = 100 µg/mL) and compounds 4 and 7 against Candida albicans (MIC = 50 µg/mL). At MIC and sub-MIC concentrations, all samples inhibited biofilm formation by pathogens and violacein production in C. violaceum CV12472 except compound 6. Good disruption of QS-sensing in C. violaceum revealed by inhibition zone diameters were exhibited by compounds 3 (11.5 ± 0.5 mm), 4 (12.5 ± 1.5 mm), 5 (15.0 ± 0.8 mm), 7 (12.0 ± 1.5 mm) as well as the crude extracts from stem barks (16.5 ± 1.2 mm) and seeds (13.0 ± 1.4 mm). The profound inhibition of quorum sensing mediated processes in test pathogens by compounds 3, 4, 5 and 7 suggests the methylenedioxy- group that these compounds possess as the possible pharmacophore.}, }
@article {pmid36814951, year = {2019}, author = {Shadmehr, E and Davoudi, A and Damoon Sarmast, N and Saatchi, M}, title = {Evaluation of Antimicrobial Effcacy of Calcium Hypochlorite as an Endodontic Irrigant on a Mixed-Culture Biofilm: An Ex vivo Study.}, journal = {Iranian endodontic journal}, volume = {14}, number = {3}, pages = {178-184}, pmid = {36814951}, issn = {2008-2746}, abstract = {INTRODUCTION: Calcium hypochlorite (CH) has been recently suggested as an endodontic irrigant. The aim of this investigation was to evaluate the antimicrobial efficacy of CH compared to sodium hypochlorite (NaOCl) and chlorhexidine (CHX) against multispecies biofilm in surface and deep dentinal tubules.<br><br>METHODS AND MATERIALS: Minimal inhibitory concentration (MIC) of irrigant agents was assessed using a microdilution method. One hundred and twenty of human maxillary incisor teeth were prepared and infected with suspension of Entrococcus faecalis, Fusobacterium nucleatum and Prevotella intermedia in an anaerobic jar for 7 days. Depending on irrigation solutions, specimens were divided into 4 groups (n=30); group 1: 2% CHX, group 2: 5.25% sodium hypochlorite, group 3: 5% calcium hypochlorite, group 4: positive control (normal saline (NS)). Fifteen remained specimens were used as negative control. Surviving bacteria were sampled before (S1) and after irrigation from surface (S2) and deep (S3) dentin. The medium turbidity was visualized with spectrophotometry. Data were analyzed using analysis of variance followed by Tukey post hoc test (&#x3b1;=0.05).<br><br>RESULTS: The MIC of CH against E. faecalis, F. nucleatum and P. intermedia was 25, 8 and 7.5 &#xb5;g/mL respectively. There were no significant differences in S1 among the test groups. Moreover, 2% CHX and 5% CH had significantly lower medium turbidity at both S2 and S3, in comparison with 5.25% NaOCl (P=0.018 and 0.031, respectively). But there were no significant differences between 2% CHX and 5% CH at both S2 and S3 (P=0.862 and 0.978, respectively).<br><br>CONCLUSION: Under the conditions of this ex vivo study, 5% CH and 2% CHX are more effective than 5.25% NaOCl in the reduction of mixed-culture biofilm.}, }
@article {pmid36811769, year = {2023}, author = {Machado, MAM and Castro, VS and da Cunha-Neto, A and Vallim, DC and Pereira, RCL and Dos Reis, JO and de Almeida, PV and Galvan, D and Conte-Junior, CA and Figueiredo, EES}, title = {Heat-resistant and biofilm-forming Escherichia coli in pasteurized milk from Brazil.}, journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]}, volume = {}, number = {}, pages = {}, pmid = {36811769}, issn = {1678-4405}, abstract = {Escherichia coli harboring a transmissible locus of stress tolerance (tLST) and the ability to form biofilms represent a serious risk in dairy production. Thus, we aimed to evaluate the microbiological quality of pasteurized milk from two dairy producers in Mato Grosso, Brazil, with a focus on determining the possible presence of E. coli with heat resistance (60 °C/6 min), biofilm-forming potential phenotypes and genotypes, and antimicrobial susceptibility. For this, fifty pasteurized milk samples from producers named A and B were obtained for 5 weeks to investigate the presence of Enterobacteriaceae members, coliforms, and E. coli. For heat resistance, E. coli isolates were exposed to a water bath at 60 °C for 0 and 6 min. In antibiogram analysis, eight antibiotics belonging to six antimicrobial classes were analyzed. The potential to form biofilms was quantified at 570 nm, and curli expression by Congo Red was analyzed. To determine the genotypic profile, we performed PCR for the tLST and rpoS genes, and pulsed-field gel electrophoresis (PFGE) was used to investigate the clonal profile of the isolates. Thus, producer A presented unsatisfactory microbiological conditions regarding Enterobacteriaceae and coliforms for weeks 4 and 5, while all samples analyzed for producer B were contaminated at above-the-limit levels established by national and international legislation. These unsatisfactory conditions enabled us to isolate 31 E. coli from both producers (7 isolates from producer A and 24 isolates from producer B). In this way, 6 E. coli isolates (5 from producer A and 1 from producer B) were highly heat resistant. However, although only 6 E. coli showed a highly heat-resistant profile, 97% (30/31) of all E. coli were tLST-positive. In contrast, all isolates were sensitive to all antimicrobials tested. In addition, moderate or weak biofilm potential was verified in 51.6% (16/31), and the expression of curli and presence of rpoS was not always related to this biofilm potential. Therefore, the results emphasize the spreading of heat-resistant E. coli with tLST in both producers and indicate the biofilm as a possible source of contamination during milk pasteurization. However, the possibility of E. coli producing biofilm and surviving pasteurization temperatures cannot be ruled out, and this should be investigated.}, }
@article {pmid36811767, year = {2023}, author = {Santos, PR and Kraus, RB and Ladeira, SL and Pereira, GM and Cunha, KF and Palhares, KE and Silva, ACA and Dors, GC and Lima, HG and Cereser, ND and Nascente, PS}, title = {Resistance profile and biofilm production of Enterococcus spp., Staphylococcus sp., and Streptococcus spp. from dairy farms in southern Brazil.}, journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]}, volume = {}, number = {}, pages = {}, pmid = {36811767}, issn = {1678-4405}, abstract = {Milk is a high nutritional value food that helps in human development and growth. However, it can also harbor microorganisms. Therefore, the objective of this study was to isolate, identify and evaluate the resistance profile and pathogenicity factors of gram-positive cocci isolated from liners in milking rooms in the south of Rio Grande do Sul, Brazil. Biochemical and molecular tests were performed for the identification. The following were isolated: Enterococcus faecalis (10), Enterococcus faecium (4), Staphylococcus intermedius (1), Streptococcus uberis (1), and Streptococcus dysgalactiae (1). The susceptibility of isolated microorganisms to eight antibiotics was evaluated according to CLSI, and the genus that proved to be resistant to most of those was Enterococcus. In addition, all 17 isolates were able to form biofilm, which remained viable after the use of neutral, alkaline and alkaline-chlorinated detergent. The only product that was effective against biofilm of all microorganisms was chlorhexidine 2%. The results obtained highlight the importance of pre- and post-dipping tests on dairy properties, in which chlorhexidine is one of the disinfectants used. As observed, products indicated for cleaning and descaling pipes were not effective on biofilms of the different species tested.}, }
@article {pmid36811095, year = {2023}, author = {Wang, Y and Lv, Q and Chen, Y and Xu, L and Feng, M and Xiong, Z and Li, J and Ren, J and Liu, J and Liu, B}, title = {Bilayer hydrogel dressing with lysozyme-enhanced photothermal therapy for biofilm eradication and accelerated chronic wound repair.}, journal = {Acta pharmaceutica Sinica. B}, volume = {13}, number = {1}, pages = {284-297}, doi = {10.1016/j.apsb.2022.03.024}, pmid = {36811095}, issn = {2211-3835}, abstract = {Biofilms are closely associated with the tough healing and dysfunctional inflammation of chronic wounds. Photothermal therapy (PTT) emerged as a suitable alternative which could destroy the structure of biofilms with local physical heat. However, the efficacy of PTT is limited because the excessive hyperthermia could damage surrounding tissues. Besides, the difficult reserve and delivery of photothermal agents makes PTT hard to eradicate biofilms as expectation. Herein, we present a GelMA-EGF/Gelatin-MPDA-LZM bilayer hydrogel dressing to perform lysozyme-enhanced PTT for biofilms eradication and a further acceleration to the repair of chronic wounds. Gelatin was used as inner layer hydrogel to reserve lysozyme (LZM) loaded mesoporous polydopamine (MPDA) (MPDA-LZM) nanoparticles, which could rapidly liquefy while temperature rising so as to achieve a bulk release of nanoparticles. MPDA-LZM nanoparticles serve as photothermal agents with antibacterial capability, could deeply penetrate and destroy biofilms. In addition, the outer layer hydrogel consisted of gelatin methacryloyl (GelMA) and epidermal growth factor (EGF) promoted wound healing and tissue regeneration. It displayed remarkable efficacy on alleviating infection and accelerating wound healing in vivo. Overall, the innovative therapeutic strategy we came up with has significant effect on biofilms eradication and shows promising application in promoting the repair of clinical chronic wounds.}, }
@article {pmid36810960, year = {2023}, author = {Mohanasundaram, P and Saral, M}, title = {Phytochemical Screening, Anti-bacterial, Anti-fungal, Anti-biofilm and Anti-oxidant Activity of Azadirachta Indica A Juss Flowers.}, journal = {Chemistry &amp; biodiversity}, volume = {}, number = {}, pages = {e202201049}, doi = {10.1002/cbdv.202201049}, pmid = {36810960}, issn = {1612-1880}, abstract = {The present study involves investigation of Pharmacognostic properties, phytochemicals, anti-oxidant, anti-biofilm, and anti-microbial activities of Azadirachta Indica A Juss Flower extracts. The Pharmacognostic characteristics were evaluated with respect to moisture content, total ash content, acid, and water-soluble ash content, swelling index, foaming index, and metal content. The macro and micronutrient content of the crude drug was estimated by AAS and Flame photometric methods and it gives the quantitative estimation of minerals, where calcium is present in abundance (88.64 mg/L). Soxhlet extraction was carried out in the increasing order of polarity of the solvent viz Petroleum Ether (PE), Acetone (AC), and Hydroalcohol (20%) (HA). The antioxidant activity of the extracts was evaluated by DPPH, FRAP, and Phosopomolybdenum assay. This reveals that HA extract shows good scavenging activity than PE and AC extracts which is well correlated with the bioactive compounds, especially phenols which are present as a major component in the extract. The anti-microbial activity was investigated via Agar well diffusion method for all the extracts. Among all the extracts HA extract shows good antibacterial activity with MIC of 25 µg/mL and AC extract shows good anti-fungal activity with MIC of 25 µg/mL. The antibiofilm assay confirms that the HA extract shows good biofilm inhibition about 94% among other extracts on human pathogens. The results confirm that the HA extract of A. Indica flowers will be an excellent source of natural anti-oxidant and also antimicrobial agents. This paves the way for its potential uses in herbal product formulation.}, }
@article {pmid36810950, year = {2023}, author = {Zhang, JJ and Feng, YM and Zhang, JR and Xiao, WL and Liu, SS and Zhou, X and Zhang, H and Wang, PY and Liu, LW and Yang, S}, title = {Resistance-driven innovations in the discovery of bactericides: novel triclosan derivatives decorating isopropanolamine moiety as promising anti-biofilm agents against destructive plant bacterial diseases.}, journal = {Pest management science}, volume = {}, number = {}, pages = {}, doi = {10.1002/ps.7419}, pmid = {36810950}, issn = {1526-4998}, abstract = {BACKGROUND: Controlling bacterial infections in plants is a major challenge due to the appearance of resistant strains. As a physical barrier, the bacterial biofilm helps bacterial infections acquire drug resistance by enabling bacteria to accommodate complex and volatile environmental conditions and avoid bactericides' effects. Thus, developing new antibacterial agents with antibiofilm potency is imperative.<br><br>RESULTS: A series of simple triclosan derivatives containing isopropanolamine moiety were elaborately designed and assessed for antibacterial behavior. Bioassay results showed that some title compounds had excellent bioactivity against three destructive bacteria Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas axonopodis pv. citri (Xac), and Pseudomonas syringae pv. actinidiae (Psa). Notably, compound C8 displayed high bioactivities toward Xoo and Xac, the related EC50 values were 0.34 and 2.11 &#x3bc;g mL[-1] , respectively. In vivo trials revealed that compound C8 exhibited excellent protective activities against rice bacterial blight and citrus bacterial canker at 200 &#x3bc;g mL[-1] , with a control effectiveness of 49.57% and 85.60%, respectively. Compound A4 had remarkably inhibitory activity toward Psa, with an EC50 value of 2.63 &#x3bc;g mL[-1] , and demonstrated outstanding protective activity with a value of 77.23% against Psa in vivo. Antibacterial mechanisms indicated that compound C8 dose-dependently prevented biofilm formation and extracellular polysaccharide production. C8 also significantly weakened the motility and pathogenicity of Xoo.<br><br>CONCLUSION: This study contributes to the development and excavation of novel bactericidal candidates with broad-spectrum antibacterial activity by targeting bacterial biofilm to control refractory plant bacterial diseases. This article is protected by copyright. All rights reserved.}, }
@article {pmid36810656, year = {2023}, author = {Zhang, J and Qi, H and Wang, M and Wei, Y and Liang, H}, title = {Enzymatically hydrolyzed sodium caseinate nanoparticles efficiently enhancing the solubility, stability, and antioxidant and anti-biofilm activities of hydrophobic Tanshinone IIA.}, journal = {Journal of materials chemistry. B}, volume = {}, number = {}, pages = {}, doi = {10.1039/d2tb02263j}, pmid = {36810656}, issn = {2050-7518}, abstract = {Enzymatic hydrolysis has been validated as an appropriate strategy for improving the properties of natural protein. Here, we used enzymatic hydrolysis sodium caseinate (Eh NaCas) as a nano-carrier for enhancing the solubility, stability, and antioxidant and anti-biofilm activities of hydrophobic encapsulants. Tanshinone IIA (TA) was loaded into the hydrophobic regions of Eh NaCas by self-assembly, and the encapsulation efficiency could reach 96.54 ± 0.14% under an optimized host-guest ratio. After Eh NaCas packed, the TA-loaded Eh NaCas nanoparticles (Eh NaCas@TA) showed regular spheres, uniform particle size distribution and more optimal drug release. Moreover, the solubility of TA in aqueous solution increased over 2.4 × 10[5] times, and the TA guest molecules displayed excellent stability under light and other harsh environments. Interestingly, the vehicle protein and TA exhibited synergistic antioxidant effects. Furthermore, Eh NaCas@TA forcefully restrained the growth and destroyed the biofilm construction of Streptococcus mutans compared to free TA, showing positive antibacterial activity. The establishment of these results demonstrated the feasibility and functionality of edible protein hydrolysates as nano-carriers for loading natural plant hydrophobic extracts.}, }
@article {pmid36810410, year = {2023}, author = {Messersmith, RE and Sage, FC and Johnson, JK and Langevin, SA and Forsyth, ER and Hart, MT and Hoffman, CM}, title = {Iron Sequestration by Galloyl-Silane Nano Coatings Inhibits Biofilm Formation of Sulfitobacter sp.}, journal = {Biomimetics (Basel, Switzerland)}, volume = {8}, number = {1}, pages = {}, doi = {10.3390/biomimetics8010079}, pmid = {36810410}, issn = {2313-7673}, abstract = {Microbially-induced corrosion is the acceleration of corrosion induced by bacterial biofilms. The bacteria in the biofilms oxidize metals on the surface, especially evident with iron, to drive metabolic activity and reduce inorganic species such as nitrates and sulfates. Coatings that prevent the formation of these corrosion-inducing biofilms significantly increase the service life of submerged materials and significantly decrease maintenance costs. One species in particular, a member of the Roseobacter clade, Sulfitobacter sp., has demonstrated iron-dependent biofilm formation in marine environments. We have found that compounds that contain the galloyl moiety can prevent Sulfitobacter sp. biofilm formation by sequestering iron, thus making a surface unappealing for bacteria. Herein, we have fabricated surfaces with exposed galloyl groups to test the effectiveness of nutrient reduction in iron-rich media as a non-toxic method to reduce biofilm formation.}, }
@article {pmid36809809, year = {2023}, author = {Aias, M and Azrad, M and Saad, G and Leshem, T and Hamo, Z and Rahmoun, LA and Peretz, A}, title = {Different bile acids have versatile effects on sporulation, toxin levels and biofilm formation of different Clostridioides difficile strains.}, journal = {Journal of microbiological methods}, volume = {}, number = {}, pages = {106692}, doi = {10.1016/j.mimet.2023.106692}, pmid = {36809809}, issn = {1872-8359}, abstract = {Clostridioides difficile infection develops following ingestion of virulent stains by a susceptible host. Once germinated, toxins TcdA and TcdB, and in some of the strains binary toxin, are secreted, eliciting disease. Bile acids play a significant role in the process of spore germination and outgrowth, with cholate and its derivative enhancing colony formation, while chenodeoxycholate inhibit germination and outgrowth. This work investigated bile acids' impact on spore germination, toxin levels and biofilm formation in various strain types (STs). Thirty C. difficile isolates (A[+] B[+] CDT[-\+]) of different STs were exposed to increasing concentrations of the bile acids, cholic acid (CA), taurocholic acid (TCA) and chenodeoxycholic acid (CDCA). Following treatments, spore germination was determined. Toxin concentrations were semi-quantified using the C. Diff Tox A/B II™ kit. Biofilm formation was detected by the microplate assay with crystal violet. SYTO® 9 and propidium iodide staining were used for live and dead cell detection, respectively, inside the biofilm. Toxins levels were increased by 1.5-28-fold in response to CA and by 1.5-20-fold in response to TCA, and decreased by 1-37-fold due to CDCA exposure. CA had a concentration-dependent effect on biofilm formation, with the low concentration (0.1%) inducing- and the higher concentrations inhibiting biofilm formation, while CDCA significantly reduced biofilm production at all concentrations. There were no differences in the bile acids effects on different STs. Further investigation might identify a specific bile acids' combination with inhibitory effects on C. difficile toxin and biofilm production, which could modulate toxin formation to reduce the likelihood of developing CDI.}, }
@article {pmid36809632, year = {2023}, author = {Xin, C and Wang, F and Zhang, J and Zhou, Q and Liu, F and Zhao, C and Song, Z}, title = {Secretions from Serratia marcescens Inhibit the Growth and Biofilm Formation of Candida spp. and Cryptococcus neoformans.}, journal = {Journal of microbiology (Seoul, Korea)}, volume = {}, number = {}, pages = {}, pmid = {36809632}, issn = {1976-3794}, abstract = {Candida spp. and Cryptococcus are conditional pathogenic fungi that commonly infect immunocompromised patients. Over the past few decades, the increase in antifungal resistance has prompted the development of new antifungal agents. In this study, we explored the potential antifungal effects of secretions from Serratia marcescens on Candida spp. and Cryptococcus neoformans. We confirmed that the supernatant of S. marcescens inhibited fungal growth, suppressed hyphal and biofilm formation, and downregulated the expression of hyphae-specific genes and virulence-related genes in Candida spp. and C. neoformans. Furthermore, the S. marcescens supernatant retained biological stability after heat, pH, and protease K treatment. The chemical profile of the S. marcescens supernatant was characterized by ultra-high-performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry analysis and a total of 61 compounds with an mzCloud best match of greater than 70 were identified. In vivo, treatment with the S. marcescens supernatant reduced the mortality of fungi-infected Galleria mellonella. Taken together, our results revealed that the stable antifungal substances in the supernatant of S. marcescens have promising potential applications in the development of new antifungal agents.}, }
@article {pmid36809069, year = {2023}, author = {de Souza, CM and Moreira Dos Santos, M and Furlaneto-Maia, L and Furlaneto, MC}, title = {Adhesion and biofilm formation by the opportunistic pathogen Candida tropicalis: what do we know?.}, journal = {Canadian journal of microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1139/cjm-2022-0195}, pmid = {36809069}, issn = {1480-3275}, abstract = {Candida tropicalis is among the most important Candida species in terms of epidemiology, virulence and resistance. Considering the increase in C. tropicalis incidence and high rates of mortality associated with this species, knowledge of its adhesion and biofilm formation abilities is needed. These traits determine the persistence and survival of yeast on different indwelling medical devices and host sites. C. tropicalis is among the most adherent Candida species, and it has been described as a strong biofilm producer. Environmental factors, phenotypic switching and quorum sensing molecules can affect adhesion and biofilm growth. C. tropicalis can form sexual biofilms, which are promoted by mating pheromones. C. tropicalis biofilms are regulated by a wide and complex network of genes and signaling pathways that are currently poorly understood. Morphological studies showed improved biofilm architecture, which was related to the expression of several hypha-specific genes. Based on recent updates, research is still needed to increase our knowledge on the genetic network of adhesion and biofilm formation by C. tropicalis, as well as the protein diversity that mediates interactions with inert materials and biological surfaces. Here, we have reviewed the main aspects related to adhesion and biofilm formation in C. tropicalis and summarized current knowledge on the significance of these virulence factors in this opportunistic species.}, }
@article {pmid36809043, year = {2023}, author = {Buzza, KM and Pluen, A and Doherty, C and Cheesapcharoen, T and Singh, G and Ledder, RG and Sreenivasan, PK and McBain, AJ}, title = {Modulation of Biofilm Formation and Permeability in Streptococcus mutans during Exposure To Zinc Acetate.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0252722}, doi = {10.1128/spectrum.02527-22}, pmid = {36809043}, issn = {2165-0497}, abstract = {The penetration of biofilms by antimicrobials is a potential limiting factor in biofilm control. This is relevant to oral health, as compounds that are used to control microbial growth and activities could also affect the permeability of dental plaque biofilm with secondary effects on biofilm tolerance. We investigated the effects of zinc salts on the permeability of Streptococcus mutans biofilms. Biofilms were grown with low concentrations of zinc acetate (ZA), and a transwell transportation assay was applied to test biofilm permeability in an apical-basolateral direction. Crystal violet assays and total viable counts were used to quantify the biofilm formation and viability, respectively, and short time frame diffusion rates within microcolonies were determined using spatial intensity distribution analysis (SpIDA). While the diffusion rates within biofilm microcolonies were not significantly altered, exposure to ZA significantly increased the overall permeability of S. mutans biofilms (P < 0.05) through decreased biofilm formation, particularly at concentrations above 0.3 mg/mL. Transport was significantly lower through biofilms grown in high sucrose conditions. IMPORTANCE Zinc salts are added to dentifrices to improve oral hygiene through the control of dental plaque. We describe a method for determining biofilm permeability and show a moderate inhibitory effect of zinc acetate on biofilm formation, and that this inhibitory effect is associated with increases in overall biofilm permeability.}, }
@article {pmid36808649, year = {2023}, author = {Ghasemian, S and Karami-Zarandi, M and Heidari, H and Khoshnood, S and Kouhsari, E and Ghafourian, S and Maleki, A and Kazemian, H}, title = {Molecular characterizations of antibiotic resistance, biofilm formation, and virulence determinants of Pseudomonas aeruginosa isolated from burn wound infection.}, journal = {Journal of clinical laboratory analysis}, volume = {}, number = {}, pages = {e24850}, doi = {10.1002/jcla.24850}, pmid = {36808649}, issn = {1098-2825}, abstract = {BACKGROUND: Burn injuries result in disruption of the skin barrier against opportunistic infections. Pseudomonas aeruginosa is one of the main infectious agents colonizing burn wounds and making severe infections. Biofilm production and other virulence factors along with antibiotic resistance limit appropriate treatment options and time.<br><br>MATERIALS AND METHODS: Wound samples were collected from hospitalized burn patients. P.&#xa0;aeruginosa isolates and related virulence factors identified by the standard biochemical and molecular methods. Antibiotic resistance patterns were determined by the disc diffusion method and &#x3b2;-lactamase genes were detected by polymerase chain reaction (PCR) assay. To determine the genetic relatedness amongst the isolates, enterobacterial repetitive intergenic consensus (ERIC)-PCR was also performed.<br><br>RESULTS: Forty P.&#xa0;aeruginosa isolates were identified. All of these isolates were biofilm producers. Carbapenem resistance was detected in 40% of the isolates, and blaTEM (37/5%), blaVIM (30%), and blaCTX-M (20%) were the most common &#x3b2;-lactamase genes. The highest resistance was detected to cefotaxime, ceftazidime, meropenem, imipenem and piperacillin, and 16 (40%) isolates were resistant to these antibiotics. The minimum inhibitory concentrations (MIC) of colistin was lower than 2&#xa0;&#x3bc;g/mL and no resistance was observed. Isolates were categorized to 17 MDR, 13 mono-drug resistance, and 10 susceptible isolates. High genetic diversity was also observed among the isolates (28 ERIC types) and most carbapenem-resistant isolates were classified into four main types.<br><br>CONCLUSION: Antibiotic resistance, particularly carbapenem resistance was considerable among the P.&#xa0;aeruginosa isolates colonizing burn wounds. Combining carbapenem resistance with biofilm production and virulence factors would result in severe and difficult-to-treat infections.}, }
@article {pmid36807839, year = {2023}, author = {Hijazi, DM and Dahabiyeh, LA and Abdelrazig, S and Alqudah, DA and Al-Bakri, AG}, title = {Micafungin effect on Pseudomonas aeruginosa metabolome, virulence and biofilm: potential quorum sensing inhibitor.}, journal = {AMB Express}, volume = {13}, number = {1}, pages = {20}, pmid = {36807839}, issn = {2191-0855}, abstract = {The prevalence of antibiotic resistance in Pseudomonas aeruginosa places a heavy burden on the health care sectors urging the need to find alternative, non-antibiotic strategies. The interference with the P. aeruginosa quorum sensing (QS) system represents a promising alternative strategy to attenuate the bacterial virulency and its ability to form biofilms. Micafungin has been reported to impede the pseudomonal biofilm formation. However, the influences of micafungin on the biochemical composition and metabolites levels of P. aeruginosa have not been explored. In this study, the effect of micafungin (100 µg/mL) on the virulence factors, QS signal molecules and the metabolome of P. aeruginosa was studied using exofactor assay and mass spectrometry-based metabolomics approaches. Furthermore, confocal laser scanning microscopy (CLSM) using the fluorescent dyes ConA-FITC and SYPRO® Ruby was used to visualize micafungin disturbing effects on the pseudomonal glycocalyx and protein biofilm-constituents, respectively. Our findings showed that micafungin significantly decreased the production of various QS-controlled virulence factors (pyocyanin, pyoverdine, pyochelin and rhamnolipid), along with a dysregulation in the level of various metabolites involved in QS system, lysine degradation, tryptophan biosynthesis, TCA cycle, and biotin metabolism. In addition, the CLSM examination showed an altered matrix distribution. The presented findings highlight the promising role of micafungin as a potential quorum sensing inhibitor (QSI) and anti-biofilm agent to attenuate P. aeruginosa pathogenicity. In addition, they point to the promising role of metabolomics study in investigating the altered biochemical pathways in P. aeruginosa.}, }
@article {pmid36807459, year = {2023}, author = {Lara, BR and de Camargo, BB and Paula, CR and de Morais Monari, GP and Garces, HG and Arnoni, MV and Silveira, M and Gimenes, VMF and Junior, DPL and Bonfietti, LX and Oliveira, L and de Souza Carvalho Melhem, M and Auler, M and Ramos, RTB and Dias, ALT and Silva, NC and Moreira, D and Richini-Pereira, VB and Anversa, L and da Silva Ruiz, L}, title = {Aspects related to biofilm production and antifungal susceptibility of clinically relevant yeasts of the genus Trichosporon.}, journal = {Medical mycology}, volume = {}, number = {}, pages = {}, doi = {10.1093/mmy/myad022}, pmid = {36807459}, issn = {1460-2709}, abstract = {Trichosporonosis corresponds to a systemic fungal disease that leads to high mortality rates and is frequently associated with medical devices. It affects immunosuppressed patients in particular and is strongly linked to acquired human immunodeficiency, organ and tissue transplants and malignant hematologic diseases such as leukemia and lymphomas. Trichosporon infections have been increasingly reported worldwide; however, little information is available either about their characteristics or about the causative microorganism. Thus, the aims of the present study were: to investigate 59 yeasts of the genus Trichosporon by verifying the biofilm formation capacity of isolates; to analyze the susceptibility patterns of planktonic cells against the antifungals fluconazole, itraconazole, amphotericin-B, voriconazole and caspofungin by comparing European Committee for Antimicrobial Susceptibility Testing (EUCAST) broth microdilution technique with the commercial method Etest, and to assess the susceptibility patterns of biofilm cells (sessile) against the same antifungals through broth microdilution. The ability to form biofilm on the surface of polystyrene plates was noted for all isolates, and 54.3% samples were considered strong producers. Comparison between the antifungal susceptibility techniques evidenced that Etest showed higher and discordant MICs from those obtained by the microdilution method, especially for fluconazole, itraconazole and caspofungin. Considering the susceptibility of biofilms, most species had high MIC50 and MIC90 against the tested antifungals, showing 4-to-66-fold higher concentrations for amphotericin B and 2-to-33-fold greater concentrations for caspofungin. These results highlight the importance of further studies with Trichosporon spp. for comparison between laboratory findings and in vivo response, considering both the susceptibility tests and the behavior of biofilm cells against drugs.}, }
@article {pmid36807047, year = {2023}, author = {Delacuvellerie, A and Brusselman, A and Cyriaque, V and Benali, S and Moins, S and Raquez, JM and Gobert, S and Wattiez, R}, title = {Long-term immersion of compostable plastics in marine aquarium: Microbial biofilm evolution and polymer degradation.}, journal = {Marine pollution bulletin}, volume = {189}, number = {}, pages = {114711}, doi = {10.1016/j.marpolbul.2023.114711}, pmid = {36807047}, issn = {1879-3363}, abstract = {The best-selling compostable plastics, polylactic acid (PLA) and polybutylene adipate-co-terephthalate (PBAT), can accidentally end up in the marine environment due to plastic waste mismanagement. Their degradation and colonization by microbial communities are poorly documented in marine conditions. To better understand their degradation, as well as the dynamics of bacterial colonization after a long immersion time (99, 160, and 260 days), PBAT, semicrystalline, and amorphous PLA films were immersed in a marine aquarium. Sequencing and chemical analyses were used in parallel to characterize these samples. Despite the variation in the chemical intrinsic parameters of these plastics, their degradation remains very slow. Microbial community structure varied according to the immersion time with a high proportion of Archaea. Moreover, the plastisphere structure of PBAT was specific. A better understanding of compostable plastic degradability is crucial to evaluate their impact on ecosystems and to eco-design new recyclable plastics with optimal degradation properties.}, }
@article {pmid36807004, year = {2023}, author = {Toliopoulos, C and Giaouris, E}, title = {Marked inter-strain heterogeneity in the differential expression of some key stress response and virulence-related genes between planktonic and biofilm cells in Listeria monocytogenes.}, journal = {International journal of food microbiology}, volume = {390}, number = {}, pages = {110136}, doi = {10.1016/j.ijfoodmicro.2023.110136}, pmid = {36807004}, issn = {1879-3460}, abstract = {Listeria monocytogenes is a facultatively intracellular pathogenic bacterium that can provoke invasive listeriosis, a severe foodborne infection in humans. Outside the host, this is capable to survive for long periods in soil, and water, as well as on plants, while, like many other microorganisms, this can also attach to abiotic surfaces, such as food contact ones, forming biofilms on them. It has been suggested that inside those sessile communities, L. monocytogenes cells not only display an increased stress tolerance but may also boost their pathogenicity. In this work, the expression of ten key stress response and/or virulence-related genes (i.e., groEL, hly, iap, inlA, inlB, lisK, mdrD, mdrL, prfA, and sigB) was studied in three different L. monocytogenes strains (AAL20066, AAL20107, and PL24), all isolated from foods and each belonging to a different listeriosis-associated serovar (1/2a, 1/2b, and 1/2c, respectively). For this, each strain was initially left to develop a mature biofilm on a model polystyrene surface (Petri dish) by incubating for 144 h (6 days) at 20 °C in tryptone soya broth (with medium renewal every 48 h). Following incubation, both biofilm and the surrounding free-swimming (planktonic) cells were recovered, and their gene expressions were comparatively evaluated through targeted reverse transcription-quantitative polymerase chain reactions (RT-qPCR). Results revealed a strain-dependent differential gene expression between the two cell types. Thus, for instance, in strain AAL20107 (ser. 1/2b) biofilm growth worryingly resulted in a significant overexpression of all the studied genes (P < 0.05), whereas in strain PL24 (ser. 1/2c), the expression of most genes (8/10) did not change upon biofilm growth, with only two of them (groEL and hly) being again significantly upregulated. Such transcriptomic strain variability in stress adaptation and/or virulence induction should be generally considered in the physiological studies of pathogenic biofilms and preferably upon designing and implementing novel and more efficient eradication methods.}, }
@article {pmid36806829, year = {2023}, author = {Amorim, CF and Iglesias, BA and Pinheiro, TR and Lacerda, LE and Sokolonski, AR and Pedreira, BO and Moreira, KS and Burgo, TAL and Meyer, R and Azevedo, V and Portela, RW}, title = {Photoinactivation of different Candida species and inhibition of biofilm formation induced by water-soluble porphyrins.}, journal = {Photodiagnosis and photodynamic therapy}, volume = {}, number = {}, pages = {103343}, doi = {10.1016/j.pdpdt.2023.103343}, pmid = {36806829}, issn = {1873-1597}, abstract = {BACKGROUND: Candida spp. is the main fungal genus related to infections in humans, and its treatment has become a challenge due to the production of biofilm and its resistance/multi-resistance profile to conventional antifungals. Antimicrobial photodynamic therapy stands out as a treatment characterized by a broad spectrum of antimicrobial action, being able to induce oxidative stress in pathogens, and porphyrins are photosensitizers with high selectivity to pathogens. Thus, this work aimed to analyze the photoinactivation of different species of Candida by two cationic (4-H2TMeP[+] and 3-H2TMeP[+]) and one anionic (4-H2TPSP[‒]) porphyrins.<br><br>MATERIALS AND METHODS: Microdilution assays were performed to determine the MIC100, with subsequent determination of MFC100. Determination of oxidative species was done through the use of scavengers, while biofilm morphological features were investigated using the atomic force microscopy.<br><br>RESULTS: Cationic porphyrins were significantly efficient in inactivating Candida albicans and non-albicans species with 100% growth inhibition and fungicidal activity (MFC100/MIC100 &#x2264; 4.0). The cationic porphyrins were also able to interfere in Candida spp biofilm formation. The photo-oxidative mechanism activated by 3-H2TMeP[+] in Candida spp. is concurrent with the production of singlet oxygen and oxygen radical species. In the AFM analysis, 3-H2TMeP[+] was able to reduce yeast adhesion to the surface.<br><br>CONCLUSIONS: Cationic porphyrins can photo-inactivate different species of Candida in both planktonic and biofilm-associated forms, and reduce the adhesion of these fungi to the surface.}, }
@article {pmid36806045, year = {2023}, author = {Vetrivel, A and Vetrivel, P and Dhandapani, K and Natchimuthu, S and Ramasamy, M and Madheswaran, S and Murugesan, R}, title = {Inhibition of biofilm formation, quorum sensing and virulence factor production in Pseudomonas aeruginosa PAO1 by selected LasR inhibitors.}, journal = {International microbiology : the official journal of the Spanish Society for Microbiology}, volume = {}, number = {}, pages = {}, pmid = {36806045}, issn = {1618-1905}, abstract = {The quorum sensing network of Pseudomonas aeruginosa mediates the regulation of genes controlling biofilm formation and virulence factors. The rise of drug resistance to Pseudomonas aeruginosa infections has made quorum sensing-regulated biofilm formation in clinical settings a major issue. In the present study, LasR inhibitors identified in our previous study were evaluated for their antibiofilm and antiquorum sensing activities against P. aeruginosa PAO1. The compounds selected were (3-[2-(3,4-dimethoxyphenyl)-2-(1H-indol-3-yl)ethyl]-1-(2-fluorophenyl)urea) (C1), (3-(4-fluorophenyl)-2-[(3-methylquinoxalin-2-yl)methylsulfanyl]quinazolin-4-one) (C2) and (2-({4-[4-(2-methoxyphenyl)piperazin-1-yl]pyrimidin-2-yl}sulfanyl)-N-(2,4,6-trimethylphenyl)acetamide) (C3). The minimum inhibitory concentrations of C1 and C2 were 1000 μM, whereas that of C3 was 500 μM. At sub-MICs, the compounds showed potent antibiofilm activity without affecting the growth of P. aeruginosa PAO1. Electron microscopy confirmed the disruption of biofilm by the selected compounds. The antiquorum sensing activity of the compounds was revealed by the inhibition of violacein in Chromobacterium violaceum and the inhibition of swimming and swarming motilities in P. aeruginosa PAO1. Furthermore, the compounds also attenuated the production of quorum sensing-mediated virulence factors. The qRT-PCR revealed the downregulation of quorum sensing regulatory genes, namely lasI, lasR, rhlI, rhlR, lasB, pqsA and pqsR. The selected compounds also exhibited lower cytotoxicity against peripheral blood lymphocytes. Thus, this study could pave a way to explore these compounds for the development of therapeutic agent against Pseudomonas aeruginosa biofilm-related infections.}, }
@article {pmid36805382, year = {2023}, author = {Jones, SU and Chew, CH and Yeo, CC and Abdullah, FH and Othman, N and Kee, BP and Chua, KH and Puah, SM}, title = {The phenotypes and genotypes associated with biofilm formation among methicillin-susceptible Staphylococcus aureus (MSSA) isolates collected from a tertiary hospital in Terengganu, Malaysia.}, journal = {International microbiology : the official journal of the Spanish Society for Microbiology}, volume = {}, number = {}, pages = {}, pmid = {36805382}, issn = {1618-1905}, abstract = {Methicillin-susceptible Staphylococcus aureus (MSSA) is an important nosocomial pathogen worldwide. This study aims to investigate the in vitro biofilm-forming ability of clinical MSSA isolated from various sources in the main public tertiary referral hospital in Terengganu, Malaysia and to detect the presence of biofilm-associated and regulatory genes among these isolates. A total of 104 MSSA isolates [pus (n = 75), blood (n = 24), respiratory secretions (n = 2), eye (n = 2), and urine (n = 1)] were investigated for slime production and biofilm formation using Congo red agar and crystal violet microtitre plate, respectively. Fifteen MSSA isolates with varying degrees of biofilm formation were selected for validation via a real-time cell analyser. All isolates were screened for microbial surface components recognising adhesive matrix molecules (MSCRAMM) and accessory gene regulator (agr) using polymerase chain reaction assay. A total of 76.0% (79/104) isolates produced slime layer, while all isolates developed biofilm as follows: 52.8% (55/104) strong biofilm producers, 40.4% (42/104) intermediate biofilm producers, and 6.7% (7/104) weak biofilm producers. A total of 98.1% (102/104) isolates carried at least one of the screened MSCRAMM gene(s) with the eno gene detected at the highest rate (87.5%, 91/104), while the sasG gene was significantly associated with strong biofilm production (p = 0.015). Three agr groups, 1, 2, and 3, were detected among the MSSA isolates with a predominance of agr-3 (32.7%, 34/104). In conclusion, biofilm formation varied greatly among clinical MSSA isolates, and the presence of sasG gene and agr-1 may play important role in initiating MSSA infections via biofilm formation.}, }
@article {pmid36801575, year = {2023}, author = {Cai, W and Cai, L and Zhao, J and Yao, H}, title = {Prokaryotic community interchange between distinct microhabitats causes community pressure on anammox biofilm development.}, journal = {Water research}, volume = {233}, number = {}, pages = {119726}, doi = {10.1016/j.watres.2023.119726}, pmid = {36801575}, issn = {1879-2448}, abstract = {Biofilms are an efficient way to underpin the biological process of wastewater treatment. However, little is known about the driving forces of biofilm formation and development in industrial settings. Long-term observation of anammox biofilms indicated the interplay between different microhabitats (biofilm, aggregate, plankton) was important in sustaining biofilm formation. SourceTracker analysis showed that 88.77 ± 2.26% of initial biofilm originated from the aggregate, however, independent evolution was led by anammox species in the later stage (182d and 245d). Noticeably, the source proportion of aggregate and plankton increased when temperature varied, suggesting an interchange of species between different microhabitats could be helpful to biofilm recovery. The microbial interaction pattern and community variation displayed similar trends, but the unknown source proportion of interaction was very high during the entire incubation (7-245d), thereby the same species may develop different relationships within the distinct microhabitats. The core phyla, Proteobacteria and Bacteroidota, accounted for ∼80% of interactions in all lifestyles, which is consistent with the fact that Bacteroidota played important role in the early stage of biofilm assembly. Although anammox species evolved few links with other OTUs, Candidatus Brocadiaceae still outcompeted the NS9 marine group to dominate the homogeneous selection process in the later stage (56-245d) of biofilm assembly, implying that the functional species may be decoupled from the core species in the microbial network. The conclusions will shed a light on the understanding of biofilm development in large-scale biosystems of wastewater treatment.}, }
@article {pmid36800842, year = {2022}, author = {Hassan, PA and Hameed Saeed, C and Rashid, SA and Sorchee, SM and Shareef, SH}, title = {Identification of Streptococcus sanguinis genes producing biofilm from gingivitis.}, journal = {Cellular and molecular biology (Noisy-le-Grand, France)}, volume = {68}, number = {8}, pages = {34-40}, doi = {10.14715/cmb/2022.68.8.6}, pmid = {36800842}, issn = {1165-158X}, abstract = {Streptococcus sanguinis is a teeth commensal frontier colonizer and among the most common species in the oral biofilm. Dental plaque, caries, and gingivitis/periodontitis are caused by dysbiosis of oral flora. A biofilm assay was developed to investigate biofilm formation in S. sanguinis using the microtiter plate, tube, and Congo red agar methods in order to identify causing bacteria and determine responsible genes. Three genes, including pur B, thr B, and pyre E, were suspected of playing a role in forming in vivo biofilms in S. sanguinis. The present study shows these genes to be responsible for increased biofilm formation in gingivitis patients.}, }
@article {pmid36800793, year = {2023}, author = {Seredin, PV and Ippolitov, YA and Goloshchapov, DL and Kashkarov, VM and Ippolitov, IY and Solaiman, MA}, title = {[Distinctions in molecular composition of the dental biofilm depending on the method of exo-/endogeneous caries prevention and cariogenic condition of a patient].}, journal = {Stomatologiia}, volume = {102}, number = {1}, pages = {86-93}, doi = {10.17116/stomat202310201186}, pmid = {36800793}, issn = {0039-1735}, mesh = {Humans ; *Dental Caries Susceptibility ; Australia ; *Dental Caries/prevention &amp; control ; Biofilms ; Phosphates ; Lipids ; }, abstract = {PURPOSE OF THE STUDY: For the first time distinctions of molecular composition of the dental biofilm at the stages of exo- and endogeneous caries prevention were studied for persons with different cariogenic conditions involving synchrotron molecular spectroscopy techniques.<br><br>MATERIAL AND METHODS: The samples of the dental biofilm collected from participants of the research were studied at the different stages of experiment. The studies of molecular composition of the biofilms were employed involving the equipment set in the Infrared Microspectroscopy (IRM) laboratory of Australian synchrotron.<br><br>RESULTS: Basing on the data obtained by synchrotron infrared spectroscopy with Fourier transform as well as using the calculations of the ratios between organic and mineral components and also statistical analysis of the data we could estimate the changes proceeding in the molecular composition of dental biofilm in a dependence of homeostasis conditions in the oral cavity at the stages of exo- and endogeneous caries prevention.<br><br>CONCLUSION: Observed changes in the values of phosphate/protein/lipid, phosphate/mineral and phospholipid/lipid ratios as well as the presence of statistically significant intra- and intergroup in these coefficients mean that mechanisms of adsorption for the ions, compounds and molecular complexes incoming from the oral fluid into the dental biofilm at the stage of exo-/endogeneous caries prevention are different for the patients in normal condition and for those ones with the developing caries.}, }
@article {pmid36799228, year = {2023}, author = {Hagstrand Aldman, M and Thompson, O and Påhlman, LI}, title = {Biofilm formation is associated with poor outcome in prosthetic joint infections caused by Staphylococcus lugdunensis.}, journal = {Infectious diseases (London, England)}, volume = {}, number = {}, pages = {1-5}, doi = {10.1080/23744235.2023.2180534}, pmid = {36799228}, issn = {2374-4243}, abstract = {BACKGROUND: Staphylococcus lugdunensis has been described as a pathogen of increasing importance in prosthetic joint infections (PJI). Our aim was to describe the clinical presentation of PJI caused by S. lugdunensis, and to correlate the biofilm-forming ability of the bacterial isolates to clinical outcome.<br><br>METHOD: S. lugdunensis isolates from PJI episodes during 2015-2019 were included and analysed for biofilm formation using a microtiter plate assay. Medical records from the corresponding patients were reviewed.<br><br>RESULTS: We identified 36 patients with PJI caused by S. lugdunensis during the study period. Early postoperative PJIs were most frequent (n&#x2009;=&#x2009;20, 56%). Surgical intervention was performed in a majority of the patients (n&#x2009;=&#x2009;33, 92%), and the dominating type of antibiotic treatment was a combination of rifampicin and ciprofloxacin (n&#x2009;=&#x2009;27, 75%). The treatment success-rate was 81% (n&#x2009;=&#x2009;29). All isolates causing PJI were able to form biofilm in&#xa0;vitro. Biofilm formation was significantly stronger in isolates causing relapsing vs non-relapsing PJI (mean OD550 3.1&#x2009;&#xb1;&#x2009;0.23 vs 1.14&#x2009;&#xb1;&#x2009;0.73 p&#x2009;=&#x2009;.001) and strong biofilm formation was also associated with late acute hematogenic PJI (mean OD550 1.8&#x2009;&#xb1;&#x2009;0.93 vs. 0.93&#x2009;&#xb1;&#x2009;0.81, p&#x2009;=&#x2009;.01).<br><br>CONCLUSION: Strong biofilm production in S. lugdunensis isolates was associated with relapse in PJI.}, }
@article {pmid36798165, year = {2023}, author = {Razgaleh, SA and Wrench, A and Jones, AD}, title = {Surface Energy and Viscoelastic Characteristics of Staphylococcus epidermidis and Cutibacterium acnes Biofilm on Commercial Skin Constructs versus Agar.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.02.10.527933}, pmid = {36798165}, abstract = {Biofilms are recalcitrant to both study and infectious disease treatment as it requires not only the study or management of single organism behavior, but also many dynamical interactions including but not limited to bacteria-bacteria, bacteria-host, bacteria-nutrients, and bacteria-material across multiple time scales. This study performs comparative and quantitative research of two materials used in biofilm research, TSA agar and skin epidermal, to reveal how adhesion effects viscoelastic properties of biofilms at long time scales. We show that the host surface stressors, such as wettability and surface energy, impact the biofilm's mechanical integrity and viscoelastic properties. While it is known that the bacteria-material interface influences initial biofilm formation and external stress influences mature biofilm function, this study examines the influence of the bacteria-material interface on mature biofilms. These mechanical viscoelastic properties have the potential to determine metabolite and pathogenesis pathways which means that the platform researchers use to study impacts the outcome.}, }
@article {pmid36797306, year = {2023}, author = {Lai, SJ and Tu, IF and Tseng, TS and Tsai, YH and Wu, SH}, title = {The deficiency of poly-β-1,6-N-acetyl-glucosamine deacetylase trigger A. baumannii to convert to biofilm-independent colistin-tolerant cells.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {2800}, pmid = {36797306}, issn = {2045-2322}, mesh = {*Colistin/pharmacology/metabolism ; Glucosamine/metabolism ; Anti-Bacterial Agents/pharmacology/metabolism ; Biofilms ; *Acinetobacter baumannii ; Microbial Sensitivity Tests ; Drug Resistance, Multiple, Bacterial ; }, abstract = {Acinetobacter baumannii is a nosocomial pathogen that can be resistant to antibiotics by rapidly modulating its anti-drug mechanisms. The multidrug-resistant A. baumannii has been considered one of the most threatening pathogens to our society. Biofilm formation and persistent cells within the biofilm matrix are recognized as intractable problems, especially in hospital-acquired infections. Poly-β-1,6-N-acetyl-glucosamine (PNAG) is one of the important building blocks in A. baumannii's biofilm. Here, we discover a protein phosphoryl-regulation on PNAG deacetylase, AbPgaB1, in which residue Ser411 was phosphorylated. The phosphoryl-regulation on AbPgaB1 modulates the product turnover rate in which deacetylated PNAG is produced and reflected in biofilm production. We further uncovered the PgaB deficient A. baumannii strain shows the lowest level of biofilm production but has a high minimal inhibition concentration to antibiotic colistin and tetracycline. Based on bactericidal post-antibiotic effects and time-dependent killing assays with antibacterial drugs, we claim that the PgaB-deficient A. baumannii converts to colistin-tolerant cells. This study utilizes a biofilm-independent colistin-tolerant model of A. baumannii to further investigate its characteristics and mechanisms to better understand clinical outcomes.}, }
@article {pmid36796467, year = {2023}, author = {You, J and Park, J and Choi, D and Yun, J and Choi, H and Lee, IH}, title = {Implant-associated biofilm infection established in an experimental Galleria mellonella model.}, journal = {Developmental and comparative immunology}, volume = {}, number = {}, pages = {104670}, doi = {10.1016/j.dci.2023.104670}, pmid = {36796467}, issn = {1879-0089}, abstract = {The study reports in vivo biofilm infection implemented in an insect model. We mimicked implant-associated biofilm infections in Galleria mellonella larvae using toothbrush bristles and methicillin-resistant Staphylococcus aureus (MRSA). In vivo biofilm formation on bristle was achieved by sequentially injecting a bristle and MRSA into the larval hemocoel. It was found that biofilm formation was in progress without any external sign of infection in most of the bristle-bearing larvae for 12 h after MRSA inoculation. Whereas the activation of the prophenoloxidase system did not affect the preformed in vitro MRSA biofilms, an antimicrobial peptide interfered with in vivo biofilm formation when injected into bristle-bearing larvae infected with MRSA. Finally, our confocal laser scanning microscopic analysis revealed that the biomass of the in vivo biofilm is greater compared to that of the in vitro biofilm and harbors a distribution of dead cells, which might be bacteria and/or host cells.}, }
@article {pmid36793505, year = {2023}, author = {Fowler, SJ and Torresi, E and Dechesne, A and Smets, BF}, title = {Biofilm thickness controls the relative importance of stochastic and deterministic processes in microbial community assembly in moving bed biofilm reactors.}, journal = {Interface focus}, volume = {13}, number = {2}, pages = {20220069}, pmid = {36793505}, issn = {2042-8898}, abstract = {Deterministic and stochastic processes are believed to play a combined role in microbial community assembly, though little is known about the factors determining their relative importance. We investigated the effect of biofilm thickness on community assembly in nitrifying moving bed biofilm reactors using biofilm carriers where maximum biofilm thickness is controlled. We examined the contribution of stochastic and deterministic processes to biofilm assembly in a steady state system using neutral community modelling and community diversity analysis with a null-modelling approach. Our results indicate that the formation of biofilms results in habitat filtration, causing selection for phylogenetically closely related community members, resulting in a substantial enrichment of Nitrospira spp. in the biofilm communities. Stochastic assembly processes were more prevalent in biofilms of 200 µm and thicker, while stronger selection in thinner (50 µm) biofilms could be driven by hydrodynamic and shear forces at the biofilm surface. Thicker biofilms exhibited greater phylogenetic beta-diversity, which may be driven by a variable selection regime caused by variation in environmental conditions between replicate carrier communities, or by drift combined with low migration rates resulting in stochastic historical contingency during community establishment. Our results indicate that assembly processes vary with biofilm thickness, contributing to our understanding of biofilm ecology and potentially paving the way towards strategies for microbial community management in biofilm systems.}, }
@article {pmid36792064, year = {2023}, author = {Kao, S and Serfecz, J and Sudhakar, A and Likosky, K and Romiyo, V and Tursi, S and Tükel, &#xc7; and Wilson, JW}, title = {Salmonella enterica serovar Typhimurium STM1266 encodes a regulator of curli biofilm formation: the brfS gene.}, journal = {FEMS microbiology letters}, volume = {}, number = {}, pages = {}, doi = {10.1093/femsle/fnad012}, pmid = {36792064}, issn = {1574-6968}, abstract = {The major biofilm pathway in Salmonella enterica serovar Typhimurium involves specific growth conditions that induce the csgA gene whose product forms surface curli fibers that mediate biofilm formation. We have found that the previously uncharacterized STM1266 gene in S. Typhimurium plays a role in regulating biofilm formation via the curli pathway. S. Typhimurium ΔSTM1266 strains display a biofilm defect, and overexpression of STM1266 results in enhanced biofilm formation. STM1266 deletion resulted in lowered csgA expression using promoter-reporter β-galactosidase assays, and csgA and csgD deletions abrogate the effects of STM1266 overexpression on biofilm formation while deletion of bcsA (encoding an essential enzyme for cellulose formation) has no effect. In a mouse infection model, the ΔSTM1266 strain displayed results similar to those seen for previously-reported ΔcsgA strains. The STM1266 gene is predicted to encode a DNA-binding transcriptional regulator of the MerR family and is homologous to the E. coli BluR regulator protein. We respectfully propose to ascribe the name brfS (biofilm regulator for Salmonella Typhimurium) to the STM1266 gene.}, }
@article {pmid36791856, year = {2023}, author = {Chen, S and Haga, M and Imai, I and Sakai, R and Fujita, MJ}, title = {Function of the algicidal bacterium Pseudomonas sp. Go58 isolated from the biofilm on a water plant, and its active compounds, pyoluteorins.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {162088}, doi = {10.1016/j.scitotenv.2023.162088}, pmid = {36791856}, issn = {1879-1026}, abstract = {In the development of applications to mitigate nuisance cyanobacterial blooms, environmentally friendly approaches have gained much attention. Recently, we found a bacterial strain Go58, which was isolated from the biofilm of a water plant, that showed potent algicidal activity against the bloom-forming cyanobacterium Microcystis aeruginosa. Whole genome sequencing of strain Go58 suggested that it is potentially a novel species closely related to Pseudomonas protegens. Pyoluteorins were obtained from the culture broth of this strain, and they demonstrated high toxicity against cultured cyanobacterial species, including M. aeruginosa and Anabaena cylindrica, but less toxicity against eukaryotic microalgae and other aquatic organisms. The production of pyoluteorin was enhanced by the presence of the target cyanobacterium. When a wild-caught microalgal consortium was treated with either strain Go58 or pyoluteorin, both efficiently suppressed the growth of harmful wild cyanobacteria, but promoted the growth of some specific eukaryotic microalgae. Since P. protegens is globally ubiquitous and highly anticipated to be a biopesticide for infectious diseases in the field of agriculture, the similar bacterial group identified in this study may also have potential as a safe on-site collectable biological countermeasure for controlling cyanobacterial blooms.}, }
@article {pmid36791517, year = {2023}, author = {Zarei, M and Rahimi, S and Fazlara, A and Anvari, SE}, title = {High biofilm-forming Pseudomonas strains isolated from poultry slaughterhouse surfaces: Their importance in the persistence of Salmonella enteritidis in slaughterhouses.}, journal = {International journal of food microbiology}, volume = {390}, number = {}, pages = {110126}, doi = {10.1016/j.ijfoodmicro.2023.110126}, pmid = {36791517}, issn = {1879-3460}, abstract = {The surfaces of poultry slaughterhouse equipment are significant sources of contamination with Pseudomonas strains, which leads to spoilage of poultry meat during subsequent refrigerated storage. In this study, Pseudomonas strains with high biofilm-forming ability were isolated from different surfaces of the poultry slaughterhouse equipment, identified based on molecular data, and characterized their biofilm-forming ability. After 24 h of incubation at 25 °C, 54 out of 58 Pseudomonas strains produced biofilm in vitro on polystyrene microplates. Seven isolates with high-ability to produce biofilm were identified as P. fragi (three strains), P. fluorescens (two strains), P. lundensis and P. cedrina. Despite their differences, these strains produced high amounts of biofilm in pure- and dual-species cultures with S. enteritidis on stainless steel surfaces. However, their ability to produce dual-species biofilms with S. enteritidis depends on whether S. enteritidis form the biofilm simultaneously with the Pseudomonas strains or whether Pseudomonas strains have already formed a biofilm. In concurrent inoculation, S. enteritidis participated in biofilm formation with all seven Pseudomonas strains with varying percent contributions. However, in delayed inoculation, S. enteritidis did not contribute in the biofilm formed by P. lundensis R26, P. fragi R39, and P. fluorescens R47. In addition to highlighting the complexity of bacterial interactions associated with Pseudomonas strains, these results showed that Pseudomonas strains can be implicated in Salmonella persistence in poultry slaughterhouses.}, }
@article {pmid36787160, year = {2023}, author = {Peerzada, Z and Shah, MD and Kharkar, PS and Desai, KB}, title = {Exploration of the inhibitory effect of Cassia fistula on quorum sensing mediated virulence factor production and biofilm activity in Pseudomonas aeruginosa: an in vivo study in model organism Caenorhabditis elegans.}, journal = {Journal of medical microbiology}, volume = {72}, number = {2}, pages = {}, doi = {10.1099/jmm.0.001578}, pmid = {36787160}, issn = {1473-5644}, abstract = {Introduction. Resistance to antibiotics is leading to challenges in the treatment of microbial diseases. One amongst the various approaches to control these pathogens is quorum sensing (QS), which is used to rectify resistance issues. Blocking the bacterial QS circuit is the most reliable anti-virulence therapy to control pathogenicity-associated genes. Pseudomonas aeruginosa is a contagious bacterium that proliferates in the host by using signalling molecules like acyl-homoserine lactones; these molecules generate and disseminate toxins and virulence factors for increasing host infection.Hypothesis. The herb Cassia fistula is known to have antimicrobial, antidiabetic, anti-inflammatory, antitumor medicinal properties amongst others. We hypothesize that its crude extracts will inhibit the QS circuit of Pseudomonas aeruginosa (P. aeruginosa).Aim. The research work was aimed at evaluating anti-quorum sensing and anti-biofilm activity of various crude extracts from Cassia fistula against P. aeruginosa.Methodology. Various extraction methods and solvents were availed for maximum separation, and the extracts were screened for anti-quorum sensing activity. The most potent Fruit Ethyl acetate (FEE) extract at non-inhibitory concentrations was found to interrupt both short-chain (RhlI/R) and long-chain (LasI/R) QS circuits and other virulence factors (P<0.05) such as elastase, protease, rhamnolipids and pyocyanin levels in P. aeruginosa. Biofilm inhibitory properties of FEE were demonstrated using atomic force microscopy, scanning electron microscope and confocal laser microscope. Caenorhabditis elegans infection model (Paralytic assay) was developed to determine the protective role of FEE by reducing the pathogenicity of P. aeruginosa.Results. The study results suggest that hot crude FEE extract interfered in the QS circuit, leading to comprehensive debilitation of QS-controlled virulence factors. The extract reduced virulence factor production in P. aeruginosa at 4 mg ml[-1] concentration whilst paradoxically promoting biofilm formation. Possibly, higher sugar content in the extract promoted clump formation of biofilm architecture by increasing exopolysaccharide production. Moreover, in vivo analysis of bacterial pathogenesis on Caenorhabditis elegans reveals a drastic increase in survival rates in FEE treated worms compared to untreated control.Conclusions. FEE showed promising QS inhibitory activity against P. aeruginosa. In the future, additional purification of crude FEE is required to remove carbohydrates, and pure isolated phytochemicals from FEE could be used as therapeutic agents to control QS-mediated infections in P. aeruginosa.}, }
@article {pmid36786593, year = {2023}, author = {Chen, Z and Zarazúa-Osorio, B and Srivastava, P and Fujita, M and Igoshin, OA}, title = {The Slowdown of Growth Rate Controls the Single-Cell Distribution of Biofilm Matrix Production via an SinI-SinR-SlrR Network.}, journal = {mSystems}, volume = {}, number = {}, pages = {e0062222}, doi = {10.1128/msystems.00622-22}, pmid = {36786593}, issn = {2379-5077}, abstract = {In Bacillus subtilis, master regulator Spo0A controls several cell-differentiation pathways. Under moderate starvation, phosphorylated Spo0A (Spo0A~P) induces biofilm formation by indirectly activating genes controlling matrix production in a subpopulation of cells via an SinI-SinR-SlrR network. Under severe starvation, Spo0A~P induces sporulation by directly and indirectly regulating sporulation gene expression. However, what determines the heterogeneity of individual cell fates is not fully understood. In particular, it is still unclear why, despite being controlled by a single master regulator, biofilm matrix production and sporulation seem mutually exclusive on a single-cell level. In this work, with mathematical modeling, we showed that the fluctuations in the growth rate and the intrinsic noise amplified by the bistability in the SinI-SinR-SlrR network could explain the single-cell distribution of matrix production. Moreover, we predicted an incoherent feed-forward loop; the decrease in the cellular growth rate first activates matrix production by increasing in Spo0A phosphorylation level but then represses it via changing the relative concentrations of SinR and SlrR. Experimental data provide evidence to support model predictions. In particular, we demonstrate how the degree to which matrix production and sporulation appear mutually exclusive is affected by genetic perturbations. IMPORTANCE The mechanisms of cell-fate decisions are fundamental to our understanding of multicellular organisms and bacterial communities. However, even for the best-studied model systems we still lack a complete picture of how phenotypic heterogeneity of genetically identical cells is controlled. Here, using B. subtilis as a model system, we employ a combination of mathematical modeling and experiments to explain the population-level dynamics and single-cell level heterogeneity of matrix gene expression. The results demonstrate how the two cell fates, biofilm matrix production and sporulation, can appear mutually exclusive without explicitly inhibiting one another. Such a mechanism could be used in a wide range of other biological systems.}, }
@article {pmid36786569, year = {2023}, author = {Cont, A and Vermeil, J and Persat, A}, title = {Material Substrate Physical Properties Control Pseudomonas aeruginosa Biofilm Architecture.}, journal = {mBio}, volume = {}, number = {}, pages = {e0351822}, doi = {10.1128/mbio.03518-22}, pmid = {36786569}, issn = {2150-7511}, abstract = {In the wild, bacteria are most frequently found in the form of multicellular structures called biofilms. Biofilms grow at the surface of abiotic and living materials with wide-ranging mechanical properties. The opportunistic pathogen Pseudomonas aeruginosa forms biofilms on indwelling medical devices and on soft tissues, including burn wounds and the airway mucosa. Despite the critical role of substrates in the foundation of biofilms, we still lack a clear understanding of how material mechanics regulate their architecture and the physiology of resident bacteria. Here, we demonstrate that physical properties of hydrogel material substrates define P. aeruginosa biofilm architecture. We show that hydrogel mesh size regulates twitching motility, a surface exploration mechanism priming biofilms, ultimately controlling the organization of single cells in the multicellular community. The resulting architectural transitions increase P. aeruginosa's tolerance to colistin, a last-resort antibiotic. In addition, mechanical regulation of twitching motility affects P. aeruginosa clonal lineages, so that biofilms are more mixed on relatively denser materials. Our results thereby establish material properties as a factor that dramatically affects biofilm architecture, antibiotic efficacy, and evolution of the resident population. IMPORTANCE The biofilm lifestyle is the most widespread survival strategy in the bacterial world. Pseudomonas aeruginosa biofilms cause chronic infections and are highly recalcitrant to antimicrobials. The genetic requirements allowing P. aeruginosa to grow into biofilms are known, but not the physical stimuli that regulate their formation. Despite colonizing biological tissues, investigations of biofilms on soft materials are limited. In this work, we show that biofilms take unexpected forms when growing on soft substrates. The physical properties of the material shape P. aeruginosa biofilms by regulating surface-specific twitching motility. Physical control of biofilm morphogenesis ultimately influences the resilience of biofilms to antimicrobials, linking physical environment with tolerance to treatment. Altogether, our work established that the physical properties of a surface are a critical environmental regulator of biofilm biogenesis and evolution.}, }
@article {pmid36784787, year = {2023}, author = {Chou, TKT and Lee, DD and Chiou, JG and Galera-Laporta, L and Ly, S and Garcia-Ojalvo, J and Suel, GM}, title = {A clock and wavefront mechanism organizes cell types in a bacterial biofilm.}, journal = {Biophysical journal}, volume = {122}, number = {3S1}, pages = {538a-539a}, doi = {10.1016/j.bpj.2022.11.2853}, pmid = {36784787}, issn = {1542-0086}, }
@article {pmid36784106, year = {2023}, author = {Chou, KT and Lee, DD and Chiou, JG and Galera-Laporta, L and Ly, S and Garcia-Ojalvo, J and Suel, GM}, title = {A segmentation clock patterns cellular differentiation in a bacterial biofilm.}, journal = {Biophysical journal}, volume = {122}, number = {3S1}, pages = {412a}, doi = {10.1016/j.bpj.2022.11.2241}, pmid = {36784106}, issn = {1542-0086}, }
@article {pmid36783876, year = {2023}, author = {Gomes, PS and Dos Reis Melo, MC and Gomes, DEB and Bernardi, RC}, title = {Molecular mechanisms of biofilm formation in Staphylococci bacteria: How antibiotic resistant bacteria is evolving to become more resilient to mechanical force loads.}, journal = {Biophysical journal}, volume = {122}, number = {3S1}, pages = {36a}, doi = {10.1016/j.bpj.2022.11.409}, pmid = {36783876}, issn = {1542-0086}, }
@article {pmid36781489, year = {2023}, author = {Çam, S and Bicek, S}, title = {The effects of temperature, salt, and phosphate on biofilm and exopolysaccharide production by Azotobacter spp.}, journal = {Archives of microbiology}, volume = {205}, number = {3}, pages = {87}, pmid = {36781489}, issn = {1432-072X}, abstract = {Inoculation of agriculturally important biofilms to plants under stress conditions has been of great interest in recent years. Therefore, in this study, biofilm- and exopolysaccharide (EPS)-forming ability of Azotobacter spp. was examined under different temperatures, NaCl concentrations, and phosphate levels. Azotobacter strains formed varying levels of biofilm and EPS depending on the tested factors. The pattern of biofilm formation was similar to that of EPS production under the conditions tested. Biofilm and EPS production at 28 °C was consistently higher than at either 18 or 37 °C. Biofilm production significantly increased in A. chroococcum strains (SBS2, SBS4, and SBS12) and A. vinelandii SBS6 with increasing salinity. Furthermore, a strong negative correlation was observed between biofilm or EPS production and increasing phosphate concentrations. Higher phosphate concentrations decreased biofilm and EPS production. In conclusion, contrary to temperature and phosphate effect, salinity differently affected biofilm and EPS production by Azotobacter strains.}, }
@article {pmid36780700, year = {2023}, author = {Sharma, K and Pandey, S and Sekar, H and Alan, T and Gundabala, V}, title = {Microfluidics Based Generation of Curcumin Loaded Microfibrous Mat against Staphylococcus aureus Biofilm by Photodynamic Therapy.}, journal = {ACS applied bio materials}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsabm.2c00971}, pmid = {36780700}, issn = {2576-6422}, abstract = {The rapid increase in multidrug resistant biofilm infections is a major concern for global health. A highly effective therapy is required for the treatment of biofilm related infections. In this study, curcumin loaded alginate microfibers were generated by using the microfluidic technique. In this strategy, alginate microfibers are used as a carrier for the encapsulation of curcumin and then are irradiated with blue light to assess the efficacy of a combined therapy (blue light + curcumin) against drug resistant Staphylococcus aureus (S. aureus). The advantage of utilizing photodynamic therapy (PDT) is the usage of a non-antibiotic mode to inactivate bacterial cells. In the presence of blue light, the curcumin loaded alginate microfibers have shown good eradication activity against biofilms formed by multidrug resistant S. aureus. We achieved different diameters of curcumin loaded alginate microfibers through manipulation of flow rates. The curcumin loaded microfibers were characterized for their size, morphology, and curcumin encapsulation. Further, the efficacy of these microfibers in the presence of blue light has been evaluated against biofilm forming S. aureus (NCIM 5718) through optical and electron microscopy. This study employs microfluidic techniques to obtain an efficacious and cost-effective microfibrous scaffold for controlled release of curcumin to treat biofilms in the presence of blue light.}, }
@article {pmid36779942, year = {2023}, author = {Song, L and Yang, H and Meng, X and Su, R and Cheng, S and Wang, H and Bai, X and Guo, D and Lü, X and Xia, X and Shi, C}, title = {Inhibitory Effects of Trans-Cinnamaldehyde Against Pseudomonas aeruginosa Biofilm Formation.}, journal = {Foodborne pathogens and disease}, volume = {20}, number = {2}, pages = {47-58}, doi = {10.1089/fpd.2022.0073}, pmid = {36779942}, issn = {1556-7125}, abstract = {Pseudomonas aeruginosa biofilm formation has been considered to be an important determinant of its pathogenicity in most infections. The antibiofilm activity of trans-cinnamaldehyde (TC) against P. aeruginosa was investigated in this study. Results demonstrated that the minimum inhibitory concentration (MIC) of TC against P. aeruginosa was 0.8 mg/mL, and subinhibitory concentrations (SICs) was 0.2 mg/mL and below. Crystal violet staining showed that TC at 0.05-0.2 mg/mL reduced biofilm biomass in 48 h in a concentration-dependent mode. The formation area of TC-treated biofilms was significantly declined (p < 0.01) on the glass slides observed by light microscopy. Field-emission scanning electron microscopy further demonstrated that TC destroyed the biofilm morphology and structure. Confocal laser scanning microscopic observed the dispersion of biofilms and the reduction of exopolysaccharides after TC treatment stained with concanavalin A (Con-A)-fluorescein isothiocyanate conjugate and Hoechst 33258. Meanwhile, TC caused a significant decrease (p < 0.01) in the component of polysaccharides, proteins, and DNA in extracellular polymeric substance. The swimming and swarming motility and quorum sensing of P. aeruginosa was also found to be significantly inhibited (p < 0.01) by TC at SICs. Furthermore, SICs of TC repressed the several genes transcription associated with biofilm formation as determined by real-time quantitative polymerase chain reaction. Overall, our findings suggest that TC could be applied as natural and safe antibiofilm agent to inhibit the biofilm formation of P. aeruginosa.}, }
@article {pmid36779720, year = {2023}, author = {Sharma, A and Solis, NV and Huang, MY and Lanni, F and Filler, SG and Mitchell, AP}, title = {Hgc1 Independence of Biofilm Hyphae in Candida albicans.}, journal = {mBio}, volume = {}, number = {}, pages = {e0349822}, doi = {10.1128/mbio.03498-22}, pmid = {36779720}, issn = {2150-7511}, abstract = {Biofilm and hypha formation are central to virulence of the fungal pathogen Candida albicans. The G1 cyclin gene HGC1 is required for hypha formation under diverse in vitro and in vivo growth conditions. Hgc1 is required for disseminated infection and is a linchpin in the argument that hyphal morphogenesis itself is required for pathogenicity. We report here that HGC1 is dispensable for hypha formation during biofilm formation both in vitro, under strong inducing conditions, and in vivo, in a mouse oropharyngeal candidiasis model. These findings are validated with two or more C. albicans isolates. Systematic screening of overexpressed cyclin genes indicates that CCN1 and CLN3 can compensate partially for Hgc1 function during biofilm growth. This conclusion is also supported by the severity of the hgc1Δ/Δ ccn1Δ/Δ double mutant biofilm defect. Our results suggest that hypha formation in biofilm is accomplished by combined action of multiple cyclins, not solely by Hgc1. IMPORTANCE The HGC1 gene encodes a cyclin that is required for virulence of the fungal pathogen Candida albicans. It is required to produce the elongated hyphal filaments of free-living planktonic cells that are associated with virulence. Here, we show that HGC1 is not required to produce hyphae in the alternative growth form of a biofilm community. We observe Hgc1-independent hyphae in two infection-relevant situations, biofilm growth in vitro and biofilm-like oropharyngeal infection. Our analysis suggests that hypha formation in the biofilm state reflects combined action of multiple cyclins.}, }
@article {pmid36779719, year = {2023}, author = {Kher, L and Kelley, K and Santoro, D}, title = {Ultrastructural Analysis of Differences in the Growth and Maturation of Staphylococcus pseudintermedius Biofilm on Biotic and Abiotic Surfaces.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0357722}, doi = {10.1128/spectrum.03577-22}, pmid = {36779719}, issn = {2165-0497}, abstract = {Biofilms are extremely complex yet systematic microbial structures. Studies comparing the differences in their growth on living and nonliving surfaces by electron microscopy are limited. Therefore, the purpose of this study was to ultrastructurally investigate the differences in the growth and development of Staphylococcal biofilm on polycarbonate filters and canine skin explants. Using scanning and transmission electron microscopy (SEM and TEM), Staphylococcus pseudintermedius was incubated for 6, 12, 24, 48, and 72 h. It was observed that similar amounts of exopolymeric substance (EPS) were deposited on the biofilm on both surfaces, but the biofilm on the skin explants was primarily flat, whereas the biofilm on the membrane developed a multilayered plateaued look. Microcolony formation was only observed on the membrane filter during the early stages of biofilm development. On the membrane biofilms, EPS was observed to be deposited in a distinctive pattern. EPS deposition on the membrane surface was observed to peak before it declined, but on the explant, a constant increase was observed at all time points. Cell exposure to the environment on both the membrane filters and explants differed depending on the stage of biofilm formation. On both the membranes and the skin explants, there was a perceptible difference between the biofilm growth patterns and speeds. The results of this study suggest that data extrapolated from studies on biofilm bactericidal compounds performed on abiotic surfaces (such as polycarbonate filters) may not be entirely applicable to biofilm growing on biotic surfaces (e.g., skin) due to ultrastructural variations revealed in this study. IMPORTANCE Biofilm has been recognized as an important source of antimicrobial resistance. These sessile microbial colonies tend to attach and grow on every surface, biotic and abiotic, and they account for approximately 80% of chronic and recurrent infections. Biofilms are not all alike; they have different structures and microbial compositions. This high variability allows for differences in the production of exopolymer substances, affecting antimicrobial penetration. No studies have been published that simultaneously compare the structure of biofilms grown on abiotic (in vitro) and biotic (ex vivo) surfaces. To identify treatment alternatives, it is essential to understand the differences between biofilms. The results of the study show how biofilm structures and compositions are dependent on the substrate on which they grow.}, }
@article {pmid36778889, year = {2023}, author = {Sanchez-Alonso, P and Cobos-Justo, E and Avalos-Rangel, MA and López-Reyes, L and Paniagua-Contreras, GL and Vaca-Paniagua, F and Anastacio-Marcelino, E and López-Ochoa, AJ and Pérez Marquez, VM and Negrete-Abascal, E and Vázquez-Cruz, C}, title = {A Maverick-like cluster in the genome of a pathogenic, moderately virulent strain of Gallibacterium anatis, ESV200, a transient biofilm producer.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {1084766}, pmid = {36778889}, issn = {1664-302X}, abstract = {INTRODUCTION: Gallibacterium anatis causes gallibacteriosis in birds. These bacteria produce biofilms and secrete several fimbrial appendages as tools to cause disease in animals. G. anatis strains contain up to three types of fimbriae. Complete genome sequencing is the strategy currently used to determine variations in the gene content of G. anatis, although today only the completely circularized genome of G. anatis UMN179 is available.<br><br>METHODS: The appearance of growth of various strains of G. anatis in liquid culture medium was studied. Biofilm production and how the amount of biofilm was affected by DNase, Proteinase K, and Pronase E enzymes were analyzed. Fimbrial gene expression was performed by protein analysis and qRT-PCR. In an avian model, the pathogenesis generated by the strains G. anatis ESV200 and 12656-12 was investigated. Using bioinformatic tools, the complete genome of G. anatis ESV200 was comparatively studied to search for virulence factors that would help explain the pathogenic behavior of this strain.<br><br>RESULTS AND DISCUSSION: G. anatis ESV200 strain differs from the 12656-12 strain because it produces a biofilm at 20%. G. anatis ESV200 strain express fimbrial genes and produces biofilm but with a different structure than that observed for strain 12656-12. ESV200 and 12656-12 strains are pathogenic for chickens, although the latter is the most virulent. Here, we show that the complete genome of the ESV200 strain is similar to that of the UNM179 strain. However, these strains have evolved with many structural rearrangements; the most striking chromosomal arrangement is a Maverick-like element present in the ESV200 strain.}, }
@article {pmid36775169, year = {2023}, author = {Kim, HS and Ham, SY and Ryoo, HS and Kim, DH and Yun, ET and Park, HD and Park, JH}, title = {Inhibiting bacterial biofilm formation by stimulating c-di-GMP regulation using citrus peel extract from Jeju Island.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {162180}, doi = {10.1016/j.scitotenv.2023.162180}, pmid = {36775169}, issn = {1879-1026}, abstract = {Biofilms consist of single or multiple species of bacteria embedded in extracellular polymeric substances (EPSs), which affect the increase in antibiotic resistance by restricting the transport of antibiotics to the bacterial cells. An alternative approach to treatment with antimicrobial agents is using biofilm inhibitors that regulate biofilm development without inhibiting bacterial growth. In this study, we found that citrus peel extract from Jeju Island (CPEJ) can inhibit bacterial biofilm formation. According to the results, CPEJ concentration-dependently reduced biofilm formation without affecting bacterial growth. Additionally, CPEJ decreased the production of extracellular polymeric substances but increased bacterial swarming motility. These results led to the hypothesis that CPEJ can reduced intracellular bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP) concentration. The results showed that CPEJ significantly reduced the c-di-GMP level through increased phosphodiesterase activity. Altogether, these findings suggest that CPEJ as a biofilm inhibitor has new potential for pharmacological (e.g. drug, and medication) and industrial applications (e.g. ship hulls, water pipes, and membrane processes biofouling control).}, }
@article {pmid36773754, year = {2023}, author = {Minhaco, VMTR and Maquera-Huacho, PM and Imbriani, MJM and Tonon, CC and Chorilli, M and Rastelli, ANS and Spolidorio, DMP}, title = {Improving antimicrobial activity against endodontic biofilm after exposure to blue light-activated novel curcumin nanoparticle.}, journal = {Photodiagnosis and photodynamic therapy}, volume = {}, number = {}, pages = {103322}, doi = {10.1016/j.pdpdt.2023.103322}, pmid = {36773754}, issn = {1873-1597}, abstract = {New alternative therapies involving natural products and nanobiotechnology open new perspectives to reduce endodontic infections. Curcumin is a natural polyphenol extracted from the dry rhizome of curcuma long Linn with therapeutic properties for application in nanobiotechnology and as a photosensitizer for photodynamic therapy. This study aimed to synthesize a novel polymeric nanoparticle of poly (lactic-co-glycolic acid) (PLGA) loaded with curcumin (NP+Cur), and evaluate its antimicrobial activity against endodontic biofilms. Additionally, its biocompatibility using oral keratinocytes was assessed. The polymeric NP+Cur was prepared by the nanoprecipitation method. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were calculated for the three endodontic bacteria (Enterococcus faecalis, Streptococcus oralis and Actinomyces viscosus). Antibacterial activity of NP+Cur against single- and multispecies biofilm pre-formed on the botton 24-well plate and into dentin tubules of bovine teeth were evaluated by colony forming units and confocal laser scanning microscopy. The pre-irradiation time was 5 minutes followed by exposure to blue light-emitting diode at 450 nm for the photodynamic treatment. Cell viability using oral keratinocytes was assessed by Alamar Blue assay. MIC and MBC showed antibacterial activity of NP+Cur against endodontic bacteria. A treatment of pre-formed biofilms of endodontic bacteria with NP+Cur also significantly decreased bacterial viability. The concentration of 325 μg/mL of photoactivated NP+Cur was the one that most reduced the viability of the endodontic bacteria evaluated. Regarding biocompatibility, NP+Cur 325 μg/mL and pure nanoparticles showed a cell viability greater than 80%. The novel polymeric nanoparticles loaded with curcumin may be a promising adjunct use to treatment of endodontic infections.}, }
@article {pmid36773634, year = {2023}, author = {Shankar, S and Murthy, AN and Rachitha, P and Raghavendra, VB and Sunayana, N and Chinnathambi, A and Alharbi, SA and Basavegowda, N and Brindhadevi, K and Pugazhendhi, A}, title = {Biosynthesis of silk sericin conjugated magnesium oxide nanoparticles for its antioxidant, antiaging, and anti-biofilm activities.}, journal = {Environmental research}, volume = {}, number = {}, pages = {115421}, doi = {10.1016/j.envres.2023.115421}, pmid = {36773634}, issn = {1096-0953}, abstract = {Commercially available silk sericin protein isolated from silk cocoon (SS) was used to synthesize magnesium nitrate (MgNO3)2 solution to form SS-MgO-NPs nanoparticles. UV, XRD, FTIR, SEM, DLS, and EDX were used to confirm the formation of SS-MgO-NPs. The absorption band of SS-MgO-NPs using UV-visible spectra was observed at 310 nm, with an average size of the nanoparticles was 65-88 nm analysed from DLS. The presence of alcohol, CN, and CC, alkanes, alkenes, and cis alkenes, in silk sericin is confirmed by FTIR and may act as a stabilizing agent. Later SS-MgO-NPs were evaluated for antioxidant, antibacterial, anti-aging, and anti-cancer properties. The SS-MgO-NPs inhibited the formation of biofilm of Pseudomonas aeruginosa and Bacillus cereus. The blood compatibility of SS-MgO-NPs, delaying coagulation was observed using human, blood, and goat blood samples. The SS-MgO-NPs exhibited significant anticancer activity on MCF-7 (IC50 207.6 μg/mL) cancer cell lines. Correspondingly, SS-MgO-NPs demonstrated dose-dependent inhibition of the enzymes in the following decreasing order: collagenase > elastase > tyrosinase > hyaluronidase, with IC50 values of 75.3 ± 1.5, 85.3 ± 1.5, 133.6 ± 1.5, and 156.3 ± 1.5 mL[-1], respectively. This supports the compounds' anti-aging properties. So, in in vitro settings, SS-MgO-NPs can be used as an antibacterial, anti-aging, and anticancer agent. Additionally, in-vivo research is necessary to support its therapeutic applications.}, }
@article {pmid36773196, year = {2023}, author = {Li, J and Li, Z and Xie, J and Xia, Y and Gong, W and Tian, J and Zhang, K and Yu, E and Wang, G}, title = {Quorum-quenching potential of recombinant PvdQ-engineered bacteria for biofilm formation.}, journal = {International microbiology : the official journal of the Spanish Society for Microbiology}, volume = {}, number = {}, pages = {}, pmid = {36773196}, issn = {1618-1905}, abstract = {Quorum sensing (QS) is a core mechanism for bacteria to regulate biofilm formation, and therefore, QS inhibition or quorum quenching (QQ) is used as an effective and economically feasible strategy against biofilms. In this study, the PvdQ gene encoding AHL acylase was introduced into Escherichia coli (DE3), and a PvdQ-engineered bacterium with highly efficient QQ activity was obtained and used to inhibit biofilm formation. Gene sequencing and western blot analysis showed that the recombinant pET-PvdQ strain was successfully constructed. The color reaction of Agrobacterium tumefaciens A136 indicated that PvdQ engineering bacteria had shown strong AHL signal molecule quenching activity and significantly inhibited the adhesion (motility) of Pseudomonas aeruginosa and biofilm formation of activated sludge bacteria in Membrane Bio-Reactor (MBR; inhibition rate 51-85%, p < 0.05). In addition, qRT-PCR testing revealed that recombinant PvdQ acylase significantly reduced the transcription level of QS biofilm formation-related genes (cdrA, pqsA, and lasR; p < 0.05). In this study, QQ genetically engineered bacteria enhanced by genetic engineering could effectively inhibit the QS signal transduction mechanism and have the potential to control biofilm formation of pathogenic bacteria in the aquaculture environment, providing an environmentally friendly and alternative antibiotic strategy to suppress biofilm contamination.}, }
@article {pmid36770342, year = {2023}, author = {Sousa-Cardoso, F and Teixeira-Santos, R and Campos, AF and Lima, M and Gomes, LC and Soares, OSGP and Mergulhão, FJ}, title = {Graphene-Based Coating to Mitigate Biofilm Development in Marine Environments.}, journal = {Nanomaterials (Basel, Switzerland)}, volume = {13}, number = {3}, pages = {}, doi = {10.3390/nano13030381}, pmid = {36770342}, issn = {2079-4991}, abstract = {Due to its several economic and ecological consequences, biofouling is a widely recognized concern in the marine sector. The search for non-biocide-release antifouling coatings has been on the rise, with carbon-nanocoated surfaces showing promising activity. This work aimed to study the impact of pristine graphene nanoplatelets (GNP) on biofilm development through the representative marine bacteria Cobetia marina and to investigate the antibacterial mechanisms of action of this material. For this purpose, a flow cytometric analysis was performed and a GNP/polydimethylsiloxane (PDMS) surface containing 5 wt% GNP (G5/PDMS) was produced, characterized, and assessed regarding its biofilm mitigation potential over 42 days in controlled hydrodynamic conditions that mimic marine environments. Flow cytometry revealed membrane damage, greater metabolic activity, and endogenous reactive oxygen species (ROS) production by C. marina when exposed to GNP 5% (w/v) for 24 h. In addition, C. marina biofilms formed on G5/PDMS showed consistently lower cell count and thickness (up to 43% reductions) than PDMS. Biofilm architecture analysis indicated that mature biofilms developed on the graphene-based surface had fewer empty spaces (34% reduction) and reduced biovolume (25% reduction) compared to PDMS. Overall, the GNP-based surface inhibited C. marina biofilm development, showing promising potential as a marine antifouling coating.}, }
@article {pmid36769319, year = {2023}, author = {Bąchor, U and Junka, A and Brożyna, M and Mączyński, M}, title = {The In Vitro Impact of Isoxazole Derivatives on Pathogenic Biofilm and Cytotoxicity of Fibroblast Cell Line.}, journal = {International journal of molecular sciences}, volume = {24}, number = {3}, pages = {}, doi = {10.3390/ijms24032997}, pmid = {36769319}, issn = {1422-0067}, abstract = {The microbial, biofilm-based infections of chronic wounds are one of the major challenges of contemporary medicine. The use of topically administered antiseptic agents is essential to treat wound-infecting microorganisms. Due to observed microbial tolerance/resistance against specific clinically-used antiseptics, the search for new, efficient agents is of pivotal meaning. Therefore, in this work, 15 isoxazole derivatives were scrutinized against leading biofilm wound pathogens Staphylococcus aureus and Pseudomonas aeruginosa, and against Candida albicans fungus. For this purpose, the minimal inhibitory concentration, biofilm reduction in microtitrate plates, modified disk diffusion methods and antibiofilm dressing activity measurement methods were applied. Moreover, the cytotoxicity and cytocompatibility of derivatives was tested toward wound bed-forming cells, referred to as fibroblasts, using normative methods. Obtained results revealed that all isoxazole derivatives displayed antimicrobial activity and low cytotoxic effect, but antimicrobial activity of two derivatives, 2-(cyclohexylamino)-1-(5-nitrothiophen-2-yl)-2-oxoethyl 5-amino-3-methyl-1,2-oxazole-4-carboxylate (PUB9) and 2-(benzylamino)-1-(5-nitrothiophen-2-yl)-2-oxoethyl 5-amino-3-methyl-1,2-oxazole-4-carboxylate (PUB10), was noticeably higher compared to the other compounds analyzed, especially PUB9 with regard to Staphylococcus aureus, with a minimal inhibitory concentration more than x1000 lower compared to the remaining derivatives. The PUB9 and PUB10 derivatives were able to reduce more than 90% of biofilm-forming cells, regardless of the species, displaying at the same time none (PUB9) or moderate (PUB10) cytotoxicity against fibroblasts and high (PUB9) or moderate (PUB10) cytocompatibility against these wound cells. Therefore, taking into consideration the clinical demand for new antiseptic agents for non-healing wound treatment, PUB9 seems to be a promising candidate to be further tested in advanced animal models and later, if satisfactory results are obtained, in the clinical setting.}, }
@article {pmid36768310, year = {2023}, author = {Sedghizadeh, PP and Cherian, P and Roshandel, S and Tjokro, N and Chen, C and Junka, AF and Hu, E and Neighbors, J and Pawlak, J and Russell, RGG and McKenna, CE and Ebetino, FH and Sun, S and Sodagar, E}, title = {Real-Time Impedance-Based Monitoring of the Growth and Inhibition of Osteomyelitis Biofilm Pathogen Staphylococcus aureus Treated with Novel Bisphosphonate-Fluoroquinolone Antimicrobial Conjugates.}, journal = {International journal of molecular sciences}, volume = {24}, number = {3}, pages = {}, doi = {10.3390/ijms24031985}, pmid = {36768310}, issn = {1422-0067}, abstract = {Osteomyelitis is a limb- and life-threatening orthopedic infection predominantly caused by Staphylococcus aureus biofilms. Bone infections are extremely challenging to treat clinically. Therefore, we have been designing, synthesizing, and testing novel antibiotic conjugates to target bone infections. This class of conjugates comprises bone-binding bisphosphonates as biochemical vectors for the delivery of antibiotic agents to bone minerals (hydroxyapatite). In the present study, we utilized a real-time impedance-based assay to study the growth of Staphylococcus aureus biofilms over time and to test the antimicrobial efficacy of our novel conjugates on the inhibition of biofilm growth in the presence and absence of hydroxyapatite. We tested early and newer generation quinolone antibiotics (ciprofloxacin, moxifloxacin, sitafloxacin, and nemonoxacin) and several bisphosphonate-conjugated versions of these antibiotics (bisphosphonate-carbamate-sitafloxacin (BCS), bisphosphonate-carbamate-nemonoxacin (BCN), etidronate-carbamate-ciprofloxacin (ECC), and etidronate-carbamate-moxifloxacin (ECX)) and found that they were able to inhibit Staphylococcus aureus biofilms in a dose-dependent manner. Among the conjugates, the greatest antimicrobial efficacy was observed for BCN with an MIC of 1.48 µg/mL. The conjugates demonstrated varying antimicrobial activity depending on the specific antibiotic used for conjugation, the type of bisphosphonate moiety, the chemical conjugation scheme, and the presence or absence of hydroxyapatite. The conjugates designed and tested in this study retained the bone-binding properties of the parent bisphosphonate moiety as confirmed using high-performance liquid chromatography. They also retained the antimicrobial activity of the parent antibiotic in the presence or absence of hydroxyapatite, albeit at lower levels due to the nature of their chemical modification. These findings will aid in the optimization and testing of this novel class of drugs for future applications to pharmacotherapy in osteomyelitis.}, }
@article {pmid36768176, year = {2023}, author = {Seegers, CII and Lee, DJ and Zarnovican, P and Kirsch, SH and Müller, R and Haselhorst, T and Routier, FH}, title = {Identification of Compounds Preventing A. fumigatus Biofilm Formation by Inhibition of the Galactosaminogalactan Deacetylase Agd3.}, journal = {International journal of molecular sciences}, volume = {24}, number = {3}, pages = {}, doi = {10.3390/ijms24031851}, pmid = {36768176}, issn = {1422-0067}, abstract = {The opportunistic fungus Aspergillus fumigatus causes a set of diseases ranging from allergy to lethal invasive mycosis. Within the human airways, A. fumigatus is embedded in a biofilm that forms not only a barrier against the host immune defense system, but also creates a physical barrier protecting the fungi from chemicals such as antifungal drugs. Novel therapeutic strategies aim at combining drugs that inhibit biofilm synthesis or disrupt existing biofilm with classical antimicrobials. One of the major constituents of A. fumigatus biofilm is the polysaccharide galactosaminogalactan (GAG) composed of α1,4-linked N-acetylgalactosamine, galactosamine, and galactose residues. GAG is synthesized on the cytosolic face of the plasma membrane and is extruded in the extracellular space, where it is partially deacetylated. The deacetylase Agd3 that mediates this last step is essential for the biofilm formation and full virulence of the fungus. In this work, a previously described enzyme-linked lectin assay, based on the adhesion of deacetylated GAG to negatively charged plates and quantification with biotinylated soybean agglutinin was adapted to screen microbial natural compounds, as well as compounds identified in in silico screening of drug libraries. Actinomycin X2, actinomycin D, rifaximin, and imatinib were shown to inhibit Agd3 activity in vitro. At a concentration of 100 µM, actinomycin D and imatinib showed a clear reduction in the biofilm biomass without affecting the fungal growth. Finally, imatinib reduced the virulence of A. fumigatus in a Galleria mellonella infection model in an Agd3-dependent manner.}, }
@article {pmid36766686, year = {2023}, author = {Sanmukh, SG and Admella, J and Moya-Andérico, L and Fehér, T and Arévalo-Jaimes, BV and Blanco-Cabra, N and Torrents, E}, title = {Accessing the In Vivo Efficiency of Clinically Isolated Phages against Uropathogenic and Invasive Biofilm-Forming Escherichia coli Strains for Phage Therapy.}, journal = {Cells}, volume = {12}, number = {3}, pages = {}, doi = {10.3390/cells12030344}, pmid = {36766686}, issn = {2073-4409}, abstract = {Escherichia coli is one of the most common members of the intestinal microbiota. Many of its strains are associated with various inflammatory infections, including urinary or gut infections, especially when displaying antibiotic resistance or in patients with suppressed immune systems. According to recent reports, the biofilm-forming potential of E. coli is a crucial factor for its increased resistance against antibiotics. To overcome the limitations of using antibiotics against resistant E. coli strains, the world is turning once more towards bacteriophage therapy, which is becoming a promising candidate amongst the current personalized approaches to target different bacterial infections. Although matured and persistent biofilms pose a serious challenge to phage therapy, they can still become an effective alternative to antibiotic treatment. Here, we assess the efficiency of clinically isolated phages in phage therapy against representative clinical uropathogenic and invasive biofilm-forming E. coli strains. Our results demonstrate that irrespective of host specificity, bacteriophages producing clear plaques with a high burst size, and exhibiting depolymerizing activity, are good candidates against biofilm-producing E. coli pathogens as verified from our in vitro and in vivo experiments using Galleria mellonella where survival was significantly increased for phage-therapy-treated larvae.}, }
@article {pmid36766272, year = {2023}, author = {Ma, K and Wang, H and Lv, Z and Hu, Y and Wang, H and Shu, F and Zhu, C and Xue, T}, title = {The Two-Component System CpxRA Affects Antibiotic Susceptibility and Biofilm Formation in Avian Pathogenic Escherichia coli.}, journal = {Animals : an open access journal from MDPI}, volume = {13}, number = {3}, pages = {}, doi = {10.3390/ani13030383}, pmid = {36766272}, issn = {2076-2615}, abstract = {Avian pathogenic Escherichia coli (APEC) is one of the common extraintestinal infectious disease pathogens in chickens, geese, and other birds. It can cause a variety of infections, and even the death of poultry, causing enormous economic losses. However, the misuse and abuse of antibiotics in the poultry industry have led to the development of drug resistance in the gut microbes, posing a challenge for the treatment of APEC infections. It has been reported that the CpxRA two-component system has an effect on bacterial drug resistance, but the specific regulatory mechanism remains unclear. In this study, the regulatory mechanism of CpxRA on APEC biofilm formation and EmrKY efflux pump was investigated. The cpxRA knockout strain of E. coli APEC40 was constructed, and the molecular regulatory mechanism of CpxR on biofilms and efflux pump-coding genes were identified by biofilm formation assays, drug susceptibility test, real-time reverse transcription quantitative PCR, and electrophoretic mobility shift assay (EMSA). The results indicated that CpxR can directly bind to the promoter region of emrKY and negatively regulate the sensitivity of bacteria to ofloxacin and erythromycin. These results confirm the important regulatory role of the CpxRA two-component system under antibiotic stress in APEC.}, }
@article {pmid36764616, year = {2023}, author = {Wang, J and Li, L and Chi, B and Shan, J and Yi, X and Liu, Y and Zhou, H}, title = {Metagenomic insights into the effects of benzyl dodecyl dimethyl ammonium bromide (BDAB) shock on bacteria-driven nitrogen removal in a moving-bed biofilm reactor (MBBR).}, journal = {Chemosphere}, volume = {320}, number = {}, pages = {138098}, doi = {10.1016/j.chemosphere.2023.138098}, pmid = {36764616}, issn = {1879-1298}, abstract = {The use of disinfectants made from quaternary ammonium compounds (QACs) has greatly increased since the outbreak of SARS-CoV-2. However, the effect of QACs on wastewater treatment performance is still unclear. In this study, a commonly used QAC, i.e., benzyl dodecyl dimethyl ammonium bromide (BDAB), was added to a moving-bed biofilm reactor (MBBR) to investigate BDAB's effect on nutrient removal. When the BDAB concentration was increased to 50 mg L[-1], the ammonia removal efficiency (ARE) greatly decreased, as did the nitrate production rate constants (NPR). This inhibition was partly recovered by decreasing the BDAB concentration to 30 mg L[-1]. Metagenomic sequencing revealed the functional genera present during different stages of the control (Rc) and BDAB-added reactors (Re). The enriched genera (Rudaea, Nitrosospira, Sphingomonas, and Rhodanobacter) in Rc mainly related to the nitrogen metabolism, while the enriched genera in Re was BDAB-concentration dependent. Functional genes analysis suggested that a lack of ammonia oxidase-encoding genes (amoABC) may have caused a decrease in ARE in Re, while the efflux pump-encoding genes emrE, mdfA, and oprM and a gene encoding BAC oxygenase (oxyBAC) were responsible for BDAB resistance. The increase in the total abundance of antibiotic resistance genes (ARGs) in Re revealed a potential risk arising from BDAB. Overall, this study revealed the potential effect and ecological risks of BDAB introduction in WWTPs.}, }
@article {pmid36764613, year = {2023}, author = {Xu, Y and Gu, Y and Peng, L and Wang, N and Chen, S and Liang, C and Liu, Y and Ni, BJ}, title = {Unravelling ciprofloxacin removal in a nitrifying moving bed biofilm reactor: Biodegradation mechanisms and pathways.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {138099}, doi = {10.1016/j.chemosphere.2023.138099}, pmid = {36764613}, issn = {1879-1298}, abstract = {Although moving bed biofilm reactors (MBBRs) have shown excellent antibiotic removal potentials, the information on underlying mechanisms is yet limited. This work assessed the removal of ciprofloxacin in an enriched nitrifying MBBR by clarifying the contribution of adsorption and microbial-induced biodegradation. Results demonstrated the considerable biomass adsorption (55%) in first 30 min. Limiting nitrite oxidizing bacteria growth or inhibiting nitrification would lead to lower adsorption capacities. The highest ciprofloxacin biodegradation rate constant was 0.082 L g SS[-1] h[-1] in the presence of ammonium, owing to ammonia oxidizing bacteria (AOB)-induced cometabolism, while heterotrophs played an insignificant role (∼9%) in ciprofloxacin biodegradation. The developed model also suggested the importance of AOB-induced cometabolism and metabolism over heterotrophs-induced biodegradation by analyzing the respective biodegradation coefficients. Cometabolic biodegradation pathways of ciprofloxacin mainly involved the piperazine ring cleavage, probably alleviating antimicrobial activities. It implies the feasibility of nitrifying biofilm systems towards efficient antibiotic removal from wastewater.}, }
@article {pmid36764542, year = {2023}, author = {Robichon, C and Robin, J and Dolédec, S}, title = {Relative effect of hydraulics, physico-chemistry and other biofilm algae on benthic cyanobacteria assemblages in a regulated river.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {162142}, doi = {10.1016/j.scitotenv.2023.162142}, pmid = {36764542}, issn = {1879-1026}, abstract = {The development of benthic cyanobacteria currently raises concern worldwide because of their potential to produce toxins. As a result, understanding which measures of biotic and abiotic parameters influence the development of cyanobacterial assemblages is of great importance to guide management actions. In this study, we investigate the relative contributions of abiotic and biotic parameters that may drive the development of cyanobacterial assemblages in river biofilms. First, a 2D hydrodynamic model allowed us to retrace changes in depths and velocities according to discharge at a 4 m[2] resolution. From this model, we set up three hydraulic zones in each of the 4 reaches investigated along a 50-km-long river stretch. We further used univariate, multivariate and variance partitioning analyses to assess the contribution of past and present hydraulics, present physical and chemical parameters and algae to the temporal variability of cyanobacterial assemblage composition. The cyanobacterial assemblages were generally dominated by Phormidium sp., Lyngbya sp., Planktolyngbya sp. and Oscillatoria sp., four genera known to contain potentially toxic species. The highest biovolumes of cyanobacteria were present in low velocity zones in early summer and shifted to high velocity zones in late summer, highlighting the major influence of hydraulic parameters on benthic cyanobacteria settlement and development in rivers. Considering the identified genera, biofilms present a potentially high risk of toxin production. Relations between cyanobacterial development, toxin production and environmental parameters need to be further assessed to better estimate this risk.}, }
@article {pmid36763802, year = {2022}, author = {Lagudas, MFG and Bureros, KJC}, title = {Inhibition of Candida albicans and Staphylococcus epidermidis mixed biofilm formation in a catheter disk model system treated with EtOH-EDTA solution.}, journal = {Letters in applied microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/lambio/ovac074}, pmid = {36763802}, issn = {1472-765X}, abstract = {Microbial colonization and the formation of biofilms on catheter surfaces pose a great risk for medical-related infections. We aimed (a) to evaluate polymicrobial biofilm formation of Candida albicans and Staphylococcus epidermidis and (b) to investigate the inhibition and effects of ethanol (EtOH) and EtOH-EDTA solutions on biofilms. Catheter disks were made and used as a substrate for biofilm formation. Varying concentrations of EtOH and EtOH-EDTA solutions were compared in deterring biofilm formation. The EtOH-EDTA solutions were further tested to remove mature and preformed biofilms. Compared to their monospecies counterparts, biofilm concentration significantly increases when C. albicans is co-cultured with S. epidermidis. Moreover, all treatments with EtOH-EDTA solution significantly lowered biofilm formation compared to EtOH alone (P ≤ 0.05). Lastly, biofilm was dramatically reduced when treated with 20%, 30%, 40%, and 50% EtOH-EDTA solutions (P ≤ 0.05). Our findings suggest that biofilms become more resilient to treatment when formed by multiple organisms. Nonetheless, treatment with EtOH-EDTA is effective against these polymicrobial biofilms.}, }
@article {pmid36762094, year = {2022}, author = {Li, X and Gu, N and Huang, TY and Zhong, F and Peng, G}, title = {Pseudomonas aeruginosa: A typical biofilm forming pathogen and an emerging but underestimated pathogen in food processing.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1114199}, pmid = {36762094}, issn = {1664-302X}, abstract = {Pseudomonas aeruginosa (P. aeruginosa) is a notorious gram-negative pathogenic microorganism, because of several virulence factors, biofilm forming capability, as well as antimicrobial resistance. In addition, the appearance of antibiotic-resistant strains resulting from the misuse and overuse of antibiotics increases morbidity and mortality in immunocompromised patients. However, it has been underestimated as a foodborne pathogen in various food groups for instance water, milk, meat, fruits, and vegetables. Chemical preservatives that are commonly used to suppress the growth of food source microorganisms can cause problems with food safety. For these reasons, finding effective, healthy safer, and natural alternative antimicrobial agents used in food processing is extremely important. In this review, our ultimate goal is to cover recent advances in food safety related to P. aeruginosa including antimicrobial resistance, major virulence factors, and prevention measures. It is worth noting that food spoilage caused by P. aeruginosa should arouse wide concerns of consumers and food supervision department.}, }
@article {pmid36761303, year = {2023}, author = {Burden, B and Rodriguez-Alvarez, JS and Levi, N and Gayzik, FS}, title = {Application of survival analysis to model proliferation likelihood of Escherichia coli biofilm following laser-induced hyperthermia treatment.}, journal = {Frontiers in bioengineering and biotechnology}, volume = {11}, number = {}, pages = {1001017}, pmid = {36761303}, issn = {2296-4185}, abstract = {Eighty percent of bacterial infections associated with living tissue and medical devices are linked to drug-resistant biofilms, leading to lengthy and costly recoveries. Laser-induced hyperthermia can disrupt cell proliferation within biofilms and increase susceptibility to antibiotics. However, there can be bacterial survival differences dependent upon laser irradiation times, and prolonged time at elevated temperature can damage healthy tissue. The objective of this study was to use survival analysis to model the impact of temperature increases on reducing viable biofilm bacteria. In vitro biofilms of Escherichia coli were grown on silicone discs or silicone doped with photothermal poly(3,4-ethylenedioxythiophene) hydrate (PEDOT) nanotubes, and subjected to laser-induced hyperthermia, using a 3 W continuous wave laser at 800 nm for varying times. The number of colony forming units per milliliter (CFU/mL) and maximum temperature were measured after each trial. Survival analysis was employed to estimate bacterial cell proliferation post-treatment to provide a quantitative framework for future studies evaluating photothermal inactivation of bacterial biofilms. The results demonstrate the first application of survival analysis for predicting the likelihood of bacterial cell proliferation based on temperature.}, }
@article {pmid36756936, year = {2023}, author = {Rao, TS and Feser, R}, title = {Biofilm formation by sulphate reducing bacteria on different metals and its prospective role in titanium corrosion.}, journal = {Environmental technology}, volume = {}, number = {}, pages = {1-34}, doi = {10.1080/09593330.2023.2178976}, pmid = {36756936}, issn = {1479-487X}, abstract = {This study describes the biofilm formation by sulphate reducing bacteria (SRB) on different materials, which has implications for the biomedical, pharmaceutical, food and chemical process industries. SRB was chosen as a model organism being an anaerobic bacterium. Biofilm formation on different materials and corrosion of titanium by SRB were monitored with time using confocal laser scanning microscopy and fluorescent FISH probes were used to authenticate the SRB strain. The thickness of the mono-culture SRB biofilm has ranged from 4-24 µm during the period 12-84 hrs, however, the maximum biofilm thickness (24 µm) was recorded after 60 hrs of growth. Planktonic growth of the SRB strain showed a log phase up to 48 hrs and the sulphide production ranged from 2 to 14 mg l[-1]. For a comparative account, the SRB biofilm formation on copper was chosen as a positive control. Finally, the putative role of extracellular electron transfer by SRB in the biocorrosion process and the plausible mechanism of pitting corrosion of titanium are described in detail.}, }
@article {pmid36756619, year = {2023}, author = {de Melo, CC and de Sousa, BR and da Costa, GL and Oliveira, MME and de Lima-Neto, RG}, title = {Colonized patients by Candida auris: Third and largest outbreak in Brazil and impact of biofilm formation.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1033707}, pmid = {36756619}, issn = {2235-2988}, abstract = {OBJECTIVE: To describe the clinical-epidemiological features of patients colonized by Candida auris in the largest outbreak in Brazil and to show the biofilm formation capacity of yeast strains.<br><br>METHODS: Clinical yeasts suspected of C. auris isolated from urine and surveillance samples were seeded on chromogenic media at 30&#xb0;C and Sabouraud agar at 42&#xb0;C. matrix-assisted laser desorption/ionization-time of flight mass spectometry was used for reliable identification. After proteomic confirmation, the genomic approach and culture on Chromagar Candida Plus media were carried out. Biofilm formation was investigated based on metabolic activity, and the clinical-epidemiological profile of patients was described.<br><br>RESULTS: A total of 11 C. auris clinical yeasts from nine patients were identified between the end of December 2021 and March 2022. Two clinical yeasts were isolates from urine and nine clinical yeasts were isolates from axillary and inguinal surveillance swabs. No case is related to previous Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, all the yeasts showed a high ability of biofilm formation.<br><br>CONCLUSION: C. auris requires great vigilance as its high capacity to colonize and form biofilms contributes to its dissemination. The rapid and precise identification of this species is essential for the management, control, and prevention of infections.}, }
@article {pmid36756618, year = {2023}, author = {Zaki, BM and Fahmy, NA and Aziz, RK and Samir, R and El-Shibiny, A}, title = {Characterization and comprehensive genome analysis of novel bacteriophage, vB_Kpn_ZCKp20p, with lytic and anti-biofilm potential against clinical multidrug-resistant Klebsiella pneumoniae.}, journal = {Frontiers in cellular and infection microbiology}, volume = {13}, number = {}, pages = {1077995}, pmid = {36756618}, issn = {2235-2988}, abstract = {INTRODUCTION: The rise of infections by antibiotic-resistant bacterial pathogens is alarming. Among these, Klebsiella pneumoniae is a leading cause of death by hospital-acquired infections, and its multidrug-resistant strains are flagged as a global threat to human health, which necessitates finding novel antibiotics or alternative therapies. One promising therapeutic alternative is the use of virulent bacteriophages, which specifically target bacteria and coevolve with them to overcome potential resistance. Here, we aimed to discover specific bacteriophages with therapeutic potential against multiresistant K. pneumoniae clinical isolates.<br><br>METHODS AND RESULTS: Out of six bacteriophages that we isolated from urban and medical sewage, phage vB_Kpn_ZCKp20p had the broadest host range and was thus characterized in detail. Transmission electron microscopy suggests vB_Kpn_ZCKp20p to be a tailed phage of the siphoviral morphotype. In vitro evaluation indicated a high lytic efficiency (30 min latent period and burst size of &#x223c;100 PFU/cell), and extended stability at temperatures up to 70&#xb0;C and a wide range of (2-12) pH. Additionally, phage vB_Kpn_ZCKp20p possesses antibiofilm activity that was evaluated by the crystal violet assay and was not cytotoxic to human skin fibroblasts. The whole genome was sequenced and annotated, uncovering one tRNA gene and 33 genes encoding proteins with assigned functions out of 85 predicted genes. Furthermore, comparative genomics and phylogenetic analysis suggest that vB_Kpn_ZCKp20p most likely represents a new species, but belongs to the same genus as Klebsiella phages ZCKP8 and 6691. Comprehensive genomic and bioinformatics analyses substantiate the safety of the phage and its strictly lytic lifestyle.<br><br>CONCLUSION: Phage vB_Kpn_ZCKp20p is a novel phage with potential to be used against biofilm-forming K. pneumoniae and could be a promising source for antibacterial and antibiofilm products, which will be individually studied experimentally in future studies.}, }
@article {pmid36756165, year = {2022}, author = {Rychshanova, R and Mendybayeva, A and Miciński, B and Mamiyev, N and Shevchenko, P and Bermukhametov, Z and Orzechowski, B and Miciński, J}, title = {Antibiotic resistance and biofilm formation in Staphylococcus aureus isolated from dairy cows at the stage of subclinical mastitis in northern Kazakhstan.}, journal = {Archives animal breeding}, volume = {65}, number = {4}, pages = {439-448}, pmid = {36756165}, issn = {2363-9822}, abstract = {Staphylococcus aureus is an important causative agent of subclinical bovine mastitis worldwide. The aim of this research was to study the ability of S. aureus to form biofilms. Additionally, we examined the genes involved in cell resistance and sensitivity to antibiotics. Samples were collected from December 2020 to May 2021 from Simmental and black-and-white cows. The study was carried out on a total number of 643 cows, of which 278 (23 %) were in the subclinical mastitis stage. Finally, 64 S. aureus isolates were isolated and identified. The highest level of phenotypic resistance was observed to antibiotics of the tetracycline (tetracycline - 48.4 %, doxycycline - 32.8 %) and β -lactam (ampicillin - 45.3 %, penicillin - 45.3 %) groups. The genes encoding antibiotic resistance were characterized with the polymerase chain reaction method: blaZ in 30 isolates, mecA in 1 isolate, ermC in 15 isolates, aph (3) in 2 isolates, tetK in 19 isolates, tetM in 9 isolates. The tested S. aureus isolates had the ability to form biofilms in 76.6 % (49 / 64) of cases. Of these, 69.4 % were resistant to at least one antibiotic. The obtained results have shown that S. aureus, identified in cows with subclinical mastitis, was resistant mainly to tetracycline and β -lactam antibiotics. In addition, S. aureus isolates expressed resistance genes to the above drugs and had the ability to form biofilm. This study will help to identify the extent of antibiotic resistance and monitor S. aureus contamination of raw milk.}, }
@article {pmid36755419, year = {2023}, author = {Khari, A and Biswas, B and Gangwar, G and Thakur, A and Puria, R}, title = {Candida auris biofilm: a review on model to mechanism conservation.}, journal = {Expert review of anti-infective therapy}, volume = {}, number = {}, pages = {}, doi = {10.1080/14787210.2023.2179036}, pmid = {36755419}, issn = {1744-8336}, abstract = {INTRODUCTION: Candida auris is included in the fungal infection category "critical" by WHO because of associated high drug tolerance and spread at an alarming rate which if remains untouched may result in serious outbreaks. Since its discovery in 2009, several assiduous efforts by mycologists across the world have deciphered its biology including growth physiology, drug tolerance, biofilm formation, etc. The differential response of various strains from different clades poses a hurdle in drawing a final conclusion.<br><br>AREAS COVERED: This review provides brief insights into the understanding of C. auris biofilm. It includes information on various models developed to understand the biofilms and conservation of different signaling pathways. Significant development has been made in the recent past with the generation of relevant in vivo and ex vivo models. The role of signaling pathways in the development of biofilm is largely unknown.<br><br>EXPERT OPINION: The selection of an appropriate model system is a must for the accuracy and reproducibility of results. The conservation of major signaling pathways in C. auris with respect to C. albicans and S. cerevisiae highlights that initial inputs acquired from orthologs will be valuable in getting insights into the mechanism of biofilm formation and associated pathogenesis.}, }
@article {pmid36754199, year = {2023}, author = {Yan, C and Li, X and Huang, J and Cao, C and Ji, X and Qian, X and Wei, Z}, title = {Long-term synergic removal performance of N, P, and CuO nanoparticles in constructed wetlands along with temporal record of Cu pollution in substrate-biofilm.}, journal = {Environmental pollution (Barking, Essex : 1987)}, volume = {}, number = {}, pages = {121231}, doi = {10.1016/j.envpol.2023.121231}, pmid = {36754199}, issn = {1873-6424}, abstract = {With continued exposure to CuO nanoparticles (NPs) which were toxic to organisms, the performance of wastewater treatment facility might be affected. In present study, the feasibility of constructed wetlands (CWs) for wastewater treatment containing CuO NPs and common pollutants was comprehensively explored. It was found that CWs removed 98.80-99.84% CuO NPs and 90.91-91.83% COD within 300 days. However, N and P removals were affected to varying degrees by CuO NPs. N removal was inhibited only by 0.5 mg/L CuO NPs with 19.75% decreases on the mean from day 200-300. P removal was reduced by 3.80-50.75% and 1.92-7.19% under exposure of 0.5 and 5 mg/L CuO NPs throughout the experiment. Moreover, CuO NPs changed the adsorption potential of P and ammonium-N on sand-biofilm. Cu concentrations in spatial distribution decreased, while they in temporal distribution increased from 36.94 to 97.78 μg/g and from 70.92 to 282.66 μg/g at middle sand layer exposed to 0.5 and 5 mg/L CuO NPs. Mass balance model showed that substrate-biofilm was main pollutant sink for CuO NPs, N, and P. The minor Cu was absorbed by plants exposed to 0.5 and 5 mg/L CuO NPs, which decreased N by 53.40% and 18.51%，and P by 52.35% and 21.62%. Sequencing analysis indicated that CuO NPs also altered spatial microbial community. N-degrading bacteria (Rhodanobacter, Thauera, Nitrospira) changed differently, while phosphate accumulation organisms (Acinetobacter, Pseudomonas, Microlunatus) reduced. Overall, the negative effects of CuO NPs on N and P removal should be noted when CWs as ecological technologies are used to treat CuO NPs-containing wastewater.}, }
@article {pmid36753070, year = {2023}, author = {Marin-Dett, FH and Campanella, JEM and Trovatti, E and Bertolini, MC and Vergani, CE and Barbugli, PA}, title = {Extracellular lipids of Candida albicans biofilm induce lipid droplet formation and decreased response to a topoisomerase I inhibitor in dysplastic and neoplastic oral cells.}, journal = {Journal of applied oral science : revista FOB}, volume = {30}, number = {}, pages = {e20220319}, doi = {10.1590/1678-7757-2022-0319}, pmid = {36753070}, issn = {1678-7765}, abstract = {OBJECTIVE: Some microorganisms, i.e., Candida albicans, have been associated with cancer onset and development, although whether the fungus promotes cancer or whether cancer facilitates the growth of C. albicans is unclear. In this context, microbial-derived molecules can modulate the growth and resistance of cancer cells. This study isolated extracellular lipids (ECL) from a 36-h Candida albicans biofilm incubated with oral dysplastic (DOK) and neoplastic (SCC 25) cells, which were further challenged with the topoisomerase I inhibitor camptothecin (CPT), a lipophilic anti-tumoral molecule.<br><br>METHODOLOGY: ECL were extracted from a 36-h Candida albicans biofilm with the methanol/chloroform precipitation method and identified with Nuclear Magnetic Resonance (1H-NMR). The MTT tetrazolium assay measured ECL cytotoxicity in DOK and SCC 25 cells, alamarBlue&#x2122; assessed cell metabolism, flow cytometry measured cell cycle, and confocal microscopy determined intracellular features.<br><br>RESULTS: Three major classes of ECL of C. albicans biofilm were found: phosphatidylinositol (PI), phosphatidylcholine (PC), and phosphatidylglycerol (PG). The ECL of C. albicans biofilm had no cytotoxic effect on neither cell after 24 hours, with a tendency to disturb the SCC 25 cell cycle profile (without statistical significance). The ECL-induced intracellular lipid droplet (LD) formation on both cell lines after 72 hours. In this context, ECL enhanced cell metabolism, decreased the response to CPT, and modified intracellular drug distribution.<br><br>CONCLUSION: The ECL (PI, PC, and PG) of 36-h Candida albicans biofilm directly interacts with dysplastic and neoplastic oral cells, highlighting the relevance of better understanding C. albicans biofilm signaling in the microenvironment of tumor cells.}, }
@article {pmid36749305, year = {2023}, author = {Samadi, A and Kermanshahi Pour, A and Beims, RF and Xu, CC}, title = {Delignified porous wood as biofilm support for 1,4-dioxane-degrading bacterial consortium.}, journal = {Environmental technology}, volume = {}, number = {}, pages = {1-41}, doi = {10.1080/09593330.2023.2178330}, pmid = {36749305}, issn = {1479-487X}, abstract = {Delignified porous wood samples were used as carriers for biofilm formation of a bacterial consortium with the ability to degrade 1,4-dioxane (DX). The delignification treatment of the natural wood resulted in higher porosity, formation of macropores, increase in surface roughness and hydrophilicity of the treated wood pieces. These superior properties of two types of treated carriers (respectively, A and B) compared to the untreated wood resulted in 2.19 ± 0.52- and 2.66 ± 0.23-fold higher growth of biofilm. Moreover, analysis of the fatty acid profiles indicated an increase in proportion of the saturated fatty acids during the biofilm formation, characterizing an enhancement in rigidity and hydrophobicity of the biofilms. DX initial concentration of 100 mg/L was completely degraded (detection limit 0.01 mg/L) in 24 and 32 h using the treated A and B woods, while only 25.84 ± 5.95% was removed after 32 h using the untreated wood. However, fitting the DX biodegradation data to the Monod model showed a lower maximum specific growth rate for biofilm (0.0276 ± 0.0018 1/h) versus planktonic (0.0382 ± 0.0024 1/h), because of gradual accumulation of inactive cells in the biofilm. Findings of this study can contribute to the knowledge of biofilm formation regarding the physical/chemical properties of biofilm carriers and be helpful to the ongoing research on bioremediation of DX.}, }
@article {pmid36749062, year = {2023}, author = {Tello-Díaz, C and Palau, M and Muñoz, E and Gomis, X and Gavaldà, J and Fernández-Hidalgo, N and Bellmunt-Montoya, S}, title = {Methicillin-Susceptible Staphylococcus aureus Biofilm Formation on Vascular Grafts: an In Vitro Study.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0393122}, doi = {10.1128/spectrum.03931-22}, pmid = {36749062}, issn = {2165-0497}, abstract = {The aim of this study was to quantify in vitro biofilm formation by methicillin-susceptible Staphylococcus aureus (MSSA) on the surfaces of different types of commonly used vascular grafts. We performed an in vitro study with two clinical strains of MSSA (MSSA2 and MSSA6) and nine vascular grafts: Dacron (Hemagard), Dacron-heparin (Intergard heparin), Dacron-silver (Intergard Silver), Dacron-silver-triclosan (Intergard Synergy), Dacron-gelatin (Gelsoft Plus), Dacron plus polytetrafluoroethylene (Fusion), polytetrafluoroethylene (Propaten; Gore), Omniflow II, and bovine pericardium (XenoSure). Biofilm formation was induced in two phases: an initial 90-minute adherence phase and a 24-hour growth phase. Quantitative cultures were performed, and the results were expressed as log10 CFU per milliliter. The Dacron-silver-triclosan graft and Omniflow II were associated with the least biofilm formation by both MSSA2 and MSSA6. MSSA2 did not form a biofilm on the Dacron-silver-triclosan graft (0 CFU/mL), and the mean count on the Omniflow II graft was 3.89 CFU/mL (standard deviation [SD] 2.10). The mean count for the other grafts was 7.01 CFU/mL (SD 0.82). MSSA6 formed a biofilm on both grafts, with 2.42 CFU/mL (SD 2.44) on the Dacron-silver-triclosan graft and 3.62 CFU/mL (SD 2.21) on the Omniflow II. The mean biofilm growth on the remaining grafts was 7.33 CFU/mL (SD 0.28). The differences in biofilm formation on the Dacron-silver-triclosan and Omniflow II grafts compared to the other tested grafts were statistically significant. Our findings suggest that of the vascular grafts we studied, the Dacron-silver-triclosan and Omniflow II grafts might prevent biofilm formation by MSSA. Although further studies are needed, these grafts seem to be good candidates for clinical use in vascular surgeries at high risk of infections due to this microorganism. IMPORTANCE The Dacron silver-triclosan and Omniflow II vascular grafts showed the greatest resistance to in vitro methicillin-susceptible Staphylococcus aureus biofilm formation compared to other vascular grafts. These findings could allow us to choose the most resistant to infection prosthetic graft.}, }
@article {pmid36748569, year = {2023}, author = {Chávez-Jacobo, VM and Becerra-Rivera, VA and Guerrero, G and Dunn, MF}, title = {The Sinorhizobium meliloti NspS-MbaA system affects biofilm formation, exopolysaccharide production and motility in response to specific polyamines.}, journal = {Microbiology (Reading, England)}, volume = {169}, number = {1}, pages = {}, doi = {10.1099/mic.0.001293}, pmid = {36748569}, issn = {1465-2080}, abstract = {We previously showed that specific polyamines (PAs) present in the extracellular environment markedly affect extracellular polysaccharide (EPS) production, biofilm formation and motility in Sinorhizobium meliloti Rm8530. We hypothesized that extracellular PA signals were sensed and transduced by the NspS and MbaA proteins, respectively, which are homologs of the PA-sensing, c-di-GMP modulating NspS-MbaA proteins described in Vibrio cholerae. Here we show that the decrease in biofilm formation and EPS production in the quorum-sensing (QS)-deficient S. meliloti wild-type strain 1021 in cultures containing putrescine or spermine did not occur in a 1021 nspS mutant (1021 nspS). The transcriptional expression of nspS in strain 1021 was significantly increased in cultures containing either of these polyamines, but not by exogenous cadaverine, 1,3-diaminopropane (DAP), spermidine (Spd) or norspermidine (NSpd). Cell aggregation in liquid cultures did not differ markedly between strain 1021 and 1021 nspS in the presence or absence of PAs. The S. meliloti QS-proficient Rm8530 wild-type and nspS mutant (Rm8530 nspS) produced similar levels of biofilm under control conditions and 3.2- and 2.2-fold more biofilm, respectively, in cultures with NSpd, but these changes did not correlate with EPS production. Cells of Rm8530 nspS aggregated from two- to several-fold more than the wild-type in cultures without PAs or in those containing Spm. NSpd, Spd and DAP differently affected swimming and swarming motility in strains 1021 and Rm8530 and their respective nspS mutants. nspS transcription in strain Rm8530 was greatly reduced by exogenous Spm. Bioinformatic analysis revealed similar secondary structures and functional domains in the MbaA proteins of S. meliloti and V. cholerae, while their NspS proteins differed in some residues implicated in polyamine recognition in the latter species. NspS-MbaA homologs occur in a small subset of soil and aquatic bacterial species that commonly interact with eukaryotes. We speculate that the S. meliloti NspS-MbaA system modulates biofilm formation, EPS production and motility in response to environmental or host plant-produced PAs.}, }
@article {pmid36748557, year = {2022}, author = {Abdian, PL and Malori, MS and Caramelo, JJ and Checchi, AM and Russo, DM and Zorreguieta, A and Berretta, MF and Benintende, G}, title = {Fusion of a bacterial cadherin-like domain and green fluorescent protein as a specific probe to study biofilm matrix formation in Rhizobium spp.}, journal = {Microbiology (Reading, England)}, volume = {168}, number = {12}, pages = {}, doi = {10.1099/mic.0.001284}, pmid = {36748557}, issn = {1465-2080}, abstract = {Rhizobium adhering proteins or 'Raps' are secreted proteins identified in a very restricted group of rhizobial strains, specifically those belonging to R. leguminosarum and R. etli. The distinctive feature of members of the Rap family is the presence of one or two cadherin-like domains or CHDLs that are also present in numerous extracellular bacterial and archaeal proteins and were proposed to confer carbohydrate binding ability. We have previously made an in-depth characterization of RapA2, a calcium-binding lectin, composed by two CHDLs, involved in biofilm matrix remodelling in R. leguminosarum bv. viciae 3841. In this study, CHDLs derived from RapA2 were analysed in detail, finding significant structural and functional differences despite their considerable sequence similarity. Only the carboxy-terminal CHDL retained properties similar to those displayed by RapA2. Our findings were used to obtain a novel fluorescent probe to study biofilm matrix development by confocal laser scanning microscopy, and also to shed some light on the role of the ubiquitous CHDL domains in bacterial secreted proteins.}, }
@article {pmid36748304, year = {2023}, author = {Deng, Y and Fu, Y and Chua, SL and Khoo, BL}, title = {Biofilm Potentiates Cancer-Promoting Effects of Tumor-Associated Macrophages in a 3D Multi-Faceted Tumor Model.}, journal = {Small (Weinheim an der Bergstrasse, Germany)}, volume = {}, number = {}, pages = {e2205904}, doi = {10.1002/smll.202205904}, pmid = {36748304}, issn = {1613-6829}, abstract = {Components of the tumor microenvironment (TME), such as tumor-associated macrophages (TAMs), influence tumor progression. The specific polarization and phenotypic transition of TAMs in the tumor microenvironment lead to two-pronged impacts that can promote or hinder cancer development and treatment. Here, a novel microfluidic multi-faceted bladder tumor model (TAM[PIEB]) is developed incorporating TAMs and cancer cells to evaluate the impact of bacterial distribution on immunomodulation within the tumor microenvironment in vivo. It is demonstrated for the first time that biofilm-induced inflammatory conditions within tumors promote the transition of macrophages from a pro-inflammatory M1-like to an anti-inflammatory/pro-tumor M2-like state. Consequently, multiple roles and mechanisms by which biofilms promote cancer by inducing pro-tumor phenotypic switch of TAMs are identified, including cancer hallmarks such as reducing susceptibility to apoptosis, enhancing cell viability, and promoting epithelial-mesenchymal transition and metastasis. Furthermore, biofilms formed by extratumoral bacteria can shield tumors from immune attack by TAMs, which can be visualized through various imaging assays in situ. The study sheds light on the underlying mechanism of biofilm-mediated inflammation on tumor progression and provides new insights into combined anti-biofilm therapy and immunotherapy strategies in clinical trials.}, }
@article {pmid36747833, year = {2023}, author = {Wang, L and Wong, YC and Correira, JM and Wancura, M and Geiger, CJ and Webster, SS and Butler, BJ and Oâ Toole, GA and Langford, RM and Brown, KA and Dortdivanlioglu, B and Webb, L and Cosgriff-Hernandez, E and Gordon, VD}, title = {Bacterial mechanosensing of surface stiffness promotes signaling and growth leading to biofilm formation by Pseudomonas aeruginosa.}, journal = {bioRxiv : the preprint server for biology}, volume = {}, number = {}, pages = {}, doi = {10.1101/2023.01.26.525810}, pmid = {36747833}, abstract = {UNLABELLED: The attachment of bacteria onto a surface, consequent signaling, and the accumulation and growth of the surface-bound bacterial population are key initial steps in the formation of pathogenic biofilms. While recent reports have hinted that the stiffness of a surface may affect the accumulation of bacteria on that surface, the processes that underlie bacterial perception of and response to surface stiffness are unknown. Furthermore, whether, and how, the surface stiffness impacts biofilm development, after initial accumulation, is not known. We use thin and thick hydrogels to create stiff and soft composite materials, respectively, with the same surface chemistry. Using quantitative microscopy, we find that the accumulation, motility, and growth of the opportunistic human pathogen Pseudomonas aeruginosa respond to surface stiffness, and that these are linked through cyclic-di-GMP signaling that depends on surface stiffness. The mechanical cue stemming from surface stiffness is elucidated using finite-element modeling combined with experiments - adhesion to stiffer surfaces results in greater changes in mechanical stress and strain in the bacterial envelope than does adhesion to softer surfaces with identical surface chemistry. The cell-surface-exposed protein PilY1 acts as a mechanosensor, that upon surface engagement, results in higher cyclic-di-GMP levels, lower motility, and greater accumulation on stiffer surfaces. PilY1 impacts the biofilm lag phase, which is extended for bacteria attaching to stiffer surfaces. This study shows clear evidence that bacteria actively respond to different stiffness of surfaces where they adhere via perceiving varied mechanical stress and strain upon surface engagement.<br><br>IMPORTANCE: Bacteria colonize many types of biological and medical surfaces with a large range of stiffnesses. Colonization leads to the formation of biofilms, which cause costly and life-impairing chronic infections. However, whether and how bacteria can sense and respond to the mechanical cue provided by surface stiffness has remained unknown. We find that bacteria do indeed respond to surface stiffness in a way that is both consistent with expectations based on equilibrium continuum mechanics and that quantitatively impacts multiple aspects of early biofilm formation. This is a new understanding for the nascent field of bacterial mechanobiology. Furthermore, this finding suggests the possibility of a new category of approaches to hindering biofilm development by tuning the mechanical properties of biomedical surfaces.}, }
@article {pmid36746918, year = {2023}, author = {Lee, JW and Jeong, SY and Kim, TG}, title = {Epifluorescence Microscopy with Image Analysis as a Promising Method for Multispecies Biofilm Quantification.}, journal = {Journal of microbiology and biotechnology}, volume = {33}, number = {3}, pages = {1-8}, doi = {10.4014/jmb.2209.09045}, pmid = {36746918}, issn = {1738-8872}, abstract = {Epifluorescence microscopy with image analysis was evaluated as a biofilm quantification method (i.e., quantification of surface area colonized by biofilms), in comparison with crystal violet (CV) staining. We performed different experiments to generate multispecies biofilms with natural and artificial bacterial assemblages. First, four species were inoculated daily in 16 different sequences to form biofilms (surface colonization, 0.1%-56.6%). Second, a 9-species assemblage was allowed to form biofilms under 10 acylase treatment episodes (33.8%-55.6%). The two methods comparably measured the quantitative variation in biofilms, exhibiting a strong positive relationship (R[2] ≥ 0.7). Moreover, the two methods exhibited similar levels of variation coefficients. Finally, six synthetic and two natural consortia were allowed to form biofilms for 14 days, and their temporal dynamics were monitored. The two methods were comparable in quantifying four biofilms colonizing ≥18.7% (R[2] ≥ 0.64), but not for the other biofilms colonizing ≤ 3.7% (R[2] ≤ 0.25). In addition, the two methods exhibited comparable coefficients of variation in the four biofilms. Microscopy and CV staining comparably measured the quantitative variation of biofilms, exhibiting a strongly positive relationship, although microscopy cannot appropriately quantify the biofilms below the threshold colonization. Microscopy with image analysis is a promising approach for easily and rapidly estimating absolute quantity of multispecies biofilms.}, }
@article {pmid36746768, year = {2023}, author = {Williams, DE and Nesbitt, NM and Muralidharan, S and Hossain, S and Boon, EM}, title = {H-NOX Regulates Biofilm Formation in Agrobacterium Vitis in Response to NO.}, journal = {Biochemistry}, volume = {}, number = {}, pages = {}, doi = {10.1021/acs.biochem.2c00639}, pmid = {36746768}, issn = {1520-4995}, abstract = {Transitions between motile and biofilm lifestyles are highly regulated and fundamental to microbial pathogenesis. H-NOX (heme-nitric oxide/oxygen-binding domain) is a key regulator of bacterial communal behaviors, such as biofilm formation. A predicted bifunctional cyclic di-GMP metabolizing enzyme, composed of diguanylate cyclase and phosphodiesterase (PDE) domains (avi_3097), is annotated downstream of an hnoX gene in Agrobacterium vitis S4. Here, we demonstrate that avH-NOX is a nitric oxide (NO)-binding hemoprotein that binds to and regulates the activity of avi_3097 (avHaCE; H-NOX-associated cyclic di-GMP processing enzyme). Kinetic analysis of avHaCE indicates a ∼four-fold increase in PDE activity in the presence of NO-bound avH-NOX. Biofilm analysis with crystal violet staining reveals that low concentrations of NO reduce biofilm growth in the wild-type A. vitis S4 strain, but the mutant ΔhnoX strain has no NO phenotype, suggesting that H-NOX is responsible for the NO biofilm phenotype in A. vitis. Together, these data indicate that avH-NOX enhances cyclic di-GMP degradation to reduce biofilm formation in response to NO in A. vitis.}, }
@article {pmid36744887, year = {2023}, author = {Foote, A and Schutz, K and Zhao, Z and DiGianivittorio, P and Korwin-Mihavics, BR and LiPuma, JJ and Wargo, MJ}, title = {Characterizing Biofilm Interactions between Ralstonia insidiosa and Chryseobacterium gleum.}, journal = {Microbiology spectrum}, volume = {}, number = {}, pages = {e0410522}, doi = {10.1128/spectrum.04105-22}, pmid = {36744887}, issn = {2165-0497}, abstract = {Ralstonia insidiosa and Chryseobacterium gleum are bacterial species commonly found in potable water systems, and these two species contribute to the robustness of biofilm formation in a model six-species community from the International Space Station (ISS) potable water system. Here, we set about characterizing the interaction between these two ISS-derived strains and examining the extent to which this interaction extends to other strains and species in these two genera. The enhanced biofilm formation between the ISS strains of R. insidiosa and C. gleum is robust to starting inoculum and temperature and occurs in some but not all tested growth media, and evidence does not support a soluble mediator or coaggregation mechanism. These findings shed light on the ISS R. insidiosa and C. gleum interaction, though such enhancement is not common between these species based on our examination of other R. insidiosa and C. gleum strains, as well as other species of Ralstonia and Chryseobacterium. Thus, while the findings presented here increase our understanding of the ISS potable water model system, not all our findings are broadly extrapolatable to strains found outside of the ISS. IMPORTANCE Biofilms present in drinking water systems and terminal fixtures are important for human health, pipe corrosion, and water taste. Here, we examine the enhanced biofilm of cocultures for two very common bacteria from potable water systems: Ralstonia insidiosa and Chryseobacterium gleum. While strains originally isolated on the International Space Station show enhanced dual-species biofilm formation, terrestrial strains do not show the same interaction properties. This study contributes to our understanding of these two species in both dual-culture and monoculture biofilm formation.}, }
@article {pmid36744530, year = {2023}, author = {Boddapati, S and Gummadi, SN}, title = {Production and application of purified mutanase from novel Cellulosimicrobium funkei SNG1 in invitro biofilm degradation.}, journal = {Biotechnology and applied biochemistry}, volume = {}, number = {}, pages = {}, doi = {10.1002/bab.2446}, pmid = {36744530}, issn = {1470-8744}, abstract = {Mutanase (α-1-3-glucanase) is an inducible extracellular enzyme with potential medical applications in dentistry. A novel Cellulosimicrobium funkei strain SNG1 producing mutanase enzyme using α-1-3 glucans was isolated and the enzyme was optimized for increased productivity using the one-factor-at-a-time approach. Maximum growth and enzyme-specific activity (2.12 ± 04 U/mg) were attained in a production medium with pH 7.0 and 1% α-1-3 glucans as carbon source, incubated at 37°C for 30 h. The result showed a five-fold increase in activity compared to unoptimized conditions (0.40 U/mg). The enzyme was purified by gel-filtration chromatography and recovered with a yield of 29.03% and a specific activity increase of 10.9-fold. The molecular mass of the monomeric enzyme is 137 kDa. The pH and temperature optima are 6.0 and 45°C with Km of 1.28 ± 0.11 mg for α-1-3 glucans. The enzyme activity was stimulated by adding Co[2+] , Ca[2+] , Cu[2+] and was entirely inhibited by Hg[2+] . On two-hour incubation, the purified enzyme effectively degraded invitro film with an 82.68% degradation rate and a saccharification yield of 30%. This article is protected by copyright. All rights reserved.}, }
@article {pmid36744091, year = {2023}, author = {Lan, S and Chen, X and Yin, C and Xie, S and Wang, S and Deng, R and Shen, Z}, title = {Antibacterial and anti-biofilm activities of Disaspidin BB against Staphylococcus epidermidis.}, journal = {Frontiers in microbiology}, volume = {14}, number = {}, pages = {999449}, pmid = {36744091}, issn = {1664-302X}, abstract = {INTRODUCTION: Staphylococcus epidermidis infections are an important concern in worldwide, especially when associated with biofilms, and resistance of this agent to many drugs makes the situation even worse. We investigated the inhibitory effect of Disaspidin BB obtained from plant extracts and purifications on clinical S. epidermidis strains and their biofilms, and preliminarily investigated its mechanism of of its anti-biofilm activity.<br><br>METHODS AND RESULTS: The broth dilution method was used to determine the minimum inhibitory concentrations (MIC) of Disaspidin BB on 11 clinical S. epidermidis strains (MIC value of 0.63&#x2009;~&#x2009;2.5&#x2009;&#x3bc;g/ml). SEP-05 was found to be erythromycin-resistant (MIC value>8&#x2009;&#x3bc;g/ml) and Disaspidin BB sensitive with an MIC value of 0.63&#x2009;&#x3bc;g/ml. The time-kill curve assay indicated that the antibacterial activity of Disaspidin BB against SEP-05 with concentration dependence. The metabolic activity and total biomass of the drug-treated SEP-05 biofilm in each stage were significantly inhibited by the crystalline violet and XTT assay, and the scavenging effect of Disaspidin BB on SEP-05 biofilm was also confirmed by SEM observation. The results of real-time quantitative PCR showed that subinhibitory concentrations Disaspidin BB can inhibit biofilm formation by affecting the expression level of key genes (aap, atlE, icaA, luxS, recA) in SEP-05 biofilm formation. In addition, the content of polysaccharides, proteins and extracellular DNA in biofilm matrix after the intervention of Disaspidin BB was significantly reduced, and it was tentatively determined that the ability of SEP-05 biofilm formation and its stability were thus disturbed.<br><br>DISCUSSION: The results show that Disaspidin BB has promising antibacterial effect on erythromycin-resistant S. epidermidis and significant scavenging effect on its biofilm, which provides a theoretical basis for the further development of BB as a new drug for the treatment of skin infections caused by S. epidermidis.}, }
@article {pmid36741766, year = {2023}, author = {Tang, Z and Zhang, H and Xiong, J and Li, Y and Luo, W}, title = {Enhanced iturin a production in a two-compartment biofilm reactor by Bacillus velezensis ND.}, journal = {Frontiers in bioengineering and biotechnology}, volume = {11}, number = {}, pages = {1102786}, pmid = {36741766}, issn = {2296-4185}, abstract = {In this study, a two-compartment biofilm reactor was designed for iturin A production. The biofilm reactor consists of a stirred-tank fermentor containing exclusively suspended cells and a packing column where the biofilm is attached. Polyester fiber with sphere shape and rough surfaces was chosen as the carrier of biofilm in packing column. Batch, fed-batch, and repeated-batch fermentation using Bacillus velezensis ND in the biofilm reactor were studied. Compared to conventional suspended cell fermentations, the productivity of iturin A in batch and fed-batch biofilm fermentation were increased by 66.7% and 63.3%, respectively. Maximum itutin A concentration of 6.8 ± 0.1 g/L and productivity of 46.9 ± 0.2 mg/L/h were obtained in fed-batch biofilm fermentation. Repeated-batch fermentation showed high stability, with almost same profile as batch fermentation. After a step-wise temperature control strategy was introduced in the biofilm reactor, productivity of iturin A was increased by 131.9% compared to suspended cell reactor. This superior performance of biofilm reactor confirms that it has great potential in industrial production of iturin A.}, }
@article {pmid36741763, year = {2023}, author = {Winkelhorst, M and Cabau-Peinado, O and Straathof, AJJ and Jourdin, L}, title = {Biomass-specific rates as key performance indicators: A nitrogen balancing method for biofilm-based electrochemical conversion.}, journal = {Frontiers in bioengineering and biotechnology}, volume = {11}, number = {}, pages = {1096086}, pmid = {36741763}, issn = {2296-4185}, abstract = {Microbial electrochemical technologies (METs) employ microorganisms utilizing solid-state electrodes as either electron sink or electron source, such as in microbial electrosynthesis (MES). METs reaction rate is traditionally normalized to the electrode dimensions or to the electrolyte volume, but should also be normalized to biomass amount present in the system at any given time. In biofilm-based systems, a major challenge is to determine the biomass amount in a non-destructive manner, especially in systems operated in continuous mode and using 3D electrodes. We developed a simple method using a nitrogen balance and optical density to determine the amount of microorganisms in biofilm and in suspension at any given time. For four MES reactors converting CO2 to carboxylates, >99% of the biomass was present as biofilm after 69 days of reactor operation. After a lag phase, the biomass-specific growth rate had increased to 0.12-0.16 days[-1]. After 100 days of operation, growth became insignificant. Biomass-specific production rates of carboxylates varied between 0.08-0.37 molC molX [-1]d[-1]. Using biomass-specific rates, one can more effectively assess the performance of MES, identify its limitations, and compare it to other fermentation technologies.}, }
@article {pmid36741169, year = {2023}, author = {Lu, X and Wang, G and Xie, Y and Tang, W and Liu, B and Zhang, J}, title = {Efflux pump inhibitor combined with ofloxacin decreases MRSA biofilm formation by regulating the gene expression of NorA and quorum sensing.}, journal = {RSC advances}, volume = {13}, number = {4}, pages = {2707-2717}, pmid = {36741169}, issn = {2046-2069}, abstract = {Carbonyl cyanide p-nitrophenylhydrazone (2e) displayed a lone or synergistic efficacy against MRSA (RSC Adv., 2020, 10, 17854). In this work, the synergistic mechanism of 2e with ofloxacin was studied. MRSA2858 had potential for biofilm formation, and the value of MBEC of 2e alone was 0.78-1.56 μM, while that of 2e + ofloxacin was 0.39-0.78 μM. 2e combined with ofloxacin showed a synergistic anti-biofilm effect against MRSA. Efflux pump inhibitor 2e can better bind to NorA protein. After MRSA2858 was treated with 2e of 1/2MIC (0.78 μM) and ofloxacin of 1/8MIC (0.097 μM), the transcript levels of efflux genes (norA) and quorum-sensing (QS) regulatory genes (agrA, sarA, icaA, hla) were substantially down-regulated, and alpha-hemolysin (Hla) was inhibited by 99.15%. 2e combined with ofloxacin was more effective than 2e alone in reducing bacterial load in vivo. All in all, efflux pump inhibitor 2e enhanced the bactericidal activities of antibiotics through regulating the gene expression of NorA and QS system.}, }
@article {pmid36739193, year = {2023}, author = {Taira, H and Yaga, M and Nakasone, S and Nishida, K and Yamashiro, T}, title = {Significant removal of bacterial biofilm induced by multiple-Short ranges of electric interventions.}, journal = {Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.jos.2022.12.017}, pmid = {36739193}, issn = {1436-2023}, abstract = {BACKGROUND: Biofilm-related infections are serious problems in the Orthopedics field, and Staphylococcus aureus are the most popular causative agents of bacterial infections associated with arthroplasty. Several studies demonstrated a synergistic effect of the electric intervention (EI) and the antibiotic administration in killing bacteria in biofilm; however, a constant, long-time EI was needed. In the present study, the effective removal of biofilm formed with S. aureus on a titanium ring by multiple times of one minute-EI was observed and described.<br><br>METHODS: A methicillin-sensitive S.&#xa0;aureus clinical isolate was used to form biofilm on a titanium ring. After applying a series of EI with various combinations of the frequencies and timings, the amount and principal components of biofilms were assessed with crystal violet staining, live bacterial cell count, and fluorescence staining with confocal laser scanning microscopy.<br><br>RESULTS: More than 60% biofilm removal was observed in the 2-time EI applied at 24 (1) and 72 (3) h (days) post bacterial exposure (PBE) and in the 3-time EI at 0 (0), 24 (1), and 72 (3) h (days) PBE, or at 24 (1), 48 (2), and 72 (3) h (days) PBE. The live bacterial cell numbers, the proportion of live and dead cells, and the amount of extracellular polysaccharide substances (EPS) of biofilm were similar with or without EI. It was assumed that an excess amount of the biofilm removal shown in the several EI was not attributed to the effect of the electrolysis.<br><br>CONCLUSIONS: The effective removal of biofilm was observed when multiple times 1&#xa0;min EI was applied without any changes in the proportion of live and dead bacteria or the amount of EPS. The mechanisms to explain extra biofilm removal remain to be elucidated.}, }
@article {pmid36738904, year = {2023}, author = {Park, GH and Lee, SY and Lee, JB and Chang, BS and Lee, JK and Um, HS}, title = {Effect of photodynamic therapy according to differences in photosensitizers on Staphylococcus aureus biofilm on titanium.}, journal = {Photodiagnosis and photodynamic therapy}, volume = {}, number = {}, pages = {103317}, doi = {10.1016/j.pdpdt.2023.103317}, pmid = {36738904}, issn = {1873-1597}, abstract = {PURPOSE: This study aimed to evaluate the antimicrobial effect of photodynamic therapy (PDT) against Staphylococcus aureus biofilm on a titanium surface and to compare the differences in the effect of PDT using toluidine blue O (TBO) and methylene blue (MB) as a photosensitizer.<br><br>METHODS: The bacterial strain S. aureus ATCC 25923 was used. Sandblasted and acid-etched (SLA) disks were divided into the following six groups: phosphate buffer saline (PBS), TBO, MB, PBS with laser (PBS&#x202f;+&#x202f;L), TBO with laser (TBO&#x202f;+&#x202f;L), and MB with laser (MB&#x202f;+&#x202f;L). The laser group samples were irradiated by a cold diode laser for 60 s. After treatment, the number of surviving bacteria was calculated by counting the colony-forming units (CFUs) and confocal laser scanning microscopy (CLSM) was applied to observe the bacteria on the disk surface.<br><br>RESULTS: The TBO&#x202f;+&#x202f;L and MB&#x202f;+&#x202f;L groups showed significantly lower CFU/ml than the other groups (p < 0.01). The TBO&#x202f;+&#x202f;L group showed significantly lower CFU/ml than the MB&#x202f;+&#x202f;L group (p&#x202f;=&#x202f;0.032). There was no significant difference between the PBS, TBO, MB, and PBS&#x202f;+&#x202f;L groups. Within the limitations of this in vitro study, PDT with TBO and MB can effectively reduce S. aureus biofilm on SLA titanium surfaces. TBO is more effective than MB as a photosensitizer. PDT with TBO may be applied to the treatment of peri-implant disease in the future.}, }
@article {pmid36738701, year = {2023}, author = {Balasubramanian, N and Pounpandi, P and Varatharaju, G and Shanmugaiah, V and Balakrishnan, K and Thirunarayan, MA}, title = {Distribution of virulence genes and biofilm characterization of human isolates of Streptococcus agalactiae: A pilot study.}, journal = {Colloids and surfaces. B, Biointerfaces}, volume = {223}, number = {}, pages = {113151}, doi = {10.1016/j.colsurfb.2023.113151}, pmid = {36738701}, issn = {1873-4367}, abstract = {This study included 21 newly isolated clinical samples of Streptococcus agalactiae (Group B Streptococcus) screened in patients (six male, fifteen female) from various states of India with different infections (urinary tract infections, blood, pus and eye infections). All isolates were identified as Group B Streptococcus (GBS) using hemolytic properties, serogrouping and MALDI-TOF-MS analysis. Six virulence genes, cfb (100%), cylE (90.4%), lmp (85.7%), bca (71.4%), rib (38%) and bac (4.7%) were detected via polymerase chain reaction (PCR). Distribution studies of these six genes revealed five isolates containing five virulence genes (23.8%), followed by ten isolates containing four virulence genes (47.6%). The twenty GBS isolates selected on the glass surface included non-biofilm producers (n = 6, 30%), weak (n = 11, 55%) and moderate biofilm producers (n = 3, 15%). On the polystyrene surface, weak (n = 4, 20%), moderate (n = 2, 10%) and strong (n = 14, 70%) biofilm producers were detected. Live-dead cell staining revealed that more viable cells accumulated in the S. ag 7420 isolate than in the AH1 isolate. Scanning electron microscope (SEM) biofilm analysis showed S. ag AH1 cells appeared as chain-like structures, whereas the S. ag 7420 isolate biofilm cells appeared as fork-like structures on the glass surface. Biofilm elements were analyzed using Energy Dispersive X-Ray Analysis (EDAX) for both isolates and 13 elements with different orders of composition were found. Thus, virulence gene detection, distribution and biofilm formation by these new clinical isolates suggested the virulent nature of these pathogens, which might cause different levels of disease severity in humans.}, }
@article {pmid36737464, year = {2023}, author = {Doherty, C and Byrne, CV and Baqader, S and El-Chami, C and McBain, AJ and Thomason, HA}, title = {Anti-biofilm effects and healing promotion by silver oxynitrate-based dressings.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {2014}, pmid = {36737464}, issn = {2045-2322}, abstract = {Microbial growth within a wound often manifests as biofilms, which can prevent healing and is difficult to eradicate. Novel silver dressings claim to combat wound infection, but anti-biofilm efficacy and effects on healing independent of infection are often unclear. Using in vitro and in vivo S. aureus and P. aeruginosa biofilm models, we report the efficacy of a dressing which produces Ag[1+] ions; an Ag[1+] dressing containing ethylenediaminetetraacetic acid and benzethonium chloride (Ag[1+]/EDTA/BC), and a dressing containing silver oxynitrate (Ag Oxysalts) which produces Ag[1+], Ag[2+] and Ag[3+] ions, against wound biofilms, and their effects on healing. Ag[1+] dressings had minimal effect on in vitro and murine (C57BL/6j) wound biofilms. In contrast, Ag Oxysalts and Ag[1+]/EDTA/BC dressings significantly reduced viable bacteria within in vitro biofilms and demonstrated a visible reduction in bacteria and EPS components within murine wound biofilms. The dressings had different effects on the healing of biofilm-infected and uninfected wounds, with Ag Oxysalts dressings having a greater beneficial effect on re-epithelialisation, wound size and inflammation than the control treatment and the other silver dressings. The different physicochemical properties of the silver dressings result in varied effects on wound biofilms and healing which should be considered when selecting dressings to treat biofilm-infected wounds.}, }
@article {pmid36736398, year = {2023}, author = {Gabriele, F and Ranaldi, R and Bruno, L and Casieri, C and Rugnini, L and Spreti, N}, title = {Biodeterioration of stone monuments: Studies on the influence of bioreceptivity on cyanobacterial biofilm growth and on the biocidal efficacy of essential oils in natural hydrogel.}, journal = {The Science of the total environment}, volume = {870}, number = {}, pages = {161901}, doi = {10.1016/j.scitotenv.2023.161901}, pmid = {36736398}, issn = {1879-1026}, abstract = {An important field of research is devoted to the development of innovative, sustainable, and safe methodologies to counteract biodeterioration of stone monuments due to the growth of microbial communities. However, besides the biocide's efficacy, it is crucial to consider the features of substrates on which biocides must be applied, to define the so-called bioreceptivity of the lithic faces. In this research five different lithotypes, namely Lecce stone, Travertine, Peperino, Serena stone, and Granite, have been used as substrates for the growth of cyanobacterial biofilms. Open porosity, hygroscopic properties, and roughness parameters have been investigated for each lithotype and correlated to the photosynthetic yields of the biofilms colonizing the different stones to propose an easy method to estimate stone bioreceptivity. Different levels of coverage of the stone surfaces have been accomplished in relation to the typology of lithotypes. To develop innovative restoration methodologies against biodeterioration of stone monuments, a hydrogel-biocide system has been optimized by using a polysaccharide dispersion as a matrix where to embed T. vulgaris essential oil (at 0.25 % or 0.1 %) or its main component thymol (at 0.18 % or 0.07 %). The efficacy and the effect of the innovative biocide have been evaluated combining microscopy, photosynthetic measurements, and colorimetric analyses and both the biocides (with T. vulgaris EO or thymol) showed to be highly effective against the cyanobacterial biofilms for at least six months from the treatment without inducing any significant alteration to the lithic surfaces. The efficacy of thymol alone allows to treat colonized surfaces with a single active ingredient, or at least a mixture thereof, much cheaper and reproducible. The results obtained in this work pave the way to develop a sustainable cleaning protocol to counteract the biodeterioration of stone monuments or historic buildings induced by the presence of phototrophic biofilms that endangered their conservation.}, }
@article {pmid36735239, year = {2023}, author = {Ćirković, I and Pejović, A and Jovićević, M and Brkić, S and Djukić, S and Božić, DD}, title = {Staphylococcal biofilm on wedding rings worn by laboratory workers.}, journal = {Acta microbiologica et immunologica Hungarica}, volume = {}, number = {}, pages = {}, doi = {10.1556/030.2023.01919}, pmid = {36735239}, issn = {1588-2640}, abstract = {Hands of healthcare workers play essential role in the spreading of antimicrobial-resistant microorganisms in and out of the healthcare settings. Less is known about the role of laboratory workers (LWs). The aim of our study was to evaluate the presence of biofilm-forming staphylococci on the surface of jewelry rings of LWs and their antimicrobial susceptibility pattern.A total of 79 LWs from eight different microbiology laboratories that process and analyze specimens from the tertiary care hospitals in Belgrade, Serbia participated in the study. The study was reviewed and approved by the institutional review boards at hospitals. Samples were taken after hand washing. Bacteria on LWs wedding rings were detected with the rolling method, and further analyzed in order to determine the number of colony forming unit (CFU) per ring, species of bacteria and their antimicrobial susceptibility pattern, methicillin resistance and biofilm-producing capacity in vitro.Staphylococci were recovered from 60.8% of wedding rings. All strains produced biofilm (25% weak, 56.2% moderate and 18.8% large amount), with significant difference between species (P < 0.001). Staphylococcus aureus and Staphylococcus epidermidis formed the largest amount of biofilm and had the largest number of CFU per ring. Staphylococci were most commonly resistant to penicillin (66.7%), tetracycline (50.0%), and erythromycin (45.8%); 41.7% of isolates was multidrug resistant and mecA gene was detected in five strains. All strains were susceptible to linezolid, vancomycin, teicoplanin and tigecycline.Staphylococci colonize LWs wedding rings, form biofilm on it, have multidrug resistant phenotype and/or carry mecA gene, representing a significant reservoir for the spreading of microorganisms and resistance. As far as we know, our study is the first that address this topic in laboratory workers.}, }
@article {pmid36732890, year = {2023}, author = {Maric, T and Løvind, A and Zhang, Z and Geng, J and Boisen, A}, title = {Near Infrared Light-Driven Mesoporous SiO2 /Au Nanomotors for Eradication of Pseudomonas Aeruginosa Biofilm.}, journal = {Advanced healthcare materials}, volume = {}, number = {}, pages = {e2203018}, doi = {10.1002/adhm.202203018}, pmid = {36732890}, issn = {2192-2659}, abstract = {Bacterial biofilms are linked to several diseases and cause resistant and chronic infections in immune-compromised patients. Due to their ability to overcome, adapt and survive antibacterial treatment, biofilms pose enormous economic consequences. Nanomotors are a new field of research showing a great promise within biomedicine but pose challenges in terms of biocompatibility. Nanomotors propelled by thermophoresis could overcome this challenge, as they leave no waste product during propulsion. In this study, mesoporous-silica nanoparticles were coated with a thin layer of gold to make nanomotors, which could be driven by NIR light irradiation. The prepared mesoporous SiO2 -Au nanomotors exhibit efficient self-propulsion when exposed to NIR irradiation, they penetrate deep through a biofilm matrix and disperse the biofilm in situ due to the photothermal effect on the Au part of the nanomotors. The velocities of such nanomotors are investigated at different wavelengths and laser powers. Furthermore, the study examine the ability of these nanomotors to eradicate Pseudomonas aeruginosa biofilm under NIR light irradiation. The conducted study shows that the nanomotors velocity depends on the intensity of the light and that it increases with increasing laser power. The mesoporous SiO2 /Au nanomotors show excellent capabilities to eradicate Pseudomonas aeruginosa biofilms even under short (30 seconds - 3 minutes) irradiation time. This study shows great promise for overcoming the challenges related to bacterial biofilm eradication. This article is protected by copyright. All rights reserved.}, }
@article {pmid36732330, year = {2023}, author = {Razvi, E and Whitfield, GB and Reichhardt, C and Dreifus, JE and Willis, AR and Gluscencova, OB and Gloag, ES and Awad, TS and Rich, JD and da Silva, DP and Bond, W and Le Mauff, F and Sheppard, DC and Hatton, BD and Stoodley, P and Reinke, AW and Boulianne, GL and Wozniak, DJ and Harrison, JJ and Parsek, MR and Howell, PL}, title = {Glycoside hydrolase processing of the Pel polysaccharide alters biofilm biomechanics and Pseudomonas aeruginosa virulence.}, journal = {NPJ biofilms and microbiomes}, volume = {9}, number = {1}, pages = {7}, doi = {10.1038/s41522-023-00375-7}, pmid = {36732330}, issn = {2055-5008}, abstract = {Pel exopolysaccharide biosynthetic loci are phylogenetically widespread biofilm matrix determinants in bacteria. In Pseudomonas aeruginosa, Pel is crucial for cell-to-cell interactions and reducing susceptibility to antibiotic and mucolytic treatments. While genes encoding glycoside hydrolases have long been linked to biofilm exopolysaccharide biosynthesis, their physiological role in biofilm development is unclear. Here we demonstrate that the glycoside hydrolase activity of P. aeruginosa PelA decreases adherent biofilm biomass and is responsible for generating the low molecular weight secreted form of the Pel exopolysaccharide. We show that the generation of secreted Pel contributes to the biomechanical properties of the biofilm and decreases the virulence of P. aeruginosa in Caenorhabditis elegans and Drosophila melanogaster. Our results reveal that glycoside hydrolases found in exopolysaccharide biosynthetic systems can help shape the soft matter attributes of a biofilm and propose that secreted matrix components be referred to as matrix associated to better reflect their influence.}, }
@article {pmid36731617, year = {2023}, author = {Wang, Q and Pan, Y and Chu, G and Lu, S and Zhang, Z and Zhao, Y and Jin, C and Gao, M}, title = {Impact of aerobic/anoxic alternation number on performance, microbial community and functional genes of sequencing batch biofilm reactor treating mariculture wastewater.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {128699}, doi = {10.1016/j.biortech.2023.128699}, pmid = {36731617}, issn = {1873-2976}, abstract = {The performance, microbial community and functional genes of a sequencing batch biofilm reactor (SBBR) were investigated in treating mariculture wastewater under different aerobic/anoxic alternation number. The removal efficiency of chemical oxygen demand (COD) and NH4[+]-N kept at 95.66 ± 1.83% and 90.28 ± 2.42% under aerobic/anoxic alternation number between 1 and 4. The total nitrogen (TN) removal efficiency gradually decreased from 94.45 ± 1.12% to 83.06 ± 1.25% with increase of aerobic/anoxic alternative number from 1 to 4. The nitrification rates and their corresponding enzymatic activities increased slightly with increase of aerobic/anoxic alternation number, whereas the denitrifying process had the contrary results. The variation of aerobic/anoxic alternation number obviously affected the microbial diversity and abundance. The microbial network structure and keystone taxa of SBBR were different under different aerobic/anoxic alternation number. The functional genes abundance for the denitrification pathway decreased with the increase of aerobic/anoxic alternation number.}, }
@article {pmid36731122, year = {2023}, author = {Dzofou Ngoumelah, D and Kuchenbuch, A and Harnisch, F and Kretzschmar, J}, title = {Combining Geobacter spp. Dominated Biofilms and Anaerobic Digestion Effluents─The Effect of Effluent Composition and Electrode Potential on Biofilm Activity and Stability.}, journal = {Environmental science &amp; technology}, volume = {}, number = {}, pages = {}, doi = {10.1021/acs.est.2c07574}, pmid = {36731122}, issn = {1520-5851}, abstract = {The combination of anaerobic digestion (AD) and microbial electrochemical technologies (METs) offers different opportunities to increase the efficiency and sustainability of AD processes. However, methanogenic archaea and/or particles may partially hinder combining MET and AD processes. Furthermore, it is unclear if the applied anode potential affects the activity and efficiency of electroactive microorganisms in AD-MET combinations as it is described for more controlled experimental conditions. In this study, we confirm that 6-week-old Geobacter spp. dominated biofilms are by far more active and stable in AD-effluents than 3-week-old Geobacter spp. dominated biofilms. Furthermore, we show that the biofilms are twice as active at -0.2 V compared to 0.4 V, even under challenging conditions occurring in AD-MET systems. Paired-end amplicon sequencing at the DNA level using 16S-rRNA and mcrA gene shows that hydrogenotrophic methanogens incorporate into biofilms immersed in AD-effluent without any negative effect on biofilm stability and electrochemical activity.}, }
@article {pmid36730195, year = {2023}, author = {Platt, TG}, title = {Community outcomes depend on cooperative biofilm structure.}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {120}, number = {6}, pages = {e2221624120}, doi = {10.1073/pnas.2221624120}, pmid = {36730195}, issn = {1091-6490}, }
@article {pmid36724854, year = {2023}, author = {Zhou, W and Niu, D and Gao, S and Zhong, Q and Liu, C and Liao, X and Cao, X and Zhang, Z and Zhang, Y and Shen, H}, title = {Prevalence, biofilm formation, and mass spectrometric characterization of linezolid-resistant Staphylococcus capitis isolated from a tertiary hospital in China.}, journal = {Journal of global antimicrobial resistance}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.jgar.2023.01.005}, pmid = {36724854}, issn = {2213-7173}, abstract = {BACKGROUND: Linezolid-resistant Staphylococcus capitis (LRSC) has become a new challenge for clinical anti-infective therapy. The present study aims to investigate the trends of LRSC prevalence in a tertiary hospital of China 2017-2020, and the resistance mechanism, virulence genes, biofilm formation, and mass spectrometric characteristics of LRSC isolated were also analyzed.<br><br>METHODS: This study retrospectively analyzes the antibiotic resistance trends of CoNS isolated from clinical samples collected between 2017 and 2020. Antimicrobial resistance profile were tested by micro-broth dilution and E-test method. Antimicrobial resistance genes and virulence genes were detected by PCR, and dru-typing sequences were obtained by Sanger sequencing. Crystal violet staining in 96-well plates was used to detect biofilm formation ability. Mass spectrometric characterization of LRSC was analyzed by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) coupled with ClinProTools.<br><br>RESULTS: The linezolid resistance rate in 3,575 Coagulase-negative staphylococci (CoNS) clinical strains was 1.6%, wherein the great majority of was LRSC (91.1%, n&#x202f;=&#x202f;51/56), with a resistant rate of 15.5% (n&#x202f;=&#x202f;51/328) in all S. capitis isolates. In this study, 48 out of the 51 LRSC strains and 54 out of 277 linezolid-susceptible S. capitis (LSSC) strains were enrolled. G2576T, C2104T, T2130A, C2163T and T2319C mutations in the 23S rRNA V region and acquisition of cfr was the main linezolid resistant mechanism in LRSC. The biofilm-forming ability of LRSC was more potent than LSSC, with a higher detection rate of bap (P < 0.05). Eleven mass spectrometric peaks of interest were identified by using MALDI-TOF MS and ClinProTools which were differently distributed between LRSC and LSSC strains with the area under the receiver operating characteristic curve of more than 0.8, especially for 5465.37 m/z.<br><br>CONCLUSIONS: Linezolid resistance was mediated by mutations in the 23S rRNA V region and presence of the cfr gene in LRSC strains. LRSC strains have stronger biofilm-forming ability than linezolid-susceptible strains, which maybe associated with the adhesion-related gene of bap. Further, linezolid-resistant and linezolid-susceptible S. capitis could be rapidly identified with mass spectrometric characterization. To the best of our knowledge, this study is the first to document the biofilm formation ability of LRSC and the potential usefulness of MALDI-TOF MS for the discrimination of LRSC and LSSC.}, }
@article {pmid36723506, year = {2023}, author = {Fathi-Hafshejani, P and Tinker, HB and Freel, K and Mahjouri-Samani, M and Hasim, S}, title = {Effects of TiS2 on Inhibiting Candida albicans Biofilm Formation and Its Compatibility with Human Gingival Fibroblasts in Titanium Implants.}, journal = {ACS applied bio materials}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsabm.2c00707}, pmid = {36723506}, issn = {2576-6422}, abstract = {Titanium is widely used in medical devices, such as dental and orthopedic implants, due to its excellent mechanical properties, low toxicity, and biocompatibility. However, the titanium surface has the risk of microbial biofilm formation, which results in infections from species such as Candida albicans (C. albicans). This kind of biofilm prevents antifungal therapy and complicates the treatment of infectious diseases associated with implanted devices. It is critical to developing a feasible surface to decrease microbial growth while not interfering with the growth of the host cells. This study reports the influence of titanium surface modification to titanium disulfide (TiS2) on inhibiting C. albicans biofilm formation while allowing the attachment of human gingival fibroblasts (HGFs) on their surface. The surface of titanium parts is directly converted to structured titanium and TiS2 using direct laser processing and crystal growth methods. C. albicans adhesion and colonization are then investigated on these surfaces by the colony counting assay and reactive oxygen species (ROS) assay, using 2',7'-dichlorofluorescin diacetate (DCFH-DA) and microscopy images. Also, the viability and adhesion of HGFs on these surfaces are investigated to show their adhesion and biocompatibility. Titanium samples with the TiS2 surface show both C. albicans biofilm inhibition and HGF attachment. This study provides insight into designing and manufacturing titanium biomedical implants.}, }
@article {pmid36722674, year = {2023}, author = {Kraft, L and Ribeiro, VST and Petroski, LP and Herai, RH and Peronni, KC and Figueiredo, DLA and Motta, FA and Tuon, FF}, title = {Saprochaete clavata invasive infection: characterization, antifungal susceptibility, and biofilm evaluation of a rare yeast isolated in Brazil.}, journal = {Revista do Instituto de Medicina Tropical de Sao Paulo}, volume = {65}, number = {}, pages = {e12}, doi = {10.1590/S1678-9946202365012}, pmid = {36722674}, issn = {1678-9946}, abstract = {Rare emerging pathogens such as Saprochaete clavata are associated with invasive fungal diseases, high morbidity, mortality, rapidly fatal infections, and outbreaks. However, little is known about S. clavata infections, epidemiology, risk factors, treatment, biofilms, and disease outcomes. The objective of this study was to describe a new case of severe S. clavata infection in a patient diagnosed at a referral children's hospital in Brazil, including antifungal minimal inhibitory concentration, S. clavata biofilm characterization, and molecular characterization. The S. clavata isolated from an immunocompromised 11-year-old male patient was characterized using MALDI-TOF, Gram staining, scanning electron microscopy (SEM), and next generation sequencing (NGS) of genomic DNA. Biofilm production was also evaluated in parallel with determining minimal inhibitory concentration (MIC) and biofilm sensitivity to antifungal treatment. We observed small to medium, whitish, farinose, dry, filamentous margin colonies, yeast-like cells with bacillary features, and biofilm formation. The MALDI-TOF system yielded a score of ≥ 2,000, while NGS confirmed S. clavata presence at the nucleotide level. The MIC values (in mg L-1) for tested drugs were as follows: fluconazole = 2, voriconazole ≤ 2, caspofungin ≥ 8, micafungin = 2, amphotericin B = 4, flucytosine ≤ 1, and anidulafungin = 1. Amphotericin B can be active against S. clavata biofilm and the fungus can be susceptible to new azoles. These findings were helpful for understanding the development of novel treatments for S. clavata-induced disease, including combined therapy for biofilm-associated infections.}, }
@article {pmid36721500, year = {2022}, author = {Rezania, N and Rahmati, P and Noorbakhsh, F and Farhadyar, N and Lotfali, E}, title = {Investigation the effects of silver nanoparticles and gold nanoparticles on expression of bap and csu genes in biofilm formation of Acinetobacter baumannii.}, journal = {Iranian journal of microbiology}, volume = {14}, number = {4}, pages = {510-517}, pmid = {36721500}, issn = {2008-3289}, abstract = {BACKGROUND AND OBJECTIVES: Acinetobacter baumannii is one of the main pathogens of the hospital and causes various infections. csu A/BABCDE involved in the initial surface attachment during biofilm formation and bap gene produces specific proteins at the cell surface that play a direct role in formation of biofilm and the infectivity of this bacterium. The aim of this study was to investigate the effect of silver nanoparticles and gold nanoparticles on the expression of bap and csu genes in the Acinetobacter baumannii biofilm formation.<br><br>MATERIALS AND METHODS: The susceptibility test was performed to determine the MIC of silver nanoparticles, gold nanoparticles and gold-vancomycin nanoparticles performed by broth dilution method on A. baumannii strains. The ability of biofilms formation in strains treated by MIC of silver nanoparticles and gold-vancomycin nanoparticles were evaluated by microtiter plate method and A. baumannii ATCC19606 used as control. Expression of the csu and bap genes were determinded by measuring the cognate mRNA level by real-time PCR.<br><br>RESULTS: In present study, gold nanoparticles could not prevent the growth and biofilm formation of A. baumannii strains. The MIC concentration of silver nanoparticles and vancomycin- gold nanoparticles were 6.25 &#x3bc;g/ml and 0.625 &#x3bc;g/ml respectively and MBC concenteration of nanoparticles for 70% of strain was 12.5 &#x3bc;g/ml and 1.25 &#x3bc;g/ml respectively. Real-time PCR and data analysis, determined that the expression of bap, csuC and csuE genes in A. baumannii strains treated with MIC concentration (6.25 &#x3bc;g/ml) of silver nanoparticles decreased compared to control groups. Also, the expression of csuC and csuE genes in strains treated with MIC concentration (0.625 &#x3bc;g/ml) of vancomycin -gold nanoparticles increased, however the expression of bap was decreased compared to the control groups.<br><br>CONCLUSION: Due to the inhibitory effect of silver nanoparticles and gold-vancomycin nanoparticles against A. baumannii biofilm formation and genes expression, they can probably be used for prevent of biofilm formation in medical instrument or can be use for treatment of infections with or without antibiotic.}, }
@article {pmid36721488, year = {2022}, author = {Kanagasingam, S and von Ruhland, C and Welbury, R and Singhrao, SK}, title = {Ex vivo Detection of Amyloid-β in Naturally Formed Oral Biofilm.}, journal = {Journal of Alzheimer's disease reports}, volume = {6}, number = {1}, pages = {757-773}, pmid = {36721488}, issn = {2542-4823}, abstract = {BACKGROUND: Oral infection has been implicated in the possible etiology of Alzheimer's disease.<br><br>OBJECTIVE: To detect amyloid-&#x3b2; (A&#x3b2;) within microbial biofilms.<br><br>METHODS: Freshly extracted teeth (N&#x200a;=&#x200a;87) with periodontal disease were separated into Group A (N&#x200a;=&#x200a;11), with primary root canal infection and Group B (N&#x200a;=&#x200a;21) with failed endodontic treatment identified by the presence of, gutta percha root filling. Biofilm characteristics were observed by scanning electron microscopy (SEM). Demineralized paraffin wax embedded tooth sections and mineralized calculus biofilm were immunostained with the anti-A&#x3b2; antibody. The gutta perchas were processed either for on-section acrylic resin tissue immunocolloidal gold silver staining (IGSS) using the anti-A&#x3b2; antibody or in Araldite resin for ultrastructure.<br><br>RESULTS: SEM demonstrated calculus and gutta percha in situ harboring a polymicrobial biofilm featuring extracellular polymeric substance (EPS) and water channels. Immunohistochemistry on rehydrated paraffin wax tooth sections from Group A, demonstrated A&#x3b2; staining on external (calculus and plaque) and all intracanal infected regions. In Group B, the gutta percha biofilm IGSS gave an inconclusive result for A&#x3b2;. Transmission electron microscopy of selected teeth with infected intra-canals (Group A) and 20% of gutta percha biofilm (Group B) EPS contained electron dense fibrils of variable sizes, some of which were typical of human A&#x3b2; fibrils.<br><br>CONCLUSION: This study detected both soluble and insoluble A&#x3b2; fibrils within the EPS of periodontal and endodontic natural biofilm, strongly suggesting its role as an antimicrobial peptide in combatting local infection, with potential risk for cross-seeding into the brain for AD development.}, }
@article {pmid36721451, year = {2022}, author = {Sabzi, N and Moniri, R and Sehat, M and Fathizadeh, H and Nazari-Alam, A}, title = {Antimicrobial effect of silver and gold nanoparticles in combination with linezolid on Enterococcus biofilm.}, journal = {Iranian journal of microbiology}, volume = {14}, number = {6}, pages = {863-873}, pmid = {36721451}, issn = {2008-3289}, abstract = {BACKGROUND AND OBJECTIVES: In the past few years, application of new antimicrobial e.g. nanoparticles (NPs) to treat infection caused by drug-resistant bacteria has increased. This study aimed to determine antimicrobial property of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) in combination with linezolid on Enterococcus biofilm.<br><br>MATERIALS AND METHODS: A total of forty-eight isolates of Enterococcus spp. were collected and confirmed by PCR method. The synthesis of biocompatible AgNPs was performed, then analyzed by Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy. We carried out minimum inhibitory concentration (MIC) and biofilm forming capacity of AgNPs and AuNPs with linezolid.<br><br>RESULTS: Twenty-two E. faecium isolates and twentysix E. faecalis investigated in this study. Strong biofilm formation was seen in 12 (25%) of isolates, and others isolates (75%) formed moderate biofilm. AgNPs and Au-NPs size were 26 nm and 20 nm respectively. The MIC of AgNPs was 23.2 &#x3bc;g/ml, and AuNPs were 92.1 &#x3bc;g/ml and the lowest MIC was obtained 2 &#x3bc;g/ml in linezolid. Biofilm formation inhibitory activity by AuNPs + Linezolide and AgNPs + Linezolide 70 to 80 percent increased in average.<br><br>CONCLUSION: The antibiofilm activity of AgNPs and AuNPs increased when both agents were used in combination with linezolid in comparison with each agent alone.}, }
@article {pmid36721450, year = {2022}, author = {Mahmoud, S and Gaber, Y and Khattab, RA and Bakeer, W and Dishisha, T and Ramadan, MA}, title = {The inhibitory effect of dextranases from Bacillus velezensis and Pseudomonas stutzeri on Streptococcus mutans biofilm.}, journal = {Iranian journal of microbiology}, volume = {14}, number = {6}, pages = {850-862}, pmid = {36721450}, issn = {2008-3289}, abstract = {BACKGROUND AND OBJECTIVES: Dental caries is a breakdown of the teeth enamel due to harmful bacteria, lack of oral hygiene, and sugar consumption. The acid-producing bacterium Streptococcus mutans is the leading cause of dental caries. Dextranase is an enzyme that can degrade dextran to low molecular weight fractions, which have many therapeutic and industrial applications. The purpose of the present study was to isolate a novel dextranase-producing bacteria from a source (molasses). The cell-free extracts containing dextranases were tested as antibiofilm agents.<br><br>MATERIALS AND METHODS: Dextranase-producing bacteria were identified using phenotypic and genotypic methods such as 16S rRNA gene sequencing and enzymatic characterization.<br><br>RESULTS: The highest six dextranase-producing bacterial isolates were Bacillus species. The best conditions for dextranase productivity were obtained after 72 hours of culture time at pH 7. The addition of glucose to the medium enhanced the production of the enzymes. The cell-free extract of the six most active isolates showed remarkable activity against biofilm formation by Streptococcus mutans ATCC 25175. The highest inhibition activities reached 60% and 80% for Bacillus velezensis and Pseudomonas stutzeri, respectively.<br><br>CONCLUSION: Therefore, our study added to the current dextranase-producing bacteria with potential as a source of dextranases.}, }
@article {pmid36720360, year = {2023}, author = {Afrasiabi, S and Chiniforush, N}, title = {An in vitro study on the efficacy of hydrogen peroxide mediated high-power photodynamic therapy affecting Enterococcus faecalis biofilm formation and dispersal.}, journal = {Photodiagnosis and photodynamic therapy}, volume = {}, number = {}, pages = {103310}, doi = {10.1016/j.pdpdt.2023.103310}, pmid = {36720360}, issn = {1873-1597}, abstract = {OBJECTIVE: Biofilms are involved in failure of root canal treatment due to their high resistance to antimicrobial agents, which make their removal as a big challenge. The present study aims at utilizing hydrogen peroxide (HP) plus high frequency laser reinforced antimicrobial photodynamic therapy (a-PDT) as a complementary therapy against Enterococcus faecalis (E. faecalis) at planktonic and biofilm stages.<br><br>MATERIALS AND METHODS: E. faecalis at&#xa0;planktonic&#xa0;and&#xa0;biofilm&#xa0;stages was treated with the photosensitizer HP, followed by no irradiation or irradiation with a power of 2.5 W (&#x28e;&#x202f;=&#x202f;980 nm). The cell viability, anti-biofilm, anti-metabolic potential, and temperature changes were evaluated.<br><br>RESULTS: The combination of HP and 980 nm diode laser intensely boosted antibacterial and anti-biofilm efficacy compared with either component alone, affirming HP reinforcement as a bacteriostatic agent. The maximum effect on biofilm occurs in 5.25%&#xa0;sodium&#xa0;hypochlorite (NaOCl) group. During laser irradiations, the mean of temperature changes remains below 5.6&#xb0;C.<br><br>CONCLUSIONS: It could be concluded that the HP could improve anti-biofilm efficacy as a photosensitizer in a-PDT.}, }
@article {pmid36719505, year = {2023}, author = {Chew, RJJ and Tang, YL and Lin, XYS and Oh, FJB and Sim, RP and Anwar, EJ and Preshaw, PM and Tan, KS}, title = {Toll-like receptor-4 activation by subgingival biofilm and periodontal treatment response.}, journal = {Clinical oral investigations}, volume = {}, number = {}, pages = {}, pmid = {36719505}, issn = {1436-3771}, abstract = {OBJECTIVES: This study aims to investigate longitudinally the activation of Toll-like receptor-4 (TLR-4) by subgingival biofilm samples before and after nonsurgical periodontal therapy (NSPT).<br><br>MATERIALS AND METHODS: Forty periodontitis patients received NSPT and were reviewed 3 and 6 months post-treatment. Subgingival biofilm was sampled from 4 teeth per patient, at baseline and each follow-up time point. TLR-4 activation was determined using the HEK-BLUE&#x2122;/hTLR4 system. Changes in TLR-4 activation and probing pocket depths (PPDs) were evaluated using generalised linear models, and the association between TLR-4 activation and pocket reduction (defined as 6-month PPDs &#x2264; 3mm) was determined using generalised estimating equations.<br><br>RESULTS: At 6 months, the mean TLR-4 activation by subgingival biofilm samples was significantly reduced from 11.2AU (95%CI 7.1AU, 15.4AU) to 3.6AU (95%CI 2.3AU, 4.8AU, p < 0.001), paralleling significant reductions in mean PPDs at sampled sites. The response to NSPT was associated with longitudinal TLR-4 activation profiles, with significantly higher TLR-4 activation by subgingival biofilm obtained from sites that did not achieve pocket reduction, compared to sites at which pocket reduction was achieved.<br><br>CONCLUSIONS: The activation of TLR-4 by subgingival biofilm samples was reduced after NSPT, and this reduction was significantly associated with the clinical improvements (PPD reductions) at sampled sites.<br><br>CLINICAL RELEVANCE: This study demonstrated an association between the longitudinal profile of TLR-4 activation by subgingival biofilm and periodontal treatment response. Longitudinal monitoring of TLR-4 activation by subgingival biofilm may potentially identify non-responsive sites, enabling targeted additional treatment.}, }
@article {pmid36716948, year = {2023}, author = {Rozman, U and Filker, S and Kalčíková, G}, title = {Monitoring of biofilm development and physico-chemical changes of floating microplastics at the air-water interface.}, journal = {Environmental pollution (Barking, Essex : 1987)}, volume = {}, number = {}, pages = {121157}, doi = {10.1016/j.envpol.2023.121157}, pmid = {36716948}, issn = {1873-6424}, abstract = {Microplastics in aquatic environments serve as habitat for microbial life, on which they can form biofilms. However, how the development of the biofilm alters the properties of floating microplastics that are at the air-water interface and, therefore, not fully submerged, is not well understood. In this context, an aging experiment was conducted to monitor biofilm formation and changes in physico-chemical properties of low-density polyethylene (floating) microplastics over time. The growth of the biofilm followed the typical bacterial/biofilm growth phases and reached about 30% of the total mass of the microplastics, while the concentration of extracellular polymeric substances within the biofilm remained stable. Presence of chlorophyll a and urease activity indicated presence of photosynthetic organisms within the biofilm which was also confirmed by analysis of the biofilm composition. Chemical characterization by FTIR showed the formation of additional functional groups attributed to the formed biofilm, and SEM imaging showed cracks on the surface of the aged microplastics, indicating incipient degradation of the polyethylene. Moreover, the adsorption capacity of the aged particles for metals (Pb(II)) was 52% higher compared to the pristine ones. Aging increased the density and size of the particles; however, it did not lead to the submersion of the aged particles even after 12 weeks of aging, suggesting that additional environmental processes may influence the transport of microplastics from the air-water interface into the water body.}, }
@article {pmid36716932, year = {2023}, author = {Win Thant, KJ and Anh-Vu, N and Yun-Je, K and Masumi, K and Visvanathan, C}, title = {Performance of pilot-scale membrane aerated biofilm reactors integrated with anoxic nano-biotechnological reactor for domestic wastewater treatment.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {137927}, doi = {10.1016/j.chemosphere.2023.137927}, pmid = {36716932}, issn = {1879-1298}, abstract = {Membrane-aerated biofilm reactors (MABRs) have aroused increasing attention due to their excellent performance in treating wastewater, where the membranes behave as bio-carriers for microorganisms and bubbleless air diffusers. The MABR technology has not been fully commercialized due to reactor design and low total nitrogen (TN) removal efficiency at short hydraulic retention times (HRT). In this study, a hybrid system of MABR 1 integrated with an anoxic nano-biotechnological reactor filled with Granulated Nanoscale Oxyhydroxides of Iron (GNOF) media was evaluated to assess the improvement in nitrogen removal performance at 12, 10, and 4 h of HRTs. At the same time, another MABR (MABR 2) was operated individually at 12, 10, 8, 6, 4, and 2 h of HRTs to assess the influence of HRT on nitrogen removal performance. An enhancement in removal performance was reported in the hybrid MABR + GNOF, achieving the highest removal efficiencies of 74.3 ± 3.1% for ammonia nitrogen (NH4[+]-N), 69.8 ± 2.1% for total nitrogen (TN), and 90.9 ± 1.7% for chemical oxygen demand (COD), at 12 h HRT. The performance of the hybrid MABR-GNOF system was 18% higher nitrogen removal than the MABR-only system at 12 h of HRT. A simultaneous anoxic nitrification-denitrification and COD oxidation might be developed for the removal of COD, NH4[+]-N, and TN from domestic wastewater by using GNOF as an electron acceptor in the hybrid MABR-GNOF unit. The findings in this study confirmed the possibility of integration of GNOF and MABR on a pilot scale and are promising for the application of this hybrid system on a full scale.}, }
@article {pmid36716802, year = {2023}, author = {Rawindran, H and Syed, R and Alangari, A and Khoo, KS and Lim, JW and Sahrin, NT and Suparmaniam, U and Raksasat, R and Liew, CS and Leong, WH and Kiatkittipong, W and Shahid, MK and Hara, H and Shaharun, MS}, title = {Mechanistic behaviour of Chlorella vulgaris biofilm formation onto waste organic solid support used to treat palm kernel expeller in the recent Anthropocene.}, journal = {Environmental research}, volume = {}, number = {}, pages = {115352}, doi = {10.1016/j.envres.2023.115352}, pmid = {36716802}, issn = {1096-0953}, abstract = {The capacity to maximize the proliferation of microalgal cells by means of topologically textured organic solid surfaces under various pH gave rise to the fundamental biophysical analysis of cell-surface attachment in this study. The substrate used in analysis was palm kernel expeller (PKE) in which the microalgal cells had adhered onto its surface. The findings elucidated the relevance of surface properties in terms of surface wettability and surface energy in relation to the attached microalgal growth with pH as the limiting factor. The increase in hydrophobicity of PKE-microalgae attachment was able to facilitate the formation of biofilm better. The pH 5 and pH 11 were found to be the conditions with highest and lowest microalgal growths, respectively, which were in tandem with the highest contact angle value at pH 5 and conversely for pH 11. The work of attachment (Wcs) had supported the derived model with positive values being attained for all the pH conditions, corroborating the thermodynamic feasibility. Finally, this study had unveiled the mechanism of microalgal attachment onto the surface of PKE using the aid of extracellular polymeric surfaces (EPS) from microalgae. Also, the hydrophobic nature of PKE enabled excellent attachment alongside with nutrients for microalgae to grow and from layer-by-layer (LbL) assembly. This assembly was then isolated using organosolv method by means of biphasic solvents, namely, methanol and chloroform, to induce detachment.}, }
@article {pmid36714834, year = {2022}, author = {Velsko, IM and Semerau, L and Inskip, SA and García-Collado, MI and Ziesemer, K and Ruber, MS and Benítez de Lugo Enrich, L and Molero García, JM and Valle, DG and Peña Ruiz, AC and Salazar-García, DC and Hoogland, MLP and Warinner, C}, title = {Ancient dental calculus preserves signatures of biofilm succession and interindividual variation independent of dental pathology.}, journal = {PNAS nexus}, volume = {1}, number = {4}, pages = {pgac148}, pmid = {36714834}, issn = {2752-6542}, abstract = {Dental calculus preserves oral microbes, enabling comparative studies of the oral microbiome and health through time. However, small sample sizes and limited dental health metadata have hindered health-focused investigations to date. Here, we investigate the relationship between tobacco pipe smoking and dental calculus microbiomes. Dental calculus from 75 individuals from the 19th century Middenbeemster skeletal collection (Netherlands) were analyzed by metagenomics. Demographic and dental health parameters were systematically recorded, including the presence/number of pipe notches. Comparative data sets from European populations before and after the introduction of tobacco were also analyzed. Calculus species profiles were compared with oral pathology to examine associations between microbiome community, smoking behavior, and oral health status. The Middenbeemster individuals exhibited relatively poor oral health, with a high prevalence of periodontal disease, caries, heavy calculus deposits, and antemortem tooth loss. No associations between pipe notches and dental pathologies, or microbial species composition, were found. Calculus samples before and after the introduction of tobacco showed highly similar species profiles. Observed interindividual microbiome differences were consistent with previously described variation in human populations from the Upper Paleolithic to the present. Dental calculus may not preserve microbial indicators of health and disease status as distinctly as dental plaque.}, }
@article {pmid36713201, year = {2022}, author = {Guevara-Lora, I and Bras, G and Juszczak, M and Karkowska-Kuleta, J and Gorecki, A and Manrique-Moreno, M and Dymek, J and Pyza, E and Kozik, A and Rapala-Kozik, M}, title = {Cecropin D-derived synthetic peptides in the fight against Candida albicans cell filamentation and biofilm formation.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1045984}, pmid = {36713201}, issn = {1664-302X}, abstract = {The recent progressive increase in the incidence of invasive fungal infections, especially in immunocompromised patients, makes the search for new therapies crucial in the face of the growing drug resistance of prevalent nosocomial yeast strains. The latest research focuses on the active compounds of natural origin, inhibiting fungal growth, and preventing the formation of fungal biofilms. Antimicrobial peptides are currently the subject of numerous studies concerning effective antifungal therapy. In the present study, the antifungal properties of two synthetic peptides (ΔM3, ΔM4) derived from an insect antimicrobial peptide - cecropin D - were investigated. The fungicidal activity of both compounds was demonstrated against the yeast forms of Candida albicans, Candida tropicalis, and Candida parapsilosis, reaching a MFC99.9 in the micromolar range, while Candida glabrata showed greater resistance to these peptides. The scanning electron microscopy revealed a destabilization of the yeast cell walls upon treatment with both peptides; however, their effectiveness was strongly modified by the presence of salt or plasma in the yeast environment. The transition of C. albicans cells from yeast to filamentous form, as well as the formation of biofilms, was effectively reduced by ΔM4. Mature biofilm viability was inhibited by a higher concentration of this peptide and was accompanied by increased ROS production, activation of the GPX3 and SOD5 genes, and finally, increased membrane permeability. Furthermore, both peptides showed a synergistic effect with caspofungin in inhibiting the metabolic activity of C. albicans cells, and an additive effect was also observed for the mixtures of peptides with amphotericin B. The results indicate the possible potential of the tested peptides in the prevention and treatment of candidiasis.}, }
@article {pmid36712378, year = {2022}, author = {Wang, C and Chantraine, C and Viljoen, A and Herr, AB and Fey, PD and Horswill, AR and Mathelié-Guinlet, M and Dufrêne, YF}, title = {The staphylococcal biofilm protein Aap mediates cell-cell adhesion through mechanically distinct homophilic and lectin interactions.}, journal = {PNAS nexus}, volume = {1}, number = {5}, pages = {pgac278}, pmid = {36712378}, issn = {2752-6542}, abstract = {The accumulation phase of staphylococcal biofilms relies on both the production of an extracellular polysaccharide matrix and the expression of bacterial surface proteins. A prototypical example of such adhesive proteins is the long multidomain protein Aap (accumulation-associated protein) from Staphylococcus epidermidis, which mediates zinc-dependent homophilic interactions between Aap B-repeat regions through molecular forces that have not been investigated yet. Here, we unravel the remarkable mechanical strength of single Aap-Aap homophilic bonds between living bacteria and we demonstrate that intercellular adhesion also involves sugar binding through the lectin domain of the Aap A region. We find that the mechanical force needed to unfold individual β-sheet-rich G5-E domains from the Aap B-repeat regions is very high, ranging from 300 up to 1,000 pN at high loading rates, indicating these are extremely stable. This high mechanostability provides a means to the cells to form highly adhesive and cohesive biofilms capable of sustaining high physiological shear stress. Importantly, we identify a previously undescribed role of Aap in bacterial-bacterial adhesion, that is, heterophilic sugar binding by a specific lectin domain located in the N-terminal A region, which might be important to establish initial contacts between cells before strong homophilic bonds come into play. This study emphasizes the remarkable mechanical and binding properties of Aap as well as its wide diversity of adhesive functions.}, }
@article {pmid36711324, year = {2023}, author = {Nunez, C and Kostoulias, X and Peleg, A and Short, F and Qu, Y}, title = {A comprehensive comparison of biofilm formation and capsule production for bacterial survival on hospital surfaces.}, journal = {Biofilm}, volume = {5}, number = {}, pages = {100105}, pmid = {36711324}, issn = {2590-2075}, abstract = {Biofilm formation and capsule production are known microbial strategies used by bacterial pathogens to survive adverse conditions in the hospital environment. The relative importance of these strategies individually is unexplored. This project aims to compare the contributory roles of biofilm formation and capsule production in bacterial survival on hospital surfaces. Representative strains of bacterial species often causing hospital-acquired infections were selected, including Acinetobacter baumannii, Klebsiella pneumoniae, Staphylococcus aureus, Staphylococcus epidermidis and Pseudomonas aeruginosa. The importance of biofilm formation and capsule production on bacterial survival was evaluated by comparing capsule-positive wild-type and capsule-deficient mutant strains, and biofilm and planktonic growth modes respectively, against three adverse hospital conditions, including desiccation, benzalkonium chloride disinfection and ultraviolet (UV) radiation. Bacterial survival was quantitatively assessed using colony-forming unit (CFU) enumeration and the 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay and qualitatively by scanning electron microscopy (SEM). Correlations between capsule production and biofilm formation were further investigated. Biofilm formation contributed significantly to bacterial survival on hospital surface simulators, mediating high resistance to desiccation, benzalkonium chloride disinfection and UV radiation. The role of capsule production was minor and species-specific; encapsulated A. baumannii but not K. pneumoniae cells demonstrated slightly increased resistance to desiccation, and neither showed enhanced resistance to benzalkonium chloride. Interestingly, capsule production sensitized K. pneumoniae and A. baumannii to UV radiation. The loss of capsule in K. pneumoniae and A. baumannii enhanced biofilm formation, possibly by increasing cell surface hydrophobicity. In summary, this study confirms the crucial role of biofilm formation in bacterial survival on hospital surfaces. Conversely, encapsulation plays a relatively minor role and may even negatively impact bacterial biofilm formation and hospital survival.}, }
@article {pmid36710254, year = {2023}, author = {Zhao, J and Li, F and Kong, S and Chen, T and Song, H and Wang, Z}, title = {Elongated Riboflavin-Producing Shewanella oneidensis in a Hybrid Biofilm Boosts Extracellular Electron Transfer.}, journal = {Advanced science (Weinheim, Baden-Wurttemberg, Germany)}, volume = {}, number = {}, pages = {e2206622}, doi = {10.1002/advs.202206622}, pmid = {36710254}, issn = {2198-3844}, abstract = {Shewanella oneidensis is able to carry out extracellular electron transfer (EET), although its EET efficiency is largely limited by low flavin concentrations, poor biofilm forming-ability, and weak biofilm conductivity. After identifying an important role for riboflavin (RF) in EET via in vitro experiments, the synthesis of RF is directed to 837.74 ± 11.42 µm in S. oneidensis. Molecular dynamics simulation reveals RF as a cofactor that binds strongly to the outer membrane cytochrome MtrC, which is correspondingly further overexpressed to enhance EET. Then the cell division inhibitor sulA, which dramatically enhanced the thickness and biomass of biofilm increased by 155% and 77%, respectively, is overexpressed. To reduce reaction overpotential due to biofilm thickness, a spider-web-like hybrid biofilm comprising RF, multiwalled carbon nanotubes (MWCNTs), and graphene oxide (GO) with adsorption-optimized elongated S. oneidensis, achieve a 77.83-fold increase in power (3736 mW m[-2]) relative to MR-1 and dramatically reduce the charge-transfer resistance and boosted biofilm electroactivity. This work provides an elegant paradigm to boost EET based on a synthetic biology strategy and materials science strategy, opens up further opportunities for other electrogenic bacteria.}, }
@article {pmid36709299, year = {2023}, author = {Yun, Z and Xianghong, L and Qianhua, G and Qin, D}, title = {Copper ions inhibit Streptococcus mutans-Veillonella parvula dual biofilm by activating Streptococcus mutans reactive nitrogen species.}, journal = {BMC oral health}, volume = {23}, number = {1}, pages = {48}, pmid = {36709299}, issn = {1472-6831}, abstract = {BACKGROUND: To investigate the inhibition mechanism of copper ions on Streptococcus mutans-Veillonella parvula dual biofilm.<br><br>METHODS: S. mutans-V. parvula dual biofilm was constructed and copper ions were added at different concentrations. After the biofilm was collected, RNA-seq and qRT-PCR were then performed to get gene information.<br><br>RESULTS: The coculture of S. mutans and V. parvula formed a significantly better dual biofilm of larger biomass than S. mutans mono biofilm. And copper ions showed a more significant inhibitory effect on S. mutans-V. parvula dual biofilm than on S. mutans mono biofilm when copper ions concentration reached 100&#xa0;&#xb5;M, and copper ions showed a decreased inhibitory effect on S. gordonii-V. parvula dual biofilm and S. sanguis-V.parvula dual biofilm than on the two mono biofilms as the concentration of copper ions increased. And common trace elements such as iron, magnesium, and zinc showed no inhibitory effect difference on S. mutans-V. parvula dual biofilm. The RNA-seq results showed a significant difference in the expression of a new ABC transporter SMU_651c, SMU_652c, SMU_653c, and S. mutans copper chaperone copYAZ. SMU_651c, SMU_652c, and SMU_653c were predicted to function as nitrite/nitrate transporter-related proteins, which suggested the specific inhibition of copper ions on S. mutans-V. parvula dual biofilm may be caused by the activation of S. mutans reactive nitrogen species.<br><br>CONCLUSIONS: Streptococcus mutans and Veillonella parvula are symbiotic, forming a dual biofilm of larger biomass to better resist the external antibacterial substances, which may increase the virulence of S. mutans. While common trace elements such as iron, magnesium, and zinc showed no specific inhibitory effect on S. mutans-V. parvula dual biofilm, copper ion had a unique inhibitory effect on S. mutans-V. parvula dual biofilm which may be caused by activating S. mutans RNS when copper ions concentration reached 250&#xa0;&#xb5;M.}, }
@article {pmid36709283, year = {2023}, author = {Ham, Y and Kim, TJ}, title = {Synergistic inhibitory activity of Glycyrrhizae Radix and Rubi Fructus extracts on biofilm formation of Streptococcus mutans.}, journal = {BMC complementary medicine and therapies}, volume = {23}, number = {1}, pages = {22}, pmid = {36709283}, issn = {2662-7671}, abstract = {BACKGROUND: Streptococcus mutans is a bacterium that causes oral diseases. Plaque, a biofilm produced by S. mutans and other bacteria, makes it difficult to remove cariogenic oral microorganisms, including biofilm producers. Glucan synthesis by glucosyltransferase is one of the mechanisms underlying plaque formation. This study demonstrates the effectiveness of inhibiting biofilm formation by interfering with the glucosyltransferase activity of S. mutans using edible herbal medicines.<br><br>METHODS: This study investigated the inhibitory activity of Glycyrrhizae Radix extract, Rubi Fructus extract, glycyrrhizin from Glycyrrhizae Radix, and ellagic acid from Rubi Fructus against glucosyltransferase activity of S. mutans. Enzyme kinetic analysis identified the mechanism by which glycyrrhizin and ellagic acid inhibit enzyme activity.<br><br>RESULTS: The conditions for synergistically inhibiting biofilm formation by combining Glycyrrhizae Radix and Rubi Fructus extracts were identified. Biofilm formation was also synergistically inhibited by mixing their respective active constituents, glycyrrhizin and ellagic acid. Glycyrrhizin and ellagic acid inhibited glucosyltransferase via noncompetitive and uncompetitive mechanisms, respectively, indicating that they inhibit it via distinct mechanisms.<br><br>CONCLUSIONS: This study presents an effective oral hygiene method using the synergistic activity of two natural plant extracts to inhibit biofilm formation through different inhibitory mechanisms against glucosyltransferase of S. mutans.}, }
@article {pmid36709017, year = {2023}, author = {Pourhajibagher, M and Parker, S and Pourakbari, B and Valian, NK and Raoofian, R and Bahador, A}, title = {Enhancement of hypericin nanoparticle-mediated sonoinduced disruption of biofilm and persister cells of Streptococcus mutans by dermcidin-derived peptide DCD-1L.}, journal = {Photodiagnosis and photodynamic therapy}, volume = {}, number = {}, pages = {103308}, doi = {10.1016/j.pdpdt.2023.103308}, pmid = {36709017}, issn = {1873-1597}, abstract = {BACKGROUND: Streptococcus mutans is considered a major significant contributor to dental caries and its effective removal is difficult due to the formation of biofilm. Therefore, the development of adjuvant therapeutic strategies with anti-biofilm properties is a promising approach. In the present study, we examined the effect of dermcidin-derived peptide DCD-1L on the antibacterial activity of hypericin nanoparticle (HypNP)-mediated antimicrobial sonodynamic therapy (aSDT) against persister cells growing- and biofilm cultures of S. mutans.<br><br>MATERIALS AND METHODS: Following synthesis and confirmation of HypNP, the fractional inhibitory concentration (FIC) index of HypNP and DCD-1L was determined by checkerboard assay. Cellular uptake of HypNP-DCD-1L and generation of endogenous reactive oxygen species (ROS) were assessed and followed by the determination of antimicrobial sonoactivity of HypNP-DCD-1L against persister cells growing- and biofilm cultures of S. mutans. The water-insoluble extracellular polysaccharide (EPS) and expression of the gtfD, comDE, and smuT genes were then evaluated in persister cells growing- and biofilm cultures of S. mutans.<br><br>RESULTS: There was a synergistic activity in the combination of HypNP and DCD-1L against S. mutans with an FIC index value of 0.37. The HypNP-DCD-1L-mediated aSDT also displayed the highest cellular uptake and endogenous ROS generation by bacterial cells. When biofilm and persister cells of S. mutans were treated with HypNP-DCD-1L and subsequently exposed to ultrasound waves, 5.1 log and 3.8 log reductions, respectively, in bacterial numbers were observed (P<0.05). According to the data, EPS in both persister cells growing- and biofilm cultures of S. mutans were significantly decreased after exposure to the HypNP-DCD-1L-mediated aSDT (P<0.05). In addition, the quantitative real-time PCR data illustrated the high level of similarities in very low-expression profiles of the gtfD before and after all treated groups for persister cells. While, following HypNP-DCD-1L-mediated aSDT treatment, the expression levels of gtfD, comDE, and smuT were significantly lower in treated persister cells growing- and biofilm cultures of S. mutans in comparison with control groups (P<0.05).<br><br>CONCLUSIONS: Combined, the results of this study indicate that ultrasound waves-activated HypNP-DCD-1L can sonoinactivate S. mutans biofilms and persister cells, as well as reduce effectively pathogenicity potency of S. mutans. Hence, HypNP-DCD-1L-mediated aSDT may be proposed as a promising adjunctive therapeutic approach for dental caries.}, }
@article {pmid36707288, year = {2023}, author = {Kraft, L and Ribeiro, VST and Gonçalves, GA and Suss, PH and Tuon, FF}, title = {Comparison of amphotericin B lipid complex, deoxycholate amphotericin B, fluconazole, and anidulafungin activity against Candida albicans biofilm isolated from breakthrough candidemia.}, journal = {Enfermedades infecciosas y microbiologia clinica (English ed.)}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.eimce.2022.07.009}, pmid = {36707288}, issn = {2529-993X}, abstract = {INTRODUCTION: Biofilm formation causes virulence and resistance in Candida albicans. However, little is known about breakthrough candidemia isolates. We evaluated the antifungal activity of fluconazole, anidulafungin, deoxycholate amphotericin B (dAMB), and amphotericin B lipid complex (ABLC) against biofilms of C. albicans isolated from patients with breakthrough candidemia.<br><br>METHODS: The present study used strains of C. albicans isolated from breakthrough and non-breakthrough candidemia patients (control group). The susceptibility of planktonic cells to amphotericin B, anidulafungin, and fluconazole was determined by broth microdilution. Antifungal activity in sessile cells was evaluated using the minimum biofilm eradication concentration (MBEC), metabolic activity was estimated by reducing MTT, and biomass was estimated using crystal violet retention.<br><br>RESULTS: The planktonic strains were susceptible to amphotericin B, anidulafungin, and fluconazole, with minimum inhibitory concentrations of 1, &#x2264;0.03, and 2mg/L, respectively. However, fluconazole and anidulafungin did not exert an antifungal effect on biofilms. Additionally, dAMB and ABCL reduced the metabolic activity and biomass. However, eradication was only achieved using 16mg/L dAMB. C. albicans isolates of breakthrough candidemia exhibited strong biofilm production, and the in vitro activity of available therapeutic options was poor.<br><br>CONCLUSION: In the present study, only dAMB and ABCL exhibited antibiofilm effects against sessile breakthrough candidemia isolates.}, }
@article {pmid36706296, year = {2023}, author = {}, title = {Corrigendum: Water Sci Technol (2022) 86 (6): 1578-1589: Degradation of tetracycline wastewater by suspended biochar as carriers in moving bed biofilm reactor, Shaoqin Liu, Hanyu Chen, Xueqi Zhang, Baozhong Zhang, Huina Zhu, Hongxia Chen, Bo Wen, Lefei Chen.}, journal = {Water science and technology : a journal of the International Association on Water Pollution Research}, volume = {87}, number = {2}, pages = {508}, doi = {10.2166/wst.2023.017}, pmid = {36706296}, issn = {0273-1223}, }
@article {pmid36705272, year = {2023}, author = {Sharan, M and Dhaka, P and Bedi, JS and Singh, R and Mehta, N}, title = {Characterization of chicken eggs associated Escherichia coli and Staphylococcus aureus for biofilm production and antimicrobial resistance traits.}, journal = {Animal biotechnology}, volume = {}, number = {}, pages = {1-12}, doi = {10.1080/10495398.2023.2171423}, pmid = {36705272}, issn = {1532-2378}, abstract = {The present study assessed the prevalence, virulence characteristics, antimicrobial resistance and biofilm-forming ability of E. coli and S. aureus recovered from egg samples in Ludhiana, Punjab. A total of 393 samples from hatcheries (n = 238), retail shops (n = 94), and households (n = 61) were collected. The prevalence of E. coli was observed as 11.70% and 9.16% for S. aureus. A total of 41.30% of E. coli isolates were positive for aggR gene and 52.17% were for fimA gene; while 36.11% of the S. aureus isolates were positive for coa gene. A high proportion of E. coli (76.10%) and S. aureus (69.44%) isolates were resistant toward ≥3 tested antibiotic classes. A total of 39.13% of E. coli isolates were moderate biofilm former, whereas the majority of the S. aureus (41.67%) were weak biofilm former. No significant difference regarding biofilm formation was observed between MDR and non-MDR isolates of E. coli and S. aureus. Biofilm genes viz., fimC and crl were reported in 43.47% and 80.43% of E. coli isolates, respectively; while icaA and icaD genes were reported in 58.34% and 47.22% of S. aureus isolates, respectively. A strong metabolic activity among 52.17% of E. coli and 41.66% of S. aureus isolates was observed using XTT assay. The present study highlights the need for applied food safety measures across the egg production chain of the region to prevent the development of MDR strains and biofilms.}, }
@article {pmid36705135, year = {2022}, author = {Pokharel, K and Dawadi, BR and Shrestha, LB}, title = {Role of Biofilm in Bacterial Infection and Antimicrobial Resistance.}, journal = {JNMA; journal of the Nepal Medical Association}, volume = {60}, number = {253}, pages = {836-840}, doi = {10.31729/jnma.7580}, pmid = {36705135}, issn = {1815-672X}, abstract = {Biofilm refers to the complex, sessile communities of microbes found either attached to a surface or buried firmly in an extracellular matrix as aggregates. Microbial flora which produces biofilm manifests an altered growth rate and transcribes genes that provide them resistance to antimicrobial and host immune systems. Biofilms protect the invading bacteria against the immune system of the host via impaired activation of phagocytes and the complement system. Biofilm-producing isolates showed greater multidrug resistance than non-biofilm producers. Biofilm causes antibiotic resistance through processes like chromosomally encoded resistant genes, restriction of antibiotics, reduction of growth rate, and host immunity. Biofilm formation is responsible for the development of superbugs like methicillin-resistant Staphylococcus aureus, vancomycin-resistant Staphylococcus aureus, and metallo-beta-lactamase producing Pseudomonas aeruginosa. Regular monitoring of antimicrobial resistance and maintaining hygiene, especially in hospitalized patients are required to control biofilm-related infections in order to prevent antimicrobial resistance.}, }
@article {pmid36704568, year = {2022}, author = {Rodríguez-Temporal, D and Díez, R and Díaz-Navarro, M and Escribano, P and Guinea, J and Muñoz, P and Rodríguez-Sánchez, B and Guembe, M}, title = {Determination of the ability of matrix-assisted laser desorption ionization time-of-flight mass spectrometry to identify high-biofilm-producing strains.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1104405}, pmid = {36704568}, issn = {1664-302X}, abstract = {BACKGROUND: The traditional method for assessing the capacity of a microorganism to produce biofilm is generally a static in vitro model in a multi-well plate using the crystal violet (CV) binding assay, which takes 96 h. Furthermore, while the method is simple to perform, its reproducibility is poor.<br><br>OBJECTIVE: We evaluated whether matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) could make it possible to differentiate between high-and low-biofilm-producing microorganisms on 24-h cultures of Staphylococcus aureus and Candida albicans.<br><br>METHODS: We included 157 strains of S. aureus and 91 strains of C. albicans obtained from the blood cultures of patients with bacteremia/candidemia. We tested biofilm production using the CV binding assay as the gold standard to classify strains as low or high biofilm producers. We then applied MALDI-TOF MS to create a machine learning-based predictive model using 40 strains of S. aureus and C. albicans, each with extreme absorbance values, and validated this approach with the remaining 117 and 51 strains using the random forest algorithm and the support vector machine algorithm, respectively.<br><br>RESULTS: Overall, 81.2% of the S. aureus strains (95/117) and 74.5% of the C. albicans strains (38/51) used for validation were correctly categorized, respectively, as low and high-biofilm-producing.<br><br>CONCLUSION: Classification based on MALDI-TOF MS protein spectra enables us to predict acceptable information about the capacity of 24-h cultures of S. aureus and C. albicans to form biofilm.}, }
@article {pmid36704545, year = {2022}, author = {Costa, MOCE and do Nascimento, APB and Martins, YC and Dos Santos, MT and Figueiredo, AMS and Perez-Rueda, E and Nicolás, MF}, title = {The gene regulatory network of Staphylococcus aureus ST239-SCCmecIII strain Bmb9393 and assessment of genes associated with the biofilm in diverse backgrounds.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1049819}, pmid = {36704545}, issn = {1664-302X}, abstract = {INTRODUCTION: Staphylococcus aureus is one of the most prevalent and relevant pathogens responsible for a wide spectrum of hospital-associated or community-acquired infections. In addition, methicillin-resistant Staphylococcus aureus may display multidrug resistance profiles that complicate treatment and increase the mortality rate. The ability to produce biofilm, particularly in device-associated infections, promotes chronic and potentially more severe infections originating from the primary site. Understanding the complex mechanisms involved in planktonic and biofilm growth is critical to identifying regulatory connections and ways to overcome the global health problem of multidrug-resistant bacteria.<br><br>METHODS: In this work, we apply literature-based and comparative genomics approaches to reconstruct the gene regulatory network of the high biofilm-producing strain Bmb9393, belonging to one of the highly disseminating successful clones, the Brazilian epidemic clone. To the best of our knowledge, we describe for the first time the topological properties and network motifs for the Staphylococcus aureus pathogen. We performed this analysis using the ST239-SCCmecIII Bmb9393 strain. In addition, we analyzed transcriptomes available in the literature to construct a set of genes differentially expressed in the biofilm, covering different stages of the biofilms and genetic backgrounds of the strains.<br><br>RESULTS AND DISCUSSION: The Bmb9393 gene regulatory network comprises 1,803 regulatory interactions between 64 transcription factors and the non-redundant set of 1,151 target genes with the inclusion of 19 new regulons compared to the N315 transcriptional regulatory network published in 2011. In the Bmb9393 network, we found 54 feed-forward loop motifs, where the most prevalent were coherent type 2 and incoherent type 2. The non-redundant set of differentially expressed genes in the biofilm consisted of 1,794 genes with functional categories relevant for adaptation to the variable microenvironments established throughout the biofilm formation process. Finally, we mapped the set of genes with altered expression in the biofilm in the Bmb9393 gene regulatory network to depict how different growth modes can alter the regulatory systems. The data revealed 45 transcription factors and 876 shared target genes. Thus, the gene regulatory network model provided represents the most up-to-date model for Staphylococcus aureus, and the set of genes altered in the biofilm provides a global view of their influence on biofilm formation from distinct experimental perspectives and different strain backgrounds.}, }
@article {pmid36704397, year = {2021}, author = {Tour Savadkouhi, S and Mohtasham Maram, M and Purhaji Bagher, M and Afkar, M and Fazlyab, M}, title = {In Vitro Activity of Superoxide Water on Viability of Enterococcus faecalis Biofilm on Root Canal Wall.}, journal = {Iranian endodontic journal}, volume = {16}, number = {3}, pages = {189-192}, pmid = {36704397}, issn = {2008-2746}, abstract = {INTRODUCTION: The aim of this study was to compare the effect of root canal irrigation with superoxidized water and sodium hypochlorite on elimination of Enterococcus faecalis biofilm from the root canal walls.<br><br>METHODS AND MATERIALS: In this experimental study, a total of 32 extracted human central incisors were used. The crowns of all teeth were cut to length of 16 mm. After cleaning and shaping, then the specimens were sterilized in autoclave and then divided into four groups (n=8) as following: group 1 (positive control, root canal irrigation with normal saline), group 2 (negative control without biofilm), group 3 (root canal irrigation with sodium hypochlorite) and group 4 (root canal irrigation with superoxidized water). The bacterial suspension was inserted to root canals of teeth except for negative control group in order to form a microbial biofilm in incubator for 2 weeks. Then all the samples received root canal irrigation for 5 min based on their allocation. At the end, colony forming unit (CFU) was evaluated and biofilm formation and thickness was detected with scanning electron microscopy. The Kruskal Wallis and Dunn's tests were done for biofilm thickness and CFU, respectively with the level of significance set at 0.05.<br><br>RESULTS: In negative control group no biofilm formation and CFU was present. The CFU counts and biofilm thickness were significantly different between the experimental groups (P=0.001) and both parameters were less in samples with hypochlorite irrigation compared to positive control (52.56&#xb1;5.82 &#xb5;m for biofilm thickness and 1.2&#xd7;10[7] CFU) and samples irrigated with superoxidized water (2.92&#xb1;1.76 &#xb5;m for biofilm thickness and 5.4&#xd7;10[4] CFU).<br><br>CONCLUSION: Based on this in vitro study reduction in biofilm thickness and CFU/mL was 100% for sodium hypochlorite and for superoxidized water was 98% and 90% for reduction in biofilm thickness and CFU/mL, respectively.}, }
@article {pmid36703803, year = {2020}, author = {Byakova, SF and Dezhurko-Korol, VA and Novozhilova, NE and Makeeva, IM and Lukashev, AN and Akhmadishina, LV and Semenov, AM and Moisenovich, MM and Arkhipova, AY and Ponirovsky, EN}, title = {Quantitative Assessment of Dentinal Tubule Disinfection in Absence of Biofilm on Root Canal Walls: An in vitro Study.}, journal = {Iranian endodontic journal}, volume = {15}, number = {3}, pages = {155-165}, pmid = {36703803}, issn = {2008-2746}, abstract = {INTRODUCTION: This study aimed at assessing the quantitative effect of calcium hydroxide, 2% chlorhexidine gel, and 1.5% chlorhexidine linked to xanthan gel specifically against intratubular bacteria.<br><br>METHODS AND MATERIALS: Fifty-two semi-cylindrical bovine dentin specimens were infected with Enterococcus (E.) faecalis by centrifugation with subsequent 7-days incubation. The surface of specimens was disinfected with 3% H2O2. Scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and the count of bacterial colony-forming units (CFU/mg) were used to assess dentin infection. A total of 40 specimens were incubated for 2 weeks with one of the intracanal medication applied (10 samples for each group): 1) calcium hydroxide, 2) 2% chlorhexidine gel, 3) 1.5% chlorhexidine linked to xanthan gel and 4) sterile saline. Final passive ultrasonic irrigation with 3% sodium hypochlorite was performed in half of the total specimens. The effect of intracanal medications and irrigation against intratubular bacteria was assessed by bacterial culturing of dentin shavings. Two-Way ANOVA model was applied followed by post-hoc Tukey's test for multiple pair-wise comparisons of mean CFU/mg values.<br><br>RESULTS: SEM, CLSM, and bacterial culturing confirmed the absence of the surface biofilm on the root canal wall and showed vital intratubular bacteria at the depth up to 700 &#xa0;m. Two-week application of 1.5% chlorhexidine with xanthan gel and 2% chlorhexidine gel significantly decreased intratubular bacterial counts compared with saline (P=0.0003 and P=0.0005, respectively). Subsequent passive ultrasonic irrigation with 3% sodium hypochlorite significantly reduced the number of intratubular bacteria in all groups except for the group with 1.5% chlorhexidine-xanthan gel (P=0.0054).<br><br>CONCLUSION: This modified ex vivo model study showed ultrasonically activated irrigation with sodium hypochlorite had greater effect on intratubular bacteria counts compared with 2-week application of intracanal medications.}, }
@article {pmid36702549, year = {2023}, author = {Firdose, A and Chong, NHH and Ramli, R and Aqma, WS}, title = {Antimicrobial, Anti-adhesive and Anti-biofilm Actions of Rhamnolipids on ESKAPE Pathogens.}, journal = {Letters in applied microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/lambio/ovad013}, pmid = {36702549}, issn = {1472-765X}, abstract = {The aim of this study was to test the antimicrobial, anti-adhesive and anti-biofilm activities of a rhamnolipid extracted from Pseudomonas aeruginosa UKMP14T previously isolated from oil contaminated soil in Malaysia against ESKAPE (i.e. multidrug resistant) pathogens. Zones of inhibition in an agar well diffusion assay were observed at 50 μg mL-1 concentrations of rhamnolipid for all the ESKAPE bacteria. The MIC and MBC values ranged between 7.81-62.5 µg mL-1 and 31.25-1000 µg mL-1, respectively. Percent killing was recorded to be more than 90% except for Klebsiella pneumoniae (86.84%). Furthermore, anti-adhesion studies showed that there was 76% hindrance in attachment of E. faecium and 91% in Acinetobacter baumannii at 4xMIC. The highest inhibition in adhesion was found at 4xMIC, which was 46% for A. baumannii and 62% for Enterococcus faecium. Finally, the anti-biofilm capability of the rhamnolipid was determined which ranged between 25%-76% in A. baumannii and 35%-88% in E. faecium. To the best of our knowledge, this is the first study to include research on antimicrobial, anti-adhesive and anti-biofilm activities of rhamnolipid from the local isolate P. aeruginosa UKMP14T against ESKAPE bacteria. Obtained results suggest that this rhamnolipid can be exploited commercially for the production of novel antibiotics.}, }
@article {pmid36702412, year = {2023}, author = {Yuan, Q and Jia, Z and Roots, P and Wells, G}, title = {A strategy for fast anammox biofilm formation under mainstream conditions.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {137955}, doi = {10.1016/j.chemosphere.2023.137955}, pmid = {36702412}, issn = {1879-1298}, abstract = {One of the bottlenecks to applying anaerobic ammonium oxidation (Anammox) is the long start-up time, especially under mainstream conditions. This study proposed a strategy for fast anammox biofilm formation under mainstream conditions. By first cultivating an aerobic heterotrophic biofilm, and then transferring to anoxic conditions, a pre-cultivated heterotrophic biofilm can be formed in 12 days. The pre-cultivated heterotrophic biofilm then functions as a "glue" to accelerate anammox bacteria adhesion and biofilm formation. Secondary settled effluent with externally added 15-30 mg-N·L[-1] ammonium and nitrite was applied as reactor influent. With a single inoculation of suspended growth anammox-laden biomass and no bioaugmentation, an anammox-enriched biofilm formed after 5 months of operation under uncontrolled temperature of 15-20 °C. Both the nitrogen removal rate and specific anammox activity exponentially increased over the course of study, corresponding to an estimated anammox doubling time of 10.8 days. The biofilm thickness on primed carriers was 2-3 times higher than on the non-primed carriers over the first 5 months of operation, and the hszA gene copy number in primed biofilms revealed was consistently 1 to 2 times higher than the non-primed carrier biofilm, indicating that biofil m carrier priming via selection for a pre-cultivated heterotrophic biofilm base can effectively improve the anammox enrichment rate at early stages of reactor operation. Time, rather than the type of biofilm (primed versus non-primed), had a stronger influence on microbial community structure over the full 230 days of reactor operation. Candidatus Brocadia was the only detected anammox bacteria genus. Overall, pre-cultivation of heterotrophs on biofilm carriers provides a simple route to accelerate anammox-enriched biofilm formation under mainstream conditions.}, }
@article {pmid36702020, year = {2023}, author = {Jang, Y and Lee, SH and Kim, NK and Ahn, CH and Rittmann, BE and Park, HD}, title = {Biofilm characteristics for providing resilient denitrification in a hydrogen-based membrane biofilm reactor.}, journal = {Water research}, volume = {231}, number = {}, pages = {119654}, doi = {10.1016/j.watres.2023.119654}, pmid = {36702020}, issn = {1879-2448}, abstract = {In a hydrogen-based membrane biofilm reactor (H2-MBfR), the biofilm thickness is considered to be one of the most important factors for denitrification. Thick biofilms in MBfRs are known for low removal fluxes owing to their resistance to substrate transport. In this study, the H2-MBfR was operated under various loading rates of oxyanions, such as NO3-N, SO4-S, and ClO4[-] at an H2 flux of 1.06 e[-] eq/m[2]-d. The experiment was initiated with NO3-N, SO4-S, and ClO4[-] loadings of 0.464, 0.026, and 0.211 e[-] eq/m[2]-d, respectively, at 20 °C. Under the most stressful conditions, the loading rates increased simultaneously to 1.911, 0.869, and 0.108 e[-] eq/m[2]-d, respectively, at 10 °C. We observed improved performance in significantly thicker biofilms (approximately 2.7 cm) compared to previous studies using a denitrifying H2-MBfR for 120 days. Shock oxyanion loadings led to a decrease in total nitrogen (TN) removal by 20 to 30%, but TN removal returned to 100% within a few days. Similarly, complete denitrification was observed, even at 10 °C. The protective function and microbial diversity of the thick biofilm may allow stable denitrification despite stress-imposing conditions. In the microbial community analysis, heterotrophs were dominant and acetogens accounted for 11% of the biofilm. Metagenomic results showed a high abundance of functional genes involved in organic carbon metabolism and homoacetogenesis. Owing to the presence of organic compounds produced by acetogens and autotrophs, heterotrophic denitrification may occur simultaneously with autotrophic denitrification. As a result, the total removal flux of oxyanions (1.84 e[-] eq/m[2]-d) far exceeded the H2 flux (1.06 e[-] eq/m[2]-d). Thus, the large accumulation of biofilms could contribute to good resilience and enhanced removal fluxes.}, }
@article {pmid36700647, year = {2023}, author = {Barraza, I and Pajon, C and Diaz-Tang, G and Marin Meneses, E and Abu-Rumman, F and García-Diéguez, L and Castro, V and Lopatkin, AJ and Smith, RP}, title = {Disturbing the Spatial Organization of Biofilm Communities Affects Expression of agr-Regulated Virulence Factors in Staphylococcus aureus.}, journal = {Applied and environmental microbiology}, volume = {}, number = {}, pages = {e0193222}, doi = {10.1128/aem.01932-22}, pmid = {36700647}, issn = {1098-5336}, abstract = {Staphylococcus aureus uses quorum sensing and nutrient availability to control the expression of agr-regulated virulence factors. Quorum sensing is mediated by autoinducing peptide (AIP), which at a high concentration reduces expression of surface attachment proteins (coa, fnbpA) and increases expression of exotoxins (lukS) and proteases (splA). Nutrient availability can be sensed through the saeS/saeR system. Low nutrients increase expression of saeR, which augments expression of coa and fnbpA, distinct from the activity of AIP. The formation of spatial structure, such as biofilms, can alter quorum sensing and nutrient acquisition. In natural environments, biofilms encounter forces that may alter their spatial structure. These forces may impact quorum sensing and/or nutrient acquisition and thus affect the expression of agr-regulated virulence factors. However, this has not been studied. We show that periodically disturbing biofilms composed of S. aureus using a physical force affected the expression of agr-regulated virulence factors. In nutrient-poor environments, disturbance increased the expression of coa, fnbpA, lukS, and splA. Disturbance in a nutrient-rich environment at low or high disturbance amplitudes moderately reduced expression of coa and fnbpA but increased expression of lukS and splA. Interestingly, at an intermediate amplitude, the overall expression of agr-regulated virulence factors was the lowest; expression of lukS and splA remained unchanged relative to an undisturbed biofilm, while expression of coa and fnbpA significantly decreased. We hypothesize that these changes are a result of disturbance-driven changes in access to AIP and nutrients. Our results may allow the identification of environments where virulence is enhanced, or reduced, owing to a disturbance. IMPORTANCE Bacteria, such as Staphylococcus aureus, integrate signals from the environment to regulate genes encoding virulence factors. These signals include those produced by quorum-sensing systems and nutrient availability. We show that disturbing the spatial organization of S. aureus populations can lead to changes in the expression of virulence factors, likely by altering the ways in which S. aureus detects these signals. Our work may allow us to identify environments that increase or reduce the expression of virulence factors in S. aureus.}, }
@article {pmid36699726, year = {2022}, author = {Shen, Y and Yu, F and Qiu, L and Gao, M and Xu, P and Zhang, L and Liao, X and Wang, M and Hu, X and Sun, Y and Pan, Y}, title = {Ecological influence by colonization of fluoride-resistant Streptococcus mutans in oral biofilm.}, journal = {Frontiers in cellular and infection microbiology}, volume = {12}, number = {}, pages = {1106392}, pmid = {36699726}, issn = {2235-2988}, abstract = {BACKGROUND: Dental caries is one of the oldest and most common infections in humans. Improved oral hygiene practices and the presence of fluoride in dentifrices and mouth rinses have greatly reduced the prevalence of dental caries. However, increased fluoride resistance in microbial communities is concerning. Here, we studied the effect of fluoride-resistant Streptococcus mutans (S. mutans) on oral microbial ecology and compare it with wild-type S. mutans in vitro.<br><br>METHODS: Biofilm was evaluated for its polysaccharide content, scanning electron microscopy (SEM) imaging, acid-producing ability, and related lactic dehydrogenase (LDH), arginine deiminase (ADS), and urease enzymatic activity determination. Fluorescence in situ hybridization (FISH) and quantitative real-time polymerase chain reaction (qRT-PCR) were used to evaluate the S. mutans ratio within the biofilm. It was followed by 16S rRNA sequencing to define the oral microbial community.<br><br>RESULTS: Fluoride-resistant S. mutans produced increased polysaccharides in presence of NaF (P < 0.05). The enzymatic activities related to both acid and base generation were less affected by the fluoride. In presence of 275 ppm NaF, the pH in the fluoride-resistant strain sample was lower than the wild type. We observed that with the biofilm development and accumulative fluoride concentration, the fluoride-resistant strain had positive relationships with other bacteria within the oral microbial community, which enhanced its colonization and survival. Compared to the wild type, fluoride-resistant strain significantly increased the diversity and difference of oral microbial community at the initial stage of biofilm formation (4 and 24 h) and at a low fluoride environment (0 and 275 ppm NaF) (P < 0.05). Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that fluoride-resistant strain enhanced the metabolic pathways and glucose transfer.<br><br>CONCLUSIONS: Fluoride-resistant S. mutans affected the microecological balance of oral biofilm and its cariogenic properties in vitro, indicating its negative impact on fluoride's caries prevention effect.}, }
@article {pmid36699581, year = {2022}, author = {Liu, S and Xiong, Y and Xiao, H and Zheng, J and Wen, Z and Li, D and Deng, Q and Yu, Z}, title = {Inhibition of planktonic growth and biofilm formation of Staphylococcus aureus by entrectinib through disrupting the cell membrane.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1106319}, pmid = {36699581}, issn = {1664-302X}, abstract = {Over the last few decades, Staphylococcus aureus infection remain a major medical challenge and health concern worldwide. Biofilm formation and antibiotic resistance caused by S. aureus make it difficult to be eradicated from bacterial infections in clinics. In this study, our data demonstrated the antibacterial and excellent anti-biofilm activity of entrectinib against S. aureus. Entrectinib also exhibited the good safety, suggesting no toxicity with antibacterial concentration of entrectinib toward the erythrocytes and mammalian 239 T cells. Moreover, entrectinib significantly reduced the bacterial burden of septic tissue in a murine model of MRSA infection. Global proteomic analysis of S. aureus treated with entrectinib showed significant changes in the expression levels of ribosomal structure-related (rpmC, rpmD, rplX, and rpsT) and oxidative stress-related proteins (Thioredoxin system), suggesting the possible inhibition of bacterial protein biosynthesis with entrectinib exposure. The increased production of reactive oxygen species (ROS) was demonstrated in the entrectinib-treated S. aureus, supported the impact of entrectinib on the expression changes of ROS-correlated proteins involved in oxidative stress. Furthermore, entrectinib-induced resistant S. aureus clone was selected by in vitro induction under entrectinib exposure and 3 amino acid mutations in the entrectinib-induced resistant S. aureus strain, 2 of which were located in the gene encoding Type II NADH: quinoneoxidoreductase and one were found in GTP pyrophosphokinase family protein. Finally, the bactericidal action of entrectinib on S. aureus were confirmed by disrupting the bacterial cell membrane. Conclusively, entrectinib exhibit the antibacterial and anti-biofilm activity by destroying cell membrane against S. aureus.}, }
@article {pmid36698450, year = {2022}, author = {Hussain Akbar, J and Behbehani, J and Karched, M}, title = {Biofilm growth and microbial contamination of dental unit waterlines at Kuwait University dental center.}, journal = {Frontiers in oral health}, volume = {3}, number = {}, pages = {1071018}, pmid = {36698450}, issn = {2673-4842}, abstract = {Biofilm formation in dental unit waterlines and the resulting microbial contamination of the water in the system has become a significant problem. Contaminated water in the dental units is a major concern in dental clinics due to potential risk of causing infections particularly in elderly and immunocompromised patients. The aim of this study was at first to determine microbial contamination of the dental unit waterlines and then to study the efficacy of a comprehensive disinfection protocol on decreasing the microbial load. Water samples were collected before and after disinfection procedure from handpieces and water storage bottles from the dental units, a small 1-cm tubing was cut from each unit and subjected to microbiological culture on different growth media. Identification of the predominant species was achieved by 16S rRNA gene sequencing. Microbial growth was observed in samples collected from all dental units. Upon disinfection procedure, microbial contamination in the water samples and in the tubing surfaces was significantly reduced (P > 0.05). 16S rRNA gene sequencing revealed the presence of several species belonging to the genera Staphylococcus, Corynebacterium and Roseomonas, some of which are implicated in human infections. Aggravation of the biofilm growth on the tubing surfaces and the microbial contamination in the water can be effectively controlled by implementing appropriate and routine disinfection protocols. This may help protect the dental unit staff and the patients being exposed to the risk of infections.}, }
@article {pmid36697414, year = {2023}, author = {Mourer, T and El Ghalid, M and Pehau-Arnaudet, G and Kauffmann, B and Loquet, A and Brûlé, S and Cabral, V and d'Enfert, C and Bachellier-Bassi, S}, title = {The Pga59 cell wall protein is an amyloid forming protein involved in adhesion and biofilm establishment in the pathogenic yeast Candida albicans.}, journal = {NPJ biofilms and microbiomes}, volume = {9}, number = {1}, pages = {6}, pmid = {36697414}, issn = {2055-5008}, abstract = {The human commensal fungus Candida albicans can attach to epithelia or indwelling medical devices and form biofilms, that are highly tolerant to antifungal drugs and can evade the immune response. The cell surface protein Pga59 has been shown to influence adhesion and biofilm formation. Here, we present evidence that Pga59 displays amyloid properties. Using electron microscopy, staining with an amyloid fibre-specific dye and X-ray diffraction experiments, we showed that the predicted amyloid-forming region of Pga59 is sufficient to build up an amyloid fibre in vitro and that recombinant Pga59 can also adopt a cross-β amyloid fibre architecture. Further, mutations impairing Pga59 amyloid assembly led to diminished adhesion to substrates and reduced biofilm production. Immunogold labelling on amyloid structures extracted from C. albicans revealed that Pga59 is used by the fungal cell to assemble amyloids within the cell wall in response to adhesion. Altogether, our results suggest that Pga59 amyloid properties are used by the fungal cell to mediate cell-substrate interactions and biofilm formation.}, }
@article {pmid36696596, year = {2023}, author = {Kim, J and Choi, Y and Park, J and Choi, J}, title = {Gelatin-Gallic Acid Microcomplexes Release GO/Cu Nanomaterials to Eradicate Antibiotic-Resistant Microbes and Their Biofilm.}, journal = {ACS infectious diseases}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsinfecdis.2c00439}, pmid = {36696596}, issn = {2373-8227}, abstract = {Wound-infecting bacteria are typically Pseudomonas aeruginosa and Staphylococcus epidermidis, both of which form biofilms and become resistant to antibiotics. To solve this problem, copper nanoparticles (Cu) on graphene oxide (GO) nanosheets were used as antibacterial materials. Since the excessive use of antibacterial substances is fatal to normal tissues, GO/Cu was encapsulated with a gelatin complex to lower the cytotoxicity. Among the catechol-based substances, gallic acid (GA), which has anti-inflammatory and antibacterial properties, was used in this study to impart stability to the gelatin complex. Gelatin (GE) and gallic acid (GA) were combined by a crosslinking method using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC)/N-hydroxysuccinimide (NHS) as a crosslinker, and the crosslinking was confirmed by Fourier transform infrared (FT-IR), [1]H NMR, and the fluorescence property of GA. The GO/Cu@GE-GA microcomplexes exhibited more antibacterial effect against Gram-positive bacteria (S. epidermidis) and Gram-negative bacteria (P. aeruginosa) than when GO/Cu alone was used, and the antibiofilm effect was also confirmed. The cytotoxicity evaluation for human skin cells (human dermal fibroblast (HDF)) at the same concentration showed that it had low cytotoxicity and biocompatibility. This study shows the potential of antimicrobial gelatin microcomplex in prohibiting infectious bacteria and their biofilms and controlling the release of antimicrobial substances.}, }
@article {pmid36696507, year = {2023}, author = {Dubern, JF and Hook, AL and Carabelli, AM and Chang, CY and Lewis-Lloyd, CA and Luckett, JC and Burroughs, L and Dundas, AA and Humes, DJ and Irvine, DJ and Alexander, MR and Williams, P}, title = {Discovery of a polymer resistant to bacterial biofilm, swarming, and encrustation.}, journal = {Science advances}, volume = {9}, number = {4}, pages = {eadd7474}, doi = {10.1126/sciadv.add7474}, pmid = {36696507}, issn = {2375-2548}, abstract = {Innovative approaches to prevent catheter-associated urinary tract infections (CAUTIs) are urgently required. Here, we describe the discovery of an acrylate copolymer capable of resisting single- and multispecies bacterial biofilm formation, swarming, encrustation, and host protein deposition, which are major challenges associated with preventing CAUTIs. After screening ~400 acrylate polymers, poly(tert-butyl cyclohexyl acrylate) was selected for its biofilm- and encrustation-resistant properties. When combined with the swarming inhibitory poly(2-hydroxy-3-phenoxypropyl acrylate), the copolymer retained the bioinstructive properties of the respective homopolymers when challenged with Proteus mirabilis, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. Urinary tract catheterization causes the release of host proteins that are exploited by pathogens to colonize catheters. After preconditioning the copolymer with urine collected from patients before and after catheterization, reduced host fibrinogen deposition was observed, and resistance to diverse uropathogens was maintained. These data highlight the potential of the copolymer as a urinary catheter coating for preventing CAUTIs.}, }
@article {pmid36696490, year = {2023}, author = {Xiu, W and Ren, L and Xiao, H and Zhang, Y and Wang, D and Yang, K and Wang, S and Yuwen, L and Li, X and Dong, H and Li, Q and Mou, Y and Zhang, Y and Yin, Z and Liang, B and Gao, Y and Wang, L}, title = {Ultrasound-responsive catalytic microbubbles enhance biofilm elimination and immune activation to treat chronic lung infections.}, journal = {Science advances}, volume = {9}, number = {4}, pages = {eade5446}, doi = {10.1126/sciadv.ade5446}, pmid = {36696490}, issn = {2375-2548}, abstract = {Efficient treatment of chronic lung infections caused by Pseudomonas aeruginosa biofilms is a great challenge because of drug tolerance and immune evasion issues. Here, we develop ultrasound-responsive catalytic microbubbles with biofilm elimination and immune activation properties to combat chronic lung infection induced by P. aeruginosa biofilms. In these microbubbles, piperacillin and Fe3O4 nanoparticles form a drug-loaded shell surrounding the air core. Under ultrasound stimulation, the microbubbles can physically disrupt the structure of biofilms and enhance the penetration of both Fe3O4 nanoparticles and piperacillin into the biofilm. Then, Fe3O4 nanoparticles chemically degrade the biofilm matrix and kill the bacteria with the assistance of piperacillin. Fe3O4 nanoparticles can activate the immune response for biofilm elimination by polarizing macrophages into a pro-inflammatory phenotype. These ultrasound-responsive catalytic microbubbles efficiently treat chronic lung infections in a mouse model by combining physical/chemical/antibiotic biofilm elimination and immune activation, thus providing a promising strategy for combating bacterial biofilm infections.}, }
@article {pmid36696432, year = {2023}, author = {Cravener, MV and Do, E and May, G and Zarnowski, R and Andes, DR and McManus, CJ and Mitchell, AP}, title = {Reinforcement amid genetic diversity in the Candida albicans biofilm regulatory network.}, journal = {PLoS pathogens}, volume = {19}, number = {1}, pages = {e1011109}, doi = {10.1371/journal.ppat.1011109}, pmid = {36696432}, issn = {1553-7374}, abstract = {Biofilms of the fungal pathogen Candida albicans include abundant long filaments called hyphae. These cells express hypha-associated genes, which specify diverse virulence functions including surface adhesins that ensure biofilm integrity. Biofilm formation, virulence, and hypha-associated gene expression all depend upon the transcription factor Efg1. This transcription factor has been characterized extensively in the C. albicans type strain SC5314 and derivatives, but only recently has its function been explored in other clinical isolates. Here we define a principal set of Efg1-responsive genes whose expression is significantly altered by an efg1Δ/Δ mutation across 17 clinical isolates. This principal gene set includes 68 direct Efg1 targets, whose 5' regions are bound by Efg1 in five clinical isolates, and 42 indirect Efg1 targets, whose 5' regions are not detectably bound by Efg1. Three direct Efg1 target genes encode transcription factors-BRG1, UME6, and WOR3 -whose increased expression in an efg1Δ/Δ mutant restores expression of multiple indirect and direct principal targets, as well as biofilm formation ability. Although BRG1 and UME6 are well known positive regulators of hypha-associated genes and biofilm formation, WOR3 is best known as an antagonist of Efg1 in the sexual mating pathway. We confirm the positive role of WOR3 in biofilm formation with the finding that a wor3Δ/Δ mutation impairs biofilm formation in vitro and in an in vivo biofilm model. Positive control of Efg1 direct target genes by other Efg1 direct target genes-BRG1, UME6, and WOR3 -may buffer principal Efg1-responsive gene expression against the impact of genetic variation in the C. albicans species.}, }
@article {pmid36695920, year = {2023}, author = {Tambassi, M and Passarini, E and Menozzi, I and Berni, M and Bracchi, C and Dodi, A and Bolzoni, L and Scaltriti, E and Morganti, M and Ferrarini, G and Sordi, L and Sarti, M and Ambretti, S and Pongolini, S}, title = {Klebsiella pneumoniae carrying multiple alleles of antigen 43-encoding gene of Escherichia coli associated with biofilm formation.}, journal = {European journal of clinical microbiology &amp; infectious diseases : official publication of the European Society of Clinical Microbiology}, volume = {}, number = {}, pages = {}, pmid = {36695920}, issn = {1435-4373}, abstract = {A clinical strain of Klebsiella pneumoniae typed as sequence type 307 carrying three different alleles of the flu gene encoding the Escherichia coli virulence factor antigen 43 associated with biofilm formation was detected and characterized. The flu alleles are located in the chromosome inside putative integrative conjugative elements. The strain displays the phenotypes associated with Ag43, i.e. bi-phasic colony morphology and enhanced biofilm production. Furthermore, the strain produces low amount of capsule known to affect Ag43 function. Analysis of 1431 worldwide deposited genomes revealed that 3.7% Klebsiella pneumoniae carry one or two flu alleles.}, }
@article {pmid36694584, year = {2022}, author = {Radwan, AA and Darwesh, OM and Emam, MT and Mohamed, KA and Shady, HMA}, title = {A combined treatment of Proteinase K and biosynthesized ZnO-NPs for eradication of dairy biofilm of sporeformers.}, journal = {AIMS microbiology}, volume = {8}, number = {4}, pages = {507-527}, pmid = {36694584}, issn = {2471-1888}, abstract = {Biofilms of sporeformers found in the dairy industry are the major contaminants during processing, as they withstand heat and chemical treatment that are used to control microbes. The present work is aimed to remove these resistant forms of bacterial community (biofilm) present in dairy production lines using ecofriendly agents based on proteinase K (Prot-K) coupled with Zinc oxide nanoparticles (ZnO-NPs). Some metal/metal oxide (Ag, CuO and ZnO) NPs were prepared microbially, and ZnO-NPs were characterized as the most effective ones among them. The produced ZnO-NPs were 15-25 nm in size with spherical shape, and FTIR analysis confirmed the presence of proteins and alkanes surrounding particles as capping agents. Application of Prot-K for eradication (removal) of a model biofilm of mixed sporeformers on food-grade stainless steel resulted in an 83% reduction in the absorbance of crystal violet-stained biofilm. When Prot-K was mixed with the biosynthesized NPs ZnO_G240, the reduction increased to 99.19%. This finding could contribute to an efficient cleaning approach combined with CIP to remove the recalcitrant biofilms in dairy production lines.}, }
@article {pmid36691521, year = {2023}, author = {Pham, LHP and Ly, KL and Colon-Ascanio, M and Ou, J and Wang, H and Lee, SW and Wang, Y and Choy, JS and Phillips, KS and Luo, X}, title = {Dissolvable alginate hydrogel-based biofilm microreactors for antibiotic susceptibility assays.}, journal = {Biofilm}, volume = {5}, number = {}, pages = {100103}, pmid = {36691521}, issn = {2590-2075}, abstract = {Biofilms are found in many infections in the forms of surface-adhering aggregates on medical devices, small clumps in tissues, or even in synovial fluid. Although antibiotic resistance genes are studied and monitored in the clinic, the structural and phenotypic changes that take place in biofilms can also lead to significant changes in how bacteria respond to antibiotics. Therefore, it is important to better understand the relationship between biofilm phenotypes and resistance and develop approaches that are compatible with clinical testing. Current methods for studying antimicrobial susceptibility are mostly planktonic or planar biofilm reactors. In this work, we develop a new type of biofilm reactor-three-dimensional (3D) microreactors-to recreate biofilms in a microenvironment that better mimics those in vivo where bacteria tend to form surface-independent biofilms in living tissues. The microreactors are formed on microplates, treated with antibiotics of 1000 times of the corresponding minimal inhibitory concentrations (1000 × MIC), and monitored spectroscopically with a microplate reader in a high-throughput manner. The hydrogels are dissolvable on demand without the need for manual scraping, thus enabling measurements of phenotypic changes. Bacteria inside the biofilm microreactors are found to survive exposure to 1000 × MIC of antibiotics, and subsequent comparison with plating results reveals no antibiotic resistance-associated phenotypes. The presented microreactor offers an attractive platform to study the tolerance and antibiotic resistance of surface-independent biofilms such as those found in tissues.}, }
@article {pmid36690856, year = {2023}, author = {Pápai, M and Benedek, T and Táncsics, A and Bornemann, TLV and Plewka, J and Probst, AJ and Hussein, D and Maróti, G and Menashe, O and Kriszt, B}, title = {Selective enrichment, identification, and isolation of diclofenac, ibuprofen, and carbamazepine degrading bacteria from a groundwater biofilm.}, journal = {Environmental science and pollution research international}, volume = {}, number = {}, pages = {}, pmid = {36690856}, issn = {1614-7499}, abstract = {Diclofenac, ibuprofen, and carbamazepine are three of the most widely detected and most concerning pharmaceutical residues in aquatic ecosystems. The aim of this study was to identify bacteria that may be involved in their degradation from a bacterial biofilm. Selective enrichment cultures in mineral salt solution containing pharmaceutical compounds as sole source of carbon and energy were set up, and population dynamics were monitored using shotgun metagenome sequencing. Bacterial genomes were reconstructed using genome-resolved metagenomics. Thirty bacterial isolates were obtained, identified at species level, and tested regarding pharmaceutical biodegradation at an initial concentration of 1.5 mg l[-1]. The results indicated that most probably diclofenac biodegrading cultures consisted of members of genera Ferrovibrio, Hydrocarboniphaga, Zavarzinia, and Sphingopyxis, while in ibuprofen biodegradation Nocardioides and Starkeya, and in carbamazepine biodegradation Nocardioides, Pseudonocardia, and Sphingopyxis might be involved. During the enrichments, compared to the initial state the percentage relative abundance of these genera increased up to three orders of magnitude. Except Starkeya, the genomes of these bacteria were reconstructed and annotated. Metabolic analyses of the annotated genomes indicated that these bacteria harbored genes associated with pharmaceutical biodegradation. Stenotrophomonas humi DIC_5 and Rhizobium daejeonense IBU_18 isolates eliminated diclofenac and ibuprofen during the tests in the presence of either glucose (3 g l[-1]) or in R2A broth. Higher than 90% concentration reduction was observed in the case of both compounds.}, }
@article {pmid36690667, year = {2023}, author = {Sugimoto, S and Kinjo, Y}, title = {Instantaneous Clearing of Biofilm (iCBiofilm): an optical approach to revisit bacterial and fungal biofilm imaging.}, journal = {Communications biology}, volume = {6}, number = {1}, pages = {38}, pmid = {36690667}, issn = {2399-3642}, abstract = {Whole-biofilm imaging at single-cell resolution is necessary for system-level analysis of cellular heterogeneity, identification of key matrix component functions and response to immune cells and antimicrobials. To this end, we developed a whole-biofilm clearing and imaging method, termed instantaneous clearing of biofilm (iCBiofilm). iCBiofilm is a simple, rapid, and efficient method involving the immersion of biofilm samples in a refractive index-matching medium, enabling instant whole-biofilm imaging with confocal laser scanning microscopy. We also developed non-fixing iCBiofilm, enabling live and dynamic imaging of biofilm development and actions of antimicrobials. iCBiofilm is applicable for multicolor imaging of fluorescent proteins, immunostained matrix components, and fluorescence labeled cells in biofilms with a thickness of several hundred micrometers. iCBiofilm is scalable from bacterial to fungal biofilms and can be used to observe biofilm-neutrophil interactions. iCBiofilm therefore represents an important advance for examining the dynamics and functions of biofilms and revisiting bacterial and fungal biofilm formation.}, }
@article {pmid36690637, year = {2023}, author = {Hemdan, BA and El-Taweel, GE and Naha, S and Goswami, P}, title = {Bacterial community structure of electrogenic biofilm developed on modified graphite anode in microbial fuel cell.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {1255}, pmid = {36690637}, issn = {2045-2322}, abstract = {Formation of electrogenic microbial biofilm on the electrode is critical for harvesting electrical power from wastewater in microbial biofuel cells (MFCs). Although the knowledge of bacterial community structures in the biofilm is vital for the rational design of MFC electrodes, an in-depth study on the subject is still awaiting. Herein, we attempt to address this issue by creating electrogenic biofilm on modified graphite anodes assembled in an air-cathode MFC. The modification was performed with reduced graphene oxide (rGO), polyaniline (PANI), and carbon nanotube (CNTs) separately. To accelerate the growth of the biofilm, soybean-potato composite (plant) powder was blended with these conductive materials during the fabrication of the anodes. The MFC fabricated with PANI-based anode delivered the current density of 324.2 mA cm[-2], followed by CNTs (248.75 mA cm[-2]), rGO (193 mA cm[-2]), and blank (without coating) (151 mA cm[-2]) graphite electrodes. Likewise, the PANI-based anode supported a robust biofilm growth containing maximum bacterial cell densities with diverse shapes and sizes of the cells and broad metabolic functionality. The alpha diversity of the biofilm developed over the anode coated with PANI was the loftiest operational taxonomic unit (2058 OUT) and Shannon index (7.56), as disclosed from the high-throughput 16S rRNA sequence analysis. Further, within these taxonomic units, exoelectrogenic phyla comprising Proteobacteria, Firmicutes, and Bacteroidetes were maximum with their corresponding level (%) 45.5, 36.2, and 9.8. The relative abundance of Gammaproteobacteria, Clostridia, and Bacilli at the class level, while Pseudomonas, Clostridium, Enterococcus, and Bifidobacterium at the genus level were comparatively higher in the PANI-based anode.}, }
@article {pmid36690218, year = {2023}, author = {Dong, K and Qiu, Y and Wang, X and Yu, D and Yu, Z and Feng, J and Wang, J and Gu, R and Zhao, J}, title = {Towards low carbon demand and highly efficient nutrient removal: establishing denitrifying phosphorus removal in a biofilm-based system.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {128658}, doi = {10.1016/j.biortech.2023.128658}, pmid = {36690218}, issn = {1873-2976}, abstract = {The combined denitrifying phosphorus removal (DPR) and Anammox process is expected to achieve advanced nutrient removal with low carbon consumption. However, exchanging ammonia/nitrate between them is one limitation. This study investigated the feasibility of conducting DPR in a biofilm reactor to solve that problem. After 46-day anaerobic/aerobic operation, high phosphorus removal efficiency (PRE, 83.15%) was obtained in the activated sludge (AS) and biofilm co-existed system, in which the AS performed better. Phosphate-accumulating organisms might quickly adapt to the anoxic introduced nitrate, but the following aerobic stage ensured a low effluent orthophosphate (< 1.03 mg/L). Because of waste sludge discharging and AS transforming to biofilm, the suspended solids dropped below 60 mg/L on Day 100, resulting in PRE decline (17.17%) and effluent orthophosphate rise (4.23 mg/L). Metagenomes analysis revealed that Pseudomonas and Thiothrix had genes for denitrification and encoding Pit phosphate transporter, and Candidatus_Competibacter was necessary for biofilm formation.}, }
@article {pmid36689842, year = {2023}, author = {Wang, W and Cao, Y and Li, J and Lu, S and Ge, H and Pan, S and Pan, X and Wang, L}, title = {The impact of osmotic stresses on the biofilm formation, immunodetection, and morphology of Aeromonas hydrophila.}, journal = {Microbiological research}, volume = {269}, number = {}, pages = {127301}, doi = {10.1016/j.micres.2023.127301}, pmid = {36689842}, issn = {1618-0623}, abstract = {Aeromonas hydrophila (Ah) is a zoonotic pathogen of great importance to aquaculture and human health. This study systematically evaluated the impact of salinity, sugar, ammonia nitrogen, and nitric nitrogen levels on the fitness of Ah by using Luria-Bertani (LB) broth supplemented with different concentrations of NaCl, sucrose, NH4Cl, urea, NaNO2 or NaNO3. Results showed that the static biofilm formation of Ah was higher at 28 °C compared to 37 °C (P < 0.05). At 28 °C, as the NaCl (>1 %) and sucrose levels increased, the Ah biofilm formation and the binding between Ah cells and monoclonal antibodies (mAbs, for immunodetection) decreased. Elevated ammonia nitrogen and nitric nitrogen levels generated no significant impact on Ah biofilm formation or immunodetection (P > 0.05). The expression of mAbs-targeted Omp remained unchanged under high NaCl or sucrose conditions. Further analysis showed that high sucrose conditions led to the over-expression of the extracellular polysaccharides (PS) and promoted the formation of capsule-like structures. These over-expressed PS and capsule structures might be one reason explaining the inhibited immunodetection efficacy. Results generated from this study provide crucial insights for the design of recovery and detection protocols for Ah present in food or environmental samples.}, }
@article {pmid36688769, year = {2023}, author = {Lorenzini, M and Cappello, MS and Andreolli, M and Zapparoli, G}, title = {Characterization of selected species of Pichia and Candida for their growth capacity in apple and grape must and their biofilm parameters.}, journal = {Letters in applied microbiology}, volume = {76}, number = {1}, pages = {}, doi = {10.1093/lambio/ovac028}, pmid = {36688769}, issn = {1472-765X}, abstract = {Pichia and Candida species include biofilm-forming yeasts able to spoil foods and beverages. Strains belonging to 10 Pichia and Candida species isolated from apples, grape musts, and wines were analysed. They were subjected to molecular typing and characterized for their ability to grow and ferment must for cider and wine production, and for their biofilm properties. All strains grew similarly in apple and grape must. Glucose-fermenting strains displayed differentiated fermentation performances. Great variation in SO2 and ethanol sensitivity was observed among the strains. Pichia manshurica strains showed high tolerance to both molecules. Eleven and five surface-spreading biofilm (MAT) phenotypes were identified in solid and liquid media, respectively. Strains produced biofilms with variable thicknesses and widths in culture tubes. Cell adherence and aqueous-hydrocarbon biphasic hydrophobicity assays were carried out. Some Pichia manshurica and P. membranifaciens strains exhibited a high capacity to form a thick biofilm and had high cell adherence and hydrophobicity values. These strains could be more likely to colonize the internal surfaces of tanks. This study evidenced that some Pichia and Candida strains can proliferate during apple and grape must fermentation and may be detrimental the beverage quality, due to their specific biofilm properties.}, }
@article {pmid36688748, year = {2023}, author = {Fernandes, MSM and Rios, JC and Vasconcelos, BM and Lourenço, MLMC and Matos, MNC and Cavalcante, RMB and de Almeida, MVA and Costa, RA and Carneiro, VA}, title = {Effect of Lactobacillus spp. cell-free supernatant against planktonic growth and biofilm formation of foodborne Escherichia coli isolates.}, journal = {Letters in applied microbiology}, volume = {76}, number = {1}, pages = {}, doi = {10.1093/lambio/ovac006}, pmid = {36688748}, issn = {1472-765X}, abstract = {The aim of this work was to evaluate the anti-Escherichia coli effect of cell-free supernatant (CFS) of Lactobacillus spp. against planktonic and biofilm forms of foodborne isolates. Escherichiacoli strains (P12, P25, P35 and P36), previously isolated from fresh filets of fish, were subjected to antimicrobial susceptibility determination by the disc-diffusion agar method. Subsequently, the antagonistic effect between probiotic and pathogenic strains was determined by spot overlay assay. Finally, the CFS activity against pre-established (12 h) biofilms was demonstrated through biomass quantification by crystal violet staining and scanning electron microscopy (SEM). All isolates presented some pattern of resistance, primarily to ampicillin and tetracycline. Probiotic strains presented high antagonistic effects against all E. coli strains, presenting inhibition zones (R) ranging from 15.60 to 20.67 mm. Additionally, the residual biomass of pre-established (12 h) biofilm was drastically reduced about 50% after CFS treatment (P < 0.01). What can be noted by SEM images, which show less surface-attached cells of CFS-treated biofilms of E. coli (P12). Thus, cell-free preparations produced from Lactobacillus spp. may represent a tool in the battle against planktonic cells and biofilm forms of antibiotic-resistant E. coli.}, }
@article {pmid36688105, year = {2023}, author = {Kumar, S and Nguyen, AT and Goswami, S and Ferracane, J and Koley, D}, title = {Real-Time Monitoring of Biofilm Formation Using a Noninvasive Impedance-Based Method.}, journal = {Sensors and actuators. B, Chemical}, volume = {376}, number = {Pt A}, pages = {}, pmid = {36688105}, issn = {0925-4005}, abstract = {Biofilms are complex three-dimensional microbial communities that adhere to a variety of surfaces and interact with their surroundings. Because of the dynamic nature of biofilm formation, establishing a uniform technique for quantifying and monitoring biofilm volume, shape, and features in real-time is challenging. Herein, we describe a noninvasive electrochemical impedance approach for real-time monitoring of dental plaque-derived multispecies biofilm growth on a range of substrates. A working equation relating electrochemical impedance to live biofilm volume has been developed that is applicable to all three surfaces examined, including glass, dental filling resin, and Ca[2+]-releasing resin composites. Impedance changes of 2.5, 35, 50, and 65% correlated to biofilm volumes of 0.10 ± 0.01, 16.9 ± 2.2, 29.7 ± 2.3, and 38.6 ± 2.8 μm[3]/μm[2], respectively. We discovered that glass, dental filling resin, and Ca[2+]-releasing dental composites required approximately 3.5, 4.5, and 6 days, respectively, to achieve a 50% change in impedance. The local pH change at the biofilm-substrate interfaces also monitored with potentiometry pH microsensor, and pH change varied according to biofilm volume. This impedance-based technique can be a useful analytical method for monitoring the growth of biofilms on a variety of substrates in real-time. Therefore, this technique may be beneficial for examining antibacterial properties of novel biomaterials.}, }
@article {pmid36687621, year = {2022}, author = {Li, X and Gu, N and Ye, Y and Lan, H and Peng, F and Peng, G}, title = {Intense pulsed light for inactivating planktonic and biofilm molds in food.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1104875}, pmid = {36687621}, issn = {1664-302X}, abstract = {It has been reported that about a quarter of the world's agriculture products is unable to be consumed each year because of mold contamination, resulting in incalculable economic losses. Despite modern food technology and the various preservation techniques available, the problem of mold contamination of food is still not adequately controlled. In this study, we simulated the biofilm formed by Aspergillus niger and Penicillium glaucum in liquid and solid food in 96 well cell culture plates and polycarbonate membrane models, respectively, and investigated the fungicidal effect of IPL on planktonic and biofilm molds at three different capacitance parameters at room and refrigerator temperatures. The results show that IPL can achieve fungicidal rates of over 99% for planktonic molds and over 90% for biofilm molds, and that the smaller the capacitance, the more frequent the irradiation required to achieve the same fungicidal rate. In addition, temperature, A. niger or Penicillium glaucum have no effect on the fungicidal effect of IPL. We believe that IPL is a promising non-thermal physical sterilization technique for fungal inhibition on food surfaces.}, }
@article {pmid36687584, year = {2022}, author = {Bisht, K and Luecke, AR and Wakeman, CA}, title = {Temperature-specific adaptations and genetic requirements in a biofilm formed by Pseudomonas aeruginosa.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1032520}, pmid = {36687584}, issn = {1664-302X}, abstract = {Pseudomonas aeruginosa is a gram-negative opportunistic pathogen often associated with nosocomial infections that are made more severe by this bacterium's ability to form robust biofilms. A biofilm is a microbial community encompassing cells embedded within an extracellular polymeric substrate (EPS) matrix that is typically secreted by the encased microbial cells. Biofilm formation is influenced by several environmental cues, and temperature fluctuations are likely to be an important stimulus in the lifecycle of P. aeruginosa as it transitions between life in aquatic or soil environments to sites of infection in the human host. Previous work has demonstrated that human body temperature can induce a shift in the biofilm EPS relative to room temperature growth, resulting in an incorporation of a filamentous phage coat protein into the biofilm EPS. In this study, we sought to identify adaptations enabling biofilm formation at room temperature or temperatures mimicking the natural environment of P. aeruginosa (23°C and 30°C) relative to temperatures mimicking life in the human host (37°C and 40°C). We identified higher biofilm: biomass ratios at lower temperatures on certain substrates, which correlated with a higher relative abundance of apparent polysaccharide EPS content. However, the known genes for EPS polysaccharide production in P. aeruginosa PA14 did not appear to be specifically important for temperature-dependent biofilm adaptation, with the pelB gene appearing to be generally important and the algD gene being generally expendable in all conditions tested. Instead, we were able to identify two previously uncharacterized hypothetical proteins (PA14_50070 and PA14_67550) specifically required for biofilm formation at 23°C and/or 30°C relative to temperatures associated with the human host. These unstudied contributors to biofilm integrity may have been previously overlooked since most P. aeruginosa biofilm studies tend to use 37°C growth temperatures. Overall, our study demonstrates that temperature shifts can have dramatic impacts on biofilm structure and highlights the importance of studying environment-specific adaptations in biofilm physiology.}, }
@article {pmid36687169, year = {2023}, author = {Yamaguchi-Kuroda, Y and Kikuchi, Y and Kokubu, E and Ishihara, K}, title = {Porphyromonas gingivalis diffusible signaling molecules enhance Fusobacterium nucleatum biofilm formation via gene expression modulation.}, journal = {Journal of oral microbiology}, volume = {15}, number = {1}, pages = {2165001}, pmid = {36687169}, issn = {2000-2297}, abstract = {BACKGROUND: Periodontitis is caused by a dysbiotic shift in the dental plaque microbiome. Fusobacterium nucleatum is involved in the colonization of Porphyromonas gingivalis, which plays a key role in dysbiosis, via coaggregation and synergy with this microorganism.<br><br>AIM: We investigated the effect of diffusible signaling molecules from P. gingivalis ATCC 33277 on F. nucleatum TDC 100 to elucidate the synergistic mechanisms involved in dysbiosis.<br><br>METHODS: The two species were cocultured separated with an 0.4-&#xb5;m membrane in tryptic soy broth, and F. nucleatum gene expression profiles in coculture with P. gingivalis were compared with those in monoculture.<br><br>RESULTS: RNA sequencing revealed 139 genes differentially expressed between the coculture and monoculture. The expression of 52 genes was upregulated, including the coaggregation ligand-coding gene. Eighty-seven genes were downregulated. Gene Ontology analysis indicated enrichment for the glycogen synthesis pathway and a decrease in de novo synthesis of purine and pyrimidine.<br><br>CONCLUSION: These results indicate that diffusible signaling molecules from P. gingivalis induce metabolic changes in F. nucleatum, including an increase in polysaccharide synthesis and reduction in de novo synthesis of purine and pyrimidine. The metabolic changes may accelerate biofilm formation by F. nucleatum with P. gingivalis. Further, the alterations may represent potential therapeutic targets for preventing dysbiosis.}, }
@article {pmid36685419, year = {2023}, author = {Tiwari, M and Panwar, S and Tiwari, V}, title = {Assessment of potassium ion channel during electric signalling in biofilm formation of Acinetobacter baumannii for finding antibiofilm molecule.}, journal = {Heliyon}, volume = {9}, number = {1}, pages = {e12837}, pmid = {36685419}, issn = {2405-8440}, abstract = {Acinetobacter baumannii is an opportunistic ESKAPE pathogen which causes nosocomial infections and can produce biofilms that act as resistant determinants. The role of quorum sensing (chemical signaling) in biofilm establishment has already been studied extensively, but the existence of electrochemical signaling during biofilm formation by A. baumannii has not yet been investigated. The current study evaluated the presence of electrical signaling, types of ion channels involved, and their role in biofilm formation using spectroscopic and microbiological methods. The findings suggest that the potassium ion channel has a significant role in the electrical signaling during the biofilm formation by A. baumannii. Further, in-silico screening, molecular mechanics, and molecular dynamic simulation studies identify a potential lead, ZINC12496555(a specific inhibitor), which targets the potassium ion channel protein of A. baumannii. Mutational analysis of the interacting residues showed alterations in the unfolding rate of this protein after the selected mutation, which shows its role in the stability of this protein. It was also observed that identified lead has high antibiofilm activity, no human off-targets, and non-cytotoxicity to cell lines. Thus, identified lead against the potassium channel of A baumannii may be used as an effective therapeutic for the treatment of A. baumannii infections after further experimental validation.}, }
@article {pmid36681348, year = {2023}, author = {Paniguel Oliveira, E and Giordani, A and Kawanishi, J and Syrto Octavio de Souza, T and Okada, DY and Brucha, G and Brito de Moura, R}, title = {Biofilm stratification and autotrophic-heterotrophic interactions in a structured bed reactor (SBRIA) for carbon and nitrogen removal.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {128639}, doi = {10.1016/j.biortech.2023.128639}, pmid = {36681348}, issn = {1873-2976}, abstract = {The structured-bed reactor with intermittent aeration (SBRIA) is a promising technology for simultaneous carbon and nitrogen removal from wastewater. An in depth understanding of the microbiological in the reactor is crucial for its optimization. In this research, biofilm samples from the aerobic and anoxic zones of an SBRIA were analyzed through 16S rRNA sequencing to evaluate the bacterial community shift with variations in the airflow and aeration time. The control of the airflow and aeration time were essential to guarantee reactor performances to nitrogen removal close to 80%, as it interfered in nitrifying and denitrifying communities. The aeration time of 1.75 h led to establishment of different nitrogen removal pathways by syntrophic relationships between nitrifier, denitrifier and anammox species. Additionally, the predominance of these different species in the internal and external parts of the biofilm varied according to the airflow.}, }
@article {pmid36681347, year = {2023}, author = {Saidulu, D and Srivastava, A and Kumar Gupta, A}, title = {Elucidating the performance of integrated anoxic/oxic moving bed biofilm reactor: Assessment of organics and nutrients removal and optimization using feed forward back propagation neural network.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {128641}, doi = {10.1016/j.biortech.2023.128641}, pmid = {36681347}, issn = {1873-2976}, abstract = {A lab-scale integrated anoxic and oxic (A/O) moving bed biofilm reactor (MBBR) was investigated for the removal of organics and nutrients by varying chemical oxygen demand (COD) to NH4-N ratio (C/N ratio: 3.5, 6.75, and 10), hydraulic retention time (HRT: 6 h, 15 h, and 24 h), and recirculation ratio (R: 1, 2, and 3). The use of activated carbon coated carriers prepared from waste polyethylene material and polyurethane sponges attached to a cylindrical frame in the integrated A/O MBBR increased the attached growth biomass significantly. More than 95% of COD removal was observed under the C/N ratio of 10 at an HRT of 24 h. While the low C/N ratio favored the removal of NH4-N (∼98%) and PO4[3-]-P (∼90%) with an optimal R of 1.75. Using the experimental dataset, to predict and forecast the performance of integrated A/O MBBR, a feed-forward-backpropagation-neural-network model was developed.}, }
@article {pmid36679198, year = {2023}, author = {Zhang, Y and Ge, T and Li, Y and Lu, J and Du, H and Yan, L and Tan, H and Li, J and Yin, Y}, title = {Anti-Fouling and Anti-Biofilm Performance of Self-Polishing Waterborne Polyurethane with Gemini Quaternary Ammonium Salts.}, journal = {Polymers}, volume = {15}, number = {2}, pages = {}, doi = {10.3390/polym15020317}, pmid = {36679198}, issn = {2073-4360}, abstract = {Biofilms are known to be difficult to eradicate and control, complicating human infections and marine biofouling. In this study, self-polishing and anti-fouling waterborne polyurethane coatings synthesized from gemini quaternary ammonium salts (GQAS), polyethylene glycol (PEG), and polycaprolactone diol (PCL) demonstrate excellent antibiofilm efficacy. Their anti-fouling and anti-biofilm performance was confirmed by a culture-based method in broth media, with the biofilm formation factor against Gram-positive (S. aureus) and Gram-negative bacterial strains (E. coli) for 2 days. The results indicate that polyurethane coatings have excellent anti-biofilm activity when the content of GQAS reached 8.5 wt% against S. aureus, and 15.8 wt% against E. coli. The resulting waterborne polyurethane coatings demonstrate both hydrolytic and enzymatic degradation, and the surface erosion enzymatic degradation mechanism enables them with good self-polishing capability. The extracts cyto-toxicity of these polyurethane coatings and degradation liquids was also systematically studied; they could be degraded to non-toxic or low toxic compositions. This study shows the possibility to achieve potent self-polishing and anti-biofilm efficacy by integrating antibacterial GQAS, PEG, and PCL into waterborne polyurethane coatings.}, }
@article {pmid36678928, year = {2023}, author = {Arenas-Vivo, A and Celis Arias, V and Amariei, G and Rosal, R and Izquierdo-Barba, I and Hidalgo, T and Vallet-Regí, M and Beltrán, HI and Loera-Serna, S and Horcajada, P}, title = {Antiadherent AgBDC Metal-Organic Framework Coating for Escherichia coli Biofilm Inhibition.}, journal = {Pharmaceutics}, volume = {15}, number = {1}, pages = {}, doi = {10.3390/pharmaceutics15010301}, pmid = {36678928}, issn = {1999-4923}, abstract = {Surface microbial colonization and its potential biofilm formation are currently a major unsolved problem, causing almost 75% of human infectious diseases. Pathogenic biofilms are capable of surviving high antibiotic doses, resulting in inefficient treatments and, subsequently, raised infection prevalence rates. Antibacterial coatings have become a promising strategy against the biofilm formation in biomedical devices due to their biocidal activity without compromising the bulk material. Here, we propose for the first time a silver-based metal-organic framework (MOF; here denoted AgBDC) showing original antifouling properties able to suppress not only the initial bacterial adhesion, but also the potential surface contamination. Firstly, the AgBDC stability (colloidal, structural and chemical) was confirmed under bacteria culture conditions by using agar diffusion and colony counting assays, evidencing its biocide effect against the challenging E. coli, one of the main representative indicators of Gram-negative resistance bacteria. Then, this material was shaped as homogeneous spin-coated AgBDC thin film, investigating its antifouling and biocide features using a combination of complementary procedures such as colony counting, optical density or confocal scanning microscopy, which allowed to visualize for the first time the biofilm impact generated by MOFs via a specific fluorochrome, calcofluor.}, }
@article {pmid36678466, year = {2023}, author = {Khalid, A and Cookson, AR and Whitworth, DE and Beeton, ML and Robins, LI and Maddocks, SE}, title = {A Synthetic Polymicrobial Community Biofilm Model Demonstrates Spatial Partitioning, Tolerance to Antimicrobial Treatment, Reduced Metabolism, and Small Colony Variants Typical of Chronic Wound Biofilms.}, journal = {Pathogens (Basel, Switzerland)}, volume = {12}, number = {1}, pages = {}, doi = {10.3390/pathogens12010118}, pmid = {36678466}, issn = {2076-0817}, abstract = {Understanding chronic wound infection is key for successful treatment and requires accurate laboratory models. We describe a modified biofilm flow device that effectively mimics the chronic wound environment, including simulated wound fluid, a collagen-based 3D biofilm matrix, and a five-species mixture of clinically relevant bacteria (Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, and Citrobacter freundii). Mixed biofilms were cultured for between 3 and 14 days with consistent numbers of bacteria that exhibited reduced metabolic activity, which increased with a high dose of glucose. S. aureus was recovered from biofilms as a small colony variant, but as a normal colony variant if P. aeruginosa was excluded from the system. Bacteria within the biofilm did not co-aggregate but formed discrete, species-specific clusters. Biofilms demonstrated differential tolerance to the topical antimicrobials Neosporin and HOCl, consistent with protection due to the biofilm lifestyle. The characteristics exhibited within this model match those of real-world wound biofilms, reflecting the clinical scenario and yielding a powerful in vitro tool that is versatile, inexpensive, and pivotal for understanding chronic wound infection.}, }
@article {pmid36678381, year = {2022}, author = {Khalil, MA and Alorabi, JA and Al-Otaibi, LM and Ali, SS and Elsilk, SE}, title = {Antibiotic Resistance and Biofilm Formation in Enterococcus spp. Isolated from Urinary Tract Infections.}, journal = {Pathogens (Basel, Switzerland)}, volume = {12}, number = {1}, pages = {}, doi = {10.3390/pathogens12010034}, pmid = {36678381}, issn = {2076-0817}, abstract = {BACKGROUND: A urinary tract infection (UTI) resulting from multidrug-resistant (MDR) enterococci is a common disease with few therapeutic options. About 15% of urinary tract infections are caused by biofilm-producing Enterococcus spp. Therefore, the objective of this study was to identify the MDR enterococci associated with UTIs and assess their potential to produce biofilms.<br><br>METHODS: Thirty Enterococcus isolates were obtained from urine samples collected from UTI patients at King Abdulaziz Specialist Hospital in Taif, Saudi Arabia. The antimicrobial resistance profiles of the isolates were evaluated using disk diffusion techniques against 15 antimicrobial agents. Two techniques, Congo red agar (CRA) and a microtiter plate (MTP), were used to assess the potential of the isolates to produce biofilms. The enterococcal isolates were screened for biofilm-related genes, esp; ebpA; and ebpB, using the PCR method.<br><br>RESULTS: The molecular identification of the collected bacteria revealed the presence of 73.3% Enterococcus&amp;nbsp;faecalis and 26.6% Enterococcus&amp;nbsp;faecium. The antibiotic susceptibility test revealed that all the tested Enterococcus spp. were resistant to all antimicrobials except for linezolid and tigecycline. Additionally, by employing the CRA and MTP techniques, 76.6% and 100% of the Enterococcus isolates were able to generate biofilms, respectively. In terms of the association between the antibiotic resistance and biofilm's formation, it was observed that isolates capable of creating strong biofilms were extremely resistant to most of the antibiotics tested. The obtained data showed that all the tested isolates had biofilm-encoding genes.<br><br>CONCLUSIONS: Our research revealed that the biofilm-producing enterococci bacteria that causes urinary tract infections were resistant to antibiotics. Therefore, it is necessary to seek other pharmacological treatments if antibiotic medicine fails.}, }
@article {pmid36678375, year = {2022}, author = {Sulaiman, R and Trizna, E and Kolesnikova, A and Khabibrakhmanova, A and Kurbangalieva, A and Bogachev, M and Kayumov, A}, title = {Antimicrobial and Biofilm-Preventing Activity of l-Borneol Possessing 2(5H)-Furanone Derivative F131 against S. aureus-C.&amp;nbsp;albicans Mixed Cultures.}, journal = {Pathogens (Basel, Switzerland)}, volume = {12}, number = {1}, pages = {}, doi = {10.3390/pathogens12010026}, pmid = {36678375}, issn = {2076-0817}, abstract = {Candida albicans and Staphylococcus aureus are human pathogens that are able to form mixed biofilms on the surface of mucous membranes, implants and catheters. In biofilms, these pathogens have increased resistance to antimicrobials, leading to extreme difficulties in the treatment of mixed infections. The growing frequency of mixed infections caused by S. aureus and C. albicans requires either the development of new antimicrobials or the proposal of alternative approaches to increase the efficiency of conventional ones. Here, we show the antimicrobial, biofilm-preventing and biofilm-eradicating activity of 2(5H)-furanone derivative F131, containing an l-borneol fragment against S. aureus-C. albicans mixed biofilms. Furanone F131 is also capable of inhibiting the formation of monospecies and mixed biofilms by S. aureus and C. albicans. The minimal biofilm-prevention concentration (MBPC) of this compound was 8-16 μg/mL for S. aureus and C. albicans mono- and two-species biofilms. While the compound demonstrates slightly lower activity compared to conventional antimicrobials (gentamicin, amikacin, fluconazole, terbinafine and benzalkonium chloride), F131 also increases the antimicrobial activity of fluconazole-gentamicin and benzalkonium chloride against mixed biofilms of S. aureus-C. albicans, thus reducing MBPC of fluconazole-gentamicin by 4-16 times and benzalkonium chloride twofold. F131 does not affect the transcription of the MDR1, CDR1 and CDR2 genes, thus suggesting a low risk of micromycete resistance to this compound. Altogether, combined use of antibiotics with a F131 could be a promising option to reduce the concentration of fluconazole used in antiseptic compositions and reduce the toxic effect of benzalkonium chloride and gentamicin. This makes them an attractive starting point for the development of alternative antimicrobials for the treatment of skin infections caused by S. aureus-C. albicans mixed biofilms.}, }
@article {pmid36677463, year = {2023}, author = {Smitran, A and Lukovic, B and Bozic, L and Jelic, D and Jovicevic, M and Kabic, J and Kekic, D and Ranin, J and Opavski, N and Gajic, I}, title = {Carbapenem-Resistant Acinetobacter baumannii: Biofilm-Associated Genes, Biofilm-Eradication Potential of Disinfectants, and Biofilm-Inhibitory Effects of Selenium Nanoparticles.}, journal = {Microorganisms}, volume = {11}, number = {1}, pages = {}, doi = {10.3390/microorganisms11010171}, pmid = {36677463}, issn = {2076-2607}, abstract = {This study aimed to investigate the biofilm-production ability of carbapenem-resistant Acinetobacter baumannii (CRAB), the biofilm-eradication potential of 70% ethanol and 0.5% sodium hypochlorite, the effects of selenium nanoparticles (SeNPs) against planktonic and biofilm-embedded CRAB, and the relationship between biofilm production and bacterial genotypes. A total of 111 CRAB isolates were tested for antimicrobial susceptibility, biofilm formation, presence of the genes encoding carbapenemases, and biofilm-associated virulence factors. The antibiofilm effects of disinfectants and SeNPs against CRAB isolates were also tested. The vast majority of the tested isolates were biofilm producers (91.9%). The bap, ompA, and csuE genes were found in 57%, 70%, and 76% of the CRAB isolates, with the csuE being significantly more common among biofilm producers (78.6%) compared to non-biofilm-producing CRAB (25%). The tested disinfectants showed a better antibiofilm effect on moderate and strong biofilm producers than on weak producers (p < 0.01). The SeNPs showed an inhibitory effect against all tested planktonic (MIC range: 0.00015 to >1.25 mg/mL) and biofilm-embedded CRAB, with a minimum biofilm inhibitory concentration of less than 0.15 mg/mL for 90% of biofilm producers. In conclusion, SeNPs might be used as promising therapeutic and medical device coating agents, thus serving as an alternative approach for the prevention of biofilm-related infections.}, }
@article {pmid36677395, year = {2022}, author = {AboElmaaty, SA and Shati, AA and Alfaifi, MY and Elbehairi, SEI and Sheraba, NS and Hassan, MG and Badawy, MSEM and Ghareeb, A and Hamed, AA and Gabr, EZ}, title = {Biofilm Inhibitory Activity of Actinomycete-Synthesized AgNPs with Low Cytotoxic Effect: Experimental and In Silico Study.}, journal = {Microorganisms}, volume = {11}, number = {1}, pages = {}, doi = {10.3390/microorganisms11010102}, pmid = {36677395}, issn = {2076-2607}, abstract = {The emergence of resistance by biofilm-forming bacteria has reached alarming and dangerous levels that threaten human civilization. The current study sought to investigate the antibiofilm potential of green-synthesized silver nanoparticles, mediated by a new Streptomyces strain. Zeta potential, transmission electron microscopy (TEM), and UV-Vis spectroscopy were used to analyze the biosynthesized AgNPs. Results revealed that silver nanoparticles had a size of (5.55 and 45.00 nm) nm and a spherical shape, with surface plasmon resonance (SPR) absorption at 400-460 nm in the UV-vis spectra establishing the formation of Streptomyces-Ag-NPs. The biosynthesized AgNPs showed a pronounced antibacterial efficacy against Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, and Staphylococcus aureus. Moreover, the obtained Streptomyces-AgNPs exerted biofilm inhibition activity against nosocomial hospital-resistant bacteria, including Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. The mechanism of biogenic AgNPs antibacterial action was visualized using TEM, which indicated the AgNPs accumulation and disruption of bacterial cell membrane function. Additionally, a molecular docking study was conducted to evaluate the binding mode of AgNPs with an Escherichia coli outer membrane. Furthermore, the cytotoxic profile of the AgNPs was evaluated toward three cell lines (MCF-7, HepG2 &amp; HCT 116), and the low cytotoxic effects of the obtained nanoparticles indicated their possible medical application with low risks to human health.}, }
@article {pmid36677381, year = {2022}, author = {Chi, SI and Ramirez-Arcos, S}, title = {Staphylococcal Enterotoxins Enhance Biofilm Formation by Staphylococcus aureus in Platelet Concentrates.}, journal = {Microorganisms}, volume = {11}, number = {1}, pages = {}, doi = {10.3390/microorganisms11010089}, pmid = {36677381}, issn = {2076-2607}, abstract = {Biofilm formation and slow growth by Staphylococcus aureus in platelet concentrates (PCs) cause missed detection of this bacterium during routine PC screening with automated culture systems. This heightens the chances of false-negative screening transfusions and pre-disposes transfusion patients to an elevated risk of sepsis due to secretion of staphylococcal enterotoxins (SEs) in PCs. A hybrid approach of comparative RNAseq analyses and CRISPR mutagenesis of SE genes was employed to investigate the effect of SEs in S. aureus growth and biofilm formation in PCs. RNAseq data showed no differential expression for key biofilm genes, whereas SE genes were upregulated (>0.5- to 3.6-fold change) in PCs compared to trypticase soy broth (TSB). Remarkably, growth and biofilm formation assays revealed increased growth for the S. aureus SE mutants, while their ability to form biofilms was significantly impaired (-6.8- to -2.4-fold change) in comparison to the wild type strain, in both PCs and TSB. Through the well-established superantigen mechanism of SEs, we propose three roles for SEs during biofilm development in PCs: (1) provide a scaffold for biofilm matrix, (2) mediate cell-to-cell aggregation, and (3) guarantee biofilm survival. Furthermore, SE contribution to both growth and biofilm development seems to be centrally regulated by agr via quorum sensing and by saeSR and sigB. This study reveals new roles for SEs, which enforce their relevance in ensuring PC safety for transfusion patients. It further deciphers the underlying reasons for failed S. aureus detection in PCs during screening with automated culture systems.}, }
@article {pmid36676844, year = {2022}, author = {Abdulgader, M and Yu, J and Zinatizadeh, AA and Williams, P and Rahimi, Z}, title = {Effect of Different Operational Conditions on the Treatment Performance of Milk Processing Wastewater (MPW) Using a Single Stage Flexible Fibre Biofilm Reactor (SS-FFBR).}, journal = {Membranes}, volume = {13}, number = {1}, pages = {}, doi = {10.3390/membranes13010037}, pmid = {36676844}, issn = {2077-0375}, abstract = {The performance of a biofilm system, single-stage flexible fibre biofilm reactor (SS-FFBR) treating milk processing wastewater (MPW) is evaluated under various process and operational conditions. The system behavior is analyzed with different biological and physical parameters. Results show that the high COD removal efficiency of 95% is obtained at a low CODin concentration of 809 mg/L. However, the COD removal is slightly decreased to 91.7% once the CODin concentration incremented to nearly 4000 mg/L. The effect of organic loading rate (OLR) on the SS-FFBR performance is examined as total suspended solids removal efficiency, dissolved oxygen, and turbidity. The SS-FFBR showed considerable performance, so that 89.9% and 89.7% removal efficiencies in terms of COD and TSS removals, respectively, obtained at the highest OLR of 11.7 kg COD/m[3]d. TSS removal efficiency of 96.7% is obtained at a low OLR of 1.145 kg COD/m[3]d. A linear relationship between the OLR and COD removal rate was revealed. The COD removal rate was incremented from 1.08 to 10.68 kg COD/m[3]d as the OLR increased from 1.145 to 11.7 kg COD/m[3]d. Finally, the operating system is a promising technique recommended to treat various industrial wastewaters with high OLR.}, }
@article {pmid36676823, year = {2022}, author = {Alharthi, MS and Bamaga, O and Abulkhair, H and Organji, H and Shaiban, A and Macedonio, F and Criscuoli, A and Drioli, E and Wang, Z and Cui, Z and Jin, W and Albeirutty, M}, title = {Evaluation of a Hybrid Moving Bed Biofilm Membrane Bioreactor and a Direct Contact Membrane Distillation System for Purification of Industrial Wastewater.}, journal = {Membranes}, volume = {13}, number = {1}, pages = {}, doi = {10.3390/membranes13010016}, pmid = {36676823}, issn = {2077-0375}, abstract = {Integrated wastewater treatment processes are accepted as the best option for sustainable and unrestricted onsite water reuse. In this study, moving bed biofilm reactor (MBBR), membrane bioreactor (MBR), and direct contact membrane distillation (DCMD) treatment steps were integrated successively to obtain the combined advantages of these processes for industrial wastewater treatment. The MBBR step acts as the first step in the biological treatment and also mitigates foulant load on the MBR. Similarly, MBR acts as the second step in the biological treatment and serves as a pretreatment prior to the DCMD step. The latter acts as a final treatment to produce high-quality water. A laboratory scale integrated MBBR/MBR/DCMD experimental system was used for assessing the treatment efficiency of primary treated (PTIWW) and secondary treated (STIWW) industrial wastewater in terms of permeate water flux, effluent quality, and membrane fouling. The removal efficiency of total dissolved solids (TDS) and effluent permeate flux of the three-step process (MBBR/MBR/DCMD) were better than the two-step (MBR/DCMD) process. In the three-step process, the average removal efficiency of TDS was 99.85% and 98.16% when treating STIWW and PTIWW, respectively. While in the case of the two-step process, the average removal efficiency of TDS was 93.83% when treating STIWW. Similar trends were observed for effluent permeate flux values which were found, in the case of the three-step process, 62.6% higher than the two-step process, when treating STIWW in both cases. Moreover, the comparison of the quality of the effluents obtained with the analysed configurations with that obtained by Jeddah Industrial Wastewater Treatment Plant proved the higher performance of the proposed membrane processes.}, }
@article {pmid36676121, year = {2023}, author = {Mishra, S and Gupta, A and Upadhye, V and Singh, SC and Sinha, RP and Häder, DP}, title = {Therapeutic Strategies against Biofilm Infections.}, journal = {Life (Basel, Switzerland)}, volume = {13}, number = {1}, pages = {}, doi = {10.3390/life13010172}, pmid = {36676121}, issn = {2075-1729}, abstract = {A biofilm is an aggregation of surface-associated microbial cells that is confined in an extracellular polymeric substance (EPS) matrix. Infections caused by microbes that form biofilms are linked to a variety of animals, including insects and humans. Antibiotics and other antimicrobials can be used to remove or eradicate biofilms in order to treat infections. However, due to biofilm resistance to antibiotics and antimicrobials, clinical observations and experimental research clearly demonstrates that antibiotic and antimicrobial therapies alone are frequently insufficient to completely eradicate biofilm infections. Therefore, it becomes crucial and urgent for clinicians to properly treat biofilm infections with currently available antimicrobials and analyze the results. Numerous biofilm-fighting strategies have been developed as a result of advancements in nanoparticle synthesis with an emphasis on metal oxide np. This review focuses on several therapeutic strategies that are currently being used and also those that could be developed in the future. These strategies aim to address important structural and functional aspects of microbial biofilms as well as biofilms' mechanisms for drug resistance, including the EPS matrix, quorum sensing (QS), and dormant cell targeting. The NPs have demonstrated significant efficacy against bacterial biofilms in a variety of bacterial species. To overcome resistance, treatments such as nanotechnology, quorum sensing, and photodynamic therapy could be used.}, }
@article {pmid36676100, year = {2023}, author = {Lila, ASA and Rajab, AAH and Abdallah, MH and Rizvi, SMD and Moin, A and Khafagy, ES and Tabrez, S and Hegazy, WAH}, title = {Biofilm Lifestyle in Recurrent Urinary Tract Infections.}, journal = {Life (Basel, Switzerland)}, volume = {13}, number = {1}, pages = {}, doi = {10.3390/life13010148}, pmid = {36676100}, issn = {2075-1729}, abstract = {Urinary tract infections (UTIs) represent one of the most common infections that are frequently encountered in health care facilities. One of the main mechanisms used by bacteria that allows them to survive hostile environments is biofilm formation. Biofilms are closed bacterial communities that offer protection and safe hiding, allowing bacteria to evade host defenses and hide from the reach of antibiotics. Inside biofilm communities, bacteria show an increased rate of horizontal gene transfer and exchange of resistance and virulence genes. Additionally, bacterial communication within the biofilm allows them to orchestrate the expression of virulence genes, which further cements the infestation and increases the invasiveness of the infection. These facts stress the necessity of continuously updating our information and understanding of the etiology, pathogenesis, and eradication methods of this growing public health concern. This review seeks to understand the role of biofilm formation in recurrent urinary tact infections by outlining the mechanisms underlying biofilm formation in different uropathogens, in addition to shedding light on some biofilm eradication strategies.}, }
@article {pmid36675932, year = {2023}, author = {Dias, LM and Klein, MI and Ferrisse, TM and Medeiros, KS and Jordão, CC and Bellini, A and Pavarina, AC}, title = {The Effect of Sub-Lethal Successive Applications of Photodynamic Therapy on Candida albicans Biofilm Depends on the Photosensitizer.}, journal = {Journal of fungi (Basel, Switzerland)}, volume = {9}, number = {1}, pages = {}, doi = {10.3390/jof9010111}, pmid = {36675932}, issn = {2309-608X}, abstract = {This study aimed to evaluate the potential of successive applications of sub-lethal doses of the antimicrobial photodynamic therapy (aPDT) mediated by Photodithazine[®] (PDZ) and curcumin (CUR) associated with LED in the viability, reactive oxygen species (ROS) production, and gene expression of Candida albicans. The microbial assays were performed using planktonic cultures and biofilms. Ten successive applications (Apl#) were performed: aPDT (P+L+; C+L+), photosensitizer (P+L-; C+L-), and LED (P-L+; C-L+). Control groups were used (P-L-; C-L-). The viability of C. albicans was determined by cultivating treated cultures on agar plates with or without fluconazole (FLU). In addition, the ROS detection and expression of SOD1, CAP1, and ERG11 genes were determined. For planktonic cultures, no viable colonies were observed after Apl#3 (without FLU) and Apl#2 (with FLU) for either photosensitizer. Biofilm treated with P+L+ resulted in the absence of cell viability after Apl#7, while C+L+ showed ~1.40 log10 increase in cell viability after Apl#2, regardless of FLU. For both photosensitizers, after the last application with viable colonies, the production of ROS was higher in the biofilms than in the planktonic cultures, and SOD1 expression was the highest in P+L+. A reduction of CAP1 and ERG11 expression occurred after P+L+, regardless of FLU. C+L+ had a higher level of ROS, and the treatments were non-significant for gene expression. Sub-lethal doses of aPDT mediated by CUR could induce C. albicans resistance in biofilms, while C. albicans cells in biofilms were susceptible to aPDT mediated by PDZ.}, }
@article {pmid36675919, year = {2023}, author = {Kim, C and Kim, JG and Kim, KY}, title = {Anti-Candida Potential of Sclareol in Inhibiting Growth, Biofilm Formation, and Yeast-Hyphal Transition.}, journal = {Journal of fungi (Basel, Switzerland)}, volume = {9}, number = {1}, pages = {}, doi = {10.3390/jof9010098}, pmid = {36675919}, issn = {2309-608X}, abstract = {Even though Candida albicans commonly colonizes on most mucosal surfaces including the vaginal and gastrointestinal tract, it can cause candidiasis as an opportunistic infectious fungus. The emergence of resistant Candida strains and the toxicity of anti-fungal agents have encouraged the development of new classes of potential anti-fungal agents. Sclareol, a labdane-type diterpene, showed anti-Candida activity with a minimum inhibitory concentration of 50 μg/mL in 24 h based on a microdilution anti-fungal susceptibility test. Cell membrane permeability with propidium iodide staining and mitochondrial membrane potential with JC-1 staining were increased in C. albicans by treatment of sclareol. Sclareol also suppressed the hyphal formation of C. albicans in both liquid and solid media, and reduced biofilm formation. Taken together, sclareol induces an apoptosis-like cell death against Candida spp. and suppressed biofilm and hyphal formation in C. albicans. Sclareol is of high interest as a novel anti-fungal agent and anti-virulence factor.}, }
@article {pmid36675292, year = {2023}, author = {Wiessner, A and Wassmann, T and Wiessner, JM and Schubert, A and Wiechens, B and Hampe, T and Bürgers, R}, title = {In Vivo Biofilm Formation on Novel PEEK, Titanium, and Zirconia Implant Abutment Materials.}, journal = {International journal of molecular sciences}, volume = {24}, number = {2}, pages = {}, doi = {10.3390/ijms24021779}, pmid = {36675292}, issn = {1422-0067}, abstract = {The formation of biofilms on the surface of dental implants and abutment materials may lead to peri-implantitis and subsequent implant failure. Recently, innovative materials such as polyether-ether-ketone (PEEK) and its modifications have been used as abutment materials. However, there is limited knowledge on microbial adhesion to PEEK materials. The aim of this in vivo study was to investigate biofilm formation on the surface of conventional (titanium and zirconia) and PEEK implant abutment materials. Split specimens of titanium, zirconia, PEEK, and modified PEEK (PEEK-BioHPP) were manufactured, mounted in individual removable acrylic upper jaw splints, and worn by 20 healthy volunteers for 24 h. The surface roughness was determined using widefield confocal microscopy. Biofilm accumulation was investigated by fluorescence microscopy and quantified by imaging software. The surface roughness of the investigated materials was <0.2 µm and showed no significant differences between the materials. Zirconia showed the lowest biofilm formation, followed by titanium, PEEK, and PEEK-BioHPP. Differences were significant (p < 0.001) between the investigated materials, except for the polyether-ether-ketones. Generally, biofilm formation was significantly higher (p < 0.05) in the posterior region of the oral cavity than in the anterior region. The results of the present study show a material-dependent susceptibility to biofilm formation. The risk of developing peri-implantitis may be reduced by a specific choice of abutment material.}, }
@article {pmid36675120, year = {2023}, author = {Matthes, R and Jablonowski, L and Miebach, L and Pitchika, V and Holtfreter, B and Eberhard, C and Seifert, L and Gerling, T and Schlüter, R and Kocher, T and Bekeschus, S}, title = {In-Vitro Biofilm Removal Efficacy Using Water Jet in Combination with Cold Plasma Technology on Dental Titanium Implants.}, journal = {International journal of molecular sciences}, volume = {24}, number = {2}, pages = {}, doi = {10.3390/ijms24021606}, pmid = {36675120}, issn = {1422-0067}, abstract = {Peri-implantitis-associated inflammation can lead to bone loss and implant failure. Current decontamination measures are ineffective due to the implants' complex geometry and rough surfaces providing niches for microbial biofilms. A modified water jet system (WaterJet) was combined with cold plasma technology (CAP) to achieve superior antimicrobial efficacy compared to cotton gauze treatment. Seven-day-old multi-species-contaminated titanium discs and implants were investigated as model systems. The efficacy of decontamination on implants was determined by rolling the implants over agar and determining colony-forming units supported by scanning electron microscopy image quantification of implant surface features. The inflammatory consequences of mono and combination treatments were investigated with peripheral blood mononuclear cell surface marker expression and chemokine and cytokine release profiles on titanium discs. In addition, titanium discs were assayed using fluorescence microscopy. Cotton gauze was inferior to WaterJet treatment according to all types of analysis. In combination with the antimicrobial effect of CAP, decontamination was improved accordingly. Mono and CAP-combined treatment on titanium surfaces alone did not unleash inflammation. Simultaneously, chemokine and cytokine release was dramatically reduced in samples that had benefited from additional antimicrobial effects through CAP. The combined treatment with WaterJet and CAP potently removed biofilm and disinfected rough titanium implant surfaces. At the same time, non-favorable rendering of the surface structure or its pro-inflammatory potential through CAP was not observed.}, }
@article {pmid36674518, year = {2023}, author = {Diban, F and Di Lodovico, S and Di Fermo, P and D'Ercole, S and D'Arcangelo, S and Di Giulio, M and Cellini, L}, title = {Biofilms in Chronic Wound Infections: Innovative Antimicrobial Approaches Using the In Vitro Lubbock Chronic Wound Biofilm Model.}, journal = {International journal of molecular sciences}, volume = {24}, number = {2}, pages = {}, doi = {10.3390/ijms24021004}, pmid = {36674518}, issn = {1422-0067}, abstract = {Chronic wounds have harmful effects on both patients and healthcare systems. Wound chronicity is attributed to an impaired healing process due to several host and local factors that affect healing pathways. The resulting ulcers contain a wide variety of microorganisms that are mostly resistant to antimicrobials and possess the ability to form mono/poly-microbial biofilms. The search for new, effective and safe compounds to handle chronic wounds has come a long way throughout the history of medicine, which has included several studies and trials of conventional treatments. Treatments focus on fighting the microbial colonization that develops in the wound by multidrug resistant pathogens. The development of molecular medicine, especially in antibacterial agents, needs an in vitro model similar to the in vivo chronic wound environment to evaluate the efficacy of antimicrobial agents. The Lubbock chronic wound biofilm (LCWB) model is an in vitro model developed to mimic the pathogen colonization and the biofilm formation of a real chronic wound, and it is suitable to screen the antibacterial activity of innovative compounds. In this review, we focused on the characteristics of chronic wound biofilms and the contribution of the LCWB model both to the study of wound poly-microbial biofilms and as a model for novel treatment strategies.}, }
@article {pmid36674132, year = {2023}, author = {Chajęcka-Wierzchowska, W and Gajewska, J and Zakrzewski, AJ and Caggia, C and Zadernowska, A}, title = {Molecular Analysis of Pathogenicity, Adhesive Matrix Molecules (MSCRAMMs) and Biofilm Genes of Coagulase-Negative Staphylococci Isolated from Ready-to-Eat Food.}, journal = {International journal of environmental research and public health}, volume = {20}, number = {2}, pages = {}, doi = {10.3390/ijerph20021375}, pmid = {36674132}, issn = {1660-4601}, abstract = {This paper provides a snapshot on the pathogenic traits within CoNS isolated from ready-to-eat (RTE) food. Eighty-five strains were subjected to biofilm and slime production, as well as biofilm-associated genes (icaA, icaD, icaB, icaC, eno, bap, bhp, aap, fbe, embP and atlE), the insertion sequence elements IS256 and IS257 and hemolytic genes. The results showed that the most prevalent determinants responsible for the primary adherence were eno (57.6%) and aap (56.5%) genes. The icaADBC operon was detected in 45.9% of the tested strains and was correlated to slime production. Moreover, most strains carrying the icaADBC operon simultaneously carried the IS257 insertion sequence element. Among the genes encoding for surface proteins involved in the adhesion to abiotic surfaces process, atlE was the most commonly (31.8%) followed by bap (4.7%) and bhp (1.2%). The MSCRAMMs, including fbe and embp were detected in the 11.8% and 28.2% of strains, respectively. A high occurrence of genes involved in the hemolytic toxin production were detected, such as hla_yiD (50.6%), hlb (48.2%), hld (41.2%) and hla_haem (34.1%). The results of the present study revealed an unexpected occurrence of the genes involved in biofilm production and the high hemolytic activity among the CoNS strains, isolated from RTE food, highlighting that this group seems to be acquiring pathogenic traits similar to those of S. aureus, suggesting the need to be included in the routine microbiological analyses of food.}, }
@article {pmid36672846, year = {2022}, author = {Asante, J and Abia, ALK and Anokwah, D and Hetsa, BA and Fatoba, DO and Bester, LA and Amoako, DG}, title = {Phenotypic and Genomic Insights into Biofilm Formation in Antibiotic-Resistant Clinical Coagulase-Negative Staphylococcus Species from South Africa.}, journal = {Genes}, volume = {14}, number = {1}, pages = {}, doi = {10.3390/genes14010104}, pmid = {36672846}, issn = {2073-4425}, abstract = {The work aims to investigate biofilm formation and biofilm/adhesion-encoding genes in coagulase-negative staphylococci (CoNS) species recovered from blood culture isolates. Eighty-nine clinical CoNS were confirmed using the VITEK 2 system, and antibiotic susceptibility testing of isolates was conducted using the Kirby-Bauer disk diffusion method against a panel of 20 antibiotics. Isolates were qualitatively screened using the Congo red agar medium. Quantitative assays were performed on microtiter plates, where the absorbances of the solubilised biofilms were recorded as optical densities and quantified. In all, 12.4% of the isolates were strong biofilm formers, 68.5% had moderate biofilm capacity, and 17.9% showed weak capacity. A subset of 18 isolates, mainly methicillin-resistant S. epidermidis, were investigated for adherence-related genes using whole-genome sequencing and bioinformatics analysis. The highest antibiotic resistance rates for strongly adherent isolates were observed against penicillin (100%) and cefoxitin (81.8%), but the isolates showed no resistance to linezolid (0.0%) and tigecycline (0.0%). The icaABC genes involved in biofilm formation were detected in 50% of the screened isolates. Other adherence-related genes, including autolysin gene atl (88.8%), elastin binding protein gene ebp (94.4%), cell wall-associated fibronectin-binding protein gene ebh (66.7%), clumping factor A gene clfA (5.5%), and pili gene ebpC (22.2%) were also found. The insertion sequence IS256, involved in biofilm formation, was found in 10/18 (55.5%) screened isolates. We demonstrate a high prevalence of biofilm-forming coagulase-negative staphylococci associated with various resistance phenotypes and a substantial agreement between the possession of biofilm-associated genes and the biofilm phenotype.}, }
@article {pmid36671356, year = {2023}, author = {Laconi, A and Tolosi, R and Apostolakos, I and Piccirillo, A}, title = {Biofilm Formation Ability of ESBL/pAmpC-Producing Escherichia coli Isolated from the Broiler Production Pyramid.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {1}, pages = {}, doi = {10.3390/antibiotics12010155}, pmid = {36671356}, issn = {2079-6382}, abstract = {Escherichia coli able to produce extended spectrum β-lactamases (ESBLs) and plasmid-mediated AmpC β-lactamases (pAmpCs) represents a serious threat to public health, since these genes confer resistance to critically important antimicrobials (i.e., third generation cephalosporins) and can be transferred to non-resistant bacteria via plasmids. E. coli are known to be able to form a biofilm, which represents a favorable environment for the exchange of resistance determinants. Here, we assessed the ability of 102 ESBL/pAmpC-producing E. coli isolated from the broiler production pyramid to form a biofilm and to identify genetic factors involved in biofilm formation. All but one of the ESBL/pAmpC-producing E. coli were able to form a biofilm, and this represents a great concern to public health. E. coli belonging to phylogroups D, E, and F, as well as strains harboring the blaCTX-M-type gene, seem to be associated with an increased biofilm capability (p < 0.05). Furthermore, virulence genes involved in adherence and invasion (i.e., csgBAC, csgDEFG, matABCDEF, and sfaX) seem to enhance biofilm formation in E. coli. Efforts should be made to reduce the presence of ESBL/pAmpC- and biofilm-producing E. coli in the broiler production pyramid and, therefore, the risk of dissemination of resistant bacteria and genes.}, }
@article {pmid36671344, year = {2023}, author = {Puvača, N and Ljubojević Pelić, D and Pelić, M and Bursić, V and Tufarelli, V and Piemontese, L and Vuković, G}, title = {Microbial Resistance to Antibiotics and Biofilm Formation of Bacterial Isolates from Different Carp Species and Risk Assessment for Public Health.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {1}, pages = {}, doi = {10.3390/antibiotics12010143}, pmid = {36671344}, issn = {2079-6382}, abstract = {The aim of this research was to investigate the effects of biofilm on antibiotic resistance of the bacterial isolates present in fish meat and to assess the risk of antibiotic residues for public health. Common carp, silver carp and grass carp fishes were purchased from retail stores for an in vitro biofilm investigation and a drug-resistant pattern determination. In all samples, up to 10[4] CFU/g of bacteria, such as Escherichia coli, Aeromonas hydrophila, Shewanella putrefaciens, Vibrio spp. and Staphylococcus spp., were observed. Isolates from the samples and their biofilms were subjected to an antibiogram assay using antibiotics such as amoxicillin, ampicillin, cefotaxime, ciprofloxacin, chloramphenicol, gentamicin, streptomycin, tetracycline and trimethoprim. Obtained results showed that some of the isolates were sensitive to antibiotics and some were resistant. Results of LC-MS/MS analysis showed that antibiotics residues were present in fish samples in the range between 4.9 and 199.4 µg/kg, with a total sum of 417.1 µg/kg. Estimated daily intake (EDI) was established to be 0.274 μg/kg of body weight/day for men and 0.332 μg/kg of body weight/day for women, with an acceptable daily intake (ADI) of 8.5 and 7.0 µg/kg of body weight/day for men and women, respectively. The results of the present study, therefore, highlight the safe consumption of fresh fish.}, }
@article {pmid36671333, year = {2023}, author = {Dong, CL and Che, RX and Wu, T and Qu, QW and Chen, M and Zheng, SD and Cai, XH and Wang, G and Li, YH}, title = {New Characterization of Multi-Drug Resistance of Streptococcus suis and Biofilm Formation from Swine in Heilongjiang Province of China.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {1}, pages = {}, doi = {10.3390/antibiotics12010132}, pmid = {36671333}, issn = {2079-6382}, abstract = {The aim of this study was to investigate the antimicrobial resistance profiles and genotypes of Streptococcus suis in Heilongjiang Province, China. A total of 29 S. suis were isolated from 332 samples collected from 6 pig farms. The results showed that serotypes 2, 4 and 9 were prevalent, and all the clinical isolates were resistant to at least two antibacterial drugs. The most resisted drugs were macrolides, and the least resisted drugs were fluoroquinolones. Resistant genes ermB and aph (3')-IIIa were highly distributed among the isolates, with the detection rates of 79.31% and 75.86%. The formation of biofilm could be observed in all the isolated S. suis, among which D-1, LL-1 and LL-3 strains formed stronger biofilm structure than other strains. The results indicate that S. suis in Heilongjiang Province presents a multi-drug resistance to commonly used antimicrobial drugs, which was caused by the same target gene, the dissemination of drug resistance genes, and bacterial biofilm.}, }
@article {pmid36671319, year = {2023}, author = {Prinz, J and Wink, M and Neuhaus, S and Grob, MC and Walt, H and Bosshard, PP and Achermann, Y}, title = {Effective Biofilm Eradication on Orthopedic Implants with Methylene Blue Based Antimicrobial Photodynamic Therapy In Vitro.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {1}, pages = {}, doi = {10.3390/antibiotics12010118}, pmid = {36671319}, issn = {2079-6382}, abstract = {Periprosthetic joint infections (PJI) are difficult to treat due to biofilm formation on implant surfaces, often requiring removal or exchange of prostheses along with long-lasting antibiotic treatment. This in vitro study investigated the effect of methylene blue photodynamic therapy (MB-PDT) on PJI-causing biofilms on different implant materials. MB-PDT (664 nm LED, 15 J/cm[2]) was tested on different Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Cutibacterium acnes strains in both planktonic form and grown in early and mature biofilms on prosthetic materials (polyethylene, titanium alloys, cobalt-chrome-based alloys, and bone cement). The minimum bactericidal concentration with 100% killing (MBC100%) was determined. Chemical and topographical alterations were investigated on the prosthesis surfaces after MB-PDT. Results showed a MBC100% of 0.5-5 μg/mL for planktonic bacteria and 50-100 μg/mL for bacteria in biofilms-independent of the tested strain, the orthopedic material, or the maturity of the biofilm. Material testing showed no relevant surface modification. MB-PDT effectively eradicated common PJI pathogens on arthroplasty materials without damage to the materials, suggesting that MB-PDT could be used as a novel treatment method, replacing current, more invasive approaches and potentially shortening the antibiotic treatment in PJI. This would improve quality of life and reduce morbidity, mortality, and high health-care costs.}, }
@article {pmid36671311, year = {2023}, author = {Kaur, H and Chaudhary, N and Modgil, V and Kalia, M and Kant, V and Mohan, B and Bhatia, A and Taneja, N}, title = {In Vitro and In Vivo Studies of Heraclenol as a Novel Bacterial Histidine Biosynthesis Inhibitor against Invasive and Biofilm-Forming Uropathogenic Escherichia coli.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {1}, pages = {}, doi = {10.3390/antibiotics12010110}, pmid = {36671311}, issn = {2079-6382}, abstract = {Globally, urinary tract infections (UTIs) are one of the most frequent bacterial infections. Uropathogenic Escherichia coli (UPEC) are the predominant etiological agents causing community and healthcare-associated UTIs. Biofilm formation is an important pathogenetic mechanism of UPEC responsible for chronic and recurrent infections. The development of high levels of antimicrobial resistance (AMR) among UPEC has complicated therapeutic management. Newer antimicrobial agents are needed to tackle the increasing trend of AMR and inhibit biofilms. Heraclenol is a natural furocoumarin compound that inhibits histidine biosynthesis selectively. In this study, for the first time, we have demonstrated the antimicrobial and antibiofilm activity of heraclenol against UPEC. The drug reduced the bacterial load in the murine catheter UTI model by ≥4 logs. The drug effectively reduced bacterial loads in kidney, bladder, and urine samples. On histopathological examination, heraclenol treatment showed a reversal of inflammatory changes in the bladder and kidney tissues. It reduced the biofilm formation by 70%. The MIC value of heraclenol was observed to be high (1024 µg/mL), though the drug at MIC concentration did not have significant cytotoxicity on the Vero cell line. Further molecular docking revealed that heraclenol binds to the active site of the HisC, thereby preventing its activation by native substrate, which might be responsible for its antibacterial and antibiofilm activity. Since the high MIC of heraclenol is not achievable clinically in human tissues, further chemical modifications will be required to lower the drug's MIC value and increase its potency. Alternatively, its synergistic action with other antimicrobials may also be studied.}, }
@article {pmid36671272, year = {2022}, author = {Barros, ILE and Veiga, FF and de Castro-Hoshino, LV and Souza, M and Malacrida, AM and Diniz, BV and Dos Santos, RS and Bruschi, ML and Baesso, ML and Negri, M and Svidzinski, TIE}, title = {Performance of Two Extracts Derived from Propolis on Mature Biofilm Produced by Candida albicans.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {1}, pages = {}, doi = {10.3390/antibiotics12010072}, pmid = {36671272}, issn = {2079-6382}, abstract = {Species of the Candida genus represent the third most common cause of onychomycosis, the most frequent and difficult to treat nail infection. Onychomycosis has been attributed to fungi organized in biofilm and some natural products have proved promising for its treatment. This study aimed to evaluate the antibiofilm activity of propolis extract (PE) and its by-product (WPE) on 7-day preformed biofilms produced by Candida albicans in polystyrene microplates, as well as in an ex vivo model on human nail fragments. The cytotoxicity and permeation capacity were also assessed. Firstly, multiple parameters were evaluated over 7 days to elucidate the dynamics of biofilm formation by C. albicans. The cell viability and total biomass did not vary much from the beginning; however, days 3 and 4 were crucial in terms of metabolic activity, which was significantly increased, and the levels of extracellular matrix components, wherein proteins and nucleic acids experienced an increase, but polysaccharide levels dropped. Architecturally, one-day biofilm showed a monolayer of organized cells (blastoconidia, hyphae, and pseudohyphae), while in the seven-day biofilm there was a three-dimensional well-structured and complex biofilm. This yeast was also able to form a biofilm on both surfaces of the nail, without an additional nutritional source. Both extracts showed excellent antibiofilm activity against the 7-day preformed biofilm and were not toxic to Vero cells at concentrations compatible with the antifungal and antibiofilm activities. Both extracts permeated the experimentally infected nail, with WPE being more efficient. The results of this study, taken together, reinforce the potential of these natural products, containing propolis, as a safe option for the topical treatment of onychomycosis.}, }
@article {pmid36671269, year = {2022}, author = {Sparbrod, M and Gager, Y and Koehler, AK and Jentsch, H and Stingu, CS}, title = {Relationship between Phenotypic and Genotypic Resistance of Subgingival Biofilm Samples in Patients with Periodontitis.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {1}, pages = {}, doi = {10.3390/antibiotics12010068}, pmid = {36671269}, issn = {2079-6382}, abstract = {The phenotypic expression of antibiotic resistance genes (ARGs) can hamper the use of antibiotics as adjuncts to subgingival instrumentation in the treatment of periodontitis patients. The aim of the study was to analyze the relationship between the phenotypic and genotypic resistance against ampicillin-sulbactam, clindamycin, doxycycline and metronidazole of subgingival biofilm samples from 19 periodontitis patients. Samples were analyzed with shotgun sequencing and cultivated anaerobically for 7 days on microbiological culture media incorporating antibiotics. All growing isolates were identified to the species level using MALDI-TOF-MS and sequence analysis of the 16S ribosomal RNA (rRNA) gene. Phenotypic resistance was determined using EUCAST-breakpoints. The genetic profile of eight patients matched completely with phenotypical resistance to the tested antibiotics. The positive predictive values varied from 1.00 for clindamycin to 0.57 for doxycycline and 0.25 for ampicillin-sulbactam. No sample contained the nimI gene. It can be concluded that antibiotic resistance may be polygenetic and genes may be silent. Every biofilm sample harboring erm genes was phenotypic resistant. The absence of cfx and tet genes correlated to 100%, respectively, to 75%, with the absence of phenotypic resistance. The absence of nimI genes leads to the assumption that constitutive resistance among several species could explain the resistance to metronidazole.}, }
@article {pmid36671255, year = {2022}, author = {Ciarolla, AA and Lapin, N and Williams, D and Chopra, R and Greenberg, DE}, title = {Physical Approaches to Prevent and Treat Bacterial Biofilm.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {1}, pages = {}, doi = {10.3390/antibiotics12010054}, pmid = {36671255}, issn = {2079-6382}, abstract = {Prosthetic joint infection (PJI) presents several clinical challenges. This is in large part due to the formation of biofilm which can make infection eradication exceedingly difficult. Following an extensive literature search, this review surveys a variety of non-pharmacological methods of preventing and/or treating biofilm within the body and how they could be utilized in the treatment of PJI. Special attention has been paid to physical strategies such as heat, light, sound, and electromagnetic energy, and their uses in biofilm treatment. Though these methods are still under study, they offer a potential means to reduce the morbidity and financial burden related to multiple stage revisions and prolonged systemic antibiotic courses that make up the current gold standard in PJI treatment. Given that these options are still in the early stages of development and offer their own strengths and weaknesses, this review offers an assessment of each method, the progress made on each, and allows for comparison of methods with discussion of future challenges to their implementation in a clinical setting.}, }
@article {pmid36671212, year = {2022}, author = {Peng, Q and Tang, X and Dong, W and Sun, N and Yuan, W}, title = {A Review of Biofilm Formation of Staphylococcus aureus and Its Regulation Mechanism.}, journal = {Antibiotics (Basel, Switzerland)}, volume = {12}, number = {1}, pages = {}, doi = {10.3390/antibiotics12010012}, pmid = {36671212}, issn = {2079-6382}, abstract = {Bacteria can form biofilms in natural and clinical environments on both biotic and abiotic surfaces. The bacterial aggregates embedded in biofilms are formed by their own produced extracellular matrix. Staphylococcus aureus (S. aureus) is one of the most common pathogens of biofilm infections. The formation of biofilm can protect bacteria from being attacked by the host immune system and antibiotics and thus bacteria can be persistent against external challenges. Therefore, clinical treatments for biofilm infections are currently encountering difficulty. To address this critical challenge, a new and effective treatment method needs to be developed. A comprehensive understanding of bacterial biofilm formation and regulation mechanisms may provide meaningful insights against antibiotic resistance due to bacterial biofilms. In this review, we discuss an overview of S. aureus biofilms including the formation process, structural and functional properties of biofilm matrix, and the mechanism regulating biofilm formation.}, }
@article {pmid36670360, year = {2023}, author = {Zang, YM and Liu, JF and Li, G and Zhao, M and Yin, GM and Zhang, ZP and Jia, W}, title = {The first case of Escherichia fergusonii with biofilm in China and literature review.}, journal = {BMC infectious diseases}, volume = {23}, number = {1}, pages = {35}, pmid = {36670360}, issn = {1471-2334}, abstract = {BACKGROUND: Escherichia fergusonii is a rare opportunistic pathogen in humans and animals, especially with biofilm.<br><br>METHODS: In one case, E. fergusonii with biofilm was detected in the bile, and silver staining was used to prove it had biofilm. The clinical characteristics and drug susceptibility of eight cases of E. fergusonii retrieved from the literature were also summarized.<br><br>RESULTS: This is a case of E. fergusonii with biofilm, which has not been reported in China. The 8 cases retrieved from the literature did not specify whether they had biofilm, but we analyzed their clinical characteristics and drug susceptibility. All patients were treated with antimicrobial drugs. 8 cases showed sensitivity to piperacillin/tazobactam and imipenem in 6 cases (75%), but poor sensitivity to levofloxacin and ciprofloxacin.<br><br>CONCLUSION: The silver staining method proved biofilm in this case, which is the first case of E. fergusonii with biofilm in China.}, }
@article {pmid36670157, year = {2023}, author = {da Silva Barreira, D and Laurent, J and Lourenço, J and Novion Ducassou, J and Couté, Y and Guzzo, J and Rieu, A}, title = {Membrane vesicles released by Lacticaseibacillus casei BL23 inhibit the biofilm formation of Salmonella Enteritidis.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {1163}, pmid = {36670157}, issn = {2045-2322}, abstract = {Biofilms represent a major concern in the food industry and healthcare. The use of probiotic bacteria and their derivatives as an alternative to conventional treatments to fight biofilm development is a promising option that has provided convincing results in the last decades. Recently, membrane vesicles (MVs) produced by probiotics have generated considerable interest due to the diversity of roles they have been associated with. However, the antimicrobial activity of probiotic MVs remains to be studied. In this work, we showed that membrane vesicles produced by Lacticaseibacillus casei BL23 (LC-MVs) exhibited strong antibiofilm activity against Salmonella enterica serovar Enteritidis (S. Enteritidis) without affecting bacterial growth. Furthermore, we found that LC-MVs affected the early stages of S. Enteritidis biofilm development and prevented attachment of bacteria to polystyrene surfaces. Importantly, LC-MVs did not impact the biomass of already established biofilms. We also demonstrated that the antibiofilm activity depended on the proteins associated with the LC-MV fraction. Finally, two peptidoglycan hydrolases (PGHs) were found to be associated with the antibiofilm activity of LC-MVs. Overall, this work allowed to identify the antibiofilm properties of LC-MVs and paved the way for the use of probiotic MVs against the development of negative biofilms.}, }
@article {pmid36669724, year = {2023}, author = {Gonçalves, B and Barbosa, A and Soares, AR and Henriques, M and Silva, S}, title = {Sfl1 is required for Candida albicans biofilm formation under acidic conditions.}, journal = {Biochimie}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.biochi.2023.01.011}, pmid = {36669724}, issn = {1638-6183}, abstract = {Candida albicans is a common Candida species, responsible for infections in various anatomical sites under different environmental conditions, aggravated in the presence of its biofilms. As such, this study aimed to reveal the regulation of C. albicans biofilms under acidic conditions by the transcription factor Sfl1, whose role on biofilm formation is unclear. For that, microbiologic and transcriptomic analyses were performed with the knock-out mutant C. albicans sfl1Δ/sfl1Δ and its parental strain SN76, grown in planktonic and biofilm lifestyles at pH 4 (vaginal pH). The results revealed that despite being a filamentation repressor Sf1 is required for maximal biofilm formation under acidic conditions. Additionally, Sfl1 was found to induce 275 and 126 genes in biofilm and planktonic cells, respectively, with an overlap of 19 genes. The functional distribution of Sfl1 targets was similar in planktonic and biofilm modes but an enrichment of carbohydrate metabolism function was found in biofilm cells, including some genes encoding proteins involved in the biofilm matrix production. Furthermore, this study shows that the regulatory network of Sfl1 in acidic biofilms is complex and include the positive and negative regulation of transcription factors involved in adhesion and biofilm formation, such as AHR1, BRG1, TYE7, TEC1, WOR1, and various of their targets. Overall, this study shows that Sfl1 is a relevant regulator of C. albicans biofilm formation in acidic environments and contributes to a better understanding of C. albicans virulence under acidic conditions.}, }
@article {pmid36669662, year = {2023}, author = {Villa, F and Ludwig, N and Mazzini, S and Scaglioni, L and Fuchs, AL and Tripet, B and Copié, V and Stewart, PS and Cappitelli, F}, title = {A desiccated dual-species subaerial biofilm reprograms its metabolism and affects water dynamics in limestone.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {161666}, doi = {10.1016/j.scitotenv.2023.161666}, pmid = {36669662}, issn = {1879-1026}, abstract = {Understanding the impact of sessile communities on underlying materials is of paramount importance in stone conservation. Up until now, the critical role of subaerial biofilms (SABs) whether they are protective or deteriorative remains unclear, especially under desiccation. The interest in desiccated SABs is raised by the prediction of an increase in drought events in the next decades that will affect the Mediterranean regions' rich stone heritage as never before. Thus, the main goal of this research is to study the effects of desiccation on both the biofilms' eco-physiology and its impacts on the lithic substrate. To this end, we used a dual-species model system composed of a phototroph and a chemotroph to simulate biofilm behavior on stone heritage. We found that drought altered the phototroph-chemotroph balance and enriched the biofilm matrix with proteins and DNA. Desiccated SABs underwent a shift in metabolism to fermentation and a decrease in oxidative stress. Additionally, desiccated SABs changed the water-related dynamics (adsorption, evaporation, and wetting properties) in limestone. Water absorption experiments showed that desiccated SABs protected the stone from rapid water uptake, while a thermographic survey indicated a delay in water evaporation. Spilling-drop tests revealed a change in the wettability of the stone-SAB interface, which affected the water transport properties of the stone. Finally, desiccated SABs reduced stone swelling in the presence of water vapor. The biodeteriorative and bioprotective implications of desiccated SABs on the stone were ultimately assessed.}, }
@article {pmid36669302, year = {2023}, author = {Si, Z and Li, J and Ruan, L and Reghu, S and Ooi, YJ and Li, P and Zhu, Y and Hammond, PT and Verma, CS and Bazan, GC and Pethe, K and Chan-Park, MB}, title = {Designer co-beta-peptide copolymer selectively targets resistant and biofilm Gram-negative bacteria.}, journal = {Biomaterials}, volume = {294}, number = {}, pages = {122004}, doi = {10.1016/j.biomaterials.2023.122004}, pmid = {36669302}, issn = {1878-5905}, abstract = {New antimicrobials are urgently needed to combat Gram-negative bacteria, particularly multi-drug resistant (MDR) and phenotypically resistant biofilm species. At present, only sequence-defined alpha-peptides (e.g. polymyxin B) can selectively target Gram-negative bacterial lipopolysaccharides. We show that a copolymer, without a defined sequence, shows good potency against MDR Gram-negative bacteria including its biofilm form. The tapered blocky co-beta-peptide with controlled N-terminal hydrophobicity (#4) has strong interaction with the Gram-negative bacterial lipopolysaccharides via its backbone through electrostatic and hydrogen bonding interactions but not the Gram-positive bacterial and mammalian cell membranes so that this copolymer is non-toxic to these two latter cell types. The new #4 co-beta-peptide selectively kills Gram-negative bacteria with low cytotoxicity both in vitro and in a mouse biofilm wound infection model. This strategy provides a new concept for the design of Gram-negative selective antimicrobial peptidomimetics against MDR and biofilm species.}, }
@article {pmid36669095, year = {2023}, author = {Lorenz, K and Preem, L and Sagor, K and Putrinš, M and Tenson, T and Kogermann, K}, title = {Development of In Vitro and Ex Vivo Biofilm Models for the Assessment of Antibacterial Fibrous Electrospun Wound Dressings.}, journal = {Molecular pharmaceutics}, volume = {}, number = {}, pages = {}, doi = {10.1021/acs.molpharmaceut.2c00902}, pmid = {36669095}, issn = {1543-8392}, abstract = {Increasing evidence suggests that the chronicity of wounds is associated with the presence of bacterial biofilms. Therefore, novel wound care products are being developed, which can inhibit biofilm formation and/or treat already formed biofilms. A lack of standardized assays for the analysis of such novel antibacterial drug delivery systems enhances the need for appropriate tools and models for their characterization. Herein, we demonstrate that optimized and biorelevant in vitro and ex vivo wound infection and biofilm models offer a convenient approach for the testing of novel antibacterial wound dressings for their antibacterial and antibiofilm properties, allowing one to obtain qualitative and quantitative results. The in vitro model was developed using an electrospun (ES) thermally crosslinked gelatin-glucose (GEL-Glu) matrix and an ex vivo wound infection model using pig ear skin. Wound pathogens were used for colonization and biofilm development on the GEL-Glu matrix or pig skin with superficial burn wounds. The in vitro model allowed us to obtain more reproducible results compared with the ex vivo model, whereas the ex vivo model had the advantage that several pathogens preferred to form a biofilm on pig skin compared with the GEL-Glu matrix. The in vitro model functioned poorly for Staphylococcus epidermidis biofilm formation, but it worked well for Escherichia coli and Staphylococcus aureus, which were able to use the GEL-Glu matrix as a nutrient source and not only as a surface for biofilm growth. On the other hand, all tested pathogens were equally able to produce a biofilm on the surface of pig skin. The developed biofilm models enabled us to compare different ES dressings [pristine and chloramphenicol-loaded polycaprolactone (PCL) and PCL-poly(ethylene oxide) (PEO) (PCL/PEO) dressings] and understand their biofilm inhibition and treatment properties on various pathogens. Furthermore, we show that biofilms were formed on the wound surface as well as on a wound dressing, indicating that the demonstrated methods mimic well the in vivo situation. Colony forming unit (CFU) counting and live biofilm matrix as well as bacterial DNA staining together with microscopic imaging were performed for biofilm quantification and visualization, respectively. The results showed that both wound biofilm models (in vitro and ex vivo) enabled the evaluation of the desired antibiofilm properties, thus facilitating the design and development of more effective wound care products and screening of various formulations and active substances.}, }
@article {pmid36661559, year = {2023}, author = {Cobb, CM and Harrel, SK and Zhao, D and Spencer, P}, title = {Effect of EDTA Gel on Residual Subgingival Calculus and Biofilm: An In Vitro Pilot Study.}, journal = {Dentistry journal}, volume = {11}, number = {1}, pages = {}, doi = {10.3390/dj11010022}, pmid = {36661559}, issn = {2304-6767}, abstract = {BACKGROUND: Residual calculus, following scaling and root planing (SRP), is associated with persistent inflammation and the progression of periodontitis. This study examined the effects of a 24% neutral ethylenediaminetetraacetic acid (EDTA) gel on subgingival calculus and biofilms.<br><br>METHODS: Eleven single-rooted teeth extracted because of severe periodontal disease were randomly assigned to the following treatment groups: (1) three teeth served as untreated controls; (2) three teeth were treated by scaling and root planing (SRP) only; and (3) three teeth were treated by SRP + EDTA. The remaining two teeth, one SRP only and the other SRP + EDTA were designated for energy-dispersive X-ray spectroscopy (EDS) analysis. EDTA gel was placed on the SRP surface for 2 min and then burnished with a sterile cotton pellet.<br><br>RESULTS: SRP + EDTA treated specimens exhibited severely damaged biofilm and the disruption of the extracellular polymeric matrix. EDS scans of the smear layer and calculus featured reductions in the Weight % and Atomic % for N, F, Na, and S and increases in Mg, P, and Ca.<br><br>CONCLUSIONS: A 25% neutral EDTA gel was applied after SRP severely disrupted the residual biofilm and altered the character of dental calculus and the smear layer as shown by reductions in the Weight % and Atomic % for N, F, Na, and S and increases in Mg, P, and Ca.}, }
@article {pmid36661550, year = {2023}, author = {Baybekov, O and Stanishevskiy, Y and Sachivkina, N and Bobunova, A and Zhabo, N and Avdonina, M}, title = {Isolation of Clinical Microbial Isolates during Orthodontic Aligner Therapy and Their Ability to Form Biofilm.}, journal = {Dentistry journal}, volume = {11}, number = {1}, pages = {}, doi = {10.3390/dj11010013}, pmid = {36661550}, issn = {2304-6767}, abstract = {The purpose of this study is to calculate microbiological composition of aligners after a day of wearing them. To date, the dental market for orthodontists offers many ways to correct bites. Aligners are transparent and almost invisible from the teeth. They are used for everyday wear to correct the incorrect position of the teeth, which was once considered the prerogative of braces. Scientists worldwide have repeatedly considered questions regarding the interaction between aligners and the oral cavity's microflora; however, the emphasis has mainly shifted toward species composition and antibiotic resistance. The various properties of these microorganisms, including biofilm formation, adhesion to various cells, and the ability to phagocytize, have not been studied so widely. In addition, these characteristics, as well as the microorganisms themselves, have properties that change over time, location, and in certain conditions. In this regard, the problem of biofilm formation in dental practice is always relevant. It requires constant monitoring since high contamination of orthodontic materials can reduce the effectiveness of local anti-inflammatory therapy and cause relapses in caries and inflammatory diseases of the oral cavity. Adhesive properties, one of the key factors in forming the architectonics of biofilms, provide the virulence factors of microorganisms and are characterized by an increase in optical density, determining the duration and retrospectivity of diagnostic studies. This paper focuses on the isolation of clinical microbial isolates during aligner therapy and their ability to form biofilms. In the future, we plan to use the obtained strains of microorganisms to create an effective and safe biofilm-destroying agent. We aimed to study morphometric and densitometric indicators of biofilms of microorganisms persisting on aligners.}, }
@article {pmid36660946, year = {2023}, author = {Liu, X and Xu, S and Chen, X and Kang, S and Liu, J and Jiang, Q and Zhang, S and Hao, L and Ran, H and Huang, W and Zhang, D}, title = {Synergistic effect of bovine cateslytin-loaded nanoparticles combined with ultrasound against Candida albicans biofilm.}, journal = {Future medicinal chemistry}, volume = {}, number = {}, pages = {}, doi = {10.4155/fmc-2022-0062}, pmid = {36660946}, issn = {1756-8927}, abstract = {Purpose: To investigate the synergistic effect of bovine cateslytin-loaded nanoparticles (bCAT-NPs) combined with ultrasound against Candida albicans biofilm and uncover the underlying mechanism. Methods: bCAT-NPs were prepared by the double emulsion method, and toxicity was observed by the hemolysis ratio. The metabolic activity and viable cell biomass, morphology and membrane permeability of C. albicans biofilm were observed. The expression of ALS3 mRNA, the content of reactive oxygen species, was detected. Finally, bCAT structure was analyzed. Results &amp; conclusion: The hemolysis ratio of the bCAT-NPs group was significantly lower than that of the bCAT group. bCAT-NPs combined with ultrasound significantly reduced biofilm metabolic activity, inhibited the formation of hyphae, decreased the expression of ALS3 mRNA and increased the intracellular reactive oxygen species content. In the in vivo experiments, the colony-forming units/ml in the ultrasound+bCAT-NPs group decreased, and a few planktonic fungal cells were observed.}, }
@article {pmid36660364, year = {2023}, author = {Laulund, AS and Schwartz, FA and Christophersen, L and Kolpen, M and Østrup Jensen, P and Calum, H and Høiby, N and Thomsen, K and Moser, C}, title = {Hyperbaric oxygen therapy augments ciprofloxacin effect against Pseudomonas aeruginosa biofilm infected chronic wounds in a mouse model.}, journal = {Biofilm}, volume = {5}, number = {}, pages = {100100}, pmid = {36660364}, issn = {2590-2075}, abstract = {INTRODUCTION: Chronic wounds have a compromised microcirculation which leads to restricted gas exchange. The majority of these hypoxic wounds is infested with microorganisms congregating in biofilms which further hinders the antibiotic function. We speculate whether this process can be counteracted by hyperbaric oxygen therapy (HBOT).<br><br>METHODOLOGY: Twenty-eight BALB/c mice with third-degree burns were included in the analyses. Pseudomonas aeruginosa embedded in seaweed alginate beads was injected under the eschar to mimic a biofilm infected wound. Challenged mice were randomized to receive either 4 days with 1 x ciprofloxacin combined with 2&#xa0;&#xd7;&#xa0;90&#xa0;min HBOT at 2.8 standard atmosphere daily, 1 x ciprofloxacin as monotherapy or saline as placebo. The mice were clinically scored, and wound sizes were estimated by planimetry daily. Euthanasia was performed on day 8. Wounds were surgically removed in toto, homogenized and plated for quantitative bacteriology. Homogenate supernatants were used for cytokine analysis.<br><br>RESULTS: P. aeruginosa was present in all wounds at euthanasia. A significant lower bacterial load was seen in the HBOT group compared to either the monotherapy ciprofloxacin group (p&#xa0;=&#xa0;0.0008), or the placebo group (p&#xa0;<&#xa0;0.0001). IL-1&#x3b2; level was significantly lower in the HBOT group compared to the placebo group (p&#xa0;=&#xa0;0.0007). Both treatment groups had higher osteopontin levels than the placebo group (p&#xa0;=&#xa0;0.002 and p&#xa0;=&#xa0;0.004). The same pattern was seen in the S100A9 analysis (p&#xa0;=&#xa0;0.01 and p&#xa0;=&#xa0;0.008), whereas no differences were detected between the S100A8, the VEGF or the MMP8 levels in the three groups.<br><br>CONCLUSION: These findings show that HBOT improves the bactericidal activity of ciprofloxacin against P. aeruginosa wound biofilm in vivo. HBOT in addition to ciprofloxacin also modulates the host response to a less inflammatory phenotype.}, }
@article {pmid36658772, year = {2023}, author = {Mousavi, SM and Mousavi, SMA and Moeinizadeh, M and Aghajanidelavar, M and Rajabi, S and Mirshekar, M}, title = {Evaluation of biosynthesized silver nanoparticles effects on expression levels of virulence and biofilm-related genes of multidrug-resistant Klebsiella pneumoniae isolates.}, journal = {Journal of basic microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1002/jobm.202200612}, pmid = {36658772}, issn = {1521-4028}, abstract = {The emergence of multidrug-resistant (MDR) strains of Klebsiella pneumoniae is associated with high morbidity and mortality due to limited treatment options. This study attempts to biologically synthesize silver nanoparticles (AgNPs) and investigate their effect on expression levels of virulence and biofilm-related genes in clinically isolated K. pneumoniae. In this study, biofilm formation ability, antibiotic resistance pattern, extended-spectrum β-lactamases (ESBLs), and carbapenemases production were investigated for 200 clinical isolates of K. pneumoniae using phenotypic methods. Polymerase chain reaction (PCR) was used to detect virulence and biofilm-related genes, ESBL-encoding genes, and carbapenem resistance genes. AgNPs were synthesized using the bio-reduction method. The antibacterial effects of AgNPs were investigated by microdilution broth. In addition, the cytotoxic effect of AgNPs on L929 fibroblast cell lines was determined. The effects of AgNPs on K. pneumoniae virulence and biofilm-related genes (fimH, rmpA, and mrkA) were determined using quantitative real-time PCR. Thirty percent of the isolates produced a strong biofilm. The highest and lowest levels of resistance were observed against amoxicillin/clavulanic acid (95.4%) and tigecycline (96%), respectively. About 31% of isolates were considered positive for carbapenemases, and 75% of the isolates produced an ESBLs enzyme. Different frequencies of mentioned genes were observed. The synthesized AgNPs had a spherical morphology and varied in size. AgNPs inhibited the growth of MDR K. pneumoniae at 128 µg/ml. In addition, AgNPs downregulated the expression of fimH, rmpA, and mrkA genes by 10, 7, and 14-fold, respectively (p < 0.05), also exerted no cytotoxic effect on L929 fibroblast cell lines. It was revealed that AgNPs lead to a decrease in expression levels of virulence and biofilm-related genes; therefore, it was concluded that AgNPs had an excellent antibacterial effect on MDR K. pneumoniae.}, }
@article {pmid36658553, year = {2023}, author = {Wang, J and Geng, T and Wang, Y and Yuan, C and Wang, P}, title = {Efficacy of antibacterial agents combined with erbium laser and photodynamic therapy in reducing titanium biofilm vitality: an in vitro study.}, journal = {BMC oral health}, volume = {23}, number = {1}, pages = {32}, pmid = {36658553}, issn = {1472-6831}, abstract = {BACKGROUND AND OBJECTIVE: The emergence of peri-implant diseases has prompted various methods for decontaminating the implant surface. This study compared the effectiveness of three different approaches, chlorhexidine digluconate (CHX) combined with erbium-doped yttrium-aluminum-garnet (Er:YAG) laser, photodynamic therapy (PDT), and CHX only, for reducing biofilm vitality from implant-like titanium surfaces.<br><br>The study involved eight volunteers, each receiving a custom mouth device containing eight titanium discs. The volunteers were requested to wear the device for 72&#xa0;h for biofilm development. Fluorescence microscopy was used to evaluate the remaining biofilm with a two-component nucleic acid dye kit. The vital residual biofilm was quantified as a percentage of the surface area using image analysis software. Sixty-four titanium discs were assigned randomly to one of four treatment groups.<br><br>RESULTS: The percentage of titanium disc area covered by vital residual biofilm was 43.9% (7.7%), 32.2% (7.0%), 56.6% (3.6%), and 73.2% (7.8%) in the PDT, Er:YAG, CHX, and control groups, respectively (mean (SD)). Compared to the control group, the treatment groups showed significant differences in the area covered by residual biofilm (P&#x2009;<&#x2009;0.001). CHX combined with Er:YAG laser treatment was superior to CHX combined with PDT, and CHX only was better than the control.<br><br>CONCLUSION: Within the current in vitro model's limitations, CHX combined with Er:YAG laser treatment is a valid method to reduce biofilm vitality on titanium discs.}, }
@article {pmid36658257, year = {2023}, author = {Agrawal, S and Tipre, D and Dave, SR}, title = {Biotreatment of azo dye containing textile industry effluent by a developed bacterial consortium immobilised on brick pieces in an indigenously designed packed bed biofilm reactor.}, journal = {World journal of microbiology &amp; biotechnology}, volume = {39}, number = {3}, pages = {83}, pmid = {36658257}, issn = {1573-0972}, abstract = {This study highlights the development of a lab-scale, indigenously designed; Packed-Bed Biofilm Reactor (PBBR) packed with brick pieces. The developed biofilm in the reactor was used for the decolourisation and biodegradation of the textile industry effluent. The PBBR was continuously operated for 264 days, during which 301 cycles of batch and continuous treatment were operated. In batch mode under optimised conditions, more than 99% dye decolourisation and ≥ 92% COD reduction were achieved in 6 h of contact time upon supplementation of effluent with 0.25 g L[-1] glucose, 0.25 g L[-1] urea, and 0.1 g L[-1] phosphates. A decolourisation rate of 133.94 ADMI units h[-1] was achieved in the process. PBBR, when operated in continuous mode, showed ≥ 95% and ≥ 92% reduction in ADMI and COD values. Subsequent aeration and passage through the charcoal reactor assisted in achieving a ≥ 96% reduction in COD and ADMI values. An overall increase of 81% in dye-laden effluent decolourisation rate, from 62 to 262 mg L[-1] h[-1], was observed upon increasing the flow rate from 18 to 210 mL h[-1]. Dye biodegradation was determined by UV-Vis and FTIR spectroscopy and toxicity study. SEM analysis showed the morphology of the attached-growth biofilm.}, }
@article {pmid36658182, year = {2023}, author = {Pakkulnan, R and Thonglao, N and Chareonsudjai, S}, title = {DNase I and chitosan enhance efficacy of ceftazidime to eradicate Burkholderia pseudomallei biofilm cells.}, journal = {Scientific reports}, volume = {13}, number = {1}, pages = {1059}, pmid = {36658182}, issn = {2045-2322}, abstract = {Biofilm-associated Burkholderia pseudomallei infection contributes to antibiotic resistance and relapse of melioidosis. Burkholderia pseudomallei biofilm matrix contains extracellular DNA (eDNA) that is crucial for biofilm establishment. However, the contribution of eDNA to antibiotic resistance by B. pseudomallei remains unclear. In this study, we first demonstrated in vitro that DNase I with the administration of ceftazidime (CAZ) at 24 h considerably inhibited the 2-day biofilm formation and reduced the number of viable biofilm cells of clinical B. pseudomallei isolates compared to biofilm treated with CAZ alone. A 3-4 log reduction in numbers of viable cells embedded in the 2-day biofilm was observed when CAZ was combined with DNase I. Confocal laser-scanning microscope visualization emphasized the competence of DNase I followed by CAZ supplementation to significantly limit B. pseudomallei biofilm development and to eradicate viable embedded B. pseudomallei biofilm cells. Furthermore, DNase I supplemented with chitosan (CS) linked with CAZ (CS/CAZ) significantly eradicated shedding planktonic and biofilm cells. These findings indicated that DNase I effectively degraded eDNA leading to biofilm inhibition and dispersion, subsequently allowing CAZ and CS/CAZ to eradicate both shedding planktonic and embedded biofilm cells. These findings provide efficient strategies to interrupt biofilm formation and improve antibiotic susceptibility of biofilm-associated infections.}, }
@article {pmid36657584, year = {2023}, author = {Vladimir, M and Tatiana, R and Evgeniy, S and Veerasingam, S and Bagaev, A}, title = {Vertical and seasonal variations in biofilm formation on plastic substrates in coastal waters of the Black Sea.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {137843}, doi = {10.1016/j.chemosphere.2023.137843}, pmid = {36657584}, issn = {1879-1298}, abstract = {Plastic contamination of the marine environment is an increasing concern worldwide. Therefore, it is important to understand the kinetics of biofilms on plastics to study their behavior, fate, and transport pathways in the ocean. In this study, the vertical and seasonal variations in biofouling formation on transparent polyethylene terephthalate (PET) plastic fragments in the Southwest Crimea coastal waters of the Black Sea were investigated. Biofilms were identified in the transient light as 'dark spots' on the plastic surface, for which the numbers, size, and area were measured using specialized software. The rate of biofouling in the surface water layer was lower than those found in the middle and near-bottom water column, which could be due to a damaging effect of turbulent mixing on the biofilm. The highest rates of biofouling and diverse community were observed during the summer. The epibiotic assembly was represented by diatoms (11 taxa), dinoflagellates (3 taxa), green algae, filamentous cyanobacteria, small flagellates, and ciliates. Significant differences between the biofouling rates observed in different seasons made it difficult to estimate the period of time the plastic substrate has been in the marine environment. It was proposed to use the green alga Phycopeltis arundinacea (Montgn) De Tender et al., 2015 as a bioindicator to study the age of the biofouling community. Discoid thalli were identified at all stages of colonization of the plastic fragments in different seasons. Results obtained in this study demonstrate that biofouling organisms may be good model organisms in revealing age of biofilm formation and longevity of plastic debris in the ocean. Consequently, it is proposed that such biofouling organisms could be used as target species to monitor the biodegradation of plastic debris.}, }
@article {pmid36657551, year = {2023}, author = {Zhao, D and Li, X and Xu, M and Jiao, Y and Liu, H and Xiao, X and Zhao, H}, title = {Preparations of antibacterial yellow-green-fluorescent carbon dots and carbon dots-lysozyme complex and their applications in bacterial imaging and bacteria/biofilm inhibition/clearance.}, journal = {International journal of biological macromolecules}, volume = {}, number = {}, pages = {123303}, doi = {10.1016/j.ijbiomac.2023.123303}, pmid = {36657551}, issn = {1879-0003}, abstract = {The preparation of functional long-wavelength-emitting nanomaterials and the researches on their applications in antibacterial and antibiofilm fields have important significance. This paper reports the preparation of yellow-green-fluorescent and high- quantum yield carbon dots (4-ACDs) with 4-aminosalicylic acid and polyethylene imine as raw materials through one-step route, and the impacts of raw material structure and the reaction conditions upon the optical properties of the products have been investigated. 4-ACDs exhibit excellent broad-spectrum antibacterial activity, and their good biocompatibility ensures them as ideal fluorescent nano-probe for cell imaging. However, 4-ACDs could not effectively eliminate the biofilm of Staphylococcus aureus (S. aureus). CDs-LZM complex was prepared through the coupling between 4-ACDs and lysozyme (LZM) and the complex showed strong antibacterial activity against Gram-positive bacteria, particularly with MIC against S. aureus at 5 μg mL[-1]. Besides, CDs-LZM showed excellent ability against the biofilm of S. aureus. At the concentration of 60 μg mL[-1], its inhibition rate against the growth of biofilm was 86 %, and elimination rate against biofilm reached 76 %. CDs-LZM exhibited obvious antibiofilm ability through removing extracellular matrix of biofilm, greatly reducing the thickness of biofilm under confocal microscopy. The application of novel long-wavelength-emitting nanomaterial in eliminating pathogenic bacteria is of great significance.}, }
@article {pmid36657162, year = {2023}, author = {Lee, CW and Lin, ZC and Chiang, YC and Li, SY and Ciou, JJ and Liu, KW and Lin, YC and Huang, BJ and Peng, KT and Fang, ML and Lin, TE and Liao, MY and Lai, CH}, title = {AuAg nanocomposites suppress biofilm-induced inflammation in human osteoblasts.}, journal = {Nanotechnology}, volume = {}, number = {}, pages = {}, doi = {10.1088/1361-6528/acb4a1}, pmid = {36657162}, issn = {1361-6528}, abstract = {Staphylococcus aureus (S. aureus) forms biofilm that causes periprosthetic joint infections (PJIs) and osteomyelitis (OM) which are the intractable health problems in clinics. The silver-containing nanoparticles (AgNPs) are antibacterial nanomaterials with less cytotoxicity than the classic Ag compounds. Likewise, gold nanoparticles (AuNPs) have also been demonstrated as excellent nanomaterials for medical applications. Previous studies have showed that both AgNPs and AuNPs have anti-microbial or anti-inflammatory properties. We've developed a novel green chemistry that could generate the AuAg nanocomposites, through the reduction of tannic acid (TNA). The bioactivity of the nanocomposites was investigated in S. aureus biofilm-exposed human osteoblast cells (hFOB1.19). The current synthesis method is a simple, low-cost, eco-friendly, and green chemistry approach. Our results showed that the AuAg nanocomposites were biocompatible with low cell toxicity, and did not induce cell apoptosis nor necrosis in hFOB1.19 cells. Moreover, AuAg nanocomposites could effectively inhibited the accumulation of reactive oxygen species (ROS) in mitochondria and in rest of cellular compartments after exposing to bacterial biofilm (by reducing 0.78, 0.77-fold in the cell and mitochondria, respectively). AuAg nanocomposites also suppressed ROS-triggered inflammatory protein expression via MAPKs and Akt pathways. The current data suggest that AuAg nanocomposites have the potential to be a good therapeutic agent in treating inflammation in bacteria-infected bone diseases.}, }
@article {pmid36656902, year = {2023}, author = {Lee, H and Im, H and Hwang, SH and Ko, D and Choi, SH}, title = {Two novel genes identified by large-scale transcriptomic analysis are essential for biofilm and rugose colony development of Vibrio vulnificus.}, journal = {PLoS pathogens}, volume = {19}, number = {1}, pages = {e1011064}, doi = {10.1371/journal.ppat.1011064}, pmid = {36656902}, issn = {1553-7374}, abstract = {Many pathogenic bacteria form biofilms to survive under environmental stresses and host immune defenses. Differential expression (DE) analysis of the genes in biofilm and planktonic cells under a single condition, however, has limitations to identify the genes essential for biofilm formation. Independent component analysis (ICA), a machine learning algorithm, was adopted to comprehensively identify the biofilm genes of Vibrio vulnificus, a fulminating human pathogen, in this study. ICA analyzed the large-scale transcriptome data of V. vulnificus cells under various biofilm and planktonic conditions and then identified a total of 72 sets of independently co-regulated genes, iModulons. Among the three iModulons specifically activated in biofilm cells, BrpT-iModulon mainly consisted of known genes of the regulon of BrpT, a transcriptional regulator controlling biofilm formation of V. vulnificus. Interestingly, the BrpT-iModulon additionally contained two novel genes, VV1_3061 and VV2_1694, designated as cabH and brpN, respectively. cabH and brpN were shared in other Vibrio species and not yet identified by DE analyses. Genetic and biochemical analyses revealed that cabH and brpN are directly up-regulated by BrpT. The deletion of cabH and brpN impaired the robust biofilm and rugose colony formation. CabH, structurally similar to the previously known calcium-binding matrix protein CabA, was essential for attachment to the surface. BrpN, carrying an acyltransferase-3 domain as observed in BrpL, played an important role in exopolysaccharide production. Altogether, ICA identified two novel genes, cabH and brpN, which are regulated by BrpT and essential for the development of robust biofilms and rugose colonies of V. vulnificus.}, }
@article {pmid36656746, year = {2023}, author = {Brooks, JR and Chonko, D and Pigott, M and Sullivan, A and Moore, K and Stoodley, P}, title = {Mapping Bacterial Biofilm on Explanted Orthopaedic Hardware: An Analysis of 14 Consecutive Cases.}, journal = {APMIS : acta pathologica, microbiologica, et immunologica Scandinavica}, volume = {}, number = {}, pages = {}, doi = {10.1111/apm.13295}, pmid = {36656746}, issn = {1600-0463}, abstract = {BACKGROUND AND PURPOSE: Hardware implanted during primary total joint arthroplasty (TJA) carries a serious risk for periprosthetic joint infection (PJI). The formation of bacterial biofilms, which are highly tolerant of antibiotics and host immunity, is recognized as being a major barrier to treatment. It is not known if some components and their surface features are more prone to biofilm than others. This study attempted to map biofilm on different components and features of orthopedic hardware recovered during revision.<br><br>METHODS: Implant surface culture (ISC) was used on fifty-three components from fourteen hip and knee revisions. ISC achieves a thin agar coating over components, followed by incubation and observation for colony outgrowth over nine days. Recovered organisms were identified by selective culture and 16s rRNA sequencing. Outcomes were compared with clinical culturing and PJI diagnosis based on 2013 Musculoskeletal Infection Society criteria.<br><br>RESULTS: ISC paralleled clinical culturing with a sensitivity of 100% and specificity of 57.1%. When compared to MSIS criteria, sensitivity remained at 100% while specificity was 80%. Biofilm accumulation was patchy and heterogenous throughout different prostheses, though notably the non-articulating surfaces between the tibial tray and polyethylene insert showed consistent growth. On individual components, ridges and edges consistently harbored biofilm, while growth elsewhere was case-dependent.<br><br>INTERPRETATION: ISC successfully identified microbial growth with a high sensitivity while also revealing that biofilm growth was commonly localized to particular locations. Understanding where biofilm formation occurs most often on implanted hardware will help guide debridement, retention choices, and implant design.}, }
@article {pmid36656007, year = {2023}, author = {Goh, YF and Røder, HL and Chan, SH and Ismail, MH and Madsen, JS and Lee, KWK and Sørensen, SJ and Givskov, M and Burmølle, M and Rice, SA and McDougald, D}, title = {Associational Resistance to Predation by Protists in a Mixed Species Biofilm.}, journal = {Applied and environmental microbiology}, volume = {}, number = {}, pages = {e0174122}, doi = {10.1128/aem.01741-22}, pmid = {36656007}, issn = {1098-5336}, abstract = {Mixed species biofilms exhibit increased tolerance to numerous stresses compared to single species biofilms. The aim of this study was to examine the effect of grazing by the heterotrophic protist, Tetrahymena pyriformis, on a mixed species biofilm consisting of Pseudomonas aeruginosa, Pseudomonas protegens, and Klebsiella pneumoniae. Protozoan grazing significantly reduced the single species K. pneumoniae biofilm, and the single species P. protegens biofilm was also sensitive to grazing. In contrast, P. aeruginosa biofilms were resistant to predation. This resistance protected the otherwise sensitive members of the mixed species biofilm consortium. Rhamnolipids produced by P. aeruginosa were shown to be the primary toxic factor for T. pyriformis. However, a rhamnolipid-deficient mutant of P. aeruginosa (P. aeruginosa ΔrhlAB) maintained grazing resistance in the biofilm, suggesting the presence of at least one additional protective mechanism. P. aeruginosa with a deleted gene encoding the type III secretion system also resisted grazing. A transposon library was generated in the ΔrhlAB mutant to identify the additional factor involved in community biofilm protection. Results indicated that the Pseudomonas Quinolone Signal (PQS), a quorum sensing signaling molecule, was likely responsible for this effect. We confirmed this observation by showing that double mutants of ΔrhlAB and genes in the PQS biosynthetic operon lost grazing protection. We also showed that PQS was directly toxic to T. pyriformis. This study demonstrates that residing in a mixed species biofilm can be an advantageous strategy for grazing sensitive bacterial species, as P. aeruginosa confers community protection from protozoan grazing through multiple mechanisms. IMPORTANCE Biofilms have been shown to protect bacterial cells from predation by protists. Biofilm studies have traditionally used single species systems, which have provided information on the mechanisms and regulation of biofilm formation and dispersal, and the effects of predation on these biofilms. However, biofilms in nature are comprised of multiple species. To better understand how multispecies biofilms are impacted by predation, a model mixed-species biofilm was here exposed to protozoan predation. We show that the grazing sensitive strains K. pneumonia and P. protogens gained associational resistance from the grazing resistant P. aeruginosa. Resistance was due to the secretion of rhamnolipids and quorum sensing molecule PQS. This work highlights the importance of using mixed species systems.}, }
@article {pmid36655713, year = {2023}, author = {Römling, U}, title = {Is biofilm formation intrinsic to the origin of life?.}, journal = {Environmental microbiology}, volume = {25}, number = {1}, pages = {26-39}, doi = {10.1111/1462-2920.16179}, pmid = {36655713}, issn = {1462-2920}, abstract = {Biofilms are multicellular, often surface-associated, communities of autonomous cells. Their formation is the natural mode of growth of up to 80% of microorganisms living on this planet. Biofilms refractory towards antimicrobial agents and the actions of the immune system due to their tolerance against multiple environmental stresses. But how did biofilm formation arise? Here, I argue that the biofilm lifestyle has its foundation already in the fundamental, surface-triggered chemical reactions and energy preserving mechanisms that enabled the development of life on earth. Subsequently, prototypical biofilm formation has evolved and diversified concomitantly in composition, cell morphology and regulation with the expansion of prokaryotic organisms and their radiation by occupation of diverse ecological niches. This ancient origin of biofilm formation thus mirrors the harnessing environmental conditions that have been the rule rather than the exception in microbial life. The subsequent emergence of the association of microbes, including recent human pathogens, with higher organisms can be considered as the entry into a nutritional and largely stress-protecting heaven. Nevertheless, basic mechanisms of biofilm formation have surprisingly been conserved and refunctionalized to promote sustained survival in new environments.}, }
@article {pmid36655001, year = {2023}, author = {Johnston, W and Ware, A and Kuiters, WF and Delaney, C and Brown, JL and Hagen, S and Corcoran, D and Cummings, M and Ramage, G and Kean, R}, title = {In vitro bacterial vaginosis biofilm community manipulation using endolysin therapy.}, journal = {Biofilm}, volume = {5}, number = {}, pages = {100101}, pmid = {36655001}, issn = {2590-2075}, abstract = {Bacterial vaginosis (BV) affects approximately 26% of women of childbearing age globally, presenting with 3-5 times increased risk of miscarriage and two-fold risk of pre-term birth. Antibiotics (metronidazole and clindamycin) are typically employed to treat BV; however the success rate is low due to the formation of recalcitrant polymicrobial biofilms. As a novel therapeutic, promising results have been obtained in vitro using Gardnerella endolysins, although to date their efficacy has only been demonstrated against simple biofilm models. In this study, a four-species biofilm was developed consisting of Gardnerella vaginalis, Fannyhessea vaginae, Prevotella bivia and Mobiluncus curtisii. Biofilms were grown in NYC III broth and treated using antibiotics and an anti-Gardnerella endolysin (CCB7.1) for 24 h. Biofilm composition, viability and structure were assessed using colony counts, live/dead qPCR and scanning electron microscopy. All species colonised biofilms to varying degrees, with G. vaginalis being the most abundant. Biofilm composition remained largely unchanged when challenged with escalated concentrations of conventional antibiotics. A Gardnerella-targeted endolysin candidate (CCB7.1) showed efficacy against several Gardnerella species planktonically, and significantly reduced viable G. vaginalis within polymicrobial biofilms at 1 to 4X pMIC (p < 0.05 vs. vehicle control). Collectively, this study highlights the resilience of biofilm-embedded pathogens against the currently used antibiotics and provides a polymicrobial model that allows for more effective pre-clinical screening of BV therapies. The Gardnerella-specific endolysin CCB7.1 demonstrated significant activity against G. vaginalis within polymicrobial biofilms, altering the overall community dynamic and composition.}, }
@article {pmid36651814, year = {2023}, author = {Zhang, X and Zheng, L and Lu, Z and Zhou, L and Meng, F and Shi, C and Bie, X}, title = {Biochemical and molecular regulatory mechanism of the pgpH gene on biofilm formation in Listeria monocytogenes.}, journal = {Journal of applied microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1093/jambio/lxac086}, pmid = {36651814}, issn = {1365-2672}, abstract = {AIMS: PgpH gene has an important regulatory role on bacterial physiological activity, but studies on its regulation mechanism on biofilm formation of Listeria monocytogenes are lacking. Our aim was to investigate the effect of pgpH gene deletion on biofilm formation in L. monocytogenes.<br><br>METHODS AND RESULTS: The &#x394;pgpH deletion strain of L. monocytogenes LMB 33426 was constructed by homologous recombination. Deletion of the pgpH gene resulted in a significant reduction in biofilm formation. The swimming ability of the &#x394;pgpH strain on semisolid plates was unchanged compared to the wild-type strain (WT), and the auto-aggregation capacity of L. monocytogenes was decreased. RNA-seq showed that &#x394;pgpH resulted in the differential expression of 2357 genes compared to WT. pgpH inactivation resulted in the significant downregulation of the cell wall formation-related genes dltC, dltD, walK, and walR and the flagellar assembly-related genes fliG and motB.<br><br>CONCLUSIONS: This study shows that the deletion of pgpH gene regulates biofilm formation and auto-aggregation ability of L. monocytogenes by affecting the expression of flagellar assembly and cell wall related genes. pgpH has a global regulatory effect on biofilm formation in L. monocytogenes.}, }
@article {pmid36651450, year = {2023}, author = {Barbosa, DHX and Gondim, CR and Silva-Henriques, MQ and Soares, CS and Alves, DN and Santos, SG and Castro, RD}, title = {Coriandrum sativum L. essential oil obtained from organic culture shows antifungal activity against planktonic and multi-biofilm Candida.}, journal = {Brazilian journal of biology = Revista brasleira de biologia}, volume = {83}, number = {}, pages = {e264875}, doi = {10.1590/1519-6984.264875}, pmid = {36651450}, issn = {1678-4375}, abstract = {This study aimed to analyze the phytochemical profile of essential oil obtained from the leaves of Coriandrum sativum L., and its antifungal activity against Candida spp. The research consisted of an in vitro study including collecting the vegetable product, analysis of its macronutrients, extraction, and chemical analysis of the essential oil, and assaying antifungal activity through minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), with growth inhibition kinetics, and the product's effects on multi-species Candida biofilm. Nitrogen (47.08 g Kg-1), phosphorus (5.3 g Kg-1) and potassium (50.46 g Kg-1) levels were within the normal range. The major constituents were octanal, decanal, dec-(2E)-enal, and dodecanal. The MIC and MFC of the product evaluated against 11 tested Candida strains ranged from 31.25 to 250 μg/mL. There was inhibition of fungal growth during 24 hours of exposure at the 3 concentrations tested (250, 125, and 62.5 μg/mL). The concentration of 80 mg/mL promoted the greatest reduction in multispecies biofilm (70% reduction in biofilm). Coriandrum sativum L. essential oil extract is principally constituted of alcohols and aldehydes and presents fungicidal activity against Candida spp. in its in planktonic and biofilm forms.}, }
@article {pmid36649516, year = {2023}, author = {Mohammadinejat, M and Sepahi, AA and Alipour, E}, title = {Antibacterial and Anti-Biofilm Activities of Silver Nano Particles Conjugated to Chitosan Against Multi-Drug Resistant Bacteria.}, journal = {Clinical laboratory}, volume = {69}, number = {1}, pages = {}, doi = {10.7754/Clin.Lab.2022.220315}, pmid = {36649516}, issn = {1433-6510}, abstract = {BACKGROUND: Nowadays, most of the traditional and conventional antibiotics are not effective against drug resistant bacterial strains. The emergence and spread of drug resistant bacterial cells calls for new therapeutic agents and strategies to control and treat the infections caused by these bacteria. In this regard, the application of nano-technology in medicine is an interesting approach. Therefore, the aim of this study was to evaluate the antibacterial and anti-biofilm activities of Ag Np conjugated to chitosan against multidrug resistant isolates of Staphylococcus aureus and Acinetobacter baumannii.<br><br>METHODS: Synthesis of the Ag Np and chitosan Np were performed according to the Turkevich and Ionic gelation methods, respectively. Then conjugation of nanoparticles was carried out by standard method. FTR analysis and transmission electron microscopy were used for validation of nanoparticle conjugation. Twenty clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and 20 clinical isolates of carbapenem resistant Acinetobacter baumannii (CRAB) were obtained from the microbial bank of Imam Khomeini hospital of Tehran, Iran. MIC values of the nanoparticles alone and in conjugation were determined using the microbroth dilution method. Then, fractional inhibitory concentration of agents was concluded by standard method. Finally, anti-biofilm activities of the conjugated Ag Np-chitosan at sub-MIC concentrations was tested against bacterial isolates.<br><br>RESULTS: Synthesis of Ag Np resulted in the formation of nanoparticles with 10 nm dimensions. MIC90 of the chitosan, Ag Np and their conjugated form were respectively 64, 16, and 8 &#x3bc;g/mL against CRAB isolates. Also, MIC90 of the tested agents, in the same order as mentioned above, were 32, 16, and 4 &#x3bc;g/mL against MRSA. Combination of the agents had additive (0.625) and synergistic (0.375) effects against CRAB and MRSA. Ability of biofilm formation was dramatically reduced by &#xbc; MIC concentration (2 &#x3bc;g/mL) against the CRAB and &#xbd; MIC concentration (2 &#x3bc;g/mL) in the case of the MRSA isolates.<br><br>CONCLUSIONS: Ag Np-chitosan conjugation, an ideal alternative for ineffective antibiotics, exhibits great antibacterial and anti-biofilm effects against CRAB and MRSA isolates.}, }
@article {pmid36649038, year = {2022}, author = {Whelan, S and O'Grady, MC and Corcoran, GD and Finn, K and Lucey, B}, title = {Effect of Sub-Inhibitory Concentrations of Nitrofurantoin, Ciprofloxacin, and Trimethoprim on In Vitro Biofilm Formation in Uropathogenic Escherichia coli (UPEC).}, journal = {Medical sciences (Basel, Switzerland)}, volume = {11}, number = {1}, pages = {}, doi = {10.3390/medsci11010001}, pmid = {36649038}, issn = {2076-3271}, abstract = {The purpose of this study was to determine the effect of sublethal concentrations of nitrofurantoin, ciprofloxacin, and trimethoprim on biofilm formation in 57 uropathogenic Escherichia coli strains (UPEC). The minimum inhibitory concentration of nitrofurantoin, ciprofloxacin, and trimethoprim was determined and the biofilm formation for each isolate with and without sub-lethal concentrations of each antibiotic was then quantified. The statistical significance of changes in biofilm formation was ascertained by way of a Dunnett's test. A total of 22.8% of strains were induced to form stronger biofilms by nitrofurantoin, 12% by ciprofloxacin, and 19% by trimethoprim; conversely 36.8% of strains had inhibited biofilm formation with nitrofurantoin, 52.6% with ciprofloxacin, and 38.5% with trimethoprim. A key finding was that even in cases where the isolate was resistant to an antibiotic as defined by EUCAST, many were induced to form a stronger biofilm when grown with sub-MIC concentrations of antibiotics, especially trimethoprim, where six of the 22 trimethoprim resistant strains were induced to form stronger biofilms. These findings suggest that the use of empirical treatment with trimethoprim without first establishing susceptibility may in fact potentiate infection in cases where a patient who is suffering from a urinary tract infection (UTI) caused by trimethoprim resistant UPEC is administered trimethoprim. This emphasizes the need for laboratory-guided treatment of UTI.}, }
@article {pmid36648441, year = {2023}, author = {Pezolt, C and Karau, A and Schobert, R and Schrey, H}, title = {Syntheses and Biofilm Reducing Effects of l-Dopa-Derived Analogues of the Fungal Macrocidins A and Z.}, journal = {Chemistry (Weinheim an der Bergstrasse, Germany)}, volume = {}, number = {}, pages = {}, doi = {10.1002/chem.202203647}, pmid = {36648441}, issn = {1521-3765}, abstract = {Four analogues of the fungal metabolites macrocidin A and Z, featuring [13]para- or [13]metacyclophanes, were synthesised from fully and orthogonally protected l-dopa instead of l-tyrosine. They were tested for antibiotic activities and for effects on the growth and persistence of microbial biofilms. Tentative structure-activity relationships and distinct differences when compared with the natural lead compounds were identified.}, }
@article {pmid36645660, year = {2022}, author = {Myntti, MF and Stevenson, P and Porral, D and Hayes, VY}, title = {The effect of a biofilm-disrupting wound gel vs. a broad-spectrum antimicrobial ointment on a chronic wound microbiome: a secondary analysis associating clinical and laboratory findings.}, journal = {Wounds : a compendium of clinical research and practice}, volume = {34}, number = {12}, pages = {E141-E146}, pmid = {36645660}, issn = {1943-2704}, abstract = {INTRODUCTION: Advancement in wound bioburden diagnostics continues to evolve highlighting the need to link laboratory findings to clinical practice.<br><br>OBJECTIVE: This study aims to determine if laboratory data from a previously published study supports a correlation between use of a novel biofilm-disrupting wound gel and lower bacterial bioburden, wound size reduction, and improved healing.<br><br>MATERIALS AND METHODS: This is a secondary data analysis of a multicenter, prospective, randomized, open-label clinical trial performed from September 2014 through March 2016. The trial compares treatment outcomes of standard of care either with a wound gel (experimental) or triple-antibiotic maximum-strength ointment (control) looking at differences in bioburden measured at time zero (baseline) and after 4 weeks of treatment. Quantitative real-time PCR testing for bacteria and fungi, including testing for resistance factors to vancomycin and methicillin or using proprietary genetic sequencing, was used for analysis.<br><br>RESULTS: Low or medium bacterial load at baseline correlated to an average reduction in wound size of 40% and 24%, respectively, whereas there was a 19% increase in size among wounds with a high bioburden.<br><br>CONCLUSION: Reducing wound bioburden could result in a clinically relevant change in the healing trajectory. In this study, wound size reduction and increased healing percentages were superior in the experimental group.}, }
@article {pmid36645278, year = {2023}, author = {Liu, J and Chang, Z and Chang, X and Li, J and Glebe, U and Jia, AQ}, title = {Combination of 2-tert-Butyl-1,4-Benzoquinone (TBQ) and ZnO Nanoparticles, a New Strategy To Inhibit Biofilm Formation and Virulence Factors of Chromobacterium violaceum.}, journal = {mSphere}, volume = {}, number = {}, pages = {e0059722}, doi = {10.1128/msphere.00597-22}, pmid = {36645278}, issn = {2379-5042}, abstract = {Drug-resistant bacteria have been raising serious social problems. Bacterial biofilms and different virulence factors are the main reasons for persistent infections. As a conditioned pathogen, Chromobacterium violaceum has evolved a vast network of regulatory mechanisms to modify and fine-tune biofilm development, contributing to multidrug resistance. However, there are few therapies to combat drug-resistant bacteria. Quorum sensing (QS) inhibitors (QSIs) are a promising strategy to solve antibiotic resistance. Our previous work suggested that 2-tert-butyl-1,4-benzoquinone (TBQ) is a potent QSI. In this study, the combination of zinc oxide nanoparticles (ZnO-NPs) and TBQ (ZnO-TBQ) was investigated for the treatment of Chromobacterium violaceum ATCC 12472 infection. ZnO-NPs attach to cell walls or biofilms, and the local dissolution of ZnO-NPs can lead to increased Zn[2+] concentrations, which could destroy metal homeostasis, corresponding to disturbances in amino acid metabolism and nucleic acid metabolism. ZnO-NPs significantly improved the efficiency of TBQ in inhibiting the QS-related virulence factors and biofilm formation of C. violaceum ATCC 12472. ZnO-TBQ effectively reduces the expression of genes related to QS, which is conducive to limiting the infectivity of C. violaceum ATCC 12472. Caenorhabditis elegans nematodes treated with ZnO-TBQ presented a significant improvement in the survival rate by 46.7%. Overall, the combination of ZnO-NPs and TBQ offers a new strategy to attenuate virulence factors and biofilm formation synergistically in some drug-resistant bacteria. IMPORTANCE The combination of ZnO-NPs and TBQ (ZnO-TBQ) can compete with the inducer N-decanoyl-homoserine lactone (C10-HSL) by binding to CviR and downregulate genes related to the CviI/CviR system to interrupt the QS system of C. violaceum ATCC 12472. The downstream genes responding to cviR were also downregulated so that virulence factors and biofilm formation were inhibited. Furthermore, ZnO-TBQ presents multiple metabolic disturbances in C. violaceum ATCC 12472, which results in the reduced multidrug resistance and pathogenicity of C. violaceum ATCC 12472. In an in vivo assay, C. elegans nematodes treated with ZnO-TBQ presented a significant improvement in the survival rate by 46.7% by limiting the infectivity of C. violaceum ATCC 12472. In addition, ZnO-TBQ inhibited the generation of virulence factors and biofilm formation 2-fold compared to either ZnO-NPs or TBQ alone. The combination of ZnO-NPs with TBQ offers a potent synergistic strategy to reduce multidrug resistance and pathogenicity.}, }
@article {pmid36644897, year = {2023}, author = {He, Z and Xu, X and Wang, C and Li, Y and Dong, B and Li, S and Zeng, J}, title = {Effect of Panax quinquefolius extract on Mycobacterium abscessus biofilm formation.}, journal = {Biofouling}, volume = {}, number = {}, pages = {1-12}, doi = {10.1080/08927014.2023.2166405}, pmid = {36644897}, issn = {1029-2454}, abstract = {Mycobacterium abscessus (M. abscessus) can exist either as planktonic bacteria or as a biofilm. Biofilm formation is one of the important causes of conversion to resistance to antibiotics of bacteria that were previously sensitive when in their planktonic form, resulting in infections difficult to manage. Panax quinquefolius and its active ingredient ginsenosides have the potential ability in fighting pathogenic infections. In this study, the P. quinquefolius extract (PQE) showed good antibacterial/bactericidal activity against the M. abscessus planktonic cells. The extract reduced the biomass, thickness, and number of M. abscessus in the biofilm and altered its morphological characteristics as well as the spatial distribution of dead/alive bacteria. Moreover, the ginsenoside CK monomer had a similar inhibitory effect on M. abscessus planktonic bacteria and biofilm formation. Therefore, PQE and its monomer CK might be potential novel antimicrobial agents for the clinical prevention and treatment of M. abscessus, including biofilms in chronic infections.}, }
@article {pmid36644335, year = {2023}, author = {Saud, B and Khatri, G and Amatya, N and Paudel, G and Shrestha, V}, title = {Methicillin-Resistant and Biofilm-Producing Staphylococcus aureus in Nasal Carriage among Health Care Workers and Medical Students.}, journal = {The Canadian journal of infectious diseases &amp; medical microbiology = Journal canadien des maladies infectieuses et de la microbiologie medicale}, volume = {2023}, number = {}, pages = {8424486}, pmid = {36644335}, issn = {1712-9532}, abstract = {Antimicrobial resistance (AMR) is a global threat. It has been portrayed as a slow tsunami. Multidrug resistance and extensive drug resistance exacerbate the already-existing AMR problem. The aim of the study was to access the colonization of methicillin-resistant and biofilm-producing Staphylococcus aureus among healthcare workers (HCWs) and medical students (MSs). A cross-sectional study was designed. A total of 352 participants (176 were HCWs and 176 were MSs) were enrolled from different hospitals and medical colleges in Kathmandu, Nepal. Nasal cavity swab samples were collected and inoculated on Mannitol salt agar at standard in-vitro environmental conditions. Isolates were identified based on colony characteristics, staining properties, and biochemical tests. Identified isolates were tested for antibiotic susceptibility and biofilm production. Out of 352 participants, 65.3% were S. aureus carriers; among the carriers, 52.2% were HCWs and 47.8% were MSs. Of the total isolates, 47.4% isolates were methicillin-resistant S. aureus (MRSA) and 73.9% isolates were multidrug-resistant (MDR). Among MDR isolates, out of 109 MRSA isolates, 86.2% were MDR and out of 121 MSSA isolates, 62.8% were MDR where isolates were mainly resistant to erythromycin. In addition, 68.7% isolates were biofilm-forming; the results were similar in both MRSA and MSSA. Variables such as profession and educational level showed statistical significance (p < 0.05) with MRSA, MSSA, and biofilm producers. In conclusion, asymptomatic colonization of healthcare workers by drug-resistant S. aureus is increasing at alarming rates. This reflects the lack of proper hygiene practice as well as improper disinfection of workplace of study population.}, }
@article {pmid36643518, year = {2023}, author = {Akbar, MU and Haque, A and Liaquat, S and Schierack, P and Ali, A}, title = {Biofilm Formation by Staphylococcus epidermidis and Its Inhibition Using Carvacrol, 2-Aminobenzemidazole, and 3-Indole Acetonitrile.}, journal = {ACS omega}, volume = {8}, number = {1}, pages = {682-687}, pmid = {36643518}, issn = {2470-1343}, abstract = {Biofilm-associated bacterial infections are problematic for physicians due to high antimicrobial resistance in biofilm-forming bacteria. Staphylococcus species, particularly Staphylococcus epidermidis, cause severe infections particularly associated with clinical implants. In this study, we have detected the biofilm formation potential of clinical S. epidermidis isolates using phenotypic and genotypic approaches in nutrient-rich and nutrient-deficient growth conditions. The Congo red agar method determined the biofilm formation potential with limited efficacy. However, the tissue culture plate method adroitly classified the isolates as strong, moderate, weak, and non-biofilm producers with five (10%) of the isolates as strong biofilm producers. Ten biofilm-associated genes were targeted, and the fruA gene was found to be the most prevalent (20%). Three antibiofilm compounds, carvacrol, 2-aminobenzemidazole, and 3-indole acetonitrile, were assessed against strong biofilm-producing S. epidermidis isolates. To the best of our knowledge, this is the first report of genotypic and phenotypic detection of biofilms formed by clinical S. epidermidis isolates from this region. The use of 3-indole acetonitrile against these biofilms and toluene as a solvent is novel. The study highlights the significance of biofilm and antibiofilm potential of the studied compounds for effective treatment and control of S. epidermidis infections.}, }
@article {pmid36643262, year = {2023}, author = {Kim, HJ and Yoo, HJ}, title = {Inhibitory effects of Streptococcus salivarius K12 on formation of cariogenic biofilm.}, journal = {Journal of dental sciences}, volume = {18}, number = {1}, pages = {65-72}, pmid = {36643262}, issn = {2213-8862}, abstract = {BACGROUND/PURPOSE: Streptococcus salivarius (S. salivarius) K12 is known to be a probiotic bacterium. The purpose of this study was to investigate anti-cariogenic effects of S. salivarius K12 on cariogenic biofilm.<br><br>MATERIALS AND METHODS: S. salivarius K12 was cultured in M17 broth. The antimicrobial activity of spent culture medium (SCM) against Streptococcus mutans was investigated. S. salivarius K12 was co-cultivated with S. mutans using a membrane insert. When the biofilm was formed using salivary bacteria and S. mutans, the K12 was inoculated every day. The biomass of biofilm was investigated by a confocal laser scanning microscope. Also, bacterial DNA from the biofilm was extracted, and then bacteria proportion was analyzed by quantitative PCR using specific primers. The expression of gtf genes of S. mutans in the biofilm with or without S. salivarius K12 was analyzed by RT-PCR.<br><br>RESULTS: The SCM of S. salivarius K12 inhibited the growth of S. mutans. Also, S. salivarius K12 reduced S. mutans growth in co-cultivation. The formation of cariogenic biofilm was reduced by adding S. salivarius K12, and the count of S. mutans in the biofilm was also decreased in the presence of S. salivarius K12. gtfB, gtfC, and gtfD expression of S. mutans in the biofilm was reduced in the presence of S. salivarius K12.<br><br>CONCLUSION: S. salivarius K12 may inhibit the formation of cariogenic biofilm by interrupting the growth and glucosyltransferase production of S. mutans.}, }
@article {pmid36642286, year = {2023}, author = {Yang, Y and Li, W and Li, Y and Shi, W and Zhang, J and Dang, W and Zhang, W}, title = {Exogenous c-di-GMP inhibited the biofilm formation of Vibrio splendidus.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {105981}, doi = {10.1016/j.micpath.2023.105981}, pmid = {36642286}, issn = {1096-1208}, abstract = {Vibrio splendidus, a gram-negative bacterium that is ubiquitously present in marine environments, has been increasingly deemed an important opportunistic pathogen of marine animals. In this study, the biofilm formation of V. splendidus was quantitatively determined and morphologically characterized. Three stages of biofilm formation, including adhesion, aggregation and maturation were observed in the biofilm formed by V. splendidus. The inhibitory effect of exogenous bis (3',5')-cyclic dimeric guanosine monophosphate (c-di-GMP) on the biofilm formation from the scratch and preformed established biofilms of V. splendidus was determined. When 200 μmol/L c-di-GMP was added, the quantity of biofilm decreased by 88.1% or 66.7% under the two conditions. To explore the preliminary mechanism of exogenous c-di-GMP on the biofilm formed by V. splendidus, proteomic analysis was performed. GO enrichment analysis showed that exogenous c-di-GMP upregulated biological processes, including the tricarboxylic acid cycle, oxidation‒reduction reactions and organonitrogen compound catabolism and significantly downregulated tRNA threonylcarbamoyladenosine modification, protein dephosphorylation, and lactate transmembrane transporter activity. Sequence-specific DNA binding activity was the most markedly downregulated molecular function. KEGG analysis showed that the valine, leucine and isoleucine degradation pathway was the most enriched pathway, followed by nitrogen metabolism, among the 20 upregulated pathways. Among the downregulated pathways, a nonribosomal peptide structure pathway and the streptomycine, polyketide sugar unit, acarbose and validamycin biosynthesis pathways were significantly enriched. Our present study provides basic data for the biofilm formation of V. splendidus and the preliminary inhibitory mechanism of exogenous c-di-GMP on the biofilm formation of V. splendidus.}, }
@article {pmid36642133, year = {2023}, author = {Thakur, K and Kuthiala, T and Singh, G and Arya, SK and Iwai, CB and Ravindran, B and Khoo, KS and Chang, SW and Awasthi, MK}, title = {An alternative approach towards nitrification and bioremediation of wastewater from aquaponics using biofilm-based bioreactors: A review.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {137849}, doi = {10.1016/j.chemosphere.2023.137849}, pmid = {36642133}, issn = {1879-1298}, abstract = {Aquaponics combines the advantages of aquaculture and hydroponics as it suits the urban environment where a lack of agricultural land and water resources is observed. It is an ecologically sound system that completely reuses its system waste as plant fertilizer. It offers sustainable water savings, making it a supreme technology for food production. The two major processes that hold the system together are nitrification and denitrification. The remains of fish in form of ammonia reach the bio filters where it is converted into nitrite and further into nitrate in presence of nitrifying and denitrifying bacteria. Nitrate eventually is taken up by the plants. However, even after the uptake from the flow stream, the effluent contains remaining ammonium and nitrates, which cannot be directly released into the environment. In this review it is suggested how integrating the biofilm-based bioreactors in addition to aquaculture and hydroponics eliminates the possibility of remains of total ammonia nitrogen [TAN] contents, leading to bioremediation of effluent water from the system. Effluent water after releasing from a bioreactor can be reused in an aquaculture system, conditions provided in these bioreactors promote the growth of required bacteria and encourages the mutual development of plants and fishes and eventually leading to bioremediation of wastewater from aquaponics.}, }
@article {pmid36641476, year = {2023}, author = {Saeed, SI and Vivian, L and Zalati, CWSCW and Sani, NIM and Aklilu, E and Mohamad, M and Noor, AAM and Muthoosamy, K and Kamaruzzaman, NF}, title = {Antimicrobial activities of graphene oxide against biofilm and intracellular Staphylococcus aureus isolated from bovine mastitis.}, journal = {BMC veterinary research}, volume = {19}, number = {1}, pages = {10}, pmid = {36641476}, issn = {1746-6148}, abstract = {BACKGROUND: S. aureus is one of the causative agents of bovine mastitis. The treatment using conventional antimicrobials has been hampered due to the development of antimicrobial resistance and the ability of the bacteria to form biofilms and localize inside the host cells.<br><br>OBJECTIVES: Here, the efficacy of graphene oxide (GO), a carbon-based nanomaterial, was tested against the biofilms and intracellular S. aureus invitro. Following that, the mechanism for the intracellular antimicrobial activities and GO toxicities was elucidated.<br><br>METHODS: GO antibiofilm properties were evaluated based on the disruption of biofilm structure, and the intracellular antimicrobial activities were determined by the survival of S. aureus in infected bovine mammary cells following GO exposure. The mechanism for GO intracellular antimicrobial activities was investigated using endocytosis inhibitors. GO toxicity towards the host cells was assessed using a resazurin assay.<br><br>RESULTS: At 100&#x2009;ug/mL, GO reduced between 30 and 70% of S. aureus biofilm mass, suggesting GO's ability to disrupt the biofilm structure. At 200&#x2009;ug/mL, GO killed almost 80% of intracellular S. aureus, and the antimicrobial activities were inhibited when cells were pre-treated with cytochalasin D, suggesting GO intracellular antimicrobial activities were dependent on the actin-polymerization of the cell membrane. At <&#x2009;250&#x2009;ug/mL, GO enhanced the viability of the Mac-T cell, and cells were only affected at higher dosages.<br><br>CONCLUSION: The in vitro efficacy of GO against S. aureus in vitro suggested the compound could be further tested in Vivo to zrecognize its potential as one of the components of bovine mastitis therapy.}, }
@article {pmid36641190, year = {2023}, author = {Gilmour, KA and Aljannat, M and Markwell, C and James, P and Scott, J and Jiang, Y and Torun, H and Dade-Robertson, M and Zhang, M}, title = {Biofilm inspired fabrication of functional bacterial cellulose through ex-situ and in-situ approaches.}, journal = {Carbohydrate polymers}, volume = {304}, number = {}, pages = {120482}, doi = {10.1016/j.carbpol.2022.120482}, pmid = {36641190}, issn = {1879-1344}, abstract = {Bacterial cellulose (BC) has been explored for use in a range of applications including tissue engineering and textiles. BC can be produced from waste streams, but sustainable approaches are needed for functionalisation. To this end, BslA, a B. subtilis biofilm protein was produced recombinantly with and without a cellulose binding module (CBM) and the cell free extract was used to treat BC either ex-situ, through drip coating or in-situ, by incorporating during fermentation. The results showed that ex-situ modified BC increased the hydrophobicity and water contact angle reached 120°. In-situ experiments led to a BC film morphological change and mechanical testing demonstrated that addition of BslA with CBM resulted in a stronger, more elastic material. This study presents a nature inspired approach to functionalise BC using a biofilm hydrophobin, and we demonstrate that recombinant proteins could be effective and sustainable molecules for functionalisation of BC materials.}, }
@article {pmid36640857, year = {2023}, author = {Bahrami, R and Pourhajibagher, M and Parker, S and Esmaeili, D and Bahador, A}, title = {Anti-biofilm and bystander effects of antimicrobial photo-sonodynamic therapy against polymicrobial periopathogenic biofilms formed on coated orthodontic mini-screws with zinc oxide nanoparticles.}, journal = {Photodiagnosis and photodynamic therapy}, volume = {}, number = {}, pages = {103288}, doi = {10.1016/j.pdpdt.2023.103288}, pmid = {36640857}, issn = {1873-1597}, abstract = {BACKGROUND: The present study evaluated the anti-biofilm and bystander effects of antimicrobial photo-sonodynamic therapy (aPSDT) on the polymicrobial periopathogenic biofilms formed on mini-screws coated with zinc oxide nanoparticles (ZnONPs).<br><br>MATERIALS AND METHODS: Thirty orthodontic identical mini-screws were divided into 6 groups (n&#x202f;=&#x202f;5) as follows: 1. negative control: uncoated mini-screw&#x202f;+&#x202f;phosphate-buffered saline (PBS), 2. positive control: uncoated mini-screw&#x202f;+&#x202f;0.2% CHX, 3. coating control: coated mini-screw&#x202f;+&#x202f;PBS, 4. antimicrobial photodynamic therapy (aPDT): coated mini-screw+light emitting diode (LED), 5. Antimicrobial sonodynamic therapy (aSDT): coated mini-screw+ultrasound waves, and 6. aPSDT: coated mini-screw+LED+ultrasound waves. Electrostatic spray-assisted vapor deposition was employed to coat ZnONPs on titanium mini-screws. The biofilm inhibition test was used to assess the anti-biofilm efficacy against polymicrobial periopathogenic biofilms including Porphyromonas gingivitis, Prevotella intermedia, and Aggregatibacter actinomycetemcomitans, and the results were shown as the percent reduction of Log10 colony-forming unit (CFU)/mL. Following each treatment, the gene expression levels of TNF-&#x3b1;, IL-1&#x3b2;, and IL-6 were evaluated on human gingival fibroblast (HGF) cells via&#xa0;quantitative real-time polymerase chain reaction (qRT-PCR) to reveal the bystander effects of aPSDT on HGF cells.<br><br>RESULTS: A significant reduction in log10 CFU/mL of periopathogens was observed in groups treated with aPDT, aSDT, aPSDT, and 0.2% CHX up to 6.81, 6.63, 5.02, and 4.83 log, respectively, when compared with control groups (P<0.05). 0.2% CHX and aPSDT groups demonstrated significantly higher capacity in eliminating the periopathogen biofilm compared with other groups (P<0.05). The qRT-PCR showed that the expression level of inflammatory cytokines was significantly down regulated in aPDT, aSDT, and aPSDT groups (P<0.05).<br><br>CONCLUSION: It was found that the ZnONPs-mediated aPSDT could significantly reduce periopathogen biofilm as well as the expression level of inflammatory cytokines.}, }
@article {pmid36640262, year = {2023}, author = {Strateva, T and Trifonova, A and Sirakov, I and Borisova, D and Stancheva, M and Keuleyan, E and Setchanova, L and Peykov, S}, title = {Analysis of biofilm formation in nosocomial Stenotrophomonas maltophilia isolates collected in Bulgaria: An 11-year study (2011-2022).}, journal = {Acta microbiologica et immunologica Hungarica}, volume = {}, number = {}, pages = {}, doi = {10.1556/030.2023.01920}, pmid = {36640262}, issn = {1588-2640}, abstract = {The present study aimed to explore the genotypic and phenotypic characteristics of biofilm formation in Bulgarian nosocomial Stenotrophomonas maltophilia isolates (n = 221) during the period 2011-2022, by screening for the presence of biofilm-associated genes (BAG) (spgM, rmlA and rpfF), their mutational variability, and assessment of the adherent growth on a polystyrene surface. The methodology included: PCR amplification, whole-genome sequencing (WGS) and crystal violet microtiter plate assay for biofilm quantification. The overall incidence of BAG was: spgM 98.6%, rmlA 86%, and rpfF 66.5%. The most prevalent genotype was spgM+/rmlA+/rpfF+ (56.1%), followed by spgM+/rmlA+/rpfF- (28.5%), and spgM+/rmlA-/rpfF+ (9.5%), with their significant predominance in lower respiratory tract isolates compared to those with other origin (P < 0.001). All strains examined were characterized as strong biofilm producers (OD550 from 0.224 ± 0.049 to 2.065 ± 0.023) with a single exception that showed a weak biofilm-forming ability (0.177 ± 0.024). No significant differences were observed in the biofilm formation according to the isolation source, as well as among COVID-19 and non-COVID-19 isolates (1.256 ± 0.028 vs. 1.348 ± 0.128, respectively). Also, no correlation was found between the biofilm amounts and the corresponding genotypes. WGS showed that the rmlA accumulated a larger number of variants (0.0086 per base) compared to the other BAG, suggesting no critical role of its product to the biofilm formation. Additionally, two of the isolates were found to harbour class 1 integrons (7-kb and 2.6-kb sized, respectively) containing sul1 in their 3' conservative ends, which confers sulfonamide resistance. To the best of our knowledge, this is the first study on S. maltophilia biofilm formation in Bulgaria, which also identifies novel sequence types (ST819, ST820 and ST826). It demonstrates the complex nature of this adaptive mechanism in the multifactorial pathogenesis of biofilm-associated infections.}, }
@article {pmid36639965, year = {2023}, author = {Oliver, C and Céspedes, C and Santibañez, N and Ruiz, P and Romero, A}, title = {Subinhibitory concentrations of florfenicol increase the biofilm formation of Piscirickettsia salmonis.}, journal = {Journal of fish diseases}, volume = {}, number = {}, pages = {}, doi = {10.1111/jfd.13757}, pmid = {36639965}, issn = {1365-2761}, abstract = {Public health is facing a new challenge due to the increased bacterial resistance to most of the conventional antibacterial agents. Inadequate use of antibiotics in the Chilean aquaculture industry leads to the generation of multidrug resistance bacteria. Many fish pathogenic bacteria produce biofilm upon various sources of stress such as antibiotics, which provides several survival advantages for the bacterial life in community and can constitute a reservoir of pathogens in the marine environment. Being florfenicol a broad-spectrum antibiotic commonly used to treat infections in aquaculture, the aim of this study was to assess whether this antibiotic modulates in vitro the biofilm formation in several isolates of Piscirickettsia salmonis. Standard antibiotic-micro broth 96-flat well plates were used to determinate the minimal inhibitory concentration of florfenicol in eight different P. salmonis isolates. In vitro findings, with P. salmonis growing in the presence and absence of the antibiotic, exhibited a statistically significantly increase (p < .05) in biofilm formation in all the bacterial isolates cultivated with sub-MIC (defined as the half of the minimal inhibitory concentration in the presence of antibiotic) of florfenicol compared with controls (antibiotic-free broth). In conclusion, sub-MIC of florfenicol induced an increased biofilm formation in all P. salmonis isolates tested.}, }
@article {pmid36639539, year = {2023}, author = {Wang, L and Wang, H and Zhang, H and Wu, H}, title = {Formation of a biofilm matrix network shapes polymicrobial interactions.}, journal = {The ISME journal}, volume = {}, number = {}, pages = {}, pmid = {36639539}, issn = {1751-7370}, abstract = {Staphylococcus aureus colonizes the same ecological niche as many commensals. However, little is known about how such commensals modulate staphylococcal fitness and persistence. Here we report a new mechanism that mediates dynamic interactions between a commensal streptococcus and S. aureus. Commensal Streptococcus parasanguinis significantly increased the staphylococcal biofilm formation in vitro and enhanced its colonization in vivo. A streptococcal biofilm-associated protein BapA1, not fimbriae-associated protein Fap1, is essential for dual-species biofilm formation. On the other side, three staphylococcal virulence determinants responsible for the BapA1-dependent dual-species biofilm formation were identified by screening a staphylococcal transposon mutant library. The corresponding staphylococcal mutants lacked binding to recombinant BapA1 (rBapA1) due to lower amounts of eDNA in their culture supernatants and were defective in biofilm formation with streptococcus. The rBapA1 selectively colocalized with eDNA within the dual-species biofilm and bound to eDNA in vitro, highlighting the contributions of the biofilm matrix formed between streptococcal BapA1 and staphylococcal eDNA to dual-species biofilm formation. These findings have revealed an additional new mechanism through which an interspecies biofilm matrix network mediates polymicrobial interactions.}, }
@article {pmid36638844, year = {2023}, author = {Sousa, A and Phung, AN and Škalko-Basnet, N and Obuobi, S}, title = {Smart delivery systems for microbial biofilm therapy: Dissecting design, drug release and toxicological features.}, journal = {Journal of controlled release : official journal of the Controlled Release Society}, volume = {}, number = {}, pages = {}, doi = {10.1016/j.jconrel.2023.01.003}, pmid = {36638844}, issn = {1873-4995}, abstract = {Bacterial biofilms are highly protected surface attached communities of bacteria that typically cause chronic infections. To address their recalcitrance to antibiotics and minimise side effects of current therapies, smart drug carriers are being explored as promising platforms for antimicrobials. Herein, we briefly summarize recent efforts and considerations that have been applied in the design of these smart carriers. We guide readers on a journey on how they can leverage the inherent biofilm microenvironment, external stimuli, or combine both types of stimuli in a predictable manner. The specific carrier features that are responsible for their 'on-demand' properties are detailed and their impact on antibiofilm property are further discussed. Moreover, an analysis on the impact of such features on drug release profiles is provided. Since nanotechnology represents a significant slice of the drug delivery cake, some insights on the potential toxicity are also depicted. We hope that this review inspires researchers to use their knowledge and creativity to design responsive systems that can eradicate biofilm infections.}, }
@article {pmid36638675, year = {2023}, author = {Feng, K and Lou, Y and Li, Y and Lu, B and Fang, A and Xie, G and Chen, C and Xing, D}, title = {Conductive carrier promotes synchronous biofilm formation and granulation of anammox bacteria.}, journal = {Journal of hazardous materials}, volume = {447}, number = {}, pages = {130754}, doi = {10.1016/j.jhazmat.2023.130754}, pmid = {36638675}, issn = {1873-3336}, abstract = {The extracellular electron transfer capability of some anaerobic ammonium oxidation (anammox) bacteria was confirmed in recent years. However, the effect of conductive carriers on the synchronous formation of anammox biofilm and granules is rarely reported. Anammox biofilm and granules with compact and stable structures accelerate the initiation and enhance the stability of the anammox process. In this study, we found that the conductive carbon fiber brush (CB) carrier promoted synchronous biofilm formation and granulation of anammox bacteria in the internal circulation immobilized blanket (ICIB) reactor. Compared with polyurethane sponge and zeolite carrier, the ICIB reactor packed with CB carrier can be operated under the highest total nitrogen loading rate of 6.53 kg-N/(m[3]·d) and maintain the effluents NH4[+]-N and NO2[-]-N at less than 1 mM. The volatile suspended solids concentration in the ICIB reactor packed with conductive carrier increased from 5.17 ± 0.40 g/L of inoculum sludge to 24.24 ± 1.20 g/L of biofilm, and the average particle size of granules increased from 222.09 µm to 879.80 µm in 150 days. Fluorescence in situ hybridization analysis showed that anammox bacteria prevailed in the biofilm and granules. The analysis of extracellular polymeric substances indicated that protein and humic acid-like substances played an important role in the formation of anammox biofilm and granules. Microbiome analysis showed that the relative abundance of Candidatus Jettenia was increased from 0.18% to 38.15% in the biofilm from CB carrier during start-up stage. This study provides a strategy for rapid anammox biofilm and granules enrichment and carrier selection of anammox process.}, }
@article {pmid36638563, year = {2023}, author = {Cui, W and Hale, RC and Huang, Y and Zhou, F and Wu, Y and Liang, X and Liu, Y and Tan, H and Chen, D}, title = {Sorption of representative organic contaminants on microplastics: Effects of chemical physicochemical properties, particle size, and biofilm presence.}, journal = {Ecotoxicology and environmental safety}, volume = {251}, number = {}, pages = {114533}, doi = {10.1016/j.ecoenv.2023.114533}, pmid = {36638563}, issn = {1090-2414}, abstract = {Microplastic pollution has attracted mounting concerns worldwide. Microplastics may concentrate organic and metallic contaminants; thus, affecting their transport, fate and organismal exposure. To better understand organic contaminant-microplastic interactions, our study explored the sorption of selected polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), α-hexabromocyclododecane (α-HBCDD), and organophosphate flame retardants (OPFRs) on high-density polyethylene (HDPE) and polyvinylchloride (PVC) microplastics under saline conditions. Sorption isotherms determined varied between chemicals and between HDPE and PVC microplastics. Log Freundlich sorption coefficients (Log KF) for the targeted chemicals ranged from 2.01 to 5.27 L kg[-1] for HDPE, but were significantly lower for PVC, i.e., ranging from Log KF data (2.84 - 8.58 L kg[-1]). Significant correlations between chemicals' Log KF and Log Kow (octanol-water partition coefficient) indicate that chemical-dependent sorption was largely influenced by their hydrophobicity. Sorption was evaluated using three size classes (< 53, 53 - 300, and 300 - 1000 µm) of lab-fragmented microplastics. Particle size did not significantly affect sorption isotherms, but influenced the time to reach equilibrium and the predicted maximum sorption, likely related to microplastic surface areas. The presence of biofilms on HDPE particles significantly enhanced contaminant sorption capacity, indicating more complex sorption dynamics in the chemical-biofilm-microplastic system. Our findings offer new insights into the chemical-microplastic interactions in marine environment.}, }
@article {pmid36637413, year = {2023}, author = {Miao, L and Li, C and Adyel, TM and Huang, W and Wu, J and Yu, Y and Hou, J}, title = {Effects of the Desiccation Duration on the Dynamic Responses of Biofilm Metabolic Activities to Rewetting.}, journal = {Environmental science &amp; technology}, volume = {}, number = {}, pages = {}, doi = {10.1021/acs.est.2c07410}, pmid = {36637413}, issn = {1520-5851}, abstract = {Global climate changes have increased the duration and frequency of river flow interruption, affecting the physical and community structure of benthic biofilms. However, the dynamic responses of biofilm metabolism during the dry-wet transition remain poorly understood. Herein, the dynamic changes in biofilm metabolic activities were investigated through mesocosm experiments under short-term (25 day) and long-term drought (90 day), followed by a 20 day rewetting. The biofilm ecosystem metabolism, as measured by gross primary production and community respiration, was significantly inhibited and turned heterotrophic during the desiccation phase and then recovered, becoming autotrophic during the rewetting period regardless of the desiccation periods due to the high resilience of the autotrophic community. However, long-term drought decreased the recovery rate of the ecosystem metabolism and also caused irreparable damage to the biofilm carbon metabolism, measured using Biolog Eco Plates. Specifically, the recovery of the total carbon metabolic activity is related to the specific carbon source utilized by biofilm microorganisms, such as polymers, carbohydrates, and carboxylic acids. However, the divergent changes of amino acids caused the failure of the total carbon metabolism in long-term drought treatments to recover to the control level even after 20 days of rewetting. This research provides direct evidence that the increased duration of non-flow periods affects biofilm-mediated carbon biogeochemical processes.}, }
@article {pmid36636842, year = {2023}, author = {Öcalan, F and Mumcuoğlu, &#x130; and Ünaldı, &#xd6; and Bakkaloğlu, Z and Dinç, B}, title = {[Evaluation of Antibiotic Susceptibility, Biofilm Production and Clonal Analysis of Corynebacterium striatum Isolates].}, journal = {Mikrobiyoloji bulteni}, volume = {57}, number = {1}, pages = {1-13}, doi = {10.5578/mb.20239901}, pmid = {36636842}, issn = {0374-9096}, abstract = {In this study, it was aimed to determine the possible factors affecting the clinical importance of Corynebacterium striatum isolates, which were accepted as infectious or contamination/colonization agents, by comparing their clinical and microbiological characteristics, antimicrobial susceptibility results, biofilm forming abilities and genotypic characteristics. The patients with C.striatum growth in the clinical samples sent to the laboratory were evaluated as infection or contamination/colonization with the evaluation of the examination findings and other laboratory parameters by the relevant physician. This study included 58 isolates, 29 of which were considered as infection and 29 as contamination/colonization. Length of hospital stay, presence of underlying disease [diabetes mellitus (DM), neurological disease, ischemic heart disease, chronic kidney disease, solid tumor], surgical operation status in the last month, and antibiotic use in the last three months of the patients were examined. Identification of the bacterial type was made with MALDI-TOF MS (Bruker/Germany) system. Antimicrobial susceptibility tests were performed by disc diffusion and gradient diffusion method and evaluated according to EUCAST standards. Biofilm production was determined in 96-well microtiter plates on negatively charged polystyrene surfaces. Clonal analyzes were performed by PFGE method using Xba1 enzyme. It was observed that there was no difference in terms of demographic characteristics in the two patient groups included in the study. It was observed that C.striatum strains isolated from outpatients were mostly found in the contamination/ colonization group. The presence of diabetes mellitus, ischemic heart disease, chronic kidney disease and solid tumor was not statistically different in the two patient groups. It was observed that C.striatum strains grown in the samples of patients with neurological disease were mostly found in the infectious agent group (p= 0.025). It has been observed that C.striatum strains grown purely in culture were mostly found in the infectious agent group (p= 0.001). Biofilm production was found to be significantly higher in the infectious agent group (p= 0.015). In antimicrobial susceptibility tests, it was observed that there was widespread multidrug resistance (MDR) in both groups and there was no significant difference between the groups in terms of antimicrobial susceptibility. In our study, it was determined that the strains showed very different PFGE patterns and were not clonally related to each other. In this study, it was determined that the demographic characteristics and comorbidities of the patients were not helpful in evaluating the clinical significance of C.striatum. Biofilm production was observed to be a common virulence factor in C.striatum strains. It was thought that there may be difficulties in the treatment of C.striatum in the future due to the widespread MDR detection among this bacterium strains. Our study contributes to draw attention to the increase in C.striatum infections, resistance and virulence factors.}, }
@article {pmid36636617, year = {2023}, author = {Mitra, A and Mukhopadhyay, S}, title = {Regulation of biofilm formation by non-coding RNA in prokaryotes.}, journal = {Current research in pharmacology and drug discovery}, volume = {4}, number = {}, pages = {100151}, pmid = {36636617}, issn = {2590-2571}, abstract = {Biofilm refers to microbes that associate with each other or to a surface via self-synthesized exopolysaccharides and other surface-related structures. The presence of biofilms consisting of pathogenic microbes in the food and clinical environment can pose a threat to human health as microbes in biofilms are highly robust and are difficult to remove. Understanding the process of biofilm formation is crucial for the development of novel strategies to control or harness biofilm. The complex network of proteins, small RNA, and diverse molecules regulate biofilm formation at different steps in biofilm development, including triggering the switch from planktonic to sessile cells, maturation of biofilms, and eventual dispersion of microbes from the biofilms. Small non-coding RNAs are relatively small RNAs that are not translated into proteins and play diverse roles in metabolism, physiology, pathogenesis, and biofilm formation. In this review, we primarily focused on non-coding regulatory RNA that regulates biofilm formation in clinically relevant pathogens or threatens human health. Even though many ncRNA have recently been identified in Archaea, much characterization work remains. The mechanisms and regulatory processes controlled by ncRNA in prokaryotes are covered in this review.}, }
@article {pmid36636380, year = {2023}, author = {Mohamad, F and Alzahrani, RR and Alsaadi, A and Alrfaei, BM and Yassin, AEB and Alkhulaifi, MM and Halwani, M}, title = {An Explorative Review on Advanced Approaches to Overcome Bacterial Resistance by Curbing Bacterial Biofilm Formation.}, journal = {Infection and drug resistance}, volume = {16}, number = {}, pages = {19-49}, pmid = {36636380}, issn = {1178-6973}, abstract = {The continuous emergence of multidrug-resistant pathogens evoked the development of innovative approaches targeting virulence factors unique to their pathogenic cascade. These approaches aimed to explore anti-virulence or anti-infective therapies. There are evident concerns regarding the bacterial ability to create a superstructure, the biofilm. Biofilm formation is a crucial virulence factor causing difficult-to-treat, localized, and systemic infections. The microenvironments of bacterial biofilm reduce the efficacy of antibiotics and evade the host's immunity. Producing a biofilm is not limited to a specific group of bacteria; however, Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus biofilms are exemplary models. This review discusses biofilm formation as a virulence factor and the link to antimicrobial resistance. In addition, it explores insights into innovative multi-targeted approaches and their physiological mechanisms to combat biofilms, including natural compounds, phages, antimicrobial photodynamic therapy (aPDT), CRISPR-Cas gene editing, and nano-mediated techniques.}, }
@article {pmid36635396, year = {2023}, author = {Katsipis, G and Pantazaki, AA}, title = {Serrapeptase impairs biofilm, wall, and phospho-homeostasis of resistant and susceptible Staphylococcus aureus.}, journal = {Applied microbiology and biotechnology}, volume = {}, number = {}, pages = {}, pmid = {36635396}, issn = {1432-0614}, abstract = {Staphylococcus aureus biofilms are implicated in hospital infections due to elevated antibiotic and host immune system resistance. Molecular components of cell wall including amyloid proteins, peptidoglycans (PGs), and lipoteichoic acid (LTA) are crucial for biofilm formation and tolerance of methicillin-resistant S. aureus (MRSA). Significance of alkaline phosphatases (ALPs) for biofilm formation has been recorded. Serrapeptase (SPT), a protease of Serratia marcescens, possesses antimicrobial properties similar or superior to those of many antibiotics. In the present study, SPT anti-biofilm activity was demonstrated against S. aureus (ATCC 25923, methicillin-susceptible strain, methicillin-susceptible S. aureus (MSSA)) and MRSA (ST80), with IC50 values of 0.67 μg/mL and 7.70 μg/mL, respectively. SPT affected bacterial viability, causing a maximum inhibition of - 46% and - 27%, respectively. Decreased PGs content at [SPT] ≥ 0.5 μg/mL and ≥ 8 μg/mL was verified for MSSA and MRSA, respectively. In MSSA, LTA levels decreased significantly (up to - 40%) at lower SPT doses but increased at the highest dose of 2 μg/mL, a counter to spectacularly increased cellular and secreted LTA levels in MRSA. SPT also reduced amyloids of both strains. Additionally, intracellular ALP activity decreased in both MSSA and MRSA (up to - 85% and - 89%, respectively), while extracellular activity increased up to + 482% in MSSA and + 267% in MRSA. Altered levels of DING proteins, which are involved in phosphate metabolism, in SPT-treated bacteria, were also demonstrated here, implying impaired phosphorus homeostasis. The differential alterations in the studied molecular aspects underline the differences between MSSA and MRSA and offer new insights in the treatment of resistant bacterial biofilms. KEY POINTS: • SPT inhibits biofilm formation in methicillin-resistant and methicillin-susceptible S. aureus. • SPT treatment decreases bacterial viability, ALP activity, and cell wall composition. • SPT-treated bacteria present altered levels of phosphate-related DING proteins.}, }
@article {pmid36635042, year = {2023}, author = {Andrade, KM and Silva, BPM and de Oliveira, LR and Cury, PR}, title = {Automatic Dental Biofilm Detection Based on Deep Learning.}, journal = {Journal of clinical periodontology}, volume = {}, number = {}, pages = {}, doi = {10.1111/jcpe.13774}, pmid = {36635042}, issn = {1600-051X}, abstract = {AIM: To estimate the automated biofilm detection capacity of the U-Net neural network on tooth images.<br><br>MATERIAL AND METHODS: Two datasets of intraoral photographs taken in the frontal and lateral views of permanent and deciduous dentitions were employed. The first dataset consisted of 96 photographs taken before and after applying a disclosing agent and was used to validate the domain's expert biofilm annotation (intraclass correlation coefficient&#xa0;=&#xa0;0.93). The second dataset comprised 480 photos, with or without orthodontic appliances, without disclosing agents, and was used to train the neural network to segment the biofilm. Dental biofilm labeled by the dentist (without disclosing agents) was considered the ground-truth. Segmentation performance was measured using accuracy, F1 score, sensitivity, and specificity.<br><br>RESULTS: The U-Net model achieved an accuracy of 91.8%, F1 score of 60.6%, specificity of 94.4%, and sensitivity of 67.2%. The accuracy was higher in the presence of orthodontic appliances (92.6%).<br><br>CONCLUSION: Visually segmenting dental biofilm employing a U-Net is feasible and can assist professionals and patients in identifying dental biofilm, thus improving oral hygiene and health. This article is protected by copyright. All rights reserved.}, }
@article {pmid36632686, year = {2023}, author = {Taha, M and Arulanandam, R and Chen, A and Diallo, JS and Abdelbary, H}, title = {Combining povidone-iodine with vancomycin can be beneficial in reducing early biofilm formation of methicillin-resistant Staphylococcus aureus and methicillin-sensitive S. aureus on titanium surface.}, journal = {Journal of biomedical materials research. Part B, Applied biomaterials}, volume = {}, number = {}, pages = {}, doi = {10.1002/jbm.b.35220}, pmid = {36632686}, issn = {1552-4981}, abstract = {There is controversial clinical evidence regarding the added antibacterial benefit of locally administering antiseptic solutions or antibiotics to the infected joint space. The objectives of this in vitro study were to test the efficacy of povidone-iodine (PVP-I) and vancomycin in treating premature and developed Staphylococcus aureus biofilms grown on titanium implant surfaces. PVP-I and vancomycin were used to treat immature and developed biofilms formed by two clinical strains of S. aureus (BP043-MRSA, PB011-MSSA). S. aureus strains were grown as immature (3 h-old) or developed (24 h-old) biofilm. These biofilms were grown on titanium plasma sprayed discs. The treatment regimens tested were: 0.8% PVP-I, 500 μg/ml vancomycin as well as a combination of vancomycin and PVP-I. PVP-I was tested at 3 min, as per current clinical practice, versus 1 min treatment times. In addition, the cytotoxicity of the PVP-I and vancomycin was tested using fresh skeletal muscle tissue cores harvested from the rat's abdominal muscles using alamarBlue assay. The combination of PVP-I (3 min) and vancomycin (24 h.) showed synergistic interaction and the best efficacy against immature biofilms formed by both clinical strains. This degree of eradication was statistically significant compared to the untreated control, p < .0001. However, this combination therapy had limited efficiency against developed biofilms. Also, PVP-I alone was more effective when exposure time was 3 min instead of 1 min against immature biofilm for MRSA, p = .02, and MSSA, p = .01. PVP-I and vancomycin were not effective against developed biofilm regardless of exposure time. Also, combining PVP-I and vancomycin was not cytotoxic to muscle tissue. Combining PVP-I with vancomycin is superior in reducing viable S. aureus cells in immature biofilms grown on titanium surface without causing significant cytotoxicity to muscle tissue. Exposure times and biofilm maturity play a role in dictating the efficacy of using local antiseptics and antibiotics to treat biofilms on implant surfaces.}, }
@article {pmid36631126, year = {2023}, author = {Shiiki, H and Goto, S and Katsuragi, H and Kobayashi, S}, title = {The bactericidal and biofilm removal effect of super reducing water on Streptococcus mutans in three types of orthodontic brackets.}, journal = {Journal of oral science}, volume = {65}, number = {1}, pages = {48-52}, doi = {10.2334/josnusd.22-0320}, pmid = {36631126}, issn = {1880-4926}, abstract = {PURPOSE: To investigate the bactericidal and biofilm removal effect of super reducing water (SRW) on Streptococcus mutans (S. mutans) adhered to orthodontic brackets, in vitro.<br><br>METHODS: Three types of brackets were bonded to aluminum disks. After the formation of S. mutans biofilms on the surfaces, the brackets were divided into three groups (n = 44 each) based on their exposure to SRW: group 1, no treatment; group 2, treated for 5 min; and group 3, treated for 10 min. Total viable counts, adenosine triphosphate measurements, crystal violet assay, and scanning electron microscopy were used to evaluate the effect of SRW.<br><br>RESULTS: The bacterial counts in groups 2 and 3 were significantly lower than those in group 1 (P < 0.001); however, no significant differences were observed between groups 2 and 3. Marked decreases in the number of bacterial colonies and extent of biofilm formation were observed in groups 2 and 3 compared to group 1. No significant differences in the number of bacterial colonies and amount of biofilm were observed among the three types of brackets in each group.<br><br>CONCLUSION: These findings indicate the bactericidal and biofilm removal effect of SRW treatment on S. mutans adhered to orthodontic brackets.}, }
@article {pmid36630113, year = {2023}, author = {Murphy, CA and Bowler, PG and Chowdhury, MF}, title = {'Granulitis': defining a common, biofilm-induced, hyperinflammatory wound pathology.}, journal = {Journal of wound care}, volume = {32}, number = {1}, pages = {22-28}, doi = {10.12968/jowc.2023.32.1.22}, pmid = {36630113}, issn = {0969-0700}, abstract = {The hard-to-heal (chronic) wound condition, now believed to be inextricably linked to the presence of microbial biofilm, has posed challenges in translating scientific understanding to clinical practice in recent decades. During this time, multiple descriptive terms of the wound pathology have been described, including critical colonisation, biofilm infection and inflammatory stasis. However, the absence of naming this disease state as a specifically identified condition that is tangible to treat has led to some confusion and delay in possible therapeutic approaches. When there is clinical uncertainty of wound status, antibiotics are too often inappropriately administered as a precaution. We therefore propose that introducing the term 'granulitis' (inflamed, unhealthy granulation tissue) could be used to identify the biofilm-induced, persistent inflammatory wound condition. This will help to raise clinician and public awareness of the condition, guide appropriate and prompt local wound hygiene, and encourage allocation of adequate resources to improve wound healing outcomes globally.}, }
@article {pmid36629151, year = {2023}, author = {Raile, PN and Oliveira, VC and Macedo, AP and Curylofo, PA and Marcato, PD and Watanabe, E and Paranhos, HFO and Pagnano, VO}, title = {Action of chitosan-based solutions against a model four-species biofilm formed on cobalt-chromium and acrylic resin surfaces.}, journal = {Gerodontology}, volume = {}, number = {}, pages = {}, doi = {10.1111/ger.12672}, pmid = {36629151}, issn = {1741-2358}, abstract = {OBJECTIVE: To evaluate the anti-biofilm action of chitosan, nanoparticulate chitosan, and denture cleanser Nitradine™ against biofilms comprising Candida albicans, Candida glabrata, Staphylococcus aureus, and Streptococcus mutans.<br><br>BACKGROUND: Biofilm removal from removable partial dentures (RPD) is important for success in prosthetic rehabilitation.<br><br>MATERIALS AND METHODS: The anti-biofilm action of the experimental chitosan-based solutions and Nitradine&#x2122; was evaluated on acrylic resin and cobalt-chromium alloy through assessing cell viability, cell metabolism, residual aggregated biofilm, and extracellular polymeric substance and biofilm morphology.<br><br>RESULTS: Only chitosan reduced the viability of C. albicans on cobalt-chromium alloy surface, by 98% (a 1.7 log10 reduction in cfu). Chitosan-based solutions neither promoted substantial alteration of the metabolic activity of the four-species biofilm nor reduced the amount of the aggregated biofilm. After immersion in chitosan and nanoparticulate chitosan, viable microorganisms and extracellular polymeric substances distributed over the entire specimens' surfaces were observed. Nitradine&#x2122; reduced the viability and metabolic activity of biofilm grown on both surfaces, but it did not remove all aggregated biofilm and extracellular polymeric substances. After immersion in Nitradine&#x2122;, approximately 35% of the specimens' surfaces remained covered by aggregated biofilm, mainly composed of dead cells.<br><br>CONCLUSION: Although chitosan and Nitradine&#x2122; promoted changes in the viability of microorganisms, neither solution completely removed the four-species biofilm from the Co-Cr and acrylic resin surfaces. Thus, isolated use of hygiene solutions is not indicated for biofilm control on RPDs; this requires complementary mechanical removal.}, }
@article {pmid36626577, year = {2023}, author = {Jia, T and Wu, P and Liu, B and Liu, M and Mu, H and Liu, D and Huang, M and Li, L and Wei, Y and Wang, L and Yang, Q and Liu, Y and Yang, B and Huang, D and Yang, L and Liu, B}, title = {The phosphate-induced small RNA EsrL promotes E. coli virulence, biofilm formation, and intestinal colonization.}, journal = {Science signaling}, volume = {16}, number = {767}, pages = {eabm0488}, doi = {10.1126/scisignal.abm0488}, pmid = {36626577}, issn = {1937-9145}, abstract = {Escherichia coli are part of the normal intestinal microbiome, but some enterohemorrhagic E. coli (EHEC) and enteropathogenic E. coli (EPEC) strains can cause potentially life-threatening gastroenteritis. Virulence factors underlying the ability of EHEC and EPEC to cause disease include those encoded in the locus of the enterocyte effacement (LEE) pathogenicity island. Here, we demonstrated that EsrL, a small RNA present in many E. coli strains, promoted pathogenicity, adhesion, and biofilm formation in EHEC and EPEC. PhoB, the response regulator of the two-component system that controls cellular responses to phosphate, directly repressed esrL expression under low-phosphate conditions. A phosphate-rich environment, similar to that of the human intestine, relieved PhoB-mediated repression of esrL. EsrL interacted with and stabilized the LEE-encoded regulator (ler) transcript, which encodes a transcription factor for LEE genes, leading to increased bacterial adhesion to cultured cells and colonization of the rabbit colon. EsrL also bound to and stabilized the fimC transcript, which encodes a chaperone that is required for the assembly of type 1 pili, resulting in enhanced cell adhesion in pathogenic E. coli and enhanced biofilm formation in pathogenic and nonpathogenic E. coli. Our findings demonstrate that EsrL stimulates the expression of virulence genes in both EHEC and EPEC under phosphate-rich conditions, thus promoting the pathogenicity of EHEC and EPEC in the nutrient-rich gut environment.}, }
@article {pmid36626427, year = {2022}, author = {Huang, Y and Qin, F and Li, S and Yin, J and Hu, L and Zheng, S and He, L and Xia, H and Liu, J and Hu, W}, title = {The mechanisms of biofilm antibiotic resistance in chronic rhinosinusitis: A review.}, journal = {Medicine}, volume = {101}, number = {49}, pages = {e32168}, doi = {10.1097/MD.0000000000032168}, pmid = {36626427}, issn = {1536-5964}, abstract = {Chronic rhinosinusitis (CRS) is a common but burdensome ailment that is still poorly understood in terms of its pathogenesis. The existence of biofilms on the sinonasal mucosa of individuals with CRS has been proven by current biofilm identification methods. Current treatments for CRS generally include functional endoscopic sinus surgery, biofilm-removing strategies, and limited therapies that target quorum sensing (QS), patients with CRS are often resistant to antimicrobial therapy at degrees achievable by oral or intravenous administration, and even a subset of patients fail to react to either medical or surgical intervention. Multidrug-resistant Pseudomonas aeruginosa, Staphylococcus aureus, especially methicillin-resistant S. aureus, Streptococcus pneumoniae, and Haemophilus influenzae are the most commonly implicated bacteria in CRS patients, which may lead to the persistence and severity of CRS and antibiotic treatment failure via the formation of biofilms. Resistance to antibiotics is attributed to the 3-dimensional structure and QS of biofilms, and the latter describes the communication of bacteria within biofilms. A better understanding of biofilms in CRS and their contribution to the antibiotic resistance of CRS is critical for novel treatment strategies. This review mainly discusses the special structure of biofilms, QS, and their mechanisms of antibiotic resistance in order to investigate prospective anti-biofilm therapies, suggest future directions for study, and potentially refine the CRS prevention paradigm.}, }
@article {pmid36622758, year = {2023}, author = {Pan, Y and Zou, J and Zhang, K and Wang, X and Ma, Q and Mei, L and Li, Y and Pan, Y}, title = {ZccE, a P-type ATPase contributing to biofilm formation and competitiveness in Streptococcus mutans.}, journal = {Molecular oral microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1111/omi.12405}, pmid = {36622758}, issn = {2041-1014}, abstract = {Most living organisms require zinc for survival; however, excessive amounts of this trace element can be toxic. Therefore, the frequent fluctuations of salivary zinc, caused by the low physiological level and the frequent introduction of exogenous zinc ions, present a serious challenge for bacteria colonizing the oral cavity. Streptococcus mutans is considered one of the main bacterial pathobiont in dental caries. Here, we verified the role of a P-type ATPase ZccE as the main zinc-exporting transporter in S. mutans and delineated the effects of zinc toxification caused by zccE deletion in the physiology of this bacterium. The deletion of the gene zccE severely impaired the ability of S. mutans to grow under high zinc stress conditions. Intracellular metal quantification using ICP-OES revealed that the zccE mutant exhibited approximately two times higher zinc accumulation than the wild type when grown in the presence of a subinhibitory zinc concentration. Biofilm formation analysis revealed less single-strain biofilm formation and competitive weakness in the dual-species biofilm formed with Streptococcus sanguinis for zccE mutant under high zinc stress. The qRT-PCR test revealed decreased expressions of gtfB, gtfC, and nlmC in the mutant strain under excessive zinc treatment. Collectively, these findings suggest that ZccE plays an important role in the zinc detoxification of S. mutans and that zinc is a growth-limiting factor for S. mutans within the dental biofilm. This article is protected by copyright. All rights reserved.}, }
@article {pmid36622717, year = {2023}, author = {Moore, R and Spicer, S and Talbert, J and Manning, S and Townsend, S and Gaddy, J}, title = {Anti-Biofilm Activity of Human Milk Oligosaccharides in Clinical Strains of Streptococcus agalactiae with Diverse Capsular and Sequence Types.}, journal = {Chembiochem : a European journal of chemical biology}, volume = {}, number = {}, pages = {}, doi = {10.1002/cbic.202200643}, pmid = {36622717}, issn = {1439-7633}, abstract = {Group B Streptococcus (GBS) is an encapsulated gram-positive bacterial pathogen which causes severe perinatal infections. Human milk oligosaccharides (HMOs) are short-chain sugars that have recently been shown to possess antimicrobial and anti-biofilm activity against a variety of bacterial pathogens, including GBS. We have expanded these studies to demonstrate that HMOs can inhibit and dismantle biofilm in both invasive and colonizing strains of GBS. A cohort of 30 diverse strains of GBS were analyzed for susceptibility to HMO-dependent biofilm inhibition or destruction. HMOs were significantly effective at inhibiting biofilm in capsular type and sequence type specific fashion, with significant efficacy in CpsIb, CpsII, CpsIII, CpsV, and CpsVI strains as well as ST-1, ST-12, ST-19, and ST-23 strains. Interestingly, CpsIa as well as ST-7 and ST-17 were not susceptible to the anti-biofilm activity of HMOs, underscoring the strain-specific effects of these important antimicrobial molecules against the perinatal pathogen, S. agalactiae.}, }
@article {pmid36622472, year = {2023}, author = {Marzhoseyni, Z and Rashki, S and Nazari-Alam, A}, title = {Evaluation of the inhibitory effects of TiO2 nanoparticle and Ganoderma lucidum extract against biofilm-producing bacteria isolated from clinical samples.}, journal = {Archives of microbiology}, volume = {205}, number = {2}, pages = {59}, pmid = {36622472}, issn = {1432-072X}, abstract = {The emergence of multidrug-resistant pathogens leads to treatment failure. So, the need for new antibacterial drugs is urgent. We evaluated the antibacterial and antibiofilm effects of titanium dioxide (TiO2) nanoparticles (NPs) and Ganoderma extract against biofilm-producing Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) by microbroth dilution and crystal violet assays. The combined effect of these compounds was studied using the checkerboard method. The OD260 was measured to assess the destruction of the membrane permeability. The expression of biofilm-related genes (iacA and algD) was investigated by real-time PCR. MRSA isolate was more susceptible to test compounds. The OD260 increased and algD gene was down-regulated after treatment with TiO2 NPs and a combination of TiO2 NPs and Ganoderma extract. iacA gene did not affect by test compounds. Overall, these findings revealed that nanoparticles and natural substances might represent the potential candidates to develop promising antibacterial agents, especially against Gram-positive bacteria.}, }
@article {pmid36622157, year = {2023}, author = {Yang, J and Yun, S and Park, W}, title = {Blue Light Sensing BlsA-Mediated Modulation of Meropenem Resistance and Biofilm Formation in Acinetobacter baumannii.}, journal = {mSystems}, volume = {}, number = {}, pages = {e0089722}, doi = {10.1128/msystems.00897-22}, pmid = {36622157}, issn = {2379-5077}, abstract = {The presence or absence of BlsA, a protein with a blue light-sensing flavin domain in the genomes of Acinetobacter species has aroused curiosity about its roles in the regulation of bacterial lifestyle under light. Genomic and transcriptomic analyses revealed the loss of BlsA in several multidrug-resistant (MDR) A. baumannii strains as well as the light-mediated induction of blsA, along with a possible BlsA-interacting partner BipA. Their direct in vivo interactions were verified using a bacterial two-hybrid system. The results demonstrated that the C-terminal region of BipA could bind to the C-terminal residues of BlsA under blue light at 23°C but not at 37°C. Genetic manipulations of blsA and bipA revealed that the coexistence of BlsA and BipA was required to induce the light-dependent expression of ompA in A. baumannii ATCC 17978 at 23°C. The same phenomenon occurred in the BlsA-deficient MDR strain in our functional complementation assay; however, the underlying molecular mechanism remains poorly understood. BlsA-modulated amounts of OmpA, the most abundant porin, in the outer membrane affected the membrane integrity and permeability of small molecules. Dark conditions or the deletion of ompA made the membrane more permeable to lipophilic ethidium bromide (EtBr) but not to meropenem. Interestingly, light illumination and low temperature conditions made the cells more sensitive to meropenem; however, this bactericidal effect was not noted in the blsA mutant or in the BlsA-deficient MDR strains. Light-mediated cell death and the reduction of biofilm formation at 23°C were abolished in the blsA mutant strain, suggesting multifaceted roles of BlsA in A. baumannii strains. IMPORTANCE Little is known about the functional roles of BlsA and its interacting partners in Acinetobacter species. Intriguingly, no BlsA homolog was found in several clinical isolates, suggesting that BlsA was not required inside the host because of the lack of blue light and the warm temperature conditions. As many chromophore-harboring proteins interact with various partners to control light-dependent cellular behaviors, the maintenance of blsA in the genomes of many Acinetobacter species during their evolution may be beneficial when fluctuations occur in two important environmental factors: light and temperature. Our study is the first to report the novel protein partner of BlsA, namely, BipA, and its contribution to multiple phenotypic changes, including meropenem resistance and biofilm formation. Rapid physiological acclimation to changing light or temperature conditions may be possible in the presence of the light-sensing BlsA protein, which may have more interacting partners than expected.}, }
@article {pmid36621329, year = {2023}, author = {Shamkani, F and Barzi, SM and Badmasti, F and Chiani, M and Mirabzadeh, E and Zafari, M and Shafiei, M}, title = {Enhanced anti-biofilm activity of the minocycline-and-gallium-nitrate using niosome wrapping against Acinetobacter baumannii in C57/BL6 mouse pneumonia model.}, journal = {International immunopharmacology}, volume = {115}, number = {}, pages = {109551}, doi = {10.1016/j.intimp.2022.109551}, pmid = {36621329}, issn = {1878-1705}, abstract = {Acinetobacter baumannii is a worldwide health issue in terms of its high antibiotic resistance and ability to form biofilms. Nanoparticles (NPs) with high biocompatibility, high penetrating ability, and low medication dose can successfully treat the antibiotic-resistant infections. In this research, the anti-biofilm activity of niosomes containing minocycline and gallium nitrate (GaN) against A. baumannii biofilm was determined. In order to improve their anti-biofilm properties, minocycline and GaN were encapsulated in niosomes as biocompatible drug carriers. The niosomes' size, zeta potential, shape, stability, drug entrapment efficacy, drug release pattern and antibacterial activity were assessed. Several clinical samples were isolated from the lungs of patients hospitalized at Loghman hospital, Tehran, Iran. The biofilm formation of most lethal clinical isolates of A. baumannii was analyzed. The pneumonia model was generated by intranasally administering A. baumannii suspension to anesthetized mice whose immune systems was compromised twice by cyclophosphamide. Lung infection of the mouse with A. baumannii was confirmed using PCR. After treatment, the lungs were excised under sterile conditions and stained with hematoxylin and eosin (H&amp;E) to determine histological symptoms, inflammation and intercellular secretions. The niosomes contained minocycline and GaN had an average size of 230 nm and a zeta potential of -40 mV, respectively. The percentage of drug entrapment and delayed drug release was both high in niosomal formulations. Niosomes containing minocycline and GaN dispersed 1, 3 and 5 day old biofilms. The mice given the combination of two compounds required less time to be treated than the animals given the single medication (minocycline). The minocycline&amp; GaN-loaded niosomes could be considered as promising candidates to treat the infections caused by A. baumannii biofilm.}, }
@article {pmid36619994, year = {2022}, author = {Ma, X and Wang, X and Ye, S and Liu, J and Yuan, H and Wang, N}, title = {Biofilm and pathogenic factor analysis of Gardnerella vaginalis associated with bacterial vaginosis in Northeast China.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1033040}, pmid = {36619994}, issn = {1664-302X}, abstract = {INTRODUCTION: Gardnerella vaginalis is a major pathogen responsible for bacterial vaginosis (BV). However, the recurrence of infection and the antibiotic resistance of biofilms remain significant challenges for the treatment of BV. In this study, we aimed to analyze the pathogenic factors and drug sensitivity associated with the clinical treatment of BV in Northeast China.<br><br>METHODS: Subgroups were identified by clade-specific polymerase chain reaction (PCR). Biofilm formation was measured by crystal violet staining, confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The inhibition and eradication of biofilm formation were measured by XTT and broth recovery-based methods.<br><br>RESULTS: Of the 24 samples of G. vaginalis, 11 samples and American Type Culture Collection (ATCC) 14018 formed biofilms; the remainder did not. The positive rates of detection for the sialidase A and vly genes in the 24&#x2009;G. vaginalis samples were 100% and 79.2%, respectively. Moreover, 21 samples (87.5%) showed resistance to metronidazole and 16 (66.7%) presented with sensitivity towards clindamycin. The biofilm MIC80 (BMIC80) of metronidazole for ATCC14018 was 16 &#x3bc;g/ml while that of clindamycin was 0.125 &#x3bc;g/ml. The minimum biofilm eradication concentration (MBEC) of metronidazole was >&#x2009;256 &#x3bc;g/ml while that of clindamycin was >&#x2009;2 &#x3bc;g/ml.<br><br>DISCUSSION: Our results revealed that G. vaginalis is more resistant to metronidazole than clindamycin and neither metronidazole nor clindamycin are able to effectively eradicate vaginal biofilms. Thus, the role of antibiotics and biofilms in BV requires further investigation.}, }
@article {pmid36619751, year = {2022}, author = {Morais, MLGDS and Santos, MGC and Costa, CL and Martins, CS and Leitão, RFC and de Melo Pacífico, D and Quesada-Gómez, C and Castelo Branco, D and Ferreira, EO and Brito, GAC}, title = {Comparative biofilm-forming ability between Clostridioides difficile strains isolated in Latin America and the epidemic NAP1/027 strain.}, journal = {Frontiers in cellular and infection microbiology}, volume = {12}, number = {}, pages = {1033698}, pmid = {36619751}, issn = {2235-2988}, abstract = {INTRODUCTION: One of the challenges in treating Clostridioides difficile infection (CDI) is that the bacterium forms biofilms, a critical virulence mechanism known to promote antibiotic resistance and, as a result, consequently, a higher recurrence of the disease. The goal of this study was to compare the ability of three MLST Clade 2 strains to form a biofilm in vitro: ICC-45 (ribotype SLO231/UK[CE]821), a ST41 toxinotype IXb isolated in Brazil; and two epidemic NAP1/027/ST01 strains: NAP1/027/ST01 (LIBA5756), isolated during a 2010 outbreak in Costa Rica and the reference epidemic strain NAP1/027/ST01 (R20291); and ATCC700057, a non-toxigenic strain.<br><br>METHODS: The ability of strains to form biofilm was evaluated using crystal violet staining. In addition, samples were stained with the Film Tracer biofilm matrix (Invitrogen&#xae;) and the biofilm matrix thickness was measured using confocal microscopy. The matrix architecture was determined using Scanning electron microscop. Confocal microscopy was used to detect the presence of toxin A (tcdA) using an anti-Clostridioides difficile TcdA antibody. The expression of virulence genes (tcdA, tcdB, tcdC, cdtB, spo0A, slpA, cwp66 and cwp84) was examined, as well as the effect of antibiotics metronidazole (MTZ) and vancomycin (VAN) on biofilm growth.<br><br>RESULTS: All of the strains tested formed a moderate biofilm with 1.1 <DO570nm>3.5. After 72h, biofilm biomass of the NAP1/027/ST01 epidemic strains (LIBA5756 and R20291) was significantly higher than ICC-45 and ATCC 700057 biofilms, as confirmed by electron and confocal microscopy. At 120h, the LIBA5756 biofilm biomass decreased compared to other strains. The toxigenic strains R20291 or LIBA 5756 had higher expression of genes tcdA, tcdB, tcdC, cdtA, slpA and spo0A than ICC-45, but there were no significant differences in the expression levels of cdtB, cwp66 and cwp84. In epidemic strains, VAN and MTZ inhibited biofilm formation; however, in the ICC-45 strain, MIC concentrations of VAN and MIC and 4MIC of MTZ did not inhibit biofilm formation.<br><br>CONCLUSION: The three MLST Clade 2 isolated from different rybotipes, two of which were isolated from Latin America, are competent biofilm-forming bacteria, indicating their ability to induce C. difficile infection recurrence, making treatment difficult.}, }
@article {pmid36619453, year = {2022}, author = {Rashtchi, P and Tempelaars, M and van der Linden, E and Abee, T and Habibi, M}, title = {Lactobacillus plantarum strains show diversity in biofilm formation under flow conditions.}, journal = {Heliyon}, volume = {8}, number = {12}, pages = {e12602}, pmid = {36619453}, issn = {2405-8440}, abstract = {In many natural and technological applications, microbial biofilms grow under fluid flow. In this project, we investigated the influence of flow on the formation and growth of biofilms produced by gram-positive Lactobacillus plantarum strains WCFS1 and CIP104448. We used an in-house designed device based on a 48-well plate with culture volumes of 0.8 ml, and quantified total biofilm formation under static and flow conditions with flow rates 0.8, 1.6, 3.2 and 4.8 ml/h (with 1, 2, 4 and 6 volume changes per hour) using crystal violet (CV) staining, and determined the number of viable biofilm cells based on plate counts. The amount of total biofilm under flow conditions increased in the CIP 104448 strain, with significantly increased staining at the wall of the wells. However, in the WCFS1 strain, no significant difference in the amount of biofilm formed under flow and static conditions was observed. Plate counts showed that flow caused an increase in the number of viable biofilm cells for both strains. In addition, using enzyme treatment experiments, we found that for WCFS1 in the static condition, the amount of mature biofilm was declined after DNase I and Proteinase K treatment, while for flow conditions, the decline was only observed for DNase I treatment. The CIP104448 biofilms formed under both static and flow conditions only showed a decline in the CV staining after adding Proteinase K, indicating different contributions of extracellular DNA (eDNA) and proteinaceous matrix components to biofilm formation in the tested strains.}, }
@article {pmid36618067, year = {2023}, author = {Zhang, Y and Yu, H and Xie, Y and Guo, Y and Cheng, Y and Yao, W}, title = {Inhibitory effects of hexanal on acylated homoserine lactones (AHLs) production to disrupt biofilm formation and enzymes activity in Erwinia carotovora and Pseudomonas fluorescens.}, journal = {Journal of food science and technology}, volume = {60}, number = {1}, pages = {372-381}, pmid = {36618067}, issn = {0022-1155}, abstract = {UNLABELLED: Erwinia carotovora and Pseudomonas fluorescens were two bacteria commonly caused the spoilage of vegetables through biofilm formation and secretion of extracellular enzymes. In this study, N-(3-oxohexanoyl)-L-homoserine lactone (3-oxo-C6-HSL) and N-Octanoyl-L-homoserine lactone (C8-HSL) were confirmed as acylated homoserine lactones (AHLs) signal molecule produced by E. carotovora and P. fluorescens, respectively. In addition, quorum sensing inhibitory (QSI) effects of hexanal on AHLs production were evaluated. Hexanal at 1/2 minimum inhibitory concentration (MIC) was achieved 76.27% inhibitory rate of 3-oxo-C6-HSL production in E. carotovora and a inhibitory rate of C8-HSL (60.78%) in P. fluorescens. The amount of biofilm formation and activity of extracellular enzymes treated with 1/2 MIC of hexanal were restored with different concentrations (10 ng/mL, 50 ng/mL, 100 ng/mL) of exogenous AHLs (P < 0.05), which verified QSI effect of hexanal on biofilm and extracellular enzymes were due to its inhibition on AHLs production. Molecular docking analysis showed that hexanal could interact with EcbI and PcoI protein to disrupt AHLs production. Furthermore, results showed that sub-MICs of hexanal could suppress expressions of ecbI and pcoI genes in AHL-mediated QS system of E. carotovora and P. fluorescens. This study provides theoretical support for the application of essential oils as QS inhibitors in the preservation of vegetables.<br><br>SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13197-022-05624-9.}, }
@article {pmid36616511, year = {2022}, author = {Choi, S and Lee, H and Hong, R and Jo, B and Jo, S}, title = {Application of Multi-Layered Temperature-Responsive Polymer Brushes Coating on Titanium Surface to Inhibit Biofilm Associated Infection in Orthopedic Surgery.}, journal = {Polymers}, volume = {15}, number = {1}, pages = {}, doi = {10.3390/polym15010163}, pmid = {36616511}, issn = {2073-4360}, abstract = {Infection associated with biomedical implants remains the main cause of failure, leading to reoperation after orthopedic surgery. Orthopedic infections are characterized by microbial biofilm formation on the implant surface, which makes it challenging to diagnose and treat. One potential method to prevent and treat such complications is to deliver a sufficient dose of antibiotics at the onset of infection. This strategy can be realized by coating the implant with thermoregulatory polymers and triggering the release of antibiotics during the acute phase of infection. We developed a multi-layered temperature-responsive polymer brush (MLTRPB) coating that can release antibiotics once the temperature reaches a lower critical solution temperature (LCST). The coating system was developed using copolymers composed of diethylene glycol methyl ether methacrylate and 2-hydroxyethyl methacrylate by alternatively fabricating monomers layer by layer on the titanium surface. LCST was set to the temperature of 38-40 °C, a local temperature that can be reached during infection. The antibiotic elution characteristics were investigated, and the antimicrobial efficacy was tested against S. aureus species (Xen29 ATCC 29 213) using one to four layers of MLTRPB. Both in vitro and in vivo assessments demonstrated preventive effects when more than four layers of the coating were applied, ensuring promising antibacterial effects of the MLTRPB coating.}, }
@article {pmid36614237, year = {2023}, author = {Maliszewska, I and Zdubek, A}, title = {On the Photo-Eradication of Methicillin-Resistant Staphylococcus aureus Biofilm Using Methylene Blue.}, journal = {International journal of molecular sciences}, volume = {24}, number = {1}, pages = {}, doi = {10.3390/ijms24010791}, pmid = {36614237}, issn = {1422-0067}, abstract = {This work compared the effectiveness of several Methylene Blue (MB)-based protocols for photo-eradication of biofilms formed on the surface of the glass and stainless steel discs by S. aureus MRSA isolates using a diode laser (λ = 665 nm; output power 40 mW; energy fluence was 189 J cm[-2]). The results obtained showed that MB alone, up to a concentration of 62.5 mgL[-1], had limited photo-bactericidal activity. It was possible to enhance the activity of MB using two types of spherical gold nanoparticles of similar sizes, 15 ± 3 nm/20 ± 3 nm, but differing in the method of their synthesis and stabilization. The enhancement of the photodestruction effect was related to the increased production of hydroxyl radicals by the MB+gold nanoparticles mixture, and this mixture showed dark cytotoxicity against the cocci studied. Effective destruction (mortality above 99.9%) of the biofilms formed by MRSA isolates was also possible without the use of gold nanoparticles, but the concentration of MB had to be at least 125 mgL[-1]. A highly efficient protocol of photodestruction of biofilms, consisting of triple exposure of biofilms to laser light in the presence of MB alone, combined with the removal of dead bacteria protecting deep layers of pathogens against photosensitization, was also described.}, }
@article {pmid36614040, year = {2022}, author = {Jean-Pierre, V and Boudet, A and Sorlin, P and Menetrey, Q and Chiron, R and Lavigne, JP and Marchandin, H}, title = {Biofilm Formation by Staphylococcus aureus in the Specific Context of Cystic Fibrosis.}, journal = {International journal of molecular sciences}, volume = {24}, number = {1}, pages = {}, doi = {10.3390/ijms24010597}, pmid = {36614040}, issn = {1422-0067}, abstract = {Staphylococcus aureus is a major human pathogen whose characteristics support its success in various clinical settings including Cystic Fibrosis (CF). In CF, S. aureus is indeed the most commonly identified opportunistic pathogen in children and the overall population. S. aureus colonization/infection, either by methicillin-susceptible or methicillin-resistant strains, will become chronic in about one third of CF patients. The persistence of S. aureus in CF patients' lungs, despite various eradication strategies, is favored by several traits in both host and pathogen. Among the latter, living in biofilm is a highly protective way to survive despite deleterious environmental conditions, and is a common characteristic shared by the main pathogens identified in CF. This is why CF has earned the status of a biofilm-associated disease for several years now. Biofilm formation by S. aureus, and the molecular mechanisms governing and regulating it, have been extensively studied but have received less attention in the specific context of CF lungs. Here, we review the current knowledge on S. aureus biofilm in this very context, i.e., the importance, study methods, molecular data published on mono- and multi-species biofilm and anti-biofilm strategies. This focus on studies including clinical isolates from CF patients shows that they are still under-represented in the literature compared with studies based on reference strains, and underlines the need for such studies. Indeed, CF clinical strains display specific characteristics that may not be extrapolated from results obtained on laboratory strains.}, }
@article {pmid36613809, year = {2022}, author = {Chudzik-Rząd, B and Zalewski, D and Kasela, M and Sawicki, R and Szymańska, J and Bogucka-Kocka, A and Malm, A}, title = {The Landscape of Gene Expression during Hyperfilamentous Biofilm Development in Oral Candida albicans Isolated from a Lung Cancer Patient.}, journal = {International journal of molecular sciences}, volume = {24}, number = {1}, pages = {}, doi = {10.3390/ijms24010368}, pmid = {36613809}, issn = {1422-0067}, abstract = {The filamentation ability of Candida albicans represents one of the main virulence factors allowing for host tissue penetration and biofilm formation. The aim of this paper was to study the genetic background of the hyperfilamentous biofilm development in vitro in C. albicans isolated from the oral cavity of a lung cancer patient. Analyzed C. albicans isolates (CA1, CA2, CA3) were chosen based on their different structures of mature biofilm. The CA3 isolate possessing hyperfilamentation properties and forming high biofilm was compared with CA1 and CA2 isolates exhibiting low or average biofilm-forming ability, respectively. The detailed biofilm organization was studied with the use of confocal scanning laser microscopy. The whole transcriptome analysis was conducted during three stages of biofilm development (24 h, 48 h, 72 h). In contrast to CA1 and/or CA2 isolate, the CA3 isolate was characterized by a significant upregulation of genes encoding for cell wall proteins (HWP1, PGA13, PGA44, ALS3) and candidalysin (ECE1), as well as being involved in iron metabolism (FRE1, ALS3), sulfur metabolism (HAL21), the degradation of aromatic compounds (HQD2), and membrane transport (DIP5, PHO89, TNA1). In contrast, some genes (SCW11, FGR41, RBE1) in the CA3 were downregulated. We also observed the overexpression of a few genes over time-mainly FRE1, ATX1, CSA2 involved in iron metabolism. This is the first insight into the potential function of multiple genes in the hyperfilamentous biofilm formation in C. albicans, primarily isolated from host tissue, which may have an important clinical impact on cancer patients. Moreover, the presented data can lay the foundation for further research on novel pathogen-specific targets for antifungal drugs.}, }
@article {pmid36613306, year = {2022}, author = {Savijoki, K and San-Martin-Galindo, P and Pitkänen, K and Edelmann, M and Sillanpää, A and van der Velde, C and Miettinen, I and Patel, JZ and Yli-Kauhaluoma, J and Parikka, M and Fallarero, A and Varmanen, P}, title = {Food-Grade Bacteria Combat Pathogens by Blocking AHL-Mediated Quorum Sensing and Biofilm Formation.}, journal = {Foods (Basel, Switzerland)}, volume = {12}, number = {1}, pages = {}, doi = {10.3390/foods12010090}, pmid = {36613306}, issn = {2304-8158}, abstract = {Disrupting bacterial quorum sensing (QS) signaling is a promising strategy to combat pathogenic biofilms without the development of antibiotic resistance. Here, we report that food-associated bacteria can interfere with the biofilm formation of a Gram-negative pathogenic bacterium by targeting its AHL (acyl-homoserine lactone) QS system. This was demonstrated by screening metabolic end-products of different lactobacilli and propionibacteria using Gram-negative and biofilm-forming Chromobacterium violaceum as the QS reporter and our anti-QS microscale screening platform with necessary modifications. The method was optimized in terms of the inoculation technique and the concentrations of D-glucose and L-tryptophan, two key factors controlling the synthesis of violacein, a purple pigment indicating the activation of the QS system in C. violaceum. These improvements resulted in ca. 16-times higher violacein yields and enabled revealing anti-QS effects of Lactobacillus acidophilus, Lentilactobacillus kefiri, Lacticaseibacillus rhamnosus and Propionibacterium freudenreichii, including new cheese-associated strains. Our findings also suggest that acetate and propionate excreted by these species are the main factors that interrupt the QS-mediated signaling and subsequent biofilm growth without affecting the cell viability of the C. violaceum reporter. Thus, the present study reports a revised anti-QS screening method to accurately define new bacteria with an ability to combat pathogens in a safe and sustainable way.}, }
@article {pmid36610197, year = {2023}, author = {Zhu, W and Chen, J and Zhang, H and Yuan, S and Guo, W and Zhang, Q and Zhang, S}, title = {Start-up phase optimization of pyrite-intensified hybrid sequencing batch biofilm reactor (PIHSBBR): Mixotrophic denitrification performance and mechanism.}, journal = {Journal of environmental management}, volume = {330}, number = {}, pages = {117232}, doi = {10.1016/j.jenvman.2023.117232}, pmid = {36610197}, issn = {1095-8630}, abstract = {Pyrite-based autotrophic denitrification (PAD) is an emerging biological process to diminish nitrate pollution, but the relatively low NO3[-]-N removal rate limits its practical application. In this research, a pyrite-intensified hybrid sequencing batch biofilm reactor (PIHSBBR) was designed to treat low C/N ratio domestic wastewater. The results showed that PIHSBBR could achieve optimal removal of COD, NH4[+]-N, and TN under the aeration rate of 1.0 L/L∙min and the hydraulic retention time (HRT) of 8 h, with removal rates of 69.67 ± 4.37%, 77.04 ± 4.84%, and 63.92 ± 6.66%, respectively. The PAD efficiency in PIHSBBR during the stable operation was not high (13.05-31.01%), and the main nitrogen removal pathway in PIHSBBR, especially in the aerobic zone, was simultaneous nitrification and denitrification (SND). High-throughput sequencing analysis unraveled that Planctomycetota (3.65%) had a high abundance in the anoxic zone of PIHSBBR, implying that anaerobic ammonium oxidation (anammox) might have occurred in the anoxic zone. In addition, the nitrogen cycle function gene with the highest abundance was nirBD, indicating the possible presence of dissimilatory nitrate reduction to ammonium (DNRA) within the system (aerobic and anoxic zones). Our research can provide useful information for the improvement and future application of PIHSBBR.}, }
@article {pmid36608761, year = {2023}, author = {Wang, WQ and Feng, XC and Shi, HT and Wang, YM and Jiang, CY and Xiao, ZJ and Xu, YJ and Zhang, X and Yuan, Y and Ren, NQ}, title = {Biofilm inhibition based on controlling the transmembrane transport and extracellular accumulation of quorum sensing signals.}, journal = {Environmental research}, volume = {}, number = {}, pages = {115218}, doi = {10.1016/j.envres.2023.115218}, pmid = {36608761}, issn = {1096-0953}, abstract = {The regulation of bacterial quorum sensing (QS) has been used to inhibit biofouling in wastewater treatment plants and the formation of biofilms. In contrast to traditional QS regulation strategies, this study aimed to obstruct the transmembrane transport process of QS signals to decrease their extracellular accumulation. Three phytochemicals, astragaloside IV, eugenol, and baicalin were selected, their effects on biofilm formation by Pseudomonas aeruginosa PA14 were studied, and the mechanisms determined. The inhibition efficiency of biofilm formation by 50 mg/L astragaloside IV, 1 mg/L eugenol, and 1 mg/L baicalin were 37%, 26%, and 26%, respectively. Confocal laser scanning microscopy and analysis of extracellular polymeric substances indicated that the three inhibitors affected the structure and composition of the biofilms. Furthermore, bacterial motility and a variety of QS-related virulence factors were suppressed by the inhibitor treatment due to changes in bacterial QS. Notably, the three inhibitors all decreased the extracellular concentration of the QS signaling molecule 3-oxo-C12-homoseine lactone by affecting the function of efflux pump MexAB-OprM. This indirectly interfered with the bacterial QS system and thus inhibited biofilm formation. In conclusion, this study revealed the inhibitory effects and inhibition mechanism of three phytochemicals on efflux pump and QS of P. aeruginosa and realized the inhibition on biofilm formation. We update the efflux pump inhibitor library and provide a new way for biofilm contamination control.}, }
@article {pmid36608472, year = {2023}, author = {Su, Z and Kong, L and Mei, J and Li, Q and Qian, Z and Ma, Y and Chen, Y and Ju, S and Wang, J and Jia, W and Zhu, C and Fan, W}, title = {Enzymatic bionanocatalysts for combating peri-implant biofilm infections by specific heat-amplified chemodynamic therapy and innate immunomodulation.}, journal = {Drug resistance updates : reviews and commentaries in antimicrobial and anticancer chemotherapy}, volume = {67}, number = {}, pages = {100917}, doi = {10.1016/j.drup.2022.100917}, pmid = {36608472}, issn = {1532-2084}, abstract = {Bacterial biofilm-associated infection is a life-threatening emergency contributing from drug resistance and immune escape. Herein, a novel non-antibiotic strategy based on the synergy of bionanocatalysts-driven heat-amplified chemodynamic therapy (CDT) and innate immunomodulation is proposed for specific biofilm elimination by the smart design of a biofilm microenvironment (BME)-responsive double-layered metal-organic framework (MOF) bionanocatalysts (MACG) composed of MIL-100 and CuBTC. Once reaching the acidic BME, the acidity-triggered degradation of CuBTC allows the sequential release of glucose oxidase (GOx) and an activable photothermal agent, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). GOx converts glucose into H2O2 and gluconic acid, which can further acidify the BME to accelerate the CuBTC degradation and GOx/ABTS release. The in vitro and in vivo results show that horseradish peroxidase (HRP)-mimicking MIL-100 in the presence of self-supplied H2O2 can catalyze the oxidation of ABTS into oxABTS to yield a photothermal effect that breaks the biofilm structure via eDNA damage. Simultaneously, the Cu ion released from the degraded CuBTC can deplete glutathione and catalyze the splitting of H2O2 into •OH, which can effectively penetrate the heat-induced loose biofilms and kill sessile bacteria (up to 98.64%), such as E. coli and MRSA. Particularly, MACG-stimulated M1-macrophage polarization suppresses the biofilm regeneration by secreting pro-inflammatory cytokines (e.g., IL-6, TNF-α, etc.) and forming a continuous pro-inflammatory microenvironment in peri-implant biofilm infection animals for at least 14 days. Such BME-responsive strategy has the promise to precisely eliminate refractory peri-implant biofilm infections with extremely few adverse effects.}, }
@article {pmid36606321, year = {2023}, author = {Soontarach, R and Nwabor, OF and Voravuthikunchai, SP}, title = {Interaction of lytic phage T1245 with antibiotics for enhancement of antibacterial and anti-biofilm efficacy against multidrug-resistant Acinetobacter baumannii.}, journal = {Biofouling}, volume = {}, number = {}, pages = {1-12}, doi = {10.1080/08927014.2022.2163479}, pmid = {36606321}, issn = {1029-2454}, abstract = {Biofilms associated with multidrug-resistant (MDR) Acinetobacter baumannii on medical devices remain a big clinical problem. Antibiotic susceptibility tests were performed with eight commonly employed antibiotics against clinical isolates. The effects of antibiotics in combination with well-characterized lytic phage T1245 were studied to assess their antibacterial and anti-biofilm efficacy. Ceftazidime, colistin, imipenem, and meropenem significantly reduced bacterial density up to approximately 80% when combined with phage T1245, compared with control. Phage T1245 in combination with ceftazidime, colistin, and meropenem at subinhibitory concentrations demonstrated significant reduction in biomass and bacterial viability of 3-day established biofilms, compared with antibiotic alone. In addition, electron microscopy further confirmed the disruption of biofilm structure and cell morphology upon treatment with phage T1245 and antibiotics, including ceftazidime, colistin, and meropenem. Combined treatment of phage T1245 with these antibiotics could be employed for the management of A. baumannii infections and eradication of the bacterial biofilms.}, }
@article {pmid36606087, year = {2023}, author = {Yum, SJ and Jeong, HG and Kim, SM}, title = {Anti-biofilm effects of sinomenine against Staphylococcus aureus.}, journal = {Food science and biotechnology}, volume = {32}, number = {1}, pages = {83-90}, pmid = {36606087}, issn = {2092-6456}, abstract = {Staphylococcus aureus is a gram-positive foodborne pathogen capable of forming strong biofilms. This study identified that anti-biofilm natural compound against S. aureus. Sinomenine, a natural compound, showed significantly reduced biofilm formation (31.97-39.86%), but no effect on bacterial growth was observed. The dispersion of preformed biofilms was observed by confocal laser scanning microscopy (CLSM). qRT-PCR revealed that sinomenine treatment significantly up-regulated agrA by 3.8-fold and down-regulated icaA gene by 3.1-fold. These indicate that sinomenine treatment induces biofilm dispersal due to cell-cell adhesion, polysaccharide intercellular adhesin (PIA), and phenol-soluble modulin (PSM) peptides production. Our results suggest that sinomenine can be used as a promising agent for effectively controlling biofilm formation and dispersion, thereby making S. aureus more susceptible to the action of antimicrobial agents.}, }
@article {pmid36606039, year = {2023}, author = {Gou, H and Cao, Q and Wang, Z and Liu, Y and Sun, Y and Wei, H and Song, C and Tian, C and Wei, Y and Xue, H}, title = {Transcriptomic analysis of Listeria monocytogenes biofilm formation at different times.}, journal = {Canadian journal of veterinary research = Revue canadienne de recherche veterinaire}, volume = {87}, number = {1}, pages = {59-66}, pmid = {36606039}, issn = {1928-9022}, abstract = {Biofilm (BF) formation is a considerable obstacle to the effective control of Listeria monocytogenes (LM). In this study, we used transcriptomics to analyze LM BF and planktonic bacteria at different stages of BF formation and growth to compare differential gene expression between the 2. We identified 1588, 1517, and 1462 differentially expressed genes (DEGs) when early formation BF and planktonic bacteria were compared at 12, 24, and 48 h, respectively. Among these, 1123 DEGs were shared across the 3 data pool. Gene Ontology functional enrichment and Kyoto Encyclopedia of Genes and Genomes pathway analyses demonstrated significant changes associated with the phosphotransferase system, the microbial metabolism in diverse environments, the flagella assembly, the bacterial chemotaxis, the bacterial secretion, the quorum sensing, and the 2-component system. The top 5 upregulated DEGs were lmo0024, lmo0374, lmo0544, hly, and lmo2434. The top 5 downregulated DEGs were lmo2192, lmo1211, cheY, lmo0689, and secY. After real-time quantitative polymerase chain reaction, the expression of these 10 DEGs were consistent with the results of the transcriptomic sequence. This research lays the foundation for further studies on mechanisms regulating BF formation and will help to identify BF inhibitors to reduce the risk of LM infection.}, }
@article {pmid36605406, year = {2023}, author = {Gu, M and Cho, JH and Suh, JW and Cheng, J}, title = {Potential oral probiotic Lactobacillus pentosus MJM60383 inhibits Streptococcus mutans biofilm formation by inhibiting sucrose decomposition.}, journal = {Journal of oral microbiology}, volume = {15}, number = {1}, pages = {2161179}, pmid = {36605406}, issn = {2000-2297}, abstract = {Streptococcus mutans is known as a contributor to dental caries. In this work, Lactobacillus pentosus MJM60383 was selected for its strong antagonistic activity against S. mutans and was characterized by good oral probiotic properties including lysozyme tolerance, adhesive ability to oral cells, good aggregation (auto-aggregation, co-aggregation) ability, hydrogen peroxide production and inhibition of biofilm formation of S. mutans. L. pentosus MJM60383 also exhibited safety as a probiotic characterized by no hemolytic activity, no D-lactate production, no biogenic amine production, and susceptibility to antibiotics. Furthermore, the biofilm formation of S. mutans was also significantly inhibited by the supernatant of L. pentosus MJM60383. An anti-biofilm mechanism study revealed that sucrose decomposition and the production of water-insoluble exopolysaccharides by S. mutans were inhibited by the treatment with L. pentosus MJM60383 supernatant. Real-time PCR analysis indicated that the supernatant of L. pentosus MJM60383 significantly inhibited the mRNA expression of S. mutans glycosyltransferases, which synthesize glucan to construct biofilm architecture and mediate bacterial adherence. Our study demonstrated L. pentosus MJM60383 as a potential oral probiotic and revealed its anti-biofilm mechanism.}, }
@article {pmid36605101, year = {2022}, author = {Jalalifar, S and Mirzaei, R and Motallebirad, T and Razavi, S and Talebi, M}, title = {The Emerging Role of Probiotics and their Derivatives against Biofilm-Producing MRSA: A Scoping Review.}, journal = {BioMed research international}, volume = {2022}, number = {}, pages = {4959487}, pmid = {36605101}, issn = {2314-6141}, abstract = {BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main bacterial pathogens causing chronic infections, mainly because of its capacity to produce biofilm. Biofilm production is one of the underlying strategies for antibacterial drug resistance. Accordingly, preventing and attenuating biofilm production has become an emerging approach to controlling persistent infections. Therefore, this scoping review is aimed at surveying the published literature describing the usage of probiotics and their derivatives against biofilm-producing MRSA.<br><br>METHODS: Updated literature searches were conducted across seven electronic databases including Web of Science, PubMed, Scopus, Cochrane Library, ProQuest, Embase, and Google Scholar to identify all original published articles about probiotics against MRSA. In this regard, studies were summarized and analyzed in the present review.<br><br>RESULTS: In the reviewed studies, various microorganisms and compounds were used as probiotics as follows: Lactobacillus species (8 studies), Enterococcus species (4 studies), Bacillus species (2 studies), Streptomyces species (2 studies), Saccharomyces cerevisiae (1 study), Corynebacterium accolens (1 study), and Lactococcus lactis derived Nisin (3 studies). Based on our comprehensive search, 21 studies with eligibility criteria were included in the present review including 12 studies on clinical strains, 6 studies on ATCC, 2 studies simultaneously on clinical and standard strains, and finally 1 study on food sample.<br><br>CONCLUSIONS: Our study showed that there was an increasing trend in the number of publications reporting probiotics against biofilm-producing MRSA. The results of this scoping review could use to guide the undertaking of the subsequent systematic reviews. In summary, probiotics with antimicrobial and antibiofilm properties can use as an embedded agent in food products or as a biopharmaceutical in the prevention and treatment of MRSA infections.}, }
@article {pmid36603516, year = {2022}, author = {Ren, S and Yang, Y and Xia, M and Deng, Y and Zuo, Y and Lei, L and Hu, T}, title = {A Chinese herb preparation, honokiol, inhibits Streptococcus mutans biofilm formation.}, journal = {Archives of oral biology}, volume = {147}, number = {}, pages = {105610}, doi = {10.1016/j.archoralbio.2022.105610}, pmid = {36603516}, issn = {1879-1506}, abstract = {OBJECTIVE: This study aimed to investigate the antibiofilm and anticariogenic effects of honokiol, a traditional Chinese medicine, on the cariogenic bacterium Streptococcus mutans (S. mutans).<br><br>DESIGN: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of honokiol on S. mutans UA159 were measured. Then, S. mutans were treated with honokiol at concentrations of 1/2 MIC and 1/4 MIC. Extracellular polysaccharide (EPS) synthesis was assessed with confocal laser scanning microscopy (CLSM) and the anthrone-sulfuric method. Crystal violet staining and scanning electron microscopy (SEM) were used to demonstrate the characteristics and morphology of S. mutans biofilms. Colony-forming unit (CFU) assay was performed to observe the antibacterial effect of honokiol. Lactic acid production of 24-h biofilms was measured by the lactic acid assay. The expression level of caries-related genes (gtfB/C/D, comD/E and ldh) was identified by quantitative real-time PCR (qRTPCR) to explore the relevant mechanism. And the cytotoxic effect on human gingival fibroblasts (HGFs) was evaluated by the Cell Counting Kit-8 (CCK-8) assay.<br><br>RESULTS: The MIC and MBC of honokiol on S. mutans were 30&#xa0;&#x3bc;g/mL and 60&#xa0;&#x3bc;g/mL, respectively. Honokiol inhibited biofilm formation, EPS synthesis and lactic acid production. It also decreased the expression of glucosyltransferases (Gtfs) and quorum sensing (QS) system encoding genes. Moreover, honokiol showed favorable biocompatibility with HGFs.<br><br>CONCLUSIONS: Honokiol has an inhibitory effect on S. mutans and favorable biocompatibility, with application potential as a novel anticaries agent.}, }
@article {pmid36603307, year = {2022}, author = {He, H and Zhang, C and Yang, X and Huang, B and Zhe, J and Lai, C and Liao, Z and Pan, X}, title = {The efficient treatment of mature landfill leachate using tower bipolar electrode flocculation-oxidation combined with electrochemical biofilm reactors.}, journal = {Water research}, volume = {230}, number = {}, pages = {119544}, doi = {10.1016/j.watres.2022.119544}, pmid = {36603307}, issn = {1879-2448}, abstract = {Mature landfill leachate contains high concentrations of organic and inorganic compounds that inhibit the performance of conventional biological treatment. Nowadays, few single treatment techniques could fulfill the requirements of cleaning mature landfill leachate. In this study, a tower bipolar electrode flocculation-oxidation (BEF-O) reactor and an electrochemical biofilm reactor (EBR) combine device was constructed to effectively treat mature landfill leachate. And the removal efficiency and mechanism of various pollutants using the BEF-O reactor were investigated. The BEF-O system with the current density of 100 mA/cm[2] shows excellent treatment efficiency, which can roundly remove most pollutants (NH4[+]-N, COD and heavy metals, etc.), and increase the bioavailability of the effluent to facilitate subsequent EBR treatment. Benefiting from the metabolic stimulation and population selection effect of electric current on microorganisms, EBR has a denser biofilm, stronger anti-pollution load capacity, superior, and stable pollution treatment efficiency. More importantly, the combined device can reduce the concentrations of COD and NH4[+]-N from 6410 to 338 mg/L and 4065 to 4 mg/L, respectively, and has an economical energy consumption of 32.02 kWh/(kg COD) and 54.04 kWh/ (kg NH4[+]-N). To summarize, this research could provide an innovative and industrial application prospect technology for the mature landfill leachate treatment.}, }
@article {pmid36602323, year = {2023}, author = {Regmi, A and Tague, JG and Boas Lichty, KE and Boyd, EF}, title = {A Class IV Adenylate Cyclase, CyaB, Is Required for Capsule Polysaccharide Production and Biofilm Formation in Vibrio parahaemolyticus.}, journal = {Applied and environmental microbiology}, volume = {}, number = {}, pages = {e0187422}, doi = {10.1128/aem.01874-22}, pmid = {36602323}, issn = {1098-5336}, abstract = {Cyclic AMP (cAMP) receptor protein (CRP), encoded by crp, is a global regulator that is activated by cAMP, a second messenger synthesized by a class I adenylate cyclase (AC-I) encoded by cyaA in Escherichia coli. cAMP-CRP is required for growth on nonpreferred carbon sources and is a global regulator. We constructed in-frame nonpolar deletions of the crp and cyaA homologs in Vibrio parahaemolyticus and found that the Δcrp mutant did not grow in minimal media supplemented with nonpreferred carbon sources, but the ΔcyaA mutant grew similarly to the wild type. Bioinformatics analysis of the V. parahaemolyticus genome identified a 181-amino-acid protein annotated as a class IV adenylate cyclase (AC-IV) named CyaB, a member of the CYTH protein superfamily. AC-IV phylogeny showed that CyaB was present in Gammaproteobacteria and Alphaproteobacteria as well as Planctomycetes and Archaea. Only the bacterial CyaB proteins contained an N-terminal motif, HFxxxxExExK, indicative of adenylyl cyclase activity. Both V. parahaemolyticus cyaA and cyaB genes functionally complemented an E. coli ΔcyaA mutant. The Δcrp and ΔcyaB ΔcyaA mutants showed defects in growth on nonpreferred carbon sources and in swimming and swarming motility, indicating that cAMP-CRP is an activator. The ΔcyaA and ΔcyaB single mutants had no defects in these phenotypes, indicating that AC-IV complements AC-I. Capsule polysaccharide and biofilm production assays showed significant defects in the Δcrp, ΔcyaBΔcyaA, and ΔcyaB mutants, whereas the ΔcyaA strain behaved similarly to the wild type. This is consistent with a role of cAMP-CRP as an activator of these phenotypes and establishes a cellular role for AC-IV in capsule and biofilm formation, which to date has been unestablished. IMPORTANCE Here, we characterized the roles of CRP and CyaA in V. parahaemolyticus, showing that cAMP-CRP is an activator of metabolism, motility, capsule production, and biofilm formation. These results are in contrast to cAMP-CRP in V. cholerae, which represses capsule and biofilm formation. Previously, only an AC-I CyaA had been identified in Vibrio species. Our data showed that an AC-IV CyaB homolog is present in V. parahaemolyticus and is required for optimal growth. The data demonstrated that CyaB is essential for capsule production and biofilm formation, uncovering a physiological role of AC-IV in bacteria. The data showed that the cyaB gene was widespread among Vibrionaceae species and several other Gammaproteobacteria, but in general, its phylogenetic distribution was limited. Our phylogenetic analysis also demonstrated that in some species the cyaB gene was acquired by horizontal gene transfer.}, }
@article {pmid36602005, year = {2023}, author = {Zhu, W and Tang, JY and Yu, D and Shen, AG}, title = {Silent Raman imaging of highly effective anti-bacterial activity synchronous with biofilm breakage using poly(4-cyanostyrene)@silver@polylysine nanocomposites.}, journal = {The Analyst}, volume = {}, number = {}, pages = {}, doi = {10.1039/d2an01831d}, pmid = {36602005}, issn = {1364-5528}, abstract = {Biofilms are known to be a great challenge for their anti-bacterial activity as they obstruct drug action for deeper and more thorough bacteria-killing effects. Therefore, developing highly effective antibacterial agents to destroy biofilms and eradicate bacteria is of great significance. Herein, a new type of nanocomposites (denoted as poly(4-cyanostyrene)@silver@polylysine) is proposed, in which polylysine (PLL) could rapidly capture the biofilms and exhibit excellent antibacterial efficacy together with decorated silver (Ag) nanoparticles (NPs) through the charge effect and Ag[+] release. Notably, nearly 100% antibacterial rates against Gram-positive bacterium (Staphylococcus aureus, S. aureus) and Gram-negative bacterium (Escherichia coli, E. coli) were achieved. More importantly, poly(4-cyanostyrene) with biological silent Raman imaging capacity is able to illustrate the relationship between antibacterial efficiency and biofilm breakage. In short, such novel nanocomposites can improve the bioavailability of each component and display tremendous potential in antibacterial applications.}, }
@article {pmid36601891, year = {2023}, author = {Straub, H and Zuber, F and Eberl, L and Maniura-Weber, K and Ren, Q}, title = {In Situ Investigation of Pseudomonas aeruginosa Biofilm Development: Interplay between Flow, Growth Medium, and Mechanical Properties of Substrate.}, journal = {ACS applied materials &amp; interfaces}, volume = {}, number = {}, pages = {}, doi = {10.1021/acsami.2c20693}, pmid = {36601891}, issn = {1944-8252}, abstract = {To better understand the impact of biomaterial mechanical properties and growth medium on bacterial adhesion and biofilm formation under flow, we investigated the biofilm formation ability of Pseudomonas aeruginosa in different media on polydimethylsiloxane (PDMS) of different stiffness in real time using a microfluidic platform. P. aeruginosa colonization was recorded with optical microscopy and automated image analysis. The bacterial intracellular level of cyclic diguanylate (c-di-GMP), which regulates biofilm formation, was monitored using the transcription of the putative adhesin gene (cdrA) as a proxy. Contrary to the previous supposition, we revealed that PDMS material stiffness within the tested range has negligible impact on biofilm development and biofilm structures, whereas culture media not only influence the kinetics of biofilm development but also affect the biofilm morphology and structure dramatically. Interestingly, magnesium rather than previously reported calcium was identified here to play a decisive role in the formation of dense P. aeruginosa aggregates and high levels of c-di-GMP. These results demonstrate that although short-term adhesion assays bring valuable insight into bacterial and material interactions, long-term evaluations are essential to better predict overall biofilm outcome. The microfluidic system developed here presents a valuable application potential for studying biofilm development in situ. .}, }
@article {pmid36599074, year = {2023}, author = {Cuzzucoli Crucitti, V and Ilchev, A and Moore, JC and Fowler, HR and Dubern, JF and Sanni, O and Xue, X and Husband, BK and Dundas, AA and Smith, S and Wildman, JL and Taresco, V and Williams, P and Alexander, MR and Howdle, SM and Wildman, RD and Stockman, RA and Irvine, DJ}, title = {Predictive Molecular Design and Structure-Property Validation of Novel Terpene-Based, Sustainably Sourced Bacterial Biofilm-Resistant Materials.}, journal = {Biomacromolecules}, volume = {}, number = {}, pages = {}, doi = {10.1021/acs.biomac.2c00721}, pmid = {36599074}, issn = {1526-4602}, abstract = {Presented in this work is the use of a molecular descriptor, termed the α parameter, to aid in the design of a series of novel, terpene-based, and sustainable polymers that were resistant to biofilm formation by the model bacterial pathogen Pseudomonas aeruginosa. To achieve this, the potential of a range of recently reported, terpene-derived monomers to deliver biofilm resistance when polymerized was both predicted and ranked by the application of the α parameter to key features in their molecular structures. These monomers were derived from commercially available terpenes (i.e., α-pinene, β-pinene, and carvone), and the prediction of the biofilm resistance properties of the resultant novel (meth)acrylate polymers was confirmed using a combination of high-throughput polymerization screening (in a microarray format) and in vitro testing. Furthermore, monomers, which both exhibited the highest predicted biofilm anti-biofilm behavior and required less than two synthetic stages to be generated, were scaled-up and successfully printed using an inkjet "valve-based" 3D printer. Also, these materials were used to produce polymeric surfactants that were successfully used in microfluidic processing to create microparticles that possessed bio-instructive surfaces. As part of the up-scaling process, a novel rearrangement was observed in a proposed single-step synthesis of α-terpinyl methacrylate via methacryloxylation, which resulted in isolation of an isobornyl-bornyl methacrylate monomer mixture, and the resultant copolymer was also shown to be bacterial attachment-resistant. As there has been great interest in the current literature upon the adoption of these novel terpene-based polymers as green replacements for petrochemical-derived plastics, these observations have significant potential to produce new bio-resistant coatings, packaging materials, fibers, medical devices, etc.}, }
@article {pmid36597590, year = {2022}, author = {El-Sayed, MH and Alshammari, FA and Sharaf, MH}, title = {Antagonistic Potentiality of ActinomyceteDerived Extract with Anti-Biofilm, Antioxidant, and Cytotoxic Capabilities as a Natural Combating Strategy for Multidrug-Resistant ESKAPE Pathogens.}, journal = {Journal of microbiology and biotechnology}, volume = {33}, number = {1}, pages = {1-14}, doi = {10.4014/jmb.2211.11026}, pmid = {36597590}, issn = {1738-8872}, abstract = {The global increase in multidrug-resistant (MDR) bacteria has inspired researchers to develop new strategies to overcome this problem. In this study, 23 morphologically different, soil-isolated actinomycete cultures were screened for their antibacterial ability against MDR isolates of ESKAPE pathogens. Among them, isolate BOGE18 exhibited a broad antibacterial spectrum, so it was selected and identified based on cultural, morphological, physiological, and biochemical characteristics. Chemotaxonomic analysis was also performed together with nucleotide sequencing of the 16S rRNA gene, which showed this strain to have identity with Streptomyces lienomycini. The ethyl acetate extract of the cell-free filtrate (CFF) of strain BOGE18 was evaluated for its antibacterial spectrum, and the minimum inhibitory concentration (MIC) ranged from 62.5 to 250 μg/ml. The recorded results from the in vitro anti-biofilm microtiter assay and confocal laser scanning microscopy (CLSM) of sub-MIC concentrations revealed a significant reduction in biofilm formation in a concentration-dependent manner. The extract also displayed significant scavenging activity, reaching 91.61 ± 4.1% and 85.06 ± 3.14% of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), respectively. A promising cytotoxic ability against breast (MCF-7) and hepatocellular (HePG2) cancer cell lines was obtained from the extract with IC50 values of 47.15 ± 13.10 and 122.69 ± 9.12 μg/ml, respectively. Moreover, based on gas chromatography-mass spectrometry (GC-MS) analysis, nine known compounds were detected in the BOGE18 extract, suggesting their contribution to the multitude of biological activities recorded in this study. Overall, Streptomyces lienomycini BOGE18-derived extract is a good candidate for use in a natural combating strategy to prevent bacterial infection, especially by MDR pathogens.}, }
@article {pmid36597191, year = {2023}, author = {Vasconcelos, BM and Pereira, AMG and Coelho, PAT and Cavalcante, RMB and Carneiro-Torres, DS and Bandeira, PN and da Silva, FF and Rodrigues, THS and Gomes, GA and Carneiro, VA}, title = {Enhancement of chlorhexidine activity against planktonic and biofilm forms of oral streptococci by two Croton spp. essential oils from the Caatinga biome.}, journal = {Biofouling}, volume = {}, number = {}, pages = {1-10}, doi = {10.1080/08927014.2022.2159393}, pmid = {36597191}, issn = {1029-2454}, abstract = {This work investigates the ability of two Croton spp. essential oils (EO) to enhance chlorhexidine (CHX) activity against oral streptococci. EO's chemical composition of Croton argyrophyllus and C. pluriglandulosus was determined by GC-MS/FID. The microbial growth kinetics and minimum inhibitory concentration (MIC) of EOs and CHX were determined, followed by their synergism against S. mutans UA159 and ATCC 25175, S. salivarius ATCC 7073 and S. sp. ATCC 15300. The microplate-based method was used to determine the EO/CHX activity against 24-h-old biofilms. The major compounds were α-pinene (54.74%) and bicyclogermacrene (16.08%) for EOAr and 1,8-cineole (17.41%), methyleugenol (16.06%) and elemicin (15.99%) for EOPg. Both EO had MIC around 16,000 µg/mL. EOs/CHX presented a synergistic effect against most strains (FICi from 0.133 to 0.375), and OE/CHX-treated biofilms showed a reduction in biomass and cell viability compared to CHX, only (p < 0.01). Thus, the EOs works as natural adjuvants for CHX.}, }
@article {pmid36596419, year = {2022}, author = {Niu, SM and Zhang, Q and Sangeetha, T and Chen, L and Liu, LY and Wu, P and Zhang, C and Yan, WM and Liu, H and Cui, MH and Wang, AJ}, title = {Evaluation of the effect of biofilm formation on the reductive transformation of triclosan in cathode-modified electrolytic systems.}, journal = {The Science of the total environment}, volume = {}, number = {}, pages = {161308}, doi = {10.1016/j.scitotenv.2022.161308}, pmid = {36596419}, issn = {1879-1026}, abstract = {The performance of electrochemical reduction is often enhanced by electrode modification techniques. However, there is a risk of microbial colonization on the electrode surface to form biofilms in the treatment of actual wastewater with modified electrodes. In this work, the effects of biofilm formation on modified electrodes with reduced graphene oxide (rGO), platinum/carbon (Pt/C), and carbon nanotube (CNT) were investigated in triclosan (TCS) degradation. With biofilm formation, the TCS degradation efficiencies of carbon cloth (CC), rGO@CC, Pt/C@CC, and CNT@CC decayed to 54.53 %, 59.77 %, 69.19 %, and 53.97 %, respectively, compared to the raw electrodes. Confocal laser scanning microscopy and microbial community analysis revealed that the difference in biofilm thickness and activity were the major influencing factors on the discrepant TCS degradation rather than the microbial community structure. The electrochemical performance tests showed that the biofilm formation increased the ohmic resistance by an order of magnitude in rGO@CC, Pt/C@CC, and CNT@CC, and the charge transfer resistance was increased by 2.45, 3.78, and 7.75 times, respectively. The dechlorination and hydrolysis governed the TCS degradation pathway in all electrolysis systems, and the toxicity of electrochemical reductive products was significantly decreased according to the Toxicity Estimation Software Tool analysis. This study presented a systematic assessment of the biofilm formation on modified electrodes in TCS reduction, and the undisputed experimental outcomes were obtained to enrich the knowledge of implementing modified electrodes for practical applications.}, }
@article {pmid36595339, year = {2022}, author = {Hashemifard Dehkordi, P and Moshtaghi, H and Abbasvali, M}, title = {Effects of magnesium oxide and copper oxide nanoparticles on biofilm formation of Escherichia coli and listeria monocytogenes.}, journal = {Nanotechnology}, volume = {}, number = {}, pages = {}, doi = {10.1088/1361-6528/acab6f}, pmid = {36595339}, issn = {1361-6528}, abstract = {OBJECTIVES: Biofilms formed in food-processing environments are of special importance as they have the potential to act as a persistent source of microbial contamination that may lead to food spoilage or transmission of diseases. The creation of microbial biofilms, which can be a source of food product contamination with food spoilage and food borne pathogenic bacteria, is one of the most critical elements in the food industry. The goal of this study was to see how well magnesium oxide (MgO) and copper oxide (CuO) nanoparticles (NPs) inhibited growth and biofilm formation of two common foodborne bacterial pathogens.<br><br>METHODS AND RESULTS: This study was completed in the year 2020. Resazurin reduction and micro-dilution procedures were used to assess the minimum inhibitory concentration (MIC) of magnesium oxide and copper oxide nanoparticles for Escherichia coli O157: H7 (ATCC 35218) and Listeria monocytogenes (ATCC 19118). The bacterial adhesion to hydrocarbon technique was used to determine the cell-surface hydrophobicity of the selected bacteria. The surface assay was also used to calculate the influence of the NPs coated surfaces on the biofilm formation of the selected bacteria. Magnesium oxide nanoparticles had MICs of 2 and 2 mg/ml, while copper oxide nanoparticles had MICs of 0.16 and 1 mg/ml against E. coli and L. monocytogenes, respectively. At the MIC, the magnesium and copper nanoparticles inhibited biofilm formation of E. coli and L. monocytogenes by 89.9 and 96.6 percent and 93.6 and 98.7 percent, respectively. The hydrophobicity of E. coli and L. monocytogenes was determined to be 74% and 67%, respectively. The surface assay revealed a substantial reduction in bacterial adhesion and colonization on NPs-coated surfaces.<br><br>CONCLUSIONS: Both compounds had inhibitory effects on E. coli and L. monocytogenes, according to our findings. Even at sub-MICs, NPs were found to be able to prevent biofilm development. The microbial count and production of microbial biofilms were reduced on surfaces coated with MgO and CuO nanoparticles.}, }
@article {pmid36593358, year = {2023}, author = {Mahgoub, MA and Abbass, AAG and Abaza, AF and Shoukry, MS}, title = {Probiotic lactic acid bacteria as a means of preventing in vitro urinary catheter colonization and biofilm formation.}, journal = {The Journal of the Egyptian Public Health Association}, volume = {97}, number = {1}, pages = {30}, pmid = {36593358}, issn = {0013-2446}, abstract = {BACKGROUND: Catheter-associated urinary tract infections (CAUTIs) are the most common infections found in healthcare facilities. Urinary catheters predispose the development of CAUTIs by destroying natural barriers and providing a source for infection and biofilm formation (BF). This study aimed to evaluate probiotic lactic acid bacteria (LAB) as a means of preventing in vitro urinary catheter colonization and BF.<br><br>METHODS: Cross-sectional screening, followed by an experimental study, was conducted on 120 catheterized patients admitted to the urology department in a tertiary care hospital for 7 months. The isolated and identified uropathogens were tested for their antimicrobial susceptibility patterns by the disk diffusion method according to Clinical and Laboratory Standards Institute recommendations and examined for their ability to produce biofilms using a microtiter plate (MtP) assay. Five LAB (Lactobacillus acidophilus (L. acidophilus), Bifidobacterium bifidum (B. bifidum), L. paracasei, L. pentosus, and L. plantarum) were identified and examined for preventing in vitro colonization and BF of some isolated uropathogens on Foley urinary catheter surfaces.<br><br>RESULTS: Of the 120 samples collected, 32.5% were found to be associated with CAUTIs. Of isolated organisms, 74.4% were gram-negative bacilli, while gram-positive cocci represented 14%, and only 11.6% were of the Candida species. About two-thirds of isolated uropathogens were biofilm formers. All five probiotic strains had inhibitory effects on the growth of all the uropathogens tested but with varying intensities according to the duration of application after 2, 4, and 6 days.<br><br>CONCLUSIONS: The prevalence of CAUTIs was high, and the predominant bacterial isolates were gram-negative bacilli. Many of the studied uropathogens were biofilm formers. The bacterial isolates had a higher prevalence of resistance to commonly prescribed antimicrobial agents. Probiotics have the potential to prevent in vitro urinary catheter colonization and inhibit BF. Pre-coating urinary catheters with probiotics is recommended after ensuring the safety of probiotics' use in vivo by carrying out further large-scale studies.}, }
@article {pmid36592830, year = {2022}, author = {Tong, CY and Chua, MX and Tan, WH and Derek, CJC}, title = {Microalgal extract as bio-coating to enhance biofilm growth of marine microalgae on microporous membranes.}, journal = {Chemosphere}, volume = {}, number = {}, pages = {137712}, doi = {10.1016/j.chemosphere.2022.137712}, pmid = {36592830}, issn = {1879-1298}, abstract = {Microalgal biofilm is a popular platform for algal production, nutrient removal and carbon capture; however, it suffers from significant biofilm exfoliation under shear force exposure. Hence, a biologically-safe coating made up of algal extracellular polymeric substances (EPS) was utilized to secure the biofilm cell retention and cell loading on commercial microporous membrane (polyvinylidene fluoride), making the surfaces more hydrophobic (contact angle increase an up to 12°). Results demonstrated that initial cell adhesion of three marine microalgae (Amphora coffeaeformis, Cylindrotheca fusiformis and Navicula incerta) was enhanced by at least 1.3 times higher than that of pristine control within only seven days with minimized biofilm exfoliation issue due to uniform distribution of sticky transparent exopolymer particles. Bounded extracellular polysaccharide gathered was approximately 23% higher on EPS-coated membranes to improve the biofilm's hydraulic resistance, whereas bounded extracellular protein would only be substantially elevated after the attached cells re-accommodate themselves onto the EPS pre-coating of themselves. In accounting the rises of hydrophobic protein content, biofilm was believed to be more stabilized, presumably via hydrophobic interactions. EPS biocoating would generate a groundswell of interest for bioprocess intensifications though there are lots of inherent technical and molecular challenges to be further investigated in future.}, }
@article {pmid36592808, year = {2022}, author = {Lan, M and Yin, Q and Wang, J and Li, M and Li, Y and Li, B}, title = {Heterotrophic nitrification-aerobic denitrification performance of a novel strain, Pseudomonas sp. B-1, isolated from membrane aerated biofilm reactor.}, journal = {Environmental research}, volume = {}, number = {}, pages = {115199}, doi = {10.1016/j.envres.2022.115199}, pmid = {36592808}, issn = {1096-0953}, abstract = {A heterotrophic nitrification-aerobic denitrification (HN-AD) strain isolated from membrane aerated biofilm reactor (MABR) was identified as Pseudomonas sp. B-1, which could effectively utilize multiple nitrogen sources and preferentially consume NH4-N. The maximum degradation efficiencies of NO3-N, NO2-N and NH4-N were 98.04%, 94.84% and 95.74%, respectively. The optimal incubation time, shaking speed, carbon source, pH, temperature and C/N ratio were 60 h, 180 rpm, sodium succinate, 8, 30 °C and 25, respectively. The strain preferred salinity of 1.5% and resisted heavy metals in the order of Mn[2+] > Co[2+] > Zn[2+] > Cu[2+]. It can be preliminarily speculated from the results of enzyme assay that the strain removed nitrogen via full nitrification-denitrification pathway. The addition of strain into the conventional MABR significantly intensified the HN-AD performance of the reactor. The relative abundance of the functional bacteria including Flavobacterium, Pseudomonas, Paracoccus, Azoarcus and Thauera was obviously increased after the bioaugmentation. Besides, the expression of the HN-AD related genes in the biofilm was also strengthened. Thus, strain B-1 had great application potential in nitrogen removal process.}, }
@article {pmid36592641, year = {2022}, author = {Upadhayay, A and Pal, D and Kumar, A}, title = {Substantial relation between the bacterial biofilm and oncogenesis progression in host.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {105966}, doi = {10.1016/j.micpath.2022.105966}, pmid = {36592641}, issn = {1096-1208}, abstract = {Globally, bacteria are well-known microorganisms for bacterial biofilm infection. Bacterial biofilm has generated antibiotic resistance and led the persistent infection. But new complications arise with a biofilm that bacterial biofilm shows the new association with oncogenesis. Some bacteria have a carcinogenic nature at the chronic infection stage like Salmonella Typhi, Helicobacter pylori. Thus, biofilm has a significant role in oncogenesis. Few pieces of evidence also support that the bacterial biofilm has a potential role to develop oncogenesis in the human body. Bacterial biofilm is responsible to induce chronic inflammation and is the main basis for the oncogenesis process. But bacterial biofilm association with the oncogenesis mechanism is unknown yet. This article focuses on the function of bacterial biofilm in tumor formation and the mechanism that encourages the oncogenesis and provide a possible and interesting hypothesis involved in between biofilm and host oncogenesis progression. The discussed relationship will provide a sound direction in the field of oncology and concept may give an informative direction in diagnosis and treatment. Bacterial biofilm behavior could be significantly linked with cancer cell formation. This article attracts the attention of researchers of the field because biofilm mediated oncogenesis further indicate towards an important issue in human health.}, }
@article {pmid36590419, year = {2022}, author = {Xie, Y and Wang, L and Yang, Y and Zha, L and Zhang, J and Rong, K and Tang, W and Zhang, J}, title = {Antibacterial and anti-biofilm activity of diarylureas against Enterococcus faecium by suppressing the gene expression of peptidoglycan hydrolases and adherence.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1071255}, pmid = {36590419}, issn = {1664-302X}, abstract = {Enterococcus faecium (E. faecium) is a clinical multidrug-resistant pathogen causing life-threatening infection, which makes it important to discover antibacterial agents with novel scaffolds and unique mechanism. In this study, the diarylurea scaffold was found to have potent antibacterial effect on E. faecium. Diarylurea ZJ-2 with benign drug-like property exhibited potent antibacterial and anti-biofilm activity through inhibiting the genes expression of NlpC/p60 hydrolase-secreted antigen A (sagA) and autolysins (atlA), down-regulating the expression of biofilm adherence related genes aggregation substance (agg), enterococcal surface protein (esp) against E. faecium. Moreover, ZJ-2 can be docked into SagA to inhibit daughter cell separation. In a mouse model of abdominal infection, ZJ-2 decreased the bacterial load and the level of IL-6 and TNF-α in a time-dependent manner. Overall, these findings indicated that diarylurea ZJ-2 has the potential to be developed as a therapeutic agent to treat drug-resistant enterococci and biofilm-related infections.}, }
@article {pmid36589237, year = {2022}, author = {Song, N and De Greve, H and Wang, Q and Hernalsteens, JP and Li, Z}, title = {Plasmid parB contributes to uropathogenic Escherichia coli colonization in vivo by acting on biofilm formation and global gene regulation.}, journal = {Frontiers in molecular biosciences}, volume = {9}, number = {}, pages = {1053888}, pmid = {36589237}, issn = {2296-889X}, abstract = {The endogenous plasmid pUTI89 harbored by the uropathogenic Escherichia coli (UPEC) strain UTI89 plays an important role in the acute stage of infection. The partitioning gene parB is important for stable inheritance of pUTI89. However, the function of partitioning genes located on the plasmid in pathogenesis of UPEC still needs to be further investigated. In the present study, we observed that disruption of the parB gene leads to a deficiency in biofilm formation in vitro. Moreover, in a mixed infection with the wild type strain and the parB mutant, in an ascending UTI mouse model, the mutant displayed a lower bacterial burden in the bladder and kidneys, not only at the acute infection stage but also extending to 72 hours post infection. However, in the single infection test, the reduced colonization ability of the parB mutant was only observed at six hpi in the bladder, but not in the kidneys. The colonization capacity in vivo of the parB-complemented strain was recovered. qRT-PCR assay suggested that ParB could be a global regulator, influencing the expression of genes located on both the endogenous plasmid and chromosome, while the gene parA or the operon parAB could not. Our study demonstrates that parB contributes to the virulence of UPEC by influencing biofilm formation and proposes that the parB gene of the endogenous plasmid could regulate gene expression globally.}, }
@article {pmid36588982, year = {2023}, author = {Shaikh, S and Rashid, N and Onwusogh, U and McKay, G and Mackey, HR}, title = {Effect of nutrients deficiency on biofilm formation and single cell protein production with a purple non-sulphur bacteria enriched culture.}, journal = {Biofilm}, volume = {5}, number = {}, pages = {100098}, pmid = {36588982}, issn = {2590-2075}, abstract = {Purple non-sulphur bacteria (PNSB) are of interest for biorefinery applications to create biomolecules, but their production cost is expensive due to substrate and biomass separation costs. This research has utilized fuel synthesis wastewater (FSW) as a low-cost carbon-rich substrate to produce single-cell protein (SCP) and examines PNSB biofilm formation using this substrate to achieve a more efficient biomass-liquid separation. In this study, PNSB were grown in Ca, Mg, S, P, and N-deficient media using green shade as biofilm support material. Among these nutrient conditions, only N-deficient and control (nutrient-sufficient) conditions showed biofilm formation. Although total biomass growth of the control was 1.5 times that of the N-deficient condition and highest overall, the total biofilm-biomass in the N-deficient condition was 2.5 times greater than the control, comprising 49% of total biomass produced. Total protein content was similar between these four biomass samples, ranging from 35.0 ± 0.2% to 37.2 ± 0.0%. The highest protein content of 44.7 ± 1.3% occurred in the Mg-deficient condition (suspended biomass only) but suffered from a low growth rate. Overall, nutrient sufficient conditions are optimal for overall protein productivity and dominated by suspended growth, but where fixed growth systems are desired for cost-effective harvesting, N-deficient conditions provide an effective means to maximize biofilm production without sacrificing protein content.}, }
@article {pmid36588392, year = {2023}, author = {Rezaei, T and Kamounah, FS and Khodadadi, E and Mehramouz, B and Gholizadeh, P and Yousefi, L and Ganbarov, K and Ghotaslou, R and Yousefi, M and Asgharzadeh, M and Eslami, H and Taghizadeh, S and Pirzadeh, T and Kafil, HS}, title = {Comparing proteome changes involved in biofilm formation by Streptococcus mutans after exposure to sucrose and starch.}, journal = {Biotechnology and applied biochemistry}, volume = {}, number = {}, pages = {}, doi = {10.1002/bab.2442}, pmid = {36588392}, issn = {1470-8744}, abstract = {Streptococcus mutans is a main organism of tooth infections including tooth decay and periodontitis. The aim of this study was to assess the influence of sucrose and starch on biofilm formation and proteome profile of S. mutans ATCC 35668 strain. The biofilm formation was assessed by microtiter plating method. Changes in bacterial proteins after exposure to sucrose and starch carbohydrates were analyzed using matrix-assisted laser desorption/ionization mass spectrometry. The biofilm formation of S. mutans was increased to 391.76% in 1% sucrose concentration, 165.76% in 1% starch and 264.27% in the 0.5% sucrose plus 0.5% Starch in comparison to biofilm formation in the media without sugars. The abundance of glutamines, adenylate kinase, and 50S ribosomal protein L29 were increased under exposure to sucrose. Upregulation of Lactate utilization protein C, 5-hydroxybenzimidazole synthase BzaA, and 50S ribosomal protein L16 were formed under starch exposure. Ribosome-recycling factor, Peptide chain release factor 1, and Peptide methionine sulfoxide reductase MsrB were upregulated under exposure to sucrose in combination to starch. The results demonstrated that the carbohydrates increase microbial pathogenicity. In addition, sucrose and starch carbohydrates can induce biofilm formation of S. mutans via various mechanisms such as changes in the expression of special proteins. This article is protected by copyright. All rights reserved.}, }
@article {pmid36587926, year = {2022}, author = {Siqueira, FDS and Siqueira, JD and Denardi, LB and Moreira, KS and Lima Burgo, TA and de Lourenço Marques, L and Machado, AK and Davidson, CB and Chaves, OA and Anraku de Campos, MM and Back, DF}, title = {Antibacterial, antifungal, and anti-biofilm effects of sulfamethoxazole-complexes against pulmonary infection agents.}, journal = {Microbial pathogenesis}, volume = {}, number = {}, pages = {105960}, doi = {10.1016/j.micpath.2022.105960}, pmid = {36587926}, issn = {1096-1208}, abstract = {Antibiotic resistance associated with pulmonary infection agents has become a public health problem, being considered one of the main priorities for immediate resolution. Thus, to increase the therapeutic options in the fight against resistant microorganisms, the synthesis of molecules from pre-existing drugs has shown to be a promising alternative. In this sense, the present work reports the synthesis, characterization, and biological evaluation (against fungal and bacterial agents that cause lung infections) of potential metallodrugs based on sulfamethoxazole complexed with Au[I], Ag[I], Hg[II], Cd[II], Ni[II], and Cu[II]. The minimal inhibitory concentration (MIC) value was used to evaluate the antifungal and antibacterial properties of the compounds. In addition, it was also evaluated the antibiofilm capacity in Pseudomonas aeruginosa, through the quantification of its biomass and visualization using atomic force microscopy. For each case, molecular docking calculations were carried out to suggest the possible biological target of the assayed inorganic complexes. Our results indicated that the novel inorganic complexes are better antibacterial and antifungal than the commercial antibiotic sulfamethoxazole, highlighting the Ag[I]-complex, which was able to inhibit the growth of microorganisms that cause lung diseases with concentrations in the 2-8 μg mL[-1] range, probably at targeting dihydropteroate synthetase - a key enzyme involved in the folate synthesis. Furthermore, sulfamethoxazole complexes were able to inhibit the formation of bacterial biofilms at significantly lower concentrations than free sulfamethoxazole, probably mainly targeting the active site of LysR-type transcriptional regulator (PqsR). Overall, the present study reports preliminary results that demonstrate the derivatization of sulfamethoxazole with transition metal cations to obtain potential metallodrugs with applications as antimicrobial and antifungal against pulmonary infections, being an alternative for drug-resistant strains.}, }
@article {pmid36587206, year = {2022}, author = {Li, R and Liang, Q and Tian, S and Zhang, Y and Liu, S and Ou, Q and Chen, Z and Wang, C}, title = {Hemolysin function of Listeria is related to biofilm formation: transcriptomics analysis.}, journal = {Veterinary research}, volume = {53}, number = {1}, pages = {113}, pmid = {36587206}, issn = {1297-9716}, abstract = {Listeriolysin O (LLO) is the main virulence protein of Listeria monocytogenes (LM), that helps LM escape lysosomes. We previously found that the cellular immune response elicited by L.ivanovii (LI) is weaker than that elicited by LM. We speculated that this may be related to the function of ivanolysin O (ILO). Here, we constructed hemolysin gene deletion strain, LIΔilo, and a modified strain, LIΔilo::hly, in which ilo was replaced by hly. Prokaryotic transcriptome sequencing was performed on LI, LIΔilo, and LIΔilo::hly. Transcriptome differences between the three strains were compared, and genes and pathways with significant differences between the three strains were analyzed. Prokaryotic transcriptome sequencing results revealed the relationship of ilo to the ribosome, quorum sensing, and phosphotransferase system (PTS) pathways, etc. LIΔilo exhibited attenuated biofilm formation ability compared to LI. Biofilm formation was significantly recovered or even increased after replenishing hly. After knocking out ilo, the relative expression levels of some virulence genes, including sigB, prfA, actA, smcL, and virR, were up-regulated compared to LI. After replenishing hly, these genes were down-regulated compared to LIΔilo. The trend and degree of such variation were not completely consistent when cultured in media containing only monosaccharides or disaccharides. The results confirmed that hemolysin is related to some important biological properties of Listeria, including biofilm formation and virulence gene expression levels. This is the first comprehensive study on ILO function at the transcriptomic level and the first evidence of a relationship between Listeria hemolysin and biofilm formation.}, }
@article {pmid36586714, year = {2022}, author = {Zhao, ZC and Fan, SQ and Lu, Y and Dang, CC and Wang, X and Liu, BF and Xing, DF and Ma, J and Ren, NQ and Wang, Q and Xie, GJ}, title = {Reactivated biofilm coupling n-DAMO with anammox achieved high-rate nitrogen removal in membrane aerated moving bed biofilm reactor.}, journal = {Environmental research}, volume = {}, number = {}, pages = {115184}, doi = {10.1016/j.envres.2022.115184}, pmid = {36586714}, issn = {1096-0953}, abstract = {As a promising technology, the combination of nitrate/nitrite-dependent anaerobic methane oxidation (n-DAMO) with Anammox offers a solution to achieve effective and sustainable wastewater treatment. However, this sustainable process faces challenges to accumulate sufficient biomass for reaching practical nitrogen removal performance. This study developed an innovative membrane aerated moving bed biofilm reactor (MAMBBR), which supported sufficient methane supply and excellent biofilm attachment, for cultivating biofilms coupling n-DAMO with Anammox. Biofilms were developed rapidly on the polyurethane foam with the supply of ammonium and nitrate, achieving the bioreactor performance of 275 g N m[-3] d[-1] within 102 days. After the preservation at -20 °C for 8 months, the biofilm was successfully reactivated and achieved 315 g N m[-3] d[-1] after 188 days. After reactivation, MAMBBR was applied to treat synthetic sidestream wastewater. Up to 99.9% of total nitrogen was removed with the bioreactor performance of 4.0 kg N m[-3] d[-1]. Microbial community analysis and mass balance calculation demonstrated that n-DAMO microorganisms and Anammox bacteria collectively contributed to nitrogen removal in MAMBBR. The MAMBBR developed in this study provides an ideal system of integrating n-DAMO with Anammox for sustainable wastewater treatment.}, }
@article {pmid36586294, year = {2022}, author = {Fu, D and Wu, J and Wu, X and Shao, Y and Song, X and Tu, J and Qi, K}, title = {The two-component system histidine kinase EnvZ contributes to Avian pathogenic Escherichia coli pathogenicity by regulating biofilm formation and stress responses.}, journal = {Poultry science}, volume = {102}, number = {2}, pages = {102388}, doi = {10.1016/j.psj.2022.102388}, pmid = {36586294}, issn = {1525-3171}, abstract = {EnvZ, the histidine kinase (HK) of OmpR/EnvZ, transduces osmotic signals in Escherichia coli K12 and affects the pathogenicity of Shigella flexneri and Vibrio cholera. Avian pathogenic E. coli (APEC) is an extra-intestinal pathogenic E. coli (ExPEC), causing acute and sudden death in poultry and leading to severe economic losses to the global poultry industry. How the functions of EnvZ correlate with APEC pathogenicity was still unknown. In this study, we successfully constructed the envZ mutant strain AE17ΔenvZ and the inactivation of envZ significantly reduced biofilms and altered red, dry, and rough (rdar) morphology. In addition, AE17ΔenvZ was significantly less resistant to acid, alkali, osmotic, and oxidative stress conditions. Deletion of envZ significantly enhanced sensitivity to specific pathogen-free (SPF) chicken serum and increased adhesion to chicken embryonic fibroblast DF-1 cells and elevated inflammatory cytokine IL-1β, IL6, and IL8 expression levels. Also, when compared with the WT strain, AE17ΔenvZ attenuated APEC pathogenicity in chickens. To explore the molecular mechanisms underpinning envZ in APEC17, we compared the WT and envZ-deletion strains using transcriptome analyses. RNA-Seq results identified 711 differentially expressed genes (DEGs) in the envZ mutant strain and DEGs were mainly enriched in outer membrane proteins, stress response systems, and TCSs. Quantitative real-time reverse transcription PCR (RT-qPCR) showed that EnvZ influenced the expression of biofilms and stress responses genes, including ompC, ompT, mlrA, basR, hdeA, hdeB, adiY, and uspB. We provided compelling evidence showing EnvZ contributed to APEC pathogenicity by regulating biofilms and stress response expression.}, }
@article {pmid36586061, year = {2022}, author = {Ankudze, B and Neglo, D}, title = {Green synthesis of silver nanoparticles from peel extract of Chrysophyllum albidum fruit and their antimicrobial synergistic potentials and biofilm inhibition properties.}, journal = {Biometals : an international journal on the role of metal ions in biology, biochemistry, and medicine}, volume = {}, number = {}, pages = {}, pmid = {36586061}, issn = {1572-8773}, abstract = {Current methods for green synthesis of metal nanoparticles often require continuous harvesting of fresh bio-materials for every synthesis cycle. Practices and procedures that economize bio-materials need to be employed if green synthesis could become a sustainable and eco-friendly method for synthesizing metal nanoparticles. This study explores Chrysophyllum albidum peels (mostly regarded as waste) to prepare silver nanoparticles (Alb-AgNPs). The technique employed in the synthesis allows repeated use of the peels, thus, reducing the heavy dependence on bio-materials. The optical and structural properties of the Alb-AgNPs were studied with Scanning electron microscope, Fourier transform infrared spectrometer, UV-Vis spectrophotometer and powder X-ray diffractometer. The antimicrobial properties of the Alb-AgNPs were studied with selected microorganisms namely; S. aureus, E. coli, K. pneumoniae, B. subtilis, S. mutans, P. aeruginosa, S. typhi, and Candida albicans. High inhibitory activity against the microorganisms were exhibited with MICs ranging from 15.62 to 1000 µg/mL. Again, the Alb-AgNPs showed the ability to enhance the efficacy of standard antimicrobial agents. The results of the combined interaction with standard antibacterial and antifungal agents ranged from synergistic to antagonistic effects against the tested microorganisms. In addition, the Alb-AgNPs could serve as a biofilm inhibitor with the highest percent inhibition of about 92% against methicillin-resistant Staphylococcus aureus. The results from this study thus provide access to the simple, sustainable, economic and eco-friendly synthesis of silver nanoparticles with efficient antimicrobial properties as drug candidates as a means of overcoming the prevailing antibiotic resistance menaces.}, }
@article {pmid36585632, year = {2022}, author = {Hamed, SA and Shabayek, S and Hassan, HY}, title = {Biofilm elimination from infected root canals using four different single files.}, journal = {BMC oral health}, volume = {22}, number = {1}, pages = {660}, pmid = {36585632}, issn = {1472-6831}, abstract = {INTRODUCTION: Enterococcus faecalis (E. faecalis) is the most commonly isolated bacterium from infected root canals. It is found in the form of a biofilm, which makes it more resistant to antimicrobials, and requires optimal chemomechanical strategies to maximize root canal disinfection.<br><br>AIM: To evaluate the efficacy of 4 different endodontic file systems against E. faecalis biofilm growth in root canals using colony-forming units per milliliter (CFU/mL) and scanning electron microscope (SEM).<br><br>METHODS: Eighty-five extracted human mandibular premolars with straight root canals and apical diameters not larger than the #15&#xa0;K-file were randomly selected. After performing a pilot study (n&#x2009;=&#x2009;15) to determine the ideal incubation period for E. faecalis biofilm development, sixty-five root canals were infected with E. faecalis, incubated for 3 weeks, and then mechanically prepared using one of four single files (XP-endo Shaper, Hyflex EDM, One Curve, and Fanta. AFTM F One) (n&#x2009;=&#x2009;15). Five infected root canals were excluded for the positive control. Five non-contaminated root canals were included for the negative control. Samples were collected using sterile paper points pre- and post-instrumentation to determine the bacterial load (CFU/mL). Root canals from each group were topographically evaluated at the coronal, middle, and apical segments using scanning electron microscope (SEM). Bacterial reduction data were estimated and statistically analyzed by Kruskal-Wallis and Mann-Whitney U tests (post hoc test) (P&#x2009;&#x2264;&#x2009;.05).<br><br>RESULTS: XP-endo Shaper, Hyflex DEM, and One Curve significantly could eradicate E. faecalis biofilms in infected root canals with no significant difference among them compared to Fanta. AF&#x2122; F One.<br><br>CONCLUSION: None of the systems were capable of completely eliminating biofilms. XP-endo Shaper, Hyflex EDM, and One Curve mechanically eliminated E. faecalis biofilms compared to Fanta. AF&#x2122; F One from infected root canals.}, }
@article {pmid36585548, year = {2022}, author = {Salimi, F and Imanparast, S}, title = {Characterization of Probiotic Pichia sp. DU2-Derived Exopolysaccharide with Oil-in-Water Emulsifying and Anti-biofilm Activities.}, journal = {Applied biochemistry and biotechnology}, volume = {}, number = {}, pages = {}, pmid = {36585548}, issn = {1559-0291}, abstract = {Probiotic-derived exopolysaccharides are considered as promising sources of carbohydrate with extensive applications in many industries. In the current study, yeast strains were isolated from chicken ingluvies and gizzard samples. According to molecular identification, EPS-producing yeast (Pichia sp. DU2) showed the most similarity to Pichia cactophila (99.67%). Pichia sp. DU2 showed probiotic properties. EPS of Pichia sp. DU2 showed emulsifying activity. The formed emulsions showed 53% (colza oil) and 100% (p-xylene) stability after 24 h. These emulsions were oil-in-water and have stability in the presence of NaCl, KCl, and also acidic and basic conditions. Also, the EPS showed anti-biofilm (29.7-47.6% and 19.06-55.26% against B. cereus and Y. enterocolitica, respectively) and flocculating activities (31.4%). FT-IR showed the presence of various functional groups in EPS structure. Also, its heteropolysaccharide nature was revealed in [1]H-NMR and HPLC analysis. This emulsifying EPS showed significant thermal stability and negative zeta potential, which make it a promising carbohydrate for various industries. Finally, according to the predicted model, the maximal EPS production was achieved at reaction time 36 h, pH 6, yeast extract concentration 1.0%, and sucrose concentration 5%. Pichia sp. DU2 with probiotic properties and producing EPS with emulsifying, anti-biofilm, and flocculating activities can be considered as promising yeast strain in various industries like food and pharmaceutical industries.}, }
@article {pmid36585511, year = {2022}, author = {Bai, X and Shen, Y and Zhang, T and Meng, R and Zhang, Y and Deng, Y and Guo, N}, title = {Anti-biofilm activity of biochanin A against Staphylococcus aureus.}, journal = {Applied microbiology and biotechnology}, volume = {}, number = {}, pages = {}, pmid = {36585511}, issn = {1432-0614}, abstract = {Biofilm-forming Staphylococcus aureus can easily accumulate on various food contact surfaces which induce cross-contamination and are difficult to eliminate in the food industry. This study aimed to evaluate the anti-biofilm effects of natural product biochanin A against S. aureus. Results showed that biochanin A effectively eradicated established S. aureus biofilms on different food-contact materials. Fluorescence microscopic analyses suggested that biochanin A disintegrated the established biofilms by dissociate extracellular polymeric substance (EPS) in matrix. In addition, biochanin A at the sub-MIC concentration also effectively inhibited the biofilm formation by regulating the expression of biofilm-related genes (icaA, srtA, eno) and suppressing the release of EPS in biofilm matrix. Molecular docking also demonstrated that biochanin A conducted strong interactions with biofilm-related proteins (Ica A, Sortase A, and Enolase). These findings demonstrated that biochanin A has the potential to be developed as a potent agent against S. aureus biofilm in food industries. KEY POINTS: • Anti-biofilm effect of biochanin A against S. aureus was revealed for the first time. • Biofilm of S. aureus on various food-contact surfaces were efficiently eradicated. • Biochanin A prevented S. aureus biofilm formation via reducing EPS production.}, }
@article {pmid36583292, year = {2022}, author = {Andhare, MG and Shetty, S and Vivekanandan, G and Shetty, RM and Rahman, B and Shetty, SR and Srinivasa, TS and Desai, V}, title = {Clinical efficacy of Green Tea, Aloe Vera and Chlorhexidine mouthwashes in the treatment of dental biofilm induced gingivitis: A multi-arm, double-blinded, randomized controlled clinical trial.}, journal = {International journal of dental hygiene}, volume = {}, number = {}, pages = {}, doi = {10.1111/idh.12664}, pmid = {36583292}, issn = {1601-5037}, abstract = {OBJECTIVE: This multi-arm, randomized, double-blinded, controlled clinical trial was designed to evaluate the clinical efficacy of 0.5% Green Tea (GT), 0.2 % Chlorhexidine (CHX) and Aloe Vera (AV) mouthwash as compared to the control (CNT) group (scaling and polishing alone with no mouthwash) in the management of dental biofilm induced gingivitis among 18-40-year-old patients.<br><br>MATERIAL AND METHODS: Sixty patients with generalized dental biofilm-induced gingivitis) were randomly allocated to four study groups (n=15 each) for treatment, namely, Group GT, Group CHX, Group AV and Group CNT after scaling and polishing were administered to all the patients. Plaque index (PI), gingival index (GI) and sulcular bleeding index (SBI) were recorded at baseline, 14[th,] and 21[st] day.<br><br>RESULTS: PI, GI and SBI at various time intervals (baseline, 14[th] day and 21[st] day) showed high statistically significant differences within the group (p <&#x2009;0.01). Among these, the maximum percentage change was found in the CHX group followed by GT when evaluated from baseline to 21[st] day. The least percentage change was found in the AV group for PI and GI while the CNT group showed the least percentage change for sulcular index when evaluated from 14[th] day to 21[st] day. Inter-group results showed high statistically significant differences (p <&#x2009;0.01) for PI and GI when evaluated between baseline to 14[th] day and baseline to 21[st] day. SBI also showed statistically significant differences (p <&#x2009;0.05) when evaluated between baselines to 14[th] day and baseline to 21[st] day.<br><br>CONCLUSION: Green tea mouthwash displayed a significant reduction in plaque index, gingival index, and sulcular bleeding index. 0.5% Green tea catechin has equivalent anti-plaque efficacy as 0.2% Chlorhexidine gluconate and can be considered a potent alternative to prevent and treat gingival diseases.}, }
@article {pmid36583044, year = {2022}, author = {Li, L and Yu, T and Yuan, L and Doulgeraki, AI and Iseppi, R}, title = {Editorial: Biofilm formation and quorum sensing of foodborne microorganism.}, journal = {Frontiers in microbiology}, volume = {13}, number = {}, pages = {1107603}, pmid = {36583044}, issn = {1664-302X}, }
@article {pmid36580984, year = {2022}, author = {Xu, L and Yang, Y and Su, J and He, C and Shi, J and Yan, H and Wei, H}, title = {Simultaneous removal of nitrate, lead, and tetracycline by a fixed-biofilm reactor assembled with kapok fiber and sponge iron: Comparative analysis of operating conditions and biotic community.}, journal = {Environmental research}, volume = {}, number = {}, pages = {115163}, doi = {10.1016/j.envres.2022.115163}, pmid = {36580984}, issn = {1096-0953}, abstract = {In recent years, under the condition of lack of carbon source, the presence of composite micro-pollutants make the removal of nitrate seriously damaged, and to find a suitable way to solve this problem is imminent. A fixed-biofilm carrier modified by mixing sponge iron (SI) and kapok fiber (KF) combined with strain Zoogloea sp. FY6 was constructed in this study to get a fixed-biofilm reactor with merit denitrification performance. By adjusting the operation parameters, it can be concluded that when the carbon to nitrogen (C/N) ratio was 1.5, the hydraulic retention time (HRT) was 6.0 h, and the pH was 6.0, the nitrate removal efficiency (NRE) of the fixed-biofilm reactor was up to 95.4% (2.95 mg L[-1] h[-1]). In addition, the fixed-biofilm reactor constructed in this study can remove lead (Pb[2+]) and tetracycline (TC) excellently in the presence of SI and Zoogloea sp. FY6, and the denitrification performance can still maintain a high level under the influence of different concentrations of Pb[2+] and TC. Furthermore, the addition of SI not only removes the compound pollutants, but also protects the toxicity of the pollutant inflow in the bioreactor, and the metabolic process of microorganisms in the bioreactor also removes some of the compound pollutants. The high-throughput data showed the abundance of strain Zoogloea sp. FY6 was still the highest value under the influence of various pollutants, and the metagenomic prediction showed that the fixed-biofilm reactor had perfect denitrification process and iron redox cycle benefits. This study provides a valuable reference for sustainable utilization of natural biological resources and reduction of material costs in wastewater treatment plants (WWTPs).}, }
@article {pmid36580768, year = {2022}, author = {Ramachandra, SS and Abdal-Hay, A and Han, P and Lee, RSB and Ivanovski, S}, title = {Fabrication and characterization of a 3D polymicrobial microcosm biofilm model using melt electrowritten scaffolds.}, journal = {Biomaterials advances}, volume = {145}, number = {}, pages = {213251}, doi = {10.1016/j.bioadv.2022.213251}, pmid = {36580768}, issn = {2772-9508}, abstract = {The majority of current biofilm models or substrates are two-dimensional (2D) and support biofilm growth in the horizontal plane only. Three-dimensional (3D) substrates may support both horizontal and vertical biofilm growth. This study compared biofilm growth quantity and quality between highly porous 3D micrometric fibrous scaffolds and 2D film substrates fabricated from medical grade polycaprolactone (mPCL). Melt electrowriting (MEW), a high-resolution additive manufacturing technology, was employed to design orderly aligned fine (~12 μm) fibre-based 3D scaffolds, while 2D films were fabricated by a casting method. The 3D scaffolds with a controlled pore size of 100 and 250 μm and thickness of ~0.8 mm and 2D films were incubated in pooled saliva collected from six volunteers for 1, 2, 4, 7 and 10 days at 37 °C to facilitate polymicrobial biofilm formation. Crystal violet assay demonstrated greater biofilm biomass in 3D MEW scaffolds than in 2D films. Biofilm thickness in 3D scaffolds was significantly higher compared to the biofilm thickness in 2D films. Both biovolume and substratum coverage of the biofilms was higher in the 3D scaffolds compared to 2D films. Polymeric bridges, pores, and channels characteristic of biofilms could be demonstrated by scanning electron microscopy. 16S rRNA sequencing demonstrated that the polymicrobial biofilms in the 3D scaffolds were able to retain 60-70 % of the original inoculum microbiome after 4 days. The MEW-fabricated 3D fibrous scaffold is a promising substrate for supporting multidirectional biofilm growth and modelling of a polymicrobial microcosm.}, }
@article {pmid36580163, year = {2022}, author = {Ma, N and Guo, P and Chen, J and Qi, Z and Liu, C and Shen, J and Sun, Y and Chen, X and Chen, GQ and Ma, X}, title = {Poly-β-hydroxybutyrate alleviated diarrhea and colitis via Lactobacillus johnsonii biofilm-mediated maturation of sulfomucin.}, journal = {Science China. Life sciences}, volume = {}, number = {}, pages = {}, pmid = {36580163}, issn = {1869-1889}, abstract = {Maintainance of sulfomucin is a key end point in the treatment of diarrhea and inflammatory bowel disease (IBD). However, the mechanisms underlying the microbial sense to sulfomucin are poorly understood, and to date, there are no therapies targeting the secretion and maturation of sulfomucin in IBD. Herein, we biosynthesized poly-β-hydroxybutyrate (PHB) and found that PHB could alleviate inflammation caused by diarrhea and colitis by enhancing the differentiation of sulfomucin. Microbiota transplantation and clearance together demonstrate that PHB promoting sulfomucin is mediated by Lactobacillus johnsonii (L. johnsonii). Further studies revealed that PHB provides a favorable niche for L. johnsonii biofilm formation to resist disturbance and support its growth. L. johnsonii-biofilm alleviates colitis by regulating fucose residues to promote goblet cell differentiation and subsequent sulfomucin maturation. Importantly, PHB alleviates colitis by enhancing sulfomucin secretion and maturation in a L. johnsonii-dependent manner. PHB represents a class of guardians, acting as a safe probiotic-biofilm delivery system that significantly promotes probiotic proliferation. Altogether, this study adds weight to the possible role of probiotics and functional materials in the treatment of intestinal inflammation. The application of PHB and biofilm self-coating L. johnsonii carries high translational potential and may be of clinical relevance.}, }
@article {pmid36579869, year = {2022}, author = {Han, W and Zhou, J and Sheng, D and Wu, D and Zhou, H and Yang, Z and Yin, J and Xia, C and Kan, Y and He, J}, title = {Integration of a pure moving bed biofilm reactor process into a large micro-polluted water treatment plant.}, journal = {Water science and technology : a journal of the International Association on Water Pollution Research}, volume = {86}, number = {12}, pages = {3051-3066}, doi = {10.2166/wst.2022.380}, pmid = {36579869}, issn = {0273-1223}, abstract = {The pure-MBBR process was applied to remove ammonia in a full-scale micro-polluted-water treatment plant with a daily treatment capacity of 260 × 10[4] m[3]/d, Guangdong, China. The relationship between treatment efficiency, physical and chemical properties and microbial diversity in the process of biofilm growth was explored, and the oxygen transfer model of biofilm was established. The results show that the effluent of two-stage pure MBBR process is stable and up to standard after 10 days' incubation. The nitrification loads of two-stage biofilm was stable on the 14th day. The biomass and biofilm thickness lagged behind the nitrification load, and reached a relatively stable level on the 28th day. The species richness of biofilm basically reached a stable level on the 21st day, and the microbial diversity of primary biofilm was higher. In the primary and secondary stage at different periods, the relative abundance of dominant nitrifying bacteria Nitrospira reaches 8.48-13.60%, 6.48-9.27%, and Nitrosomonas reaches 2.89-5.64%, 0.00-3.48%. The pure MBBR system mainly adopts perforated aeration. Through the cutting and blocking of bubbles by suspended carriers, the oxygen transfer rate of the system was greatly improved.}, }
@article {pmid36579711, year = {2022}, author = {Terrettaz, C and Cabete, B and Geiser, J and Valentini, M and Gonzalez, D}, title = {KaiC-like proteins contribute to stress resistance and biofilm formation in environmental Pseudomonas species.}, journal = {Environmental microbiology}, volume = {}, number = {}, pages = {}, doi = {10.1111/1462-2920.16330}, pmid = {36579711}, issn = {1462-2920}, abstract = {KaiC is the central cog of the circadian clock in Cyanobacteria. Close homologs of this protein are widespread among nonphotosynthetic bacteria, but the function, interaction network, and mechanism of action of these proteins are still largely unknown. Here, we focus on KaiC homologs found in environmental Pseudomonas species. Using bioinformatics, we describe the distribution of this protein family in the genus and reveal a conserved interaction network comprising a histidine kinase and response regulator. We characterize experimentally the only KaiC homolog present in Pseudomonas putida KT2440 and Pseudomonas protegens CHA0. Through phenotypic assays and transcriptomics, we show that KaiC is involved in osmotic and oxidative stress resistance in P. putida and in biofilm production in both species. KaiC homologs are found in different phosphorylation states and physically interact with a cognate histidine kinase and response regulator. In contrast with cyanobacterial counterparts, the expression and phosphorylation of KaiC homologs do not correlate with light variations under 12:12 light:dark cycles in either Pseudomonas species, and KaiC itself is not required to support a light-driven behavior in P. putida. Overall, this suggests that KaiC homologs in Pseudomonas species are involved in environmental stress resistance, but not specifically in responses to diurnal rhythms. This article is protected by copyright. All rights reserved.}, }
@article {pmid36577889, year = {2022}, author = {Öztürk, FY and Darcan, C and Kariptaş, E}, title = {The Determination, Monitoring, Molecular Mechanisms and Formation of Biofilm in E. coli.}, journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]}, volume = {}, number = {}, pages = {}, pmid = {36577889}, issn = {1678-4405}, abstract = {Biofilms are cell assemblies embedded in an exopolysaccharide matrix formed by microorganisms of a single or many different species. This matrix in which they are embedded protects the bacteria from external influences and antimicrobial effects. The biofilm structure that microorganisms form to protect themselves from harsh environmental conditions and survive is found in nature in many different environments. These environments where biofilm formation occurs have in common that they are in contact with fluids. The gene expression of bacteria in complex biofilm differs from that of bacteria in the planktonic state. The differences in biofilm cell expression are one of the effects of community life. Means of quorum sensing, bacteria can act in coordination with each other. At the same time, while biofilm formation provides many benefits to bacteria, it has positive and negative effects in many different areas. Depending on where they occur, biofilms can cause serious health problems, contamination risks, corrosion, and heat and efficiency losses. However, they can also be used in water treatment plants, bioremediation, and energy production with microbial fuel cells. In this review, the basic steps of biofilm formation and biofilm regulation in the model organism Escherichia coli were discussed. Finally, the methods by which biofilm formation can be detected and monitored were briefly discussed.}, }
@article {pmid36576655, year = {2022}, author = {Maity, S and Sarkar, D and Poddar, K and Patil, P and Sarkar, A}, title = {Biofilm-Mediated Heavy Metal Removal from Aqueous System by Multi-Metal-Resistant Bacterial Strain Bacillus sp. GH-s29.}, journal = {Applied biochemistry and biotechnology}, volume = {}, number = {}, pages = {}, pmid = {36576655}, issn = {1559-0291}, abstract = {Worldwide ever-augmenting urbanization, modernization, and industrialization have contributed to the release of pernicious compounds and a variety of pollutants into the environment. The pollutants discharged due to industrialization are of global concern. Industrial waste and effluent are comprised of hazardous organic and inorganic chemicals including heavy metals which pose a significant threat to the environment and may bring about numerous diseases or abnormalities in human beings. This brings on greater urgency for remediation of these polluted soil and water using sustainable approaches and mechanisms. In the present research, a multi-metal-resistant, gram-positive, non-virulent bacterial strain Bacillus sp. GH-s29 was isolated from contaminated groundwater of Bhojpur district, Bihar, India. The strain had the potential to develop a biofilm that was able to remediate different heavy metals [arsenic, cadmium, and chromium] from individual and multi-heavy metal solutions. Maximum removal for As (V), Cd (II), and Cr (VI) from individual-metal and the multi-metal solution was observed to be 73.65%, 57.37%, 61.62%, and 48.92%, 28.7%, and 35.46%, respectively. SEM-EDX analysis revealed the sequestration of multi-heavy metals by bacterial biofilm. Further characterization by FTIR analysis ensured that the presence of negatively charged functional groups on the biofilm-EPS such as hydroxyl, phosphate, sulfate, and carboxyl helps in binding to the positively charged metal ions. Thus, Bacillus sp. GH-s29 proved to be an effective and economical alternative for different heavy metal remediation from contaminated sites.}, }
@article {pmid36576565, year = {2022}, author = {Wuersching, SN and Westphal, D and Stawarczyk, B and Edelhoff, D and Kollmuss, M}, title = {Surface properties and initial bacterial biofilm growth on 3D-printed oral appliances: a comparative in vitro study.}, journal = {Clinical oral investigations}, volume = {}, number = {}, pages = {}, pmid = {36576565}, issn = {1436-3771}, abstract = {OBJECTIVES: To investigate the initial bacterial adhesion on 3D-printed splint materials in relation to their surface properties.<br><br>MATERIALS AND METHODS: Specimens of five printable splint resins (SHERAprint-ortho plus UV, NextDent Ortho Rigid, LuxaPrint Ortho Plus, V-Print Splint, KeySplint Soft), one polymethylmethacrylate (PMMA) block for subtractive manufacturing (Astron CLEARsplint Disc), two conventional powder/liquid PMMA materials (FuturaGen, Astron CLEARsplint), and one polyethylene terephthalate glycol (PETG) thermoplastic sheet for vacuum forming (Erkodur Thermoforming Foil) were produced and finished. Surface roughness Ra was determined via contact profilometry. Surface morphology was examined under a scanning electron microscope. Multi-species bacterial biofilms were grown on entire splints. Total biofilm mass and viable bacterial counts (CFU/ml) within the biofilms were determined. Statistical analyses were performed with a one-way ANOVA, Tukey's post hoc test, and Pearson's test (p&#x2009;<&#x2009;0.05).<br><br>RESULTS: Astron CLEARsplint and KeySplint Soft specimens showed the highest surface roughness. The mean total biofilm mass on KeySplint Soft splints was higher compared to all other materials (p&#x2009;<&#x2009;0.05). Colony-forming unit per milliliter on FuturaGen, Astron CLEARsplint, and KeySplint Soft splints was one log scale higher compared to all other materials. The other four printable resins displayed overall lower Ra, biofilm mass, and CFU/ml. A positive correlation was found between Ra and CFU/ml (r&#x2009;=&#x2009;0.69, p&#x2009;=&#x2009;0.04).<br><br>CONCLUSIONS: The 3D-printed splints showed overall favorable results regarding surface roughness and bacterial adhesion. Thermoplastic materials seem to display a higher surface roughness, making them more susceptible to microbial adhesion.<br><br>CLINICAL RELEVANCE: The development of caries and gingivitis in patients with oral appliances may be affected by the type of material.}, }
@article {pmid36575632, year = {2022}, author = {Pouget, C and Pantel, A and Dunyach-Remy, C and Magnan, C and Sotto, A and Lavigne, JP}, title = {Antimicrobial activity of antibiotics on biofilm formed by Staphylococcus aureus and Pseudomonas aeruginosa in an open microfluidic model mimicking the diabetic foot environment.}, journal = {The Journal of antimicrobial chemotherapy}, volume = {}, number = {}, pages = {}, doi = {10.1093/jac/dkac438}, pmid = {36575632}, issn = {1460-2091}, abstract = {BACKGROUND: Diabetic foot infections (DFIs) represent a public health problem because of their frequency and the severity of their consequences, i.e. amputation and mortality. Polymicrobial biofilms on the skin surface of these ulcers complicate wound healing. Few in vitro models exist to study the antibiotics activity in this context.<br><br>OBJECTIVES: This study evaluated the in vitro activity of antibiotics against the two main bacteria isolated in DFI, Staphylococcus aureus and Pseudomonas aeruginosa, using a dynamic system (BioFlux&#x2122; 200) and a chronic wound-like medium (CWM) that mimic the foot ulcer environment.<br><br>METHODS: Reference strains and two pairs of clinical S. aureus and P. aeruginosa isolated together from a DFI were cultivated in brain heart infusion and CWM media during 72&#x2005;h at 37&#xb0;C, alone and combined in the BioFlux&#x2122; 200 system. Antibiotic activity was evaluated after a mechanical debridement. The activities were measured by the reduction of biofilm percentage of bacteria in the microfluidic system using microscopy.<br><br>RESULTS: Daptomycin for S. aureus and ceftazidime for P. aeruginosa showed excellent activity to reduce biofilm biomass, whereas linezolid action was more mitigated and dalbavancin was ineffective. Ceftazidime&#x200a;+&#x200a;daptomycin presented the most potent in vitro activity on a mixed biofilm.<br><br>CONCLUSIONS: The combination of CWM and the BioFlux&#x2122; microfluidic system represents a valuable tool to screen the potential antimicrobial activity of antibiotics under conditions mimicking those encountered in DFI. It could help clinicians in their management of chronic wounds.}, }
@article {pmid36575298, year = {2022}, author = {Maldiney, T and Pineau, V and Neuwirth, C and Ouzen, L and Eberl, I and Jeudy, G and Dalac, S and Piroth, L and Blot, M and Sautour, M and Dalle, F and Abdulmalak, C and Ter Schiphorst, R and Pugliesi, PS and Poussant, T and Ogier-Desserrey, A and Fournel, I and de Giraud d'Agay, M and Jacquier, M and Labruyère, M and Aptel, F and Roudaut, JB and Vieille, T and Andreu, P and Prin, S and Charles, PE and Hamet, M and Quenot, JP}, title = {Endotracheal tube biofilm in critically ill patients during the COVID-19 pandemic : description of an underestimated microbiological compartment.}, journal = {Scientific reports}, volume = {12}, number = {1}, pages = {22389}, pmid = {36575298}, issn = {2045-2322}, abstract = {Biofilm (BF) growth is believed to play a major role in the development of ventilator-associated pneumonia (VAP) in the intensive care unit. Despite concerted efforts to understand the potential implication of endotracheal tube (ETT)-BF dispersal, clinically relevant data are lacking to better characterize the impact of its mesostructure and microbiological singularity on the occurrence of VAP. We conducted a multicenter, retrospective observational study during the third wave of the COVID-19 pandemic, between March and May 2021. In total, 64 ETTs collected from 61 patients were included in the present BIOPAVIR study. Confocal microscopy acquisitions revealed two main morphological aspects of ETT-deposited BF: (1) a thin, continuous ribbon-shaped aspect, less likely monobacterial and predominantly associated with Enterobacter spp., Streptococcus pneumoniae or Viridans streptococci, and (2) a thicker, discontinuous, mushroom-shaped appearance, more likely characterized by the association of bacterial and fungal species in respiratory samples. The microbiological characterization of ETT-deposited BF found higher acquired resistance in more than 80% of analyzed BF phenotypes, compared to other colonization sites from the patient's environment. These findings reveal BF as a singular microbiological compartment, and are of added clinical value, with a view to future ETT-deposited BF-based antimicrobial stewardship in critically ill patients. Trial registration NCT04926493. Retrospectively registered 15 June 2021.}, }
@article {pmid36574888, year = {2022}, author = {Liu, Q and Hou, J and Zeng, Y and Xia, J and Miao, L and Wu, J}, title = {Integrated photocatalysis and moving bed biofilm reactor (MBBR) for treating conventional and emerging organic pollutants from synthetic wastewater: performances and microbial community responses.}, journal = {Bioresource technology}, volume = {}, number = {}, pages = {128530}, doi = {10.1016/j.biortech.2022.128530}, pmid = {36574888}, issn = {1873-2976}, abstract = {Increasing concern for emerging organic pollutants (e.g. antibiotics) urges improvements in conventional biological wastewater treatment processes. This study examined the performance of an integrated photocatalysis and moving bed biofilm reactor (MBBR) system in treating synthetic wastewater containing sulfamethoxazole (SMX). It was found that the integrated system could remove over 80.5% of SMX and 67.7%-80.7% of chemical oxygen demand (COD) with a hydraulic retention time of 24 h. The introduction of photocatalysis had no impact on COD removal and significantly enhanced SMX removal. High-throughput analysis indicated that microbial community greatly altered due to photocatalytic oxidation stress, with clostridiaceae and enterobacteriaceae becoming dominant families. Nevertheless, microorganisms maintained metabolic activity, which may be ascribed to the protection of carriers and microbial self-preservation by secreting extracellular polymeric substances and antioxidant enzymes. Collectively, this study sheds light on treating wastewater containing conventional and emerging organic pollutants by integrating photocatalysis with MBBR.}, }
@article {pmid36573013, year = {2022}, author = {Khoshnood, S and Sadeghifard, N and Mahdian, N and Heidary, M and Mahdian, S and Mohammadi, M and Maleki, A and Haddadi, MH}, title = {Antimicrobial resistance and biofilm formation capacity among Acinetobacter baumannii strains isolated from patients with burns and ventilator-associated pneumonia.}, journal = {Journal of clinical laboratory analysis}, volume = {}, number = {}, pages = {e24814}, doi = {10.1002/jcla.24814}, pmid = {36573013}, issn = {1098-2825}, abstract = {BACKGROUND: Acinetobacter baumannii is a pathogen responsible for nosocomial infections, especially in patients with burns and ventilator-associated pneumonia (VAP). The aims of this study was to compare the biofilm formation capacity, antimicrobial resistance patterns and molecular typing based on PFGE (Pulsed-Field Gel Electrophoresis) in A. baumannii isolated from burn and VAP patients.<br><br>MATERIALS AND METHODS: A total of 50 A.&#xa0;baumannii isolates were obtained from burn and VAP patients. In this study, we assessed antimicrobial susceptibility, biofilm formation capacity, PFGE fingerprinting, and the distribution of biofilm-related genes (csuD, csuE, ptk, ataA, and ompA).<br><br>RESULTS: Overall, 74% of the strains were multidrug resistant (MDR), and 26% were extensively drug-resistant (XDR). Regarding biofilm formation capacity, 52%, 36%, and 12% of the isolates were strong, moderate, and weak biofilm producers. Strong biofilm formation capacity significantly correlated with XDR phenotype (12/13, 92.3%). All the isolates harbored at least one biofilm-related gene. The most prevalent gene was csuD (98%), followed by ptk (90%), ataA (88%), ompA (86%), and csuE (86%). Harboring all the biofilm-related genes was significantly associated with XDR phenotype. Finally, PFGE clustering revealed 6 clusters, among which cluster No. 2 showed a significant correlation with strong biofilm formation and XDR phenotype.<br><br>CONCLUSION: Our findings revealed the variable distribution of biofilm-related genes among MDR and XDR A.&#xa0;baumannii isolates from burn and VAP patients. A significant correlation was found between strong biofilm formation capacity and XDR phenotype. Finally, our results suggested that XDR phenotype was predominant among strong-biofilm producer A.&#xa0;baumannii in our region.}, }
@article {pmid36572871, year = {2022}, author = {Tashakkori, N and Rahmani, HK and Khoramian, B}, title = {Genotypic and phenotypic diversity of Prototheca spp. recovered from bovine mastitis in terms of antimicrobial resistance and biofilm formation ability.}, journal = {BMC veterinary research}, volume = {18}, number = {1}, pages = {452}, pmid = {36572871}, issn = {1746-6148}, abstract = {BACKGROUND: The Prototheca algae have recently emerged as an important cause of bovine mastitis globally. Isolates from bovine mastitis in several countries were nearly all identified as P. bovis, suggesting that it was the main causative agent of bovine protothecal mastitis. The aim of the present study was to evaluate the presence and isolation of Prototheca spp. in dairy farms, detect the genetic diversity among strains, determine the capacity of producing biofilm and their resistance to antifungal and antimicrobial drugs.<br><br>RESULTS: A total of 48 Prototheca isolates from four different farms were randomly selected to be investigated. Multiplex PCR showed all isolated colonies were Prototheca bovis. Performing RAPD-PCR by using OPA-4 primer, it was revealed that there was a clear amplification pattern. Different levels of biofilm production were observed among strains. Among 48 isolates, only 4 of them (8.33%) showed strong biofilm production. By using E-test strips, amphotericin B was able to inhibit the growth of all the strains tested. Disc diffusion method used for antimicrobial sensitivity test showed that the highest activity was demonstrated by gentamicin and colistin with 95.83% (46/48) and 89.58% (43/48) of sensitive strains, respectively.<br><br>CONCLUSIONS: The present study showed that RAPD-PCR was a rapid tool for discriminating P. bovis strains. Also, gentamicin and colistin can be considered as potential antimicrobial drugs which can prevent the growth of the mentioned strains in vitro, although there is no effective clinical treatment yet. Further studies are needed in order to detect an effective clinical therapy considering biofilm production by Prototheca spp. and their probable role in Prototheca pathogenicity.}, }
@article {pmid36570317, year = {2022}, author = {Sahoo, J and Sarkhel, S and Mukherjee, N and Jaiswal, A}, title = {Nanomaterial-Based Antimicrobial Coating for Biomedical Implants: New Age Solution for Biofilm-Associated Infections.}, journal = {ACS omega}, volume = {7}, number = {50}, pages = {45962-45980}, pmid = {36570317}, issn = {2470-1343}, abstract = {Recently, the upsurge in hospital-acquired diseases has put global health at risk. Biomedical implants being the primary source of contamination, the development of biomedical implants with antimicrobial coatings has attracted the attention of a large group of researchers from around the globe. Bacteria develops biofilms on the surface of implants, making it challenging to eradicate them with the standard approach of administering antibiotics. A further issue of current concern is the fast resurgence of resistance to conventional antibiotics. As nanotechnology continues to advance, various types of nanomaterials have been created, including 2D nanoparticles and metal and metal oxide nanoparticles with antimicrobial properties. Researchers from all over the world are using these materials as a coating agent for biomedical implants to create an antimicrobial environment. This comprehensive and contemporary review summarizes various metals, metal oxide nanoparticles, 2D nanomaterials, and their composites that have been used or may be used in the future as an antimicrobial coating agent for biomedical implants, as well as their succinct mode of action to combat biofilm-associated infection and diseases.}, }
@article {pmid36569981, year = {2022}, author = {Vyas, HKN and Xia, B and Mai-Prochnow, A}, title = {Clinically relevant in vitro biofilm models: A need to mimic and recapitulate the host environment.}, journal = {Biofilm}, volume = {4}, number = {}, pages = {100069}, pmid = {36569981}, issn = {2590-2075}, abstract = {Biofilm-associated infections are difficult to treat and eradicate because of their increased antimicrobial tolerance. In vitro biofilm models have enabled the high throughput testing of an array of differing novel antimicrobials and treatment strategies. However, biofilms formed in these oftentimes basic in vitro systems do not resemble biofilms seen in vivo. As a result, translatability from the lab to the clinic is poor or limited. To improve translatability, in vitro models must better recapitulate the host environment. This review describes and critically evaluates new and innovative in vitro models that better mimic the environments of a variety of clinically important, biofilm-associated infections of the skin, oropharynx, lungs, and infections related to indwelling implants and medical devices. This review highlights that many of these models represent considerable advances in the field of biofilm research and help to translate laboratory findings into the clinical practice.}, }
@article {pmid36567396, year = {2022}, author = {Odame, F and Neglo, D and Sedohia, D and Arthur, R}, title = {Antifungal synergistic effects and anti-biofilm formation activities of some bioactive 2,3-dihydro-1,5-benzoxazepine derivatives.}, journal = {Archives of microbiology}, volume = {205}, number = {1}, pages = {39}, pmid = {36567396}, issn = {1432-072X}, abstract = {Benzoxazepines constitute a significant class of organic compounds extensively described in the literature. Several derivatives with pharmacological properties have been produced due to the semi-rigid azepine scaffold, which allows for the addition of other heteroatoms. This study investigated the possible antifungal effect and antioxidant activity of 2,3-dihydro-1,5-benzoxazepines. The antifungal effect was investigated using the broth dilution assay, while the antioxidant property was determined using the ABTS and DPPH scavenging tests. The results indicated that the 2,3-dihydro-1,5-benzoxazepine derivatives had antifungal properties and could be working via its fungicidal and biofilm inhibitory properties. It was also realized that it had synergistic effects when administered concomitantly with standard antifun