@article {pmid35777514,
year = {2022},
author = {Ge, Z and Chen, X and Yang, R and Li, W and Yin, B and Li, Z and Dong, M},
title = {Structure of a unique fucose-containing exopolysaccharide from Sayram ketteki yoghurt and its anti-MRSA biofilm effect.},
journal = {International journal of biological macromolecules},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.ijbiomac.2022.06.164},
pmid = {35777514},
issn = {1879-0003},
abstract = {In this work, we reported an in situ exopolysaccharide (in situ-EPS1) containing rare fucose produced by Lactobacillus helveticus MB2-1in Sayram ketteki yoghurt, which made it unique. Its fine structure was characterized by GPC, HPLC, FT-IR, GC-MS,1HNMR and 13CNMR together with two-dimensional (2D) NMR spectra. The results revealed that in situ-EPS1 was a new heteropolysaccharide with molecular weight of 1.06 × 105 Da, and was composed of mannose, rhamnose, glucose, galactose and fucose with the following repeating units. Furthermore, the in situ-EPS1 exhibited significant antibiofilm effect against Methicillin-resistant Staphylococcus aureus (MRSA). Notably, the in situ-EPS1 did not interfere with the planktonic growth of MRSA strain, whereas inhibited its cell metabolic activity and the transcription of genes related to biofilm formation. This unique antibiofilm but non-antibacterial mechanism supposedly prevented the development of bacterial drug resistance, which may open a new door to fight against these drug-resistant microorganisms.},
}
@article {pmid35777467,
year = {2022},
author = {Yarawsky, AE and Hopkins, JB and Chatzimagas, L and Hub, JS and Herr, AB},
title = {Solution structural studies of pre-amyloid oligomer states of the biofilm protein Aap.},
journal = {Journal of molecular biology},
volume = {},
number = {},
pages = {167708},
doi = {10.1016/j.jmb.2022.167708},
pmid = {35777467},
issn = {1089-8638},
abstract = {Staphylococcus epidermidis is a commensal bacterium on human skin that is also the leading cause of medical device-related infections. The accumulation-associated protein (Aap) from S. epidermidis is a critical factor for infection via its ability to mediate biofilm formation. The B-repeat superdomain of Aap is composed of 5 to 17 Zn2+-binding B-repeats, which undergo rapid, reversible assembly to form dimer and tetramer species. The tetramer can then undergo a conformational change and nucleate highly stable functional amyloid-like fibrils. In this study, multiple techniques including analytical ultracentrifugation (AUC) and small-angle X-ray scattering (SAXS) are used to probe a panel of B-repeat mutant constructs that assemble to distinct oligomeric states to define the structural characteristics of B-repeat dimer and tetramer species. The B-repeat region from Aap forms an extremely elongated conformation that presents several challenges for standard SAXS analyses. Specialized approaches, such as cross-sectional analyses, allowed for in-depth interpretation of data, while explicit-solvent calculations via WAXSiS allowed for accurate evaluation of atomistic models. The resulting models suggest mechanisms by which Aap functional amyloid fibrils form, illuminating an important contributing factor to recurrent staphylococcal infections.},
}
@article {pmid35777177,
year = {2022},
author = {Besser, M and Schaeler, L and Plattfaut, I and Brill, FHH and Kampe, A and Geffken, M and Smeets, R and Debus, ES and Stuermer, EK},
title = {Pulsed low-intensity laser treatment stimulates wound healing without enhancing biofilm development in vitro.},
journal = {Journal of photochemistry and photobiology. B, Biology},
volume = {233},
number = {},
pages = {112504},
doi = {10.1016/j.jphotobiol.2022.112504},
pmid = {35777177},
issn = {1873-2682},
abstract = {OBJECTIVES: Treating infected or chronic wounds burdened with biofilms still is a major challenge in medical care. Healing-stimulating factors lose their efficacy due to bacterial degradation, and antimicrobial substances negatively affect dermal cells. Therefore, alternative treatment approaches like the pulsed low intensity laser therapy (LILT) require consideration.<br><br>METHODS: The effect of pulsed LILT (904 nm, in three frequencies) on relevant human cells of the wound healing process (fibroblasts (BJ), keratinocytes (HaCaT), endothelial cells (HMEC), monocytes (THP-1)) were investigated in in-vitro and ex-vivo wound models with respect to viability, proliferation and migration. Antimicrobial efficacy of the most efficient frequency in cell biological analyses of LILT (3200 Hz) was determined in a human biofilm model (lhBIOM). Quantification of bacterial load was evaluated by suspension method and qualitative visualization was performed by scanning electron microscopy (SEM).<br><br>RESULTS: Pulsed LILT at 904 nm at 3200 Hz ± 50% showed the most positive effects on metabolic activity and proliferation of human wound cells in vitro (after 72 h - BJ: BPT 0.97 ± 0.05 vs. 0.75 ± 0.04 (p = 0.0283); HaCaT: BPT 0.79 ± 0.04 vs. 0.59 ± 0.02 (p = 0.0106); HMEC: 0.74 ± 0.02 vs. 0.52 ± 0.04 (p = 0.009); THP-1: 0.58 ± 0.01 vs. 0.64 ± 0.01 (p > 0.05) and ex vivo. Interestingly, re-epithelialization was stimulated in a frequency-independent manner. The inhibition of metabolic activity after TNF-α application was abolished after laser treatment. No impact of LILT on monocytes was detected. Likewise, the tested LILT regimens showed no growth rate reducing effects on three bacterial strains (after 72 h - PA: -1.03%; SA: -0.02%; EF: -1,89%) and one fungal (-2.06%) biofilm producing species compared to the respective untreated control. Accordingly, no significant morphological changes of the biofilms were observed after LILT treatment in the SEM.<br><br>CONCLUSIONS: Frequent application of LILT (904 nm, 3200 Hz) seems to be beneficial for the metabolism of human dermal cells during wound healing. Considering this, the lack of disturbance of the behavior of the immune cells and no growth-inducing effect on bacteria and fungi in the biofilm can be assigned as rather positive. Based on this combined mode of action, LILT may be an option for hard to heal wounds infected with persistent biofilms.},
}
@article {pmid35776759,
year = {2022},
author = {Moshynets, OV and Baranovskyi, TP and Cameron, S and Iungin, OS and Pokholenko, I and Jerdan, R and Kamyshnyi, A and Krikunov, AA and Potochilova, VV and Rudnieva, KL and Spiers, AJ},
title = {Azithromycin possesses biofilm-inhibitory activity and potentiates non-bactericidal colistin methanesulfonate (CMS) and polymyxin B against Klebsiella pneumonia.},
journal = {PloS one},
volume = {17},
number = {7},
pages = {e0270983},
doi = {10.1371/journal.pone.0270983},
pmid = {35776759},
issn = {1932-6203},
abstract = {Novel antibiotic combinations may act synergistically to inhibit the growth of multidrug-resistant bacterial pathogens but predicting which combination will be successful is difficult, and standard antimicrobial susceptibility testing may not identify important physiological differences between planktonic free-swimming and biofilm-protected surface-attached sessile cells. Using a nominally macrolide-resistant model Klebsiella pneumoniae strain (ATCC 10031) we demonstrate the effectiveness of several macrolides in inhibiting biofilm growth in multi-well plates, and the ability of azithromycin (AZM) to improve the effectiveness of the antibacterial last-agent-of-choice for K. pneumoniae infections, colistin methanesulfonate (CMS), against biofilms. This synergistic action was also seen in biofilm tests of several K. pneumoniae hospital isolates and could also be identified in polymyxin B disc-diffusion assays on azithromycin plates. Our work highlights the complexity of antimicrobial-resistance in bacterial pathogens and the need to test antibiotics with biofilm models where potential synergies might provide new therapeutic opportunities not seen in liquid culture or colony-based assays.},
}
@article {pmid35775548,
year = {2022},
author = {Sharma, A and Vashistt, J and Shrivastava, R},
title = {Knockdown of the Type-II Fatty acid synthase gene hadC in mycobacterium fortuitum does not affect its growth, biofilm formation, and survival under stress.},
journal = {International journal of mycobacteriology},
volume = {11},
number = {2},
pages = {159-166},
doi = {10.4103/ijmy.ijmy_46_22},
pmid = {35775548},
issn = {2212-554X},
abstract = {Background: Mycobacterial fatty acid synthase Type-II (FAS-II) components are major virulence factors exploited as potential targets for developing novel antimycobacterial drugs. The FAS-II enzyme 3-hydroxyacyl-ACP dehydratase (HadC) is important for biofilm development and pathogenesis of Mycobacterium tuberculosis and other mycobacterial species.<br><br>Methods: Literature review and homology search led to the identification of Mycobacterium fortuitum MFhadC gene. Functional interaction study of MFHadC protein was done using STRING. M. fortuitum MFhadC over-expressing (HS) and knockdown (HA) strains were constructed and validated by expression analysis using quantitative polymerase chain reaction. The strains were analyzed for growth behavior and surface spreading ability. Biofilm formation was assayed through crystal violet assay, viability count, and basic fuchsin staining. In addition, survival of the strains was studied under in vitro nutrient starvation and detergent stress.<br><br>Results: STRING analysis showed the interaction of HadC with proteins involved in biofilm formation. The strains HS and HA showed spreading ability on the agarose surface, exhibiting translocation patterns similar to the vector control strain. All three strains showed a similar amount of biofilm formation when analyzed using crystal violet assay, viability count, and basic fuchsin staining. The strains showed no deviation in survival when incubated under nutrient starvation and detergent stress.<br><br>Conclusion: Our results suggest that MFhadC may not be important for the formation and maintenance of biofilm, a factor critically important in M. fortuitum pathogenicity. However, not essential for survival and growth, MFhadC maintains the viability of M. fortuitum under a nutrient-starved environment. Collectively, MFhadC may not be used as a biofilm-specific marker for M. fortuitum.},
}
@article {pmid35774452,
year = {2022},
author = {Tao, Q and Wu, Q and Zhang, Z and Liu, J and Tian, C and Huang, Z and Malakar, PK and Pan, Y and Zhao, Y},
title = {Meta-Analysis for the Global Prevalence of Foodborne Pathogens Exhibiting Antibiotic Resistance and Biofilm Formation.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {906490},
doi = {10.3389/fmicb.2022.906490},
pmid = {35774452},
issn = {1664-302X},
abstract = {Antimicrobial-resistant (AMR) foodborne bacteria causing bacterial infections pose a serious threat to human health. In addition, the ability of some of these bacteria to form biofilms increases the threat level as treatment options may become compromised. The extent of antibiotic resistance and biofilm formation among foodborne pathogens remain uncertain globally due to the lack of systematic reviews. We performed a meta-analysis on the global prevalence of foodborne pathogens exhibiting antibiotic resistance and biofilm formation using the methodology of a Cochrane review by accessing data from the China National Knowledge Infrastructure (CNKI), PubMed, and Web of Science databases between 2010 and 2020. A random effects model of dichotomous variables consisting of antibiotic class, sample source, and foodborne pathogens was completed using data from 332 studies in 36 countries. The results indicated AMR foodborne pathogens has become a worrisome global issue. The prevalence of AMR foodborne pathogens in food samples was greater than 10% and these foodborne pathogens were most resistant to β-lactamase antibiotics with Bacillus cereus being most resistant (94%). The prevalence of AMR foodborne pathogens in human clinical specimens was greater than 19%, and the resistance of these pathogens to the antibiotic class used in this research was high. Independently, the overall biofilm formation rate of foodborne pathogenic bacteria was 90% (95% CI, 68%-96%) and a direct linear relationship between biofilm formation ability and antibiotic resistance was not established. Future investigations should document both AMR and biofilm formation of the foodborne pathogen isolated in samples. The additional information could lead to alternative strategies to reduce the burden cause by AMR foodborne pathogens.},
}
@article {pmid35774451,
year = {2022},
author = {Wu, S and Wu, B and Liu, Y and Deng, S and Lei, L and Zhang, H},
title = {Mini Review Therapeutic Strategies Targeting for Biofilm and Bone Infections.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {936285},
doi = {10.3389/fmicb.2022.936285},
pmid = {35774451},
issn = {1664-302X},
abstract = {Bone infection results in a complex inflammatory response and bone destruction. A broad spectrum of bacterial species has been involved for jaw osteomyelitis, hematogenous osteomyelitis, vertebral osteomyelitis or diabetes mellitus, such as Staphylococcus aureus (S. aureus), coagulase-negative Staphylococcus species, and aerobic gram-negative bacilli. S. aureus is the major pathogenic bacterium for osteomyelitis, which results in a complex inflammatory response and bone destruction. Although various antibiotics have been applied for bone infection, the emergence of drug resistance and biofilm formation significantly decrease the effectiveness of those agents. In combination with gram-positive aerobes, gram-negative aerobes and anaerobes functionally equivalent pathogroups interact synergistically, developing as pathogenic biofilms and causing recurrent infections. The adhesion of biofilms to bone promotes bone destruction and protects bacteria from antimicrobial agent stress and host immune system infiltration. Moreover, bone is characterized by low permeability and reduced blood flow, further hindering the therapeutic effect for bone infections. To minimize systemic toxicity and enhance antibacterial effectiveness, therapeutic strategies targeting on biofilm and bone infection can serve as a promising modality. Herein, we focus on biofilm and bone infection eradication with targeting therapeutic strategies. We summarize recent targeting moieties on biofilm and bone infection with peptide-, nucleic acid-, bacteriophage-, CaP- and turnover homeostasis-based strategies. The antibacterial and antibiofilm mechanisms of those therapeutic strategies include increasing antibacterial agents' accumulation by bone specific affinity, specific recognition of phage-bacteria, inhibition biofilm formation in transcription level. As chronic inflammation induced by infection can trigger osteoclast activation and inhibit osteoblast functioning, we additionally expand the potential applications of turnover homeostasis-based therapeutic strategies on biofilm or infection related immunity homeostasis for host-bacteria. Based on this review, we expect to provide useful insights of targeting therapeutic efficacy for biofilm and bone infection eradication.},
}
@article {pmid35771939,
year = {2022},
author = {Tai, JB and Mukherjee, S and Nero, T and Olson, R and Tithof, J and Nadell, CD and Yan, J},
title = {Social evolution of shared biofilm matrix components.},
journal = {Proceedings of the National Academy of Sciences of the United States of America},
volume = {119},
number = {27},
pages = {e2123469119},
doi = {10.1073/pnas.2123469119},
pmid = {35771939},
issn = {1091-6490},
support = {N/A//Burroughs Wellcome Fund (BWF)/ ; 1015763.02//Burroughs Wellcome Fund (BWF)/ ; 826672//Simons Foundation (SF)/ ; DRG-2446-21//Damon Runyon Cancer Research Foundation (DRCRF)/ ; DP2GM146253//HHS | NIH | National Institute of General Medical Sciences (NIGMS)/ ; },
abstract = {Biofilm formation is an important and ubiquitous mode of growth among bacteria. Central to the evolutionary advantage of biofilm formation is cell-cell and cell-surface adhesion achieved by a variety of factors, some of which are diffusible compounds that may operate as classical public goods-factors that are costly to produce but may benefit other cells. An outstanding question is how diffusible matrix production, in general, can be stable over evolutionary timescales. In this work, using Vibrio cholerae as a model, we show that shared diffusible biofilm matrix proteins are indeed susceptible to cheater exploitation and that the evolutionary stability of producing these matrix components fundamentally depends on biofilm spatial structure, intrinsic sharing mechanisms of these components, and flow conditions in the environment. We further show that exploitation of diffusible adhesion proteins is localized within a well-defined spatial range around cell clusters that produce them. Based on this exploitation range and the spatial distribution of cell clusters, we constructed a model of costly diffusible matrix production and related these length scales to the relatedness coefficient in social evolution theory. Our results show that production of diffusible biofilm matrix components is evolutionarily stable under conditions consistent with natural biofilm habitats and host environments. We expect the mechanisms revealed in this study to be relevant to other secreted factors that operate as cooperative public goods in bacterial communities and the concept of exploitation range and the associated analysis tools to be generally applicable.},
}
@article {pmid35771053,
year = {2022},
author = {Kamei, T and Rujakom, S and Nakano, M and Maharjan, AK and Kazama, F},
title = {Investigation of nitrite accumulation by hydrogenotrophic denitrification in a moving bed biofilm reactor for partial denitrification and anammox process.},
journal = {Water science and technology : a journal of the International Association on Water Pollution Research},
volume = {85},
number = {12},
pages = {3396-3407},
doi = {10.2166/wst.2022.187},
pmid = {35771053},
issn = {0273-1223},
abstract = {The partial denitrification and anammox (PDA) process has received attention for its ability to optimize treatment of wastewater containing a low NH4+-N concentration. This study investigated the suitable operational conditions for NO2--N accumulation by hydrogenotrophic denitrification (HD) in operation of a laboratory-scale moving bed biofilm reactor, for future application in the PDA process. NO2--N accumulation was achieved by minimizing the H2 flow rate under optimized conditions (i.e., 15 mL/min H2 flow rate, 40 mg-N/L influent NO3--N, 7.0 h hydraulic retention time, and 2 L working volume). Hydrogenophaga comprised 39.2% of the bacterial abundance after NO2--N accumulated, indicating its contribution to the NO2--N accumulation. In addition, an intermittent H2 supply maintained the NO2--N accumulation rate (NAR) and maximized the nitrite accumulation efficiency (NAE). A H2 supply ratio of 0.7 (i.e., ON: 7 min, OFF: 3 min) was optimal, which induced increases in NAR, NAE, and the NO3--N removal efficiency that reached 0.07±0.01 kg-N/m3/d, 64.4±14.5%, and 89.2±8.9%, respectively. The ratio of H2 supply rate to the NO3--N loading rate was calculated as 4.3 in this experiment, which may represent the optimal balance for maximization of NO2--N accumulation by HD.},
}
@article {pmid35770177,
year = {2022},
author = {Niboucha, N and Goetz, C and Sanschagrin, L and Fontenille, J and Fliss, I and Labrie, S and Jean, J},
title = {Comparative Study of Different Sampling Methods of Biofilm Formed on Stainless-Steel Surfaces in a CDC Biofilm Reactor.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {892181},
doi = {10.3389/fmicb.2022.892181},
pmid = {35770177},
issn = {1664-302X},
abstract = {The formation of biofilms in dairy processing plants can reduce equipment efficiency, contribute to surface deterioration, and contaminate dairy products by releasing the microorganisms they contain, which may cause spoilage or disease. However, a more representative identification of microbial communities and physico-chemical characterization requires to detach and recover adequately the entire biofilm from the surface. The aim of this study is to develop an efficient technique for in-plant biofilm sampling by growing a strain of Pseudomonas azotoformans PFl1A on stainless-steel surface in a dynamic CDC biofilm reactor system using tryptic soy broth (TSB) and milk as growth media. Different techniques, namely, swabbing, scraping, sonic brushing, synthetic sponge, and sonicating synthetic sponge were used and the results were compared to a standard ASTM International method using ultrasonication. Their efficiencies were evaluated by cells enumeration and scanning electron microscopy. The maximum total viable counts of 8.65 ± 0.06, 8.75 ± 0.08, and 8.71 ± 0.09 log CFU/cm2 were obtained in TSB medium using scraping, synthetic sponge, and sonicating synthetic sponge, respectively, which showed no statistically significant differences with the standard method, ultrasonication (8.74 ± 0.02 log CFU/cm2). However, a significantly (p < 0.05) lower cell recovery of 8.57 ± 0.10 and 8.60 ± 0.00 log CFU/cm2 compared to ultrasonication were achieved for swabbing and sonic brushing, respectively. Furthermore, scanning electron microscopy showed an effective removal of biofilms by sonic brushing, synthetic sponge, and sonicating synthetic sponge; However, only the latter two methods guaranteed a superior release of bacterial biofilm into suspension. Nevertheless, a combination of sonication and synthetic sponge ensured dislodging of sessile cells from surface crevices. The results suggest that a sonicating synthetic sponge could be a promising method for biofilm recovery in processing plants, which can be practically used in the dairy industries as an alternative to ultrasonication.},
}
@article {pmid35769516,
year = {2022},
author = {Dong, H and Yang, K and Zhang, Y and Li, Q and Xiu, W and Ding, M and Shan, J and Mou, Y},
title = {Photocatalytic Cu2WS4 Nanocrystals for Efficient Bacterial Killing and Biofilm Disruption.},
journal = {International journal of nanomedicine},
volume = {17},
number = {},
pages = {2735-2750},
doi = {10.2147/IJN.S360246},
pmid = {35769516},
issn = {1178-2013},
abstract = {Background: Bacterial biofilm-related wound infections threaten human health due to the lack of efficient treatments. Therefore, developing a novel strategy for wound infection care is urgently needed.<br><br>Methods: Cube-shaped Cu2WS4 nanocrystals (CWSNs) were successfully prepared via a microwave-assisted method. CWSNs, as photocatalysts, were first studied by using fluorescence spectroscopy for their ability to generate reactive oxygen species (ROS). The antibacterial and biofilm inhibition abilities of CWSNs were determined in vitro by using Staphylococcus aureus (S. aureus) as the model bacterium. Moreover, a CWSN gel was prepared and applied to treat S. aureus-infected wounds in mice. The toxicity of the CWSNs was evaluated through in vitro cell and in vivo animal experiments.<br><br>Results: Studies on the properties of the CWSNs demonstrated that these nanomaterials can catalyze the generation of hydroxyl radicals (•OH) without the addition of H2O2 after visible-light irradiation, indicating their photocatalytic ability. Moreover, the in vitro experimental results showed that the CWSNs not only adhered to the surfaces of S. aureus to kill the bacteria, but also inhibited S. aureus biofilm formation. The in vivo study showed that the CWSN gel produced excellent antibacterial effects against S. aureus infected wounds in mice and effectively promoted wound healing. Furthermore, toxicity tests showed that the CWSNs have negligible toxicity in vitro and in vivo.<br><br>Conclusion: This work provides a potential photocatalytic antibacterial nanoagent for efficient bacterial killing, inhibition of biofilms growth and wound infection treatment.},
}
@article {pmid35769322,
year = {2022},
author = {Jiang, L and Jiang, Y and Liu, W and Zheng, R and Li, C},
title = {Characterization of the Lytic Phage Flora With a Broad Host Range Against Multidrug-Resistant Escherichia coli and Evaluation of Its Efficacy Against E. coli Biofilm Formation.},
journal = {Frontiers in veterinary science},
volume = {9},
number = {},
pages = {906973},
doi = {10.3389/fvets.2022.906973},
pmid = {35769322},
issn = {2297-1769},
abstract = {Escherichia coli is a gram-negative bacterium that is distributed widely throughout the world; it is mainly found in contaminated food, the poultry industry, and animal feces. The emergence of antibiotic-resistant E. coli poses a threat to human and animal health, which has led to renewed interest in phage-based therapy. E. coli biofilm control and prevention are of great importance. In this study, the isolated phages Flora and KM18 were found to belong to the family Myoviridae; the optimal preservation buffer was pH = 6~7, and the phage genome sizes were 168,909 (Flora) and 168,903 (KM18) bp. Phage Flora had a broader lytic spectrum than KM18. Phage Flora had a better antibiofilm effect than kanamycin sulfate in high-concentration E. coli cultures. A combination of the phage Flora and kanamycin sulfate showed better antibiofilm effects than Flora or kanamycin sulfate alone in low-concentration E. coli cultures. These characteristics can serve as a guideline for the selection of effective candidates for phage therapy, in this case antibiotic-resistant E. coli control in the poultry industry.},
}
@article {pmid35767197,
year = {2022},
author = {Chen, H and Wu, L and Su, Y and Huang, Z and Wang, L and Xia, Z and Huang, H and Wang, W and Fang, J and Gu, Z and Sun, P and Zheng, J},
title = {Inhibitory Effects of Compounds from Plumula nelumbinis on Biofilm and Quorum Sensing Against P. aeruginosa.},
journal = {Current microbiology},
volume = {79},
number = {8},
pages = {236},
pmid = {35767197},
issn = {1432-0991},
support = {81773593//national natural science foundation of china/ ; 81872759//national natural science foundation of china/ ; 82073977//national natural science foundation of china/ ; },
abstract = {Quorum sensing (QS), which controls the survival and virulence of Pseudomonas aeruginosa, including the formation of biofilm, is considered to be a new target to overcome pathogens. The aim of this study was to identify new QS inhibitors against P. aeruginosa and provide potential treatments for clinical infections. In this study, 25 compounds were isolated from Plumula nelumbini. Among these compounds, C25 showed the most significant biofilm inhibition activity, reaching 44.63% at 100 μM without inhibiting bacterial growth. Furthermore, C25 showed significant inhibition activity of rhamnolipid, pyocyanin, and elastase. Further mechanistic studies have confirmed that C25 could downregulate key genes in the QS system, including lasI, lasR, lasA, lasB, and pqsR, and Molecular docking studies have shown that C25 can bind to the active sites of the LasR and PqsR receptors. The present study suggests that C25 is a promising QS inhibitor for treating P. aeruginosa infections.},
}
@article {pmid35764312,
year = {2022},
author = {Oh, MJ and Babeer, A and Liu, Y and Ren, Z and Wu, J and Issadore, DA and Stebe, KJ and Lee, D and Steager, E and Koo, H},
title = {Surface Topography-Adaptive Robotic Superstructures for Biofilm Removal and Pathogen Detection on Human Teeth.},
journal = {ACS nano},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsnano.2c01950},
pmid = {35764312},
issn = {1936-086X},
abstract = {The eradication of biofilms remains an unresolved challenge across disciplines. Furthermore, in biomedicine, the sampling of spatially heterogeneous biofilms is crucial for accurate pathogen detection and precise treatment of infection. However, current approaches are incapable of removing highly adhesive biostructures from topographically complex surfaces. To meet these needs, we demonstrate magnetic field-directed assembly of nanoparticles into surface topography-adaptive robotic superstructures (STARS) for precision-guided biofilm removal and diagnostic sampling. These structures extend or retract at multilength scales (micro-to-centimeter) to operate on opposing surfaces and rapidly adjust their shape, length, and stiffness to adapt and apply high-shear stress. STARS conform to complex surface topographies by entering angled grooves or extending into narrow crevices and "scrub" adherent biofilm with multiaxis motion while producing antibacterial reagents on-site. Furthermore, as the superstructure disrupts the biofilm, it captures bacterial, fungal, viral, and matrix components, allowing sample retrieval for multiplexed diagnostic analysis. We apply STARS using automated motion patterns to target complex three-dimensional geometries of ex vivo human teeth to retrieve biofilm samples with microscale precision, while providing "toothbrushing-like" and "flossing-like" action with antibacterial activity in real-time to achieve mechanochemical removal and multikingdom pathogen detection. This approach could lead to autonomous, multifunctional antibiofilm platforms to advance current oral care modalities and other fields contending with harmful biofilms on hard-to-reach surfaces.},
}
@article {pmid35764280,
year = {2022},
author = {Cao, L and Li, Y and Li, P and Zhang, X and Ni, L and Qi, L and Wen, H and Zhang, X and Zhang, Y},
title = {Application of moving bed biofilm reactor - nanofiltration - membrane bioreactor with loose nanofiltration hollow fiber membranes for synthetic roxithromycin-containing wastewater treatment: long-term performance, membrane fouling and microbial community.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {127527},
doi = {10.1016/j.biortech.2022.127527},
pmid = {35764280},
issn = {1873-2976},
abstract = {The present study operated the novel moving bed biofilm reactor-nanofiltration-membrane bioreactor (MBBR-NF-MBR) with loose polyamide NF membranes for the first time to treat roxithromycin (ROX) wastewater. Results showed that both MBBR-NF-MBRs achieved superior COD removal of 98.4% and 97.2% and excellent removal of ROX at 74.1% and 65.5%, respectively. The main membrane fouling mechanism was reversible fouling caused by the combination of abundant polysaccharides, proteins and Ca-P precipitates, which could be effectively removed by acidic cleaning. Sorption and biodegradation were the main removal routes of ROX in MBBR. Partial retention of loose NF membrane contributed to microbial metabolism and increased microbial diversity, especially the genera Hyphomicrobium in attached biofilm, which was reasonable for ROX removal. The cleavage of cladinose, demethylation, phosphorylation and β-oxidation in macrolactone ring were the main biotransformation reactions of ROX. This study provides novel insights for micropollutants wastewater treatment by using loose NF membrane in MBR.},
}
@article {pmid35762651,
year = {2022},
author = {Yao, S and Hao, L and Zhou, R and Jin, Y and Huang, J and Wu, C},
title = {Multispecies biofilms in fermentation: Biofilm formation, microbial interactions, and communication.},
journal = {Comprehensive reviews in food science and food safety},
volume = {},
number = {},
pages = {},
doi = {10.1111/1541-4337.12991},
pmid = {35762651},
issn = {1541-4337},
support = {31671849//National Natural Science Foundation of China/ ; 31871787//National Natural Science Foundation of China/ ; },
abstract = {Food fermentation is driven by microorganisms, which usually coexist as multispecies biofilms. The activities and interactions of functional microorganisms and pathogenic bacteria in biofilms have important implications for the quality and safety of fermented foods. It was verified that the biofilm lifestyle benefited the fitness of microorganisms in harsh environments and intensified the cooperation and competition between biofilm members. This review focuses on multispecies biofilm formation, microbial interactions and communication in biofilms, and the application of multispecies biofilms in food fermentation. Microbial aggregation and adhesion are important steps in the early stage of multispecies biofilm formation. Different biofilm-forming abilities and strategies among microorganisms lead to several types of multispecies biofilm formation. The spatial distribution of multispecies biofilms reflects microbial interactions and biofilm function. Then, we discuss the intrinsic factors and external manifestations of multispecies biofilm system succession. Several typical interspecies cooperation and competition modes and mechanisms of microbial communication were reviewed in this review. The main limitations of the studies included in this review are the relatively small number of studies of biofilms formed by functional microorganisms during fermentation and the lack of direct evidence for the formation process of multispecies biofilms and microbial interactions and communication within biofilms. This review aims to provide the food industry with a sufficient understanding of multispecies biofilms in food fermentation. Practical Application: Meanwhile, it offers a reference value for better controlling and utilizing biofilms during food fermentation process, and the improvement of the yield, quality, and safety of fermented products including Chinese Baijiu, cheeese,kefir, soy sauce, kombucha, and fermented olive.},
}
@article {pmid35761698,
year = {2022},
author = {Yi, Z and Yan, J and Ding, Z and Xie, J},
title = {The HD-GYP domain protein of Shewanella putrefaciens YZ08 regulates biofilm formation and spoilage activities.},
journal = {Food research international (Ottawa, Ont.)},
volume = {157},
number = {},
pages = {111466},
doi = {10.1016/j.foodres.2022.111466},
pmid = {35761698},
issn = {1873-7145},
abstract = {Shewanella putrefaciens is an important spoilage bacteria in seafood and its ability to form biofilms in food processing environments increases the chances of food spoilage. Exploring the regulatory factors associated with biofilm formation and spoilage activity in S. putrefaciens is of great significance for extending the shelf life of seafood. In this work, the regulatory function of HD-GYP domain protein K2227_17660 in spoilage microorganism S. putrefaciens YZ08 was studied. The deletion mutant Δ17660 was developed to explore the effects of K2227_17660 in c-di-GMP content regulation, motility, biofilm formation, extracellular protease activity, and spoilage potential by phenotypic and transcriptional comparison with wild-type (WT) strain. Deletion of K2227_17660 significantly increased c-di-GMP content, biofilm biomass, the production of extracellular polysaccharide, trimethylamine (TMA), and putrescine compared with WT strains, and also affected membrane fatty acid composition. Furthermore, RT-qPCR results revealed the expression levels of genes associated with biofilm biomass, spoilage and unsaturated fatty acids (UFAs) synthesis changed in a manner consistent with the phenotypes. Our results indicated that K2227_17660 possesses phosphodiesterase (PDE) activity that controls the biofilm biomass and spoilage potential of S. putrefaciens. This study provided a basis for a correlation between c-di-GMP and food spoilage in S. putrefaciens, providing new insights into the control of food quality and safety.},
}
@article {pmid35761654,
year = {2022},
author = {Wu, Y and Ma, F and Pang, X and Chen, Y and Niu, A and Tan, S and Chen, X and Qiu, W and Wang, G},
title = {Involvement of AprD in regulating biofilm structure, matrix secretion, and cell metabolism of meat-borne Pseudomonas fragi during chilled storage.},
journal = {Food research international (Ottawa, Ont.)},
volume = {157},
number = {},
pages = {111400},
doi = {10.1016/j.foodres.2022.111400},
pmid = {35761654},
issn = {1873-7145},
abstract = {Pseudomonas fragi is by far one of the most threatening species in the spoilage of chilled meat that is stored under aerobic conditions. The membrane protein AprD is a well-established regulator controlling protease secretion in Pseudomonas spp. However, its exact roles in modulating metabolic pathways and spoilage potential of P. fragi at the molecular level remain undefined. Here, an in-frame deletion mutation of aprD was used to explore the impacts on their biofilm structure, matrix secretion, and cell metabolism. The results showed that ΔaprD formed relatively disorganized loose aggregation in biofilm, resulting in a thinner structure and more dead cells. Meanwhile, marked changes in the content of extracellular carbohydrates and proteins were observed. Furthermore, intracellular metabolomic profiling revealed the involvement of aprD in several cellular metabolic pathways, mostly including the carbohydrate pathway, amino acid pathway, and nucleotide pathway, while the characterization of extracellular metabolism clarified the variations in the spoilage-related metabolites (e.g., creatine, IMP, spermine, fatty acids, amino acids, and oligopeptides) could be highly correlated with aprD deletion. In this finding, we indicated that aprD could be responsible for cell reproduction and in situ spoilage potential of P. fragi NMC25 during chilled storage by controlling related metabolism and nutrients utilization. Thus, our results will contribute to an improved understanding of the regulatory mechanism of aprD gene in meat spoilage contaminated with P. fragi, which can be valuable to ensure the quality and safety of meat.},
}
@article {pmid35761627,
year = {2022},
author = {Byun, KH and Han, SH and Choi, MW and Kim, BH and Park, SH and Ha, SD},
title = {Biofilm eradication ability of phage cocktail against Listeria monocytogenes biofilms formed on food contact materials and effect on virulence-related genes and biofilm structure.},
journal = {Food research international (Ottawa, Ont.)},
volume = {157},
number = {},
pages = {111367},
doi = {10.1016/j.foodres.2022.111367},
pmid = {35761627},
issn = {1873-7145},
abstract = {Listeria monocytogenes is a foodborne pathogen that can form biofilms in food processing facilities even under unfavorable growth environment. This study aimed to evaluate the biofilm eradication ability of Listeria-specific bacteriophage (phage) cocktail (LMPC01+02+03) against L. monocytogenes young (1 day) and mature (3 days) biofilms formed on food contact materials (FCMs: polyethylene, polypropylene, and stainless steel) at 4, 15, and 30 °C. In addition, virulence-related genes and biofilm structure parameters of the phage-treated biofilms were investigated. The biofilm eradication ability of the phage cocktail was evaluated on 96 well and MBEC plate, and the results revealed that a multiplicity-of-infection (MOI) 100 of the phage cocktail exhibited the ability of eradicate biofilms. Using MOI 100, the phage cocktail treatment on the biofilms formed on FCMs for 8 h reduced over 2 log CFU/cm2 of the young biofilms, and approximately 1 log CFU/cm2 of the mature biofilms. In addition, the phage treatment against the biofilms resulted in a significant up-regulation of two genes (flaA and motB), and up/down-regulation or no changes in three genes (hlyA, prfA, and actA). Confocal and scanning electron microscopy images revealed the loss of the biofilm matrix after the phage treatment, and quantitative analysis revealed a reduction in the structural parameters of the biofilm, except the microcolonies at the substratum level, which increased. These results suggested that MOI 100 of the phage cocktail (LMPC01+02+03) was an effective tool for eradicating L. monocytogenes biofilms formed on FCMs, and it is essential to develop a countermeasure to eradicate the biofilm remaining after phage treatment.},
}
@article {pmid35761055,
year = {2022},
author = {Hofer, U},
title = {A new wrinkle in biofilm structure.},
journal = {Nature reviews. Microbiology},
volume = {},
number = {},
pages = {},
pmid = {35761055},
issn = {1740-1534},
}
@article {pmid35760284,
year = {2022},
author = {Liu, L and He, Y and Yang, H and Liu, W and Zheng, S and Qi, Y and Zhou, D and Zhang, Y and Yin, Z},
title = {Nlp enhances biofilm formation by Yersinia pestis biovar microtus.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {105659},
doi = {10.1016/j.micpath.2022.105659},
pmid = {35760284},
issn = {1096-1208},
abstract = {Biofilms formed by Yersinia pestis are able to attach to and block flea's proventriculus, which stimulates the transmission of this pathogen from fleas to mammals. In this study, we found that Nlp (YP1143) enhanced biofilm formation by Y. pestis and had regulatory effects on biofilm-associated genes at the transcriptional level. Phenotypic assays, including colony morphology assay, crystal violet staining, and Caenorhabditis elegans biofilm assay, disclosed that Nlp strongly promoted biofilm formation by Y. pestis. Further gene regulation assays showed that Nlp stimulated the expression of hmsHFRS, hmsCDE and hmsB, while had no regulatory effect on the expression of hmsT and hmsP at the transcriptional level. These findings promoted us to gain more understanding of the complex regulatory circuits controlling biofilm formation by Y. pestis.},
}
@article {pmid35760234,
year = {2022},
author = {Jin, Y and Zhao, B and Guo, W and Li, Y and Min, J and Miao, W},
title = {Penetration and photodynamic ablation of drug-resistant biofilm by cationic Iron oxide nanoparticles.},
journal = {Journal of controlled release : official journal of the Controlled Release Society},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.jconrel.2022.06.038},
pmid = {35760234},
issn = {1873-4995},
abstract = {As we step into the post-antibiotic era, the accelerated emergence of antibiotic-resistant pathogenic bacteria poses an increasingly serious threat to public health. The formation of antibiotic-resistant biofilms further challenges currently available drugs and treatment options, calling for novel strategies for effective ablation of such biofilm with minimal concern on safety and development of resistance. Herein, we report a novel type of photodynamic nanoagent, composed of chlorin e6 (Ce6)-loaded water-soluble chitosan-coated iron oxide nanoparticles (named Ce6@WCS-IONP), for drug-resistant bacteria killing and biofilm eradication. The fabricated Ce6@WCS-IONP has negligible toxicity to mammalian cells and exhibited equivalent singlet oxygen generation capacity to free Ce6; however, its association with methicillin-resistant Staphylococcus aureus (MRSA) was greatly enhanced, as evidenced by flow cytometry analysis and transmission electron microscope. In vitro studies verified that Ce6@WCS-IONP has superior photodynamic bactericidal effect against planktonic MRSA. Furthermore, with the aid of the cationic nature and small size, Ce6@WCS-IONP could effectively penetrate into MRSA biofilm, revealed by 3D fluorescence imaging. Both biomass analysis and viable bacteria counting demonstrated that Ce6@WCS-IONP showed potent biofilm ablation efficacy, averagely 7.1 log unit lower than that in free Ce6 group upon identical light irradiation. In addition, local treatment of MRSA-infected mice with Ce6@WCS-IONP plus light irradiation resulted in significant antibacterial and wound healing effect, accompanied by good biocompatibility in vivo. Collectively, photosensitizer-loaded cationic IONP with effective biofilm penetration and photodynamic eradication potential might be a promising nano platform in fighting against antibiotic-resistant microbial pathogen and biofilm.},
}
@article {pmid35760177,
year = {2022},
author = {Vendrell-Puigmitja, L and Proia, L and Espinosa, C and Barral-Fraga, L and Cañedo-Argüelles, M and Osorio, V and Casas, C and Llenas, L and Abril, M},
title = {Hypersaline mining effluents affect the structure and function of stream biofilm.},
journal = {The Science of the total environment},
volume = {},
number = {},
pages = {156966},
doi = {10.1016/j.scitotenv.2022.156966},
pmid = {35760177},
issn = {1879-1026},
abstract = {The salinisation of freshwater ecosystems is a global environmental problem that threatens biodiversity, ecosystem functioning and human welfare. The aim of this study was to investigate the potential impact of a realistic salinity gradient on the structure and functioning of freshwater biofilms. The salinity gradient was based on the real ion concentration of a mining effluent from an abandoned mine in Germany. We exposed biofilm from a pristine stream to 5 increasing salinities (3 to 100 g L-1) under controlled conditions in artificial streams for 21 days. We evaluated its functional (photosynthetic efficiency, nutrient uptake, and microbial respiration) and structural responses (community composition, algal biomass and diatom, cyanobacteria and green algae metrics) over time. Then we compared their responses with an unexposed biofilm used as control. The functionality and structure of the biofilm exposed to the different salinities significantly decreased after short-term and long-term exposure, respectively. The community composition shifted to a new stable state where the most tolerant species increased their abundances. At the same time, we observed an increase in the community tolerance (measured as Pollution-Induced Community Tolerance) along the salinity gradient. This study provides relevant information on the salt threshold concentrations that can substantially damage algal cells (i.e., between 15 and 30 g L-1). The results provide new insights regarding the response and adaptation of stream biofilm to salinity and its potential implications at the ecosystem level.},
}
@article {pmid35759644,
year = {2022},
author = {Ben Hur, D and Kapach, G and Wani, NA and Kiper, E and Ashkenazi, M and Smollan, G and Keller, N and Efrati, O and Shai, Y},
title = {Antimicrobial Peptides against Multidrug-Resistant Pseudomonas aeruginosa Biofilm from Cystic Fibrosis Patients.},
journal = {Journal of medicinal chemistry},
volume = {},
number = {},
pages = {},
doi = {10.1021/acs.jmedchem.2c00270},
pmid = {35759644},
issn = {1520-4804},
abstract = {Lung infection is the leading cause of morbidity and mortality in cystic fibrosis (CF) patients and is mainly dominated by Pseudomonas aeruginosa. Treatment of CF-associated lung infections is problematic because the drugs are vulnerable to multidrug-resistant pathogens, many of which are major biofilm producers like P. aeruginosa. Antimicrobial peptides (AMPs) are essential components in all life forms and exhibit antimicrobial activity. Here we investigated a series of AMPs (d,l-K6L9), each composed of six lysines and nine leucines but differing in their sequence composed of l- and d-amino acids. The d,l-K6L9 peptides showed antimicrobial and antibiofilm activities against P. aeruginosa from CF patients. Furthermore, the data revealed that the d,l-K6L9 peptides are stable and resistant to degradation by CF sputum proteases and maintain their activity in a CF sputum environment. Additionally, the d,l-K6L9 peptides do not induce bacterial resistance. Overall, these findings should assist in the future development of alternative treatments against resistant bacterial biofilms.},
}
@article {pmid35758758,
year = {2022},
author = {Klementiev, AD and Whiteley, M},
title = {Development of a Versatile, Low-Cost Electrochemical System to Study Biofilm Redox Activity at the Micron Scale.},
journal = {Applied and environmental microbiology},
volume = {},
number = {},
pages = {e0043422},
doi = {10.1128/aem.00434-22},
pmid = {35758758},
issn = {1098-5336},
abstract = {Spatially resolving chemical landscapes surrounding microbial communities can provide insight into chemical interactions that dictate cellular physiology. Electrochemical techniques provide an attractive option for studying these interactions due to their robustness and high sensitivity. Unfortunately, commercial electrochemical platforms that are capable of measuring chemical activity on the micron scale are often expensive and do not easily perform multiple scanning techniques. Here, we report development of an inexpensive electrochemical system that features a combined micromanipulator and potentiostat component capable of scanning surfaces while measuring molecular concentrations or redox profiles. We validate this experimental platform for biological use with a two-species biofilm model composed of the oral bacterial pathogen Aggregatibacter actinomycetemcomitans and the oral commensal Streptococcus gordonii. We measure consumption of H2O2 by A. actinomycetemcomitans biofilms temporally and spatially, providing new insights into how A. actinomycetemcomitans responds to this S. gordonii-produced metabolite. We advance our platform to spatially measure redox activity above biofilms. Our analysis supports that redox activity surrounding biofilms is species specific, and the region immediately above an S. gordonii biofilm is highly oxidized compared to that above an A. actinomycetemcomitans biofilm. This work provides description and validation of a versatile, quantitative framework for studying bacterial redox-mediated physiology in an integrated and easily adaptable experimental platform. IMPORTANCE Scanning electrochemical probe microscopy methods can provide information of the chemical environment along a spatial surface with micron-scale resolution. These methods often require expensive instruments that perform optimized and highly sensitive niche techniques. Here, we describe a novel system that combines a micromanipulator that scans micron-sized electrodes across the surface of bacterial biofilms and a potentiostat, which performs various electrochemical techniques. This platform allows for spatial measurement of chemical gradients above live bacteria in real time, and as proof of concept, we utilize this setup to map H2O2 detoxification above an oral pathogen biofilm. We increased the versatility of this platform further by mapping redox potentials of biofilms in real time on the micron scale. Together, this system provides a technical framework for studying chemical interactions among microbes.},
}
@article {pmid35758640,
year = {2022},
author = {Wan, P and Guo, W and Wang, Y and Deng, M and Xiao, C and Chen, X},
title = {Photosensitizer-Polypeptide Conjugate for Effective Elimination of Candida albicans Biofilm.},
journal = {Advanced healthcare materials},
volume = {},
number = {},
pages = {e2200268},
doi = {10.1002/adhm.202200268},
pmid = {35758640},
issn = {2192-2659},
abstract = {Persistent fungal infections caused by biofilms seriously endanger human health. In this study, a photosensitizer-polypeptide conjugate (PPa-cP) comprising a photosensitizer, pyropheophorbide a (PPa), and a cationic polypeptide (cP) was readily synthesized for effective antifungal and antibiofilm treatment. Compared with free PPa, the cationic PPa-cP showed enhanced binding ability to the negatively charged surface of Candida albicans (C. albicans) through electrostatic interactions. As a result, PPa-cP exhibited effective antifungal efficiency against both C. albicans and fluconazole-resistant C. albicans in vitro under light irradiation. The minimum inhibitory concentration (MIC) of PPa-cP for both C. albicans and fluconazole-resistant C. albicans was 1 μM. In addition, PPa-cP also showed improved penetration in C. albicans biofilm, thus effectively eliminating C. albicans biofilm by photodynamic effect. More importantly, PPa-cP demonstrated significantly enhanced therapeutic effects in a fluconazole-resistant C. albicans-infected rat model with minimal side effects. In conclusion, the current work presents an effective strategy to combat biofilm infections associated with biomedical equipment. This article is protected by copyright. All rights reserved.},
}
@article {pmid35756812,
year = {2022},
author = {Filemban, H and Bhadila, G and Wang, X and Melo, MAS and Oates, TW and Weir, MD and Sun, J and Xu, HHK},
title = {Novel low-shrinkage-stress bioactive nanocomposite with anti-biofilm and remineralization capabilities to inhibit caries.},
journal = {Journal of dental sciences},
volume = {17},
number = {2},
pages = {811-821},
doi = {10.1016/j.jds.2021.09.032},
pmid = {35756812},
issn = {2213-8862},
abstract = {Background/purpose: A common reason for dental composite restoration failure is recurrent caries at the margins. Our objectives were to: (1) develop a novel low-shrinkage-stress, antibacterial and remineralizing resin composite; (2) evaluate the effects of dimethylaminohexadecyl methacrylate (DMAHDM) on mechanical properties, biofilm inhibition, calcium (Ca) and phosphate (P) ion release, degree of conversion, and shrinkage stress on the new low-shrinkage-stress resin composite for the first time.<br><br>Material and methods: The resin consisted of urethane dimethacrylate (UDMA) and triethylene glycol divinylbenzyl ether (TEG-DVBE) with high resistance to salivary hydrolytic degradation. Composites were made with 0%-8% of DMAHDM for antibacterial activity, and 20% of nanoparticles of amorphous calcium phosphate (NACP) for remineralization. Mechanical properties and Streptococcus mutans biofilm growth on composites were assessed. Ca and P ion releases, degree of conversion and shrinkage stress were evaluated.<br><br>Results: Adding 2-5% DMAHDM and 20% NACP into the low-shrinkage-stress composite did not compromise the mechanical properties (p > 0.05). The incorporation of DMAHDM greatly reduced S. mutans biofilm colony-forming units by 2-5 log and lactic acid production by 7 folds, compared to a commercial composite (p < 0.05). Adding 5% DMAHDM did not compromise the Ca and P ion release. The low-shrinkage-stress composite maintained a high degree of conversion of approximately 70%, while reducing the shrinkage stress by 37%, compared to a commercial control (p < 0.05).<br><br>Conclusion: The bioactive low-shrinkage-stress composite reduced the polymerization shrinkage stress, without compromising other properties. Increasing the DMAHDM content increased the antibacterial effect in a dose-dependent manner.},
}
@article {pmid35756538,
year = {2022},
author = {Cho, E and Hwang, JY and Park, JS and Oh, D and Oh, DC and Park, HG and Shin, J and Oh, KB},
title = {Inhibition of Streptococcus mutans adhesion and biofilm formation with small-molecule inhibitors of sortase A from Juniperus chinensis.},
journal = {Journal of oral microbiology},
volume = {14},
number = {1},
pages = {2088937},
doi = {10.1080/20002297.2022.2088937},
pmid = {35756538},
issn = {2000-2297},
abstract = {Background: Streptococcus mutans, an important Gram-positive pathogen in dental caries, uses sortase A (SrtA) to anchor surface proteins to the bacterial cell wall, thereby promoting biofilm formation and attachment to the tooth surface.<br><br>Design: Based on activity-guided separation, inhibitors of S. mutans SrtA were isolated from Juniperus chinensis and identified through combined spectroscopic analysis. Further effects of isolated SrtA inhibitor on S. mutans were evaluated on bacterial aggregation, adherence and biofilm formation.<br><br>Results: Six compounds (1-6) were isolated from the dried heartwood of J. chinensis. A novel compound designated 3',3"-dihydroxy-(-)-matairesinol (1) was identified, which exhibited potent inhibitory activity toward S. mutans SrtA (IC50 = 16.1 μM) without affecting microbial viability (minimum inhibitory concentration > 300 μM). The results of subsequent bioassays using compound 1 indicated that this compound inhibits S. mutans aggregation, adhesion and biofilm formation on solid surfaces by inhibiting SrtA activity. The onset and magnitude of inhibition of adherence and biofilm formation in S. mutans treated with compound 1 at 4× the SrtA IC50 are comparable to the behaviors of the untreated srtA-deletion mutant.<br><br>Conclusion: Our findings suggest that small-molecule inhibitors of S. mutans SrtA may be useful for the prevention of dental plaque and treatment of dental microbial diseases.},
}
@article {pmid35756067,
year = {2022},
author = {Li, Y and Chen, N and Wu, Q and Liang, X and Yuan, X and Zhu, Z and Zheng, Y and Yu, S and Chen, M and Zhang, J and Wang, J and Ding, Y},
title = {A Flagella Hook Coding Gene flgE Positively Affects Biofilm Formation and Cereulide Production in Emetic Bacillus cereus.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {897836},
doi = {10.3389/fmicb.2022.897836},
pmid = {35756067},
issn = {1664-302X},
abstract = {Bacillus cereus, an important foodborne pathogen, poses a risk to food safety and quality. Robust biofilm formation ability is one of the key properties that is responsible for the food contamination and food poisoning caused by B. cereus, especially the emetic strains. To investigate the mechanism of biofilm formation in emetic B. cereus strains, we screened for the mutants that fail to form biofilms by using random mutagenesis toward B. cereus 892-1, an emetic strain with strong biofilm formation ability. When knocking out flgE, a flagellar hook encoding gene, the mutant showed disappearance of flagellar structure and swimming ability. Further analysis revealed that both pellicle and ring presented defects in the null mutant compared with the wild-type and complementary strains. Compared with the flagellar paralytic strains Δ motA and Δ motB, the inhibition of biofilm formation by Δ flgE is not only caused by the inhibition of motility. Interestingly, Δ flgE also decreased the synthesis of cereulide. To our knowledge, this is the first report showing that a flagellar component can both affect the biofilm formation and cereulide production in emetic B. cereus, which can be used as the target to control the biohazard of emetic B. cereus.},
}
@article {pmid35756031,
year = {2022},
author = {Liu, J and Zhu, Y and Li, Y and Lu, Y and Xiong, K and Zhong, Q and Wang, J},
title = {Bacteriophage-Resistant Mutant of Enterococcus faecalis Is Impaired in Biofilm Formation.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {913023},
doi = {10.3389/fmicb.2022.913023},
pmid = {35756031},
issn = {1664-302X},
abstract = {Enterococcus faecalis is a common gram-positive non-spore-forming bacterium in nature and is found in the upper respiratory tract, intestine, and mouth of healthy people. E. faecalis is also one of the common pathogens causing nosocomial infections and is resistant to several antibiotics commonly used in practice. Thus, treating drug-resistant E. faecalis with antibiotics is challenging, and new approaches are needed. In this study, we isolated a bacteriophage named EFap02 that targets E. faecalis strain EFa02 from sewage at Southwest Hospital. Phage EFap02 belongs to the Siphoviridae family with a long tail of approximately 210 nm, and EFap02 can tolerate a strong acid and alkali environment and high temperature. Its receptor was identified as the capsular polysaccharide. Phage-resistant mutants had loss-of-function mutations in glycosyltransferase (gtr2), which is responsible for capsular polysaccharide biosynthesis, and this caused the loss of capsular polysaccharide and interruption of phage adsorption. Although phage-resistant mutants against EFap02 can be selected, such mutants are impaired in biofilm formation due to the loss of capsular polysaccharide, which compromises its virulence. Therefore, this study provided a detailed description of the E. faecalis EFap02 phage with the potential for treating E. faecalis infection.},
}
@article {pmid35754328,
year = {2022},
author = {Ghafil, JA and İbrahim, BMS and Zgair, AK},
title = {Coating indwelling urinary catheters with moxifloxacin prevents biofilm formation by Burkholderia cepacia.},
journal = {Polimery w medycynie},
volume = {},
number = {},
pages = {},
doi = {10.17219/pim/149986},
pmid = {35754328},
issn = {0370-0747},
abstract = {BACKGROUND: Burkholderia cepacia adhesion and biofilm formation onto abiotic surfaces is an important feature of clinically relevant isolates. The in vitro biofilm formation of B. cepacia onto coated indwelling urinary catheters (IDCs) with moxifloxacin has not been previously investigated.<br><br>OBJECTIVES: To examine the ability of B. cepacia to form biofilms on IDCs and the effect of coating IDCs with moxifloxacin on biofilm formation by B. cepacia in vitro.<br><br>MATERIAL AND METHODS: The adhesion of B. cepacia to coated and uncoated IDCs with moxifloxacin was evaluated. Pieces of IDCs were coated with moxifloxacin (adsorption method). The spectrophotometric method was used to check moxifloxacin leaching into tubes. Coated and uncoated tubes were incubated with 107 colony forming units (cfu)/mL of B. cepacia. The viable bacterial count was used to count the number of bacteria adhered to coated and uncoated IDC pieces.<br><br>RESULTS: A significant adhesion of B. cepacia to uncoated IDC pieces started 15 min after the incubation in a bacterial suspension (107 cfu/mL). A maximum adhesion was observed at 48 h. The pretreatment of IDCs with 100 μg/mL of moxifloxacin produced the best adsorption of antibiotic onto the IDCs. Coating IDC pieces with moxifloxacin significantly reduced the adhesion and biofilm formation of B. cepacia (p < 0.05) at various time intervals (1 h, 4 h and 24 h).<br><br>CONCLUSIONS: The present study has demonstrated for the first time that coated IDCs with moxifloxacin reduce B. cepacia adhesion and biofilm formation. This finding has opened the door to the production of the new generation IDCs that prevent bacteria from attaching and forming biofilms.},
}
@article {pmid35753599,
year = {2022},
author = {Mishra, P and Ch, S and Hong, SJ and Biswas, S and Roy, S},
title = {Antimicrobial peptide S100A12 (calgranulin C) inhibits growth, biofilm formation, pyoverdine secretion and suppresses type VI secretion system in Pseudomonas aeruginosa.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {105654},
doi = {10.1016/j.micpath.2022.105654},
pmid = {35753599},
issn = {1096-1208},
abstract = {Pseudomonas aeruginosa is an opportunistic pathogen and is the major cause of corneal infections in India and worldwide. The increase in antimicrobial resistance among Pseudomonas has prompted rise in significant research to develop alternative therapeutics. Antimicrobial peptides (AMPs) are considered as potent alternatives to combat bacterial infections. In this study, we investigated the role of S100A12, a host defense peptide, against PAO1 and an ocular clinical isolate. Increased expression of S100A12 was observed in corneal tissues obtained from Pseudomonas keratitis patients by immunohistochemistry. S100A12 significantly inhibited growth of Pseudomonas in vitro as determined from colony forming units. Furthermore, recombinant S100A12 reduced the corneal opacity and the bacterial load in a mouse model of Pseudomonas keratitis. Transcriptome changes in PAO1 in response to S100A12 was investigated using RNA sequencing. The pathway analysis of transcriptome data revealed that S100A12 inhibits expression of genes involved in pyoverdine synthesis and biofilm formation. It also impedes several important pathways like redox, pyocyanin synthesis and type 6 secretion system (T6SS). The transcriptome data was further validated by checking the expression of several affected genes by quantitative PCR. Our study sheds light on how S100A12 impacts Pseudomonas and that it might have the potential to be used as therapeutic intervention in addition to antibiotics to combat infection in future.},
}
@article {pmid35752611,
year = {2022},
author = {Revie, NM and Iyer, KR and Maxson, ME and Zhang, J and Yan, S and Fernandes, CM and Meyer, KJ and Chen, X and Skulska, I and Fogal, M and Sanchez, H and Hossain, S and Li, S and Yashiroda, Y and Hirano, H and Yoshida, M and Osada, H and Boone, C and Shapiro, RS and Andes, DR and Wright, GD and Nodwell, JR and Del Poeta, M and Burke, MD and Whitesell, L and Robbins, N and Cowen, LE},
title = {Targeting fungal membrane homeostasis with imidazopyrazoindoles impairs azole resistance and biofilm formation.},
journal = {Nature communications},
volume = {13},
number = {1},
pages = {3634},
pmid = {35752611},
issn = {2041-1723},
support = {MFE-176478//Gouvernement du Canada | Canadian Institutes of Health Research (Instituts de Recherche en Santé du Canada)/ ; FDN-143264//Gouvernement du Canada | Canadian Institutes of Health Research (Instituts de Recherche en Santé du Canada)/ ; FDN-154288//Gouvernement du Canada | Canadian Institutes of Health Research (Instituts de Recherche en Santé du Canada)/ ; JP19H05640//MEXT | Japan Society for the Promotion of Science (JSPS)/ ; 17H06411//MEXT | Japan Society for the Promotion of Science (JSPS)/ ; R01AI073289//U.S. Department of Health &amp; Human Services | National Institutes of Health (NIH)/ ; AI116420//U.S. Department of Health &amp; Human Services | National Institutes of Health (NIH)/ ; AI125770//U.S. Department of Health &amp; Human Services | National Institutes of Health (NIH)/ ; R01 5R01AI135812//U.S. Department of Health &amp; Human Services | National Institutes of Health (NIH)/ ; },
abstract = {Fungal infections cause more than 1.5 million deaths annually. With an increase in immune-deficient susceptible populations and the emergence of antifungal drug resistance, there is an urgent need for novel strategies to combat these life-threatening infections. Here, we use a combinatorial screening approach to identify an imidazopyrazoindole, NPD827, that synergizes with fluconazole against azole-sensitive and -resistant isolates of Candida albicans. NPD827 interacts with sterols, resulting in profound effects on fungal membrane homeostasis and induction of membrane-associated stress responses. The compound impairs virulence in a Caenorhabditis elegans model of candidiasis, blocks C. albicans filamentation in vitro, and prevents biofilm formation in a rat model of catheter infection by C. albicans. Collectively, this work identifies an imidazopyrazoindole scaffold with a non-protein-targeted mode of action that re-sensitizes the leading human fungal pathogen, C. albicans, to azole antifungals.},
}
@article {pmid35750233,
year = {2022},
author = {Cheng, Y and Wang, H and Deng, Z and Wang, J and Liu, Z and Chen, Y and Ma, Y and Li, B and Yang, L and Zhang, Z and Wu, L},
title = {Efficient removal of Imidacloprid and nutrients by algae-bacteria biofilm reactor (ABBR) in municipal wastewater: Performance, mechanisms and the importance of illumination.},
journal = {Chemosphere},
volume = {},
number = {},
pages = {135418},
doi = {10.1016/j.chemosphere.2022.135418},
pmid = {35750233},
issn = {1879-1298},
abstract = {Neonicotinoids, such as Imidacloprid (IMI), are frequently detected in water and wastewater, posing a threat on both the environment and the health of living things. In this work, a novel algae-bacteria biofilm reactor (ABBR) was constructed to remove IMI and conventional nutrients from municipal wastewater, aiming to explore the removal effect and advantage of ABBR. Results showed that ABBR achieved 74.9% removal of IMI under 80 μmol·m-2·s-1 light, higher than photobioreactor (PBR) without biofilm (61.2%) or ABBR under 40 μmol·m-2·s-1 light (48.4%) after 16 days of operation. Moreover, it also showed that ABBR allowed a marked improvement on the removal of total dissolved nitrogen (TDN), total dissolved phosphorus (TDP) and soluble chemical oxygen demand (sCOD). ABBR showed different IMI removal efficiencies and bacterial communities under different light conditions, indicating that light played an important role in driving ABBR. The merits of ABBR are including (i) ABBR showed rapid pollutant removal in a short time, (ii) in ABBR, stable consortiums were formed and chlorophyll content in effluent was very low, (iii) compared with PBR, degradation products in ABBR showed lower biological toxicity. Our study highlights the benefits of ABBR on IMI removing from municipal wastewater and provides an effective and environment-friendly engineering application potential of IMI removal.},
}
@article {pmid35750120,
year = {2022},
author = {Chen, X and Yuan, C and Zhu, Y and Liu, H and Chen, W and Zhang, Q},
title = {Bioaugmentation with Acinetobacter sp. TAC-1 to enhance nitrogen removal in swine wastewater by moving bed biofilm reactor inoculated with bacteria.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {127506},
doi = {10.1016/j.biortech.2022.127506},
pmid = {35750120},
issn = {1873-2976},
abstract = {To enhance the performance of moving bed biofilm reactor (MBBR) inoculated with heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria, bioaugmentation with Acinetobacter sp. TAC-1 was firstly employed and then the treatment performance for real swine wastewater was presented in this study. Results indicated that NH4+-N and TN removal rates of bioaugmented reactor were significantly improved from 16.53 mg/L/h and 16.15 mg/L/h to 24.58 mg/L/h and 24.45 mg/L/h, respectively. The efficient removal performance (NH4+-N 95.01%, TN 86.40%) for real swine wastewater was achieved within 24 h. Microbial analysis indicated that the composition of functional bacteria varied with the introduction of Acinetobacter sp. TAC-1, especially the abundance of Acinetobacter, Paracoccus and Rhodococcus related to the nitrogen removal. Furthermore, bioaugmentation with Acinetobacter sp. TAC-1 increased abundance of enzymes and functional genes (nirS, nirK and norZ) corresponding to denitrification that may be responsible for the enhanced nitrogen removal performance.},
}
@article {pmid35749910,
year = {2022},
author = {Di Ciccio, P and Rubiola, S and Panebianco, F and Lomonaco, S and Allard, M and Bianchi, DM and Civera, T and Chiesa, F},
title = {Biofilm formation and genomic features of Listeria monocytogenes strains isolated from meat and dairy industries located in Piedmont (Italy).},
journal = {International journal of food microbiology},
volume = {378},
number = {},
pages = {109784},
doi = {10.1016/j.ijfoodmicro.2022.109784},
pmid = {35749910},
issn = {1879-3460},
abstract = {Listeria monocytogenes is considered a major challenge for the food industry as it can persist for long periods in food processing plants by forming biofilms. The aims of this study were: i) to assess the biofilm producing ability of 57 Listeria monocytogenes isolates previously subjected to whole-genome sequencing (WGS); ii) to compare the levels of biofilm formation with the presence or absence of biofilm associated genes. To determine the presence or absence of a known set of biofilm associated genes, a comparative genomic analysis was performed on each strain. Among Listeria monocytogenes isolates, 58 %, 38.5 % and 3.5 % exhibited weak, moderate or strong biofilm production, respectively. No difference in biofilm production was observed between food and environmental isolates. The percentage of Listeria monocytogenes strains isolated from meat products (57 %) classified as moderate or strong biofilm producers was higher than the percentage obtained for strains isolated from dairy products (28 %). The presence of the Stress Survival Islet 1, the arsD stress gene and the truncated inlA protein was significantly associated with increased levels of biofilm. Combining biofilm phenotype with molecular and genotyping data may provide the opportunity to better understand the relationship between genes linked to biofilm formation in Listeria monocytogenes.},
}
@article {pmid35749894,
year = {2022},
author = {Balu, S and Bhunia, S and Gachhui, R and Mukherjee, J},
title = {Polycyclic aromatic hydrocarbon sequestration by intertidal phototrophic biofilms cultivated in hydrophobic and hydrophilic biofilm-promoting culture vessels.},
journal = {Journal of hazardous materials},
volume = {437},
number = {},
pages = {129318},
doi = {10.1016/j.jhazmat.2022.129318},
pmid = {35749894},
issn = {1873-3336},
abstract = {Phototrophic biofilms collected from intertidal sediments of the world's largest tidal mangrove forest were cultured in two sets of a biofilm-promoting culture vessel having hydrophilic glass surface and hydrophobic polymethyl methacrylate surface wherein 16 priority polycyclic aromatic hydrocarbons (PAHs) were spiked. Biofilms from three locations of the forest were most active in sequestering 98-100% of the spiked pollutants. PAH challenge did not alter the biofilm phototrophic community composition; rather biofilm biomass production and synthesis of photosynthetic pigments and extracellular polymeric substances (EPS) were enhanced. Photosynthetic pigment and EPS synthesis were sensitive to vessel-surface property. The lowest mean residual amounts of PAHs in the liquid medium as well as inside the biofilm were recorded in the very biofilm cultivated in the hydrophobic flask where highest values of biofilm biomass, total chlorophyll, released polysaccharidic (RPS) carbohydrates, RPS uronic acids, capsular polysaccharidic (CPS) carbohydrates, CPS proteins, CPS uronic acids and EPS hydrophobicity were obtained. Ratios of released RPS proteins: polysaccharides increased during PAH sequestration whereas the ratios of CPS proteins: polysaccharides remained constant. Efficacious PAH removal by the overlying phototrophic biofilm will reduce the entry of these contaminants in the sediments underneath and this strategy could be a model for "monitored natural recovery".},
}
@article {pmid35749478,
year = {2022},
author = {Nishimura, A and Nakagami, K and Kan, K and Morita, F and Takagi, H},
title = {Arginine inhibits Saccharomyces cerevisiae biofilm formation by inducing endocytosis of the arginine transporter Can1.},
journal = {Bioscience, biotechnology, and biochemistry},
volume = {},
number = {},
pages = {},
doi = {10.1093/bbb/zbac094},
pmid = {35749478},
issn = {1347-6947},
abstract = {Biofilms are formed by the aggregation of microorganisms into multicellular structures that adhere to surfaces. Biofilm formation by yeast is a critical issue in clinical and industrial fields because of the strong adhesion of yeast biofilm to abiotic surfaces and tissues. Here, we clarified the arginine-mediated inhibition of biofilm formation by yeast. First, we showed that arginine inhibits biofilm formation in fungi such as Saccharomyces cerevisiae, Candida glabrata, and Cladosporium cladosporioides, but not in bacteria. In regard to the underlying mechanism, biochemical analysis indicated that arginine inhibits biofilm formation by suppressing Flo11-dependent flocculation. Intriguingly, a strain with deletion of the arginine transporter-encoding CAN1 was insensitive to arginine-mediated inhibition of biofilm formation. Finally, Can1 endocytosis appeared to be required for the inhibitory mechanism of biofilm formation by arginine. The present results could help to elucidate the molecular mechanism of yeast biofilm formation and its control.},
}
@article {pmid35746441,
year = {2022},
author = {Dollery, SJ and Harro, JM and Wiggins, TJ and Wille, BP and Kim, PC and Tobin, JK and Bushnell, RV and Tasker, NJPER and MacLeod, DA and Tobin, GJ},
title = {Select Whole-Cell Biofilm-Based Immunogens Protect against a Virulent Staphylococcus Isolate in a Stringent Implant Model of Infection.},
journal = {Vaccines},
volume = {10},
number = {6},
pages = {},
doi = {10.3390/vaccines10060833},
pmid = {35746441},
issn = {2076-393X},
support = {R43AI145457/NH/NIH HHS/United States ; },
abstract = {Many microbes of concern to human health remain without vaccines. We have developed a whole-microbe inactivation technology that enables us to rapidly inactivate large quantities of a pathogen while retaining epitopes that were destroyed by previous inactivation methods. The method that we call UVC-MDP inactivation can be used to make whole-cell vaccines with increased potency. We and others are exploring the possibility of using improved irradiation-inactivation technologies to develop whole-cell vaccines for numerous antibiotic-resistant microbes. Here, we apply UVC-MDP to produce candidate MRSA vaccines which we test in a stringent tibia implant model of infection challenged with a virulent MSRA strain. We report high levels of clearance in the model and observe a pattern of protection that correlates with the immunogen protein profile used for vaccination.},
}
@article {pmid35745740,
year = {2022},
author = {Falanga, A and Maione, A and La Pietra, A and de Alteriis, E and Vitale, S and Bellavita, R and Carotenuto, R and Turrà, D and Galdiero, S and Galdiero, E and Guida, M},
title = {Competitiveness during Dual-Species Biofilm Formation of Fusarium oxysporum and Candida albicans and a Novel Treatment Strategy.},
journal = {Pharmaceutics},
volume = {14},
number = {6},
pages = {},
doi = {10.3390/pharmaceutics14061167},
pmid = {35745740},
issn = {1999-4923},
abstract = {During an infection, a single or multispecies biofilm can develop. Infections caused by non-dermatophyte molds, such as Fusarium spp. and yeasts, such as Candida spp., are particularly difficult to treat due to the formation of a mixed biofilm of the two species. Fusarium oxysporum is responsible for approximately 20% of human fusariosis, while Candida albicans is responsible for superficial mucosal and dermal infections and for disseminated bloodstream infections with a mortality rate above 40%. This study aims to investigate the interactions between C. albicans and F. oxysporum dual-species biofilm, considering variable formation conditions. Further, the ability of the WMR peptide, a modified version of myxinidin, to eradicate the mixed biofilm when used alone or in combination with fluconazole (FLC) was tested, and the efficacy of the combination of WMR and FLC at low doses was assessed, as well as its effect on the expression of some biofilm-related adhesin and hyphal regulatory genes. Finally, in order to confirm our findings in vivo and explore the synergistic effect of the two drugs, we utilized the Galleria mellonella infection model. We concluded that C. albicans negatively affects F. oxysporum growth in mixed biofilms. Combinatorial treatment by WMR and FLC significantly reduced the biomass and viability of both species in mature mixed biofilms, and these effects coincided with the reduced expression of biofilm-related genes in both fungi. Our results were confirmed in vivo since the synergistic antifungal activity of WMR and FLC increased the survival of infected larvae and reduced tissue invasion. These findings highlight the importance of drug combinations as an alternative treatment for C. albicans and F. oxysporum mixed biofilms.},
}
@article {pmid35745739,
year = {2022},
author = {Lattwein, KR and Beekers, I and Kouijzer, JJP and Leon-Grooters, M and Langeveld, SAG and van Rooij, T and van der Steen, AFW and de Jong, N and van Wamel, WJB and Kooiman, K},
title = {Dispersing and Sonoporating Biofilm-Associated Bacteria with Sonobactericide.},
journal = {Pharmaceutics},
volume = {14},
number = {6},
pages = {},
doi = {10.3390/pharmaceutics14061164},
pmid = {35745739},
issn = {1999-4923},
support = {805308/ERC_/European Research Council/International ; },
abstract = {Bacteria encased in a biofilm poses significant challenges to successful treatment, since both the immune system and antibiotics are ineffective. Sonobactericide, which uses ultrasound and microbubbles, is a potential new strategy for increasing antimicrobial effectiveness or directly killing bacteria. Several studies suggest that sonobactericide can lead to bacterial dispersion or sonoporation (i.e., cell membrane permeabilization); however, real-time observations distinguishing individual bacteria during and directly after insonification are missing. Therefore, in this study, we investigated, in real-time and at high-resolution, the effects of ultrasound-induced microbubble oscillation on Staphylococcus aureus biofilms, without or with an antibiotic (oxacillin, 1 μg/mL). Biofilms were exposed to ultrasound (2 MHz, 100-400 kPa, 100-1000 cycles, every second for 30 s) during time-lapse confocal microscopy recordings of 10 min. Bacterial responses were quantified using post hoc image analysis with particle counting. Bacterial dispersion was observed as the dominant effect over sonoporation, resulting from oscillating microbubbles. Increasing pressure and cycles both led to significantly more dispersion, with the highest pressure leading to the most biofilm removal (up to 83.7%). Antibiotic presence led to more variable treatment responses, yet did not significantly impact the therapeutic efficacy of sonobactericide, suggesting synergism is not an immediate effect. These findings elucidate the direct effects induced by sonobactericide to best utilize its potential as a biofilm treatment strategy.},
}
@article {pmid35745543,
year = {2022},
author = {Silva, V and Correia, E and Pereira, JE and González-Machado, C and Capita, R and Alonso-Calleja, C and Igrejas, G and Poeta, P},
title = {Exploring the Biofilm Formation Capacity in S. pseudintermedius and Coagulase-Negative Staphylococci Species.},
journal = {Pathogens (Basel, Switzerland)},
volume = {11},
number = {6},
pages = {},
doi = {10.3390/pathogens11060689},
pmid = {35745543},
issn = {2076-0817},
support = {SFRH/BD/137947/2018//Fundação para a Ciência e Tecnologia/ ; },
abstract = {The ability of biofilm formation seems to play an important role in the virulence of staphylococci. However, studies reporting biofilm formation of coagulase-negative staphylococci isolated from animals are still very scarce. Thus, we aimed to evaluate the biofilm-forming capacity of CoNS and S. pseudintermedius isolated from several animal species and to investigate the effect of conventional antimicrobials on biofilm reduction. A total of 35 S. pseudintermedius and 192 CoNS were included. Biofilm formation was accessed by the microtiter plate assay and the biofilms were stained by crystal violet. Association between biofilm formation and staphylococci species and antimicrobial resistance was also performed. Biofilm susceptibility testing was performed with tetracycline and amikacin at the minimum inhibitory concentration (MIC) and 10 × MIC. The metabolic activity of the biofilm cells after antimicrobial treatment was accessed by the XTT assay. All isolates formed biofilm, with S. urealyticus producing the most biofilm biomass and S. pseudintermedius producing the least biomass. There was a positive association between biofilm formation and multidrug resistance as well as resistance to individual antimicrobials. Neither tetracycline nor amikacin were able to eradicate the biofilm, not even at the highest concentration used. This study provides new insights into biofilm formation and the effects of antimicrobials on CoNS species.},
}
@article {pmid35745014,
year = {2022},
author = {Matchawong, A and Srisawat, C and Sangboonruang, S and Tharinjaroen, CS},
title = {The Ability of Nuclease-Resistant RNA Aptamer against Streptococcus suis Serotype 2, Strain P1/7 to Reduce Biofilm Formation In Vitro.},
journal = {Molecules (Basel, Switzerland)},
volume = {27},
number = {12},
pages = {},
doi = {10.3390/molecules27123894},
pmid = {35745014},
issn = {1420-3049},
support = {517803//National Research Council of Thailand/ ; //The Department of Medical Technology, Faculty of Associated Medical Sciences, Chiang Mai University/ ; },
abstract = {Streptococcus suis, a Gram-positive bacterium, is an important swine and human pathogen, with serotype 2 being the most prevalent strain found worldwide. Deafness, meningitis, and death (in severe cases) are observed in S. suis-infected cases. Development of the ligands that can bind to S. suis with high affinity and specificity could be beneficial for the diagnosis and treatment of S. suis infection. Herein, the nuclease-resistant RNA aptamers based on 2'-fluoropyrimidine modification against S. suis serotype 2, strain P1/7, were established using the cell- Systematic Evolution of Ligands by Exponential enrichment (SELEX) technique. One of the aptamers, R8-su12, could bind to the S. suis target strain as well as other S. suis serotypes, i.e., 1, 1/2, 9, and 14, but not to other bacteria tested, i.e., S. pneumoniae ATCC 49619, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 27853. Moreover, the R8-su12 RNA aptamer was also capable of inhibiting the biofilm formation of the S. suis target strain, making it potentially useful for the study of biofilm formation and the treatment of S. suis infection in humans and pigs in the future.},
}
@article {pmid35744757,
year = {2022},
author = {Sionov, RV and Steinberg, D},
title = {Targeting the Holy Triangle of Quorum Sensing, Biofilm Formation, and Antibiotic Resistance in Pathogenic Bacteria.},
journal = {Microorganisms},
volume = {10},
number = {6},
pages = {},
doi = {10.3390/microorganisms10061239},
pmid = {35744757},
issn = {2076-2607},
abstract = {Chronic and recurrent bacterial infections are frequently associated with the formation of biofilms on biotic or abiotic materials that are composed of mono- or multi-species cultures of bacteria/fungi embedded in an extracellular matrix produced by the microorganisms. Biofilm formation is, among others, regulated by quorum sensing (QS) which is an interbacterial communication system usually composed of two-component systems (TCSs) of secreted autoinducer compounds that activate signal transduction pathways through interaction with their respective receptors. Embedded in the biofilms, the bacteria are protected from environmental stress stimuli, and they often show reduced responses to antibiotics, making it difficult to eradicate the bacterial infection. Besides reduced penetration of antibiotics through the intricate structure of the biofilms, the sessile biofilm-embedded bacteria show reduced metabolic activity making them intrinsically less sensitive to antibiotics. Moreover, they frequently express elevated levels of efflux pumps that extrude antibiotics, thereby reducing their intracellular levels. Some efflux pumps are involved in the secretion of QS compounds and biofilm-related materials, besides being important for removing toxic substances from the bacteria. Some efflux pump inhibitors (EPIs) have been shown to both prevent biofilm formation and sensitize the bacteria to antibiotics, suggesting a relationship between these processes. Additionally, QS inhibitors or quenchers may affect antibiotic susceptibility. Thus, targeting elements that regulate QS and biofilm formation might be a promising approach to combat antibiotic-resistant biofilm-related bacterial infections.},
}
@article {pmid35744744,
year = {2022},
author = {Tuck, B and Watkin, E and Somers, A and Forsyth, M and Machuca, LL},
title = {Enhancing Biocide Efficacy: Targeting Extracellular DNA for Marine Biofilm Disruption.},
journal = {Microorganisms},
volume = {10},
number = {6},
pages = {},
doi = {10.3390/microorganisms10061227},
pmid = {35744744},
issn = {2076-2607},
support = {DP180101465//Australian Research Council/ ; },
abstract = {Biofilm formation is a global health, safety and economic concern. The extracellular composition of deleterious multispecies biofilms remains uncanvassed, leading to an absence of targeted biofilm mitigation strategies. Besides economic incentives, drive also exists from industry and research to develop and apply environmentally sustainable chemical treatments (biocides); especially in engineered systems associated with the marine environment. Recently, extracellular DNA (eDNA) was implicated as a critical structural polymer in marine biofilms. Additionally, an environmentally sustainable, multi-functional biocide was also introduced to manage corrosion and biofilm formation. To anticipate biofilm tolerance acquisition to chemical treatments and reduce biocide application quantities, the present research investigated eDNA as a target for biofilm dispersal and potential enhancement of biocide function. Results indicate that mature biofilm viability can be reduced by two-fold using reduced concentrations of the biocide alone (1 mM instead of the recommended 10 mM). Importantly, through the incorporation of an eDNA degradation stage, biocide function could be enhanced by a further ~90% (one further log reduction in viability). Biofilm architecture analysis post-treatment revealed that endonuclease targeting of the matrix allowed greater biocide penetration, leading to the observed viability reduction. Biofilm matrix eDNA is a promising target for biofilm dispersal and antimicrobial enhancement in clinical and engineered systems.},
}
@article {pmid35744740,
year = {2022},
author = {Kozień, Ł and Gallienne, E and Martin, O and Front, S and Strus, M and Heczko, P},
title = {PDIA, an Iminosugar Compound with a Wide Biofilm Inhibitory Spectrum Covering Both Gram-Positive and Gram-Negative Human Bacterial Pathogens.},
journal = {Microorganisms},
volume = {10},
number = {6},
pages = {},
doi = {10.3390/microorganisms10061222},
pmid = {35744740},
issn = {2076-2607},
support = {2018/31/B/NZ6/02443//National Science Center/ ; N N401 547040//National Science Center/ ; },
abstract = {Many difficult-to-treat human infections related to catheters and other indwelling devices are caused by bacteria residing in biofilms. One of the key properties of microorganisms residing in a biofilm is decreased susceptibility towards antimicrobial agents. Therefore, many different approaches have been researched to destroy or inhibit biofilm production by bacteria. Different iminosugars (IS) were reported to inhibit biofilm formation in S. mutans, S. aureus, and P. aeruginosa. The aim of this study was to look for a spectrum of the activity in one of these IS. The iminosugar PDIA beta-1-C-propyl-1,4-dideoxy-1,4-imino-L-arabinitol was tested in vitro at the same concentration against 30 different strains of the most important Gram-negative and Gram-positive human pathogens looking for their biofilm production and viability at different time intervals. It appeared that PDIA inhibited biofilm production of Enterobacter spp., P. aeruginosa, Enterococcus spp. and S. aureus in 8 h, and Klebsiella spp., Acinetobacter spp. and S.epidermidis in 24 h. PDIA caused no growth inhibition of the tested bacteria at a concentration of 0.9 mM. Our results indicate a broad-spectrum biofilm inhibitory activity of PDIA. which may be the basis for future application studies that will help in control of the associated device and biofilm-related infections caused by a wide spectrum of the causative agents.},
}
@article {pmid35744728,
year = {2022},
author = {Drożdż, K and Ochońska, D and Ścibik, Ł and Gołda-Cępa, M and Biegun, K and Brzychczy-Włoch, M},
title = {The Frequency of Occurrence of Resistance and Genes Involved in the Process of Adhesion and Accumulation of Biofilm in Staphylococcus aureus Strains Isolated from Tracheostomy Tubes.},
journal = {Microorganisms},
volume = {10},
number = {6},
pages = {},
doi = {10.3390/microorganisms10061210},
pmid = {35744728},
issn = {2076-2607},
support = {N41/DB5/000454//Jagiellonian University/ ; POWR.03.02.00-00- 468 I013/16//InterDokMed/ ; },
abstract = {Background: Bacterial biofilm on the surface of tracheostomy tubes (TTs) is a potential reservoir of potentially pathogenic bacteria, including S. aureus. For this reason, our study aimed to investigate biofilm production in vitro and the presence of icaAD and MSCRAMM genes in clinical S. aureus strains derived from TTs, with respect to antibiotic resistance and genetic variability. Methods: The clonality of the S. aureus strains was analyzed by the PFGE method. The assessment of drug resistance was based on the EUCAST recommendations. The isolates were evaluated for biofilm production by the microtiter plate method and the slime-forming ability was tested on Congo red agar (CRA). The presence of icaAD genes was investigated by PCR and MSCRAMM genes were detected by multiplex PCR. Results: A total of 60 patients were enrolled in the study. One TT was obtained from each patient (n = 60). Twenty-one TTs (35%) were colonized with S. aureus. A total of 24 strains were isolated as 3 patients showed colonization with 2 SA clones (as confirmed by PFGE). PFGE showed twenty-two unique molecular profiles. Two isolates (8%) turned out to be MRSA, but 50% were resistant to chloramphenicol, 25% to erythromycin and 8% to clindamycin (two cMLSB and four iMLSB phenotypes were detected). The microtiter plate method with crystal violet confirmed that 96% of the strains were biofilm formers. Representative strains were visualized by SEM. All isolates had clfAB, fnbA, ebpS and icaAD. Different MSCRAMM gene combinations were observed. Conclusions: the present study showed that the S. aureus isolated from the TTs has a high diversity of genotypes, a high level of antibiotic resistance and ability to produce biofilm.},
}
@article {pmid35744727,
year = {2022},
author = {Hou, J and Wang, L and Alm, M and Thomsen, P and Monsen, T and Ramstedt, M and Burmølle, M},
title = {Enhanced Antibiotic Tolerance of an In Vitro Multispecies Uropathogen Biofilm Model, Useful for Studies of Catheter-Associated Urinary Tract Infections.},
journal = {Microorganisms},
volume = {10},
number = {6},
pages = {},
doi = {10.3390/microorganisms10061207},
pmid = {35744727},
issn = {2076-2607},
support = {R324-2019-1775//Lundbeck Foundation/ ; },
abstract = {Catheter-associated urinary tract infections (CAUTI) are a common clinical concern as they can lead to severe, persistent infections or bacteremia in long-term catheterized patients. This type of CAUTI is difficult to eradicate, as they are caused by multispecies biofilms that may have reduced susceptibility to antibiotics. Many new strategies to tackle CAUTI have been proposed in the past decade, including antibiotic combination treatments, surface modification and probiotic usage. However, those strategies were mainly assessed on mono- or dual-species biofilms that hardly represent the long-term CAUTI cases where, normally, 2-4 or even more species can be involved. We developed a four-species in vitro biofilm model on catheters involving clinical strains of Escherichia coli, Pseudomonas aeruginosa, Klebsiella oxytoca and Proteus mirabilis isolated from indwelling catheters. Interspecies interactions and responses to antibiotics were quantitatively assessed. Collaborative as well as competitive interactions were found among members in our model biofilm and those interactions affected the individual species' abundances upon exposure to antibiotics as mono-, dual- or multispecies biofilms. Our study shows complex interactions between species during the assessment of CAUTI control strategies for biofilms and highlights the necessity of evaluating treatment and control regimes in a multispecies setting.},
}
@article {pmid35744683,
year = {2022},
author = {Kolodkin-Gal, I and Cohen-Cymberknoh, M and Zamir, G and Tsesis, I and Rosen, E},
title = {Targeting Persistent Biofilm Infections: Reconsidering the Topography of the Infection Site during Model Selection.},
journal = {Microorganisms},
volume = {10},
number = {6},
pages = {},
doi = {10.3390/microorganisms10061164},
pmid = {35744683},
issn = {2076-2607},
abstract = {The physiology of an organism in the environment reflects its interactions with the diverse physical, chemical, and biological properties of the surface. These principles come into consideration during model selection to study biofilm-host interactions. Biofilms are communities formed by beneficial and pathogenic bacteria, where cells are held together by a structured extracellular matrix. When biofilms are associated with a host, chemical gradients and their origins become highly relevant. Conventional biofilm laboratory models such as multiwall biofilm models and agar plate models poorly mimic these gradients. In contrast, ex vivo models possess the partial capacity to mimic the conditions of tissue-associated biofilm and a biofilm associated with a mineralized surface enriched in inorganic components, such as the human dentin. This review will highlight the progress achieved using these settings for two models of persistent infections: the infection of the lung tissue by Pseudomonas aeruginosa and the infection of the root canal by Enterococcus faecalis. For both models, we conclude that the limitations of the conventional in vitro systems necessitate a complimentary experimentation with clinically relevant ex vivo models during therapeutics development.},
}
@article {pmid35744681,
year = {2022},
author = {Carcione, D and Leccese, G and Conte, G and Rossi, E and Intra, J and Bonomi, A and Sabella, S and Moreo, M and Landini, P and Brilli, M and Paroni, M},
title = {Lack of Direct Correlation between Biofilm Formation and Antimicrobial Resistance in Clinical Staphylococcus epidermidis Isolates from an Italian Hospital.},
journal = {Microorganisms},
volume = {10},
number = {6},
pages = {},
doi = {10.3390/microorganisms10061163},
pmid = {35744681},
issn = {2076-2607},
abstract = {Staphylococcus epidermidis is an opportunistic pathogen and a frequent cause of nosocomial infections. In this work, we show that, among 51 S. epidermidis isolates from an Italian hospital, only a minority displayed biofilm formation, regardless of their isolation source (peripheral blood, catheter, or skin wounds); however, among the biofilm-producing isolates, those from catheters were the most efficient in biofilm formation. Interestingly, most isolates including strong biofilm producers displayed production levels of PIA (polysaccharide intercellular adhesin), the main S. epidermidis extracellular polysaccharide, similar to reference S. epidermidis strains classified as non-biofilm formers, and much lower than those classified as intermediate or high biofilm formers, possibly suggesting that high levels of PIA production do not confer a particular advantage for clinical isolates. Finally, while for the reference S. epidermidis strains the biofilm production clearly correlated with the decreased sensitivity to antibiotics, in particular, protein synthesis inhibitors, in our clinical isolates, such positive correlation was limited to tetracycline. In contrast, we observed an inverse correlation between biofilm formation and the minimal inhibitory concentrations for levofloxacin and teicoplanin. In addition, in growth conditions favoring PIA production, the biofilm-forming isolates showed increased sensitivity to daptomycin, clindamycin, and erythromycin, with increased tolerance to the trimethoprim/sulfamethoxazole association. The lack of direct correlation between the biofilm production and increased tolerance to antibiotics in S. epidermidis isolates from a clinical setting would suggest, at least for some antimicrobials, the possible existence of a trade-off between the production of biofilm determinants and antibiotic resistance.},
}
@article {pmid35744637,
year = {2022},
author = {Ma, PY and Chong, CW and Than, LTL and Sulong, AB and Ho, KL and Neela, VK and Sekawi, Z and Liew, YK},
title = {Impact of IsaA Gene Disruption: Decreasing Staphylococcal Biofilm and Alteration of Transcriptomic and Proteomic Profiles.},
journal = {Microorganisms},
volume = {10},
number = {6},
pages = {},
doi = {10.3390/microorganisms10061119},
pmid = {35744637},
issn = {2076-2607},
support = {FRGS/1/2018/SKK11/IMU/03/1//Fundamental Research Grant Scheme (FRGS)/ ; },
abstract = {Staphylococcus aureus expresses diverse proteins at different stages of growth. The immunodominant staphylococcal antigen A (IsaA) is one of the proteins that is constitutively produced by S. aureus during colonisation and infection. SACOL2584 (or isaA) is the gene that encodes this protein. It has been suggested that IsaA can hydrolyse cell walls, and there is still need to study isaA gene disruption to analyse its impact on staphylococcal phenotypes and on alteration to its transcription and protein profiles. In the present study, the growth curve in RPMI medium (which mimics human plasma), autolytic activity, cell wall morphology, fibronectin and fibrinogen adhesion and biofilm formation of S. aureus SH1000 (wildtype) was compared to that of S. aureus MS001 (isaA mutant). RNA sequencing and liquid chromatography-tandem mass spectrometry were carried out on samples of both S. aureus strains taken during the exponential growth phase, followed by bioinformatics analysis. Disruption of isaA had no obvious effect on the growth curve and autolysis ability or thickness of cell walls, but this study revealed significant strength of fibronectin adherence in S. aureus MS001. In particular, the isaA mutant formed less biofilm than S. aureus SH1000. In addition, proteomics and transcriptomics showed that the adhesin/biofilm-related genes and hemolysin genes, such as sasF, sarX and hlgC, were consistently downregulated with isaA gene disruption. The majority of the upregulated genes or proteins in S. aureus MS001 were pur genes. Taken together, this study provides insight into how isaA disruption changes the expression of other genes and has implications regarding biofilm formation and biological processes.},
}
@article {pmid35744626,
year = {2022},
author = {Qin, Y and Angelini, LL and Chai, Y},
title = {Bacillus subtilis Cell Differentiation, Biofilm Formation and Environmental Prevalence.},
journal = {Microorganisms},
volume = {10},
number = {6},
pages = {},
doi = {10.3390/microorganisms10061108},
pmid = {35744626},
issn = {2076-2607},
support = {1651732//National Science Foundation/ ; CAAS-ZDRW202009//Agricultural Science and Technology Innovation Program of CAAS, China/ ; },
abstract = {Bacillus subtilis is a soil-dwelling, spore-forming Gram-positive bacterium capable of cell differentiation. For decades, B. subtilis has been used as a model organism to study development of specialized cell types. In this minireview, we discuss cell differentiation in B. subtilis, covering both past research and recent progresses, and the role of cell differentiation in biofilm formation and prevalence of this bacterium in the environment. We review B. subtilis as a classic model for studies of endospore formation, and highlight more recent investigations on cell fate determination and generation of multiple cell types during biofilm formation. We present mechanistic details of how cell fate determination and mutually exclusive cell differentiation are regulated during biofilm formation.},
}
@article {pmid35744621,
year = {2022},
author = {Ballén, V and Cepas, V and Ratia, C and Gabasa, Y and Soto, SM},
title = {Clinical Escherichia coli: From Biofilm Formation to New Antibiofilm Strategies.},
journal = {Microorganisms},
volume = {10},
number = {6},
pages = {},
doi = {10.3390/microorganisms10061103},
pmid = {35744621},
issn = {2076-2607},
support = {PI19/00478//Instituto de Salud Carlos III/ ; REIPI RD12/0015/0013//Spanish Network for Research in Infectious Diseases from the Instituto de Salud Carlos III together with the European Development Regional Funds/ ; REIPI RD16/0016/0010//Spanish Network for Research in Infectious Diseases from the Instituto de Salud Carlos III together with the European Development Regional Funds/ ; 2014-2020//European Development Regional Fund "A way to achieve Europe" and operative program Intel-ligent Growth/ ; COLCIENCIAS Scholarship program N. 756//Ministerio de Ciencia, Tecnología e Innovación (Colombia)/ ; },
abstract = {Escherichia coli is one of the species most frequently involved in biofilm-related diseases, being especially important in urinary tract infections, causing relapses or chronic infections. Compared to their planktonic analogues, biofilms confer to the bacteria the capacity to be up to 1000-fold more resistant to antibiotics and to evade the action of the host's immune system. For this reason, biofilm-related infections are very difficult to treat. To develop new strategies against biofilms, it is important to know the mechanisms involved in their formation. In this review, the different steps of biofilm formation in E. coli, the mechanisms of tolerance to antimicrobials and new compounds and strategies to combat biofilms are discussed.},
}
@article {pmid35744599,
year = {2022},
author = {Lacotte, PA and Simons, A and Bouttier, S and Malet-Villemagne, J and Nicolas, V and Janoir, C},
title = {Inhibition of In Vitro Clostridioides difficile Biofilm Formation by the Probiotic Yeast Saccharomyces boulardii CNCM I-745 through Modification of the Extracellular Matrix Composition.},
journal = {Microorganisms},
volume = {10},
number = {6},
pages = {},
doi = {10.3390/microorganisms10061082},
pmid = {35744599},
issn = {2076-2607},
support = {No number//Biocodex, Gentilly, France/ ; },
abstract = {Clostridioides difficile is responsible for post-antibiotic diarrhea and most of the pseudomembranous colitis cases. Multiple recurrences, one of the major challenges faced in C. difficile infection (CDI) management, can be considered as chronic infections, and the role of biofilm formation in CDI recurrences is now widely considered. Therefore, we explored if the probiotic yeast Saccharomyces boulardii CNCM I-745 could impact the in vitro formation of C. difficile biofilm. Biomass staining and viable bacterial cell quantification showed that live S. boulardii exerts an antagonistic effect on the biofilm formation for the three C. difficile strains tested. Confocal laser scanning microscopy observation revealed a weakening and an average thickness reduction of the biofilm structure when C. difficile is co-incubated with S. boulardii, compared to the single-species bacterial biofilm structure. These effects, that were not detected with another genetically close yeast, S. cerevisiae, seemed to require direct contact between the probiotic yeast and the bacterium. Quantification of the extrapolymeric matrix components, as well as results obtained after DNase treatment, revealed a significant decrease of eDNA, an essential structural component of the C. difficile biofilm matrix, in the dual-species biofilm. This modification could explain the reduced cohesion and robustness of C. difficile biofilms formed in the presence of S. boulardii CNCM I-745 and be involved in S. boulardii clinical preventive effect against CDI recurrences.},
}
@article {pmid35744098,
year = {2022},
author = {De Francesco, F and Riccio, M and Jimi, S},
title = {Contribution of Topical Agents such as Hyaluronic Acid and Silver Sulfadiazine to Wound Healing and Management of Bacterial Biofilm.},
journal = {Medicina (Kaunas, Lithuania)},
volume = {58},
number = {6},
pages = {},
doi = {10.3390/medicina58060835},
pmid = {35744098},
issn = {1648-9144},
abstract = {Background and Objectives: Wound healing is commonly associated with critical bacterial colonization or bacterial infection, which induces prolonged inflammation, resulting in delayed re-epithelialization. An appropriate wound dressing requires a humid environment, which also functions as a barrier against bacterial contamination and will accelerate a regenerative response of the wound. Silver sulfadiazine (SSD) is used to prevent wound infection. Hyaluronic acid (HA) is an extracellular matrix component involved in tissue regeneration. This retrospective study was conducted to evaluate the effectiveness of cream and gauze pads based on hyaluronic acid at low molecular weight (200 kDa) and silver sulfadiazine 1% in the wound healing process. In addition, we examined SSD action on biofilms in vitro and on animal wounds, obtaining positive outcomes therefrom. Materials and Methods: We selected 80 patients with complicated chronic wounds of different etiologies, including diabetes mellitus (10), post-traumatic ulcers (45), burns (15), and superficial abrasion (10). Results: After 8 weeks, ulcer size was decreased in 95 ± 2% of the treated patients; a significant reduction in the inflammatory process was observed from day 14 onwards (p < 0.01 vs. baseline), considering improvement of the surrounding skin and reduction of the bacterial load. The SSD treatment decreased bacterial colony proliferation, both in planktonic state and in biofilm, in a dose-dependent manner on the wound but inhibited the development of tissue granulation at the highest dose (800 μg/wound). Conclusions: In conclusion, the combined action of SSD and HA is clinically effective in improving wound healing.},
}
@article {pmid35743833,
year = {2022},
author = {Gaglione, R and Pane, K and De Luca, M and Franzese, M and Arciello, A and Trama, F and Brancorsini, S and Salvatore, M and Illiano, E and Costantini, E},
title = {Novel Antimicrobial Strategies to Prevent Biofilm Infections in Catheters after Radical Cystectomy: A Pilot Study.},
journal = {Life (Basel, Switzerland)},
volume = {12},
number = {6},
pages = {},
doi = {10.3390/life12060802},
pmid = {35743833},
issn = {2075-1729},
abstract = {Catheter-associated infections in bladder cancer patients, following radical cystectomy or ureterocutaneostomy, are very frequent, and the development of antibiotic resistance poses great challenges for treating biofilm-based infections. Here, we characterized bacterial communities from catheters of patients who had undergone radical cystectomy for muscle-invasive bladder cancer. We evaluated the efficacy of conventional antibiotics, alone or combined with the human ApoB-derived antimicrobial peptide r(P)ApoBLAla, to treat ureteral catheter-colonizing bacterial communities on clinically isolated bacteria. Microbial communities adhering to indwelling catheters were collected during the patients' regular catheter change schedules (28 days) and extracted within 48 h. Living bacteria were characterized using selective media and biochemical assays. Biofilm growth and novel antimicrobial strategies were analyzed using confocal laser scanning microscopy. Statistical analyses confirmed the relevance of the biofilm reduction induced by conventional antibiotics (fosfomycin, ceftriaxone, ciprofloxacin, gentamicin, and tetracycline) and a well-characterized human antimicrobial peptide r(P)ApoBLAla (1:20 ratio, respectively). Catheters showed polymicrobial communities, with Enterobactericiae and Proteus isolates predominating. In all samples, we recorded a meaningful reduction in biofilms, in both biomass and thickness, upon treatment with the antimicrobial peptide r(P)ApoBLAla in combination with low concentrations of conventional antibiotics. The results suggest that combinations of conventional antibiotics and human antimicrobial peptides might synergistically counteract biofilm growth on ureteral catheters, suggesting novel avenues for preventing catheter-associated infections in patients who have undergone radical cystectomy and ureterocutaneostomy.},
}
@article {pmid35742906,
year = {2022},
author = {Jahan, F and Chinni, SV and Samuggam, S and Reddy, LV and Solayappan, M and Su Yin, L},
title = {The Complex Mechanism of the Salmonella&amp;nbsp;typhi Biofilm Formation That Facilitates Pathogenicity: A Review.},
journal = {International journal of molecular sciences},
volume = {23},
number = {12},
pages = {},
doi = {10.3390/ijms23126462},
pmid = {35742906},
issn = {1422-0067},
support = {FRGS/1/2018/STG03/AIMST/02/2//Ministry of Higher Education/ ; },
abstract = {Salmonella enterica serovar Typhi (S. typhi) is an intracellular pathogen belonging to the Enterobacteriaceae family, where biofilm (aggregation and colonization of cells) formation is one of their advantageous traits. Salmonella typhi is the causative agent of typhoid fever in the human body and is exceptionally host specific. It is transmitted through the fecal-oral route by consuming contaminated food or water. This subspecies is quite intelligent to evade the innate detection and immune response of the host body, leading to systemic dissemination. Consequently, during the period of illness, the gallbladder becomes a harbor and may develop antibiotic resistance. Afterwards, they start contributing to the continuous damage of epithelium cells and make the host asymptomatic and potential carriers of this pathogen for an extended period. Statistically, almost 5% of infected people with Salmonella typhi become chronic carriers and are ready to contribute to future transmission by biofilm formation. Biofilm development is already recognized to link with pathogenicity and plays a crucial role in persistency within the human body. This review seeks to discuss some of the crucial factors related to biofilm development and its mechanism of interaction causing pathogenicity. Understanding the connections between these things will open up a new avenue for finding therapeutic approaches to combat pathogenicity.},
}
@article {pmid35742863,
year = {2022},
author = {Rahman, MA and Amirkhani, A and Chowdhury, D and Mempin, M and Molloy, MP and Deva, AK and Vickery, K and Hu, H},
title = {Proteome of Staphylococcus aureus Biofilm Changes Significantly with Aging.},
journal = {International journal of molecular sciences},
volume = {23},
number = {12},
pages = {},
doi = {10.3390/ijms23126415},
pmid = {35742863},
issn = {1422-0067},
abstract = {Staphylococcus aureus is a notorious biofilm-producing pathogen that is frequently isolated from implantable medical device infections. As biofilm ages, it becomes more tolerant to antimicrobial treatment leading to treatment failure and necessitating the costly removal of infected devices. In this study, we performed in-solution digestion followed by TMT-based high-throughput mass spectrometry and investigated what changes occur in the proteome of S. aureus biofilm grown for 3-days and 12-days in comparison with 24 h planktonic. It showed that proteins associated with biosynthetic processes, ABC transporter pathway, virulence proteins, and shikimate kinase pathway were significantly upregulated in a 3-day biofilm, while proteins associated with sugar transporter, degradation, and stress response were downregulated. Interestingly, in a 3-day biofilm, we observed numerous proteins involved in the central metabolism pathways which could lead to biofilm growth under diverse environments by providing an alternative metabolic route to utilize energy. In 12-day biofilms, proteins associated with peptidoglycan biosynthesis, sugar transporters, and stress responses were upregulated, whereas proteins associated with ABC transporters, DNA replication, and adhesion proteins were downregulated. Gene Ontology analysis revealed that more proteins are involved in metabolic processes in 3dwb compared with 12dwb. Furthermore, we observed significant variations in the formation of biofilms resulting from changes in the level of metabolic activity in the different growth modes of biofilms that could be a significant factor in S. aureus biofilm maturation and persistence. Collectively, potential marker proteins were identified and further characterized to understand their exact role in S. aureus biofilm development, which may shed light on possible new therapeutic regimes in the treatment of biofilm-related implant-associated infections.},
}
@article {pmid35740385,
year = {2022},
author = {Shaghayegh, G and Cooksley, C and Ramezanpour, M and Wormald, PJ and Psaltis, AJ and Vreugde, S},
title = {Chronic Rhinosinusitis, S. aureus Biofilm and Secreted Products, Inflammatory Responses, and Disease Severity.},
journal = {Biomedicines},
volume = {10},
number = {6},
pages = {},
doi = {10.3390/biomedicines10061362},
pmid = {35740385},
issn = {2227-9059},
abstract = {Chronic rhinosinusitis (CRS) is a persistent inflammation of the nasal cavity and paranasal sinuses associated with tissue remodelling, dysfunction of the sinuses' natural defence mechanisms, and induction of different inflammatory clusters. The etiopathogenesis of CRS remains elusive, and both environmental factors, such as bacterial biofilms and the host's general condition, are thought to play a role. Bacterial biofilms have significant clinical relevance due to their potential to cause resistance to antimicrobial therapy and host defenses. Despite substantial medical advances, some CRS patients suffer from recalcitrant disease that is unresponsive to medical and surgical treatments. Those patients often have nasal polyps with tissue eosinophilia, S. aureus-dominant mucosal biofilm, comorbid asthma, and a severely compromised quality of life. This review aims to summarise the contemporary knowledge of inflammatory cells/pathways in CRS, the role of bacterial biofilm, and their impact on the severity of the disease. Here, an emphasis is placed on S. aureus biofilm and its secreted products. A better understanding of these factors might offer important diagnostic and therapeutic perceptions for recalcitrant disease.},
}
@article {pmid35740208,
year = {2022},
author = {Radunovic, M and Barac, M and Kuzmanovic Pficer, J and Pavlica, D and Jovanovic, A and Pucar, A and Petrovic, S},
title = {Antifungal Susceptibility of Candida albicans Isolated from Tongue and Subgingival Biofilm of Periodontitis Patients.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {11},
number = {6},
pages = {},
doi = {10.3390/antibiotics11060802},
pmid = {35740208},
issn = {2079-6382},
support = {451-03-68/2022-14/200129//the Ministry of Education, Science and Technological De-velopment, Republic of Serbia/ ; },
abstract = {The subgingival biofilm, as the most complex microbial community, has been proven to be reservoir of Candida spp. The main concept of this study was to investigate if there is a difference between the sensitivity of Candida albicans (C. albicans) isolated from tongue and subgingival areas of periodontitis patients to antifungal agents. The aim of the study was to determine: (1) the distribution of different Candida species in the tongue and subgingival samples of periodontitis patients; (2) the susceptibility of Candida albicans strains from tongue and subgingival biofilm to the effects of commonly used antifungal agents: fluconazole, amphotericin B and itraconazole; (3) the correlation between the susceptibility of Candida albicans and clinical periodontal parameters. Tongue and subgingival biofilm samples of periodontitis subjects (N = 163) were examined. Susceptibility was tested when the same Candida species was isolated from both sites (17 subjects). Candida spp. were isolated in 23.3% of tongue and 21.5% of the subgingival samples. All isolates were susceptible to amphotericin B, while 64.71% of tongue and 52.94% of subgingival isolates were susceptible to fluconazole. A low frequency of itraconazole susceptibility was observed for tongue (17.64%) and subgingival isolates (11.76%). The correlations between full-mouth plaque score and Minimal Inhibitory Concentration (MIC) for tongue isolates were strongly positive for all antimycotics. Positive correlation was also observed between moderate periodontal destruction and MICs for tongue and subgingival isolates. The susceptibility of C. albicans to antifungals correlate with oral hygiene and moderate periodontal destruction. There is no difference in antifungal susceptibility between tongue and subgingival isolates.},
}
@article {pmid35740178,
year = {2022},
author = {Silva, V and Correia, E and Pereira, JE and González-Machado, C and Capita, R and Alonso-Calleja, C and Igrejas, G and Poeta, P},
title = {Biofilm Formation of Staphylococcus aureus from Pets, Livestock, and Wild Animals: Relationship with Clonal Lineages and Antimicrobial Resistance.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {11},
number = {6},
pages = {},
doi = {10.3390/antibiotics11060772},
pmid = {35740178},
issn = {2079-6382},
support = {SFRH/BD/137947/2018//Fundação para a Ciência e Tecnologia/ ; },
abstract = {This study aimed to compare the biofilm formation ability of Staphylococcus aureus isolated from a wide range of animals and study the association between biofilm formation and antimicrobial resistance and genetic lineages. A total of 214 S. aureus strains isolated from pets, livestock, and wild animals were evaluated regarding their ability to form biofilms by the microtiter biofilm assay and their structure via confocal scanning laser microscopy. Statistical analysis was used to find an association between biofilm formation and antimicrobial resistance, multidrug resistance, sequence types (STs), spa and agr-types of the isolates. The antimicrobial susceptibility of 24 h-old biofilms was assessed against minimum inhibitory concentrations (MIC) and 10× MIC of amikacin and tetracycline, and the biomass reduction was measured. The metabolic activity of biofilms after antimicrobial treatment was evaluated by the XTT assay. All isolates were had the ability to form biofilms. Yet, significant differences in biofilm biomass production were detected among animal species. Multidrug resistance had a positive association with biofilm formation as well as methicillin-resistance. Significant differences were also detected among the clonal lineages of the isolates. Both tetracycline and amikacin were able to significantly reduce the biofilm mass. However, none of the antimicrobials were able to eradicate the biofilm at the maximum concentration used. Our results provide important information on the biofilm-forming capacity of animal-adapted S. aureus isolates, which may have potential implications for the development of new biofilm-targeted therapeutics.},
}
@article {pmid35740134,
year = {2022},
author = {Takenaka, S and Sotozono, M and Ohkura, N and Noiri, Y},
title = {Evidence on the Use of Mouthwash for the Control of Supragingival Biofilm and Its Potential Adverse Effects.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {11},
number = {6},
pages = {},
doi = {10.3390/antibiotics11060727},
pmid = {35740134},
issn = {2079-6382},
support = {19H03958H//Japan Society for the Promotion of Science/ ; },
abstract = {Antimicrobial mouthwash improves supragingival biofilm control when used in conjunction with mechanical removal as part of an oral hygiene routine. Mouthwash is intended to suppress bacterial adhesion during biofilm formation processes and is not aimed at mature biofilms. The most common evidence-based effects of mouthwash on the subgingival biofilm include the inhibition of biofilm accumulation and its anti-gingivitis property, followed by its cariostatic activities. There has been no significant change in the strength of the evidence over the last decade. A strategy for biofilm control that relies on the elimination of bacteria may cause a variety of side effects. The exposure of mature oral biofilms to mouthwash is associated with several possible adverse reactions, such as the emergence of resistant strains, the effects of the residual structure, enhanced pathogenicity following retarded penetration, and ecological changes to the microbiota. These concerns require further elucidation. This review aims to reconfirm the intended effects of mouthwash on oral biofilm control by summarizing systematic reviews from the last decade and to discuss the limitations of mouthwash and potential adverse reactions to its use. In the future, the strategy for oral biofilm control may shift to reducing the biofilm by detaching it or modulating its quality, rather than eliminating it, to preserve the benefits of the normal resident oral microflora.},
}
@article {pmid35740122,
year = {2022},
author = {Babosan, A and Gaschet, M and Muggeo, A and Jové, T and Skurnik, D and Ploy, MC and de Champs, C and Reffuveille, F and Guillard, T},
title = {A qnrD-Plasmid Promotes Biofilm Formation and Class 1 Integron Gene Cassette Rearrangements in Escherichia coli.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {11},
number = {6},
pages = {},
doi = {10.3390/antibiotics11060715},
pmid = {35740122},
issn = {2079-6382},
abstract = {Bacteria within biofilms may be exposed to sub-minimum inhibitory concentrations (sub-MICs) of antibiotics. Cell-to-cell contact within biofilms facilitates horizontal gene transfers and favors induction of the SOS response. Altogether, it participates in the emergence of antibiotic resistance. Aminoglycosides at sub-MICs can induce the SOS response through NO accumulation in E. coli carrying the small plasmid with the quinolone resistance qnrD gene (pDIJ09-518a). In this study, we show that in E. coli pDIJ09-518a, the SOS response triggered by sub-MICs of aminoglycosides has important consequences, promoting genetic rearrangement in class 1 integrons and biofilm formation. We found that the integrase expression was increased in E. coli carrying pDIJ09-518a in the presence of tobramycin, which was not observed for the WT isogenic strain that did not carry the qnrD-plasmid. Moreover, we showed that biofilm production was significantly increased in E. coli WT/pDIJ09-518a compared to the WT strain. However, such a higher production was decreased when the Hmp-NO detoxification pathway was fully functional by overexpressing Hmp. Our results showing that a qnrD-plasmid can promote biofilm formation in E. coli and potentiate the acquisition and spread of resistance determinants for other antibiotics complicate the attempts to counteract antibiotic resistance and prevention of biofilm development even further. We anticipate that our findings emphasize the complex challenges that will impact the decisions about antibiotic stewardship, and other decisions related to retaining antibiotics as effective drugs and the development of new drugs.},
}
@article {pmid35740119,
year = {2022},
author = {Necel, A and Bloch, S and Topka-Bielecka, G and Janiszewska, A and Łukasiak, A and Nejman-Faleńczyk, B and Węgrzyn, G},
title = {Synergistic Effects of Bacteriophage vB_Eco4-M7 and Selected Antibiotics on the Biofilm Formed by Shiga Toxin-Producing Escherichia coli.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {11},
number = {6},
pages = {},
doi = {10.3390/antibiotics11060712},
pmid = {35740119},
issn = {2079-6382},
support = {D000.MN.05.20//University of Gdańsk/ ; 531-D020-D242-21//University of Gdańsk/ ; },
abstract = {Apart from antibiotic resistance of pathogenic bacteria, the formation of biofilms is a feature that makes bacterial infections especially difficulty to treat. Shiga toxin-producing Escherichia coli (STEC) strains are dangerous pathogens, causing severe infections in humans, and capable of biofilm production. We have reported previously the identification and characterization of the vB_Eco4-M7 bacteriophage, infecting various STEC strains. It was suggested that this phage might be potentially used in phage therapy against these bacteria. Here, we tested the effects of vB_Eco4-M7 alone or in a phage cocktail with another STEC-infecting phage, and/or in a combination with different antibiotics (ciprofloxacin and rifampicin) on biofilm formed by a model STEC strain, named E. coli O157:H7 (ST2-8624). The vB_Eco4-M7 phage appeared effective in anti-biofilm action in all these experimental conditions (2-3-fold reduction of the biofilm density, and 2-3 orders of magnitude reduction of the number of bacterial cells). However, the highest efficiency in reducing a biofilm's density and number of bacterial cells was observed when phage infection preceded antibiotic treatment (6-fold reduction of the biofilm density, and 5-6 orders of magnitude reduction of the number of bacterial cells). Previous reports indicated that the use of antibiotics to treat STEC-caused infections might be dangerous due to the induction of Shiga toxin-converting prophages from bacterial genomes under stress conditions caused by antibacterial agents. We found that ciprofloxacin was almost as efficient in inducing prophages from the E. coli O15:H7 (ST2-8624) genome as a classical inducer, mitomycin C, while no detectable prophage induction could be observed in rifampicin-treated STEC cells. Therefore, we conclude the latter antibiotic or similarly acting compounds might be candidate(s) as effective and safe drug(s) when used in combination with phage therapy to combat STEC-mediated infections.},
}
@article {pmid35739732,
year = {2022},
author = {Ji, H and Hu, H and Tang, Q and Kang, X and Liu, X and Zhao, L and Jing, R and Wu, M and Li, G and Zhou, X and Liu, J and Wang, Q and Cong, H and Wu, L and Qin, Y},
title = {Precisely controlled and deeply penetrated micro-nano hybrid multifunctional motors with enhanced antibacterial activity against refractory biofilm infections.},
journal = {Journal of hazardous materials},
volume = {436},
number = {},
pages = {129210},
doi = {10.1016/j.jhazmat.2022.129210},
pmid = {35739732},
issn = {1873-3336},
abstract = {The biofilm resistance of microorganisms has severe economic and environmental implications, especially the contamination of facilities associated with human life, including medical implants, air-conditioning systems, water supply systems, and food-processing equipment, resulting in the prevalence of infectious diseases. Once bacteria form biofilms, their antibiotic resistance can increase by 10-1,000-fold, posing a great challenge to the treatment of related diseases. In order to overcome the contamination of bacterial biofilm, destroying the biofilm's matrix so as to solve the penetration depth dilemma of antibacterial agents is the most effective way. Here, a magnetically controlled multifunctional micromotor was developed by using H2O2 as the fuel and MnO2 as the catalyst to treat bacterial biofilm infection. In the presence of H2O2, the as-prepared motors could be self-propelled by the generated oxygen microbubbles. Thereby, the remotely controlled motors could drill into the EPS of biofilm and disrupt them completely with the help of bubbles. Finally, the generated highly toxic •OH could efficiently kill the unprotected bacteria. This strategy combined the mechanical damage, highly toxic •OH, and precise magnetic guidance in one system, which could effectively eliminate biologically infectious fouling in microchannels within 10 min, possessing a wide range of practical application prospects especially in large scale and complex infection sites.},
}
@article {pmid35739657,
year = {2022},
author = {Geng, N and Xia, Y and Lu, D and Bai, Y and Zhao, Y and Wang, H and Ren, L and Xu, C and Hua, E and Sun, G and Chen, X},
title = {The bacterial community structure in epiphytic biofilm on submerged macrophyte Potamogetom crispus L. and its contribution to heavy metal accumulation in an urban industrial area in Hangzhou.},
journal = {Journal of hazardous materials},
volume = {430},
number = {},
pages = {128455},
doi = {10.1016/j.jhazmat.2022.128455},
pmid = {35739657},
issn = {1873-3336},
abstract = {Submerged macrophytes and their epiphytic biofilms are important media for metal transport/transformation in aquatic environment. However, the bacterial community structure and the contribution of the epiphytic biofilm to the heavy metal accumulation remain unclear. Therefore, in this study, water, sediment, submerged macrophyte (Potamogeton crispus L.) and its epiphytic biofilm samples in three sites of the moat in the industrial area of Hangzhou were collected for analyzing. The bacterial community structure was significantly impacted by the TN concentrations, and Genus Aeromonas (24.5-41.8%), Acinetobacter (16.2-29.8%) and Pseudomonas (12.6-23.6%) dominated in all epiphytic biofilm samples, which had the heavy metal pollutant resistibility. The contents of Cr in biofilms (7.4-8.3 mg/kg, DW) were significantly higher than those in leaves (1.0-2.4 mg/kg, DW), while the contents of Cu (11.0-13.9 mg/kg, DW) in leaves were significantly higher than those in biofilms (0.7-3.9 mg/kg, DW) in all the three sites. The BCF values of metals in the biofilm were followed the order of YF < IC < ETS. The results indicated that the epiphytic biofilm had positive effects on the metal bioaccumulation, and the metal accumulation ability increased with the hydrodynamic forces. Bioaccumulation by the epiphytic biofilm may be an effective way for metal (especially Cr) remediation.},
}
@article {pmid35739327,
year = {2022},
author = {Soliemani, O and Salimi, F and Rezaei, A},
title = {Characterization of exopolysaccharide produced by probiotic Enterococcus durans DU1 and evaluation of its anti-biofilm activity.},
journal = {Archives of microbiology},
volume = {204},
number = {7},
pages = {419},
pmid = {35739327},
issn = {1432-072X},
abstract = {Exopolysaccharides (EPS) produced by lactic acid bacteria are complicated polymers with industrial applications. LAB were isolated, screened for EPS production, and their probiotic properties determined. The anti-biofilm activity of EPS was investigated. Safety of EPS-producing isolate was investigated and it was molecularly identified through 16S rRNA sequencing. Finally, anti-biofilm and emulsification activity of EPS was studied and it was characterized using FT-IR, TGA, 1H-NMR, DLS and HPLC. Thirteen LAB were isolated from dairy products. They showed probiotic characteristics like acid resistance (0-6.51 CFU ml-1) hydrophobicity (8-54.04%), autoaggregation (0% [t = 2 h]-99.8% [t = 24 h]) and coaggregation with food borne pathogens. Among them, Enterococcus durans DU1 had ability to produce EPS. EPS of Enterococcus durans DU1 showed antibiofilm activity against Y. enterocolitica (24.06-51.36%), S. aureus (12.33-49.6%), and B. cereus (11.66-27.16%). FT-IR showed this EPS had characteristic absorption peaks due to the presence of the pyran ring of sugars. 1H NMR showed that EPS has N-acetyl, methyl, and alkyl groups in its structure. The HPLC analysis showed that EPS is a heteropolysaccharide and consists of sucrose, glucose, and fructose. EPS showed significant thermal stability (20% weight loss) under 300 °C and zeta potential of - 18.1 mV. This EPS can be used in the food industry with no adverse effect on consumers.},
}
@article {pmid35738989,
year = {2022},
author = {Hernandez-Cuellar, E and Guerrero-Barrera, AL and Avelar-Gonzalez, FJ and Díaz, JM and Santiago, AS and Chávez-Reyes, J and Poblano-Sánchez, E},
title = {Characterization of Candida albicans and Staphylococcus aureus polymicrobial biofilm on different surfaces.},
journal = {Revista iberoamericana de micologia},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.riam.2022.04.001},
pmid = {35738989},
issn = {2173-9188},
abstract = {BACKGROUND: Staphylococcus aureus and Candida albicans have been co-isolated from biofilm-associated diseases such as denture stomatitis, periodontitis, and burn wound infections, as well as from medical devices. However, the polymicrobial biofilm of both microorganisms has not been fully characterized.<br><br>AIMS: To characterize the polymicrobial biofilm of C. albicans and S. aureus in terms of microbial density, synergy, composition, structure, and stability against antimicrobials and chemical agents.<br><br>METHODS: Crystal violet assay was used to measure the biofilm formation. Scanning electron microscopy and confocal microscopy were used to analyze the structure and chemical composition of the biofilms, respectively.<br><br>RESULTS: Supplemented media with fetal bovine serum (FBS) decreased the biofilm formation of S. aureus and the polymicrobial biofilm. For C. albicans, depending on the culture media, the addition of glucose or FBS had a positive effect in biofilm formation. FBS decreased the adhesion to polystyrene wells for both microorganisms. Supplementing the media with glucose and FBS enhanced the growth of C. albicans and S. aureus, respectively. It seems that C. albicans contributes the most to the adhesion process and to the general structure of the biofilms on all the surfaces tested, including a catheter model. Interestingly, S. aureus showed a great adhesion capacity to the surface of C. albicans in the biofilms. Proteins and β-1,6-linked polysaccharides seem to be the most important molecules in the polymicrobial biofilm.<br><br>CONCLUSIONS: The polymicrobial biofilm had a complex structure, with C. albicans serving as a scaffold where S. aureus adheres, preferentially to the hyphal form of the fungus. Detection of polymicrobial infections and characterization of biofilms will be necessary in the future to provide a better treatment.},
}
@article {pmid35736669,
year = {2022},
author = {Sharma, A and Vashistt, J and Shrivastava, R},
title = {Mycobacterium fortuitum fabG4 knockdown studies: Implication as pellicle and biofilm specific drug target.},
journal = {Journal of basic microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1002/jobm.202200230},
pmid = {35736669},
issn = {1521-4028},
abstract = {The fatty acid biosynthesis pathway is crucial for the formation of the mycobacterial cell envelope. The fatty acid synthase type-II (FAS-II) components are attractive targets for designing anti-biofilm inhibitors. Literature review, bioinformatics analysis, cloning, and sequencing led to the identification of a novel Mycobacterium fortuitum FAS-II gene MFfabG4 which interacts with mycobacterial proteins involved in biofilm formation. A manually curated M. fortuitum fatty acid biosynthesis pathway has been proposed exploiting functional studies from the Kyoto Encyclopedia of Genes and Genomes and Mycobrowser databases for MFFabG4. M. fortuitum MFfabG4 knockdown strain (FA) was constructed and validated by quantitative polymerase chain reaction. The FA strain displayed unstructured smooth colony architecture, correlating with decreased pathogenicity and virulence. MFfabG4 knockdown resulted in diminished pellicle and attenuated biofilm formation, along with impaired sliding motility, and reduced cell sedimentation. The FA strain showed lowered cell surface hydrophobicity, indicating attenuation in M. fortuitum intracellular infection-causing ability. Stress survival studies showed the requirement of MFfabG4 for survival in a nutrient-starved environment. The results indicate that MFfabG4 maintains the physiology of the cell envelope and is required for the formation of M. fortuitum pellicle and biofilm. The study corroborates the role of MFfabG4 as a pellicle- and biofilm-specific drug target and a potential diagnostic marker for M. fortuitum and related pathogenic mycobacteria.},
}
@article {pmid35736039,
year = {2022},
author = {Souza, SO and Raposo, BL and Sarmento-Neto, JF and Rebouças, JS and Macêdo, DPC and Figueiredo, RCBQ and Santos, BS and Freitas, AZ and Cabral Filho, PE and Ribeiro, MS and Fontes, A},
title = {Photoinactivation of Yeast and Biofilm Communities of Candida albicans Mediated by ZnTnHex-2-PyP4+ Porphyrin.},
journal = {Journal of fungi (Basel, Switzerland)},
volume = {8},
number = {6},
pages = {},
doi = {10.3390/jof8060556},
pmid = {35736039},
issn = {2309-608X},
support = {219677_Z_19_Z/WT_/Wellcome Trust/United Kingdom ; 406450/2021-8//National Council for Scientific and Technological Development/ ; APQ-0573-2.09/18//Fundação de Amparo à Ciência e Tecnologia de Pernambuco/ ; 2018/20226-7//São Paulo Research Foundation/ ; 465763/2014-6//Instituto Nacional de Ciência e Tecnologia de Fotônica (INCT-INFo)/ ; },
abstract = {Candida albicans is the main cause of superficial candidiasis. While the antifungals available are defied by biofilm formation and resistance emergence, antimicrobial photodynamic inactivation (aPDI) arises as an alternative antifungal therapy. The tetracationic metalloporphyrin Zn(II) meso-tetrakis(N-n-hexylpyridinium-2-yl)porphyrin (ZnTnHex-2-PyP4+) has high photoefficiency and improved cellular interactions. We investigated the ZnTnHex-2-PyP4+ as a photosensitizer (PS) to photoinactivate yeasts and biofilms of C. albicans strains (ATCC 10231 and ATCC 90028) using a blue light-emitting diode. The photoinactivation of yeasts was evaluated by quantifying the colony forming units. The aPDI of ATCC 90028 biofilms was assessed by the MTT assay, propidium iodide (PI) labeling, and scanning electron microscopy. Mammalian cytotoxicity was investigated in Vero cells using MTT assay. The aPDI (4.3 J/cm2) promoted eradication of yeasts at 0.8 and 1.5 µM of PS for ATCC 10231 and ATCC 90028, respectively. At 0.8 µM and same light dose, aPDI-treated biofilms showed intense PI labeling, about 89% decrease in the cell viability, and structural alterations with reduced hyphae. No considerable toxicity was observed in mammalian cells. Our results introduce the ZnTnHex-2-PyP4+ as a promising PS to photoinactivate both yeasts and biofilms of C. albicans, stimulating studies with other Candida species and resistant isolates.},
}
@article {pmid35735992,
year = {2022},
author = {Bulock, LL and Ahn, J and Shinde, D and Pandey, S and Sarmiento, C and Thomas, VC and Guda, C and Bayles, KW and Sadykov, MR},
title = {Interplay of CodY and CcpA in Regulating Central Metabolism and Biofilm Formation in Staphylococcus aureus.},
journal = {Journal of bacteriology},
volume = {},
number = {},
pages = {e0061721},
doi = {10.1128/jb.00617-21},
pmid = {35735992},
issn = {1098-5530},
abstract = {Staphylococcus aureus is a medically important pathogen with high metabolic versatility allowing it to infect various niches within a host. S. aureus utilizes two major transcriptional regulators, namely, CodY and CcpA, to remodel metabolic and virulence gene expression in response to changing environmental conditions. Previous studies revealed that inactivation of either codY or ccpA has a pronounced impact on different aspects of staphylococcal physiology and pathogenesis. To determine the contribution and interplay of these two regulators in modulating central metabolism, virulence, and biofilm development, we constructed and characterized the codY ccpA double mutant in S. aureus UAMS-1. In line with previous studies, we found that CcpA and CodY control the cellular metabolic status by altering carbon flux through the central and overflow metabolic pathways. Our results demonstrate that ccpA inactivation impairs biofilm formation and decreases incorporation of extracellular DNA (eDNA) into the biofilm matrix, whereas disrupting codY resulted in a robust structured biofilm tethered together with eDNA and polysaccharide intercellular adhesin (PIA). Interestingly, inactivation of both codY and ccpA decreases biofilm biomass and reduces eDNA release in the double mutant. Compared with the inactivation of codY, the codY ccpA mutant did not overexpress toxins but maintained overexpression of amino acid metabolism pathways. Furthermore, the codY ccpA mutant produced large amounts of PIA, in contrast to the wild-type strain and ccpA mutant. Combined, the results of this study suggest that the coordinated action of CodY and CcpA modulate central metabolism, virulence gene expression, and biofilm-associated genes to optimize growth on preferred carbon sources until starvation sets in. IMPORTANCE Staphylococcus aureus is a leading cause of biofilm-associated infections, including infective endocarditis, worldwide. A greater understanding of metabolic forces driving biofilm formation in S. aureus is essential for the identification of novel therapeutic targets and for the development of new strategies to combat this medically important pathogen. This study characterizes the interplay and regulation of central metabolism and biofilm development by two global transcriptional regulators, CodY and CcpA. We found that the lack of CcpA and/or CodY have different impacts on intracellular metabolic status leading to a formation of morphologically altered biofilms. Overall, the results of this study provide new insights into our understanding of metabolism-mediated regulation of biofilm development in S. aureus.},
}
@article {pmid35735075,
year = {2022},
author = {Pamukçu, A and Erdoğan, N and Şen Karaman, D},
title = {Polyethylenimine-grafted mesoporous silica nanocarriers markedly enhance the bactericidal effect of curcumin against Staphylococcus aureus biofilm.},
journal = {Journal of biomedical materials research. Part B, Applied biomaterials},
volume = {},
number = {},
pages = {},
doi = {10.1002/jbm.b.35108},
pmid = {35735075},
issn = {1552-4981},
support = {//Council of Higher Education 100/2000 doctoral scholarship/ ; //The Turkish Scientific and Technological Research Council 2211-A BIDEB doctoral scholarship/ ; 319S024//The Turkish Scientific and Technological Research Council/ ; },
abstract = {The recalcitrant nature of biofilms makes biofilm-associated infections difficult to treat in modern medicine. Biofilms have a high vulnerability to antibiotics and a limited repertoire of antibiotics could act on matured biofilms. This issue has resulted in a gradual paradigm shift in drug discovery and therapy, with anti-biofilm compounds being sought alongside new drug carriers. A potential solution to biofilm-associated infections is to employ antibiofilm treatments, which can attack biofilms from many fronts. Nanocarriers are promising in this regard because they can be entrapped within biofilm matrix, target biofilm matrix, and provide local drug delivery to inhibit biofilm formation. In this study, curcumin as an herbal extract was loaded onto hyperbranched polyethylenimine-grafted mesoporous silica nanoparticles (F-MSN-PEI/Cur) and antibiofilm investigations were performed. The F-MSN-PEI/Cur design has the potential to repurpose curcumin as an antibiofilm agent by increasing its solubility and lowering the required doses for the destruction of matured biofilms as well as suppressing biofilm development. Using imaging and spectroscopic techniques, we assessed the interaction of F-MSN-PEI/Cur with Staphylococcus aureus bacterial cells and determined the impact of F-MSN-PEI/Cur on eradicating matured biofilms and suppressing biofilm development. The F-MSN-PEI/Cur design is highly cytocompatible, as observed by the cytotoxicity screening investigations on L929 mouse fibroblast cell line. Our findings show that F-MSN-PEI/Cur design reduces the bacterial cell viability, inhibits biofilm formation, and induces biofilm eradication, which is attributed to F-MSN-PEI/Cur design having the potential to repurpose the antibiofilm activity of curcumin-herbal extract.},
}
@article {pmid35733961,
year = {2022},
author = {Guo, M and Tan, S and Zhu, J and Sun, A and Du, P and Liu, X},
title = {Genes Involved in Biofilm Matrix Formation of the Food Spoiler Pseudomonas fluorescens PF07.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {881043},
doi = {10.3389/fmicb.2022.881043},
pmid = {35733961},
issn = {1664-302X},
abstract = {The extracellular matrix is essential for the biofilm formation of food spoilers. Pseudomonas fluorescens PF07 is a previous isolate from spoiled marine fish; however, the genes involved in the extracellular matrix formation of PF07 biofilms remain poorly defined. In this study, PF07 formed a wrinkled macrocolony biofilm through the high production of extracellular matrix. The genes involved in biofilm matrix formation and regulation were screened and identified by RNA-seq-dependent transcriptomic analysis and gene knock-out analysis. The macrocolony biofilms of PF07 grown for 5 days (PF07_5d) were compared with those grown for 1 day (PF07_1d). A total of 1,403 genes were significantly differentially expressed during biofilm formation. These mainly include the genes related to biofilm matrix proteins, polysaccharides, rhamnolipids, secretion system, biofilm regulation, and metabolism. Among them, functional amyloid genes fapABCDE were highly upregulated in the mature biofilm, and the operon fapA-E had a -24/-12 promoter dependent on the sigma factor RpoN. Moreover, the RNA-seq analyses of the rpoN mutant, compared with PF07, revealed 159 genes were differentially expressed in the macrocolony biofilms, and fapA-E genes were positively regulated by RpoN. In addition, the deletion mutants of fapC, rpoN, and brfA (a novel gene coding for an RpoN-dependent transcriptional regulator) were defective in forming mature macrocolony biofilms, solid surface-associated (SSA) biofilms, and pellicles, and they showed significantly reduced biofilm matrices. The fap genes were significantly downregulated in ΔbrfA, as in ΔrpoN. These findings suggest that the functional amyloid Fap is the main component of PF07 biofilm matrices, and RpoN may directly regulate the transcription of fap genes, in conjunction with BrfA. These genes may serve as potential molecular targets for screening new anti-biofilm agents or for biofilm detection in food environments.},
}
@article {pmid35731072,
year = {2022},
author = {Bai, P and Li, Y and Bai, J and Xu, H},
title = {Markedly decreased growth rate and biofilm formation ability of Acinetobacter schindleri after a long-duration (64 days) spaceflight.},
journal = {European review for medical and pharmacological sciences},
volume = {26},
number = {11},
pages = {4001-4015},
doi = {10.26355/eurrev_202206_28971},
pmid = {35731072},
issn = {2284-0729},
abstract = {OBJECTIVE: The objective of this study was to investigate the effects of long-duration space flight on the biological characteristics of Acinetobacter schindleri (A. schindleri).<br><br>MATERIALS AND METHODS: In this study, an A. schindleri strain was collected from condensate water of the Shenzhou-10 spacecraft and then was sent into space again to the Tiangong-2 space lab for a long-duration spaceflight (64 days). Later, the impacts of the long-duration spaceflight on phenotype, genome and transcriptome of A. schindleri were analyzed.<br><br>RESULTS: It was found that the long-duration spaceflight markedly decreased the growth rate and biofilm formation ability of A. schindleri. Furthermore, comparative genomic and transcriptomic analyses revealed that the decreased growth rate might be associated with differentially expressed genes (DEGs) involved in transmembrane transport, energy production and conversion, and biofilm was reduced due to downregulation of the pil and algR genes.<br><br>CONCLUSIONS: The findings are of major importance for predicting bacterial pathogenesis mechanisms and possible spacecraft contamination during long-duration spaceflights in the future.},
}
@article {pmid35730273,
year = {2022},
author = {Hughes, JM and Eberl, HJ and Sonner, S},
title = {A mathematical model of discrete attachment to a cellulolytic biofilm using random DEs.},
journal = {Mathematical biosciences and engineering : MBE},
volume = {19},
number = {7},
pages = {6582-6619},
doi = {10.3934/mbe.2022310},
pmid = {35730273},
issn = {1551-0018},
abstract = {We propose a new mathematical framework for the addition of stochastic attachment to biofilm models, via the use of random ordinary differential equations. We focus our approach on a spatially explicit model of cellulolytic biofilm growth and formation that comprises a PDE-ODE coupled system to describe the biomass and carbon respectively. The model equations are discretized in space using a standard finite volume method. We introduce discrete attachment events into the discretized model via an impulse function with a standard stochastic process as input. We solve our model with an implicit ODE solver. We provide basic simulations to investigate the qualitative features of our model. We then perform a grid refinement study to investigate the spatial convergence of our model. We investigate model behaviour while varying key attachment parameters. Lastly, we use our attachment model to provide evidence for a stable travelling wave solution to the original PDE-ODE coupled system.},
}
@article {pmid35729017,
year = {2022},
author = {Haji Hossein Tabrizi, A and Habibi, M and Foroohi, F and Mohammadian, T and Asadi Karam, MR},
title = {Investigation of the effects of antimicrobial and anti-biofilm peptide IDR1018 and chitosan nanoparticles on ciprofloxacin-resistant Escherichia coli.},
journal = {Journal of basic microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1002/jobm.202200156},
pmid = {35729017},
issn = {1521-4028},
abstract = {Peptide IDR1018 and chitosan nanoparticles (CNs) showed antimicrobial and anti-biofilm activity against bacteria. In this study, the antimicrobial effects of peptide IDR1018 and CNs were evaluated on 50 clinical isolates of uropathogenic Escherichia coli (UPEC) resistant to ciprofloxacin. Ion gelation method was applied for CNs synthesis. Scanning electron microscope (SEM) and dynamic light scattering (DLS) were utilized to evaluate the nanoparticles. Antimicrobial and synergistic activity of peptide IDR1018 and CNs with ciprofloxacin were evaluated by microtiter broth dilution method. The checkerboard test was used to investigate the antimicrobial effects of IDR1018 and CNS in combination with ciprofloxacin. Anti-biofilm effect of ciprofloxacin, peptide IDR1018, and CNs was evaluated using crystal violet method. Fourteen (28%), 21 (42%), and 15 (30%) of clinical isolates produced strong, moderate, and weak biofilm, respectively. The CNs were spherical and uniform under electron microscopy with an average diameter of 246 nm. The minimum inhibitory concentration (MIC) values were 16-128, 20-40, and 375-750 (µg/ml) for ciprofloxacin, peptide IDR1018, and CNs, respectively. Fractional inhibitory concentration (FIC) analysis indicated a synergistic effect of ciprofloxacin in combination with peptide IDR1018, but in combination with CNs, this antibiotic showed an additive effect. Our results revealed that peptide IDR1018 and CNs have antimicrobial properties on UPEC isolates. Biofilm inhibition and biofilm eradication of clinical isolate were shown by peptide IDR1018 and CNs in a concentration-dependent manner. The antimicrobial agents alone and in combination decreased the number of viable bacteria in the biofilms. Therefore, these components seem to be a treating approach against biofilm-forming UPEC isolates.},
}
@article {pmid35728770,
year = {2022},
author = {Abdulghani, M and Iram, R and Chidrawar, P and Bhosle, K and Kazi, R and Patil, R and Kharat, K and Zore, G},
title = {Proteomic profile of Candida albicans biofilm.},
journal = {Journal of proteomics},
volume = {},
number = {},
pages = {104661},
doi = {10.1016/j.jprot.2022.104661},
pmid = {35728770},
issn = {1876-7737},
abstract = {Candida albicans biofilms are characterized by structural and cellular heterogeneity that confers antifungal resistance and immune evasion. Despite this, biofilm formation remains poorly understood. In this study, we used proteomic analysis to understand biofilm formation in C. albicans related to morphophysiological and architectural features. LC-MS/MS analysis revealed that 64 proteins were significantly modulated, of which 31 were upregulated and 33 were downregulated. The results indicate that metabolism (25 proteins), gene expression (13 proteins), stress response (7 proteins), and cell wall (5 proteins) composition are modulated. The rate of oxidative phosphorylation (OxPhos) and biosynthesis of UDP-N-acetylglucosamine, vitamin B6, and thiamine increased, while the rate of methionine biosynthesis decreased. There was a significant modification of the cell wall architecture due to higher levels of Sun41, Pir1 and Csh1 and increased glycosylation of proteins. It was observed that C. albicans induces hyphal growth by upregulating the expression of genes involved in cAMP-PKA and MAPK pathways. This study is significant in that it suggests an increase in OxPhos and alteration of cell wall architecture that could be contributing to the recalcitrance of C. albicans cells growing in biofilms. Nevertheless, a deeper investigation is needed to explore it further. SIGNIFICANCE: Candida sps is included in the list of pathogens with potential drug resistance threat due to the increased frequency especially colonization of medical devices, and tissues among the patients, in recent years. Significance of our study is that we are reporting traits like modulation in cell wall composition, amino acid and vitamin biosynthesis and importantly energy generation (OxPhos) etc. These traits could be conferring antifungal resistance, host immune evasion etc. and thus survival, in addition to facilitating biofilm formation. These findings are expected to prime the further studies on devising potent strategy against biofilm growth among the patients.},
}
@article {pmid35728312,
year = {2022},
author = {Zheng, P and Li, Y and Chi, Q and Cheng, Y and Jiang, X and Chen, D and Mu, Y and Shen, J},
title = {Structural characteristics and microbial function of biofilm in membrane-aerated biofilm reactor for the biodegradation of volatile pyridine.},
journal = {Journal of hazardous materials},
volume = {437},
number = {},
pages = {129370},
doi = {10.1016/j.jhazmat.2022.129370},
pmid = {35728312},
issn = {1873-3336},
abstract = {In order to avoid the serious air pollution caused by the volatilization of high recalcitrant pyridine, membrane-aerated biofilm reactor (MABR) with bubble-free aeration was used in this study, with the structural characteristics and microbial function of biofilm emphasized. The results showed that as high as 0.6 kg·m-3·d-1 pyridine could be completely removed in MABR. High pyridine loading thickened the biofilm, but without obvious detachment observed. The distinct stratification of microbes and extracellular polymeric substances were shaped by elevated pyridine load, enhancing the structural heterogeneity of biofilm. The increased tryptophan-like substances as well as α-helix and β-sheet proportion in proteins stabilized the biofilm structure against high influent loading. Based on the identified intermediates, possible pyridine biodegradation pathways were proposed. Multi-omics analyses revealed that the metabolic pathways with initial hydroxylation and reduction reaction was enhanced at high pyridine loading. The functional genes were mainly associated with Pseudomonas and Delftia, might responsible for pyridine biodegradation. The results shed light on the effective treatment of wastewater containing recalcitrant pollutants such as pyridine via MABR.},
}
@article {pmid35727518,
year = {2022},
author = {Saygin, H and Baysal, A},
title = {Interaction of nanoplastics with simulated biological fluids and their effect on the biofilm formation.},
journal = {Environmental science and pollution research international},
volume = {},
number = {},
pages = {},
pmid = {35727518},
issn = {1614-7499},
support = {2021/03//Istanbul Aydin University/ ; },
abstract = {Over the last decade, it has become clear that the pollution by plastic debris presents global societal, environmental, and human health challenges. Moreover, humans are exposed to plastic particles in daily life and very limited information is available concerning human health, especially interactions with biological fluids. Therefore, the aim of this study is to investigate the interaction of plastic particles with simulated biological fluids (e.g., artificial saliva, artificial lysosomal fluid, phagolysosomal simulant fluid, and Gamble's solution) using various exposure stages (2 h to 80 h) and the effect of plastic particles on the formation of Staphylococcus aureus biofilms under simulated biological conditions. The plastic particles incubating various simulated biological fluids were characterized using surface functional groups, zeta potentials, and elemental composition. The results indicated that functional group indices (C-O, C = O, C-H, C = C, C-N, S = O, and OH) decreased compared to the control group during the incubation periods, except for the hydroxyl group index. The FTIR results showed that the hydroxyl group formed with the artificial lysosomal fluid, the phagolysosomal simulant fluid, and Gamble's solution. With the impact of the declining functional groups, the zeta potentials were more negative than in the control. Moreover, EDX results showed the release of the components in the particles with the interaction of simulated biological fluids as well as new components like P and Ca introduced to the particles. The biofilms were formed in the presence of nanoplastic particles under both controlled conditions and simulated biological conditions. The amount of biofilm formation was mainly affected by the surface characteristics under simulated biological conditions. In addition, the biofilm characteristics were influenced by the O/C and N/C ratios of the plastic particles with the impact of simulated biological fluids.},
}
@article {pmid35724713,
year = {2022},
author = {Xiong, H and Yang, G and Shan, X and Miao, L},
title = {Unveiling the effect of acetate on the interactions of functional bacteria in an anammox biofilm system.},
journal = {Chemosphere},
volume = {},
number = {},
pages = {135408},
doi = {10.1016/j.chemosphere.2022.135408},
pmid = {35724713},
issn = {1879-1298},
abstract = {Biodegradable organics make an important impact on anaerobic ammonium oxidation (anammox) system. In this study, acetate was selected as a typical biodegradable organic, and its effect on the anammox biofilm system was comprehensively discussed from the macro and micro perspectives. Under a low influent concentration of acetate (<240 ± 10 mg/L), the best total nitrogen (TN) removal performance was 96%, but it decreased to 83% when the acetate concentration increased to 350 ± 20 mg/L. With the addition of acetate, the relative abundance of the family Brocadiaceae, which contains all known anammox bacteria, gradually increased from 7.97% to 12.79%, indicating that the presence of acetate promoted enrichment of anammox bacteria in the biofilm. Metagenomic analysis further demonstrated that an appropriate concentration of acetate helps to increase the abundances of the key enzymes related to nitrogen removal and enhance the metabolism of anammox and denitrification, thereby promoting the synergy of anammox and denitrifying bacteria. Hydrazine synthase (hzs), which is unique to the anammox process, was detected in association with the genera Candidatus Kuenenia, Candidatus Jettenia and Candidatus Brocadia, with its abundance increasing from 13268 (with no addition of acetate) to 19186 (with acetate addition of 240 ± 10 mg/L). This work provides a deeper understanding of the intrinsic interactions between functional bacteria in an anammox biofilm system.},
}
@article {pmid35724257,
year = {2022},
author = {Said, M and Hom, DB},
title = {Commentary on "Evidence of Biofilm and Persister Cell Formation in Revision Rhinoplasty" by Kao et al.},
journal = {Facial plastic surgery &amp; aesthetic medicine},
volume = {24},
number = {3},
pages = {238-239},
doi = {10.1089/fpsam.2022.0118},
pmid = {35724257},
issn = {2689-3622},
mesh = {Anti-Bacterial Agents ; Biofilms ; Humans ; Reoperation ; *Rhinoplasty ; },
}
@article {pmid35724255,
year = {2022},
author = {Kao, WK and Faddis, B and Chole, RA and Davis, RE},
title = {Evidence of Biofilm and Persister Cell Formation in Revision Rhinoplasty.},
journal = {Facial plastic surgery &amp; aesthetic medicine},
volume = {24},
number = {3},
pages = {233-238},
doi = {10.1089/fpsam.2021.0378},
pmid = {35724255},
issn = {2689-3622},
mesh = {Biofilms ; Humans ; Nose/surgery ; *Nose Deformities, Acquired/surgery ; Postoperative Complications/surgery ; Reoperation ; *Rhinoplasty/methods ; },
abstract = {Background: Postoperative rhinoplasty infection can lead to serious cosmetic deformity, loss of structural integrity to the nose, and functional deficiencies. Understanding the factors contributing to postoperative infection is important. Microbial biofilms and persister cells play an important role in health care-associated infections. The objective of this study is to identify microbial biofilm and persister cells in the nasal soft tissue of patients undergoing revision rhinoplasty. Methods: Fourteen patients undergoing rhinoplasty were recruited for this study. Nasal soft tissue was removed during rhinoplasty and preserved in 2% paraformaldehyde/2.5% glutaraldehyde. High-resolution images were then obtained from these nasal soft tissue samples. Results: Three samples were positive for the presence of microbial persister cells or biofilms. All samples came from patients undergoing revision rhinoplasty. These patients had between one to six previous rhinoplasty procedures and one patient had previous injectable nasal filler. Conclusions: Biofilms and persister cells are able to form in nasal soft tissue of revision rhinoplasty patients in the absence of an implant and may contribute to increased postoperative infection risk.},
}
@article {pmid35723966,
year = {2022},
author = {Austin, PD and Stapleton, P and Elia, M},
title = {Comparative effect of seven prophylactic locks to prevent biofilm biomass and viability in intravenous catheters.},
journal = {The Journal of antimicrobial chemotherapy},
volume = {},
number = {},
pages = {},
doi = {10.1093/jac/dkac181},
pmid = {35723966},
issn = {1460-2091},
support = {//Health Education England/ ; //HEE/ ; //National Institute for Health Research/ ; //NIHR/ ; },
abstract = {BACKGROUND: Patients requiring long-term intravenous access are at risk of intraluminal catheter bloodstream infection. 'Prophylactic' locks aim to limit this risk but there is uncertainty regarding the most effective lock.<br><br>OBJECTIVES: To develop a novel technique intended to replicate clinical procedures to compare the effectiveness of various 'prophylactic' locks against biofilm biomass ('biomass') formation and biofilm viability ('viability') of Escherichia coli and Staphylococcus epidermidis in intravenous catheters.<br><br>METHODS: For 10 consecutive days 106 cfu/mL E. coli NCTC 10418 and S. epidermidis ATCC 12228 were separately cultured in single lumen 9.6 French silicone tunnelled and cuffed catheters. These were flushed with 0.9% w/v sodium chloride using a push-pause technique before and after instillation of seven 'prophylactic' locks (water, ethanol, sodium chloride, heparinized sodium chloride, citrate, taurolidine plus citrate, and taurolidine; each in triplicate) for 6 h daily. Intraluminal 'biomass' and 'viability' were quantified using crystal violet staining and flush culture, respectively.<br><br>RESULTS: The reduction of 'biomass' and 'viability' depended on both agent and species. Citrate was least effective against E. coli 'viability' and 'biomass' but most effective against S. epidermidis 'viability', and taurolidine was most effective against E. coli 'biomass' and 'viability' but least effective against S. epidermidis 'viability'. 'Biomass' and 'viability' were significantly correlated in E. coli between (r = 0.997, P < 0.001) and within (r = 0.754, P = 0.001) interventions, but not in S. epidermidis.<br><br>CONCLUSIONS: A novel technique found the effect of 'prophylactic' agents in reducing 'biomass' and 'viability' varied by species. The choice of agent depends on the most likely infecting organism.},
}
@article {pmid35722343,
year = {2022},
author = {Dong, K and Feng, X and Yao, Y and Zhu, Z and Lin, H and Zhang, X and Wang, D and Li, H},
title = {Nitrogen Removal From Nitrate-Containing Wastewaters in Hydrogen-Based Membrane Biofilm Reactors via Hydrogen Autotrophic Denitrification: Biofilm Structure, Microbial Community and Optimization Strategies.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {924084},
doi = {10.3389/fmicb.2022.924084},
pmid = {35722343},
issn = {1664-302X},
abstract = {The hydrogen-based membrane biofilm reactor (MBfR) has been widely applied in nitrate removal from wastewater, while the erratic fluctuation of treatment efficiency is in consequence of unstable operation parameters. In this study, hydrogen pressure, pH, and biofilm thickness were optimized as the key controlling parameters to operate MBfR. The results of 653.31 μm in biofilm thickness, 0.05 MPa in hydrogen pressure and pH in 7.78 suggesting high-efficiency NO 3 - - N removal and the NO 3 - - N removal flux was 1.15 g·m-2 d-1. 16S rRNA gene analysis revealed that Pseudomonas, Methyloversatilis, Thauera, Nitrospira, and Hydrogenophaga were the five most abundant bacterial genera in MBfRs after optimization. Moreover, significant increases of Pseudomonas relative abundances from 0.36 to 9.77% suggested that optimization could effectively remove nitrogen from MBfRs. Membrane pores and surfaces exhibited varying degrees of calcification during stable operation, as evinced by Ca2+ precipitation adhering to MBfR membrane surfaces based on scanning electron microscopy (SEM), atomic force microscopy (AFM) analyses. Scanning electron microscopy-energy dispersive spectrometer (SEM-EDS) analyses also confirmed that the primary elemental composition of polyvinyl chloride (PVC) membrane surfaces after response surface methodology (RSM) optimization comprised Ca, O, C, P, and Fe. Further, X-ray diffraction (XRD) analyses indicated the formation of Ca5F(PO4)3 geometry during the stable operation phase.},
}
@article {pmid35722322,
year = {2022},
author = {Pombo, JP and Ebenberger, SP and Müller, AM and Wolinski, H and Schild, S},
title = {Impact of Gene Repression on Biofilm Formation of Vibrio cholerae.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {912297},
doi = {10.3389/fmicb.2022.912297},
pmid = {35722322},
issn = {1664-302X},
abstract = {Vibrio cholerae, the etiological agent of cholera, is a facultative intestinal pathogen which can also survive in aquatic ecosystems in the form of biofilms, surface-associated microbial aggregates embedded in an extracellular matrix, which protects them from predators and hostile environmental factors. Biofilm-derived bacteria and biofilm aggregates are considered a likely source for cholera infections, underscoring the importance of V. cholerae biofilm research not just to better understand bacterial ecology, but also cholera pathogenesis in the human host. While several studies focused on factors induced during biofilm formation, genes repressed during this persistence stage have been fairly neglected. In order to complement these previous studies, we used a single cell-based transcriptional reporter system named TetR-controlled recombination-based in-biofilm expression technology (TRIBET) and identified 192 genes to be specifically repressed by V. cholerae during biofilm formation. Predicted functions of in-biofilm repressed (ibr) genes range from metabolism, regulation, surface association, transmembrane transport as well as motility and chemotaxis. Constitutive (over)-expression of these genes affected static and dynamic biofilm formation of V. cholerae at different stages. Notably, timed expression of one candidate in mature biofilms induced their rapid dispersal. Thus, genes repressed during biofilm formation are not only dispensable for this persistence stage, but their presence can interfere with ordered biofilm development. This work thus contributes new insights into gene silencing during biofilm formation of V. cholerae.},
}
@article {pmid35718788,
year = {2022},
author = {Gupta, KK and Sharma, KK and Chandra, H},
title = {Micrococcus luteus strain CGK112 isolated from cow dung demonstrated efficient biofilm-forming ability and degradation potential toward high-density polyethylene (HDPE).},
journal = {Archives of microbiology},
volume = {204},
number = {7},
pages = {402},
pmid = {35718788},
issn = {1432-072X},
mesh = {Animals ; Bacteria/metabolism ; Biodegradation, Environmental ; Biofilms ; Carbon/metabolism ; Cattle ; Female ; *Micrococcus luteus/genetics/metabolism ; *Polyethylene/metabolism ; RNA, Ribosomal, 16S/genetics/metabolism ; Spectroscopy, Fourier Transform Infrared ; },
abstract = {Biodegradation is the most promising environmentally sustainable method that offers a significant opportunity with minimal negative environmental consequences while searching for solutions to this global problem of plastic pollution that has now spread to almost everywhere in the entire world. In the present work, HDPE-degrading bacterial strain CGK112 was isolated from the fecal matter of a cow. The bacterial strain was identified as Micrococcus luteus CGK112 by 16S rRNA sequence coding analysis. Significant weight loss, i.e., 3.85% was recorded in the HDPE film treated with strain CGK112 for 90 days. The surface micromorphology was examined using FE-SEM, which revealed spectacular bacterial colonization as well as structural deformation. Furthermore, the EDX study indicated a significant decrease in the atomic percentage of carbon content, whereas FTIR analysis confirmed functional groups alternation as well as an increase in the carbonyl index which can be attributed to the metabolic activity of biofilm. Our findings provide insight into the capacity of our strain CGK112 to colonize and utilize HDPE as a single carbon source, thus promoting its degradation.},
}
@article {pmid35718173,
year = {2022},
author = {Alrashed, W and Chandra, R and Abbott, T and Lee, HS},
title = {Nitrite reduction using a membrane biofilm reactor (MBfR) in a hypoxic environment with dilute methane under low pressures.},
journal = {The Science of the total environment},
volume = {},
number = {},
pages = {156757},
doi = {10.1016/j.scitotenv.2022.156757},
pmid = {35718173},
issn = {1879-1026},
abstract = {Methane-based membrane biofilm reactors (MBfRs) can be an effective solution for nitrogen control in wastewater, but there is limited information on nitrite reduction for dilute wastewater (e.g., municipal wastewater) in hypoxic MBfRs. This study assessed the impacts of dilute (20 %), low-pressure methane (0.35-2.41 kPa) applied to MBfRs at hydraulic retention times (HRTs) of 2-12 h on nitrite removals, dissolved methane concentrations, and the resulting changes in the microbial community. High nitrite flux along with rapid and virtually complete (>99 %) nitrite removals were observed at methane pressures of 1.03-2.41 kPa at HRTs above 4 h, despite the use of diluted methane gas for the MBfR. The lowest methane pressure (0.35 kPa) was also able to achieve up to 98 % nitrite removals but required HRTs of up to 12 h. All scenarios had low dissolved methane concentrations (<10 mg/L), indicating that dilute methane at low supply pressures can effectively remove nitrite while meeting dissolved methane guidelines in treated effluent. Methylococcus genus was the key bacterium in MBfR biofilm grown at different HRTs and methane pressures, along with Methylocystis and other heterotrophic denitrifiers (Terrimonas and Hyphomicrobium). This study indicates that methane-based denitrification MBfRs can be a valuable tool to meet nitrogen limits for dilute wastewater coupled to partial nitrification, while limiting the release of methane to the environment.},
}
@article {pmid35718162,
year = {2022},
author = {Jia, J and Xue, X and Guan, Y and Fan, X and Wang, Z},
title = {Biofilm characteristics and transcriptomic profiling of Acinetobacter johnsonii defines signatures for planktonic and biofilm cells.},
journal = {Environmental research},
volume = {213},
number = {},
pages = {113714},
doi = {10.1016/j.envres.2022.113714},
pmid = {35718162},
issn = {1096-0953},
abstract = {Most bacteria in the natural environment have a biofilm mode of life, which is intrinsically tolerant to antibiotics. While until now, the knowledge of biofilm formation by Acinetobacter johnsonii is not well understood. In this study, the characteristics and the effect of a sub-inhibitory concentration of antibiotic on A. johnsonii biofilm and planktonic cells were determined. We discovered a positive relationship between biofilm formation and tetracycline resistance, and biofilms rapidly evolve resistance to tetracycline they are treated with. Persister cells commonly exist in both planktonic and biofilm cells, with a higher frequency in the latter. Further transcriptomic analysis speculates that the overexpression of multidrug resistance genes and stress genes were mainly answered to sub lethal concentration of tetracycline in planktonic cells, and the lower metabolic levels after biofilm formation result in high resistance level of biofilm cells to tetracycline. Altogether, these data suggest that A. johnsonii can adjust its phenotype when grown as biofilm and change its metabolism under antibiotic stress, and provide implications for subsequent biofilm control.},
}
@article {pmid35717506,
year = {2022},
author = {Crescente, CL and de Sousa, ET and Lima-Holanda, AT and Steiner-Oliveira, C and Nobre-Dos-Santos, M},
title = {Biofilm accumulation and sucrose rinse modulate calcium and fluoride bioavailability in the saliva of children with early childhood caries.},
journal = {Scientific reports},
volume = {12},
number = {1},
pages = {10283},
pmid = {35717506},
issn = {2045-2322},
support = {2017/17630-8//Fundação de Amparo à Pesquisa do Estado de São Paulo/ ; 45631-18//Fundação de Desenvolvimento da Unicamp/ ; },
mesh = {Biofilms ; Biological Availability ; Calcium/pharmacology ; Calcium, Dietary/pharmacology ; Child ; Child, Preschool ; *Dental Caries ; Dental Caries Susceptibility ; Female ; *Fluorides/pharmacology ; Humans ; Male ; Phosphates/pharmacology ; Saliva ; Sucrose/pharmacology ; },
abstract = {This study aimed at investigating the combined effect of biofilm accumulation and 20% sucrose rinse on the modulation of calcium (Ca2+), phosphate (Pi), and fluoride (F-) bioavailability in the saliva of children with early childhood caries (ECC). Fifty-six preschoolers of both genders were evaluated according to caries experience and activity: caries-free (CF, n = 28) and with ECC (n = 28) and then, submitted to biofilm intervention (biofilm accumulation). In each situation, saliva samples were collected before and five minutes after a 20% sucrose rinse to determine the concentrations of Ca2+, Pi, and F-. Calcium concentration was significantly lower in the biofilm accumulation situation compared to the situation of biofilm mechanical control (p ≤ 0.01), except for CF children after sucrose rinse. Biofilm accumulation increased salivary calcium concentration in children with ECC after sucrose rinse (p = 0.04), whereas mechanical biofilm control reduced it in both groups (p = 0.000). Phosphate concentration was influenced by mechanical control of biofilm in CF children (p = 0.03). The fluoride bioavailability was reduced by sucrose rinse and biofilm accumulation in CF and ECC children (p ≤ 0.002). In conclusion, the combined effect of biofilm accumulation and sucrose rinse modifies the bioavailability of calcium and fluoride in the saliva of children with early childhood caries.},
}
@article {pmid35717090,
year = {2022},
author = {Pan, L and Wan, Z and Feng, Q and Wang, J and Xiong, J and Wang, S and Zhu, H and Chen, G},
title = {Biofilm response and removal via the coupling of visible-light-driven photocatalysis and biodegradation in an environment of sulfamethoxazole and Cr(VI).},
journal = {Journal of environmental sciences (China)},
volume = {122},
number = {},
pages = {50-61},
doi = {10.1016/j.jes.2021.09.038},
pmid = {35717090},
issn = {1001-0742},
mesh = {Biofilms ; Catalysis ; Chromium ; *Environmental Pollutants ; *Sulfamethoxazole ; Titanium ; },
abstract = {The widespread contamination of water systems with antibiotics and heavy metals has gained much attention. Intimately coupled visible -light-responsive photocatalysis and biodegradation (ICPB) provides a novel approach for removing such mixed pollutants. In ICPB, the photocatalysis products are biodegraded by a protected biofilm, leading to the mineralization of refractory organics. In the present study, the ICPB approach exhibited excellent photocatalytic activity and biodegradation, providing up to ∼1.27 times the degradation rate of sulfamethoxazole (SMX) and 1.16 times the Cr(VI) reduction rate of visible-light-induced photocatalysis . Three-dimensional fluorescence analysis demonstrated the synergistic ICPB effects of photocatalysis and biodegradation for removing SMX and reducing Cr(VI). In addition, the toxicity of the SMX intermediates and Cr(VI) in the ICPB process significantly decreased. The use of MoS2/CoS2 photocatalyst accelerated the separation of electrons and holes, with•O2- and h+ attacking SMX and e- reducing Cr(VI), providing an effective means for enhancing the removal and mineralization of these mixed pollutants via the ICPB technique. The microbial community results demonstrate that bacteria that are conducive to pollutant removal are were enriched by the acclimation and ICPB operation processes, thus significantly improving the performance of the ICPB system.},
}
@article {pmid35717079,
year = {2022},
author = {Arabgol, R and Vanrolleghem, PA and Delatolla, R},
title = {Influence of MBBR carrier geometrical properties and biofilm thickness restraint on biofilm properties, effluent particle size distribution, settling velocity distribution, and settling behaviour.},
journal = {Journal of environmental sciences (China)},
volume = {122},
number = {},
pages = {138-149},
doi = {10.1016/j.jes.2021.09.029},
pmid = {35717079},
issn = {1001-0742},
mesh = {*Biofilms ; *Bioreactors ; Particle Size ; Waste Disposal, Fluid/methods ; },
abstract = {The relatively poor settling characteristics of particles produced in moving bed biofilm reactor (MBBR) outline the importance of developing a fundamental understanding of the characterization and settleability of MBBR-produced solids. The influence of carrier geometric properties and different levels of biofilm thickness on biofilm characteristics, solids production, particle size distribution (PSD), and particle settling velocity distribution (PSVD) is evaluated in this study. The analytical ViCAs method is applied to the MBBR effluent to assess the distribution of particle settling velocities. This method is combined with microscopy imaging to relate particle size distribution to settling velocity. Three conventionally loaded MBBR systems are studied at a similar loading rate of 6.0 g/(m2 •day) and with different carrier types. The AnoxK™ K5 carrier, a commonly used carrier, is compared to so-called thickness-restraint carriers, AnoxK™ Z-carriers that are newly designed carriers to limit the biofilm thickness. Moreover, two levels of biofilm thickness, 200 μm and 400 μm, are studied using AnoxK™ Z-200 and Z-400 carriers. Statistical analysis confirms that K5 carriers demonstrated a significantly different biofilm mass, thickness, and density, in addition to distinct trends in PSD and PSVD in comparison with Z-carriers. However, in comparison of thickness-restraint carriers, Z-200 carrier results did not vary significantly compared to the Z-400 carrier. The K5 carriers showed the lowest production of suspended solids (0.7 ± 0.3 g-TSS/day), thickest biofilm (281.1 ± 8.7 µm) and lowest biofilm density (65.0 ± 1.5 kg/m3). The K5 effluent solids also showed enhanced settling behaviour, consisting of larger particles with faster settling velocities.},
}
@article {pmid35716164,
year = {2022},
author = {Petrovic, M and Bonvin, D and Todic, J and Zivkovic, R and Randjelovic, M and Arsic Arsenijevic, V and Mionic Ebersold, M and Otasevic, S},
title = {Surface modification of Poly (methyl-methacrylate) with farnesol to prevent Candida biofilm formation.},
journal = {Letters in applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/lam.13772},
pmid = {35716164},
issn = {1472-765X},
abstract = {Candida albicans promote biofilm formation on dentures, which compromises the use of poly(methyl-methacrylate) (PMMA) as dental material. Farnesol (FAR), a natural compound that prevents C. albicans filamentation and biofilm formation, was incorporated into the PMMA matrix, to obtain antifungal PMMA_FAR materials. The tested concentrations (0.0125% and 0.4%) of FAR, 24h after incubation on YPD agar, inhibited filamentation of C. albicans. PMMA was modified with different FAR concentrations (3% - 12%), and physicochemical properties, antifungal activity, and cytotoxicity of these modified materials (PMMA_FAR) were tested. The presence of FAR in PMMA_FAR composites was verified by Fourier-transform infrared spectroscopy (FTIR). Incorporation of FAR into the polymeric matrix significantly decreased hydrophilicity at all tested concentrations and significantly reduced biofilm and planktonic cells metabolic activity in the early stage of biofilm formation at ≥ 6% FAR in PMMA. PMMA_FAR composites with < 9% FAR were non-toxic. Modification of PMMA with FAR is a good strategy for reducing C. albicans biofilm formation on dentures.},
}
@article {pmid35714383,
year = {2022},
author = {Benedek, T and Pápai, M and Gharieb, K and Bedics, A and Táncsics, A and Tóth, E and Daood, H and Maróti, G and Wirth, R and Menashe, O and Bóka, K and Kriszt, B},
title = {Nocardioides carbamazepini sp. nov., an ibuprofen degrader isolated from a biofilm bacterial community enriched on carbamazepine.},
journal = {Systematic and applied microbiology},
volume = {45},
number = {4},
pages = {126339},
doi = {10.1016/j.syapm.2022.126339},
pmid = {35714383},
issn = {1618-0984},
abstract = {From the metagenome of a carbamazepine amended selective enrichment culture the genome of a new to science bacterial species affiliating with the genus Nocardioides was reconstructed. From the same enrichment an aerobic actinobacterium, strain CBZ_1T, sharing 99.4% whole-genome sequence similarity with the reconstructed Nocardioides sp. bin genome was isolated. On the basis of 16S rRNA gene sequence similarity the novel isolate affiliated to the genus Nocardioides, with the closest relatives Nocardioides kongjuensis DSM19082T (98.4%), Nocardioides daeguensis JCM17460T (98.4%) and Nocardioides nitrophenolicus DSM15529T (98.2%). Using a polyphasic approach it was confirmed that the isolate CBZ_1T represents a new phyletic lineage within the genus Nocardioides. According to metagenomic, metatranscriptomic studies and metabolic analyses strain CZB_1T was abundant in both carbamazepine and ibuprofen enrichments, and harbors biodegradative genes involved in the biodegradation of pharmaceutical compounds. Biodegradation studies supported that the new species was capable of ibuprofen biodegradation. After 7 weeks of incubation, in mineral salts solution supplemented with glucose (3 g l-1) as co-substrate, 70% of ibuprofen was eliminated by strain CBZ_1T at an initial conc. of 1.5 mg l-1. The phylogenetic, phenotypic and chemotaxonomic data supported the classification of strain CBZ_1T to the genus Nocardioides, for which the name Nocardioides carbamazepini sp. nov. (CBZ_1T = NCAIM B.0.2663 = LMG 32395) is proposed. To the best of our knowledge, this is the first study that reports simultaneous genome reconstruction of a new to science bacterial species using metagenome binning and at the same time the isolation of the same novel bacterial species.},
}
@article {pmid35713471,
year = {2022},
author = {Liu, M and Huang, L and Xu, X and Wei, X and Yang, X and Li, X and Wang, B and Xu, Y and Li, L and Yang, Z},
title = {Copper Doped Carbon Dots for Addressing Bacterial Biofilm Formation, Wound Infection, and Tooth Staining.},
journal = {ACS nano},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsnano.2c02518},
pmid = {35713471},
issn = {1936-086X},
abstract = {Oral infectious diseases and tooth staining, the main challenges of dental healthcare, are inextricably linked to microbial colonization and the formation of pathogenic biofilms. However, dentistry has so far still lacked simple, safe, and universal prophylactic options and therapy. Here, we report copper-doped carbon dots (Cu-CDs) that display enhanced catalytic (catalase-like, peroxidase-like) activity in the oral environment for inhibiting initial bacteria (Streptococcus mutans) adhesion and for subsequent biofilm eradication without impacting the surrounding oral tissues via oxygen (O2) and reactive oxygen species (ROS) generation. Especially, Cu-CDs exhibit strong affinity for lipopolysaccharides (LPS) and peptidoglycans (PGN), thus conferring them with excellent antibacterial ability against Gram-positive bacteria (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli), such that they can prevent wound purulent infection and promoting rapid wound healing. Additionally, the Cu-CDs/H2O2 system shows a better performance in tooth whitening, compared with results obtained with other alternatives, e.g., CDs and clinically used H2O2, particularly its negligible enamel and dentin destruction. It is anticipated that the biocompatible Cu-CDs presented in this work are a promising nano-mouthwash for eliminating oral pathogenic biofilms, prompting wound healing as well as tooth whitening, highlighting their significance in oral health management.},
}
@article {pmid35711752,
year = {2022},
author = {Fei, P and Jing, H and Ma, Y and Dong, G and Chang, Y and Meng, Z and Jiang, S and Xie, Q and Li, S and Chen, X and Yang, W},
title = {Cronobacter spp. in Commercial Powdered Infant Formula Collected From Nine Provinces in China: Prevalence, Genotype, Biofilm Formation, and Antibiotic Susceptibility.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {900690},
doi = {10.3389/fmicb.2022.900690},
pmid = {35711752},
issn = {1664-302X},
abstract = {The purpose of this study was to investigate the prevalence of Cronobacter spp. in commercial powdered infant formula (PIF) from nine provinces in China from March 2018 to September 2020, and to reveal the genotype, biofilm-forming ability, and antibiotic susceptibility of these isolates. A total of 27 Cronobacter strains, consisting of 22 Cronobacter sakazakii strains, 3 Cronobacter malonaticus strains, 1 Cronobacter turicensis strain, and 1 Cronobacter dublinensis strain, were isolated from 3,600 commercial PIF samples with a prevalence rate of 0.75%. Compared with the other 8 provinces, PIF from Shaanxi province had a higher prevalence rate (1.25%) of Cronobacter spp. These isolates were divided into 14 sequence types (STs), and 6 Cronobacter serotypes. The main Cronobacter STs were ST4, ST1, and ST64, and the dominant Cronobacter serotype was C. sakazakii serotype O2. Approximately 88.89% of Cronobacter isolates had a strong ability (OD595 > 1) to form biofilms on tinplate, among which the strains with ST4 were more dominant. All isolates were susceptible to ampicillin-sulbactam, ceftriaxone, cefotaxime, sulfadiazine, sulfadoxine, trimethoprim-sulfamethoxazole, gentamicin, tetracycline, ciprofloxacin, and colistin, while 55.56 and 96.30% isolates were resistant to cephalothin and vancomycin, respectively. Taken together, our findings highlighted the contamination status and characterization of Cronobacter spp. in commercial PIF from nine provinces of China, and provided guidance for the effective prevention and control of this pathogen in the production of PIF.},
}
@article {pmid35709937,
year = {2022},
author = {Aleksić, A and Stojanović-Radić, Z and Harmanus, C and Kuijper, E and Stojanović, P},
title = {In vitro anti-clostridial action and potential of the spice herbs essential oils to prevent biofilm formation of hypervirulent Clostridioides difficile strains isolated from hospitalized patients with CDI.},
journal = {Anaerobe},
volume = {},
number = {},
pages = {102604},
doi = {10.1016/j.anaerobe.2022.102604},
pmid = {35709937},
issn = {1095-8274},
abstract = {BACKGROUND: Clostridioides difficile is the most common causative agent of antibiotic-acquired diarrhea in hospitalized patients associated with substantial morbidity and mortality. The global epidemic of CDI (Clostridioides difficile infection) began in the early 20th century with the emergence of the hypervirulent and resistant ribotype 027 strains, and requires an urgent search for new therapeutic agents.<br><br>OBJECTIVE: The aim of this study is to investigate the antibacterial activity of the three essential oils isolated from spice herbs (wild oregano, garlic and black pepper) against C. difficile clinical isolates belonging to 6 different PCR ribotypes and their potential inhibitory effect on the biofilm production in in vitro conditions.<br><br>RESULTS: Wild oregano essential oil showed strong inhibitory activity in concentrations 0.02-1.25 mg/mL and bactericidal activity in concentrations from 0.08 to 10 mg/mL. Garlic essential oil was effective in the concentration range of 0.02-40 mg/mL, and 0.16 - > 40 mg/mL. MIC and MBC for black pepper oil ranged from 0.04 to 40 mg/mL, and 0.08 - > 40 mg/mL, respectively. All the tested oils reduced in vitro biofilm production, with the best activity of oregano oil.<br><br>CONCLUSION: Essential oils of wild oregano, black pepper and garlic are candidates for adjunctive therapeutics in the treatment of CDI. Oregano oil should certainly be preferred due to the lack of selectivity of action in relation to the ribotype, the strength of the produced biofilm and/or antibiotic-susceptibility patterns.},
}
@article {pmid35709929,
year = {2022},
author = {Rajivgandhi, G and Ramachandran, G and Chackaravarthi, G and Chelliah, CK and Maruthupandy, M and Quero, F and Al-Mekhlafi, FA and Wadaan, MA and Jun-Li, W},
title = {Preparation of antibacterial Zn and Ni substituted cobalt ferrite nanoparticles for efficient biofilm eradication.},
journal = {Analytical biochemistry},
volume = {},
number = {},
pages = {114787},
doi = {10.1016/j.ab.2022.114787},
pmid = {35709929},
issn = {1096-0309},
abstract = {Zinc (Zn) and, alternatively, nickel (Ni) substituted cobalt ferrite (CF) nanoparticles (NPs) were prepared by sol-gel method. X-ray diffraction analysis revealed the formation of cubic structure of cobalt ferrite. FTIR analysis confirmed the vibrational band located at 550-580 cm-1 that belongs to the M-O bond (M = Ni, and Zn). The alteration of the surface morphology of CF after the addition of Zn and Ni ions was observed from scanning electron microscopic images. The additional peaks in the energy dispersive X-ray diffraction (EDX) analysis spectra were found to correspond to Zn and Ni. The presence of Zn and, alternatively, Ni ions enhanced the biocidal properties of CF NPs against gram negative organisms, in a concentration and time-dependent manner. Furthermore, exposure to CF, CF-Zn and CF-Ni NPs decreased metabolic activity due to the damage of extra polymorphic substances, live/dead cell variation, architecture and surface integrity of the cells. Altogether, the present investigation provides the basis of metal ion substituted metal oxide NPs as anti-biofilm agents against gram-positive and gram-negative bacteria.},
}
@article {pmid35709560,
year = {2022},
author = {de Siqueira, VM and da Silva, BGM and Passos, JCDS and Pinto, AP and da Rocha, JBT and Alberto-Silva, C and Costa, MS},
title = {(MeOPhSe)2, a synthetic organic selenium compound, inhibits virulence factors of Candida krusei: Adherence to cervical epithelial cells and biofilm formation.},
journal = {Journal of trace elements in medicine and biology : organ of the Society for Minerals and Trace Elements (GMS)},
volume = {73},
number = {},
pages = {127019},
doi = {10.1016/j.jtemb.2022.127019},
pmid = {35709560},
issn = {1878-3252},
abstract = {BACKGROUND: Systemic candidiasis is produced by Candida albicans or non-albicans Candida species, opportunistic fungi that produce both superficial and invasive infections. Despite the availability of a wide range of antifungal agents for the treatment of candidiasis, failure of therapy is observed frequently, which opens new avenues in the field of alternative therapeutic strategies.<br><br>METHODS: The effects of p,p'-methoxyl-diphenyl diselenide [(MeOPhSe)2], a synthetic organic selenium (organochalcogen) compound, were investigated on virulence factors of C. krusei and compared with its antifungal effects on the virulence factors related to adhesion to cervical epithelial cell surfaces with C. albicans.<br><br>RESULTS: (MeOPhSe)2, a compound non-toxic in epithelial (HeLa) and fibroblastic (Vero) cells, inhibited the growth in a dose-dependent manner and changed the kinetics parameters of C. krusei and, most importantly, extending the duration of lag phase of growth, inhibiting biofilm formation, and changing the structure of biofilm. Also, (MeOPhSe)2 reduced C. albicans and C. krusei adherence to cervical epithelial cells, an important factor for the early stage of the Candida-host interaction. The reduction was 37.24 ± 2.7 % in C. krusei (p = 0.00153) and 32.84 ± 3.2 % in C. albicans (p = 0.0072) at 20 µM (MeOPhSe)2, and the effect is in a concentration-dependent manner. Surprisingly, the antifungal potential on adhesion was similar between both species, indicating the potential of (MeOPhSe)2 as a promising antifungal drug against different Candida infections.<br><br>CONCLUSION: Overall, we demonstrated the potential of (MeOPhSe)2 as an effective antifungal drug against the virulence factors of Candida species.},
}
@article {pmid35708833,
year = {2022},
author = {Deepika, G and Subbarayadu, S and Chaudhary, A and Sarma, PVGK},
title = {Dibenzyl (benzo [d] thiazol-2-yl (hydroxy) methyl) phosphonate (DBTMP) showing anti-S. aureus and anti-biofilm properties by elevating activities of serine protease (SspA) and cysteine protease staphopain B (SspB).},
journal = {Archives of microbiology},
volume = {204},
number = {7},
pages = {397},
pmid = {35708833},
issn = {1432-072X},
mesh = {Biofilms ; Cysteine ; *Cysteine Proteases/genetics/metabolism ; *Organophosphonates/pharmacology ; Serine Endopeptidases/genetics/metabolism ; Serine Proteases/genetics ; Staphylococcus aureus/genetics/metabolism ; },
abstract = {Staphylococcus aureus biofilms are the pathogenic factor in the spread of infection and are more pronounced in multidrug-resistant strains of S. aureus, where high expression of proteases is observed. Among various proteases, Serine protease (SspA) and cysteine protease Staphopain B (SspB) are known to play a key role in the biofilm formation and removal of biofilms. In earlier studies, we have reported Dibenzyl (benzo [d] thiazol-2-yl (hydroxy) methyl) phosphonate (DBTMP) exhibits anti-S. aureus and anti-biofilm properties by elevating the expression of the protease. In this study, the effect of DBTMP on the activities of SspA, and SspB of S. aureus was evaluated. The SspA and SspB genes of S. aureus ATCC12600 were sequenced (Genbank accession numbers: MZ456982 and MW574006). In S. aureus active SspA is formed by proteolytic cleavage of immature SspA, to get this mature SspA (mSspA), we have PCR amplified the mSspA sequence from the SspA gene. The mSspA and SspB genes were cloned, expressed, and characterized. The pure recombinant proteins rSspB and rmSspA exhibited a single band in SDS-PAGE with a molecular weight of 40 and 30 KD, respectively. The activities of rmSspA and rSspB are 32.33 and 35.45 Units/mL correspondingly. DBTMP elevated the activities of rmSspA and rSspB by docking with respective enzymes. This compound disrupted the biofilms formed by the multidrug-resistant strains of S. aureus and further prevented biofilm formation. These findings explain that DBTMP possesses anti-S. aureus and anti-biofilm features.},
}
@article {pmid35707890,
year = {2022},
author = {Lim, H and Chung, JH and Park, Y and Baek, N and Seo, Y and Park, H and Cho, YK and Jung, D and Han, DH},
title = {Inner surface modification of ureteral stent polyurethane tubes based by plasma-enhanced chemical vapor deposition to reduce encrustation and biofilm formation.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-11},
doi = {10.1080/08927014.2022.2087513},
pmid = {35707890},
issn = {1029-2454},
abstract = {Encrustation and/or biofilm formation in ureteral stents are major causes of obstruction and reduce the lifetime of a ureteral stent. In this study, the inner surfaces of polyurethane (PU) tubes (inner and outer diameters of 1.2 and 2.0 mm, respectively) were reformed with Ar, O2, and C2H2 gases using specialized plasma-enhanced chemical vapor deposition techniques for the first time. Then, the modified PU tubes were immersed in urine for 15 days, and the characteristics of the inner surfaces were analyzed. Depending on the modification procedure, the corresponding inner surface exhibited different chemical properties and different rates of encrustation and biofilm formation. For a hydrophilic surface treated with Ar and O2, encrustation and biofilm formation increased, while for the C2H2 coating, the development of encrustation and biofilm reduced by more than five times compared with the untreated bare PU tube. This study demonstrated that inner plasma surface modification of ureteral stents greatly enhances resistance to encrustation and biofilm formation.},
}
@article {pmid35707153,
year = {2022},
author = {Consoli, GML and Granata, G and Ginestra, G and Marino, A and Toscano, G and Nostro, A},
title = {Antibacterial Nanoassembled Calix[4]arene Exposing Choline Units Inhibits Biofilm and Motility of Gram Negative Bacteria.},
journal = {ACS medicinal chemistry letters},
volume = {13},
number = {6},
pages = {916-922},
doi = {10.1021/acsmedchemlett.2c00015},
pmid = {35707153},
issn = {1948-5875},
abstract = {The high incidence of antibiotic resistance and biofilm-associated infections is still a major cause of morbidity and mortality and triggers the need for new antimicrobial drugs and strategies. Nanotechnology is an emerging approach in the search for novel antimicrobial agents. The aim of this study was to investigate the inherent antibacterial effects of a self-assembling amphiphilic choline-calix[4]arene derivative (Chol-Calix) against Gram negative bacteria. Chol-Calix showed activity against Escherichia coli and Pseudomonas aeruginosa, including antibiotic-resistant strains, and affected the bacterial biofilm and motility. The activity is likely related to the amphipathicity and cationic surface of Chol-Calix nanoassembly that can establish large contact interactions with the bacterial surface. Chol-Calix appears to be a promising candidate in the search for novel nanosized nonconventional antimicrobials.},
}
@article {pmid35704984,
year = {2022},
author = {Nosrati, M and Ranjbar, R},
title = {Investigation of the antibacterial and biofilm inhibitory activities of Prangos acaulis (DC.) Bornm in nanoparticulated formulation.},
journal = {Nanotechnology},
volume = {},
number = {},
pages = {},
doi = {10.1088/1361-6528/ac78f1},
pmid = {35704984},
issn = {1361-6528},
abstract = {Here in, a chitosan based nanoformulation of P.acaulis was evaluated for its antibacterial and antibiofilm inhibitory activities against some known foodborne bacteria. The FTIR, FE-SEM, DLS and zeta-potential analysis were performed for confirming loading process, morphological appearance, hydrodynamic diameter and surface charge of the nanoparticles respectively. The results confirmed that, the nanoparticles had semi-spherical shape with the mean hydrodynamic diameter and surface charge of 89.8±5.8 nm and 10.78±2.7 mv respectively. Furthermore, the FTIR analysis approved that the nanoparticles were successfully loaded with ethyl acetate fraction from P.acaulis. The antibacterial and biofilm inhibitory activities of the nanoformulated fraction were significantly increased against the tested Gram positive strains than free sample. The results also confirmed that the fraction release from the nanoparticles follows a sustained manner release after 30 h in a logarithmic pattern. Based on the obtained results, chitosan based nanoformulation of P. acaulis can be considered for more evaluations to serve as an alternative natural antibiotic.},
}
@article {pmid35704732,
year = {2022},
author = {Yarkarami, F and Kazemian, H and Sadeghifard, N and Pakzad, R and Jalilian, FA and Asadollahi, P and Hematian, A and Pakzad, I},
title = {Inhibitory Effects of Carvacrol on Biofilm Formation and Expression of Biofilm Related Genes in Clinical Isolates of Enterococcus faecalis.},
journal = {Clinical laboratory},
volume = {68},
number = {6},
pages = {},
doi = {10.7754/Clin.Lab.2021.210853},
pmid = {35704732},
issn = {1433-6510},
abstract = {BACKGROUND: Nowadays, novel antimicrobial strategies are being developed which focus on debilitating, rather than killing the microorganisms. In this regard, anti-biofilm therapy is one of the important ways to combat bacterial infections. Therefore, the aim of the current study was to evaluate the anti-biofilm activity of Carvacrol against E. faecalis by means of its effects on biofilm formation as well as on the gene expression levels of the two biofilm related genes, Epa and Esp.<br><br>METHODS: A total of 40 clinical strains of E. faecalis were collected from three hospitals in Tehran, Iran during 2020. These isolates were confirmed by biochemical and genotypic methods. Antibacterial and anti-biofilm activity of Carvacrol essence were determined according the standard protocol. Finally, expression level of the biofilm related genes (Epa and Esp) were evaluated before and after the treatment with Carvacrol.<br><br>RESULTS: A total of 14 isolates were considered as strong biofilm producers and were used for analysis. Carvacrol essence showed the best antibacterial activity at 2,500 μg/mL concentration against all the isolates, the biofilm formation capacity was decreased by Carvacrol essence, and it was statistically significant (p < 0.05). Expression levels of the Esp gene were decreased in 5 isolates while increased in 3 isolates following the Carvacrol treatment. Ex-pression levels of the EpaI gene was significantly decreased (p < 0.05) in 4 isolates following the Carvacrol treatment.<br><br>CONCLUSIONS: In conclusion, the results presented in this study suggest that carvacrol extract exhibits significant antimicrobial and anti-biofilm properties against E. faecalis, even against vancomycin resistant isolates.},
}
@article {pmid35704683,
year = {2022},
author = {Feitosa-Junior, OR and Souza, APS and Zaini, PA and Baccari, C and Ionescu, M and Pierry, PM and Uceda-Campos, G and Labroussaa, F and Almeida, RPP and Lindow, S and da Silva, AM},
title = {The XadA trimeric autotransporter adhesins in Xylella fastidiosa differentially contribute to cell aggregation, biofilm formation, insect transmission and virulence to plants.},
journal = {Molecular plant-microbe interactions : MPMI},
volume = {},
number = {},
pages = {},
doi = {10.1094/MPMI-05-22-0108-R},
pmid = {35704683},
issn = {0894-0282},
abstract = {Surface adhesion strategies are widely employed by bacterial pathogens during establishment and systemic spread in their host. A variety of cell surface appendages such as pili, fimbriae and afimbrial adhesins are involved in these processes. The phytopathogen Xylella fastidiosa employs several of these structures for efficient colonization of its insect and plant hosts. Among the adhesins encoded in the X. fastidiosa genome, three afimbrial adhesins, XadA1, Hsf/XadA2, and XadA3, are predicted to be trimeric autotransporters with a C-terminal YadA-anchor membrane domain. We analyzed the individual contributions of XadA1, XadA2, and XadA3 to various cellular behaviors both in vitro and in vivo. Using isogenic X. fastidiosa mutants, we found that cell-cell aggregation and biofilm formation were severely impaired in the absence of XadA3. No significant reduction of cell-surface attachment was found with any mutant under flow conditions. Acquisition by insect vectors and transmission to grapevines were reduced in the XadA3 deletion mutant. While the XadA3 mutant was hypervirulent in grapevines, XadA1 or XadA2 deletion mutants conferred lower disease severity than the wild-type strain. This insight of the importance of these adhesive proteins and their individual contributions to different aspects of X. fastidiosa biology should guide new approaches to reduce pathogen transmission and disease development.},
}
@article {pmid35704575,
year = {2022},
author = {Worlitzer, VM and Jose, A and Grinberg, I and Bär, M and Heidenreich, S and Eldar, A and Ariel, G and Be'er, A},
title = {Biophysical aspects underlying the swarm to biofilm transition.},
journal = {Science advances},
volume = {8},
number = {24},
pages = {eabn8152},
doi = {10.1126/sciadv.abn8152},
pmid = {35704575},
issn = {2375-2548},
abstract = {Bacteria organize in a variety of collective states, from swarming-rapid surface exploration, to biofilms-highly dense immobile communities attributed to stress resistance. It has been suggested that biofilm and swarming are oppositely controlled, making this transition particularly interesting for understanding the ability of bacterial colonies to adapt to challenging environments. Here, the swarm to biofilm transition is studied in Bacillus subtilis by analyzing the bacterial dynamics both on the individual and collective scales. We show that both biological and physical processes facilitate the transition. A few individual cells that initiate the biofilm program cause nucleation of large, approximately scale-free, stationary aggregates of trapped swarm cells. Around aggregates, cells continue swarming almost unobstructed, while inside, trapped cells are added to the biofilm. While our experimental findings rule out previously suggested purely physical effects as a trigger for biofilm formation, they show how physical processes, such as clustering and jamming, accelerate biofilm formation.},
}
@article {pmid35703501,
year = {2022},
author = {Wu, C and Tang, J and Limlingan Malit, JJ and Wang, R and Sung, HH and Williams, ID and Qian, PY},
title = {Bathiapeptides: Polythiazole-Containing Peptides from a Marine Biofilm-Derived Bacillus sp.},
journal = {Journal of natural products},
volume = {},
number = {},
pages = {},
doi = {10.1021/acs.jnatprod.2c00290},
pmid = {35703501},
issn = {1520-6025},
abstract = {Bacteria in marine biofilms are a rich reservoir of natural products. To facilitate novel secondary metabolite discovery, we investigated the metabolic profile of a marine biofilm-derived Bacillus sp. B19-2 by combining bioinformatics and LC-UV-MS analyses. After dereplication and purification of putatively unknown compounds, a new family of compounds 1-8 was uncovered and named bathiapeptides. Structural elucidation using NMR, HRESIMS, ozonolysis, advanced Marfey's analysis, and X-ray diffraction revealed that bathiapeptides are polypeptides that contain a rare polythiazole moiety. These compounds exhibited strong cytotoxicity against Hep G2, HeLa, MCF-7, and MGC-803 cell lines, and the lowest IC50 value was 0.5 μM. An iterative biosynthesis logic in bathiapeptides' biosynthesis was proposed based on the identified chemical structures and putative gene cluster analysis.},
}
@article {pmid35703379,
year = {2022},
author = {Li, Q and Liu, J and Xu, Y and Liu, H and Zhang, J and Wang, Y and Sun, Y and Zhao, M and Liao, L and Wang, X},
title = {Fast Cross-Linked Hydrogel as a Green Light-Activated Photocatalyst for Localized Biofilm Disruption and Brush-Free Tooth Whitening.},
journal = {ACS applied materials &amp; interfaces},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsami.2c00887},
pmid = {35703379},
issn = {1944-8252},
abstract = {Biofilm-driven caries and tooth discoloration are two major problems in oral health care. The current methods have the disadvantages of insufficient biofilm targeting and irreversible enamel damage. Herein, an injectable sodium alginate hydrogel membrane doped with bismuth oxychloride (Bi12O17Cl2) and cubic cuprous oxide (Cu2O) nanoparticles was designed to simultaneously achieve local tooth whitening and biofilm removal through a photodynamic dental therapy process. This fast cross-linked hydrogel could form a biofilm removal coating on the target tooth surface precisely. Afterward, reactive oxygen species was effectively released on demand under green light, which could not only eradicate the biofilm but also whiten the tooth non-destructively in a facile manner without significant damage to both the enamel and biological cells. After the usage, the removal of this hydrogel can also enhance the effect of biofilm destruction and caries prevention.},
}
@article {pmid35700910,
year = {2022},
author = {Park, S and Lee, ES and Jung, HI and Kim, BI},
title = {Optical detection of oral biofilm in hospitalized geriatric patients using quantitative light-induced fluorescence technology.},
journal = {Photodiagnosis and photodynamic therapy},
volume = {},
number = {},
pages = {102962},
doi = {10.1016/j.pdpdt.2022.102962},
pmid = {35700910},
issn = {1873-1597},
abstract = {Detection and removal of pathological oral biofilm are essential in hospitalized geriatric patients as the biofilm can lead to lung infection. However, as elderly patients often have cognitive and physical impairments, general oral examination is complicated and detection of pathological biofilms is challenging. Quantitative light-induced fluorescence (QLF) technology, which is currently actively used to detect bacterial structures in the oral cavity, is used to detect dental biofilm and to identify various oral bacterial infections. We confirmed the applicability of QLF technology to oral hygiene assessment and evaluation of hospitalized geriatric patients using the QLF technology to detect and remove the pathological oral biofilm in a hospitalized geriatric patient. The oral biofilm attached to the oral mucosa was difficult to observe with the naked eye. However, it was detected with red fluorescence on QLF images, which helped us observe the to detect pathological oral biofilm and evaluate the effectiveness of oral hygiene care (OHC). After OHC, the strong red fluorescence expressed in the oral mucosa was no longer observed. This change in the clinical aspect of red fluorescence suggests that QLF can be used to detect pathological oral biofilm accumulated on the oral mucous membrane and evaluate the effectiveness of OHC in hospitalized patients with extremely poor oral hygiene.},
}
@article {pmid35700566,
year = {2022},
author = {Gujinović, L and Maravić, A and Kalinić, H and Dželalija, M and Šestanović, S and Zanchi, D and Šamanić, I},
title = {Metagenomic analysis of pioneer biofilm-forming marine bacteria with emphasis on Vibrio gigantis adhesion dynamics.},
journal = {Colloids and surfaces. B, Biointerfaces},
volume = {217},
number = {},
pages = {112619},
doi = {10.1016/j.colsurfb.2022.112619},
pmid = {35700566},
issn = {1873-4367},
abstract = {Marine biofilms occur frequently and spontaneously in seawater, on almost any submerged solid surface. At the early stages of colonization, it consists of bacteria and evolves into a more complex community. Using 16S rRNA amplicon sequencing and comparative metagenomics, the composition and predicted functional potential of one- to three-day old bacterial communities in surface biofilms were investigated and compared to that of seawater. This confirmed the autochthonous marine bacterium Vibrio gigantis as an early and very abundant biofilm colonizer, also functionally linked to the genes associated with cell motility, surface attachment, and communication via signaling molecules (quorum sensing), all crucial for biofilm formation. The dynamics of adhesion on a solid surface of V. gigantis alone was also monitored in controlled laboratory conditions, using a newly designed and easily implementable protocol. Resulting in a calculated percentage of bacteria-covered surface, a convincing tendency of spontaneous adhering was confirmed. From the multiple results, its quantified and reproducible adhesion dynamics will be used as a basis for future experiments involving surface modifications and coatings, with the goal of preventing adhesion.},
}
@article {pmid35700313,
year = {2022},
author = {Li, P and Yu, M and Ke, X and Gong, X and Li, Z and Xing, X},
title = {Cytocompatible Amphipathic Carbon Quantum Dots as Potent Membrane-Active Antibacterial Agents with Low Drug Resistance and Effective Inhibition of Biofilm Formation.},
journal = {ACS applied bio materials},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsabm.2c00292},
pmid = {35700313},
issn = {2576-6422},
abstract = {It is very challenging to design nanomaterials with both excellent antibacterial activity and cytocompatibility when facing bacterial infection. Here, inspired by antimicrobial peptides (AMPs), we fabricate carbon quantum dots (CQDs) derived from hydrophobic tryptophan and hydrophilic lysine or arginine (Lys/Trp-CQDs and Arg/Trp-CQDs), which possess amphipathic properties. These CQDs could effectively destroy bacterial membranes without developing resistance, inhibit biofilms formed by Staphylococcus aureus, and exhibit good in vitro biocompatibility. The antibacterial activities are caused by not only surface cationic structures and excess intracellular reactive oxygen species (ROS) generated by the CQDs but also the effects of the surface hydrophobic groups. These combined mechanisms of actions lead to bacterial membrane disruption, which raises the hope for combating bacterial infection without concern about drug resistance. What's more, the effect of amphiphilicity on balancing sterilization with biocompatibility expands the research ideas for developing available antibacterial nanomaterials.},
}
@article {pmid35700135,
year = {2022},
author = {Deng, Z and Hou, K and Valencak, TG and Luo, XM and Liu, J and Wang, H},
title = {AI-2/LuxS Quorum Sensing System Promotes Biofilm Formation of Lactobacillus rhamnosus GG and Enhances the Resistance to Enterotoxigenic Escherichia coli in Germ-Free Zebrafish.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0061022},
doi = {10.1128/spectrum.00610-22},
pmid = {35700135},
issn = {2165-0497},
abstract = {The LuxS enzyme plays a key role in both quorum sensing (QS) and the regulation of bacterial growth. It catalyzes the production of autoinducer-2 (AI-2) signaling molecule, which is a component of the methyl cycle and methionine metabolism. This study aimed at investigating the differences between the Lactobacillus rhamnosus GG (LGG) wild-type strain (WT) and its luxS mutant (ΔluxS) during biofilm formation and when resisting to inflammation caused by Enterotoxigenic Escherichia coli (ETEC) in germ-free zebrafish. Our results suggest that in the absence of luxS when LGG was knocked out, biofilm formation, extracellular polysaccharide secretion and adhesion were all compromised. Addition of synthetic AI-2 indeed rescued, at least partially, the deficiencies observed in the mutant strain. The colonizing and immunomodulatory function in WT versus ΔluxS mutants were further studied in a germ-free zebrafish model. The concentration of AI-2 signaling molecules decreased sharply in zebrafish infected with the ΔluxS. At the same time, compared with the ΔluxS, the wild-type strain could colonize the germ-free zebrafish more effectively. Our transcriptome results suggest that genes involved in immunity, signal transduction, and cell adhesion were downregulated in zebrafish infected with ΔluxS and WT. In the WT, the immune system of germ-free zebrafish was activated more effectively through the MAPK and NF-κB pathway, and its ability to fight the infection against ETEC was increased. Together, our results demonstrate that the AI-2/LuxS system plays an important role in biofilm formation to improve LGG and alleviate inflammation caused by ETEC in germ-free zebrafish. IMPORTANCE Lactobacillus rhamnosus GG is a widely used probiotic to improve host intestinal health, promote growth, reduce diarrhea, and modulate immunity. In recent years, the bacterial quorum sensing system has attracted much attention; however, there has not been much research on the effect of the LuxS/AI-2 quorum sensing system of Lactobacillus on bacteriostasis, microbial ecology balance, and immune regulation in intestine. In this study, we used germ-free zebrafish as an animal model to compare the differences between wild-type and luxS mutant strains. We showed how AI-2/LuxS QS affects the release of AI-2 and how QS regulates the colonization, EPS synthesis and biofilm formation of LGG. This study provides an idea for the targeted regulation of animal intestinal health with probiotics by controlling bacteria quorum sensing system.},
}
@article {pmid35699894,
year = {2022},
author = {Lauková, A and Chrastinová, Ľ and Micenková, L and Bino, E and Kubašová, I and Kandričáková, A and Gancarčíková, S and Plachá, I and Holodová, M and Grešáková, Ľ and Formelová, Z and Simonová, MP},
title = {Enterocin M in Interaction in Broiler Rabbits with Autochthonous, Biofilm-Forming Enterococcus hirae Kr8 Strain.},
journal = {Probiotics and antimicrobial proteins},
volume = {},
number = {},
pages = {},
pmid = {35699894},
issn = {1867-1314},
abstract = {Young rabbits are susceptible to gastrointestinal diseases caused by bacteria. Enterococcus hirae can be associated with diseases. But enterocins produced by some enterococcal species can prevent/reduce this problem. Therefore, the interaction of enterocin M with a biofilm-forming, autochthonous E. hirae Kr8+ strain was tested in rabbits to assess enterocin potential in vivo. Rabbits (96), aged 35 days, both sexes, meat line M91 breed were divided into four groups, control C and three experimental groups. The rabbits in C received the standard diet, rabbits in experimental group 1 (E1) received 108 CFU/mL of Kr8+, a dose 500 µL/animal/day, E2 received Ent M (50 µL/animal/day), and E3 received both Kr8+ and Ent M in their drinking water over 21 days. The experiment lasted 42 days. Feces and blood were sampled at day 0/1 (at the start of the experiment, fecal mixture of 96 animals, n = 10), at day 21 (five fecal mixtures per group, n = 5), and at day 42 (21 days after additives cessation, the same). At days 21 and 42, four rabbits from each group were slaughtered, and cecum and appendix were sampled for standard microbial analysis. Ent M showed decreased tendency of Kr8+. Using next-generation sequencing, the phyla detected with the highest abundance were Firmicutes, Verrucomicrobia, Bacteroidetes, Tenericutes, Proteobacteria, Cyanobacteria, Saccharibacteria, and Actinobacteria. Interaction of Ent M with some phyla resulted in reduced abundance percentage. At day 21, significantly increased phagocytic activity (PA) was found in E1 and E2 (p < 0.001). Kr8+ did not attack PA and did not stimulate oxidative stress. But Ent M supported PA. The prospective importance of this study lies in beneficial interaction of enterocin in host body.},
}
@article {pmid35699787,
year = {2022},
author = {Xu, JG and Hu, HX and Chen, JY and Xue, YS and Kodirkhonov, B and Han, BZ},
title = {Comparative study on inhibitory effects of ferulic acid and p-coumaric acid on Salmonella Enteritidis biofilm formation.},
journal = {World journal of microbiology &amp; biotechnology},
volume = {38},
number = {8},
pages = {136},
pmid = {35699787},
issn = {1573-0972},
support = {2017YFC1600806//Key Technologies Research and Development Program/ ; 2020TC116//Chinese Universities Scientific Fund/ ; },
abstract = {Biofilm cells exhibit higher resistance than their planktonic counterparts to commonly used disinfectants in food industry. Phenolic acids are promising substitute offering less selective pressure than traditional antibiotics. This study aims to evaluate the inhibitory effects of ferulic acid (FA) and p-coumaric acid (p-CA) on Salmonella Enteritidis biofilm formation and explore the underlying inhibitory mechanisms. The minimal inhibitory concentration (MIC) of FA and p-CA were 1.0 and 0.5 mg/ml, respectively. The sub-inhibitory concentration (1/8 MIC) significantly decreased biofilm formation without growth inhibitory effects. The biomass and extracellular polymeric substances (EPS) of S. Enteritidis biofilm as well as the bacterial swimming and chemotaxis abilities were significantly decreased when exposed to sub-MIC concentrations of FA and p-CA. These two phenolic acids showed high affinity to proteins involved in flagella motility and repressed the S. Enteritidis biofilm formation-related gene expressions. Furthermore, these two phenolic acids maintained high antibiofilm efficiency in simulated food processing conditions. This study provided valuable information of multiple phenotypic and molecular responses of S. Enteritidis to these two phenolic acids.},
}
@article {pmid35699414,
year = {2022},
author = {Ravel, G and Bergmann, M and Trubuil, A and Deschamps, J and Briandet, R and Labarthe, S},
title = {Inferring characteristics of bacterial swimming in biofilm matrix from time-lapse confocal laser scanning microscopy.},
journal = {eLife},
volume = {11},
number = {},
pages = {},
doi = {10.7554/eLife.76513},
pmid = {35699414},
issn = {2050-084X},
support = {ANR-12-ALID-0006//Agence Nationale de la Recherche/ ; },
abstract = {Biofilms are spatially organized communities of microorganisms embedded in a self-produced organic matrix, conferring to the population emerging properties such as an increased tolerance to the action of antimicrobials. It was shown that some bacilli were able to swim in the exogenous matrix of pathogenic biofilms and to counterbalance these properties. Swimming bacteria can deliver antimicrobial agents in situ, or potentiate the activity of antimicrobial by creating a transient vascularization network in the matrix. Hence, characterizing swimmer trajectories in the biofilm matrix is of particular interest to understand and optimize this new biocontrol strategy in particular, but also more generally to decipher ecological drivers of population spatial structure in natural biofilms ecosystems. In this study, a new methodology is developed to analyze time-lapse confocal laser scanning images to describe and compare the swimming trajectories of bacilli swimmers populations and their adaptations to the biofilm structure. The method is based on the inference of a kinetic model of swimmer populations including mechanistic interactions with the host biofilm. After validation on synthetic data, the methodology is implemented on images of three different species of motile bacillus species swimming in a Staphylococcus aureus biofilm. The fitted model allows to stratify the swimmer populations by their swimming behavior and provides insights into the mechanisms deployed by the micro-swimmers to adapt their swimming traits to the biofilm matrix.},
}
@article {pmid35698852,
year = {2022},
author = {Protasiuk, LE and Serov, NS and Lokteva, AV and Kladko, DV and Koshel, EI and Vinogradov, VV},
title = {Mechano-bactericidal anisotropic particles for oral biofilm treatment.},
journal = {Journal of materials chemistry. B},
volume = {},
number = {},
pages = {},
doi = {10.1039/d2tb00582d},
pmid = {35698852},
issn = {2050-7518},
abstract = {Bacterial biofilms play a major etiological role in dental diseases worldwide. Currently, toothpastes with bactericidal chemicals and abrasive materials are used as preventive care methods. However, chemicals can cause adverse side effects, with the use of antibiotics, fluorides, and antiseptics drastically reducing quality of life. At the same time, the rational design of bulk toothpaste materials has remained unexplored. In this work, we demonstrated a mechano-bactericidal strategy as an antibiotic-free and tooth-safe approach for dental biofilm elimination based on shape-anisotropy CaCO3 (cubic-, stick-, and urchin-shaped). As proof-of-concept, we demonstrated superior efficiency during biofilm eradication from ex vivo teeth using urchin- and stick-shaped microparticles involving both Escherichia coli K12 (227 ± 32.6% and 215 ± 33%, respectively) and Staphylococcus aureus ATCC 209P (210 ± 54.7% and 202 ± 55.5%, respectively) compared to the spherical particles that are employed in conventional toothpastes. These findings will potentially give rise to the development of novel and safer toothpastes with antibiotic-free bactericidal activity for the prevention of dental diseases.},
}
@article {pmid35698329,
year = {2022},
author = {Vandana, and Das, S},
title = {Genetic regulation, biosynthesis and applications of extracellular polysaccharides of the biofilm matrix of bacteria.},
journal = {Carbohydrate polymers},
volume = {291},
number = {},
pages = {119536},
doi = {10.1016/j.carbpol.2022.119536},
pmid = {35698329},
issn = {1879-1344},
abstract = {Bacterial biofilm formation is dependent mainly on the decision-making process of the two key factors of the gene regulatory network, namely the Quorum Sensing (QS) system and bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP). c-di-GMP is a secondary messenger molecule that enhances extracellular polysaccharides production by activating pelD and alg44. Genes involved in the metabolic pathway for the biosynthesis of extracellular polysaccharides are clustered within the genome of the producing bacteria. The extracellular polysaccharide gene cluster encodes specific regulatory enzymes and transporter proteins involved in the different steps of the biosynthesis route. The diversity of extracellular polysaccharides produced by the bacteria is synthesized via different biosynthesis pathways. Understanding the genetic regulation and biosynthesis of extracellular polysaccharides is crucial for tailor-made polymers via genetic, metabolic, and protein engineering approaches. This review illustrates structure, structure-function relationship, genetics, regulation, biosynthetic pathways, and various applications of extracellular polysaccharides.},
}
@article {pmid35696784,
year = {2022},
author = {Deng, YH and Ricciardulli, T and Won, J and Wade, MA and Rogers, SA and Boppart, SA and Flaherty, DW and Kong, H},
title = {Self-locomotive, antimicrobial microrobot (SLAM) swarm for enhanced biofilm elimination.},
journal = {Biomaterials},
volume = {287},
number = {},
pages = {121610},
doi = {10.1016/j.biomaterials.2022.121610},
pmid = {35696784},
issn = {1878-5905},
abstract = {Biofilm is a major cause of infections and infrastructure deterioration, largely due to molecular diffusion restrictions that hamper the antimicrobial activity of traditional antibiotics and disinfectants. Here, we present a self-locomotive, antimicrobial microrobot (SLAM) swarm that can penetrate, fracture, and detach biofilm and, in turn, nullify bacterial resistance to antibiotics. The SLAM is assembled by loading a controlled mass of manganese oxide nanosheets on diatoms with the polydopamine binder. In hydrogen peroxide solution, SLAMs produce oxygen bubbles that generate thrust to penetrate the rigid and dense Pseudomonas aeruginosa biofilm and self-assemble into a swarm that repeatedly surrounds, expands, and bursts oxygen bubbles. The resulting cavities continue to deform and fracture extracellular polymeric substances from microgrooved silicone substrates and wounded skin explants while decreasing the number of viable bacterial cells. Additionally, SLAM allows irrigating water or antibiotics to access the residual biofilm better, thus enhancing the synergistic efficacy in killing up to 99.9% of bacterial cells.},
}
@article {pmid35695502,
year = {2022},
author = {Chapartegui-González, I and Khakhum, N and Stockton, JL and Torres, AG},
title = {Evaluating the Contribution of the Predicted Toxin-Antitoxin System HigBA to Persistence, Biofilm Formation, and Virulence in Burkholderia pseudomallei.},
journal = {Infection and immunity},
volume = {},
number = {},
pages = {e0003522},
doi = {10.1128/iai.00035-22},
pmid = {35695502},
issn = {1098-5522},
abstract = {Melioidosis is an underreported human disease caused by the Gram-negative intracellular pathogen Burkholderia pseudomallei (Bpm). Both the treatment and the clearance of the pathogen are challenging, with high relapse rates leading to latent infections. This has been linked to the bacterial persistence phenomenon, a growth arrest strategy that allows bacteria to survive under stressful conditions, as in the case of antibiotic treatment, within a susceptible clonal population. At a molecular level, this phenomenon has been associated with the presence of toxin-antitoxin (TA) systems. We annotated the Bpm K96243 genome and selected 11 pairs of genes encoding for these TA systems, and their expression was evaluated under different conditions (supralethal antibiotic conditions; intracellular survival bacteria). The predicted HigB toxin (BPSL3343) and its predicted antitoxin HigA (BPS_RS18025) were further studied using mutant construction. The phenotypes of two mutants (ΔhigB and ΔhigB ΔhigA) were evaluated under different conditions compared to the wild-type (WT) strain. The ΔhigB toxin mutant showed a defect in intracellular survival on macrophages, a phenotype that was eliminated after levofloxacin treatment. We found that the absence of the toxin provides an advantage over the WT strain, in both in vitro and in vivo models, during persister conditions induced by levofloxacin. The lack of the antitoxin also resulted in differential responses to the conditions evaluated, and under some conditions, it restored the WT phenotype, overall suggesting that both toxin and antitoxin components play a role in the persister-induced phenotype in Bpm.},
}
@article {pmid35695458,
year = {2022},
author = {Hjort, K and Fermér, E and Tang, PC and Andersson, DI},
title = {Antibiotic Minimal Selective Concentrations and Fitness Costs during Biofilm and Planktonic Growth.},
journal = {mBio},
volume = {},
number = {},
pages = {e0144722},
doi = {10.1128/mbio.01447-22},
pmid = {35695458},
issn = {2150-7511},
abstract = {The use and misuse of antibiotics have resulted in the selection of difficult-to-treat resistant bacteria. Two key parameters that influence the selection of resistant bacteria are the minimal selective concentration (MSC) and the fitness cost of resistance, both of which have been measured during planktonic growth in several studies. However, bacterial growth most often occurs in biofilms, and it is unclear if and how these parameters differ under these two growth conditions. To address this knowledge gap, we compared a selection of several types of antibiotic-resistant Escherichia coli mutants during planktonic and biofilm growth to determine the fitness costs and MSCs. Biofilm-forming Escherichia coli strains are commonly found in catheter-associated and recurrent urinary tract infections. Isogenic strains of a biofilm-forming E. coli strain, differing only in the resistance mechanisms and the fluorescent markers, were constructed, and susceptible and resistant bacteria were grown in head-to-head competitions at various concentrations of antibiotics under planktonic and biofilm conditions. Mutants with resistance to five different antibiotics were studied. The results show that during both planktonic and biofilm growth, selection for the resistant mutants occurred for all antibiotics at sub-MICs far below the MIC of the antibiotic. Even though differences were seen, the MSC values and the fitness costs did not differ systematically between planktonic and biofilm growth, implying that despite the different growth modes, the basic selection parameters are similar. These findings highlight the risk that resistant mutants may, similarly to planktonic growth, also be selected at sub-MICs of antibiotics in biofilms. IMPORTANCE Our understanding of how and where antibiotic resistance is selected in response to antibiotic exposure is still limited, and this is particularly true for selective processes when bacteria are growing in biofilms, arguably the most significant mode of growth of bacteria in human and animal infections as well as in other settings. In this study, we compared how different types of resistant E. coli strains were selected in response to antibiotic exposure during planktonic and biofilm growth. Determination of the minimal selective concentrations (MSCs) and fitness costs of resistance showed that they were comparable under these two different conditions, even though some differences were observed. Importantly, the MSCs were far below the MICs for all mutants under both planktonic and biofilm growth, emphasizing the significance of low antibiotic concentrations in driving the emergence and enrichment of resistant bacteria.},
}
@article {pmid35695457,
year = {2022},
author = {Dodson, TA and Carlson, EA and Wamer, NC and Morse, CN and Gadient, JN and Prestwich, EG},
title = {Characterization of Distinct Biofilm Cell Subpopulations and Implications in Quorum Sensing and Antibiotic Resistance.},
journal = {mBio},
volume = {},
number = {},
pages = {e0019122},
doi = {10.1128/mbio.00191-22},
pmid = {35695457},
issn = {2150-7511},
abstract = {Bacteria change phenotypically in response to their environment. Free swimming cells transition to biofilm communities that promote cellular cooperativity and resistance to stressors and antibiotics. We uncovered three subpopulations of cells with diverse phenotypes from a single-species Pseudomonas aeruginosa PA14 biofilm, and used a series of steps to isolate, characterize, and map these cell subpopulations in a biofilm. The subpopulations were distinguishable by size and morphology using dynamic light scattering (DLS) and scanning electron microscopy (SEM). Additionally, growth and dispersal of biofilms originating from each cell subpopulation exhibited contrasting responses to antibiotic challenge. Cell subpopulation surface charges were distinctly different, which led us to examine the ionizable surface molecules associated with each subpopulation using mass spectrometry. Matrix assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry analysis of cell subpopulations revealed ions unique to each subpopulation of cells that significantly co-localized with ions associated with quorum sensing. Transcript levels of algR, lasR, and rhlI in subpopulations isolated from biofilms differed from levels in planktonic stationary and mid-log cell subpopulations. These studies provide insight into diverse phenotypes, morphologies, and biochemistries of PA14 cell subpopulations for potential applications in combating bacterial pathogenesis, with medical, industrial, and environmental complications. IMPORTANCE Pseudomonas aeruginosa biofilms can cause chronic infections in burn wounds, grow on medical equipment, and proliferate in the lungs of people with cystic fibrosis. These inherently antibiotic tolerant biofilms are difficult to eradicate largely due to the complexity of the biofilm environment. Developing more effective biofilm treatments is reliant upon understanding biofilm heterogeneity. We identified and characterized three separate cell subpopulations found in P. aeruginosa PA14 biofilms. The distinct morphologies, phenotypes, and biochemistries of each of these cell subpopulations indicate that they contribute differently to the overall biofilm environment. These findings demonstrate that bacterial cells of the same species exhibit diversity that implies distinct roles in biofilm initiation, maturation, and maintenance.},
}
@article {pmid35693228,
year = {2022},
author = {Peerzada, Z and Kanhed, AM and Desai, KB},
title = {Effects of active compounds from Cassia fistula on quorum sensing mediated virulence and biofilm formation in Pseudomonas aeruginosa.},
journal = {RSC advances},
volume = {12},
number = {24},
pages = {15196-15214},
doi = {10.1039/d1ra08351a},
pmid = {35693228},
issn = {2046-2069},
abstract = {Pseudomonas aeruginosa infections are attributed to its ability to form biofilms and are difficult to eliminate with antibiotic treatment. Biofilm formation is regulated by quorum sensing (QS), an intracellular bacterial communication mechanism that allows the activation of numerous virulence factors and secondary metabolites. Targeting the QS pathway is a potential approach that prevents QS-controlled phenotypes and biofilm formation. For the first time, the current work has identified antiquorum sensing activity in the partially purified four fractions from the hot ethyl acetate extract of Cassia fistula fruit pods. Of the four fractions, only fraction-1 gave decreased AHL activity; the phytoconstituents in this fraction were identified as rhein, 3-aminodibenzofuran, 5-(hydroxymethyl)-2-(dimethoxymethyl)furan, and dihydrorhodamine. Fraction-1 (1 mg ml-1) and rhein (0.15 mg ml-1) showed 63% and 42.7% reduction in short-chain AHL production, respectively, without hindering the bacterial growth. Fraction-1 inhibited QS-mediated extracellular virulence factors viz. protease, elastase, pyocyanin, and rhamnolipid (p < 0.05). Quantitative analysis of biofilm formation showed 77% &amp; 62.4% reduction by fraction-1 (1 mg ml-1) and rhein (0.15 mg ml-1) respectively. Confocal laser microscopy (CLMS) &amp; scanning electron microscopy (SEM) confirmed the reduction of biofilm formation in Pseudomonas aeruginosa upon treatment with fraction-1 and rhein. Moreover, the in vivo study displayed that fraction-1 and rhein (standard) significantly enhanced the survival of Caenorhabditis elegans by suppressing the potency of virulence factors of Pseudomonas aeruginosa. Quantitative real-time polymerase chain reaction results demonstrated the down-regulation of QS-related genes, lasI, lasR, rhlI, and rhlR. In addition, in silico analysis divulged that a component identified by GC-MS displayed a strong affinity towards LasI and LasR. These findings suggest that potent phytochemicals from fraction-1, including rhein, could serve as novel phytotherapeutics in controlling emerging infections of antibiotic-resistant bacterial pathogens like Pseudomonas aeruginosa.},
}
@article {pmid35691511,
year = {2022},
author = {Hennequin, C and Forestier, C and Traore, O and Debroas, D and Bricheux, G},
title = {Plasmidome analysis of a hospital effluent biofilm: Status of antibiotic resistance.},
journal = {Plasmid},
volume = {},
number = {},
pages = {102638},
doi = {10.1016/j.plasmid.2022.102638},
pmid = {35691511},
issn = {1095-9890},
abstract = {Plasmids are widely involved in the dissemination of characteristics within bacterial communities. Their genomic content can be assessed by high-throughput sequencing of the whole plasmid fraction of an environment, the plasmidome. In this study, we analyzed the plasmidome of a biofilm formed in the effluents of the teaching hospital of Clermont-Ferrand (France). Our analysis discovered >350 new complete plasmids, with a length ranging from 1219 to 40,193 bp. Forty-two plasmid incompatibility (Inc) groups were found among all the plasmid contigs. Ten large plasmids, described here in detail, were reconstructed from plasmid contigs, seven of which carried antibiotic resistance genes. Four plasmids potentially confer resistance to numerous families of antibiotics, including carbapenems, aminoglycosides, colistin, and chloramphenicol. Most of these plasmids were affiliated to Proteobacteria, a phylum of Gram-negative bacteria. This study therefore illustrates the composition of an environmental mixed biofilm in terms of plasmids and antibiotic resistance genes.},
}
@article {pmid35690659,
year = {2022},
author = {Tran, VN and Khan, F and Han, W and Luluil, M and Truong, VG and Yun, HG and Choi, S and Kim, YM and Shin, JH and Kang, HW},
title = {Real-time monitoring of mono- and dual-species biofilm formation and eradication using microfluidic platform.},
journal = {Scientific reports},
volume = {12},
number = {1},
pages = {9678},
pmid = {35690659},
issn = {2045-2322},
support = {No. 2021R1A2C2003733//National Research Foundation of Korea/ ; },
abstract = {In a human host, bacterial Staphylococcus aureus and fungal Candida albicans pathogens form a mixed biofilm that causes severe mortality and morbidity. However, research on the formation and eradication of mixed biofilms under dynamic conditions is lacking. Thus, this study employed a microfluidic technique to analyze the real-time formation of mono- and dual-species (S. aureus and C. albicans) biofilms and noninvasive optical treatment of the established mature biofilm using 405-nm laser light. A herringbone mixer thoroughly mixed both bacterial and fungal cells in the growth media before being injected into the observation channels on the microfluidic chip. At a flow rate of 1.0 µL/min of growth media for 24 h, the bacterial biofilm coverage was up to 15% higher than that of the fungal biofilm (50% for bacteria vs. 35% for fungus). On the other hand, the dual-species biofilm yielded the highest coverage of ~ 96.5% because of the collective interaction between S. aureus and C. albicans. The number of cell proliferation events in S. aureus was higher than that of C. albicans for 12 h, which indicates that the S. aureus biofilm was developed faster than C. albicans. The novel in situ test platform showed a significant bactericidal effect (80%) of the 405-nm laser light at 1080 J/cm2 towards the established S. aureus biofilm, whereas the same treatment removed approximately 69% of the mixed cells in the dual-species biofilm. This study revealed that the developed microfluidic platform could be utilized to monitor the formation of dual-species biofilms in real-time and laser-induced antimicrobial effects on dual-species biofilms.},
}
@article {pmid35690445,
year = {2022},
author = {Lee, S and Chen, J},
title = {Identification of the genetic elements involved in biofilm formation by Salmonella enterica serovar Tennessee using mini-Tn10 mutagenesis and DNA sequencing.},
journal = {Food microbiology},
volume = {106},
number = {},
pages = {104043},
doi = {10.1016/j.fm.2022.104043},
pmid = {35690445},
issn = {1095-9998},
abstract = {Biofilms are known to contribute to bacterial tolerance to desiccation and survival in low moisture foods. However, the molecular mechanisms underlying biofilm formation have not been fully elucidated. This study identified some of the genes that are implicated in biofilm formation by Salmonella enterica serovar Tennessee, the "peanut butter outbreak" strain. Mini-Tn10 mutagenesis was used in the study to generate random transposon insertion libraries. The ability of selected mutants in forming biofilms was compared with their wildtype parent using the crystal violet binding assay. Mutants forming significantly less (P ≤ 0.05) biofilm compared to their wildtype parent were selected for whole-genome sequencing. Mini-Tn10 insertion sites on mutant genomes were identified by comparing the acquired sequencing data with those in the Genbank using the BLAST search. In total, 56 mutants were obtained, and five were selected for further analysis according to the result of the biofilm assay. Sequencing analysis revealed that the mini-Tn10 interrupted the S. enterica genes that encode bacterial cell membrane lipoprotein, DNA topoisomerase III, attachment and invasion locus protein, bacteriocin immunity protein, and cell division protein. The information generated from the research should be useful in the control fo S. enterica in low-moisture foods and their production environments.},
}
@article {pmid35690237,
year = {2022},
author = {Raj Deena, S and Kumar, G and Vickram, AS and Rani Singhaniam, R and Dong, CD and Rohini, K and Anbarasu, K and Thanigaivel, S and Kumar Ponnusamy, V},
title = {Efficiency of Various Biofilm Carriers and Microbial Interactions with Substrate in Moving Bed-Biofilm Reactor for Wastewater Treatment: A Review.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {127421},
doi = {10.1016/j.biortech.2022.127421},
pmid = {35690237},
issn = {1873-2976},
abstract = {In a moving bed-biofilm reactor (MBBR), the fluidization efficiency, immobilization of microbial cells, and treatment efficiency are directly influenced by the shape and pores of biofilm carriers. Moreover, the efficacy of bioremediation mainly depends on their interaction interface with microbes and substrate. This review aims to comprehend the role of different carrier properties such as material shapes, pores, and surface area on bioremediation productivity. A porous biofilm carrier with surface ridges containing spherical pores sizes >1 mm can be ideal for maximum efficacy. It provides diverse environments for cell cultures, develops uneven biofilms, and retains various cell sizes and biomass. Moreover, the thickness of biofilm and controlled scaling shows a significant impact on MBBR performance. Therefore, the effect of these parameters in MBBR is discussed detailed in this review, through which existing literature and technical strategies that focus on the surface area as the primary factor can be critically assessed.},
}
@article {pmid35689970,
year = {2022},
author = {Cabo, ML and Rodríguez, A and Herrera, JR},
title = {Exploring communication signals inside the microbial community of a Listeria monocytogenes-carrying biofilm contamination site.},
journal = {International journal of food microbiology},
volume = {376},
number = {},
pages = {109773},
doi = {10.1016/j.ijfoodmicro.2022.109773},
pmid = {35689970},
issn = {1879-3460},
abstract = {In nature, bacterial pathogens like L. monocytogenes, live in nature associated with other microbial species in spatially-structured communities called biofilms. In the food industry, biofilms contribute to the survival and persistence of L. monocytogenes within processing facilities, thereby enhancing its risk of cross-contaminating food products. The challenge of combating biofilms has triggered the search for new antibiofilm strategies including devising ways to interfere with cell communication mechanisms (quorum-sensing) that are known to be involved with biofilm development regulation. The aim of this study was to explore cell communication signals in a L. monocytogenes-carrying microbial community isolated from a meat processing plant (location No. 96) in order to elucidate the ecological interactions that could serve as a starting point for the development of new antibiofilm strategies. Quorum quenching (QQ) and quorum sensing (QS) activities were screened among 31 bacterial strains isolated from location No. 96. Whereas no QQ activity was detected against short-chain lactone N-hexanoyl-DL-homoserine lactone (C6-HSL), it was detected against N-dodecanoyl-DL-homoserine lactone (C12-HSL) in 7 isolates (23%), particularly in Pseudomonas monteilli, Rhodococcus sp. and Rhodococcus erythropolis. QS activity assays detected HC4, C4, C6, OC6, HC10 and C16 in all the extracts, being C4, C6 and OC6 with predominantly produced by Pseudomonas monteilli, Pseudomonas gesardii, Psychrobacter maritimus and Paracoccus sp. High production levels of C16-HSL by Paracoccus sp. and the role of this long-chain lactone as a self-inhibitor of cell aggregation led us to carry out further studies focused on the effects of a Paracoccus lactone extract (PLE) against the biofilm formation by L. monocytogenes. A quantitative microscopic analysis demonstrated a significant decrease (p < 0.05) in the area occupied by biofilms formed on stainless steel (SS) coupons by different strains of L. monocytogenes in the presence of PLEs. Conversely, no significant differences were observed in the total number of viable adhered cells on SS coupons with or without PLE. The observed effect was partially reproduced by the addition of pure C16-HSL to 24 h-biofilms of L. monocytogenes L1.96. These results demonstrate that the observed effects can be attributed, at least partially, to the HSLs contained in the PLE. Overall, the present results highlight how interspecies communication within a biofilm can open up new insights for the development of new ways to combat biofilm.},
}
@article {pmid35689422,
year = {2022},
author = {Ribeiro, M and Gomes, IB and Saavedra, MJ and Simões, M},
title = {Photodynamic therapy and combinatory treatments on the control of biofilm-associated infections.},
journal = {Letters in applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/lam.13762},
pmid = {35689422},
issn = {1472-765X},
abstract = {The advent of antimicrobial resistance has added considerable impact to infectious diseases both in number of infections and healthcare costs. Furthermore, the relentless emergence of multidrug-resistant bacteria, particularly in the biofilm state, has made mandatory the discovery of new alternative antimicrobial therapies that are capable to eradicate resistant bacteria and impair the development of new forms of resistance. Amongst the therapeutic strategies for treating biofilms, antimicrobial photodynamic therapy (aPDT) has shown great potential in inactivating several clinically relevant microorganisms, including antibiotic-resistant "priority bacteria" declared by the WHO as critical pathogens. Its antimicrobial effect is centered on the basis that harmless low-intensity light stimulates a non-toxic dye named photosensitizer (PS), triggering the production of reactive oxygen species (ROS) upon photostimulation. In addition, combination therapies of aPDT with other antimicrobial agents (e.g., antibiotics) have also drawn considerable attention, as it is a multi-target strategy. Therefore, the present review highlights the recent advances of aPDT against biofilms, also covering progresses on combination therapy.},
}
@article {pmid35688976,
year = {2022},
author = {Suganya, M and Preethi, PS and Narenkumar, J and Prakash, AA and Devanesan, S and AlSalhi, MS and Rajasekar, A and Nanthini, AUR},
title = {Synthesis of silver nanoparticles from Indian red yeast rice and its inhibition of biofilm in copper metal in cooling water environment.},
journal = {Environmental science and pollution research international},
volume = {},
number = {},
pages = {},
pmid = {35688976},
issn = {1614-7499},
abstract = {The development of environmentally acceptable benign techniques using purely natural methods is a cost-effective procedure with long-term benefits in all areas. With this consideration, myco synthesized silver nano particles (AgNPs) were studied and it acted as an impending corrosion inhibitor in the environment. Initially, AgNPs were evaluated by physical and surface characterizations and this evidence demonstrated that RYRE's water-soluble molecules played an essential role in the synthesis of AgNPs in nano spherical size. The myco synthesized of AgNPs has showed an antibacterial activity against corrosive bacteria in cooling water system (CWS). Hence, the AgNPs were used in biocorrosion studies as an anticorrosive agent along with AgNO3 and RYRE was also checked. For this experiment, the copper (Cu) metal (CW024) which is commonly used was selected, the result of corrosion rate was decreased, and inhibition efficiency (82%) was higher in the presence of AgNPs in system IV. Even though, AgNO3 and RYRE had contributed significant inhibition efficiency on Cu at 47% and 61%, respectively. According to XRD, the reaction of AgNPs on Cu metal resulted in the formation of a protective coating of Fe2O3 against corrosion. EIS data also indicated that it could reduce the corrosion on the Cu metal surface. All of these findings point out the possibility that the myco-synthesized AgNPs were an effective copper metal corrosion inhibitor. As a result, we encourage the development of myco-synthesized AgNPs, which could be useful in the industrial settings.},
}
@article {pmid35688968,
year = {2022},
author = {Hu, J and Gu, Y and Lu, H and Raheem, MA and Yu, F and Niu, X and Zuo, J and Yin, H and Huang, C and Song, X and Tu, J and Zhou, W and Jiang, W and Chen, Z and Han, X and Qi, K},
title = {Identification of novel biofilm genes in avian pathogenic Escherichia coli by Tn5 transposon mutant library.},
journal = {World journal of microbiology &amp; biotechnology},
volume = {38},
number = {8},
pages = {130},
pmid = {35688968},
issn = {1573-0972},
support = {31872483//National Natural Science Foundation of China/ ; 31772707//National Natural Science Foundation of China/ ; 32072829//National Natural Science Foundation of China/ ; No.22ZR1475800//Natural Science Foundation of Shanghai/ ; No. 2021J011099//Natural Science Foundation of Fujian Province/ ; Grant No. 2021ZN001//Research Foundation for Advanced Talents of Ludong University/ ; },
abstract = {Avian pathogenic Escherichia coli (APEC) is the main pathogens that inflict the poultry industry. Biofilm as the pathogenic factors of APEC, which can enhance the anti-host immune system of APEC and improve its survival in the environment. In order to screen for new genes related to APEC biofilm. The APEC strain APEC81 was used to construct a mutant library by Tn5 insertion mutagenesis. Moreover the 28 mutant strains with severely weakened biofilm were successfully screened from 1500 mutant strains by crystal violet staining, in which 17 genes were obtained by high-efficiency thermal asymmetric interlaced PCR. The reported genes include 3 flagella genes (fliS, fliD, and fliR), 4 curli fimbriae genes (csgD, csgA, csgF, and csgG) and 3 type 1 fimbriae genes (fimA, fimD, and fimC). The novel genes include 3 coenzyme genes (gltA, bglX, and mltF) and 4 putative protein genes (yehE, 07045, 11735, 11255). To investigate whether these 17 genes co-regulate the biofilm, the 17 identified genes were deleted from APEC strain APEC81. The results showed that except for the 11735 and 11255 genes, the deletion of 15 genes significantly reduced the biofilm formation ability of APEC81 (P < 0.05). The result of rdar (red, dry and rough) colony morphology showed that curli fimbriae genes (csgD, csgA, csgF, and csgG) and other functional genes (fimC, glxK, yehE, 07045, and 11255) affected the colony morphology. In particular, the hypothetical protein YehE had the greatest influence on the biofilm. It was predicted to have the same structure as the type 1 fimbria protein. When yehE was deleted, the fimE transcription was up-regulated, and the fimA and fimB transcription were down-regulated, resulting in a decrease in type 1 fimbriae. Hence, the yehE mutant significantly reduced the biofilm and the adhesion and invasion ability to cells (P < 0.05). This study identified 5 novel genes (gltA, bglX, mltF, yehE, and 07045) related to biofilm formation and confirmed that yehE affects biofilm formation by type 1 fimbriae, which will benefit further study of the mechanism of biofilm regulation in APEC.},
}
@article {pmid35688188,
year = {2022},
author = {Ganesan, S and Limphattharachai, S and Chawengkijwanich, C and Liu, Y and Janjaroen, D},
title = {Influence of salinity on biofilm formation and COD removal efficiency in anaerobic moving bed biofilm reactors.},
journal = {Chemosphere},
volume = {},
number = {},
pages = {135229},
doi = {10.1016/j.chemosphere.2022.135229},
pmid = {35688188},
issn = {1879-1298},
abstract = {Anaerobic digestion is widely used for wastewater treatment, but this approach often relies on microbial communities that are adversely affected by high-salinity conditions. This study investigated the applicability of an anaerobic moving bed biofilm reactor (AMBBR) to treating high-salinity wastewater. The removal performance and microbial community were examined under salinity conditions of 1000-3000 mg/L, and a soluble chemical oxygen demand (sCOD) removal efficiency of up to 8% ± 2.74% was achieved at high-salinity. Scanning electron microscopy showed that microorganisms successfully attached onto the polyvinyl alcohol gel carrier, and the extracellular polymeric substances on the biofilm increased at higher salt concentrations. The AMBBR also maintained traditionally accepted levels of total alkalinity and volatile fatty acids for stable wastewater processing under these operating conditions. High-throughput sequencing indicated that Desulfomicrobium and three methanogenic groups were the dominant contributors to sCOD removal. Overall, the results showed that the AMBBR can successfully treat fish factory wastewater under varying salinity conditions.},
}
@article {pmid35687499,
year = {2022},
author = {Li, J and Wu, Y and Zhang, Q and Zhao, J and Zhang, H and Chen, W},
title = {Optimization of environmental factors in a dual in vitro biofilm model of Candida albicans - Streptococcus mutans.},
journal = {Letters in applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/lam.13761},
pmid = {35687499},
issn = {1472-765X},
abstract = {The biofilm formation of Streptococcus mutans-Candida albicans is an important virulence factor for dental caries. The purpose of this study was to determine the effect of some environmental conditions on the biofilm formation like inoculation concentration, temperature, sugar, amino acid, metal ions and saliva, and then establish a persistent in vitro biofilm model for further research. Based on the single factor experiment, the factors participating in the biofilm formation including sugar, inoculation concentration, and saliva increased the biofilm mass, while amino acid, metal ions, temperatures reduced biofilm mass. Optimal conditions for biofilm formation were the inoculation dosage of S. mutans and C. albicans of 108 and 107 , respectively, the addition of 0.3 g·L-1 sucrose and sterile saliva. These results contribute to a deep understanding of the factors involved in oral biofilm formation of the important cariogenic pathogen S. mutans and the opportunistic pathogen C. albicans to study better for biofilm and promote the design of new therapeutic approaches. The present research also provides a model for evaluating the therapeutic potential for drugs in the future.},
}
@article {pmid35686374,
year = {2022},
author = {Mehrnia, MR and Nasiri, F and Pourasgharian Roudsari, F and Bahrami, F},
title = {Hybrid powdered activated carbon-activated sludge biofilm formation to mitigate biofouling in dynamic membrane bioreactor for wastewater treatment.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-12},
doi = {10.1080/08927014.2022.2081805},
pmid = {35686374},
issn = {1029-2454},
abstract = {Membrane costs and biofouling limit applications of membrane bioreactors (MBRs) for wastewater treatment. Here, powdered activated carbon (PAC) utilization in the formation and performance of a self-forming dynamic membrane consisting of activated sludge and PAC during hybrid wastewater treatment process was studied. Short-term agitation helped (non)biological particles to quickly uniformly settle on mesh filter, forming more uniform PAC-containing dynamic membranes (PAC-DMs). PAC adsorbed adhesive materials, resulting in an increase in average floc size and DM permeability while decreasing biofouling. The most efficient PAC concentration was 4 g L-1 considering techno-economics, i.e. the highest effluent quality (turbidity of 19.89 NTU) and the lowest biofouling (transmembrane pressure rise of 2.89 mbar). Short-term performance of hybrid PAC-DM bioreactor (PAC-DMBR) showed stability in effluent quality improvement including 92%, 95%, 83%, 84% and 98% reductions in turbidity, chemical oxygen demand, total dissolved solids, total nitrogen, and total phosphorous, respectively. Accordingly, adopting hybrid PAC-DMBR has potential to alleviate biofouling and capital cost.},
}
@article {pmid35686192,
year = {2022},
author = {Qian, W and Li, X and Yang, M and Liu, C and Kong, Y and Li, Y and Wang, T and Zhang, Q},
title = {Relationship Between Antibiotic Resistance, Biofilm Formation, and Biofilm-Specific Resistance in Escherichia coli Isolates from Ningbo, China.},
journal = {Infection and drug resistance},
volume = {15},
number = {},
pages = {2865-2878},
doi = {10.2147/IDR.S363652},
pmid = {35686192},
issn = {1178-6973},
abstract = {Purpose: Several Escherichia coli pathotypes still constitute an important public health concern owing to its pathogenicity and antimicrobial resistance. Moreover, biofilm formation of E. coli can allow the strains to interfere with host and antimicrobial eradication, thus conferring additional resistance. The association between the formation of biofilm and antimicrobial resistance determinants has been extensively exploited; nevertheless, there is still no definite conclusion. The purpose of this study was to provide additional data to augment the present knowledge about the subject.<br><br>Methods: Antibiotic resistance/susceptibility profiles of 81 isolates from pediatric individuals in China between 2011 and 2014 against 20 antibiotics were assessed using the VITEK 2 system. Biofilm-forming capacities were evaluated using the crystal violet staining method, confocal laser scanning microscopy (CLSM), and field emission scanning electron microscopy. Biofilm compositions inside the biofilm formed by representative strains were assessed using CLSM. The effects of antibiotics on biofilms generated by E. coli strains of different biofilm-forming ability were examined using CLSM in combination with gatifloxacin. The relationships between antibiotic resistance, biofilm formation, and biofilm-specific resistance in E. coli isolates were investigated.<br><br>Results: The results showed that 23 isolates were classified as multidrug-resistant, and 57 isolates were classified as extensively drug-resistant (XDR). Among the 69 isolates with the ability to form biofilms, 46 isolates were stronger biofilm formers. Correlation analysis demonstrated that strain populations exhibiting more robust biofilm formation likely contained larger proportions of XDR isolates.<br><br>Conclusion: Together, our study implies that there was an association between biofilm-formation and resistance to several antibiotics for XDR-E. coli isolates, and would provide novel insights regarding the prevention and treatment against E. coli-related infections.},
}
@article {pmid35685939,
year = {2022},
author = {Tan, Y and Ma, S and Ding, T and Ludwig, R and Lee, J and Xu, J},
title = {Enhancing the Antibiofilm Activity of β-1,3-Glucanase-Functionalized Nanoparticles Loaded With Amphotericin B Against Candida albicans Biofilm.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {815091},
doi = {10.3389/fmicb.2022.815091},
pmid = {35685939},
issn = {1664-302X},
abstract = {Candida biofilm-related infections cause increased morbidity and mortality in patients with a reduced immune response. Traditional antifungal therapies have proven to be insufficient as the biofilm matrix acts as a perfusion barrier. Thus, novel methods are required to improve drug delivery and kill Candida within the biofilm. In this study, chitosan nanoparticles (CSNPs) loaded with Amphotericin B (AMB), which were functionalized with β-1,3-glucanase (Gls), were fabricated (CSNPs-AMB-Gls), and their antibiofilm activity against Candida albicans biofilm was evaluated in vitro. Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) were employed to examine biofilm architecture and cell viability. CSNPs-AMB-Gls inhibited planktonic cell growth and biofilm formation effectively and exhibited the highest efficacy on the removal of a mature biofilm than free AMB or CSNPs-AMB. The created nanoparticles (NPs) were found to penetrate the biofilm so as to directly interfere with the cells inside and disassemble the biofilm matrix. CSNPs-AMB-Gls could also eradicate biofilms from clinical isolates. These results suggest the potential applicability of CSNPs-AMB-Gls for the treatment of Candida biofilm-related infections.},
}
@article {pmid35684540,
year = {2022},
author = {Berkl, Z and Fekete-Kertész, I and Buda, K and Vaszita, E and Fenyvesi, É and Szente, L and Molnár, M},
title = {Effect of Cyclodextrins on the Biofilm Formation Capacity of Pseudomonas aeruginosa PAO1.},
journal = {Molecules (Basel, Switzerland)},
volume = {27},
number = {11},
pages = {},
doi = {10.3390/molecules27113603},
pmid = {35684540},
issn = {1420-3049},
support = {TKP2021-EGA-02//HUNGARIAN NATIONAL RESEARCH, DEVELOPMENT AND INNOVATION OFFICE/ ; K_17 Program (K_17 125093)//HUNGARIAN NATIONAL RESEARCH, DEVELOPMENT AND INNOVATION OFFICE/ ; },
abstract = {Quorum sensing (QS) is a population-density-dependent communication process of microorganisms to coordinate their activities by producing and detecting low-molecular-weight signal molecules. In pathogenic bacteria, the property controlled by QS is often related to infectivity, e.g., biofilm formation. Molecular encapsulation of the QS signals is an innovative method to prevent the signals binding to the receptors and to attenuate QS. Cyclodextrins (CDs) may form an inclusion complex with the signals, thus reducing the communication (quorum quenching, QQ). A systematic study was performed with α-, β-cyclodextrin, and their random methylated, quaternary amino and polymer derivatives to evaluate and compare their effects on the biofilm formation of Pseudomonas aeruginosa. To examine the concentration-, temperature- and time-dependency of the QQ effect, the CDs were applied at a 0.1-12.5 mM concentration range, and biofilm formation was studied after 6, 24, 48 and 72 h at 22 and 30 °C. According to the results, the QS mechanism was significantly inhibited; the size of the cavity, the structure of the substituents, as well as the monomeric or polymeric character together with the concentration of the CDs have been identified as key influencing factors of biofilm formation. Statistically determined effective concentration values demonstrated outstanding efficiency (higher than 80% inhibition) of α-CD and its random methylated and polymer derivatives both on the short and long term. In summary, the potential value of CDs as inhibitors of QS should be considered since the inhibition of biofilm formation could significantly impact human health and the environment.},
}
@article {pmid35684205,
year = {2022},
author = {Ghazal, TSA and Schelz, Z and Vidács, L and Szemerédi, N and Veres, K and Spengler, G and Hohmann, J},
title = {Antimicrobial, Multidrug Resistance Reversal and Biofilm Formation Inhibitory Effect of Origanum majorana Extracts, Essential Oil and Monoterpenes.},
journal = {Plants (Basel, Switzerland)},
volume = {11},
number = {11},
pages = {},
doi = {10.3390/plants11111432},
pmid = {35684205},
issn = {2223-7747},
support = {K135845//National Research, Development and Innovation Office/ ; },
abstract = {Origanum majorana L. is a widely used medicinal plant; its distilled oil and preparations are extensively utilised in the phytotherapy and food industries. The objective of this study is to evaluate the extracts and the essential oil (EO) of Origanum majorana L, and its monoterpenes for antimicrobial, bacterial multidrug resistance reversing, and biofilm formation inhibitory potency. The composition of EO and n-hexane extract was characterized by GC-MS. In the essential oil terpinen-4-ol (24.92%), trans-sabinene hydrate (25.18%), γ-terpinene (6.48%), cis-sabinene hydrate (5.44%), p-cymene (4.72%), sabinene (4.53%), α-terpineol (4.43%), and α-terpinene (3.00%) were found as the main constituents while trans-sabinene hydrate (1.43%), and terpinen-4-ol (0.19%) were detected in the n-hexane extract besides a series of hydrocarbons. The antibacterial activity of EO and terpinen-4-ol, α-terpinene, and linalool was also assessed against sensitive and drug-resistant S. aureus, and E. coli strains with MIC values of 0.125-0.250% and 30-61 µM, respectively. In the efflux pump (EP) inhibitory assay, made by the ethidium bromide accumulation method in E. coli ATCC 25922, and AG100 and S. aureus ATCC 25923, and MRSA ATCC 43300 strains, EO exhibited substantial activity, especially in the E. coli ATCC 25922 strain. Among the EO constituents, only sabinene was an EP inhibitor in sensitive Escherichia strain. In the case of S. aureus strains, EO and sabinene hydrate exhibited moderate potency on the drug-resistant phenotype. The antibiofilm effects of the samples were tested by crystal violet staining at sub-MIC concentration. γ-Terpinene, terpinen-4-ol, sabinene, sabinene hydrate and linalool were found to be effective inhibitors of biofilm formation (inhibition 36-86%) on E. coli ATCC 25922 and S. aureus MRSA ATCC 43300, while EO was ineffective on these strains. In contrast to this, biofilms formed by E. coli AG100 and S. aureus ATCC 25923 were significantly inhibited by the EO; however, it was not affected by any of the monoterpenes. This observation suggests that the antibiofilm effect might be altered by the synergism between the components of the essential oil.},
}
@article {pmid35684202,
year = {2022},
author = {Adeosun, IJ and Baloyi, IT and Cosa, S},
title = {Anti-Biofilm and Associated Anti-Virulence Activities of Selected Phytochemical Compounds against Klebsiella pneumoniae.},
journal = {Plants (Basel, Switzerland)},
volume = {11},
number = {11},
pages = {},
doi = {10.3390/plants11111429},
pmid = {35684202},
issn = {2223-7747},
support = {Self-Initiated Research//South African Medical Research Council/ ; },
abstract = {The ability of Klebsiella pneumoniae to form biofilm renders the pathogen recalcitrant to various antibiotics. The difficulty in managing K. pneumoniae related chronic infections is due to its biofilm-forming ability and associated virulence factors, necessitating the development of efficient strategies to control virulence factors. This study aimed at evaluating the inhibitory potential of selected phytochemical compounds on biofilm-associated virulence factors in K. pneumoniae, as well as authenticating their antibiofilm activity. Five phytochemical compounds (alpha-terpinene, camphene, fisetin, glycitein and phytol) were evaluated for their antibacterial and anti-biofilm-associated virulence factors such as exopolysaccharides, curli fibers, and hypermucoviscosity against carbapenem-resistant and extended-spectrum beta-lactamase-positive K. pneumoniae strains. The antibiofilm potential of these compounds was evaluated at initial cell attachment, microcolony formation and mature biofilm formation, then validated by in situ visualization using scanning electron microscopy (SEM). Exopolysaccharide surface topography was characterized using atomic force microscopy (AFM). The antibacterial activity of the compounds confirmed fisetin as the best anti-carbapenem-resistant K. pneumoniae, demonstrating a minimum inhibitory concentration (MIC) value of 0.0625 mg/mL. Phytol, glycitein and α-terpinene showed MIC values of 0.125 mg/mL for both strains. The assessment of the compounds for anti-virulence activity (exopolysaccharide reduction) revealed an up to 65.91% reduction in phytol and camphene. Atomic force microscopy detected marked differences between the topographies of untreated and treated (camphene and phytol) exopolysaccharides. Curli expression was inhibited at both 0.5 and 1.0 mg/mL by phytol, glycitein, fisetin and quercetin. The hypermucoviscosity was reduced by phytol, glycitein, and fisetin to the shortest mucoid string (1 mm) at 1 mg/mL. Phytol showed the highest antiadhesion activity against carbapenem-resistant and extended-spectrum beta-lactamase-positive K. pneumoniae (54.71% and 50.05%), respectively. Scanning electron microscopy correlated the in vitro findings, with phytol significantly altering the biofilm architecture. Phytol has antibiofilm and antivirulence potential against the highly virulent K. pneumoniae strains, revealing it as a potential lead compound for the management of K. pneumoniae-associated infections.},
}
@article {pmid35683049,
year = {2022},
author = {Petrović, M and Randjelović, M and Igić, M and Randjelović, M and Arsić Arsenijević, V and Mionić Ebersold, M and Otašević, S and Milošević, I},
title = {Poly(methyl methacrylate) with Oleic Acid as an Efficient Candida albicans Biofilm Repellent.},
journal = {Materials (Basel, Switzerland)},
volume = {15},
number = {11},
pages = {},
doi = {10.3390/ma15113750},
pmid = {35683049},
issn = {1996-1944},
support = {No. 2014.0040/Serbia/OP.//Swiss Government Excellence Scholarship/ ; },
abstract = {Poly(methyl methacrylate) (PMMA), widely used in dentistry, is unfortunately a suitable substrate for Candida (C.) albicans colonization and biofilm formation. The key step for biofilm formation is C. albicans ability to transit from yeast to hypha (filamentation). Since oleic acid (OA), a natural compound, prevents filamentation, we modified PMMA with OA aiming the antifungal PMMA_OA materials. Physico-chemical properties of the novel PMMA_OA composites obtained by incorporation of 3%, 6%, 9%, and 12% OA into PMMA were characterized by Fourier-transform infrared spectroscopy and water contact angle measurement. To test antifungal activity, PMMA_OA composites were incubated with C. albicans and the metabolic activity of both biofilm and planktonic cells was measured with a XTT test, 0 and 6 days after composites preparation. The effect of OA on C. albicans morphology was observed after 24 h and 48 h incubation in agar loaded with 0.0125% and 0.4% OA. The results show that increase of OA significantly decreased water contact angle. Metabolic activity of both biofilm and planktonic cells were significantly decreased in the both time points. Therefore, modification of PMMA with OA is a promising strategy to reduce C. albicans biofilm formation on denture.},
}
@article {pmid35682576,
year = {2022},
author = {Puhm, M and Hendrikson, J and Kivisaar, M and Teras, R},
title = {Pseudomonas putida Biofilm Depends on the vWFa-Domain of LapA in Peptides-Containing Growth Medium.},
journal = {International journal of molecular sciences},
volume = {23},
number = {11},
pages = {},
doi = {10.3390/ijms23115898},
pmid = {35682576},
issn = {1422-0067},
support = {PRG707//Estonian Research Council/ ; },
abstract = {The biofilm of Pseudomonas putida is complexly regulated by several intercellular and extracellular factors. The cell surface adhesin LapA of this bacterium is a central factor for the biofilm and, consequently, the regulation of lapA expression, for example, by Fis. It has been recently shown that peptides in growth media enhance the formation of P. putida biofilm, but not as a source of carbon and nitrogen. Moreover, the peptide-dependent biofilm appeared especially clearly in the fis-overexpression strain, which also has increased LapA. Therefore, we investigate here whether there is a relationship between LapA and peptide-dependent biofilm. The P. putida strains with inducible lapA expression and LapA without the vWFa domain, which is described as a domain similar to von Willebrand factor domain A, were constructed. Thereafter, the biofilm of these strains was assessed in growth media containing extracellular peptides in the shape of tryptone and without it. We show that the vWFa domain in LapA is necessary for biofilm enhancement by the extracellular peptides in the growth medium. The importance of vWFa in LapA was particularly evident for the fis-overexpression strain F15. The absence of the vWFa domain diminished the positive effect of Fis on the F15 biofilm.},
}
@article {pmid35681328,
year = {2022},
author = {Wang, L and Ju, X and Cong, Y and Lin, H and Wang, J},
title = {A Single Catalytic Endolysin Domain Plychap001: Characterization and Application to Control Vibrio parahaemolyticus and Its Biofilm Directly.},
journal = {Foods (Basel, Switzerland)},
volume = {11},
number = {11},
pages = {},
doi = {10.3390/foods11111578},
pmid = {35681328},
issn = {2304-8158},
support = {31870166//National Natural Science Foundation of China/ ; CARS-47//China Agriculture Research System/ ; },
abstract = {Endolysins are enzymes used by bacteriophages to cleave the host cell wall in the final stages of the lytic cycle. As such, they are considered promising antibacterial agents for controlling and combating multidrug-resistant (MDR) bacteria. However, the application of endolysins targeting Gram-negative bacteria is greatly hindered by the outer membrane on these bacteria. Lysqdvp001, an endolysin with modular structure, has been reported as one of the most efficient endolysins against the Gram-negative bacterium Vibrio parahaemolyticus. In this study, Plychap001, the truncated recombinant catalytic domain of Lysqdvp001, was demonstrated to exhibit a direct and efficient bactericidal activity against broad spectrum of V. parahaemolyticus strains. Plychap001 was shown to be highly stable and retain high bactericidal activity at high temperatures, over a wide pH range, and at high NaCl concentrations. Plychap001 also exhibited a synergistic lytic effect with EDTA. Additionally, Plychap001 was found to efficiently degrade and eliminate V. parahaemolyticus biofilms on polystyrene surfaces. Our study establishes Plychap001 as a promising method for controlling V. parahaemolyticus in the food industry.},
}
@article {pmid35678575,
year = {2022},
author = {Sharma, N and Das, A and Raja, P and Marathe, SA},
title = {The CRISPR-Cas System Differentially Regulates Surface-Attached and Pellicle Biofilm in Salmonella enterica Serovar Typhimurium.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0020222},
doi = {10.1128/spectrum.00202-22},
pmid = {35678575},
issn = {2165-0497},
abstract = {The CRISPR-Cas mediated regulation of biofilm by Salmonella enterica serovar Typhimurium was investigated by deleting CRISPR-Cas components ΔcrisprI, ΔcrisprII, ΔΔcrisprI crisprII, and Δcas op. We determined that the system positively regulates surface biofilm while inhibiting pellicle biofilm formation. Results of real-time PCR suggest that the flagellar (fliC, flgK) and curli (csgA) genes were repressed in knockout strains, causing reduced surface biofilm. The mutants displayed altered pellicle biofilm architecture. They exhibited bacterial multilayers and a denser extracellular matrix with enhanced cellulose and less curli, ergo weaker pellicles than those of the wild type. The cellulose secretion was more in the knockout strains due to the upregulation of bcsC, which is necessary for cellulose export. We hypothesized that the secreted cellulose quickly integrates into the pellicle, leading to enhanced pellicular cellulose in the knockout strains. We determined that crp is upregulated in the knockout strains, thereby inhibiting the expression of csgD and, hence, also of csgA and bcsA. The conflicting upregulation of bcsC, the last gene of the bcsABZC operon, could be caused by independent regulation by the CRISPR-Cas system owing to a partial match between the CRISPR spacers and bcsC gene. The cAMP-regulated protein (CRP)-mediated regulation of the flagellar genes in the knockout strains was probably circumvented through the regulation of yddx governing the availability of the sigma factor σ28 that further regulates class 3 flagellar genes (fliC, fljB, and flgK). Additionally, the variations in the lipopolysaccharide (LPS) profile and expression of LPS-related genes (rfaC, rfbG, and rfbI) in knockout strains could also contribute to the altered pellicle architecture. Collectively, we establish that the CRISPR-Cas system differentially regulates the formation of surface-attached and pellicle biofilm. IMPORTANCE In addition to being implicated in bacterial immunity and genome editing, the CRISPR-Cas system has recently been demonstrated to regulate endogenous gene expression and biofilm formation. While the function of individual cas genes in controlling Salmonella biofilm has been explored, the regulatory role of CRISPR arrays in biofilm is less studied. Moreover, studies have focused on the effects of the CRISPR-Cas system on surface-associated biofilms, and comprehensive studies on the impact of the system on pellicle biofilm remain an unexplored niche. We demonstrate that the CRISPR array and cas genes modulate the expression of various biofilm genes in Salmonella, whereby surface and pellicle biofilm formation is distinctively regulated.},
}
@article {pmid35677656,
year = {2022},
author = {Su, FJ and Periyasamy, T and Chen, MM},
title = {Comparative Transcriptomic Immune Responses of Mullet (Mugil cephalus) Infected by Planktonic and Biofilm Lactococcus Garvieae.},
journal = {Frontiers in cellular and infection microbiology},
volume = {12},
number = {},
pages = {887921},
doi = {10.3389/fcimb.2022.887921},
pmid = {35677656},
issn = {2235-2988},
abstract = {Lactococcus garvieae is an important pathogen of fish, associated with high rates of mortality and infection recurrence in summer or stressful conditions. Chronic infection and disease recurrence have also been reported to be associated with biofilms. However, the impact of biofilm and planktonic bacterial infection on fish immune responses remains unclear. In this study, de novo sequencing was used to compare differences of the spleen transcriptome in planktonic- and biofilm-infected mullets. Among the 181,024 unigenes obtained, 3,392 unigenes were associated with immune response genes. Comparative analysis of the gene expression between infection with the L. garvieae planktonic type and biofilm type identified a total of 3,120 and 3,489 differentially expressed genes in response to planktonic and biofilm infection, respectively, of which 1,366 and 1,458 genes were upregulated, and 1,754 and 1,458 genes were downregulated, respectively. Gene ontology enrichment analysis of immune genes identified genes involved in the complement system, toll-like receptor signaling, and antigen processing, which were further verified by qPCR. Additionally, genes encoding TLR2, IL-1β, TNF-α, C7, and MHC class II peptides were downregulated in response to biofilm infection. Importantly, the results show that biofilm infection induces a different immune pathway response compared with planktonic bacterial infection and, furthermore, illustrates that the prevention of biofilm formation may be a necessary and new strategy for controlling bacterial infection in aquaculture.},
}
@article {pmid35676766,
year = {2022},
author = {Dong, F and Liu, S and Zhang, D and Zhang, J and Wang, X},
title = {Matrix-producing cells formed 'Van Gogh bundles' facilitate Bacillus subtilis biofilm self-healing.},
journal = {Environmental microbiology reports},
volume = {},
number = {},
pages = {},
doi = {10.1111/1758-2229.13099},
pmid = {35676766},
issn = {1758-2229},
support = {11620101001//National Natural Science Foundation of China/ ; 11772047//National Natural Science Foundation of China/ ; 11972074//National Natural Science Foundation of China/ ; },
abstract = {Biofilms grow and expand through cell differentiation into various phenotypes, which have different functions and cooperate with each other. In our experiments, we find that biofilms can heal after damaged, and we also find there is a special structure near the cut, which is called the 'Van Gogh bundles' by Jordi et al. because of its resemblance to Van Gogh's famous painting 'The Starry Night'. Here, we study the 'Van Gogh bundles' structure evolution near the cut area, and how 'Van Gogh bundles' structure facilitates the cut healing by observing microscopic images of bacterial colonies growing from wild-type and mutant strains. We find that the amount of matrix-producing cells contributes to the 'Van Gogh bundles' structure, such as curvature. Through the comparison of curvatures of 'Van Gogh bundles' and the rate of the cut healing, we find that the smaller the curvature, the faster healing rate. To better explain the above experiment observations, we establish an individual-based model and simulate the formation and growth of 'Van Gogh bundles' along the cut by giving rules for an individual cell like cell growth, division and turning rules, and also 'Van Gogh bundles' fold division rule.},
}
@article {pmid35676463,
year = {2022},
author = {Zarei, M and Bahrami, S and Liljebjelke, K},
title = {Biofilm formation of Salmonella enterica serovar Enteritidis cocultured with Acanthamoeba castellanii responds to nutrient availability.},
journal = {International microbiology : the official journal of the Spanish Society for Microbiology},
volume = {},
number = {},
pages = {},
pmid = {35676463},
issn = {1618-1905},
abstract = {Acanthamoeba spp. and Salmonella share common habitats, and their interaction may influence the biofilm-forming ability of Salmonella. In this study, biofilm formation of Salmonella enterica serovar Enteritidis cocultured with Acanthamoeba castellanii was examined in nutrient-rich and nutrient-deficient media. Furthermore, transcript copy number of biofilm-related genes in the biofilm cells of S. Enteritidis in monoculture was compared to those in coculture with A. castellanii. Results demonstrated that the presence of A. castellanii in the culture media activates the genes involved in the biofilm formation of S. Enteritidis, regardless of the nutrient availability. However, biofilm formation of S. Enteritidis cocultured with A. castellanii was not consistent with the transcript copy number results. In nutrient-rich medium, the number of Salmonella biofilm cells and the contents of the three main components of the biofilms including eDNA, protein, and carbohydrates were higher in the presence of A. castellanii compared to monocultures. However, in nutrient-deficient medium, the number of biofilm cells, and the amount of biofilm components in coculture conditions were less than the monocultures. These results indicate that despite activation of relevant genes in both nutrient-rich and nutrient-deficient media, biofilm formation of S. Enteritidis cocultured with A. castellanii responds to nutrient availability.},
}
@article {pmid35676412,
year = {2022},
author = {Aziz, SAAA and Mahmoud, R and Mohamed, MBED},
title = {Control of biofilm-producing Pseudomonas aeruginosa isolated from dairy farm using Virokill silver nano-based disinfectant as an alternative approach.},
journal = {Scientific reports},
volume = {12},
number = {1},
pages = {9452},
pmid = {35676412},
issn = {2045-2322},
abstract = {Pseudomonas aeruginosa (P. aeruginosa) is an important opportunistic pathogen that is responsible for many clinical infections in both animals and humans. This study aimed to detect the prevalence of P. aeruginosa in dairy farm's that possess a great importance to dairy industry where it shares in milk spoilage. Evaluation of the efficacy of commonly used disinfectants to control the pathogen in dairy environment and finding a way to overcome high resistance to the used agents. Samples (n = 250) were collected from different environmental components, milk, and milkers' hands. Pathogens were isolated, biofilm was detected and their sensitivity against two commonly used disinfectants and against silver nanoparticles and Virokill AgNPs at different concentrations and contact times were tested. The pathogen significantly prevailed in milk samples (70.0%, P < 0.001). 50 out 74 isolates were biofilm-forming that was significantly obtained from environment (71.8%, P < 0.001). P. aeruginosa showed variable degree of resistance to tested disinfectants but it was significantly sensitive to Virokill AgNPs (200/1000) mg/l at exposure time 24 h (P < 0.001). It was concluded that using Virokill AgNPs in regular sanitation and disinfection of dairy farms, this helps the control of P. aeruginosa subsequently increasing milk quality and improving dairy industry and protecting human health.},
}
@article {pmid35674583,
year = {2022},
author = {Borges, EL and Amorim, GL and Miranda, MB and Martins, FDS and Guedes, ACM and Sampaio, KH and Spira, JAO and Barcelos, LDS},
title = {Biofilm model on mice skin wounds.},
journal = {Acta cirurgica brasileira},
volume = {37},
number = {3},
pages = {e370306},
doi = {10.1590/acb370306},
pmid = {35674583},
issn = {1678-2674},
abstract = {PURPOSE: To evaluate a biofilm model of Pseudomonas aeruginosa in excisional cutaneous wound in mice.<br><br>METHODS: Preclinical, translational study conducted with 64 C57BL/6 mice randomly assigned to control and intervention groups. Evaluation was on days D0, D3, D5, D7 and D10 of wound making. The profile of biofilm formation and induction was evaluated using wound closure kinetics, quantitative culture, and evaluation of wounds using transmission electron microscopy (TEM). Clinical evaluation was performed by liver tissue culture, weight variation, and quantification of leukocytes in peripheral blood. Analyses were performed with GraphPad Prism software.<br><br>RESULTS: Bacterial load for induction of infection with P. aeruginosa and survival of animals was 104 UFC·mL-1. In D5 (p < 0.0001) and D7 (p < 0.01), animals in the intervention group showed a delay in the healing process and had their wounds covered by necrotic tissue until D10. Statistical differences were observed in wound cultures and weight at D5 and D7 (p < 0.01). Liver cultures and leukocyte quantification showed no statistical differences. No bacteria in planktonic or biofilm form were identified by TEM.<br><br>CONCLUSIONS: The findings raise questions about the understanding of the ease of formation and high occurrence of biofilm in chronic wounds.},
}
@article {pmid35673888,
year = {2022},
author = {Pan, M and Lu, C and Zheng, M and Zhou, W and Song, F and Chen, W and Yao, F and Liu, D and Cai, J},
title = {Unnatural Amino-Acid-Based Star-Shaped Poly(l-Ornithine)s as Emerging Long-Term and Biofilm-Disrupting Antimicrobial Peptides to Treat Pseudomonas aeruginosa-Infected Burn Wounds.},
journal = {Advanced healthcare materials},
volume = {11},
number = {11},
pages = {e2200944},
doi = {10.1002/adhm.202200944},
pmid = {35673888},
issn = {2192-2659},
}
@article {pmid35672892,
year = {2022},
author = {Du, Z and Qiao, L and Yang, W and Chen, Y and Zhang, Y and Wu, W and Li, J and Wang, W and Cui, L and Chen, S},
title = {A multicenter, double-blind, placebo-controlled parallel study to evaluate the role of Yinhua Miyanling tablets in the prevention of bacterial biofilm formation on ureteral stents: a randomised trial.},
journal = {Annals of palliative medicine},
volume = {11},
number = {5},
pages = {1752-1761},
doi = {10.21037/apm-22-324},
pmid = {35672892},
issn = {2224-5839},
abstract = {BACKGROUND: Yinhua Miyanling tablet (YMT) not only has the functions of clearing away heat and toxin, dredging drenching and diuresis, but also has antibacterial activity. The formation of bacterial biofilm in ureteral stent and its related infection have plagued the clinic. Antibacterial traditional Chinese medicine is a potential method.<br><br>METHODS: This multicenter, randomized, double-blind, placebo-controlled study was designed to enroll patients who underwent ureteroscopic lithotripsy associated with indwelling ureteral stents at six centers between March 2019 and June 2020. The eligible patients were randomly assigned to the experimental group to take YMT 2 g qid orally or the control group to take dummy YMT 2 g qid orally from the first day after the operation according to a random number table. The unused drugs were recalled 14±3 days after the operation and record the body temperature. Relevant laboratory tests (urinalysis and urine culture) were performed before extubation. The ureteral stent was removed. The specimen was collected for scanning electron microscopy (SEM). Biofilm formation, USSQ scores, postoperative infectious complications, stone formation, and adverse drug reactions were compared between the two groups.<br><br>RESULTS: Of the 211 patients enrolled, 165 were included in the per-protocol set (PPS), including 86 in the control group and 79 in the experimental group. No significant difference was found between the two groups in baseline parameters (P>0.05). The prevalence of biofilm formation in the control group (47%) was significantly higher than that in the experimental group (22.7%, P=0.001). There was no significant difference in total USSQ score and domain score between the two groups (all P>0.05). There were more patients with symptomatic urinary tract infection (UTI) in the control group (12.9%) than in the experimental group (2.6%, P=0.017). The incidence of other complications did not show a significant difference between the two groups (all P>0.05). The incidence of stone formation on the ureteral stent surface and adverse drug reactions did not show a significant difference between the two groups (all P>0.05).<br><br>CONCLUSIONS: YMT is helpful to reduce the formation of bacterial biofilms on ureteral stents and the incidence of symptomatic UTIs related to ureteral stenting after surgery for ureteral calculi.<br><br>TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2000041399.},
}
@article {pmid35671532,
year = {2022},
author = {Teschler, JK and Nadell, CD and Drescher, K and Yildiz, FH},
title = {Mechanisms Underlying Vibrio cholerae Biofilm Formation and Dispersion.},
journal = {Annual review of microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1146/annurev-micro-111021-053553},
pmid = {35671532},
issn = {1545-3251},
abstract = {Biofilms are a widely observed growth mode in which microbial communities are spatially structured and embedded in a polymeric extracellular matrix. Here, we focus on the model bacterium Vibrio cholerae and summarize the current understanding of biofilm formation, including initial attachment, matrix components, community dynamics, social interactions, molecular regulation, and dispersal. The regulatory network that orchestrates the decision to form and disperse from biofilms coordinates various environmental inputs. These cues are integrated by several transcription factors, regulatory RNAs, and second-messenger molecules, including bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP). Through complex mechanisms, V. cholerae weighs the energetic cost of forming biofilms against the benefits of protection and social interaction that biofilms provide. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.},
}
@article {pmid35671527,
year = {2022},
author = {Hill, DL and Castiaux, A and Pensler, E and Knue, J and Attar, PS and Siddiqi, A},
title = {A Novel Activated Zinc Solution with Improved Efficacy Against Pseudomonas and MRSA Biofilm Compared to Chlorhexidine and Povidone-Iodine.},
journal = {Surgical technology international},
volume = {41},
number = {},
pages = {},
pmid = {35671527},
issn = {1090-3941},
abstract = {INTRODUCTION: The search for the optimal agent for infection eradication in periprosthetic joint infection (PJI) remains challenging as there are limited efficacious and safe options. The ideal solution should have significant bactericidal and anti-biofilm activity to be able to eradicate infection with the preservation of prosthetic components. Therefore, the purpose of this study was to 1) investigate the anti-biofilm efficacy of a novel activated zinc solution against Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) biofilm in vitro and 2) compare its efficacy against two leading commercially available antimicrobial irrigants (CHG and 0.35% povidone-iodine [PI]).<br><br>MATERIALS AND METHODS: A modified Robbins device (MRD) was utilized to replicate Pseudomonas aeruginosa and MRSA biofilms. The primary outcome was to determine bacterial reduction after two hours of biofilm exposure to an activated zinc solution, CHG, and PI, and compare to untreated controls.<br><br>RESULTS: Against Pseudomonas biofilm, activated zinc demonstrated a 4.5-log (99.996%) reduction, chlorhexidine demonstrated a 0.9-log (87.4%) reduction (p<0.001), and PI demonstrated a 0.8-log (83.1%) reduction (p<0.001). After two hours of exposure, activated zinc had undetectable MRSA with a 7.08-log (100%) reduction, chlorhexidine had a 1.9-log (98.7%) reduction (p<0.01), and PI had a 3.2-log (99.9%) reduction (p<0.01).<br><br>CONCLUSIONS: Our novel activated zinc compound demonstrated a 99.996% reduction in Pseudomonas biofilm and a 100% reduction in MRSA biofilm. This novel solution may provide a significant tool in the arsenal to treat and/or prevent PJI and other wound infections. Future in vivo studies are warranted to demonstrate clinical utility, efficacy, and safety.},
}
@article {pmid35671186,
year = {2022},
author = {Wang, L and Tao, Z and Lu, B},
title = {Biofilm formation and invasive ability contribute to CC17 serotype III group B Streptococcus virulence.},
journal = {Chinese medical journal},
volume = {135},
number = {7},
pages = {869-871},
pmid = {35671186},
issn = {2542-5641},
}
@article {pmid35670600,
year = {2022},
author = {Jiang, Y and Liang, C and Zhao, W and Chen, T and Yu, B and Hou, A and Zhu, J and Zhang, T and Liu, Q and Ying, H and Liu, D and Sun, W and Chen, Y},
title = {Cell Cycle Progression Influences Biofilm Formation in Saccharomyces cerevisiae 1308.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0276521},
doi = {10.1128/spectrum.02765-21},
pmid = {35670600},
issn = {2165-0497},
abstract = {Biofilm-immobilized continuous fermentation is a novel fermentation strategy that has been utilized in ethanol fermentation. Continuous fermentation contributes to the self-proliferation of Saccharomyces cerevisiae biofilms. Previously, we successfully described the cell cycle differences between biofilm-immobilized fermentation and calcium alginate-immobilized fermentation. In the present study, we investigated the relationship between biofilm formation and the cell cycle. We knocked down CLN3, SIC1, and ACE2 and found that Δcln3 and Δsic1 exhibited a predominance of G2/M phase cells, increased biofilm formation, and significantly increased extracellular polysaccharide formation and expression of genes in the FLO gene family during immobilisation fermentation. Δace2 exhibited a contrasting performance. These findings suggest that the increase in the proportion of cells in the G2/M phase of the cell cycle facilitates biofilm formation and that the cell cycle influences biofilm formation by regulating cell adhesion and polysaccharide formation. This opens new avenues for basic research and may also help to provide new ideas for biofilm prevention and optimization. IMPORTANCE Immobilised fermentation can be achieved using biofilm resistance, resulting in improved fermentation efficiency and yield. The link between the cell cycle and biofilms deserves further study since reports are lacking in this area. This study showed that the ability of Saccharomyces cerevisiae to produce biofilm differed when cell cycle progression was altered. Further studies suggested that cell cycle regulatory genes influenced biofilm formation by regulating cell adhesion and polysaccharide formation. Findings related to cell cycle regulation of biofilm formation set the stage for biofilm in Saccharomyces cerevisiae and provide a theoretical basis for the development of a new method to improve biofilm-based industrial fermentation.},
}
@article {pmid35669826,
year = {2022},
author = {Nabizadeh Nodehi, R and Golpayegani, A and Douraghi, M and Alimohammadi, M and Rezaei, F},
title = {Novel application of in vitro disinfection for modeling the biofilm formation inhibition, antimicrobial susceptibility and antibiotic resistance of Pseudomonas aeruginosa: a study of free and combined chlorine compounds.},
journal = {Journal of environmental health science &amp; engineering},
volume = {20},
number = {1},
pages = {167-180},
doi = {10.1007/s40201-021-00764-0},
pmid = {35669826},
issn = {2052-336X},
abstract = {Biofilm formation and antibiotic resistance are the most important ways in which water bacteria such as Pseudomonas aeruginosa are protected against antibacterial agents. The aim of this study was to develop a rapid and cost-effective laboratory method for modeling and optimizing chlorine disinfection conditions. Critical factors (disinfection type, concentration, contact time and pH) were tested on bactericidal effect, inhibition of biofilm formation (IBF) and antibiotic susceptibility (AS) of P. aeruginosa. The central composite face-centered (CCF) design was applied to model the effect of disinfection process on the IBF and AS. The results showed that the IBF response was more affected by the strain type of P. aeruginosa and the type of disinfectant, which may be due to previous species growth conditions of the standard strain and greater durability of CAT in water. Optimization of factors affecting disinfection had a significant effect on the planktonic form, but was not effective in removing the biofilm of P. aeruginosa. Furthermore, the concentration of NaOCl and CAT was more effective than pH on planktonic and biofilm cells inactivation. The model of AS was weaker than other models due to limited contact time and use of high concentrations of disinfectant. The use of chlorine compounds based on the recommended levels in water does not prevent the formation of P. aeruginosa biofilm. According to the optimization findings, although increasing the contact time and concentration of the disinfectant increases the bactericidal effect of chlorine, it can also increase the resistance of P. aeruginosa to some antibiotics.},
}
@article {pmid35668859,
year = {2022},
author = {Amankwah, S and Adisu, M and Gorems, K and Abdella, K and Kassa, T},
title = {Assessment of Phage-Mediated Inhibition and Removal of Multidrug-Resistant Pseudomonas aeruginosa Biofilm on Medical Implants.},
journal = {Infection and drug resistance},
volume = {15},
number = {},
pages = {2797-2811},
doi = {10.2147/IDR.S367460},
pmid = {35668859},
issn = {1178-6973},
abstract = {Purpose: Despite the growing interest in bacteriophage (phage) usage for the prevention, control, and removal of bacterial biofilms, few scientific data exist on phage applications on medical implant surfaces, while none exists on multiple implants. In this study, we aimed to isolate, biophysically characterize and assess phages as potential antibiofilm agents to inhibit and remove multidrug-resistant (MDR) Pseudomonas aeruginosa biofilm on catheter and endotracheal tube surfaces.<br><br>Methods: The well-identified stored clinical isolates (n = 7) of MDR P. aeruginosa were obtained from Jimma Medical Center. Specific phages were isolated and characterized based on standard protocols. The phages were tested for their antibiofilm effects in preventing colonization and removing preformed biofilms of MDR P. aeruginosa, following phage coating and treatment of catheter and endotracheal tube segments.<br><br>Results: Two P. aeruginosa-specific phages (ΦJHS-PA1139 and ΦSMK-PA1139) were isolated from JMC compound sewage sources. The phages were biophysically characterized as being thermally stable up to 40°C and viable between pH 4.0 and 11.0. The two phages tested against clinical MDR strains of P. aeruginosa showed broad host ranges but not on other tested bacterial species. Both phages reduced MDR bacterial biofilms during the screening step. The phage-coated segments showed 1.2 log10 up to 3.2 log10 inhibition relative to non-coated segments following 6 h coating of segments prior to microbial load exposure. In both phages, 6 h treatment of the segments with 106 PFU/mL yielded 1.0 log10 up to 1.6 log10 reductions for ΦJHS and 1.6 log10 up to 2.4 log10 reductions for ΦSMK.<br><br>Conclusion: Our results suggest that phages have great potential to serve the dual purpose as surface coating agents for preventing MDR bacterial colonization in medical implants and as biofilm removal agents in implant-associated infections.},
}
@article {pmid35668756,
year = {2022},
author = {Abdelraheem, WM and Refaie, MMM and Yousef, RKM and Abd El Fatah, AS and Mousa, YM and Rashwan, R},
title = {Assessment of Antibacterial and Anti-biofilm Effects of Vitamin C Against Pseudomonas aeruginosa Clinical Isolates.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {847449},
doi = {10.3389/fmicb.2022.847449},
pmid = {35668756},
issn = {1664-302X},
abstract = {There is a persistent need to look for alternative therapeutic modalities to help control the pandemic of antimicrobial resistance. Assessment of antibacterial and anti-biofilm effects of vitamin C (ascorbic acid) was the aim of the current study. The micro-dilution method determined the minimal inhibitory concentration (MIC) of ascorbic acid or antibiotics alone and in combinations against Pseudomonas aeruginosa (P. aeruginosa) clinical isolates. The micro-titer plate method monitored the effect of ascorbic acid on the biofilm-producing isolates of P. aeruginosa. The effect of ascorbic acid on the differential expression of different antibiotic-resistant genes and biofilm encoding genes of P. aeruginosa isolates were also tested using real-time polymerase chain reaction (PCR). For in vivo assessment of the antibacterial effects of ascorbic acid alone or combined with an antibiotic, rats were infected with P. aeruginosa clinical isolate followed by different treatment regimens. MICs of ascorbic acid among P. aeruginosa isolates were in the range of 156.2-1,250 μg/ml, while MIC50 and MIC90 were 312.5 and 625 μg/ml, respectively. At sub-inhibitory concentrations (19.5-312.5 μg/ml), ascorbic acid had 100% biofilm inhibitory effect. Furthermore, ascorbic acid-treated bacteria showed downregulation of genes underpinning biofilm formation and antibiotic resistance. In vivo assessment of vitamin C and ceftazidime in rats showed that administration of both at a lower dose for treatment of pseudomonas infection in rats had a synergistic and more powerful effect. Vitamin C shows excellent in vitro results as an antibacterial and anti-biofilm agent. Vitamin C should be routinely prescribed with antibiotics to treat bacterial infections in the clinical setting.},
}
@article {pmid35668112,
year = {2022},
author = {Berlanga-Clavero, MV and Molina-Santiago, C and Caraballo-Rodríguez, AM and Petras, D and Díaz-Martínez, L and Pérez-García, A and de Vicente, A and Carrión, VJ and Dorrestein, PC and Romero, D},
title = {Bacillus subtilis biofilm matrix components target seed oil bodies to promote growth and anti-fungal resistance in melon.},
journal = {Nature microbiology},
volume = {},
number = {},
pages = {},
pmid = {35668112},
issn = {2058-5276},
support = {PE 2600/1//Deutsche Forschungsgemeinschaft (German Research Foundation)/ ; GBMF7622//Gordon and Betty Moore Foundation (Gordon E. and Betty I. Moore Foundation)/ ; BacBio 637971//EC | EU Framework Programme for Research and Innovation H2020 | H2020 Priority Excellent Science | H2020 European Research Council (H2020 Excellent Science - European Research Council)/ ; P20_00479//Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía (Ministry of Economy, Innovation, Science and Employment, Government of Andalucia)/ ; UMA18-FEDERJA-055//Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía (Ministry of Economy, Innovation, Science and Employment, Government of Andalucia)/ ; AGL2016-78662-R//Ministerio de Economía y Competitividad (Ministry of Economy and Competitiveness)/ ; },
abstract = {Beneficial microorganisms are used to stimulate the germination of seeds; however, their growth-promoting mechanisms remain largely unexplored. Bacillus subtilis is commonly found in association with different plant organs, providing protection against pathogens or stimulating plant growth. We report that application of B. subtilis to melon seeds results in genetic and physiological responses in seeds that alter the metabolic and developmental status in 5-d and 1-month-old plants upon germination. We analysed mutants in different components of the extracellular matrix of B. subtilis biofilms in interaction with seeds and found cooperation in bacterial colonization of seed storage tissues and growth promotion. Combining confocal microscopy with fluorogenic probes, we found that two specific components of the extracellular matrix, amyloid protein TasA and fengycin, differentially increased the concentrations of reactive oxygen species inside seeds. Further, using electron and fluorescence microscopy and metabolomics, we showed that both TasA and fengycin targeted the oil bodies in the seed endosperm, resulting in specific changes in lipid metabolism and accumulation of glutathione-related molecules. In turn, this results in two different plant growth developmental programmes: TasA and fengycin stimulate the development of radicles, and fengycin alone stimulate the growth of adult plants and resistance in the phylloplane to the fungus Botrytis cinerea. Understanding mechanisms of bacterial growth promotion will enable the design of bespoke growth promotion strains.},
}
@article {pmid35666375,
year = {2022},
author = {Lima, NG and Monteiro, RM and Torres, CP and de Souza-Gabriel, AE and Watanabe, E and Borsatto, MC},
title = {Influence of antimicrobial photodynamic therapy with different pre-irradiation times on children's dental biofilm: randomized clinical trial.},
journal = {European archives of paediatric dentistry : official journal of the European Academy of Paediatric Dentistry},
volume = {},
number = {},
pages = {},
pmid = {35666375},
issn = {1996-9805},
abstract = {PURPOSE: Photodynamic therapy (PDT) is effective in reducing pathogenic microorganisms in the oral cavity and in preventing dental diseases. This study evaluated the pre-irradiation time using PDT (diode laser associated with 0.01% methylene blue) to decrease the number of microorganisms in the visible plaque in permanent teeth.<br><br>METHODS: This randomized clinical trial included 108 homologous lower permanent first molars (36 and 46) with biofilm from 54 children aged six to 12 years. PDT was performed (0.01% methylene blue photosensitizer/therapeutic laser-InGaAIP), according to the following protocols: Group 1, biofilm collection of the distal area of the lingual surface of 36 µm before PDT; group 2, mesial area of the lingual surface of 36 µm 1 min after PDT; group 3, area of the lingual surface of 46 µm before PDT; and group 4, mesial area of the lingual surface of 46 µm 5 min after PDT.<br><br>RESULTS: After statistical analysis, significant differences were observed between the groups (p = 0.000). In groups 2 and 4, the number of bacteria tended to decrease, with a more evident bacterial reduction in group 4.<br><br>CONCLUSIONS: Pre-irradiation reduced the number of colony-forming units of mature bacterial biofilms in vivo. A time of 5 min resulted in a greater reduction in the number of colony-forming units.<br><br>CLINICAL TRIAL REGISTRATION: ReBEC Identifier: RBR-6bqfp3; Date of Register: March 2nd, 2020. Retrospectively Registered.},
}
@article {pmid35663481,
year = {2022},
author = {Frühauf, HM and Stöckl, M and Holtmann, D},
title = {R-based method for quantitative analysis of biofilm thickness by using confocal laser scanning microscopy.},
journal = {Engineering in life sciences},
volume = {22},
number = {6},
pages = {464-470},
doi = {10.1002/elsc.202200008},
pmid = {35663481},
issn = {1618-0240},
abstract = {Microscopy is mostly the method of choice to analyse biofilms. Due to the high local heterogeneity of biofilms, single and punctual analyses only give an incomplete insight into the local distribution of biofilms. In order to retrieve statistically significant results a quantitative method for biofilm thickness measurements was developed based on confocal laser scanning microscopy and the programming language R. The R-script allows the analysis of large image volumes with little hands-on work and outputs statistical information on homogeneity of surface coverage and overall biofilm thickness. The applicability of the script was shown in microbial fuel cell experiments. It was found that Geobacter sulfurreducens responds differently to poised anodes of different material so that the optimum potential for MFC on poised ITO anodes had to be identified with respect to maximum current density, biofilm thickness and MFC start-up time. Thereby, a positive correlation between current density and biofilm thickness was found, but with no direct link to the applied potential. The optimum potential turned out to be +0.1 V versus SHE. The script proved to be a valuable stand-alone tool to quantify biofilm thickness in a statistically valid manner, which is required in many studies.},
}
@article {pmid35662380,
year = {2022},
author = {Li, J and McLaughlin, RW and Liu, Y and Zhou, J and Hu, X and Wan, X and Xie, H and Hao, Y and Zheng, J},
title = {Biofilm formation, antimicrobial assay, and toxin-genotypes of Clostridium perfringens type C isolates cultured from a neonatal Yangtze finless porpoise.},
journal = {Archives of microbiology},
volume = {204},
number = {7},
pages = {361},
pmid = {35662380},
issn = {1432-072X},
support = {31870372//National Natural Science Foundation of China/ ; ZSSD-004//the Bureau of Science &amp; Technology for Development, Chinese Academy of Sciences/ ; 2020M682530//Postdoctoral Research Foundation of China/ ; },
abstract = {This is a culture-dependent study with the objective of pure culturing and characterizing pathogenic bacteria from the blowhole, lung, stomach and fecal samples of a neonatal crucially endangered Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis) that died 27 days after birth. Bacteria were inoculated using a swab onto blood and MacConkey agar plates and representative isolates were identified through 16S rRNA gene sequence analysis. A total of three Clostridium perfringens type C strains from the fecal samples were isolated. Toxin genes, including cpa, cpb and cpb2, were detected by PCR amplification, whereas the etx, iap and cpe genes were not detected. Biofilm formation of the three strains was then examined. Only one strain was capable of biofilm formation. In addition, isolates showed strong resistance against the antibiotics amikacin (3/3), erythromycin (1/3), gentamicin (3/3), streptomycin (3/3), and trimethoprim (3/3), while sensitivity to ampicillin (3/3), bacitracin (3/3), erythromycin (2/3), penicillin G (3/3), and tetracycline (3/3). The results suggested C. perfringens type C could have contributed to the death of this neonatal porpoise.},
}
@article {pmid35661475,
year = {2022},
author = {},
title = {Physical, mechanical and anti-biofilm formation properties of CAD-CAM milled or 3D printed denture base resins: In Vitro analysis.},
journal = {Journal of prosthodontics : official journal of the American College of Prosthodontists},
volume = {},
number = {},
pages = {},
doi = {10.1111/jopr.13554},
pmid = {35661475},
issn = {1532-849X},
abstract = {PURPOSE: To investigate surface characteristics (roughness and contact angle), anti-biofilm formation, and mechanical properties (mini-flexural strength) of computer-aided design and computer-aided manufacturing (CAD-CAM) PMMA polymer, and three-dimensional (3D) printed resin for denture base fabrication compared with conventional heat polymerized denture base resins.<br><br>MATERIALS AND METHODS: A total of 60 discs and 40 rectangular specimens were fabricated from one CAD-CAM (AvaDent), one 3D printed (Cosmos Denture), and two conventional heat polymerized (Lucitone 199 and VipiWave) materials for denture base fabrication. Roughness was determined by Ra value; the contact angle was measured by the sessile drop method; the biofilm formation inhibition behavior was analyzed through C. albicans adhesion, while mini-flexural strength test was done using a three-point bending test. The data were analyzed using descriptive and analytical statistics (α = 0.05).<br><br>RESULTS: The CAD-CAM PMMA group showed the lowest C. albicans adhesion (log CFU/mL: 3.74 ±0.57) and highest mini-flexural strength mean (114.96 ±16.23 MPa). 3D printed specimens presented the highest surface roughness (Ra: 0.317 ±0.151 μm) and lowest mini-flexural strength values (57.23 ±9.07 MPa). However, there was no statistical difference between CAD-CAM PMMA and conventional groups for roughness, contact angle, and mini-flexural strength.<br><br>CONCLUSIONS: CAD-CAM milled materials present surface and mechanical properties similar to conventional resins and show improved behavior preventing C. albicans adhesion. Nevertheless, 3D printed resins present decreased mini-flexural strength. This article is protected by copyright. All rights reserved.},
}
@article {pmid35661216,
year = {2022},
author = {Priya, A and Pandian, SK},
title = {Biofilm and hyphal inhibitory synergistic effects of phytoactives piperine and cinnamaldehyde against Candida albicans.},
journal = {Medical mycology},
volume = {},
number = {},
pages = {},
doi = {10.1093/mmy/myac039},
pmid = {35661216},
issn = {1460-2709},
abstract = {Oral candidiasis, the most common mycotic infection of the human oral cavity is non-life-threatening yet if untreated may advance as systemic infections. Ability of Candida albicans to adapt sessile lifestyle imparts resistance to drugs and host immunity. Consequently, due to limited effectiveness of conventional antifungal treatment, novel therapeutic strategies are required. In the present study, synergistic interaction of phytochemicals, piperine and cinnamaldehyde against the biofilm and hyphal of C. albicans was evaluated. Minimum inhibitory concentration (MIC) and biofilm inhibitory concentration (BIC) of piperine and cinnamaldehyde against C. albicans were analysed through microbroth dilution assay and crystal violet staining method, respectively. Combinatorial biofilm and hyphal inhibitory effect were investigated through checkerboard assay. In vitro results were validated through gene expression analysis. BIC of piperine and cinnamaldehyde was determined to be 32 µg/mL and 64 µg/mL, respectively. Interaction between these two phytocomponents was found to be synergistic and six different synergistic antibiofilm combinations were identified. Microscopic analysis of biofilm architecture also evidenced the biofilm and surface adherence inhibitory potential of piperine and cinnamaldehyde combinations. Phenotypic switching between yeast and hyphal morphological forms was influenced by synergistic combinations. qPCR analysis corroborated the results of in vitro activities. nrg1 and trp1, the negative transcriptional regulators of filamentous growth were upregulated whereas other genes that are involved in biofilm formation, filamentous growth, adhesion etc were found to be downregulated. These proficient phytochemical combinations provide a new therapeutic avenue for the treatment of biofilm associated oral candidiasis and to combat the recurrent infections due to antibiotic resistance.},
}
@article {pmid35660567,
year = {2022},
author = {Lian, S and Qu, Y and Dai, C and Li, S and Jing, J and Sun, L and Yang, Y},
title = {Succession of function, assembly, and interaction of microbial community in sequential batch biofilm reactors under selenite stress.},
journal = {Environmental research},
volume = {},
number = {},
pages = {113605},
doi = {10.1016/j.envres.2022.113605},
pmid = {35660567},
issn = {1096-0953},
abstract = {The mechanism of interaction between selenite, a toxic substance, and the microbial community in wastewater is still not well understood. Herein, a sequencing batch biofilm reactor was used to systematically investigate the response of the microbial community to the continuous selenite stress. The results showed that selenite affected the reactor performance and reduced the biofilm mass. Also, it increased the proportion of the living cells, and changed the protein and polysaccharide composition of the biofilm as well as cellular secretions. Selenite facilitated the removal of NO3-N, according to water-quality and bioinformatics analyses. As such, the selenite was converted into selenium nanoparticles. α-Diversity analysis further revealed that 20 μM selenite enhanced the microbial community resilience, while 200 μM selenite had the reverse effect. Community composition analysis showed that Variovorax, Rhizobium, and Simkania had positive correlations with selenite (P < 0.05). Functional prediction suggested that selenite changed the C, N, and S cycle functions. Furthermore, determinism dominated the community assembly process, and the deterministic proportion increased with the increase of selenite concentration. Network analysis showed that selenite improved the stability and positive correlation ratio of the overall microbial network, and accelerated the communication between microorganisms. However, when compared with the 20 μM selenite, the 200 μM selenite boosted the competition and parasitism/predation among microorganisms. Low-abundance genera played a key role in the network of selenite-reducing microbial community. In addition, under selenite stress, biofilm network exhibited better stability and faster information exchange than suspended network, and the positive association between biofilm and suspended microorganisms increased. All in all, this research sheds light on the interaction between selenite and microbial community, as well as provides crucial information on selenium-containing wastewater.},
}
@article {pmid35660455,
year = {2022},
author = {Luan, YN and Yin, Y and An, Y and Zhang, F and Wang, X and Zhao, F and Xiao, Y and Liu, C},
title = {Investigation of an intermittently-aerated moving bed biofilm reactor in rural wastewater treatment under low dissolved oxygen and C/N condition.},
journal = {Bioresource technology},
volume = {358},
number = {},
pages = {127405},
doi = {10.1016/j.biortech.2022.127405},
pmid = {35660455},
issn = {1873-2976},
abstract = {An intermittently-aerated moving bed biofilm reactor (MBBR) was proposed for nitrogen and carbon removal from low C/N synthetic rural wastewater. In purposes of low energy consumption and costs, the intermittent aeration modes were changed and the dissolved oxygen was reduced gradually during the operation. The results showed that effluent concentrations of ammonia nitrogen and chemical oxygen demand were lower than 15 and 50 mg/L, respectively, even under microaerobic condition (0.1-1.0 mg/L). Meanwhile, the simultaneous nitrification-denitrification was achieved by intermittent aeration. The activity of functional bacteria was still high and the proportion of autotrophic biomass increased significantly under intermittent micro-aeration mode, which improved the nitrification performance. Aerobic denitrifier Hydrogenophaga, anoxic denitrifier Thiothrix, and heterotrophic nitrifier such as Rhodobacter were enriched in the intermittently micro-aerated MBBR, which will provide an applicable solution for rural wastewater treatment under low C/N and costs.},
}
@article {pmid35659363,
year = {2022},
author = {Brunke, MS and Konrat, K and Schaudinn, C and Piening, B and Pfeifer, Y and Becker, L and Schwebke, I and Arvand, M},
title = {Tolerance of biofilm of a carbapenem-resistant Klebsiella pneumoniae involved in a duodenoscopy-associated outbreak to the disinfectant used in reprocessing.},
journal = {Antimicrobial resistance and infection control},
volume = {11},
number = {1},
pages = {81},
pmid = {35659363},
issn = {2047-2994},
abstract = {BACKGROUND: One possible transmission route for nosocomial pathogens is contaminated medical devices. Formation of biofilms can exacerbate the problem. We report on a carbapenemase-producing Klebsiella pneumoniae that had caused an outbreak linked to contaminated duodenoscopes. To determine whether increased tolerance to disinfectants may have contributed to the outbreak, we investigated the susceptibility of the outbreak strain to disinfectants commonly used for duodenoscope reprocessing. Disinfection efficacy was tested on planktonic bacteria and on biofilm.<br><br>METHODS: Disinfectant efficacy testing was performed for planktonic bacteria according to EN standards 13727 and 14561 and for biofilm using the Bead Assay for Biofilms. Disinfection was defined as ≥ 5log10 reduction in recoverable colony forming units (CFU).<br><br>RESULTS: The outbreak strain was an OXA-48 carbapenemase-producing K. pneumoniae of sequence type 101. We found a slightly increased tolerance of the outbreak strain in planktonic form to peracetic acid (PAA), but not to other disinfectants tested. Since PAA was the disinfectant used for duodenoscope reprocessing, we investigated the effect of PAA on biofilm of the outbreak strain. Remarkably, disinfection of biofilm of the outbreak strain could not be achieved by the standard PAA concentration used for duodenoscope reprocessing at the time of outbreak. An increased tolerance to PAA was not observed in a K. pneumoniae type strain tested in parallel.<br><br>CONCLUSIONS: Biofilm of the K. pneumoniae outbreak strain was tolerant to standard disinfection during duodenoscope reprocessing. This study establishes for the first time a direct link between biofilm formation, increased tolerance to disinfectants, reprocessing failure of duodenoscopes and nosocomial transmission of carbapenem-resistant K. pneumoniae.},
}
@article {pmid35658710,
year = {2022},
author = {Goodyear, MC and Garnier, NE and Levesque, RC and Khursigara, CM},
title = {Liverpool Epidemic Strain Isolates of Pseudomonas aeruginosa Display High Levels of Antimicrobial Resistance during Both Planktonic and Biofilm Growth.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0102422},
doi = {10.1128/spectrum.01024-22},
pmid = {35658710},
issn = {2165-0497},
abstract = {Eight isolates of the Liverpool epidemic strain (LES) of Pseudomonas aeruginosa have previously been characterized using comparative genomics and preliminary phenotypic assays. Here, we extend the characterization of these clinically relevant P. aeruginosa isolates with planktonic and biofilm growth assays and analysis of antibiotic susceptibility for both planktonic and biofilm cultures. Laboratory strains PAO1 and PA14 were included as comparator strains. Antibiotic susceptibility to eight classes of antibiotics was determined. MICs were determined to measure susceptibility of planktonic cultures, and minimum biofilm eradication concentration (MBEC) assays were used to estimate levels of resistance during the production of biofilm. LES isolates had high levels of resistance compared with laboratory reference strains when grown planktonically (up to nine 2-fold dilutions higher), and resistance was increased in the biofilm mode of growth. Measurements of biofilm biomass in the MBEC assays showed that certain isolates often show increased biofilm biomass in the presence of antibiotics. IMPORTANCE Pseudomonas aeruginosa is an opportunistic pathogen with high intrinsic antibiotic resistance. This resistance is typically increased in clinical isolates through adaptations to the host and production of small-colony variants (SCVs) and when P. aeruginosa forms biofilms, which are surface-attached communities that are protected by a self-produced matrix. Understanding the combination of SCVs, biofilm production, and the diversity of drug resistance phenotypes in clinical isolates can lead to improved treatments for P. aeruginosa infections.},
}
@article {pmid35655342,
year = {2022},
author = {Ma, LZ and Wang, D and Liu, Y and Zhang, Z and Wozniak, DJ},
title = {Regulation of Biofilm Exopolysaccharide Biosynthesis and Degradation in Pseudomonas aeruginosa.},
journal = {Annual review of microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1146/annurev-micro-041320-111355},
pmid = {35655342},
issn = {1545-3251},
abstract = {Microbial communities enmeshed in a matrix of macromolecules, termed as biofilms, are the natural setting of bacteria. Exopolysaccharide is a critical matrix component of biofilms. Here, we focus on biofilm matrix exopolysaccharides in Pseudomonas aeruginosa. This opportunistic pathogen can adapt to a wide range of environments and can form biofilms or aggregates in a variety of surfaces or environments, such as the lungs of people with cystic fibrosis, catheters, wounds, and contact lenses. The ability to synthesize multiple exopolysaccharides is one of the advantages that facilitate bacterial survival in different environments. P. aeruginosa can produce several exopolysaccharides, including alginate, Psl, Pel, and lipopolysaccharide. In this review, we highlight the roles of each exopolysaccharide in P. aeruginosa biofilm development and how bacteria coordinate the biosynthesis of multiple exopolysaccharides and bacterial motility. In addition, we present advances in antibiofilm strategies targeting matrix exopolysaccharides, with a focus on glycoside hydrolases. Expected final online publication date for the Annual Review of Microbiology, Volume 76 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.},
}
@article {pmid35655210,
year = {2022},
author = {Azara, E and Longheu, CM and Attene, S and Sanna, S and Sale, M and Addis, MF and Tola, S},
title = {Comparative profiling of agr locus, virulence, and biofilm-production genes of human and ovine non-aureus staphylococci.},
journal = {BMC veterinary research},
volume = {18},
number = {1},
pages = {212},
pmid = {35655210},
issn = {1746-6148},
mesh = {Adhesins, Bacterial/genetics ; Animals ; *Biofilms ; Enterotoxins ; Female ; Humans ; Sheep ; *Staphylococcus/genetics ; Virulence/genetics ; },
abstract = {BACKGROUND: In a collaboration between animal and human health care professionals, we assessed the genetic characteristics shared by non-aureus staphylococci (NAS) infecting humans and dairy ewes to investigate their relatedness in a region concentrating half of the total National sheep stock. We examined by PCR 125 ovine and 70 human NAS for biofilm production, pyrogenic toxins, adhesins, autolysins genes, and accessory gene regulator (agr) locus. The microtiter plate assay (MPA) was used for the phenotypic screening of biofilm production. Ovine NAS included S. epidermidis, S. chromogenes, S. haemolyticus, S. simulans, S. caprae, S. warneri, S. saprophyticus, S. intermedius, and S. muscae. Human NAS included S. haemolyticus, S. epidermidis, S. hominis, S. lugdunensis, S. capitis, S. warneri, S. xylosus, S. pasteuri, and S. saprophyticus subsp. bovis.<br><br>RESULTS: Phenotypically, 41 (32.8%) ovine and 24 (34.3%) human isolates were characterized as biofilm producers. Of the ovine isolates, 12 were classified as biofilm-producing while the remaining 29 as weak biofilm-producing. All 24 human isolates were considered weak biofilm-producing. Few S. epidermidis isolates harbored the icaA/D genes coding for the polysaccharide intercellular adhesin (PIA), while the bhp, aap, and embp genes coding biofilm accumulation proteins were present in both non-producing and biofilm-producing isolates. Fifty-nine sheep NAS (all S. epidermidis, 1 S. chromogenes, and 1 S. haemolyticus) and 27 human NAS (all S. epidermidis and 1 S. warneri) were positive for the agr locus: agr-3se (57.8%) followed by agr-1se (36.8%) predominated in sheep, while agr-1se (65.4%), followed by agr-2se (34.6%) predominated in humans. Concerning virulence genes, 40, 39.2, 47.2%, 52.8, 80 and 43.2% of the sheep isolates carried atlE, aae, sdrF, sdrG, eno and epbS respectively, against 37.1, 42.8, 32.8, 60, 100 and 100% of human isolates. Enterotoxins and tsst were not detected.<br><br>CONCLUSIONS: Considerable variation in biofilm formation ability was observed among NAS isolates from ovine and human samples. S. epidermidis was the best biofilm producer with the highest prevalence of adhesin-encoding genes.},
}
@article {pmid35655208,
year = {2022},
author = {Przekwas, J and Gębalski, J and Kwiecińska-Piróg, J and Wiktorczyk-Kapischke, N and Wałecka-Zacharska, E and Gospodarek-Komkowska, E and Rutkowska, D and Skowron, K},
title = {The effect of fluoroquinolones and antioxidans on biofilm formation by Proteus mirabilis strains.},
journal = {Annals of clinical microbiology and antimicrobials},
volume = {21},
number = {1},
pages = {22},
pmid = {35655208},
issn = {1476-0711},
mesh = {Anti-Bacterial Agents/pharmacology ; Ascorbic Acid/pharmacology ; Biofilms ; Ciprofloxacin/pharmacology ; *Fluoroquinolones/pharmacology ; Humans ; Norfloxacin ; *Proteus mirabilis ; Rutin ; },
abstract = {BACKGROUND: Fluoroquinolones are a group of antibiotics used in urinary tract infections. Unfortunately, resistance to this group of drugs is currently growing. The combined action of fluoroquinolones and other antibacterial and anti-biofilm substances may extend the use of this therapeutic option by clinicians. The aim of the study was to determine the effect of selected fluoroquinolones and therapeutic concentrations of ascorbic acid and rutoside on biofilm formation by Proteus mirabilis.<br><br>MATERIALS AND METHODS: The study included 15 strains of P. mirabilis isolated from urinary tract infections in patients of the University Hospital No. 1 dr A. Jurasz in Bydgoszcz (Poland). The metabolic activity of the biofilm treated with 0.4 mg/ml ascorbic acid, 0.02 µg/ml rutoside and chemotherapeutic agents (ciprofloxacin, norfloxacin) in the concentration range of 0.125-4.0 MIC (minimum inhibitory concentration) was assessed spectrophotometrically.<br><br>RESULTS: Both ciprofloxacin and norfloxacin inhibited biofilm formation by the tested strains. The biofilm reduction rate was correlated with the increasing concentration of antibiotic used. No synergism in fluoroquinolones with ascorbic acid, rutoside or both was found. The ascorbic acid and rutoside combination, however, significantly decreased biofilm production.<br><br>CONCLUSIONS: Our research proves a beneficial impact of ascorbic acid with rutoside supplementation on biofilm of P. mirabilis strains causing urinary tract infections.},
}
@article {pmid35656684,
year = {2021},
author = {Arora, SS and Shetty, R and Hemagiriyappa, MS and Thakur, SS and Mishra, N and Lokhande, NM},
title = {Comparative Evaluation of Antibacterial Efficacy of Silver and Cadmium Nanoparticles and Calcium Hydroxide against Enterococcus faecalis Biofilm.},
journal = {The journal of contemporary dental practice},
volume = {22},
number = {12},
pages = {1438-1443},
pmid = {35656684},
issn = {1526-3711},
mesh = {Anti-Bacterial Agents/therapeutic use ; *Biofilms/drug effects ; *Cadmium/pharmacology ; *Calcium Hydroxide/pharmacology ; *Enterococcus faecalis/drug effects ; Gels ; *Metal Nanoparticles ; Root Canal Irrigants/pharmacology ; *Silver/pharmacology ; },
abstract = {AIM: The purpose of this study was to evaluate and compare the antibacterial efficacy of calcium hydroxide medicament, silver (AgNPs) and cadmium nanoparticles (CdSNPs) as medicament against the biofilms of Enterococcus faecalis on dentin sections. E. faecalis is commonly detected in asymptomatic and persistent endodontic infections.<br><br>METHODS: Twenty standard size dentin sections were prepared. E. faecalis was inoculated on these dentin sections for four weeks to form the bacterial biofilm. Twenty dentin sections were segregated into four different groups with five specimens in each group. Group I was kept as control group, and antibacterial efficacy was tested by treating biofilms with Ca(OH) 2 medicament, 0.02% AgNP and CdSNP gels for 7 days. The ultrastructure of biofilms from each group was examined under scanning electron microscope and was visually evaluated and compared for different groups.<br><br>RESULTS: Ca(OH)2 exhibited a slight disruption of E. faecalis biofilm. Both AgNP and CdSNP medicaments disrupted E. faecalis biofilm effectively after 7 days of inoculation. AgNPs disrupted the biofilm more effectively than CdSNPs. Biofilms in control group, which was irrigated with saline, did not show any disruption of biofilm, which could be seen as homogenous layer over most of dentin sections.<br><br>CONCLUSIONS: This study suggests that both AgNP and CdNP gels are effective against E. faecalis and can be used as a medicament to eliminate residual bacterial biofilms during root canal disinfection. AgNP medicament is more effective than CdNP, whereas Ca(OH) 2 is not effective against E. faecalis biofilms.<br><br>CLINICAL SIGNIFICANCE: Incomplete clearance and the development of antibiotic resistance in E. faecalis are the important factors for failure of root canal treatment. When cationic nanoparticles are introduced for the treatment of biofilms, it can interact with both extracellular polymeric substances and bacterial cells. The initial electrostatic attraction between positively charged nanoparticles and negatively charged bacterial surface leads to bacterial killing via the production of reactive oxygen species. Metal nanoparticles that are effective against E. faecalis have a significant potential role in the prevention and treatment of such cases, as bacteria do not develop resistance against metal nanoparticles.},
}
@article {pmid35655484,
year = {2022},
author = {Rajabi, H and Salimizand, H and Khodabandehloo, M and Fayyazi, A and Ramazanzadeh, R},
title = {Prevalence of algD, pslD, pelF, Ppgl, and PAPI-1 Genes Involved in Biofilm Formation in Clinical Pseudomonas aeruginosa Strains.},
journal = {BioMed research international},
volume = {2022},
number = {},
pages = {1716087},
doi = {10.1155/2022/1716087},
pmid = {35655484},
issn = {2314-6141},
mesh = {Biofilms ; Cross-Sectional Studies ; Humans ; Prevalence ; *Pseudomonas Infections/drug therapy/epidemiology/genetics ; *Pseudomonas aeruginosa ; },
abstract = {Introduction: Biofilm formation is one of the main virulence factors in Pseudomonas aeruginosa infections. This study is aimed at investigating the presence of genes involved in biofilm formation in clinical P. aeruginosa isolates. Material and Methods. A cross-sectional study was conducted on 112 P. aeruginosa isolates. The biofilm formation assay was performed on all isolates. Antimicrobial resistance was determined by the disk diffusion method, and the presence of genes was detected by polymerase chain reaction. Isolates were typed with Rep-PCR.<br><br>Results: The results of biofilm formation demonstrated that 85 strains (75.9%) were biofilm producers, and 27 strains (24.1%) were nonproducer isolates. Antibiotic susceptibility pattern in biofilm-positive and biofilm-negative isolates obtained from hospitalized patients showed a high rate of antibiotic resistance to amoxicillin with 95.7% and 92.3%, respectively. Based on PCR amplification results, the frequency of genes involved in biofilm formation among all isolates was as follows: algD (78.6%), pelF (70.5%), pslD (36.6%), Ppgl (0%), and PAPI-1 (77.6%). Rep-PCR typing demonstrated that 112 P. aeruginosa isolates were classified into 57 types according to 70% cut-off. The predominant type was A which contained 15 isolates. Moreover, 7 isolates were clustered in genotype B, followed by C type (6), D (4), E (4), F (4), G (4), H (3), I (3), J (3 isolates), and 12 genotypes, each containing two isolates. Also, 35 isolates were distributed in scattered patterns and showed single types.<br><br>Conclusion: Study results showed significant association between biofilm formation and resistance to antibiotics such as ceftazidime and meropenem. Analysis of Rep-PCR patterns indicated that the evaluated isolates were heterogeneous, relatively.},
}
@article {pmid35655421,
year = {2022},
author = {Fiallos, NM and Aguiar, ALR and Nascimento da Silva, B and Rocha, MFG and Sidrim, JJC and Castelo Branco de Souza Collares Maia, D and Cordeiro, RA},
title = {Enterococcus faecalis and Candida albicans dual-species biofilm: establishment of an in vitro protocol and characterization.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-13},
doi = {10.1080/08927014.2022.2084612},
pmid = {35655421},
issn = {1029-2454},
abstract = {Enterococcus faecalis is the most important agent of persistent apical periodontitis, and recently, Candida albicans has also been implicated in periapical infections. This study aimed to optimize an in vitro E. faecalis and C. albicans dual-species biofilm protocol for endodontic research. Different physicochemical conditions for biofilm formation were tested. Susceptibility assays to antimicrobials, biochemical composition and an ultra-morphological structure analyses were performed. Reproducible dual-species biofilms were established in BHI medium at 35 °C, for 48 h and in a microaerophilic atmosphere. An increase in biomass and chitin content was detected after vancomycin treatment. Structural analysis revealed that the dual-species biofilm was formed by both microorganisms adhered to the substrate. The proposed protocol could be useful for the study of interkingdom relationships and help to find new strategies against periapical infections.},
}
@article {pmid35653845,
year = {2022},
author = {Carneiro, RB and Gomes, GM and Zaiat, M and Santos-Neto, ÁJ},
title = {Two-phase (acidogenic-methanogenic) anaerobic fixed bed biofilm reactor enhances the biological domestic sewage treatment: Perspectives for recovering bioenergy and value-added by-products.},
journal = {Journal of environmental management},
volume = {317},
number = {},
pages = {115388},
doi = {10.1016/j.jenvman.2022.115388},
pmid = {35653845},
issn = {1095-8630},
abstract = {The organic matter bioconversion into methane during anaerobic digestion (AD) comprises different steps, the acidogenic and methanogenic phases being clearly distinct in terms of metabolic activities. In this work, new configurations of anaerobic fixed bed biofilm reactors (AFBBR) were operated under conventional methanogenic conditions (single phase - SP-AFBBR, M1R), and in a sequential two-phase system, acidogenic reactor followed by methanogenic reactor (TP-AFBBR, AcR + M2R), in order to verify the impact of the AD phase separation on the overall system performance in operational, kinetics and microbiological aspects. The results indicated that feeding the methanogenic reactor with the acidogenic effluent stream provided a shorter operating start-up period (11 and 32 days for SP and TP-AFBBR, respectively), a greater alkalinity generation (0.14 and 0.41 g-CaCO3·g-CODremoved-1 for M1R and M2R, respectively), and the optimization of biomethane production (methane yield of 95 and 154 N-mLCH4·g-CODremoved-1 for M1R and M2R, respectively). The COD removal kinetics was also favored in the TP-AFBBR (k1-COD = 1.4 and 2.9 h-1 for M1R and M2R, respectively), since the soluble fermentation products were readily bioavailable to the biomass in the reactor. Hydrogenotrophic methanogenesis was the predominant pathway in the M2R, while the Methanosaeta-driven acetoclastic pathway predominated in the M1R. The greater diversity of Bacteria and Archaea in M2R denotes a better balance between the species that degrade volatile organic acids from AcR (i.e. Syntrophorhabdus, Syntrophus and Syntrophobacter) and the hydrogenotrophic methanogens (Methanoregula, Methanolinea and Methanospirillum) that consume the biodegradation products. The estimated bioenergy generation potential (range of 0.39-0.64 kWh·m-3-sewage considering the COD removed) for full-scale TP-sewage treatment plants evidences the feasibility of energetic recovery in the domestic sewage anaerobic treatment.},
}
@article {pmid35651751,
year = {2022},
author = {Woitschach, F and Kloss, M and Schlodder, K and Borck, A and Grabow, N and Reisinger, EC and Sombetzki, M},
title = {Bacterial Adhesion and Biofilm Formation of Enterococcus faecalis on Zwitterionic Methylmethacrylat and Polysulfones.},
journal = {Frontiers in cellular and infection microbiology},
volume = {12},
number = {},
pages = {868338},
doi = {10.3389/fcimb.2022.868338},
pmid = {35651751},
issn = {2235-2988},
abstract = {Biofilm-associated implant infections represent a major challenge for healthcare systems around the world due to high patient burden and enormous costs incurred. Enterococcus faecalis (E. faecalis) is the most prevalent enterococcal species identified in biofilm-associated infections. The steadily growing areas of application of implants demand a solution for the control of bacterial infections. Therefore, the development of modified anti-microbial implant materials and the testing of the behavior of different relevant bacterial strains towards them display an indispensable task. Recently, we demonstrated an anti-microbial effect of zwitterionic modified silicone rubber (LSR) against Staphylococcus aureus. The aim of this study was to evaluate bacterial colonization and biofilm formation of another clinically relevant strain, E. faecalis, on this material in comparison to two of the most commonly used thermoplastic polyurethanes (TPUs) and other modified LSR surfaces. By generating growth curves, crystal violet, and fluorescence staining, as well as analyzing the expression of biofilm-associated genes, we demonstrated no anti-microbial activity of the investigated materials against E. faecalis. These results point to the fact that anti-microbial effects of novel implant materials do not always apply across the board to all bacterial strains.},
}
@article {pmid35651015,
year = {2022},
author = {Wang, Y and Sun, L and Hu, L and Wang, Z and Wang, X and Dong, Q},
title = {Adhesion and kinetics of biofilm formation and related gene expression of Listeria monocytogenes in response to nutritional stress.},
journal = {Food research international (Ottawa, Ont.)},
volume = {156},
number = {},
pages = {111143},
doi = {10.1016/j.foodres.2022.111143},
pmid = {35651015},
issn = {1873-7145},
abstract = {Listeria monocytogenes is a gram-positive pathogen, that usually adheres to stainless steel (SS), and other abiotic surfaces in food processing that undergo repeated cleaning and cause the spread of Listeria. Through the enumeration of biofilm cells, extracellular polymeric substance (EPS) component and the scanning electron microscopy (SEM) analysis of biofilms, it was found that the ratio of cells and extracellular matrix is affected by nutrition status. Regardless of the temperature, all strains exhibited a higher adhesion ability when exposed to 10-fold diluted TSB-YE (DTSB-YE, nutrition deficiency). Three hour initial adhesion was significantly positively correlated with biofilm formation (p＜0.01). DTSB-YE enhances initial attachment and subsequently promotes biofilm formation. The SEM analysis also showed that in DTSB-YE the adhesion and covered area of the attached cells were higher than those in TSB-YE (rich media). The amount of both extracellular polysaccharides and proteins was significantly higher when incubated in DTSB-YE than TSB-YE. The highest biofilm formation of Lm83 was observed in DTSBYE independent of temperature. The effects of nutrition deficiency on the expression of critical biofilm-associated genes of Lm 83 planktonic and biofilm cells were measured. The gene expression levels of inlA and sigB in biofilm cells in TSB-YE and DTSB-YE were approximately 95.7% and 88.0% and 42.2% and 45.7% lower than those in planktonic cells, respectively. However, the expression of inlA in DTSB-YE was significantly higher (p＜0.05) than that in TSB-YE for the same cell state. Interestingly, the gene expression of motB was considerably higher in DTSB-YE than in TSBYE, regardless of the state. These results indicate that better cell motility in nutrient deficiencies might facilitate the cell aggression to promote biofilm formation.},
}
@article {pmid35650279,
year = {2022},
author = {Kumar, R and Singh, N and Chauhan, A and Kumar, M and Bhatta, RS and Singh, SK},
title = {Mycobacterium tuberculosis survival and biofilm formation studies: effect of D-amino acids, D-cycloserine and its components.},
journal = {The Journal of antibiotics},
volume = {},
number = {},
pages = {},
pmid = {35650279},
issn = {1881-1469},
support = {MLP2033//CSIR | Central Drug Research Institute (CDRI)/ ; EMR/2017/001295//DST | Science and Engineering Research Board (SERB)/ ; },
abstract = {D-amino acids play an important role in cell wall peptidoglycan biosynthesis. Mycobacterium tuberculosis D-amino acid oxidase deletion led to reduced biofilm-forming ability. Other recent studies also suggest that the accumulation of D-amino acids blocks biofilm formation and could also disperse pre-formed biofilm. Biofilms are communities of bacterial cells protected by extracellular matrix and harbor drug-tolerant as well as persistent bacteria. In Mycobacterium tuberculosis, biofilm formation or its inhibition by D-amino acids is yet to be tested. In the present study, we used selected D-amino acids to study their role in the prevention of biofilm formation and also if D-cycloserine's activity was due to presence of D-Serine as a metabolite. It was observed that D-serine limits biofilm formation in Mycobacterium tuberculosis H37Ra (Mtb-Ra), but it shows no effect on pre-formed biofilm. Also, D-cycloserine and its metabolic product, hydroxylamine, individually and in combination, with D-Serine, limit biofilm formation in Mtb-Ra and also disrupts existing biofilm. In summary, we demonstrated that D-alanine, D-valine, D-phenylalanine, D-serine, and D-threonine had no disruptive effect on pre-formed biofilm of Mtb-Ra, either individually or in combination, and D-cycloserine and its metabolite hydroxylamine have potent anti-biofilm activity.},
}
@article {pmid35649316,
year = {2022},
author = {Forero-Doria, O and Parra-Cid, C and Venturini, W and Espinoza, C and Araya-Maturana, R and Valenzuela-Riffo, F and Saldias, C and Leiva, A and Duarte, Y and Echeverría, J and Guzmán, L},
title = {Novel N-benzoylimidazolium ionic liquids derived from benzoic and hydroxybenzoic acids as therapeutic alternative against Biofilm-forming bacteria in skin and soft-tissue infections.},
journal = {Bioorganic chemistry},
volume = {126},
number = {},
pages = {105914},
doi = {10.1016/j.bioorg.2022.105914},
pmid = {35649316},
issn = {1090-2120},
abstract = {The skin and soft tissue infections (SSTIs) -producing pathogens have acquired resistance to a wide range of antimicrobials, thus it is highly relevant to have new treatment alternatives. In this study, we report the synthesis, characterization, and antibacterial activity of three novel series of ionic liquids (ILs) derived from benzoic and hydroxybenzoic acids, with different lengths of the alkyl chain. The minimum inhibitory concentration (MIC) were tested in Gram-positive: Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Streptococcus pyogenes, and Gram-negative: Acinetobacter baumannii and Escherichia coli, showing a MIC range of 0.01562-2.0 mM, with the activity varying according to the aromatic ring functionalization and the length of the alkyl chains. Regarding the antibiofilm activity, different efficacy was observed among the different ILs, some of them presenting antibiofilm activities close to 80% as in the case of those derived from syringic acid with an alkyl chain of six carbon atoms against Pseudomonas aeruginosa. Furthermore, the cell viability in HaCaT cells was determined, showing a half maximal effective concentration (EC50) values higher than the MIC values. The antimicrobial and antibiofilm results, along with not producing cellular toxicity at the MIC values shows that these ILs could be a promising alternative against SSTIs.},
}
@article {pmid35648454,
year = {2022},
author = {Qiu, M and Feng, L and Zhao, C and Gao, S and Bao, L and Zhao, Y and Fu, Y and Hu, X},
title = {Commensal Bacillus subtilis from cow milk inhibits Staphylococcus aureus biofilm formation and mastitis in mice.},
journal = {FEMS microbiology ecology},
volume = {},
number = {},
pages = {},
doi = {10.1093/femsec/fiac065},
pmid = {35648454},
issn = {1574-6941},
abstract = {The colonization and virulence production of Staphylococcus aureus (S. aureus), a known pathogen that induces mastitis, depend on its quorum-sensing (QS) system and biofilm formation. It has been reported that Bacillus can inhibit the QS system of S. aureus, thereby reducing S. aureus colonization in the intestine. However, whether Bacillus affects S. aureus biofilm formation and consequent colonization during mastitis is still unknown. In this study, the differences in the colonization of S. aureus and Bacillus were first analyzed by isolating and culturing bacteria from milk samples. It was found that the colonization of Bacillus and S. aureus in cow mammary glands was negatively correlated. Secondly, we found that although Bacillus did not affect S. aureus growth, it inhibited the biofilm formation of S. aureus by interfering its QS signaling. The most significant anti-biofilm effect was found in Bacillus subtilis H28 (B. subtilis H28). Finally, we found that B. subtilis H28 treatment alleviated S. aureus-induced mastitis in a mice model. Our results rerealed that bovine milk derived commensal Bacillus inhibited S. aureus colonization and alleviated S. aureus-induced mastitis by influencing biofilm formation, suggesting a potential targeted strategy to limit the colonization of S. aureus in vivo.},
}
@article {pmid35648339,
year = {2022},
author = {Liu, ZH and Chiang, MT and Lin, HY},
title = {Lytic Bacteriophage as a Biomaterial to Prevent Biofilm Formation and Promote Neural Growth.},
journal = {Tissue engineering and regenerative medicine},
volume = {},
number = {},
pages = {},
pmid = {35648339},
issn = {2212-5469},
support = {MOST 110-2637-E-027-006//Ministry of Science and Technology, Taiwan/ ; },
abstract = {BACKGROUND: Although non-lytic filamentous bacteriophages have been made into biomaterial to guide tissue growth, they had limited ability to prevent bacterial infection. In this work a lytic bacteriophage was used to make an antibacterial biomaterial for neural tissue repair.<br><br>METHODS: Lytic phages were chemically bound to the surface of a chitosan film through glutaraldehyde crosslinking. After the chemical reaction, the contact angle of the sample surface and the remaining lytic potential of the phages were measured. The numbers of bacteria on the samples were measured and examined under scanning electron microscopy. Transmission electron microscopy (TEM) was used to observe the phages and phage-infected bacteria. A neuroblast cell line was cultured on the samples to evaluate the sample's biocompatibility.<br><br>RESULTS: The phages conjugated to the chitosan film preserved their lytic potential and reduced 68% of bacterial growth on the sample surface at 120 min (p < 0.001). The phage-linked surface had a significantly higher contact angle than that of the control chitosan (p < 0.05). After 120 min a bacterial biofilm appeared on the control chitosan, while the phage-linked sample effectively prevented biofilm formation. The TEM images demonstrated that the phage attached and lysed the bacteria on the phage-linked sample at 120 min. The phage-linked sample significantly promoted the neuroblast cell attachment (p < 0.05) and proliferation (p < 0.01). The neuroblast on the phage-linked sample demonstrated more cell extensions after day 1.<br><br>CONCLUSION: The purified lytic phages were proven to be a highly bioactive nanomaterial. The phage-chitosan composite material not only promoted neural cell proliferation but also effectively prevent bacterial growth, a major cause of implant failure and removal.},
}
@article {pmid35647620,
year = {2022},
author = {Lee, JH and Kim, YG and Lee, J},
title = {Inhibition of Staphylococcus aureus Biofilm Formation and Virulence Factor Production by Petroselinic Acid and Other Unsaturated C18 Fatty Acids.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0133022},
doi = {10.1128/spectrum.01330-22},
pmid = {35647620},
issn = {2165-0497},
abstract = {Staphylococcus aureus is a major human pathogen that secretes several toxins associated with the pathogenesis of sepsis and pneumonia. Its antibiotic resistance is notorious, and its biofilms play a critical role in antibiotic tolerance. We hypothesized fatty acids might inhibit S. aureus biofilm formation and the expressions of its virulence factors. Initially, the antibiofilm activities of 27 fatty acids against a methicillin-sensitive S. aureus strain were investigated. Of the fatty acids tested, three C18 unsaturated fatty acids, that is, petroselinic, vaccenic, and oleic acids at 100 μg/mL, inhibited S. aureus biofilm formation by more than 65% without affecting its planktonic cell growth (MICs were all > 400 μg/mL). Notably, petroselinic acid significantly inhibited biofilm formation of two methicillin-resistant S. aureus strains and two methicillin-sensitive S. aureus strains. In addition, petroselinic acid significantly suppressed the production of three virulence factors, namely, staphyloxanthin, lipase, and α-hemolysin. Transcriptional analysis showed that petroselinic acid repressed the gene expressions of quorum sensing regulator agrA, effector of quorum sensing RNAIII, α-hemolysin hla, nucleases nuc1 and nuc2, and the virulence regulator saeR. Furthermore, petroselinic acid dose-dependently inhibited S. aureus biofilm formation on abiotic surfaces and porcine skin. These findings suggest that fatty acids, particularly petroselinic acid, are potentially useful for controlling biofilm formation by S. aureus. IMPORTANCE Fatty acids with a long carbon chain have recently attracted attention because of their antibiofilm activities against microbes. Here, we report the antibiofilm activities of 27 fatty acids against S. aureus. Of the fatty acids tested, three C18 unsaturated fatty acids (petroselinic, vaccenic, and oleic acids) significantly inhibited biofilm formation by S. aureus. Furthermore, petroselinic acid inhibited the production of several virulence factors in S. aureus. The study also reveals that the action mechanism of petroselinic acid involves repression of quorum-sensing-related and virulence regulator genes. These findings show that natural and nontoxic petroselinic acid has potential use as a treatment for S. aureus infections, including infections by methicillin-resistant S. aureus strains, and in food processing facilities.},
}
@article {pmid35645826,
year = {2022},
author = {Meng, Q and Lin, F and Ling, B},
title = {In Vitro Activity of Peptide Antibiotics in Combination With Other Antimicrobials on Extensively Drug-Resistant Acinetobacter baumannii in the Planktonic and Biofilm Cell.},
journal = {Frontiers in pharmacology},
volume = {13},
number = {},
pages = {890955},
doi = {10.3389/fphar.2022.890955},
pmid = {35645826},
issn = {1663-9812},
abstract = {Acinetobacter baumannii is one of the most dangerous opportunistic pathogens in the global health care setup. Its drug resistance and biofilm-forming capability are often associated with chronic infections that are difficult to treat. Therefore, the clinical treatments for highly drug-resistant A. baumannii are limited. Antimicrobial peptides are broad-spectrum antibacterial agents combined with antibiotics that minimize selective bacterial resistance and enhance antibacterial efficacy. The current study evaluated the synergistic antibacterial activities of clinically important peptide antibiotics combined with other antimicrobials against nine extensively drug-resistant A. baumannii strains in planktonic and biofilm cells in vitro. Polymyxin B and E combined with imipenem showed 100% synergy in the planktonic cell with the checkerboard. Moreover, polymyxin E with rifampicin and bacitracin with imipenem or meropenem showed 100% additive effects. In the biofilm cell, polymyxin B and E combined with azithromycin showed 100% synergy, when vancomycin with azithromycin, rifampicin, and bacitracin with azithromycin or rifampicin, and teicoplanin with tigecycline or rifampicin, all showed 100% additive effects. Therefore, peptide antibiotics combined with other antimicrobials have synergistic or additive effects on extensively drug-resistant A. baumannii in planktonic and biofilm cells. In addition, the combination of polymyxins with carbapenems or azithromycin could be an ideal therapy against extensively drug-resistant A. baumannii infections.},
}
@article {pmid35645800,
year = {2022},
author = {Shah, AB and Baiseitova, A and Kim, JH and Lee, YH and Park, KH},
title = {Inhibition of Bacterial Neuraminidase and Biofilm Formation by Ugonins Isolated From Helminthostachys Zeylanica (L.) Hook.},
journal = {Frontiers in pharmacology},
volume = {13},
number = {},
pages = {890649},
doi = {10.3389/fphar.2022.890649},
pmid = {35645800},
issn = {1663-9812},
abstract = {Bacterial neuraminidase (BNA) plays a pivotal role in the pathogenesis of several microbial diseases including biofilm formation. The aim of this study is to reveal the neuraminidase inhibitory potential of metabolites from Helminthostachys zeylanica (L.) Hook. which have diverse biological activities including PTP1B and α-glucosidase. The six ugonins (1-6) from the target plant showed significant neuraminidase inhibition. The inhibitory potencies were observed at a nanomolar level of 35-50 nM, which means they are 100 times more active than their corresponding mother compounds (eriodyctiol and luteolin). A detailed kinetic study revealed that all ugonins were reversible noncompetitive inhibitors. An in-depth investigation of the most potent compound 1 showed its time-dependent inhibition with the isomerization model having k 5 = 0.0103 min-1, k 6 = 0.0486 min-1, and K i app = 0.062 μM. The binding affinities (K sv) were agreed closely with our prediction based on the inhibitory potencies. Particularly, ugonin J (1) blocked the biofilm formation of E. coli dose-dependently up to 150 µM without the inhibition of bacteria. The major compounds (1-6) in the extract were characterized by UPLC-ESI-Q-TOF/MS.},
}
@article {pmid35644451,
year = {2022},
author = {Lu, W and Zhang, X and Zhang, Y and Wang, Q and Wei, Y and Ma, B},
title = {Synergistic simultaneous endogenous partial denitrification/anammox (EPDA) and denitrifying dephosphatation for advanced nitrogen and phosphorus removal in a complete biofilm system.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {127378},
doi = {10.1016/j.biortech.2022.127378},
pmid = {35644451},
issn = {1873-2976},
abstract = {To achieve simultaneous biological nitrogen and phosphorus removal from municipal wastewater, the endogenous partial denitrification/anammox (EPDA) was combined with denitrifying dephosphatation in a complete biofilm reactor. Advanced nitrogen and phosphorus removal were achieved with effluent total nitrogen (TN) and PO43--P concentrations of 7.77 ± 0.33 mg/L and 0.35 ± 0.10 mg/L, respectively. Anammox took a major role in the system, accounting for 76 ± 7% of nitrogen removal. 16S rRNA high-throughput sequencing results showed that the anammox bacteria co-existed with the denitrifying glycogen accumulating organisms (DGAOs) and the denitrifying phosphorus accumulating organisms (DPAOs). Anammox bacteria were mainly distributed in the inner layer, while DGAOs and DPAOs existed in the outer layer of EPDA biofilms. Furthermore, based on the EPDA biofilm system, a promising advanced nitrogen and phosphorus removal process was suggested to achieve lower requirements for energy and reagent consumption.},
}
@article {pmid35643294,
year = {2022},
author = {Villarreal-Salazar, V and Bocanegra-Ibarias, P and Villarreal-Treviño, L and Salas-Treviño, D and Morfin-Otero, R and Camacho-Ortiz, A and Flores-Treviño, S},
title = {Improvement of antimicrobial susceptibility testing in biofilm-growingcoagulase-negative Staphylococcus hominis.},
journal = {Journal of microbiological methods},
volume = {},
number = {},
pages = {106493},
doi = {10.1016/j.mimet.2022.106493},
pmid = {35643294},
issn = {1872-8359},
abstract = {Coagulase-negative Staphylococcus hominis causes bloodstream infections and often can form biofilms on medical devices. This study aimed to improve the current methodology for antimicrobial susceptibility testing (AST) in biofilm-growing S. hominis isolates. Biofilm production of S. hominis was assessed using the crystal violet staining method in trypticase soy broth supplemented with 1% glucose (TSBglu1%), Mueller-Hinton broth (MHB), or MHBglu1% using flat-bottom plates or the Calgary device. Susceptibility to antibiotics was assessed using the broth microdilution method (MHB and TSBglu1%) in planktonic cells (round-bottom plates) and biofilm cells (flat-bottom plates and the Calgary device). Biofilm determination using TSBglu1% yielded better performance over MHB, and flat-bottom plates without agitation were preferred over the Calgary device. Higher fold dilution values between the minimum biofilm eradication concentration (MBEC) and the minimum inhibitory concentration (MIC) were obtained in MHB for almost all antibiotics, except for linezolid. TSBglu1% and flat-bottom polystyrene plates were preferred over MHB and the Calgary device for biofilm determination. AST in biofilm-growing S. hominis showed better performance using TSBglu1% compared to MHB. Therefore, when comparing MBEC and MIC values, AST in planktonic cells could also be performed using TSBglu1% instead of MHB.},
}
@article {pmid35642853,
year = {2022},
author = {Wang, H and Chen, C and Yang, E and Tu, Z and Liang, J and Dai, X and Chen, H},
title = {Revealing the effect of biofilm formation in partial nitritation-anammox systems: Start-up, performance stability, and recovery.},
journal = {Bioresource technology},
volume = {357},
number = {},
pages = {127379},
doi = {10.1016/j.biortech.2022.127379},
pmid = {35642853},
issn = {1873-2976},
abstract = {Successful application of partial nitritation-anammox (PNA) processes is currently and primarily associated with biofilm systems. Biofilm characteristics significantly influence start-up, performance stability, and recovery. Here, two PNA systems with and without carriers were implemented simultaneously for treating wastewater containing 50 mg-NH4/L. The performance characteristics of these two PNA systems were compared. Stable nitrogen removal efficiencies of 76.3 ± 2.8% and 72.9 ± 1.6% were obtained for suspended sludge and biofilm systems, respectively. The slow process of biofilm colonization resulted in a long start-up time in the biofilm system. Biofilm enrichment and protection conferred stable performance when exposed to aeration shock. The suspended sludge system displayed good elasticity during performance recovery after shock compared to the slow recovery in the biofilm system. Moreover, suitable control of dissolved oxygen could improve the activity and abundance of the functional microbes. This study provides new insights into the operation and control of PNA systems for treating mainstream wastewater.},
}
@article {pmid35642782,
year = {2022},
author = {Moore-Ott, JA and Chiu, S and Amchin, DB and Bhattacharjee, T and Datta, SS},
title = {A biophysical threshold for biofilm formation.},
journal = {eLife},
volume = {11},
number = {},
pages = {},
doi = {10.7554/eLife.76380},
pmid = {35642782},
issn = {2050-084X},
support = {CBET-1941716//National Science Foundation/ ; EF-2124863//National Science Foundation/ ; DMR-2011750//National Science Foundation/ ; Pew Biomedical Scholars Program//Pew Charitable Trusts/ ; DGE-1656466//National Science Foundation/ ; Eric and Wendy 708 Schmidt Transformative Technology Fund//Princeton University/ ; Princeton Catalysis Initiative//Princeton University/ ; Reiner G. Stoll Undergraduate Summer Fellowship//Princeton University/ ; },
abstract = {Bacteria are ubiquitous in our daily lives, either as motile planktonic cells or as immobilized surface-attached biofilms. These different phenotypic states play key roles in agriculture, environment, industry, and medicine; hence, it is critically important to be able to predict the conditions under which bacteria transition from one state to the other. Unfortunately, these transitions depend on a dizzyingly complex array of factors that are determined by the intrinsic properties of the individual cells as well as those of their surrounding environments, and are thus challenging to describe. To address this issue, here, we develop a generally-applicable biophysical model of the interplay between motility-mediated dispersal and biofilm formation under positive quorum sensing control. Using this model, we establish a universal rule predicting how the onset and extent of biofilm formation depend collectively on cell concentration and motility, nutrient diffusion and consumption, chemotactic sensing, and autoinducer production. Our work thus provides a key step toward quantitatively predicting and controlling biofilm formation in diverse and complex settings.},
}
@article {pmid35642502,
year = {2022},
author = {Schoepflin, S and Macmanus, J and Long, C and McCullough, K and Klaus, S and De Clippeleir, H and Wilson, C and Parsons, M and Chandran, K and Bott, C},
title = {Startup strategies for mainstream anammox polishing in moving bed biofilm reactors.},
journal = {Water environment research : a research publication of the Water Environment Federation},
volume = {94},
number = {6},
pages = {e10723},
doi = {10.1002/wer.10723},
pmid = {35642502},
issn = {1554-7531},
support = {84008601/EPA/EPA/United States ; 84008601/EPA/EPA/United States ; },
abstract = {This study evaluated startup strategies for mainstream polishing anammox moving bed biofilm reactors (MBBRs) without anammox bacterial (AMX) biomass inoculation. Two types of startups were tested: anammox only (no external carbon addition) and partial denitrification/anammox (PdNA) with glycerol addition. Reactors were started with either virgin carriers or carriers with a preliminary biofilm from a mainstream aerobic integrated fixed-film activated sludge (IFAS) process. Three pilot-scale startups were completed under the following conditions: anammox-only with preliminary biofilm carriers, PdNA with preliminary biofilm carriers, and PdNA with virgin carriers. AMX presence was confirmed via quantitative polymerase chain reaction (qPCR) after 57, 57, and 77 days, respectively. Prior to AMX detection, average influent concentrations of ammonia and nitrite ranged from 1.7-2.7 mg/L and 0.98-1.8 mg/L, respectively. This study demonstrated that AMX can be grown on carriers without AMX seeding under mainstream conditions (temperature 17-29°C, low ammonia and nitrite), regardless of whether nitrite came from upstream or partial denitrification within the reactor. This study also showed that using preliminary biofilm carriers can decrease startup time by approximately 1 month. These results address critical questions for moving mainstream anammox processes to full-scale implementation, and suggest that PdNA MBBRs are feasible and sustainable for full-scale ammonia, nitrate, and nitrite polishing to meet stringent total nitrogen requirements. PRACTITIONER POINTS: This research will help utilities develop methods for starting up mainstream anammox MBBRs without the barrier of anammox biomass seeding. Preliminary biofilm carriers accelerated startup time in a PdNA MBBR, but a virgin carrier reactor started up in a similar timeframe, contrary to expectations. Also, contrary to expectations, high concentrations of ammonia and nitrite are not necessary for startup of an anammox or PdNA MBBR.},
}
@article {pmid35640508,
year = {2022},
author = {Chen, X and Li, F and Huo, P and Liu, J and Yang, L and Li, X and Wei, W and Ni, BJ},
title = {Influences of longitudinal gradients on methane-driven membrane biofilm reactor for complete nitrogen removal: A model-based investigation.},
journal = {Water research},
volume = {220},
number = {},
pages = {118665},
doi = {10.1016/j.watres.2022.118665},
pmid = {35640508},
issn = {1879-2448},
abstract = {Integrating anammox with denitrifying anaerobic methane oxidation (DAMO) in the membrane biofilm reactor (MBfR) is a promising technology capable of achieving complete nitrogen removal from wastewater. However, it remains unknown whether reactor configurations featuring longitudinal gradients parallel to the membrane surface would affect the performance of the CH4-driven MBfR. To this end, this work aims to study the impacts of longitudinal heterogeneity potentially present in the gas and liquid phases on a representative CH4-driven MBfR performing anammox/DAMO by applying the reported modified compartmental modeling approach. Through comparing the modeling results of different reactor configurations, this work not only offered important guidance for better design, operation and monitoring of the CH4-driven MBfR, but also revealed important implications for prospective related modeling research. The total nitrogen removal efficiency of the MBfR at non-excessive CH4 supply (e.g., surface loading of ≤0.064 g-COD m-2 d-1 in this work) was found to be insensitive to both longitudinal gradients in the liquid and gas phases. Comparatively, the longitudinal gradient in the liquid phase led to distinct longitudinal biomass stratification and therefore played an influential role in the effective CH4 utilization efficiency, which was also related to the extent of reactor compartmentation considered in modeling. When supplied with non-excessive CH4, the MBfR is recommended to be designed/operated with both the biofilm reactor and the membrane lumen as plug flow reactors (PFRs) with co-current flow of wastewater and CH4, which could mitigate dissolved CH4 discharge in the effluent. For the reactor configurations with the biofilm reactor designed/operated as a PFR, multi-spot sampling in the longitudinal direction is needed to obtain a correct representation of the microbial composition of the MBfR.},
}
@article {pmid35638465,
year = {2022},
author = {Lisac, A and Birsa, E and Podgornik, A},
title = {E. coli biofilm formation and its susceptibility towards T4 bacteriophages studied in a continuously operating mixing - tubular bioreactor system.},
journal = {Microbial biotechnology},
volume = {},
number = {},
pages = {},
doi = {10.1111/1751-7915.14079},
pmid = {35638465},
issn = {1751-7915},
support = {Interreg V-A Italy-Slovenia programme 2014-2020//European Regional Development Fund/ ; J7-2603//Javna Agencija za Raziskovalno Dejavnost RS/ ; P1-0153//Javna Agencija za Raziskovalno Dejavnost RS/ ; },
abstract = {A system consisting of a connected mixed and tubular bioreactor was designed to study bacterial biofilm formation and the effect of its exposure to bacteriophages under different experimental conditions. The bacterial biofilm inside silicone tubular bioreactor was formed during the continuous pumping of bacterial cells at a constant physiological state for 2 h and subsequent washing with a buffer for 24 h. Monitoring bacterial and bacteriophage concentration along the tubular bioreactor was performed via a piercing method. The presence of biofilm and planktonic cells was demonstrated by combining the piercing method, measurement of planktonic cell concentration at the tubular bioreactor outlet, and optical microscopy. The planktonic cell formation rate was found to be 8.95 × 10-3 h-1 and increased approximately four-fold (4×) after biofilm exposure to an LB medium. Exposure of bacterial biofilm to bacteriophages in the LB medium resulted in a rapid decrease of biofilm and planktonic cell concentration, to below the detection limit within < 2 h. When bacteriophages were supplied in the buffer, only a moderate decrease in the concentration of both bacterial cell types was observed. After biofilm washing with buffer to remove unadsorbed bacteriophages, its exposure to the LB medium (without bacteriophages) resulted in a rapid decrease in bacterial concentration: again below the detection limit in < 2 h.},
}
@article {pmid35638423,
year = {2022},
author = {Koehler, T and Wingender, J and Lueling, M and Meckelmann, SW and Telgheder, U and Schmitz, OJ},
title = {Characterization of the Extracellular Volatile Metabolome of Pseudomonas Aeruginosa Applying an in vitro Biofilm Model under Cystic Fibrosis-Like Conditions.},
journal = {Frontiers in bioscience (Landmark edition)},
volume = {27},
number = {5},
pages = {156},
doi = {10.31083/j.fbl2705156},
pmid = {35638423},
issn = {2768-6698},
abstract = {BACKGROUND: Cystic fibrosis (CF) is an autosomal recessive hereditary disease that leads to the production of thickened mucus in the lungs, favouring polymicrobial infections, such as chronic lung infections with the bacterial opportunistic pathogen Pseudomonas aeruginosa.<br><br>METHOD: A biofilm model in combination with an adapted sampling and GC-MS analysis method were applied to in vitro studies on different variables influencing the composition of the extracellular volatile metabolome of P. aeruginosa.<br><br>RESULTS: A significant influence on the metabolome could be demonstrated for the culture medium as well as the atmosphere during cultivation (aerobic or anaerobic). Furthermore, a significant influence of the mucoid (alginate-overproducing) phenotype of the bacterium on quantity and composition of volatile organic compounds could be observed. Based on the results a solid culture medium was developed to simulate the nutrient conditions in the lungs of a CF patient. The extracellular volatile metabolome of bacterial strains P. aeruginosa ATCC 10145, PAO1 and FRD1 was characterized under CF-like conditions.<br><br>CONCLUSIONS: Bacterial strain-dependent metabolites were identified. When P. aeruginosa PAO1 and FRD1 clinical isolates were compared, 36 metabolites showed significant variations in intensities. When the clinical isolates were compared with the reference strain (P. aeruginosa ATCC 10145), 28 metabolites (P. aeruginosa PAO1) and 70 metabolites (P. aeruginosa FRD1) were determined whose peaks showed significant deviation (p > 95%) in intensity. Furthermore, the bacterial strains could be differentiated from each other by means of two principal components.},
}
@article {pmid35636603,
year = {2022},
author = {Shitu, A and Zhang, Y and Danhassan, UA and Li, H and Tadda, MA and Ye, Z and Zhu, S},
title = {Synergistic effect of chitosan-based sludge aggregates CS@NGS inoculum accelerated the start-up of biofilm reactor treating aquaculture effluent: Insights into performance, microbial characteristics, and functional genes.},
journal = {Chemosphere},
volume = {},
number = {},
pages = {135097},
doi = {10.1016/j.chemosphere.2022.135097},
pmid = {35636603},
issn = {1879-1298},
abstract = {The moving bed bioreactor (MBBR) process has drawn more attention as a promising biological wastewater treatment process. Nevertheless, achieving quick start-up and microbial biofilm formation remains a significant challenge. Consequently, the present study investigated a novel chitosan-based natural sludge (CS@NGS) seeding strategy for the accelerated start-up of MBBR. Three identical bioreactors were employed; the first bioreactor was without sludge seed as the control (BR1), the second was inoculated only with sludge (BR2), and the third was inoculated with CS@NGS according to the proposed seeding method (BR3). All bioreactors were utilised to treat simulated recirculating aquaculture systems (RAS) effluent. Resultantly, the CS@NGS shortened the start-up period from over twenty to seven days due to the enhanced initial microbial adhesion and biofilm formation. Under optimal conditions, the ammonium removal in BR3 approached 100%, which was relatively higher than BR2 (96.35 ± 1.12%) and BR1 (92.56 ± 2.17%). Moreover, a low nitrite accumulation was exhibited in the effluents, approximately ≤0.03 mg L-1. The process performance correlated positively with core bacteria from the genera Nakamurella, Hyphomicrobium, Nitrospira, Paenarthrobacter, Rhodococcus, and Stenotrophobacter. The quantitative polymerase chain reaction (qPCR) results demonstrated that the CS@NGS enhanced the expressions of amoA, nxrB, nirK, nirS, narG, and napA nitrogen metabolism-related functional genes to varying degrees. The present study findings can assist the rapid start-up of aquaculture biofilters utilised to solve high nitrite and ammonia accumulation in recirculated water from industrial RAS.},
}
@article {pmid35636549,
year = {2022},
author = {Xue, Z and Zhang, T and Sun, Y and Yin, T and Cao, J and Fang, F and Feng, Q and Luo, J},
title = {Integrated moving bed biofilm reactor with partial denitrification-anammox for promoted nitrogen removal: Layered biofilm structure formation and symbiotic functional microbes.},
journal = {The Science of the total environment},
volume = {},
number = {},
pages = {156339},
doi = {10.1016/j.scitotenv.2022.156339},
pmid = {35636549},
issn = {1879-1026},
abstract = {Partial denitrification/anaerobic ammonia oxidation (anammox) (PD/A) is currently an advanced nitrogen removal process. This study developed a PD/A system in a moving bed biofilm reactor. Results showed that the nitrogen removal efficiency reached 76.60% with a COD/NO3-N of 2.0, and the contribution of anammox was 88.01%. Further analysis showed that the biocarriers could form layered pH and dissolved oxygen structures to promote the aggregation of different functional bacteria at various depths, thus stabilizing the coupled process. Microbial structure analysis showed that the abundance of Saccharimonadales, responsible for denitrification, increased from 0% to 36.27% between day 0 and day 120, while the abundance of Candidatus Jettenia, responsible for anammox, decreased from 10.41% to 2.20%. The synergistic effect of Saccharimonadales and Candidatus Jettenia enabled stable and efficient removal of nitrogen. This study proposed a novel configuration of the PD/A process and provided a theoretical basis for its promotion and application.},
}
@article {pmid35636093,
year = {2022},
author = {de Melo, ALF and Rossato, L and Barbosa, MDS and Palozi, RAC and Alfredo, TM and Antunes, KA and Eduvirgem, J and Ribeiro, SM and Simionatto, S},
title = {From the environment to the hospital: How plants can help to fight bacteria biofilm.},
journal = {Microbiological research},
volume = {261},
number = {},
pages = {127074},
doi = {10.1016/j.micres.2022.127074},
pmid = {35636093},
issn = {1618-0623},
abstract = {The emergence of resistance to antibiotics has become a global challenge as far as the control and treatment of nosocomial infections are concerned. Compared to the planktonic state, biofilms generally confer more resistance to antibiotics and may become a potential source of infection. Researchers are thus focused on developing novel drugs not as vulnerable as the current ones to bacterial resistance mechanisms and also able to target bacteria in biofilms. Natural products, especially those derived from plant sources, have substantiated significant medicinal activity with unique properties, making them perfect candidates for these much-needed therapeutics. Despite being a vast resource of antimicrobial molecules, limitations, including the low concentration of the extracted active compound and bioavailability, challenge the clinical application of medicinal plants to combat these infections. Nanotechnology through green synthesis is one of the strategies to explore the medicinal potential of plants. Research has established the promising outcome of this method in antibiofilm activity, in addition to improved drug delivery, targeting, and pharmacokinetic profiles. This review summarized the current knowledge on the potentialities of plant products as antibiotic adjuvants to restore the therapeutic activity of drugs. We also discussed biotechnological advances in medicinal plants to fight and eradicate biofilm-forming microorganisms.},
}
@article {pmid35635951,
year = {2022},
author = {Wang, L and Liu, L and Wang, X and Tan, Y and Duan, X and Zhang, C and Cheng, J and Xiong, Y and Jiang, G and Wang, J and Liao, X},
title = {Ruthenium(II) complexes targeting membrane as biofilm disruptors and resistance breakers in Staphylococcus aureus bacteria.},
journal = {European journal of medicinal chemistry},
volume = {238},
number = {},
pages = {114485},
doi = {10.1016/j.ejmech.2022.114485},
pmid = {35635951},
issn = {1768-3254},
abstract = {The development of ruthenium-based complexes or antimicrobial peptides are identified as a promising strategy for combating drug-resistant bacteria. In this work, four biphenyl-based antibacterial ruthenium complexes by targeting membrane integrity, which act as antimicrobial peptides mimics, were designed and synthesized. In vitro antimicrobial screening demonstrated that four complexes could absolutely inhibit the growth of Staphylococcus aureus (S. aureus) with MIC values ranging from 15.6 to 100 μg/mL. The most active complex Ru(Ⅱ)-1 (MIC = 15.6 μg/mL) could kill S. aureus through targeting the membrane integrity without detectably resistance frequencies. Further investigation including bacteria biofilm formation, hemolysin activity and checkerboard assay were performed as well. The results revealed that Ru(Ⅱ)-1 could inhibit the biofilm formation and α-hemolysis secretion in S. aureus at subinhibitory concentration. More interestingly, the combination use of Ru(Ⅱ)-1 and five traditional antibiotics showing synergistic effect. Finally, based on the mouse model of S. aureus skin infection, Ru(Ⅱ)-1 showed important antibacterial efficacy against S. aureus in vivo, and almost non-toxic against mouse tissue. Our study indicates that introducing membrane targeting ligands onto ruthenium complexes may be an underappreciated strategy for developing antibacterial agents.},
}
@article {pmid35634916,
year = {2022},
author = {Prasad, B and Shaikh, S and Saini, R and Wang, Q and Zadoo, S and Sadaphal, V and Greenberg, DE and Chopra, R},
title = {Quantifying the relationship between biofilm reduction and thermal tissue damage on metal implants exposed to alternating magnetic fields.},
journal = {International journal of hyperthermia : the official journal of European Society for Hyperthermic Oncology, North American Hyperthermia Group},
volume = {39},
number = {1},
pages = {713-724},
doi = {10.1080/02656736.2022.2065038},
pmid = {35634916},
issn = {1464-5157},
abstract = {AIM: Metal implant infections are a devastating problem due to the formation of biofilm which impairs the effectiveness of antibiotics and leads to surgical replacement as definitive treatment. Biofilm on metal implants can be reduced using heat generated by alternating magnetic fields (AMF). In this study, the relationship between implant surface biofilm reduction and surrounding tissue thermal damage during AMF exposure is investigated through numerical simulations.<br><br>METHODS: Mathematical models of biofilm reduction with heat were created based on in vitro experiments. Simulations were performed to predict the spatial and temporal heating on the implant surface and surrounding tissue when exposed to AMF.<br><br>RESULTS: The modeling results show that intermittent and slow heating can achieve biofilm reduction with a narrow zone of tissue damage around an implant of less than 3 mm. The results also emphasize that uniformity of implant heating is an extremely important factor impacting the effectiveness of biofilm reduction. For a knee implant, using a target temperature of 75 °C, an intermittent treatment strategy of 15 exposures (10 s to target temperature followed by cooldown) achieved a bacterial CFU reduction of 6-log10 across 25% of the implant surface with less than 3 mm of tissue damage. Alternatively, a single 60 s heating exposure to same temperature achieved a bacterial reduction of 6-log10 across 85% of the implant surface, but with 4 mm of tissue damage.<br><br>CONCLUSION: Overall, this study demonstrates that with uniform heating to temperatures above 70 °C, an implant surface can be largely reduced of biofilm, with only a few mm of surrounding tissue damage.},
}
@article {pmid35633295,
year = {2022},
author = {Grønseth, T and Ovchinnikov, KV and Carlsen, H and Benth, JŠ and Diep, DB and von Unge, M and Silvola, JT},
title = {Lugol's solution and Gentian violet eradicate methicillin-resistant Staphylococcus aureus biofilm in skin wound infections.},
journal = {International wound journal},
volume = {},
number = {},
pages = {},
doi = {10.1111/iwj.13846},
pmid = {35633295},
issn = {1742-481X},
support = {//Universitetet i Oslo/ ; },
abstract = {The study aimed to evaluate the antibacterial efficacy of Lugol's solution 5% and Gentian violet 1% against methicillin-resistant Staphylococcus aureus (MRSA) biofilm in vivo. The bactericidal efficacy for treatment of MRSA-biofilm skin wound infection was tested in a murine model. Luciferase-tagged S. aureus Xen31, a MRSA-strain derived from S. aureus ATCC-3359130, was used for infection. Wounds were made in the skin of mice and infected with MRSA. The mice were treated with Lugol's solution and Gentian violet. Application of the antimicrobial agents started 24 hours post infection and was repeated daily for five-days. The antimicrobial effect on the biofilm bacteria was evaluated by measuring bioluminescence from MRSA daily for seven-days. Lugol's solution and Gentian violet showed a significant reduction in luminescent signals from the first assessment day to all subsequent days (P < .001). Lugol's solution and Gentian violet effectively eradicated MRSA in biofilm in vivo and could be alternatives or in addition to topical antibiotics when MRSA-biofilm wound infection is suspected.},
}
@article {pmid35632937,
year = {2018},
author = {Namivandi-Zangeneh, R and Sadrearhami, Z and Bagheri, A and Sauvage-Nguyen, M and Ho, KKK and Kumar, N and Wong, EHH and Boyer, C},
title = {Nitric Oxide-Loaded Antimicrobial Polymer for the Synergistic Eradication of Bacterial Biofilm.},
journal = {ACS macro letters},
volume = {7},
number = {5},
pages = {592-597},
doi = {10.1021/acsmacrolett.8b00190},
pmid = {35632937},
issn = {2161-1653},
abstract = {Bacterial biofilms are often difficult to treat and represent the main cause of chronic and recurrent infections. In this study, we report the synthesis of a novel antimicrobial/antibiofilm polymer that consists of biocompatible oligoethylene glycol, hydrophobic ethylhexyl, cationic primary amine, and nitric oxide (NO)-releasing functional groups. The NO-loaded polymer has dual-action capability as it can release NO which triggers the dispersion of biofilm, whereas the polymer can induce bacteria cell death via membrane wall disruption. By functionalizing the polymers with NO, we observed a synergistic effect in biofilm dispersal, planktonic and biofilm killing activities against Pseudomonas aeruginosa. The NO-loaded polymer results in 80% reduction in biofilm biomass and kills >99.999% of planktonic and biofilm P. aeruginosa cells within 1 h of treatment at a polymer concentration of 64 μg mL-1. To achieve this synergistic effect, it is imperative that the NO donors and antimicrobial polymer exist as a single chemical entity, instead of a cocktail physical mixture of two individual components. The excellent antimicrobial/antibiofilm activity of this dual-action polymer suggests the advantages of combination therapy in combating bacterial biofilms.},
}
@article {pmid35632801,
year = {2022},
author = {Visnapuu, A and Van der Gucht, M and Wagemans, J and Lavigne, R},
title = {Deconstructing the Phage-Bacterial Biofilm Interaction as a Basis to Establish New Antibiofilm Strategies.},
journal = {Viruses},
volume = {14},
number = {5},
pages = {},
doi = {10.3390/v14051057},
pmid = {35632801},
issn = {1999-4915},
support = {1S44616N//Research Foundation - Flanders/ ; 1S43118N//Research Foundation - Flanders/ ; 819800/ERC_/European Research Council/International ; },
abstract = {The bacterial biofilm constitutes a complex environment that endows the bacterial community within with an ability to cope with biotic and abiotic stresses. Considering the interaction with bacterial viruses, these biofilms contain intrinsic defense mechanisms that protect against phage predation; these mechanisms are driven by physical, structural, and metabolic properties or governed by environment-induced mutations and bacterial diversity. In this regard, horizontal gene transfer can also be a driver of biofilm diversity and some (pro)phages can function as temporary allies in biofilm development. Conversely, as bacterial predators, phages have developed counter mechanisms to overcome the biofilm barrier. We highlight how these natural systems have previously inspired new antibiofilm design strategies, e.g., by utilizing exopolysaccharide degrading enzymes and peptidoglycan hydrolases. Next, we propose new potential approaches including phage-encoded DNases to target extracellular DNA, as well as phage-mediated inhibitors of cellular communication; these examples illustrate the relevance and importance of research aiming to elucidate novel antibiofilm mechanisms contained within the vast set of unknown ORFs from phages.},
}
@article {pmid35631633,
year = {2022},
author = {Lee, JH and Kim, YG and Park, S and Hu, L and Lee, J},
title = {Phytopigment Alizarin Inhibits Multispecies Biofilm Development by Cutibacterium acnes, Staphylococcus aureus, and Candida albicans.},
journal = {Pharmaceutics},
volume = {14},
number = {5},
pages = {},
doi = {10.3390/pharmaceutics14051047},
pmid = {35631633},
issn = {1999-4923},
support = {2021R1I1A3A04037486//National Research Foundation of Korea/ ; 2022R1C1C2006146//National Research Foundation of Korea/ ; 2021R1A2C1008368//National Research Foundation of Korea/ ; 2014R1A6A1031189//National Research Foundation of Korea/ ; },
abstract = {Acne vulgaris is a common chronic inflammatory skin disease involving Cutibacterium acnes with other skin commensals such as Staphylococcus aureus and Candida albicans in the anaerobic and lipid-rich conditions of pilosebaceous units. These microbes readily form multispecies biofilms that are tolerant of traditional antibiotics as well as host immune systems. The phytopigment alizarin was previously found to prevent biofilm formation by S. aureus and C. albicans strains under aerobic conditions. Hence, we hypothesized that alizarin might control C. acnes and multispecies biofilm development. We found that under anaerobic conditions, alizarin efficiently inhibited single biofilm formation and multispecies biofilm development by C. acnes, S. aureus, and C. albicans without inhibiting planktonic cell growth. Alizarin increased the hydrophilicities of S. aureus and C. albicans cells, decreased lipase production by S. aureus, diminished agglutination by C. acnes, and inhibited the aggregation of C. albicans cells. Furthermore, the co-administration of alizarin and antibiotics enhanced the antibiofilm efficacies of alizarin against C. acnes. A transcriptomic study showed that alizarin repressed the transcriptions of various biofilm-related genes such as lipase, hyaluronate lyase, adhesin/invasion-related, and virulence-related genes of C. acnes. Furthermore, alizarin at 100 µg/mL prevented C. acnes biofilm development on porcine skin. Our results show that alizarin inhibits multispecies biofilm development by acne-causing microbes and suggest it might be a useful agent for treating or preventing C. acnes-causing skin diseases.},
}
@article {pmid35631547,
year = {2022},
author = {Alzahrani, NM and Booq, RY and Aldossary, AM and Bakr, AA and Almughem, FA and Alfahad, AJ and Alsharif, WK and Jarallah, SJ and Alharbi, WS and Alsudir, SA and Alyamani, EJ and Tawfik, EA and Alshehri, AA},
title = {Liposome-Encapsulated Tobramycin and IDR-1018 Peptide Mediated Biofilm Disruption and Enhanced Antimicrobial Activity against Pseudomonas aeruginosa.},
journal = {Pharmaceutics},
volume = {14},
number = {5},
pages = {},
doi = {10.3390/pharmaceutics14050960},
pmid = {35631547},
issn = {1999-4923},
support = {20-0103 and 20-0051//National Industrial Development and Logistics Program/ ; },
abstract = {The inadequate eradication of pulmonary infections and chronic inflammation are significant complications in cystic fibrosis (CF) patients, who usually suffer from persistent and frequent lung infections caused by several pathogens, particularly Pseudomonas aeruginosa (P. aeruginosa). The ability of pathogenic microbes to protect themselves from biofilms leads to the development of an innate immune response and antibiotic resistance. In the present work, a reference bacterial strain of P. aeruginosa (PA01) and a multidrug-resistant isolate (MDR 7067) were used to explore the microbial susceptibility to three antibiotics (ceftazidime, imipenem, and tobramycin) and an anti-biofilm peptide (IDR-1018 peptide) using the minimum inhibition concentration (MIC). The most effective antibiotic was then encapsulated into liposomal nanoparticles and the IDR-1018 peptide with antibacterial activity, and the ability to disrupt the produced biofilm against PA01 and MDR 7067 was assessed. The MIC evaluation of the tobramycin antibacterial activity showed an insignificant effect on the liposomes loaded with tobramycin and liposomes encapsulating tobramycin and IDR-1018 against both P. aeruginosa strains to free tobramycin. Nevertheless, the biofilm formation was significantly reduced (p < 0.05) at concentrations of ≥4 μg/mL and ≤32 μg/mL for PA01 and ≤32 μg/mL for MDR 7067 when loading tobramycin into liposomes, with or without the anti-biofilm peptide compared to the free antibiotic, empty liposomes, and IDR-1018-loaded liposomes. A tobramycin concentration of ≤256 µg/mL was safe when exposed to a lung carcinoma cell line upon its encapsulation into the liposomal formulation. Tobramycin-loaded liposomes could be a potential candidate for treating lung-infected animal models owing to the high therapeutic efficacy and safety profile of this system compared to the free administration of the antibiotic.},
}
@article {pmid35631315,
year = {2022},
author = {Woelber, JP and Al-Ahmad, A and Alt, KW},
title = {On the Pathogenicity of the Oral Biofilm: A Critical Review from a Biological, Evolutionary, and Nutritional Point of View.},
journal = {Nutrients},
volume = {14},
number = {10},
pages = {},
doi = {10.3390/nu14102174},
pmid = {35631315},
issn = {2072-6643},
abstract = {Plaque control is one of the most recommended approaches in the prevention and therapy of caries and periodontal diseases. However, although most individuals in industrialized countries already perform daily oral hygiene, caries and periodontal diseases still are the most common diseases of mankind. This raises the question of whether plaque control is really a causative and effective approach to the prevention of these diseases. From an evolutionary, biological, and nutritional perspective, dental biofilms have to be considered a natural phenomenon, whereas several changes in human lifestyle factors during modern evolution are not "natural". These lifestyle factors include the modern "Western diet" (rich in sugar and saturated fats and low in micronutrients), smoking, sedentary behavior, and continuous stress. This review hypothesizes that not plaque itself but rather these modern, unnatural lifestyle factors are the real causes of the high prevalence of caries and periodontal diseases besides several other non-communicable diseases. Accordingly, applying evolutionary and lifestyle medicine in dentistry would offer a causative approach against oral and common diseases, which would not be possible with oral hygiene approaches used on their own.},
}
@article {pmid35631012,
year = {2022},
author = {Tokajuk, J and Deptuła, P and Chmielewska, SJ and Skłodowski, K and Mierzejewska, ŻA and Grądzka-Dahlke, M and Tołstoj, A and Daniluk, T and Paprocka, P and Savage, PB and Bucki, R},
title = {Ceragenin CSA-44 as a Means to Control the Formation of the Biofilm on the Surface of Tooth and Composite Fillings.},
journal = {Pathogens (Basel, Switzerland)},
volume = {11},
number = {5},
pages = {},
doi = {10.3390/pathogens11050491},
pmid = {35631012},
issn = {2076-0817},
support = {UMO-2018/31/B/NZ6/02476//National Science Center/ ; UDA- RPPD.01.01.00-20-001/15-00//Medical University of Bialystok as part of the RPOWP 2007-2013 481 funding, Priority I, Axis 1.1/ ; },
abstract = {Recurrent oral infections, as manifested by endodontic and periodontal disease, are often caused by Enterococcus faecalis (E. faecalis) and Candida albicans (C. albicans). Here, we assessed the anti-biofilm activity of ceragenin CSA-44 against these microbes growing as a biofilm in the presence of saliva on the surface of human teeth and dental composite (composite filling) subjected to mechanical stresses. Methods: Biofilm mass analysis was performed using crystal violet (CV) staining. The morphology, viscoelastic properties of the biofilm after CSA-44 treatment, and changes in the surface of the composite in response to biofilm presence were determined by AFM microscopy. Results: CSA-44 prevented biofilm formation and reduced the mass of biofilm formed by tested microorganisms on teeth and dental composite. Conclusion: The ability of CSA-44 to prevent the formation and to reduce the presence of established biofilm on tooth and composite filling suggests that it can serve as an agent in the development of new methods of combating oral pathogens and reduce the severity of oral infections.},
}
@article {pmid35630711,
year = {2022},
author = {Yu, T and Jiang, X and Xu, X and Jiang, C and Kang, R and Jiang, X},
title = {Andrographolide Inhibits Biofilm and Virulence in Listeria monocytogenes as a Quorum-Sensing Inhibitor.},
journal = {Molecules (Basel, Switzerland)},
volume = {27},
number = {10},
pages = {},
doi = {10.3390/molecules27103234},
pmid = {35630711},
issn = {1420-3049},
support = {20200148//the Cultivation Fund of the National Scientific Research Project of Henan Normal University/ ; 222300420470, 212300410220 and 202300410018//the Natural Science Foundation of Henan Province/ ; 22A180003//the Key Project of Natural Science of the Education Department of Henan Province/ ; 2021GGJS162//Henan Province Young Backbone Teacher Project/ ; },
abstract = {Listeria monocytogenes is a major foodborne pathogen that can cause listeriosis in humans and animals. Andrographolide is known as a natural antibiotic and exhibits good antibacterial activity. We aimed to investigate the effect of andrographolide on two quorum-sensing (QS) systems, LuxS/AI-2 and Agr/AIP of L. monocytogenes, as well as QS-controlled phenotypes in this study. Our results showed that neither luxS expression nor AI-2 production was affected by andrographolide. Nevertheless, andrographolide significantly reduced the expression levels of the agr genes and the activity of the agr promoter P2. Results from the crystal violet staining method, confocal laser scanning microscopy (CLSM), and field emission scanning electron microscopy (FE-SEM) demonstrated that andrographolide remarkably inhibited the biofilm-forming ability of L. monocytogenes 10403S. The preformed biofilms were eradicated when exposed to andrographolide, and reduced surviving cells were also observed in treated biofilms. L. monocytogenes treated with andrographolide exhibited decreased ability to secrete LLO and adhere to and invade Caco-2 cells. Therefore, andrographolide is a potential QS inhibitor by targeting the Agr QS system to reduce biofilm formation and virulence of L. monocytogenes.},
}
@article {pmid35630468,
year = {2022},
author = {Patel, M and Siddiqui, AJ and Ashraf, SA and Surti, M and Awadelkareem, AM and Snoussi, M and Hamadou, WS and Bardakci, F and Jamal, A and Jahan, S and Sachidanandan, M and Adnan, M},
title = {Lactiplantibacillus plantarum-Derived Biosurfactant Attenuates Quorum Sensing-Mediated Virulence and Biofilm Formation in Pseudomonas aeruginosa and Chromobacterium violaceum.},
journal = {Microorganisms},
volume = {10},
number = {5},
pages = {},
doi = {10.3390/microorganisms10051026},
pmid = {35630468},
issn = {2076-2607},
support = {RG-20094//University of Hail/ ; },
abstract = {Quorum sensing (QS) controls the expression of diverse biological traits in bacteria, including virulence factors. Any natural bioactive compound that disables the QS system is being considered as a potential strategy to prevent bacterial infection. Various biological activities of biosurfactants have been observed, including anti-QS effects. In the present study, we investigated the effectiveness of a biosurfactant derived from Lactiplantibacillus plantarum on QS-regulated virulence factors and biofilm formation in Pseudomonas aeruginosa and Chromobacterium violaceum. The structural analogues of the crude biosurfactant were identified using gas chromatography-mass spectrometry (GC-MS). Moreover, the inhibitory prospects of identified structural analogues were assessed with QS-associated CviR, LasA, and LasI ligands via in silico molecular docking analysis. An L. plantarum-derived biosurfactant showed a promising dose-dependent interference with the production of both violacein and acyl homoserine lactone (AHL) in C. violaceum. In P. aeruginosa, at a sub-MIC concentration (2.5 mg/mL), QS inhibitory activity was also demonstrated by reduction in pyocyanin (66.63%), total protease (60.95%), LasA (56.62%), and LasB elastase (51.33%) activity. The swarming motility and exopolysaccharide production were also significantly reduced in both C. violaceum (61.13%) and P. aeruginosa (53.11%). When compared with control, biofilm formation was also considerably reduced in C. violaceum (68.12%) and P. aeruginosa (59.80%). A GC-MS analysis confirmed that the crude biosurfactant derived from L. plantarum was a glycolipid type. Among all, n-hexadecanoic acid, oleic acid, and 1H-indene,1-hexadecyl-2,3-dihydro had a high affinity for CviR, LasI, and LasA, respectively. Thus, our findings suggest that the crude biosurfactant of L. plantarum can be used as a new anti-QS/antibiofilm agent against biofilm-associated pathogenesis, which warrants further investigation to uncover its therapeutic efficacy.},
}
@article {pmid35630375,
year = {2022},
author = {Soares, A and Gomes, LC and Monteiro, GA and Mergulhão, FJ},
title = {Hydrodynamic Effects on Biofilm Development and Recombinant Protein Expression.},
journal = {Microorganisms},
volume = {10},
number = {5},
pages = {},
doi = {10.3390/microorganisms10050931},
pmid = {35630375},
issn = {2076-2607},
support = {LA/P/0045/2020 (ALiCE), UIDB/00511/2020 and UIDP/00511/2020 (LEPABE)//FCT/MCTES (PIDDAC)/ ; PTDC/BII-BIO/29589/2017 - POCI-01-0145-FEDER-029589//FEDER funds through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) and by national funds (PIDDAC) through FCT/MCTES/ ; SFRH/BD/141614/2018; CEECIND/01700/2017//FCT/ ; },
abstract = {Hydrodynamics play an important role in the rate of cell attachment and nutrient and oxygen transfer, which can affect biofilm development and the level of recombinant protein production. In the present study, the effects of different flow conditions on the development of Escherichia coli biofilms and the expression of a model recombinant protein (enhanced green fluorescent protein, eGFP) were examined. Planktonic and biofilm cells were grown at two different flow rates in a recirculating flow cell system for 7 days: 255 and 128 L h-1 (corresponding to a Reynolds number of 4600 and 2300, respectively). The fluorometric analysis showed that the specific eGFP production was higher in biofilms than in planktonic cells under both hydrodynamic conditions (3-fold higher for 255 L h-1 and 2-fold higher for 128 L h-1). In the biofilm cells, the percentage of eGFP-expressing cells was on average 52% higher at a flow rate of 255 L h-1. Furthermore, a higher plasmid copy number (PCN) was obtained for the highest flow rate for both planktonic (244 PCN/cell versus 118 PCN/cell) and biofilm cells (43 PCN/cell versus 29 PCN/cell). The results suggested that higher flow velocities promoted eGFP expression in E. coli biofilms.},
}
@article {pmid35630353,
year = {2022},
author = {Shimizu, T and Aritoshi, T and Beatty, JT and Masuda, T},
title = {Persulfide-Responsive Transcription Factor SqrR Regulates Gene Transfer and Biofilm Formation via the Metabolic Modulation of Cyclic di-GMP in Rhodobacter capsulatus.},
journal = {Microorganisms},
volume = {10},
number = {5},
pages = {},
doi = {10.3390/microorganisms10050908},
pmid = {35630353},
issn = {2076-2607},
support = {JP18H03941//Japan Society for the Promotion of Science/ ; JP19H03241//Japan Society for the Promotion of Science/ ; JP20K06681//Japan Society for the Promotion of Science/ ; JP21K15038//Japan Society for the Promotion of Science/ ; JP21H05271//Japan Society for the Promotion of Science/ ; 20B004//Kurita Water and Environment Foundation/ ; 21K001//Kurita Water and Environment Foundation/ ; G-2019-2-010//Institute for Fermentation/ ; RGPIN 2018-03898//Natural Sciences and Engineering Research Council/ ; },
abstract = {Bacterial phage-like particles (gene transfer agents-GTAs) are widely employed as a crucial genetic vector in horizontal gene transfer. GTA-mediated gene transfer is induced in response to various stresses; however, regulatory mechanisms are poorly understood. We found that the persulfide-responsive transcription factor SqrR may repress the expression of several GTA-related genes in the photosynthetic bacterium Rhodobacter capsulatus. Here, we show that the sqrR deletion mutant (ΔsqrR) produces higher amounts of intra- and extracellular GTA and gene transfer activity than the wild type (WT). The transcript levels of GTA-related genes are also increased in ΔsqrR. In spite of the presumption that GTA-related genes are regulated in response to sulfide by SqrR, treatment with sulfide did not alter the transcript levels of these genes in the WT strain. Surprisingly, hydrogen peroxide increased the transcript levels of GTA-related genes in the WT, and this alteration was abolished in the ΔsqrR strain. Moreover, the absence of SqrR changed the intracellular cyclic dimeric GMP (c-di-GMP) levels, and the amount of c-di-GMP was correlated with GTA activity and biofilm formation. These results suggest that SqrR is related to the repression of GTA production and the activation of biofilm formation via control of the intracellular c-di-GMP levels.},
}
@article {pmid35630332,
year = {2022},
author = {Artini, M and Papa, R and Sapienza, F and Božović, M and Vrenna, G and Tuccio Guarna Assanti, V and Sabatino, M and Garzoli, S and Fiscarelli, EV and Ragno, R and Selan, L},
title = {Essential Oils Biofilm Modulation Activity and Machine Learning Analysis on Pseudomonas aeruginosa Isolates from Cystic Fibrosis Patients.},
journal = {Microorganisms},
volume = {10},
number = {5},
pages = {},
doi = {10.3390/microorganisms10050887},
pmid = {35630332},
issn = {2076-2607},
support = {RM118164361B425B//Sapienza University Rome/ ; RM11916B8876093E//Sapienza University Rome/ ; RM120172B8EB30C5//Sapienza University Rome/ ; RM12117A89F5B8BB//Sapienza University Rome/ ; RP120172A3B0262B//Sapienza University Rome/ ; AR12117A62B1D411//Sapienza University Rome/ ; },
abstract = {The opportunistic pathogen Pseudomonas aeruginosa is often involved in airway infections of cystic fibrosis (CF) patients. It persists in the hostile CF lung environment, inducing chronic infections due to the production of several virulence factors. In this regard, the ability to form a biofilm plays a pivotal role in CF airway colonization by P. aeruginosa. Bacterial virulence mitigation and bacterial cell adhesion hampering and/or biofilm reduced formation could represent a major target for the development of new therapeutic treatments for infection control. Essential oils (EOs) are being considered as a potential alternative in clinical settings for the prevention, treatment, and control of infections sustained by microbial biofilms. EOs are complex mixtures of different classes of organic compounds, usually used for the treatment of upper respiratory tract infections in traditional medicine. Recently, a wide series of EOs were investigated for their ability to modulate biofilm production by different pathogens comprising S. aureus, S. epidermidis, and P. aeruginosa strains. Machine learning (ML) algorithms were applied to develop classification models in order to suggest a possible antibiofilm action for each chemical component of the studied EOs. In the present study, we assessed the biofilm growth modulation exerted by 61 commercial EOs on a selected number of P. aeruginosa strains isolated from CF patients. Furthermore, ML has been used to shed light on the EO chemical components likely responsible for the positive or negative modulation of bacterial biofilm formation.},
}
@article {pmid35629935,
year = {2022},
author = {Fitzgerald, S and Furlong, C and Holland, L and Morrin, A},
title = {Multi-Strain and -Species Investigation of Volatile Metabolites Emitted from Planktonic and Biofilm Candida Cultures.},
journal = {Metabolites},
volume = {12},
number = {5},
pages = {},
doi = {10.3390/metabo12050432},
pmid = {35629935},
issn = {2218-1989},
support = {SFI/12/RC/2289_P2/SFI_/Science Foundation Ireland/Ireland ; },
abstract = {Candida parapsiliosis is a prevalent neonatal pathogen that attains its virulence through its strain-specific ability to form biofilms. The use of volatilomics, the profiling of volatile metabolites from microbes is a non-invasive, simple way to identify and classify microbes; it has shown great potential for pathogen identification. Although C. parapsiliosis is one of the most common clinical fungal pathogens, its volatilome has never been characterised. In this study, planktonic volatilomes of ten clinical strains of C. parapsilosis were analysed, along with a single strain of Candida albicans. Headspace-solid-phase microextraction coupled with gas chromatography-mass spectrometry were employed to analyse the samples. Species-, strain-, and media- influences on the fungal volatilomes were investigated. Twenty-four unique metabolites from the examined Candida spp. (22 from C. albicans; 18 from C. parapsilosis) were included in this study. Chemical classes detected across the samples included alcohols, fatty acid esters, acetates, thiols, sesquiterpenes, and nitrogen-containing compounds. C. albicans volatilomes were most clearly discriminated from C. parapsilosis based on the detection of unique sesquiterpene compounds. The effect of biofilm formation on the C. parapsilosis volatilomes was investigated for the first time by comparing volatilomes of a biofilm-positive strain and a biofilm-negative strain over time (0-48 h) using a novel sampling approach. Volatilomic shifts in the profiles of alcohols, ketones, acids, and acetates were observed specifically in the biofilm-forming samples and attributed to biofilm maturation. This study highlights species-specificity of Candida volatilomes, and also marks the clinical potential for volatilomics for non-invasively detecting fungal pathogens. Additionally, the range of biofilm-specificity across microbial volatilomes is potentially far-reaching, and therefore characterising these volatilomic changes in pathogenic fungal and bacterial biofilms could lead to novel opportunities for detecting severe infections early.},
}
@article {pmid35629533,
year = {2022},
author = {Khan, AS and Alshaia, A and AlDubayan, A and Alarifi, S and Alamri, A and Aldossary, H and Ahmed, SZ and Ateeq, IS and Hakeem, AS and Rehman, S},
title = {Preparation of Nano-Apatite Grafted Glass-Fiber-Reinforced Composites for Orthodontic Application: Mechanical and In Vitro Biofilm Analysis.},
journal = {Materials (Basel, Switzerland)},
volume = {15},
number = {10},
pages = {},
doi = {10.3390/ma15103504},
pmid = {35629533},
issn = {1996-1944},
abstract = {This study aimed to fabricate nano-hydroxyapatite (nHA) grafted/non-grafted E-glass-fiber-based (nHA/EG) and E-glass fiber (EG) orthodontic retainers and to compare their properties with commercially available retainers. Stainless-steel (SS) retainers and everStick Ortho (EST) were used as control groups. The retainers were evaluated with Raman spectroscopy and bonded to bovine teeth. The samples were fatigued under cyclic loading (120,000 cycles) followed by static load testing. The failure behavior was evaluated under an optical microscope and scanning electron microscope. The strain growth on the orthodontic retainers was assessed (48h and 168h) by an adhesion test using Staphylococcus aureus and Candida albicans. The characteristic peaks of resin and glass fibers were observed, and the debonding force results showed a significant difference among all of the groups. SS retainers showed the highest bonding force, whereas nHA/EG retainers showed a non-significant difference from EG and EST retainers. SS retainers' failure mode occurred mainly at the retainer-composite interface, while breakage occurred in glass-fiber-based retainers. The strains' adhesion to EST and EG was reduced with time. However, it was increased with nHA/EG. Fabrication of nHA/EG retainers was successfully achieved and showed better debonding force compared to other glass-fiber-based groups, whereas non-linear behavior was observed for the strains' adhesion.},
}
@article {pmid35627712,
year = {2022},
author = {Piletić, K and Kovač, B and Perčić, M and Žigon, J and Broznić, D and Karleuša, L and Lučić Blagojević, S and Oder, M and Gobin, I},
title = {Disinfecting Action of Gaseous Ozone on OXA-48-Producing Klebsiella pneumoniae Biofilm In Vitro.},
journal = {International journal of environmental research and public health},
volume = {19},
number = {10},
pages = {},
doi = {10.3390/ijerph19106177},
pmid = {35627712},
issn = {1660-4601},
support = {UNIRI18-171//University of Rijeka/ ; },
abstract = {Klebsiella pneumoniae is an emerging multidrug-resistant pathogen that can contaminate hospital surfaces in the form of a biofilm which is hard to remove with standard disinfectants. Because of biofilm resistance to conservative disinfectants, the application of new disinfection technologies is becoming more frequent. Ozone gas has antimicrobial activity but there is lack of data on its action against K. pneumoniae biofilm. The aim of this study was to investigate the effects and mechanisms of action of gaseous ozone on the OXA-48-procuding K. pneumoniae biofilm. A 24 h biofilm of K. pneumoniae formed on ceramic tiles was subsequently exposed to different concentrations of ozone during one and two hours to determine the optimal ozone concentration. Afterwards, the total bacteria count, total biomass and oxidative stress levels were monitored. A total of 25 ppm of gaseous ozone was determined to be optimal ozone concentration and caused reduction in total bacteria number in all strains of K. pneumoniae for 2.0 log10 CFU/cm2, followed by reduction in total biomass up to 88.15%. Reactive oxygen species levels significantly increased after the ozone treatment at 182% for the representative K. pneumoniae NCTC 13442 strain. Ozone gas in the concentration of 25 ppm caused significant biofilm reduction but did not completely eradicate the K. pneumoniae biofilm formed on ceramics. In conclusion, ozone gas has great potential to be used as an additional hygiene measure in joint combat against biofilm in hospital environments.},
}
@article {pmid35627252,
year = {2022},
author = {Shao, Y and Yin, C and Lv, F and Jiang, S and Wu, S and Han, Y and Xue, W and Ma, Y and Zheng, J and Zhan, Y and Ke, X and Lu, W and Lin, M and Shang, L and Yan, Y},
title = {The Sigma Factor AlgU Regulates Exopolysaccharide Production and Nitrogen-Fixing Biofilm Formation by Directly Activating the Transcription of pslA in Pseudomonas stutzeri A1501.},
journal = {Genes},
volume = {13},
number = {5},
pages = {},
doi = {10.3390/genes13050867},
pmid = {35627252},
issn = {2073-4425},
support = {2019YFA0904700; 2019ZX08010-002; 2016ZX08009003-002//Ministry of Science and Technology/ ; 31930004; 31770067;32150021;31230004//National Natural Science Foundation of China/ ; CAAS-ZDRW202009//Agricultural Science and Technology Innovation Program/ ; XDA28030201//Chinese Academy of Sciences/ ; 2019GXNSFBA245078//Guangxi natural science foundation/ ; },
abstract = {Pseudomonas stutzeri A1501, a plant-associated diazotrophic bacterium, prefers to conform to a nitrogen-fixing biofilm state under nitrogen-deficient conditions. The extracytoplasmic function (ECF) sigma factor AlgU is reported to play key roles in exopolysaccharide (EPS) production and biofilm formation in the Pseudomonas genus; however, the function of AlgU in P. stutzeri A1501 is still unclear. In this work, we mainly investigated the role of algU in EPS production, biofilm formation and nitrogenase activity in A1501. The algU mutant ΔalgU showed a dramatic decrease both in the EPS production and the biofilm formation capabilities. In addition, the biofilm-based nitrogenase activity was reduced by 81.4% in the ΔalgU mutant. The transcriptional level of pslA, a key Psl-like (a major EPS in A1501) synthesis-related gene, was almost completely inhibited in the algU mutant and was upregulated by 2.8-fold in the algU-overexpressing strain. A predicted AlgU-binding site was identified in the promoter region of pslA. The DNase I footprinting assays indicated that AlgU could directly bind to the pslA promoter, and β-galactosidase activity analysis further revealed mutations of the AlgU-binding boxes drastically reduced the transcriptional activity of the pslA promoter; moreover, we also demonstrated that AlgU was positively regulated by RpoN at the transcriptional level and negatively regulated by the RNA-binding protein RsmA at the posttranscriptional level. Taken together, these data suggest that AlgU promotes EPS production and nitrogen-fixing biofilm formation by directly activating the transcription of pslA, and the expression of AlgU is controlled by RpoN and RsmA at different regulatory levels.},
}
@article {pmid35627021,
year = {2022},
author = {Zhang, L and Meng, Y and Li, J and Yu, J and Mu, G and Tuo, Y},
title = {Lactiplantibacillus plantarum Y42 in Biofilm and Planktonic States Improves Intestinal Barrier Integrity and Modulates Gut Microbiota of Balb/c Mice.},
journal = {Foods (Basel, Switzerland)},
volume = {11},
number = {10},
pages = {},
doi = {10.3390/foods11101451},
pmid = {35627021},
issn = {2304-8158},
support = {32072193//National Natural Science Foundation of China/ ; },
abstract = {In our previous study, Lactiplantibacillus plantarum Y42 showed some potential probiotic functions and the ability to form biofilm. The aim of this study was to compare the similarities and differences in the probiotic and physiological traits of L. plantarum Y42 in the biofilm and planktonic states. L. plantarum Y42 in the biofilm state was proven to have higher survival after passing through mimic gastrointestinal fluid, as well as excellent adhesion properties on the HT-29 cell monolayers, than those in the planktonic state. The expression of tight junction proteins (TJ proteins) of HT-29 cell monolayers treated by L. plantarum Y42 in the planktonic state increased, while similar changes were not observed in the HT-29 cells treated by the strain in the biofilm state. Furthermore, Balb/c mice were orally administered L. plantarum Y42 in the biofilm and planktonic states, respectively. Compared to the planktonic state, the oral administration of L. plantarum Y42 in the biofilm state significantly boosted IgA levels and improved the immunity of the mice. High-throughput sequencing showed that the diversity and structure of the intestinal flora of the mice were changed after the oral administration of L. plantarum Y42, including the up-regulated relative abundance of Lactobacillus in the intestinal tract of the mice, with no difference between the biofilm and planktonic states. Moreover, oral administration of L. plantarum Y42 in biofilm and planktonic states reduced the release of proinflammatory factors, to a certain extent, in the serum of the mice. The similarities and differences in the probiotic and physiological properties of L. plantarum Y42 in the biofilm and planktonic states can be contributed to the reasonable application of the strain.},
}
@article {pmid35625936,
year = {2022},
author = {Wu, YF and Lin, YC and Yang, HW and Cheng, NC and Cheng, CM},
title = {Point-of-Care Wound Blotting with Alcian Blue Grading versus Fluorescence Imaging for Biofilm Detection and Predicting 90-Day Healing Outcomes.},
journal = {Biomedicines},
volume = {10},
number = {5},
pages = {},
doi = {10.3390/biomedicines10051200},
pmid = {35625936},
issn = {2227-9059},
support = {110-BIH028//National Tsing Hua University-National Taiwan University BioMedical Park Hospital Collabora-tion Project/ ; 110-HCH073//National Tsing Hua University-National Taiwan University Hospital Hsin-Chu Branch Collaboration Project/ ; MOST 110-2222-E-002 -013-//Taiwan's Ministry of Science and Technology/ ; },
abstract = {Biofilm infection has been identified as a crucial factor of the pathogenesis of chronic wound, but wound biofilm diagnosis remains as an unmet clinical need. We previously proposed a modified wound blotting technique using Alcian blue staining for biofilm detection that was characterized as being non-invasive, time-saving, non-expansive, and informative for biofilm distribution. In this study, we adapted a novel Alcian blue grading method as the severity of biofilm infection for the wound blotting technique and compared its biofilm detection efficacy with MolecuLight i:X- a point-of-care florescence imaging device to detect bacteria and biofilm in wounds. Moreover, their predictive value of complete wound healing at 90 days was analyzed. When validated with wound culture results in the 53 enrolled subjects with chronic wounds, the modified wound blotting method showed a strong association with wound culture, while MolecuLight i:X only exhibited a weak association. In predicting 90-day wound outcomes, the modified wound blotting method showed a strong association (Kendall's tau value = 0.563, p < 0.001), and the wound culture showed a moderate association (Spearman's rho = 0.535, p < 0.001), but MolecuLight i:X exhibited no significant association (p = 0.184). In this study, modified wound blotting with the Alcian blue grading method showed superior value to MolecuLight i:X both in biofilm detection and predictive validity in 90-day wound-healing outcomes.},
}
@article {pmid35625693,
year = {2022},
author = {Solarte, DLG and Rau, SJ and Hellwig, E and Vach, K and Al-Ahmad, A},
title = {Antimicrobial Behavior and Cytotoxicity of Indocyanine Green in Combination with Visible Light and Water-Filtered Infrared A Radiation against Periodontal Bacteria and Subgingival Biofilm.},
journal = {Biomedicines},
volume = {10},
number = {5},
pages = {},
doi = {10.3390/biomedicines10050956},
pmid = {35625693},
issn = {2227-9059},
support = {ICG//Dr. Braun Science Foundation/ ; AL 1179/4-1//Deutsche Forschungsgemeinschaft/ ; },
abstract = {The widespread increase of antibiotic resistance highlights the need for alternative treatments such as antimicrobial photodynamic therapy (aPDT). This study aimed to evaluate the antimicrobial behavior and cytotoxicity of aPDT with indocyanine green (ICG) in combination with visible light (Vis) and water-filtered infrared A (wIRA). Representative periodontal bacteria (Parvimonas micra, Atopobium riame, Slackia exigua, Actinomyces naeslundii, Porphyromonas gingivalis, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, and Prevotella nigrescens) and subgingival in situ biofilms from periodontal patients were treated with aPDT for 5 min. ICG was used at different concentrations (50-500 µg/mL) and the number of viable cells was determined in colony forming units (CFU). Untreated negative controls and 0.2% chlorhexidine as a positive control were also prepared. The cytotoxicity test on human keratinocytes in vitro was analyzed with the AlamarBlue assay after 5, 10, and 20 min, with four ICG concentrations, and at two temperatures (room temperature and 37 °C). The tested periodontal pathogens treated with aPDT were eliminated in a range between 1.2 and 6.7 log10 CFU, except for A. naeslundii, which was killed at a lower range. The subgingival biofilm treated with aPDT expressed significant differences to the untreated controls except for at 300 µg/mL ICG concentration. The cytotoxicity was directly related to the concentration of ICG and irradiation time. These observations raise questions concerning the use of this specific aPDT as an adjuvant to periodontal treatments due to its possible toxicity towards human gingival cells.},
}
@article {pmid35625332,
year = {2022},
author = {Auer, DL and Mao, X and Anderson, AC and Muehler, D and Wittmer, A and von Ohle, C and Wolff, D and Frese, C and Hiller, KA and Maisch, T and Buchalla, W and Hellwig, E and Al-Ahmad, A and Cieplik, F},
title = {Phenotypic Adaptation to Antiseptics and Effects on Biofilm Formation Capacity and Antibiotic Resistance in Clinical Isolates of Early Colonizers in Dental Plaque.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {11},
number = {5},
pages = {},
doi = {10.3390/antibiotics11050688},
pmid = {35625332},
issn = {2079-6382},
support = {CI 263/3-1//Deutsche Forschungsgemeinschaft/ ; AL 1179/4-1//Deutsche Forschungsgemeinschaft/ ; },
abstract = {Despite the wide-spread use of antiseptics in dental practice and oral care products, there is little public awareness of potential risks associated with antiseptic resistance and potentially concomitant cross-resistance. Therefore, the aim of this study was to investigate potential phenotypic adaptation in 177 clinical isolates of early colonizers of dental plaque (Streptococcus, Actinomyces, Rothia and Veillonella spp.) upon repeated exposure to subinhibitory concentrations of chlorhexidine digluconate (CHX) or cetylpyridinium chloride (CPC) over 10 passages using a modified microdilution method. Stability of phenotypic adaptation was re-evaluated after culture in antiseptic-free nutrient broth for 24 or 72 h. Strains showing 8-fold minimal inhibitory concentration (MIC)-increase were further examined regarding their biofilm formation capacity, phenotypic antibiotic resistance and presence of antibiotic resistance genes (ARGs). Eight-fold MIC-increases to CHX were detected in four Streptococcus isolates. These strains mostly exhibited significantly increased biofilm formation capacity compared to their respective wild-type strains. Phenotypic antibiotic resistance was detected to tetracycline and erythromycin, consistent with the detected ARGs. In conclusion, this study shows that clinical isolates of early colonizers of dental plaque can phenotypically adapt toward antiseptics such as CHX upon repeated exposure. The underlying mechanisms at genomic and transcriptomic levels need to be investigated in future studies.},
}
@article {pmid35625312,
year = {2022},
author = {Mostafa, EM and Abdelgawad, MA and Musa, A and Alotaibi, NH and Elkomy, MH and Ghoneim, MM and Badawy, MSEM and Taha, MN and Hassan, HM and Hamed, AA},
title = {Chitosan Silver and Gold Nanoparticle Formation Using Endophytic Fungi as Powerful Antimicrobial and Anti-Biofilm Potentialities.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {11},
number = {5},
pages = {},
doi = {10.3390/antibiotics11050668},
pmid = {35625312},
issn = {2079-6382},
abstract = {Nanotechnology is emerging as a new technology with encouraging innovations. Global antibiotic use has grown enormously, with antibiotic resistance increasing by about 80 percent. In view of this alarming situation, intensive research has been carried out into biogenic nanoparticles and their antibacterial, antifungal, and antitumor activities. Many methods are available to enhance stability and dispersion via peroration of conjugate with a polymer, such as chitosan, and other bioactive natural products. Two marine fungi were isolated and identified as Aspergillus sp. and Alternaria sp. via sequencing of the 16S rRNA gene. In this work, these strains were used to form the conjugation of biogenic silver nanoparticles (AgNPs) from Aspergillus sp. Silv2 extract and gold nanoparticles (AuNPs) from Alternaria sp. Gol2 extracts with chitosan to prepare chitosan-AgNPs and chitosan-AuNP conjugates. A variety of imaging and analytical methods, such as UV-vis, X-ray powder diffraction (XRD), FTIR spectroscopy, transmission electron microscopy (TEM), and scanning electron microscopy (SEM) were utilized to characterize biogenic nanoparticles and conjugates. The biosynthesized Ag and Au nanoparticles along with the prepared conjugates were evaluated for their antimicrobial effects on Gram-negative and Gram-positive bacterial isolates, including Escherichia coli and Staphylococcus aureus. Both chitosan-AgNP and AuNP showed powerful antimicrobial activities compared to the control. On the other hand, chitosan-AgNP conjugation had better antibacterial ctivity than chitosan-AuNPs, which exhibited moderate activity against S. aureus and very low activity against E. coli. Furthermore, the antibiofilm potentials of the prepared conjugates were tested against four biofilm-forming bacteria, including P. aeruginosa, B. subtilis, E. coli, and S. aureus. The obtained results indicate that the chitosan-AgNP showed a promising anti-biofilm activities on all strains, especially S. aureus, while chitosan-AuNP conjugates showed moderate anti-biofilm against B. subtilis and weak activities against the other three strains. These results showed the superiority of chitosan-AgNP as a promising antibacterial as well as biofilm formation inhibitors.},
}
@article {pmid35625268,
year = {2022},
author = {Doan, TH and Bernet-Camard, MF and Hoÿs, S and Janoir, C and Péchiné, S},
title = {Impact of Subinhibitory Concentrations of Metronidazole on Morphology, Motility, Biofilm Formation and Colonization of Clostridioides difficile.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {11},
number = {5},
pages = {},
doi = {10.3390/antibiotics11050624},
pmid = {35625268},
issn = {2079-6382},
abstract = {Clostridioides difficile infection (CDI) is the primary cause of health-care-associated infectious diarrhea. Treatment requires mostly specific antibiotics such as metronidazole (MTZ), vancomycin or fidaxomicin. However, approximately 20% of treated patients experience recurrences. Treatment with MTZ is complicated by reduced susceptibility to this molecule, which could result in high failure and recurrence rates. However, the mechanism remains unclear. In this study, we investigated the impact of subinhibitory concentrations of MTZ on morphology, motility, biofilm formation, bacterial adherence to the intestinal Caco-2/TC7 differentiated monolayers, and colonization in monoxenic and conventional mouse models of two C. difficile strains (VPI 10463 and CD17-146), showing different susceptibility profiles to MTZ. Our results revealed that in addition to the inhibition of motility and the downregulation of flagellar genes for both strains, sub-inhibitory concentrations of MTZ induced various in vitro phenotypes for the strain CD17-146 exhibiting a reduced susceptibility to this antibiotic: elongated morphology, enhanced biofilm production and increased adherence to Caco-2/TC7 cells. Weak doses of MTZ induced higher level of colonization in the conventional mouse model and a trend to thicker 3-D structures entrapping bacteria in monoxenic mouse model. Thus, sub-inhibitory concentrations of MTZ can have a wide range of physiological effects on bacteria, which may contribute to their persistence after treatment.},
}
@article {pmid35625242,
year = {2022},
author = {Kim, D and Kim, KY},
title = {Pectolinarin Inhibits the Bacterial Biofilm Formation and Thereby Reduces Bacterial Pathogenicity.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {11},
number = {5},
pages = {},
doi = {10.3390/antibiotics11050598},
pmid = {35625242},
issn = {2079-6382},
support = {GRRC-kyunghee2020(B04)//Gyeonggi do Regionaol Research center/ ; },
abstract = {Bacterial biofilms are a growing problem as it is a major cause of nosocomial infection from urinary catheters to chronic tissue infections and provide resistance to a variety of antibiotics and the host's immune system. The effect of pectolinarin on the biofilm formation in Enterococcus faecalis, Enterococcus faecium, Escherichia coli, Streptococcus mutans, Streptococcus sobrinus, Staphylococcus aureus, Pseudomonas aeruginosa, Cutibacterium acnes, and Porphyromonas gingivalis was studied in TSBg (tryptic soy broth supplemented with 1% glucose). Pectolinarin inhibited biofilm formation of E. faecalis (IC50 = 0.39 μg/mL), E. faecium (IC50 = 0.19 μg/mL), E. coli (IC50 = 0.25 μg/mL), S. mutans (IC50 = 1.2 μg/mL), S. sobrinus (IC50 = 1.4 μg/mL), S. aureus (IC50 = 0.39 μg/mL), P. aeruginosa (IC50 = 0.9 μg/mL), P. acnes (IC50 = 12.5 μg/mL), and P. gingivalis (IC50 = 9.0 μg/mL) without inhibiting the bacterial growth. Pectolinarin also showed increased susceptibility of antibacterial activity with commercially available antibiotics including ampicillin, vancomycin, streptomycin, and oxytetracyclin against E. faecalis and E. faecium. Finally, pectolinarin dose-dependently reduced the expression of genes including cytolysin genes (cylLS, cylR2 and cylM), quorum sensing (QS) genes (fsrB, fsrC, gelE, ebpA, ebpB, acm, scm and bps), and biofilm virulence genes (esp) of E. faecalis and E. faecium. Pectolinarin reduced the bacterial biofilm formation, activated the antibacterial susceptibility, and reduced the bacterial adherence. These results suggest that bacterial biofilm formation is a good target to develop the antibacterial agents against biofilm-related infections.},
}
@article {pmid35625233,
year = {2022},
author = {Portell-Buj, E and González-Criollo, C and López-Gavín, A and Fernández-Pittol, M and Busquets, MA and Estelrich, J and Garrigó, M and Rubio, M and Tudó, G and Gonzalez-Martin, J},
title = {Activity of Antibiotics and Potential Antibiofilm Agents against Biofilm-Producing Mycobacterium avium-intracellulare Complex Causing Chronic Pulmonary Infections.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {11},
number = {5},
pages = {},
doi = {10.3390/antibiotics11050589},
pmid = {35625233},
issn = {2079-6382},
support = {PI16/01047//Instituto de Salud Carlos III/ ; 201816-10//Fundació La Marató TV3/ ; 937-2019//Sociedad Española de Neumología y Cirugía Torácica/ ; },
abstract = {Nontuberculous mycobacteria (NTM) cause lung infections in patients with underlying pulmonary diseases (PD). The Mycobacteriumavium-intracellulare complex (MAC) is the most frequently involved NTM. The MAC-PD treatment is based on the administration of several antibiotics for long periods of time. Nonetheless, treatment outcomes remain very poor. Among the factors involved is the ability of MAC isolates to form biofilm. The aim of the study was to assess the in vitro activity of different antibiotics and potential antibiofilm agents (PAAs) against MAC biofilm. Four antibiotics and six PAAs, alone and/or in combination, were tested against planktonic forms of 11 MAC clinical isolates. Biofilm was produced after 4 weeks of incubation and analyzed with the crystal violet assay. The antibiotics and PAAs were tested by measuring the absorbance (minimum biofilm inhibition concentrations, MBICs) and by performing subcultures (minimum biofilm eradication concentrations, MBECs). The clarithromycin/amikacin and clarithromycin/ethambutol combinations were synergistic, decreasing the MBECs values compared to the individual antibiotics. The amikacin/moxifloxacin combination showed indifference. The MBIC values decreased significantly when PAAs were added to the antibiotic combinations. These results suggest that antibiotic combinations should be further studied to establish their antibiofilm activity. Moreover, PAAs could act against the biofilm matrix, facilitating the activity of antibiotics.},
}
@article {pmid35625217,
year = {2022},
author = {Ashrit, P and Sadanandan, B and Shetty, K and Vaniyamparambath, V},
title = {Polymicrobial Biofilm Dynamics of Multidrug-Resistant Candida albicans and Ampicillin-Resistant Escherichia coli and Antimicrobial Inhibition by Aqueous Garlic Extract.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {11},
number = {5},
pages = {},
doi = {10.3390/antibiotics11050573},
pmid = {35625217},
issn = {2079-6382},
support = {SR/WOS-A/LS-481/2013 (G)//Department of Science and Technology/ ; },
abstract = {The polymicrobial biofilm of C. albicans with E. coli exhibits a dynamic interspecies interaction and is refractory to conventional antimicrobials. In this study, a high biofilm-forming multidrug-resistant strain of C. albicans overcomes inhibition by E. coli in a 24 h coculture. However, following treatment with whole Aqueous Garlic Extract (AGE), these individual biofilms of multidrug-resistant C. albicans M-207 and Ampicillin-resistant Escherichia coli ATCC 39936 and their polymicrobial biofilm were prevented, as evidenced by biochemical and structural characterization. This study advances the antimicrobial potential of AGE to inhibit drug-resistant C. albicans and bacterial-associated polymicrobial biofilms, suggesting the potential for effective combinatorial and synergistic antimicrobial designs with minimal side effects.},
}
@article {pmid35625202,
year = {2022},
author = {Castro, J and Sousa, LGV and França, Â and Podpera Tisakova, L and Corsini, L and Cerca, N},
title = {Exploiting the Anti-Biofilm Effect of the Engineered Phage Endolysin PM-477 to Disrupt In Vitro Single- and Dual-Species Biofilms of Vaginal Pathogens Associated with Bacterial Vaginosis.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {11},
number = {5},
pages = {},
doi = {10.3390/antibiotics11050558},
pmid = {35625202},
issn = {2079-6382},
support = {UIDB/04469/2020//Fundação para a Ciência e Tecnologia/ ; },
abstract = {Bacterial vaginosis (BV) is the most frequent vaginal infection in women of reproductive age. It is caused by the overgrowth of anaerobic vaginal pathogens, such as Gardnerella vaginalis, Fannyhessea vaginae, and Prevotella bivia, which are vaginal pathogens detected during the early stages of incident BV and have been found to form multi-species biofilms. Treatment of biofilm-associated infections, such as BV, is challenging. In this study, we tested the role of an investigational engineered phage endolysin, PM-477, in the eradication of dual-species biofilms composed of G. vaginalis-F. vaginae or G. vaginalis-P. bivia. Single-species biofilms formed by these species were also analysed as controls. The effect of PM-477 on biomass and culturability of single- and dual-species biofilms was assessed in vitro using a microtiter plate assay, epifluorescence microscopy, confocal laser scanning microscopy, and quantitative PCR. The results showed that PM-477 was particularly effective in the disruption and reduction of culturability of G. vaginalis biofilms. In dual-species biofilms, PM-477 exhibited lower efficiency but was still able to selectively and significantly eliminate G. vaginalis. Since polymicrobial interactions have been shown to strongly affect the activity of various antibiotics, the activity of PM-477 in dual-species biofilms is a potentially promising result that should be further explored, aiming to completely eradicate multi-species biofilms associated with BV.},
}
@article {pmid35624548,
year = {2022},
author = {Jyväsjärvi, J and Rajakallio, M and Brüsecke, J and Huttunen, KL and Huusko, A and Muotka, T and Taipale, SJ},
title = {Dark matters - contrasting responses of stream biofilm to browning and loss of riparian shading.},
journal = {Global change biology},
volume = {},
number = {},
pages = {},
doi = {10.1111/gcb.16279},
pmid = {35624548},
issn = {1365-2486},
abstract = {Concentrations of terrestrial-derived dissolved organic carbon (DOC) in freshwater ecosystems have increased consistently, causing freshwater browning. The mechanisms behind browning are complex, but in forestry-intensive regions browning is accelerated by land drainage. Forestry actions in streamside riparian forests alter canopy shading, which together with browning is expected to exert a complex and largely unpredictable control over key ecosystem functions. We conducted a stream mesocosm experiment with three levels of browning (ambient vs. moderate vs. high, with 2.7 and 5.5-fold increase, respectively, in absorbance) crossed with two levels of riparian shading (70% light reduction vs. open canopy) to explore the individual and combined effects of browning and loss of shading on the quantity (algal biomass) and nutritional quality (polyunsaturated fatty acid and sterol content) of the periphytic biofilm. We also conducted a field survey of differently colored (4.7 to 26.2 mg DOC L-1) streams to provide a 'reality check' for our experimental findings. Browning reduced greatly the algal biomass, suppressed the availability of essential polyunsaturated fatty acids, especially eicosapentaenoic acid (EPA), and sterols, but increased the availability of terrestrial-derived long-chain saturated fatty acids (LSAFA). In contrast, loss of shading increased primary productivity, which resulted in elevated sterol and EPA content of the biofilm. The field survey largely repeated the same pattern: biofilm nutritional quality decreased significantly with increasing DOC, as indicated particularly by a decrease of the ω-3:ω-6 ratio and increase in LSAFA content. Algal biomass, in contrast, was mainly controlled by dissolved inorganic nitrogen (DIN) concentration, while DOC concentration was of minor importance. The ongoing browning process is inducing a dramatic reduction in the nutritional quality of the stream biofilm. Such degradation of the major high-quality food source available for stream consumers may reduce the trophic transfer efficiency in stream ecosystems, potentially extending across the stream-forest ecotone.},
}
@article {pmid35623782,
year = {2022},
author = {Caniglia, G and Sportelli, MC and Heinzmann, A and Picca, RA and Valentini, A and Barth, H and Mizaikoff, B and Cioffi, N and Kranz, C},
title = {Silver-fluoropolymer (Ag-CFX) films: Kinetic study of silver release, and spectroscopic-microscopic insight into the inhibition of P. fluorescens biofilm formation.},
journal = {Analytica chimica acta},
volume = {1212},
number = {},
pages = {339892},
doi = {10.1016/j.aca.2022.339892},
pmid = {35623782},
issn = {1873-4324},
abstract = {Silver-fluoropolymer (Ag-CFX) composed of encapsulated bioactive nanophases within a thin polymer coating are promising antimicrobial films with excellent bioactivity. In this contribution, we report on Ag-CFX thin films obtained by ion beam co-sputtering, accurately tuning film thickness, and inorganic loading. The Ag-CFX films were characterized by spectroscopic and scanning probe microscopy techniques with respect to composition and swelling behavior. Next to electrothermal atomic absorption spectroscopy (ETAAS) studies, scanning electrochemical microscopy (SECM) experiments in combination with anodic stripping voltammetry (ASV) were carried out to study the release mechanism of silver(I) from the embedded silver nanoparticles (AgNPs). Silver(I) concentration profiles at the Ag-CFX films in contact with water resulted in a release of 1310 ± 50 μg L-1 (n = 3) after 27 h of immersion and corresponded well to the swelling of the films. The antimicrobial properties towards biofilm formation of P. fluorescens were studied by attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy during a period of 48 h. The obtained IR data revealed biofilm inhibition due to the presence of the antimicrobial layer but also indicated potential surface re-colonization after 30 h of contact with the bacteria-containing solution. The occurrence of cyclic changes in the characteristic IR bands correlated with apparent stress of bottom-layered bacteria, along with re-colonization on top of dead biomass, indicative of potential cannibalism events.},
}
@article {pmid35623775,
year = {2022},
author = {Ge, Y and Ge, Z and Zheng, J and Sheng, X and He, L},
title = {Biofilm-overproducing Bacillus subtilis B12ΔYwcc decreases Cd uptake in Chinese cabbage through increasing Cd-immobilizing related gene abundance and root surface colonization.},
journal = {Journal of environmental sciences (China)},
volume = {120},
number = {},
pages = {84-93},
doi = {10.1016/j.jes.2022.01.016},
pmid = {35623775},
issn = {1001-0742},
abstract = {Biofilm-producing bacteria can decrease Cd uptake in vegetables, but mechanisms underlying this effect are poorly characterized. In this study, two mutant strains B12ΔYwcc and B12ΔSlrR were constructed from a biofilm-producing Bacillus subtilis strain B12. Then, the impacts of strain B12 and its high biofilm-producing mutant strain B12ΔYwcc and low biofilm-producing mutant strain B12ΔSlrR on Cd availability and uptake in Chinese cabbage and the related mechanisms were investigated in the Cd-polluted soil. Strain B12 and its mutants B12ΔYwcc and B12ΔSlrR increased the dry biomasses of edible tissues by 54%-130% compared with the controls. Strain B12 and its mutant B12ΔYwcc reduced the soil available Cd content by 36%-50% and root and edible tissue Cd contents by 23%-50% compared with the controls. Furthermore, the mutant strain B12ΔYwcc reduced the edible tissue Cd content by 40% and increased the polysaccharide content by 23%, invertase activity by 139%, and gene copies of the cumA by 4.5-fold, epsA by 7.1-fold, and cadA by 4.3-fold, which were involved in Cd adsorption in the rhizosphere soils, respectively, compared with strain B12. The polysaccharide content and cumA, epsA, and cadA gene copy numbers showed significantly reverse correlations with the available Cd content. Notably, the mutant strain B12ΔYwcc showed better ability to colonize the vegetable root surface than strain B12. These findings demonstrated that the biofilm-overproducing mutant strain B12ΔYwcc increased the polysaccharide production and Cd-immobilizing related cumA, epsA, and cadA gene copies, resulting in lower Cd availability and accumulation in Chinese cabbage in the Cd-polluted soil.},
}
@article {pmid35623607,
year = {2022},
author = {Wang, C and Lin, Q and Yao, Y and Xu, R and Wu, X and Meng, F},
title = {Achieving simultaneous nitrification, denitrification, and phosphorus removal in pilot-scale flow-through biofilm reactor with low dissolved oxygen concentrations: Performance and mechanisms.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {127373},
doi = {10.1016/j.biortech.2022.127373},
pmid = {35623607},
issn = {1873-2976},
abstract = {In this pilot-scale study, a flow-through biofilm reactor (FTBR) was investigated for municipal wastewater treatment. The removal efficiencies for ammonium, total nitrogen, total phosphorus, and chemical oxygen demand were 87.2 ± 17.9%, 61.1 ± 13.9%, 83.5 ± 11.9%, and 92.6 ± 1.7%, respectively, at low dissolved oxygen concentrations (averaged at 0.59 mg/L), indicating the feasibility and robustness of the FTBR for a simultaneous nitrification, denitrification, and phosphorous removal (SNDPR) process. The co-occurrence network of bacteria in the dynamic biofilm was complex, with equivalent bacterial cooperation and competition. Nevertheless, the bacterial interactions in the suspended sludge were mainly cooperative. The presence of dynamic biofilms increased bacterial diversity by creating niche differentiation, which enriched keystone species closely related to nutrient removal. Overall, this study provides a novel FTBR-based SNDPR process and reveals the ecological mechanisms responsible for nutrient removal.},
}
@article {pmid35623093,
year = {2022},
author = {Li, W and Siddique, MS and Graham, N and Yu, W},
title = {Influence of Temperature on Biofilm Formation Mechanisms Using a Gravity-Driven Membrane (GDM) System: Insights from Microbial Community Structures and Metabolomics.},
journal = {Environmental science &amp; technology},
volume = {},
number = {},
pages = {},
doi = {10.1021/acs.est.2c01243},
pmid = {35623093},
issn = {1520-5851},
abstract = {A biofilm has a significant effect on water treatment processes. Currently, there is a lack of knowledge about the effect of temperature on the biofilm structure in water treatment processes. In this study, a gravity-driven membrane ultrafiltration system was operated with river feedwater at two temperatures ("low", 4 °C; "high", 25 °C) to explore the biofilm structure and transformation mechanism. The results showed that the difference in dissolved oxygen concentration might be one of the main factors regulating the structural components of the biofilm. A denser biofilm formation and reduced flux were observed at the lower temperature. The linoleic acid metabolism was significantly inhibited at low temperature, resulting in enhanced pyrimidine metabolism by Na+ accumulation. In addition, the biofilm at low temperature had a higher proportion of the metabolites of lipids and lipid-like molecules (11.25%), organic acids and derivatives (10.83%), nucleosides, nucleotides, and analogues (7.083%), and organoheterocyclic compounds (6.66%). These small molecules secrete more polysaccharides having C═O and O═C-O functional groups, which intensified the resistance of the biofilm. Furthermore, the upregulation pathway of pyrimidine metabolism also increased the risk of urea accumulation at low temperature. Limnohabitans, Deinococcus, Diaphorobacter, Flavobacterium, and Pseudomonas were identified as the principal microorganisms involved in this metabolic transformation.},
}
@article {pmid35622767,
year = {2022},
author = {Mahmoud, SF and Fayez, M and Swelum, AA and Alswat, AS and Alkafafy, M and Alzahrani, OM and Alsunaini, SJ and Almuslem, A and Al Amer, AS and Yusuf, S},
title = {Genetic Diversity, Biofilm Formation, and Antibiotic Resistance of Pseudomonas aeruginosa Isolated from Cow, Camel, and Mare with Clinical Endometritis.},
journal = {Veterinary sciences},
volume = {9},
number = {5},
pages = {},
doi = {10.3390/vetsci9050239},
pmid = {35622767},
issn = {2306-7381},
support = {Taif University Researchers Supporting Project number (TURSP-2020/138), Taif University, PO Box 11099, Taif 21944, Saudi Arabia.//Taif University/ ; },
abstract = {Pseudomonas aeruginosa is a ubiquitous opportunistic bacterium that causes diseases in animals and humans. This study aimed to investigate the genetic diversity, antimicrobial resistance, biofilm formation, and virulence and antibiotic resistance genes of P. aeruginosa isolated from the uterus of cow, camel, and mare with clinical endometritis and their drinking water. Among the 180 uterine swabs and 90 drinking water samples analysed, 54 (20%) P. aeruginosa isolates were recovered. Isolates were identified biochemically to the genus level by the automated Vitek 2 system and genetically by the amplification of the gyrB gene and the sequencing of the 16S rRNA gene. Multilocus sequence typing identified ten different sequence types for the P. aeruginosa isolates. The identification of ST2012 was significantly (p ≤ 0.05) higher than that of ST296, ST308, ST111, and ST241. The isolates exhibited significantly (p ≤ 0.05) increased resistance to piperacillin (77.8%), ciprofloxacin (59.3%), gentamicin (50%), and ceftazidime (38.9%). Eight (14.8%) isolates showed resistance to imipenem; however, none of the isolates showed resistance to colistin. Multidrug resistance (MDR) was observed in 24 isolates (44.4%) with a multiple antibiotic resistance index ranging from 0.44 to 0.77. MDR was identified in 30 (33.3%) isolates. Furthermore, 38.8% and 9.2% of the isolates exhibited a positive extended-spectrum-β-lactamase (ESBL) and metallo-β-lactamase (MBL) phenotype, respectively. The most prevalent β-lactamase encoding genes were blaTEM and blaCTX-M, however, the blaIPM gene was not detected in any of the isolates. Biofilm formation was observed in 49 (90.7%) isolates classified as: 11.1% weak biofilm producers; 38.9% moderate biofilm producers; 40.7% strong biofilm producers. A positive correlation was observed between the MAR index and biofilm formation. In conclusion, the results highlighted that farm animals with clinical endometritis could act as a reservoir for MDR and virulent P. aeruginosa. The emergence of ESBLs and MBLs producing P. aeruginosa in different farm animals is a public health concern. Therefore, surveillance programs to monitor and control MDR P. aeruginosa in animals are required.},
}
@article {pmid35622167,
year = {2022},
author = {Keymaram, M and Falahati, M and Farahyar, S and Lotfali, E and Abolghasemi, S and Mahmoudi, S and Sadeghi, F and Khalandi, H and Ghasemi, R and Shamsaei, S and Raiesi, O},
title = {Correction to: Anti-biofilm properties of eucalyptol in combination with antifungals against Candida albicans isolates in patients with hematological malignancy.},
journal = {Archives of microbiology},
volume = {204},
number = {6},
pages = {351},
doi = {10.1007/s00203-022-03019-0},
pmid = {35622167},
issn = {1432-072X},
}
@article {pmid35621538,
year = {2022},
author = {Xu, CP and Palazzolo, DL and Cuadra, GA},
title = {Mechanistic Effects of E-Liquids on Biofilm Formation and Growth of Oral Commensal Streptococcal Communities: Effect of Flavoring Agents.},
journal = {Dentistry journal},
volume = {10},
number = {5},
pages = {},
doi = {10.3390/dj10050085},
pmid = {35621538},
issn = {2304-6767},
abstract = {Background: Vaping has become a global health concern. As research continues, more studies are beginning to question the relative safety of E-liquid flavoring additives. The oral cavity is the first site of exposure to E-liquid aerosol, making it critical for investigation. Because of the importance of commensal bacterial biofilms for oral health, we sought to explore the effects of E-liquids ± flavors on the formation and growth of single- and multi-species biofilms and to investigate the mechanism of inhibition. Methods: Quantitative and confocal biofilm analysis, death curves, and colony-forming units (CFU) were evaluated with flavorless and flavored (tobacco, menthol, cinnamon, strawberry, blueberry) E-liquids using four strains of oral commensal bacteria (Streptococcus gordonii, Streptococcus intermedius, Streptococcus mitis, and Streptococcus oralis). Results: All flavoring agents show a dose-dependent inhibition in the growth of single-species and multi-species biofilms. Furthermore, CFUs, death curves, and light microscopy show that flavoring agents have a bactericidal mode of inhibition on the growth of these oral streptococci. Conclusions: These results show that flavored, rather than unflavored, E-liquids are more detrimental to biofilm formation and growth of oral commensal bacteria. Consequently, E-liquid flavorings agents could pose risks to the oral microenvironment, and by extension, to systemic health.},
}
@article {pmid35621500,
year = {2022},
author = {Pang, S and Rittmann, BE and Wu, C and Yang, L and Zhou, J and Xia, S},
title = {Synergistic Inorganic Carbon and Denitrification Genes Contributed to Nitrite Accumulation in a Hydrogen-Based Membrane Biofilm Reactor.},
journal = {Bioengineering (Basel, Switzerland)},
volume = {9},
number = {5},
pages = {},
doi = {10.3390/bioengineering9050222},
pmid = {35621500},
issn = {2306-5354},
support = {2021YFC3201300//National Key Project of Research and Development Plan of China/ ; NSFC 51678422//National Natural Science Foundation of China/ ; },
abstract = {Partial denitrification, the termination of NO3--N reduction at nitrite (NO2--N), has received growing interest for treating wastewaters with high ammonium concentrations, because it can be coupled to anammox for total-nitrogen removal. NO2- accumulation in the hydrogen (H2)-based membrane biofilm reactor (MBfR) has rarely been studied, and the mechanisms behind its accumulation have not been defined. This study aimed at achieving the partial denitrification with H2-based autotrophic reducing bacteria in a MBfR. Results showed that by increasing the NO3- loading, increasing the pH, and decreasing the inorganic-carbon concentration, a nitrite transformation rate higher than 68% was achieved. Community analysis indicated that Thauera and Azoarcus became the dominant genera when partial denitrification was occurring. Functional genes abundances proved that partial denitrification to accumulate NO2- was correlated to increases of gene for the form I RuBisCo enzyme (cbbL). This study confirmed the feasibility of autotrophic partial denitrification formed in the MBfR, and revealed the inorganic carbon mechanism in MBfR denitrification.},
}
@article {pmid35620882,
year = {2022},
author = {Xu, L and Qin, X and Mozaffari, MS and Yan, D and Sun, X and Cao, Y},
title = {Hybrid system with stable structure of hard/soft tissue substitutes induces re-osseointegration in a rat model of biofilm-mediated peri-implantitis.},
journal = {Journal of biomedical materials research. Part B, Applied biomaterials},
volume = {},
number = {},
pages = {},
doi = {10.1002/jbm.b.35102},
pmid = {35620882},
issn = {1552-4981},
support = {NZ17178//Natural Science Foundation of Ningxia Province/ ; 81700940//National Natural Science Foundation of China/ ; 81800981//National Natural Science Foundation of China/ ; 81860203//National Natural Science Foundation of China/ ; },
abstract = {Re-osseointegration of an infected/contaminated dental implant poses major clinical challenges. We tested the hypothesis that the application of an antibiotic-releasing construct, combined with hard/soft tissue replacement, increases the efficacy of reconstructive therapy. We initially fabricated semi-flexible hybrid constructs of β-TCP/PHBHHx, with tetracycline (TC) (TC amounts: 5%, 10%, and 15%). Thereafter, using in vitro assays, TC release profile, attachment to rat bone marrow-derived stem cells (rBMSCs) and their viability as well as anti-bacterial activity were determined. Thereafter, regenerative efficacies of the three hybrid constructs were assessed in a rat model of peri-implantitis induced by Aggregatibacter actinomycetemcomitans biofilm; control animals received β-TCP/Bio-Gide and TC injection. Eight weeks later, maxillae were obtained for radiological, histological, and histomorphometric analyses of peri-implant tissues. Sulcus bleeding index was chronologically recorded. Serum cytokines levels of IL-6 and IL-1β were also evaluated by enzyme-linked immunosorbent assay. Substantial amounts of tetracycline, from hybrid constructs, were released for 2 weeks. The medium containing the released tetracycline did not affect the adhesion or viability of rBMSCs; however, it inhibited the proliferation of A. actinomycetemcomitans. Osteogenesis and osseointegration were more marked for the 15% hybrid construct group than the other two groups. The height of attachment and infiltration of inflammatory cells within fibrous tissue was significantly reduced in the experimental groups than the control group. Our protocol resulted in re-osseointegration on a biofilm-contaminated implant. Thus, an antibiotic releasing inorganic/organic construct may offer a therapeutic option to suppress infection and promote guided tissue regeneration thereby serving as an integrated multi-layer substitute for both hard/soft tissues.},
}
@article {pmid35619831,
year = {2022},
author = {Knoll, MT and Fuderer, E and Gescher, J},
title = {Sprayable biofilm - Agarose hydrogels as 3D matrix for enhanced productivity in bioelectrochemical systems.},
journal = {Biofilm},
volume = {4},
number = {},
pages = {100077},
doi = {10.1016/j.bioflm.2022.100077},
pmid = {35619831},
issn = {2590-2075},
abstract = {Bio-based energy production utilizing renewable resources can be realized by exoelectrogenic organisms and their application in bioelectrochemical systems (BES). These organisms catalyze the direct conversion of chemical into electrical energy and are already widely used in bioelectronics and biosensing. However, the biofilm-electrode interaction is a factor that limits sufficient space-time-yields for industrial applications. In this study, a hydrogel matrix consisting of agarose fibers was utilized as a scaffold for S. oneidensis cells to improve anodic processes in BES. This synthetic, scalable biofilm reached a higher current density in BES in comparison to naturally formed biofilms. Complemented with carbon nanofibers and riboflavin, the application of this functionalized hydrogel containing S. oneidensis cells led to an overall 9.1-fold increase in current density to 1324 mA m-2 in comparison to 145 mA m-2 for the planktonic control. In addition, the synthetic biofilm can be applied by spraying onto surfaces using a novel spray applicator. The latter allows to apply the biofilm effortless on large surfaces which will facilitate scalability and thus industrial application.},
}
@article {pmid35619519,
year = {2019},
author = {Cao, J and Zhao, Y and Liu, Y and Tian, S and Zheng, C and Liu, C and Zhai, Y and An, Y and Busscher, HJ and Shi, L and Liu, Y},
title = {Phosphorylcholine-Based Polymer Encapsulated Chitosan Nanoparticles Enhance the Penetration of Antimicrobials in a Staphylococcal Biofilm.},
journal = {ACS macro letters},
volume = {8},
number = {6},
pages = {651-657},
doi = {10.1021/acsmacrolett.9b00142},
pmid = {35619519},
issn = {2161-1653},
abstract = {Biofilms that contribute to the persistent bacterial infections pose serious threats to human health, due in part to the extracellular polymeric substances (EPS) matrix of biofilm block the diffusion of intact antimicrobials. The poor penetration of antimicrobials into biofilm greatly reduces their bacterial killing efficacy. Here, we have demonstrated a nanocapsule PMPC-CS synthesized by encapsulating a chitosan nanoparticle with poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC). Such PMPC-based surface exhibited low EPS-adsorption, allowing enhanced penetration of PMPC-CS. Additionally, PMPC-CS showed effective targeting toward negatively charged bacterial cell surfaces and pH-responsive drug release mediated by the swelling of chitosan core under the acidic environment of biofilm. These unique features ensured targeted delivery of antimicrobials throughout the depth of a biofilm. Delivery of triclosan with PMPC-CS outperformed direct application of free triclosan in inhibiting the growth of bacteria in biofilm, suggesting the potential of PMPC-CS as an effective delivery system for the treatment of bacterial infections.},
}
@article {pmid35619411,
year = {2019},
author = {Park, HH and Sun, K and Seong, M and Kang, M and Park, S and Hong, S and Jung, H and Jang, J and Kim, J and Jeong, HE},
title = {Lipid-Hydrogel-Nanostructure Hybrids as Robust Biofilm-Resistant Polymeric Materials.},
journal = {ACS macro letters},
volume = {8},
number = {1},
pages = {64-69},
doi = {10.1021/acsmacrolett.8b00888},
pmid = {35619411},
issn = {2161-1653},
abstract = {Despite extensive efforts toward developing antibiofilm materials, efficient prevention of biofilm formation remains challenging. Approaches based on a single strategy using either bactericidal material, antifouling coatings, or nanopatterning have shown limited performance in the prevention of biofilm formation. This study presents a hybrid strategy based on a lipid-hydrogel-nanotopography hybrid for the development of a highly efficient and durable biofilm-resistant material. The hybrid material consists of nanostructured antifouling, biocompatible polyethylene glycol-based polymer grafted with an antifouling zwitterionic polymer of 2-methacryloyloxyethyl phosphorylcholine. Based on the unique composite nanostructures, the lipid-hydrogel-nanostructure hybrid exhibits superior dual functionalities of antifouling and bactericidal activities against Gram-negative and Gram-positive bacteria, compared with those of surfaces with simple nanostructures or antifouling coatings. Additionally, it preserves the robust antibiofilm activity even when the material is damaged under external mechanical stimuli thanks to the polymeric composite nanostructure.},
}
@article {pmid35619261,
year = {2022},
author = {Yadav, J and Das, S and Karthikeyan, D and Chug, R and Jyoti, A and Srivastava, VK and Jain, A and Kumar, S and Sharma, V and Kaushik, S},
title = {Identification of Protein drug targets of Biofilm formation and Quorum sensing in multidrug resistant Enterococcus faecalis.},
journal = {Current protein &amp; peptide science},
volume = {},
number = {},
pages = {},
doi = {10.2174/1389203723666220526155644},
pmid = {35619261},
issn = {1875-5550},
abstract = {Enterococcus faecalis (E. faecalis) is an opportunistic multidrug-resistant (MDR) pathogen found in the guts of humans and farmed animals. Due to the occurrence of (MDR) strain there is an urgent need to look for an alternative treatment approach. E. faecalis is a Gram-positive bacterium, which is presently amongst the most prevalent multidrug resistant hospital pathogens. Its ability to develop quorum sensing (QS) mediated biofilm formation further exacerbates the pathogenicity and triggers life- threatening infections. Therefore, developing a suitable remedy for curing E. faecalis mediated enterococcal infections is an arduous task. Several putative virulence factors and proteins are involved in the development of biofilms in E. faecalis. Such proteins often play important roles in virulence, disease, and colonization by pathogens. The elucidation of the structure-function relationship of such protein drug targets and the interacting compounds could provide an attractive paradigm towards developing structure-based drugs against E. faecalis. This review provides a comprehensive overview of the current status, enigmas that warrant further studies, and the prospects toward alleviating the antibiotic resistance in E. faecalis. Specifically, the role of biofilm and quorum sensing (QS) in the emergence of MDR strains had been elaborated along with the importance of the protein drug targets involved in both the processes.},
}
@article {pmid35616791,
year = {2022},
author = {Mamonova, IA and Babushkina, IV and Ulyanov, VY and Shpinyak, SP},
title = {Kinetics of the Growth of Enterococcus spp. Biofilm Formed by Strains Isolated from Patients with Infectious Complications after Large joint Replacements.},
journal = {Bulletin of experimental biology and medicine},
volume = {},
number = {},
pages = {},
pmid = {35616791},
issn = {1573-8221},
abstract = {We studied the kinetics of growth of biofilms and plankton forms of Enterococcus spp. strains isolated in implant-associated infection of large joints. The capacity for biofilm formation by enterococci was demonstrated. The following stages of biofilm formation were revealed: biofilm formation and maturation, its degradation, and secondary dissemination. These findings extend our understanding of the wound process caused by enterococci.},
}
@article {pmid35616277,
year = {2022},
author = {Ning, Y and Wang, X and Chen, P and Liu, S and Hu, J and Xiao, R and Li, L and Lu, F},
title = {Targeted inhibition of methicillin-resistant Staphylococcus aureus biofilm formation by a graphene oxide-loaded aptamer/berberine bifunctional complex.},
journal = {Drug delivery},
volume = {29},
number = {1},
pages = {1675-1683},
doi = {10.1080/10717544.2022.2079768},
pmid = {35616277},
issn = {1521-0464},
abstract = {Biofilm formation is known to promote drug resistance in methicillin-resistant Staphylococcus aureus (MRSA), which is closely related to persistent infections in hospital settings. In this study, a DNA aptamer specific to penicillin-binding protein 2a (PBP2a) with a dissociation constant (Kd) of 82.97 ± 8.86 nM was obtained after 14 cycles of systematic evolution of ligands by exponential enrichment (SELEX). Next, a bifunctional complex containing the aptamer intercalated by berberine into the double-strand region was prepared and adsorbed onto the surface of graphene oxide (GO) by π-stacking interactions. The GO-loaded aptamer/berberine bifunctional complex showed significantly higher inhibition of MRSA biofilm formation than the control. Furthermore, this study shows that the complex possesses anti-biofilm activity, which can be attributed to the ability of the aptamer to reduce cell-surface attachment by blocking the function of PBP2a and berberine to attenuate the level of the accessory gene regulator (agr) system, which plays an important role in mediating MRSA biofilm formation. Therefore, the simultaneous delivery of berberine and PBP2a-targted aptamer using GO may have potential for the treatment of chronic infections caused by MRSA biofilms. It also provides a new avenue for multitarget treatment of bacterial biofilms.},
}
@article {pmid35615510,
year = {2022},
author = {Budroni, M and Torija, MJ and Moreno-García, J and Zara, G},
title = {Editorial: Biofilm and Food: Well- and Lesser-Known Interactions.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {923021},
doi = {10.3389/fmicb.2022.923021},
pmid = {35615510},
issn = {1664-302X},
}
@article {pmid35614284,
year = {2022},
author = {Dong, M and Yang, X and Liu, L and Zhou, Z and Deng, L and Zhong, Z and Liu, H and Ma, X and Fu, H and Cao, S and Shen, L and Peng, G},
title = {Role of Hfq in glucose utilization, biofilm formation and quorum sensing system in Bacillus subtilis.},
journal = {Biotechnology letters},
volume = {},
number = {},
pages = {},
pmid = {35614284},
issn = {1573-6776},
support = {CPF2015-09//Chengdu Giant Panda Breeding Research Foundation/ ; CPF2017-12//Chengdu Giant Panda Breeding Research Foundation/ ; },
abstract = {Hfq is an RNA-binding protein, its main function is to participate in post-transcriptional regulation of bacteria and regulate small regulatory RNA (sRNA) and messenger RNA (mRNA) stability, but the Hfq function of Bacillus subtilis (B. subtilis) has not been fully explained. In this study, we used the strains of B. subtilis168 (BS168), BS168Δhfq and BS168Δhfq-C to explore the effects of Hfq on the glucose utilization, biofilm formation and quorum sensing (QS) system of B. subtilis. The results showed that the knockout of hfq resulted in growth defects when bacteria were cultured in the Luria-Bertani (LB) medium, but we did not observe the same effects in Nitrogen medium (NM) and Inorganic Salt-free medium (ISM). We further found that the growth of strains under different glucose concentrations was also different, which was related to the expression of CcpA. Interestingly, the hfq mutant showed increased resistance to a high-glucose environment. Furthermore, the biofilm and extracellular poly saccharides (EPS) formation of BS168Δhfq decreased significantly. At the same time, changes were observed in the morphology of the biofilm, such as larger intercellular space of the biofilm and thinner edge. The qRT-PCR results confirmed that the hfq knockout caused significant up-regulation or down-regulation of gene expression in QS system, and down-regulated genes were involved in the positive regulation of biofilm formation. Taken together, we demonstrated that Hfq plays a vital role in glucose utilization, biofilm formation and QS of B. subtilis, which provides a new perspective for subsequent related research.},
}
@article {pmid35614186,
year = {2022},
author = {Ciecholewska-Juśko, D and Żywicka, A and Junka, A and Woroszyło, M and Wardach, M and Chodaczek, G and Szymczyk-Ziółkowska, P and Migdał, P and Fijałkowski, K},
title = {The effects of rotating magnetic field and antiseptic on in vitro pathogenic biofilm and its milieu.},
journal = {Scientific reports},
volume = {12},
number = {1},
pages = {8836},
pmid = {35614186},
issn = {2045-2322},
support = {2017/27/B/NZ6/02103//Narodowe Centrum Nauki/ ; },
abstract = {The application of various magnetic fields for boosting the efficacy of different antimicrobial molecules or in the character of a self-reliant antimicrobial agent is considered a promising approach to eradicating bacterial biofilm-related infections. The purpose of this study was to analyze the phenomenon of increased activity of octenidine dihydrochloride-based antiseptic (OCT) against Staphylococcus aureus and Pseudomonas aeruginosa biofilms in the presence of the rotating magnetic field (RMF) of two frequencies, 5 and 50 Hz, in the in vitro model consisting of stacked agar discs, placed in increasing distance from the source of the antiseptic solution. The biofilm-forming cells' viability and morphology as well as biofilm matrix structure and composition were analyzed. Also, octenidine dihydrochloride permeability through biofilm and porous agar obstacles was determined for the RMF-exposed versus unexposed settings. The exposure to RMF or OCT apart did not lead to biofilm destruction, contrary to the setting in which these two agents were used together. The performed analyses revealed the effect of RMF not only on biofilms (weakening of cell wall/membranes, disturbed morphology of cells, altered biofilm matrix porosity, and composition) but also on its milieu (altered penetrability of octenidine dihydrochloride through biofilm/agar obstacles). Our results suggest that the combination of RMF and OCT can be particularly promising in eradicating biofilms located in such areas as wound pockets, where physical obstacles limit antiseptic activity.},
}
@article {pmid35613523,
year = {2022},
author = {Guliy, OI and Evstigneeva, SS and Bunin, VD},
title = {Microfluidic bioanalytical system for biofilm formation indication.},
journal = {Talanta},
volume = {247},
number = {},
pages = {123541},
doi = {10.1016/j.talanta.2022.123541},
pmid = {35613523},
issn = {1873-3573},
abstract = {The formation of biofilms is a key factor that researchers must consider when they work with bacterial cultures. We describe a new microfluidic bioanalytical sensory system for indicating biofilm formation. The method is demonstrated with Pseudomonas bacteria as an example and is based on the real-time recording of cell-polarizability changes caused by an alternating electric field. Control experiments using phase-contrast microscopy and traditional microbiological plating were done that proved biofilms had formed. The physical picture was described of the sensor-signal changes during cell transition from planktonic to biofilm growth. This transition was indicated by the appearance of a peak-shaped signal at 500 kHz and by an increase in the recorded relaxation time. Phenomena of increase in the signal relaxation time from 2.4 s for planktonic to 25.4 s for biofilm cells. The proposed microfluidic sensor system for indicating biofilm formation holds much promise, because it ensures an analysis time of about 20-30 min. An added bonus is that for this system there is no need to grow bacterial biofilms in a sensor and the flow cell is reusable.},
}
@article {pmid35612797,
year = {2022},
author = {Prado, MM and Figueiredo, N and Pimenta, AL and Miranda, TS and Feres, M and Figueiredo, LC and de Almeida, J and Bueno-Silva, B},
title = {Recent Updates on Microbial Biofilms in Periodontitis: An Analysis of In Vitro Biofilm Models.},
journal = {Advances in experimental medicine and biology},
volume = {1373},
number = {},
pages = {159-174},
pmid = {35612797},
issn = {0065-2598},
abstract = {The development of oral biofilm models has been extremely important to study the specific role of most microbial species at the early stages of periodontitis. The current knowledge on monospecies or multispecies biofilms originates mainly from the observation of in vitro dynamic or static biofilm model systems, which were engineered to mimic clinical oral conditions. In the last few decades, mounting evidence has confirmed that biofilms are the major form of bacterial lifestyle, and more importantly, that microorganisms dwelling in sessile mixed-species aggregates display completely different phenotypes and physiological characteristics than when living in planktonic pure cultures. Interspecies interactions within these communities, mediated by chemical communication systems, have been shown to affect biofilm physiology and increase antimicrobial resistance by up to 1000 fold. These aspects reinforce the importance of developing multispecies biofilm models to better understand and control biofilms. Literature reports demonstrate that while monospecies models are still most commonly used in caries research, authors have used different multispecies models to study periodontal diseases. Periodontitis is a polymicrobial biofilm-dependent disease mainly associated with Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola. Interestingly, these species hardly adhere to substrates commonly used for biofilm formation, which makes multispecies models essential for an accurate analysis of periodontitis-related biofilms. The multispecies models currently available are generally composed of 6-10 species, but a more recent 34-species model was developed to better examine the dynamics within oral biofilms. The complexity of such polymicrobial biofilm models mimics more consistently the oral microbiome and different aspects of the oral environment. Collectively, the evidence on multispecies biofilm models described herein may support future studies on the use of antimicrobials for biofilm control as well as provide research opportunities to expand the current knowledge on interspecies interactions. The present manuscript reviews the most recent updates on in vitro biofilm model systems for periodontitis.},
}
@article {pmid35612628,
year = {2022},
author = {Vega, M and Ontiveros-Valencia, A and Vargas, IT and Nerenberg, R},
title = {Chlorate addition enhances perchlorate reduction in denitrifying membrane-biofilm reactors.},
journal = {Applied microbiology and biotechnology},
volume = {},
number = {},
pages = {},
pmid = {35612628},
issn = {1432-0614},
support = {21161573//Agencia Nacional de Investigación y Desarrollo de Chile/ ; 1201134//Fondo Nacional de Desarrollo Científico y Tecnológico/ ; 15110020//Centro de Desarrollo Urbano Sustentable ANID/FONDAP/ ; },
abstract = {Perchlorate is a widespread drinking water contaminant with regulatory standards ranging from 2 to 18 μg/L. The hydrogen-based membrane-biofilm reactor (MBfR) can effectively reduce perchlorate, but it is challenging to achieve low-µg/L levels. We explored chlorate addition to increase the abundance of perchlorate-reducing bacteria (PRB) and improve removals. MBfR reactors were operated with and without chlorate addition. Results show that chlorate doubled the abundance of putative PRB (e.g., Rhodocyclales) and improved perchlorate reduction to 23 ± 17 µg/L, compared to 53 ± 37 µg/L in the control. Sulfate reduction was substantially inhibited during chlorate addition, but quickly recovered once suspended. Our results suggest that chlorate addition can enhance perchlorate reduction by providing a selective pressure for PRB. It also decreases net sulfate reduction. KEY POINTS: • Chlorate increased the abundance of perchlorate-reducing bacteria • Chlorate addition improved perchlorate removal • Chlorate appeared to suppress sulfate reduction.},
}
@article {pmid35611764,
year = {2022},
author = {Wu, X and Wang, B and Ma, Q and Zhang, Y and Xu, J and Zhang, Z and Chen, G},
title = {Mechanism of erythropoietin-induced M2 microglia polarization via Akt / Mtor / P70S6k signaling pathway in the treatment of brain injury in premature mice and its effect on biofilm.},
journal = {Bioengineered},
volume = {13},
number = {5},
pages = {13021-13032},
doi = {10.1080/21655979.2022.2073000},
pmid = {35611764},
issn = {2165-5987},
abstract = {We investigated the mechanism of erythropoietin (EPO) in brain injury in premature mice based on Akt/mTOR/p70S6K signaling pathway. The brain injury model group of premature mice was obtained by intraperitoneal injection of lipopolysaccharide during pregnancy. Normal mice were taken as the control group. The model mice were divided into low-dose EPO (1,000 IU/kg, L-EPO), medium-dose EPO (2,500 IU/kg, M-EPO), and high-dose EPO groups (5,000 IU/kg, H-EPO) by intraperitoneal injection. The levels of malondialdehyde (MDA) and total superoxide dismutase (T-SOD) were detected. TUNEL staining and Western blotting were used to detect the differences in neuronal apoptosis index (AI), microglial polarization marker protein, and Akt/mTOR/p70S6K-related protein expression levels in each group. Compared with the control group, the protein levels of AI, MDA, Bax, and iNOS in the model, L-EPO, and M-EPO groups were significantly increased, while the T-SOD level and Bcl-2, ARG1, p-Akt, p-mTOR, and p-70S6K protein levels were significantly decreased (P < 0.05). Compared with the model group, AI, MAD levels and Bax, iNOS protein expression levels in L-EPO, M-EPO, and H-EPO groups were significantly decreased, while T-SOD level and Bcl-2, ARG1, p-Akt, p-mTOR, and p-70S6K protein levels were significantly increased. The changes were dose-dependent. In summary, EPO can activate microglia transformation from M1 to M2 through Akt/mTOR/p70S6K signaling pathway.},
}
@article {pmid35610631,
year = {2022},
author = {Xia, Y and Jayathilake, PG and Li, B and Zuliani, P and Deehan, D and Longyear, J and Stoodley, P and Chen, J},
title = {Coupled CFD-DEM modelling to predict how EPS affects bacterial biofilm deformation, recovery and detachment under flow conditions.},
journal = {Biotechnology and bioengineering},
volume = {},
number = {},
pages = {},
doi = {10.1002/bit.28146},
pmid = {35610631},
issn = {1097-0290},
abstract = {The deformation and detachment of bacterial biofilm are related to the structural and mechanical properties of the biofilm itself. Extracellular polymeric substances (EPS) play an important role on keeping the mechanical stability of biofilms. The understanding of biofilm mechanics and detachment can help to reveal biofilm survival mechanisms under fluid shear and provide insight about what flows might be needed to remove biofilm in a cleaning cycle or for a ship to remove biofilms. However, how the EPS may affect biofilm mechanics and its deformation in flow conditions remains elusive. To address this, a coupled computational fluid dynamic - discrete element method (CFD-DEM) model was developed. The mechanisms of biofilm detachment, such as erosion and sloughing have been revealed by imposing hydrodynamic fluid flow at different velocities and loading rates. The model, which also allows adjustment of the proportion of different functional groups of microorganisms in the biofilm, enables the study of the contribution of EPS towards biofilm resistance to fluid shear stress. Furthermore, the stress-strain curves during biofilm deformation have been captured by loading and unloading fluid shear stress to study the viscoelastic properties of the biofilm. Our predicted emergent viscoelastic properties of biofilms were consistent with relevant experimental measurements. This article is protected by copyright. All rights reserved.},
}
@article {pmid35609749,
year = {2022},
author = {Leggieri, PA and Valentine, MT and O'Malley, MA},
title = {Biofilm disruption enhances growth rate and carbohydrate-active enzyme production in anaerobic fungi.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {127361},
doi = {10.1016/j.biortech.2022.127361},
pmid = {35609749},
issn = {1873-2976},
abstract = {Anaerobic gut fungi (AGF) are lignocellulose degraders that naturally form biofilms in the rumen of large herbivores and in standard culture techniques. While biofilm formation enhances biomass degradation and carbohydrate active enzyme (CAZyme) production in some bacteria and aerobic fungi, gene expression and metabolism in AGF biofilms have not been compared to non-biofilm cultures. Here, using the tunable morphology of the non-rhizoidal AGF, Caecomyces churrovis, the impacts of biofilm formation on AGF gene expression, metabolic flux, growth rate, and xylan degradation rate are quantified to inform future industrial scale-up efforts. Contrary to previous findings, C. churrovis upregulated catabolic CAZymes in stirred culture relative to biofilm culture. Using a de novo transcriptome, 197 new transcripts with predicted CAZyme function were identified. Stirred cultures grew and degraded xylan significantly faster than biofilm-forming cultures with negligible differences in primary metabolic flux, offering a way to accelerate AGF biomass valorization without altering the fermentation product profile. The rhizoidal AGF, Neocallimastix lanati, also grew faster with stirring on a solid plant substrate, suggesting that the advantages of stirred C. churrovis cultures may apply broadly to other AGF.},
}
@article {pmid35607251,
year = {2022},
author = {Han, X and Lou, Q and Feng, F and Xu, G and Hong, S and Yao, L and Qin, S and Wu, D and Ouyang, X and Zhang, Z and Wang, X},
title = {Spatiotemporal Release of ROS and NO for Overcoming Biofilm Heterogeneity.},
journal = {Angewandte Chemie (International ed. in English)},
volume = {},
number = {},
pages = {},
doi = {10.1002/anie.202202559},
pmid = {35607251},
issn = {1521-3773},
abstract = {The heterogeneity in biofilm is a major challenge in biofilm therapies due to different susceptibility of bacteria and extracellular polymeric substances (EPS) to antibacterial agents. Here, we described a therapeutic strategy that overcame biofilm heterogeneity, where antibacterial agent (NO) and EPS dispersant (reactive oxygen species (ROS)-inducing Fe 3+) were separately loaded in the yolk and shell compartment of a yolk-shell nanoplatform. Compared with traditional combinational chemotherapies which suffer from inconsistent pharmacokinetics profiles, this strategy drew on the pharmacokinetic complementarity of ROS and NO, where ROS with a short diffusion distance and a high redox potential corrupted the EPS, facilitating NO, which has a long diffusion distance and a broad antimicrobial spectrum, to penetrate the biofilm and eliminate the resident bacteria. Additionally, the construction of three-dimensional spherical biofilm model is novel and clinically relevant.},
}
@article {pmid35606635,
year = {2022},
author = {Swain, G and Maurya, KL and Kumar, M and Sonwani, RK and Singh, RS and Jaiswal, RP and Nath Rai, B},
title = {The Biodegradation of 4-Chlorophenol in a Moving Bed Biofilm Reactor Using Response Surface Methodology: Effect of Biogenic Substrate and Kinetic Evaluation.},
journal = {Applied biochemistry and biotechnology},
volume = {},
number = {},
pages = {},
pmid = {35606635},
issn = {1559-0291},
abstract = {4-Chlorophenol (4-CP) is a persistent organic pollutant commonly found in petrochemical effluents. It causes toxic, carcinogenic and mutagenic effects on human beings and aquatic lives. Therefore, an environmentally benign and cost-effective approach is needed against such pollutants. In this direction, the chlorophenol degrading bacterial consortium consisting of Bacillus flexus GS1 IIT (BHU) and Bacillus cereus GS2 IIT (BHU) was isolated from a refinery site. A composite biocarrier namely polypropylene-polyurethane foam (PP-PUF) was developed for bacterial cells immobilization purpose. A lab-scale moving bed biofilm reactor (MBBR) packed with Bacillus sp. immobilized PP-PUF biocarrier was employed to analyse the effect of peptone on biodegradation of 4-CP. The statistical tool, i.e. response surface methodology (RSM), was used to optimize the process variables (4-CP concentration, peptone concentration and hydraulic retention time). The higher values of peptone concentration and hydraulic retention time were found to be favourable for maximum removal of 4-CP. At the optimized process conditions, the maximum removals of 4-CP and chemical oxygen demand (COD) were obtained to be 91.07 and 75.29%, respectively. In addition, three kinetic models, i.e. second-order, Monod and modified Stover-Kincannon models, were employed to investigate the behaviour of MBBR during 4-CP biodegradation. The high regression coefficients obtained by the second-order and modified Stover-Kincannon models showed better accuracy for estimating substrate degradation kinetics. The phytotoxicity study supported that the Vigna radiata seeds germinated in treated wastewater showed higher growth (i.e. radicle and plumule) than the untreated wastewater.},
}
@article {pmid35606284,
year = {2022},
author = {Alabdullatif, M and Alzahrani, A},
title = {Expression of biofilm-associated genes in Staphylococcus aureus during storage of platelet concentrates.},
journal = {Transfusion and apheresis science : official journal of the World Apheresis Association : official journal of the European Society for Haemapheresis},
volume = {},
number = {},
pages = {103456},
doi = {10.1016/j.transci.2022.103456},
pmid = {35606284},
issn = {1473-0502},
abstract = {BACKGROUND AND OBJECTIVES: In transfusion medicine, the safety of platelet concentrates (PCs) is a major concern on account of contamination, mostly with Staphylococcus species. One of the most common contaminants is Staphylococcus aureus, which forms bacterial biofilms in PCs, posing a safety risk for transfusion patients. In this study, we investigate the contributions to biofilm formation of eno, ebps, and fib genes encoding surface proteins and of genes from the ica operon (icaA and icaD) encoding polysaccharide intercellular adhesin (PIA), along with their expression in bacteria grown in glucose-supplemented trypticase soy broth (TSBg) and PCs.<br><br>MATERIALS AND METHODS: Two strains of S. aureus (2039 and 2110) captured during routine PC screening were tested for biofilm formation in TSBg and under PC storage conditions, with mRNA collected at five time points and analyzed to determine expression of eno, ebps, fib, icaA, and icaD and their contributions to biofilm formation in both media.<br><br>RESULTS: In TSBg, S. aureus strain 2039 formed weak biofilms while 2110 formed strong. biofilms; however, in PCs, both strains formed strong biofilms. During biofilm formation, expression levels of icaA and icaD in both strains were generally significantly higher in TSBg than PCs. In contrast, expression of eno, ebps, and fib genes tended to be significantly higher under PC storage conditions.<br><br>CONCLUSION: This study demonstrated that expression of genes involved in biofilm formation can be affected by growth media. Further investigation is needed to understand biofilm formation in the PC milieu and enhance transfusion safety.},
}
@article {pmid35605925,
year = {2022},
author = {Joseph, B and Gopalakrishnan, S and Alamoudi, RA and Alamoudi, RA and Pachathundikandi, SK and Alotaibi, RN and Anil, S},
title = {Detection of invisible dental biofilm using light-induced autofluorescence in adult patients - a systematic review.},
journal = {Photodiagnosis and photodynamic therapy},
volume = {},
number = {},
pages = {102916},
doi = {10.1016/j.pdpdt.2022.102916},
pmid = {35605925},
issn = {1873-1597},
abstract = {BACKGROUND: Autofluorescence (AF) spectroscopy is a potent yet non-invasive technique with diagnostic and therapeutic applications. It identifies and characterizes changes occurring in the human body based on the changes in the fluorescence signatures.<br><br>AIM: The primary purpose of this systematic review is to address the question "Is it feasible to detect dental plaque using light-induced auto-fluorescence in adult patients with invisible grade 1 plaque?"<br><br>MATERIALS AND METHODS: The literature search was conducted independently Medline, EMBASE, Cochrane Library, Web of Science, Google Scholar, and Scopus databases for relevant studies from January 2000 and June 2021, using the following terms in various combinations: detection, dental biofilm, plaque, light, auto-fluorescence, caries, gingivitis, sensitivity and specificity. Studies describing various fluorescence techniques for the detection of plaque, including sensitivity and specificity, were included.<br><br>RESULTS: The majority of the studies indicated that AF spectroscopy allows fluorescence-based detection of various diseases, including early-stage dental plaque. While results of conventional plaque detection techniques are inconsistent, the data from the AF technique is reliable and reproducible, which can be used for patient documentation. However, a wide range of non-uniformity existed in these studies. AF spectroscopy, as a non-invasive technique, represents a viable and patient-friendly clinical tool for the early detection of dental biofilm plaque, and its meticulous removal has been directly responsible for the prevention of this disease.<br><br>CONCLUSION: Despite the heterogeneity and limitations of studies included in this review, the future for light-induced autofluorescence spectroscopy technologies in diagnostic dentistry certainly presents an accurate and potentially applicable option.},
}
@article {pmid35605773,
year = {2022},
author = {Liu, W and Zhou, H and Zhao, W and Wang, C and Wang, Q and Wang, J and Wu, P and Shen, Y and Ji, X and Yang, D},
title = {Rapid initiation of a single-stage partial nitritation-anammox process treating low-strength ammonia wastewater: Novel insights into biofilm development on porous polyurethane hydrogel carrier.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {127344},
doi = {10.1016/j.biortech.2022.127344},
pmid = {35605773},
issn = {1873-2976},
abstract = {Media-supported biofilm is a powerful strategy for growth and enrichment of slow-growing microorganisms. In this study, a single-stage nitritation-anammox process treating low-strength wastewater was successfully started to investigate the biofilm development on porous polyurethane hydrogel carrier. Suspended biomass migration into the carrier and being entrapment by its internal interconnected micropores dominated the fast initial colonization stage. Both surface-attached growth and embedded growth of microbes occurred during the following accumulation stage. Fluorescence in situ hybridization analysis of mature biofilm indicated that ammonium-oxidizing bacteria located at the outer layers featured a surface-attached growth, while anammox microcolonies housed in the inner layers proliferated as an embedded-like growth. In this way, the growth rate of anammox bacteria (predominated by Candidatus Kuenenia) could be 0.079 d-1. The anammox potential of the biofilm reactor reached 1.65±0.3 kg/m3/d within two months. This study provides novel insights into nitritation-anammox biofilm formation on the porous polyurethane hydrogel carrier.},
}
@article {pmid35605730,
year = {2022},
author = {Bourguignon, N and Alessandrello, M and Booth, R and Lobo, CB and Tomás, SJ and Cumbal, L and Perez, M and Bhansali, S and Ferrero, M and Lerner, B},
title = {Bioremediation on a chip: A portable microfluidic device for efficient screening of bacterial biofilm with polycyclic aromatic hydrocarbon removal capacity.},
journal = {Chemosphere},
volume = {},
number = {},
pages = {135001},
doi = {10.1016/j.chemosphere.2022.135001},
pmid = {35605730},
issn = {1879-1298},
abstract = {Polycyclic aromatic hydrocarbons (PAHs) are pollutants of critical environmental and public health concern and their elimination from contaminated sites is significant for the environment. Biodegradation studies have demonstrated the ability of bacteria in biofilm conformation to enhance the biodegradation of pollutants. In this study, we used our newly developed microfluidic platform to explore biofilm development, properties, and applications of fluid flow, as a new technique for screening PAHs-degrading biofilms. The optimization and evaluation of the flow condition in the microchannels were performed through computational fluid dynamics (CFD). The formation of biofilms by PAHs-degrading bacteria Pseudomonas sp. P26 and Gordonia sp. H19, as pure cultures and co-culture, was obtained in the developed microchips. The removal efficiencies of acenaphthene, fluoranthene and pyrene were determined by HPLC. All the biofilms formed in the microchips removed all tested PAHs, with the higher removal percentages observed with the Pseudomonas sp. P26 biofilm (57.4% of acenaphthene, 40.9% of fluoranthene, and 28.9% of pyrene). Pseudomonas sp. P26 biofilm removed these compounds more efficiently than planktonic cultures. This work proved that the conformation of biofilms enhances the removal rate. It also provided a new tool to rapid and low-cost screen for effective pollutant-degrading biofilms.},
}
@article {pmid35605455,
year = {2022},
author = {Pang, X and Zhang, H and Seck, HL and Zhou, W},
title = {Inactivation effect of low-energy X-ray irradiation against planktonic and biofilm Pseudomonas fluorescens and its antibacterial mechanism.},
journal = {International journal of food microbiology},
volume = {374},
number = {},
pages = {109716},
doi = {10.1016/j.ijfoodmicro.2022.109716},
pmid = {35605455},
issn = {1879-3460},
abstract = {Pseudomonas fluorescens is a well-known biofilm former on food contact surfaces and can cause severe cross-contamination in food processing premises. This study aimed to determine the inactivation effect of low-energy X-ray on P. fluorescens planktonic cells in phosphate-buffered saline solution (PBS) and P. fluorescens biofilm cells on food-contact-surface (stainless steel). The results demonstrated that low-energy X-ray irradiation at 125 Gy inactivated 4.60 log CFU/mL and 4.21 log CFU/cm2 for P. fluorescens planktonic and biofilm cells, respectively. Based on Weibull model, low-energy X-ray achieved tR1 values of 14.8 Gy and 11.6 Gy for P. fluorescens planktonic and biofilm cells, respectively. Apart from cell inactivation, the irradiation also led to the destruction of extracellular polymeric substances (EPS) structure. Low-energy X-ray irradiation markedly damaged bacterial glucose uptake system and resulted in part loss of bacterial membrane potential and integrity. These results suggested the potential of the low-energy X-ray for inactivating P. fluorescens biofilm cells and removing EPS in food industry.},
}
@article {pmid35605361,
year = {2022},
author = {Wang, Y and Pan, L and Li, L and Cao, R and Zheng, Q and Xu, Z and Wu, CJ and Zhu, H},
title = {Glycosylation increases the anti-QS as well as anti-biofilm and anti-adhesion ability of the cyclo (L-Trp-L-Ser) against Pseudomonas aeruginosa.},
journal = {European journal of medicinal chemistry},
volume = {238},
number = {},
pages = {114457},
doi = {10.1016/j.ejmech.2022.114457},
pmid = {35605361},
issn = {1768-3254},
abstract = {Pseudomonas aeruginosa infections pose a huge threat to cystic fibrosis patients, as well as those suffering from immunodeficiency. Antimicrobial resistance, especially multi-drug resistance, due to its ability to aggregate the compact biofilm, makes it more inefficient to treat this pathogen with traditional antibiotics. Biofilm and quorum sensing (QS) have become the alternative targets for treating P. aeruginosa infections. Previously, a cyclic dipeptide cyclo(L-Trp-L-Ser) has been identified as a QS inhibitor of P. aeruginosa. On the other hand, some monosaccharides have been proved lectin-targeting behavior and to mediate biofilm formation and adhesion of P. aeruginosa. We constructed novel cyclic dipeptide-carbohydrate conjugates as a low molecular weight dual-functional QS inhibitor, which can not only enhance its anti-QS activity but also enable good anti-biofilm and anti-adhesion ability. The IC50 of galactosylated c(WS) on biofilm formation and glass adhesion was 1/6 and 1/4 of that of the unmodified cyclic dipeptide, respectively. And the ability to eliminate the preformed biofilm was increased 10-fold. Furthermore, the carbohydrate conjugates can increase the germicidal efficiency of clinical antibiotic azithromycin when used synergistically. Our results provide a novel scaffold for developing anti-virulence adjuvants when taken with clinical antibiotics.},
}
@article {pmid35604533,
year = {2022},
author = {Wang, C and Li, C and Li, X and Cai, L and Han, Z and Du, R},
title = {Burn Wounds: Proliferating Site for Biofilm Infection.},
journal = {Applied biochemistry and biotechnology},
volume = {},
number = {},
pages = {},
pmid = {35604533},
issn = {1559-0291},
abstract = {Burn wounds can create significant damage to human skin, compromising one of the key barriers to infection. The leading cause of death among burn wound patients is infection. Even in the patients that survive, infections can be notoriously difficult to treat and can cause lasting damage, with delayed healing and prolonged hospital stays. Biofilm formation in the burn wound site is a major contributing factor to the failure of burn treatment regimens and mortality as a result of burn wound infection. Bacteria forming a biofilm or a bacterial community encased in a polysaccharide matrix are more resistant to disinfection, the rigors of the host immune system, and, critically, more tolerant to antibiotics. Burn wound-associated biofilms are also thought to act as a launchpad for bacteria to establish deeper, systemic infection, and ultimately bacteremia and sepsis. In this review, we discuss some of the leading burn wound pathogens and outline how they regulate biofilm formation in the burn wound microenvironment. We also discuss the new and emerging models that are available to study burn wound biofilm formation in vivo.},
}
@article {pmid35603698,
year = {2022},
author = {Khosravi, Y and Palmer, S and Daep, CA and Sambanthamoorthy, K and Kumar, P and Dusane, D and Stoodley, P},
title = {A commercial SnF2 toothpaste formulation reduces simulated human plaque biofilm in a dynamic typodont model.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/jam.15634},
pmid = {35603698},
issn = {1365-2672},
abstract = {AIMS: We present a dynamic typodont biofilm model (DTBM) incorporating 1) human dentition anatomy, 2) fluid flow over intermittently fluid bathed tooth surfaces and 3) an oxic headspace to allow aerobic and anaerobic niches to develop naturally, as a screening tool to assess the effect of stannous fluoride (SnF2) toothpaste against a simulated human plaque biofilm (SPB).<br><br>METHODS AND RESULTS: First, hydroxyapatite (HA) coupons were inoculated with human saliva/plaque and cultured at 37o C under air. Selected species representative of common commensal and anaerobic pathogens were quantified for relative abundance changes over 4d by PCR densitometry to confirm the culture conditions allowed the proliferation of these species. A continuous culture DTBM reactor on a rocker table was inoculated with saliva/plaque and incubated at 37°C for 24h. Tooth shear stress was estimated by particle tracking. A SnF2 toothpaste solution, or a sham rise was administered twice daily for 3d to mimic routine oral hygiene. SPB biomass was assessed by total bacterial DNA and methylene blue (MB) staining. Early colonizer aerobes and late colonizer anaerobes species were detected in the HA and DTBM, and the trends in changing abundance were consistent with those seen clinically.<br><br>CONCLUSIONS: Treatment with the SnF2 solution showed significant reductions of 53.05% and 54.4% in the SPB by MB staining and DNA, respectively.<br><br>The model has potential for assessing dentition anatomy and fluid flow on the efficacy of antimicrobial efficacy against localized SPB and may be amenable to the plaque index clinical evaluation.},
}
@article {pmid35602061,
year = {2022},
author = {Cheng, C and Yan, X and Liu, B and Jiang, T and Zhou, Z and Guo, F and Zhang, Q and Li, C and Fang, T},
title = {SdiA Enhanced the Drug Resistance of Cronobacter sakazakii and Suppressed Its Motility, Adhesion and Biofilm Formation.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {901912},
doi = {10.3389/fmicb.2022.901912},
pmid = {35602061},
issn = {1664-302X},
abstract = {Cronobacter sakazakii is a common foodborne pathogen, and the mortality rate of its infection is as high as 40-80%. SdiA acts as a quorum sensing regulator in many foodborne pathogens, but its role in C. sakazakii remains unclear. Here, we further determined the effect of the sdiA gene in C. sakazakii pathogenicity. The SdiA gene in C. sakazakii was knocked out by gene editing technology, and the biological characteristics of the ΔsdiA mutant of C. sakazakii were studied, followed by transcriptome analysis to elucidate its effects. The results suggested that SdiA gene enhanced the drug resistance of C. sakazakii but diminished its motility, adhesion and biofilm formation ability and had no effect on its growth. Transcriptome analysis showed that the ΔsdiA upregulated the expression levels of D-galactose operon genes (including dgoR, dgoK, dgoA, dgoD and dgoT) and flagella-related genes (FliA and FliC) in C. sakazakii and downregulated the expression levels of related genes in the type VI secretion system (VasK gene was downregulated by 1.53-fold) and ABC transport system (downregulated by 1.5-fold), indicating that SdiA gene was related to the physiological metabolism of C. sakazakii. The results were useful for clarifying the pathogenic mechanism of C. sakazakii and provide a theoretical basis for controlling bacterial infection.},
}
@article {pmid35601098,
year = {2022},
author = {Rosca, AS and Castro, J and Sousa, LGV and França, A and Cavaleiro, C and Salgueiro, L and Cerca, N},
title = {Six Bacterial Vaginosis-Associated Species Can Form an In Vitro and Ex Vivo Polymicrobial Biofilm That Is Susceptible to Thymbra capitata Essential Oil.},
journal = {Frontiers in cellular and infection microbiology},
volume = {12},
number = {},
pages = {824860},
doi = {10.3389/fcimb.2022.824860},
pmid = {35601098},
issn = {2235-2988},
abstract = {Bacterial vaginosis (BV) is associated with serious gynaecologic and obstetric complications. The hallmark of BV is the presence of a polymicrobial biofilm on the vaginal epithelium, but BV aetiology is still a matter of debate. We have previously developed an in vitro biofilm model that included three BV-associated species, but, up to now, no studies are available whereby more bacterial species are grown together to better mimic the in vivo situation. Herein, we characterized the first polymicrobial BV biofilm consisting of six cultivable BV-associated species by using both in vitro and ex vivo vaginal tissue models. Both models revealed that the six species were able to incorporate the polymicrobial biofilm, at different bacterial concentrations. As it has been thought that this polymicrobial biofilm may increase the survival of BV-associated species when exposed to antibiotics, we also assessed if the Thymbra capitata essential oil (EO), which has recently been shown to be highly bactericidal against several Gardnerella species, could maintain its anti-biofilm activity against this polymicrobial biofilm. Under our experimental conditions, T. capitata EO exhibited a high antibacterial effect against polymicrobial biofilms, in both tested models, with a significant reduction in the biofilm biomass and the number of culturable cells. Overall, this study shows that six BV-associated species can grow together and form a biofilm both in vitro and when using an ex vivo model. Moreover, the data obtained herein should be considered in further applications of T. capitata EO as an antimicrobial agent fighting BV.},
}
@article {pmid35600163,
year = {2022},
author = {Pan, T and Liu, FS and Lin, H and Zhou, Y},
title = {Anti-biofilm studies of synthetic imidazolium salts on dental biofilm in vitro.},
journal = {Journal of oral microbiology},
volume = {14},
number = {1},
pages = {2075309},
doi = {10.1080/20002297.2022.2075309},
pmid = {35600163},
issn = {2000-2297},
abstract = {Objective: Biofilm formation under cariogenic conditions contributes to dental caries development, in which Streptococcus mutans (S. mutans) is regarded as the major cariogenic bacteria. Here, we synthesized a series of imidazolium salts. Their properties of antimicrobial and anti-biofilm were investigated.<br><br>Methods: The microdilution method crystal violet staining, and cell counting Kit-8 assay were used to screen imidazolium salts. Then, the bacterial composition in multi-species biofilm composed of S. mutans, Actinomyces naeslundii, and Streptococcus gordonii was quantified by quantitative PCR. The exopolysaccharide and morphology of the structure of multi-species biofilm were further observed by confocal laser scanning microscopy and scanning electron microscope, respectively.<br><br>Results: Imidazolium salts exhibited highly antimicrobial activity against oral pathogens, especially for S. mutans . Compounds with ortho-diisopropyl and para-methoxyl on N-moieties as well as bearing ancenaphthyl skeleton (C5) showed the lowest cytotoxicity and most efficient anti-biofilm activity. C5 inhibited approximately 50% of multi-species biofilm at 0.98 μg/mL. Notably, C5 resulted in 98.97% live S. mutans and 77.65% A. naeslundii decreased. Furthermore, the exopolysaccharide was reduced by 88%, along with a sparse and scattered microstructure.<br><br>Conclusion: The imidazolium salts present low cytotoxicity and remarkable antimicrobial activity against S. mutans in multi-species biofilm, suggesting that they may have a great potential in anti-biofilm clinical applications.},
}
@article {pmid35598875,
year = {2022},
author = {Abbott, C and Grout, E and Morris, T and Brown, HL},
title = {Cutibacterium acnes biofilm forming clinical isolates modify the formation and structure of Staphylococcus aureus biofilms, increasing their susceptibility to antibiotics.},
journal = {Anaerobe},
volume = {},
number = {},
pages = {102580},
doi = {10.1016/j.anaerobe.2022.102580},
pmid = {35598875},
issn = {1095-8274},
abstract = {Cutibacterium acnes (formally Propionibacterium acnes) is frequently identified within surgical device related infections. It is often co-isolated from infection sites with other opportunistic pathogens. Recent studies have demonstrated that C. acnes is able to form biofilms and when co-cultured with Staphylococcus spp. both inhibitory and stimulatory effects have been reported across several studies. Here, we investigated the biofilm-forming ability of 100 clinical C. acnes isolates from various infection sites in human patients, both deep tissue and superficial, followed by an investigation of how the supernatants of C. acnes cultures influenced the attachment and maturation of S. aureus NCTC 6571 biofilms. All of the C. acnes isolates were able to form biofilms in vitro, although biofilm biomass varied between isolates. Nineteen isolates were weakly adherent, 33 were moderately adherent and the majority (48) showed strong adherence. The presence of C. acnes sterile supernatants reduced the biomass of S. aureus cultures, with a > 90% reduction observed in the presence of several of the C. acnes isolates. We observed that this decrease was not due to C. acnes affecting S. aureus viability, nor due to the presence of propionic acid. Biofilm maturation was however delayed over a 24-hour period as was biofilm surface structure, although initial (up to 8 h) surface attachment was not affected. We hypothesis that this defective biofilm maturation is the cause of the observed biomass decrease. In turn, these altered biofilms showed a greater susceptibility to antibiotic treatments. In contrast the presence of C. acnes supernatant in planktonic (defined as a free moving, non-surface attached population within the liquid column) S. aureus cultures increased antibiotic tolerance, via a currently undefined mechanism. This study suggests that complex interactions between C. acnes and other opportunistic pathogens are likely to exist during colonisation and infection events. Further investigation of these interactions may lead to increased treatment options and a better prognosis for patients.},
}
@article {pmid35598240,
year = {2022},
author = {Yadav, J and Das, S and Singh, S and Jyoti, A and Srivastava, VK and Sharma, V and Kumar, S and Kumar, S and Kaushik, S},
title = {Deciphering the role of S-adenosyl homocysteine nucleosidase in quorum sensing mediated biofilm formation.},
journal = {Current protein &amp; peptide science},
volume = {},
number = {},
pages = {},
doi = {10.2174/1389203723666220519152507},
pmid = {35598240},
issn = {1875-5550},
abstract = {S-adenosylhomocysteine nucleosidase (MTAN) is a protein that plays a crucial role in several pathways of bacteria that are essential for its survival and pathogenesis. In addition to the role of MTAN in methyl-transfer reactions, methionine biosynthesis, and polyamine synthesis, MTAN is also involved in bacterial quorum sensing (QS). In QS, chemical signaling autoinducer (AI) secreted by bacteria assists cell to cell communication and is regulated in a cell density-dependent manner. They play a significant role in the formation of bacterial biofilm. MTAN plays a major role in the synthesis of these autoinducers. Signaling molecules secreted by bacteria i.e. AI-1 is recognized as acylated homoserine lactones (AHL) that function as signaling molecules within bacteria. QS enables bacteria to establish physical interactions leading to biofilm formation. The formation of biofilm is a primary reason for the development of multidrug-resistant properties in pathogenic bacteria like Enterococcus faecalis (E. faecalis). In this regard, inhibition of E. faecalis MTAN (EfMTAN) will block the QS and alter the bacterial biofilm formation. In addition to this, it will also block methionine biosynthesis and many other critical metabolic processes. It should also be noted that inhibition of EfMTAN will not have any effect on human beings as this enzyme is not present in humans. This review provides a comprehensive overview of the structural-functional relationship of MTAN. We have also highlighted the current status, enigmas that warrant further studies, and the prospects for identifying potential inhibitors of EfMTAN for the treatment of E. faecalis infections. In addition to this, we have also reported structural studies of EfMTAN using homology modeling and highlighted the putative binding sites of the protein.},
}
@article {pmid35598180,
year = {2022},
author = {Gregory, ER and Bakhaider, RF and Gomez, GF and Huang, R and Moser, EAS and Gregory, RL},
title = {Evaluating hop extract concentrations found in commercial beer to inhibit Streptococcus mutans biofilm formation.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/jam.15632},
pmid = {35598180},
issn = {1365-2672},
abstract = {AIMS: The purpose of this study was to compare the effect of hop extracts with diverse β-acid concentrations on Streptococcus mutans biofilm formation.<br><br>METHODS AND RESULTS: Ten different hop extracts, with α-acid concentrations similar to those found in commercial beer products and β-acid concentrations ranging from 2.6 to 8.1%, were added to distilled water to make standardized concentrations. S. mutans isolates were treated with hop extract dilutions varying from 1:2 to 1:256. The minimum inhibitory, minimum bactericidal, and minimum biofilm inhibitory concentrations were determined and the optical density was evaluated. Live/dead staining confirmed the bactericidal effects. Biofilm formation of several strains of S. mutans was significantly inhibited by hop extract dilutions of 1:2, 1:4, 1:8, 1:16, and 1:32. Strong negative correlations were observed between α- and β-acid concentrations of the hop extracts and S. mutans total growth and biofilm formation.<br><br>CONCLUSIONS: The use of hop extracts prepared similarly to commercial beer decreased S. mutans biofilm formation.<br><br>The inclusion of hops in the commercial beer products may provide beneficial health effects. Further studies are warranted to determine an effect in vivo on the development of dental caries.},
}
@article {pmid35597812,
year = {2022},
author = {Stabnikova, O and Stabnikov, V and Marinin, A and Klavins, M and Vaseashta, A},
title = {The role of microplastics biofilm in accumulation of trace metals in aquatic environments.},
journal = {World journal of microbiology &amp; biotechnology},
volume = {38},
number = {7},
pages = {117},
pmid = {35597812},
issn = {1573-0972},
abstract = {Microplastics are one of the major contaminants of aquatic nature where they can interact with organic and inorganic pollutants, including trace metals, and adsorb them. At the same time, after the microplastics have entered the aquatic environments, they are quickly covered with a biofilm - microorganisms which are able to produce extracellular polymeric substances (EPS) that can facilitate sorption of trace metals from surrounding water. The microbial community of biofilm contains bacteria which synthesizes EPS with antimicrobial activity making them more competitive than other microbial inhabitants. The trace metal trapping by bacterial EPS can inhibit the development of certain microorganisms, therefore, a single microparticle participates in complex interactions of the diverse elements surrounding it. The presented review aims to consider the variety of interactions associated with the adsorption of trace metal ions on the surface of microplastics covered with biofilm, the fate of such microplastics and the ever-increasing risk to the environment caused by the combination of these large-scale pollutants - microplastics and trace metals. Since aquatic pollution problems affect the entire planet, strict regulation of the production, use, and disposal of plastic materials is needed to mitigate the effects of this emerging pollutant and its complexes could have on the environment and human health.},
}
@article {pmid35597221,
year = {2022},
author = {Wang, N and Feng, Y and Li, Y and Zhang, L and Liu, J and Li, N and He, W},
title = {Effects of ammonia on electrochemical active biofilm in microbial electrolysis cells for synthetic swine wastewater treatment.},
journal = {Water research},
volume = {219},
number = {},
pages = {118570},
doi = {10.1016/j.watres.2022.118570},
pmid = {35597221},
issn = {1879-2448},
abstract = {When facing wastewater with high organic and ammonia, e. g. swine wastewater, microbial electrolysis cell (MEC) is emerging for energy extraction as hydrogen and methane. However, the effects of highly concentrated ammonia on MEC haven't been fully evaluated. In this study, single-chamber MECs were operated with acetate and sucrose as substrates under various ammonia concentrations. The current generally increased with ammonia loading from 80 to 3000 mg L-1. Yet, the substrate consumption in MECs was inhibited with ammonia concentrations above 1000 mg L-1. As a combined result, the energy recovery efficiency of MECs was stable. The electrochemical activity of anode biofilm reached the peak under 1000 mg L-1 ammonia and was restricted under higher ammonia loadings. Under neutral pH, the NH4+ increases the cell membrane permeability, which benefited the electrochemical activity of exoelectrogens to a proper extent. Nevertheless, the toxic ammonia also accelerated the anode biomass loss and stimulated the extracellular polymeric substance (EPS) secretion. Due to the current increase, the abundance of exoelectrogens generally raised with ammonia loading from 80 to 3000 mg L-1. However, except for anode biomass loss, the carbon and methane metabolism pathways were inhibited in acetate-fed MEC, while the glycolysis acted as the rate-limiting step for substrate degradation in sucrose-fed conditions. This study systematically examined the influences of high ammonia loading on MEC performances, bio-community and anode electrochemical activities, and evaluated practical feasibility and application inch of MECs for the energy recovery and pollutant removal of high concentration organic and ammonia wastewater.},
}
@article {pmid35594987,
year = {2022},
author = {Cobrado, L and Ramalho, P and Ricardo, E and Fernandes, ÂR and Azevedo, MM and Rodrigues, AG},
title = {Efficacy assessment of different time-cycles of nebulized hydrogen peroxide against bacterial and yeast biofilm.},
journal = {The Journal of hospital infection},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.jhin.2022.05.010},
pmid = {35594987},
issn = {1532-2939},
abstract = {BACKGROUND: The prevention of healthcare-associated infections requires a continuous effort. In order to achieve better practical results, the control of environmental microbial biofilms with effective disinfection strategies should be addressed.<br><br>AIM: This study aims to test the efficacy of different time-cycles of nebulized H2O2 against bacterial and yeast dry biofilm.<br><br>METHODS: The efficacy of a standard cycle (SC) and of a fast cycle (FC) of nebulized H2O2 was compared. Microbial biofilms were previously grown on different material coupons. The biofilm metabolic activity was determined by XTT assay and the biofilm total biomass by crystal violet assay.<br><br>FINDINGS: Regarding the efficacy of nebulized H2O2 against biofilms, the mean reduction of metabolic activity of the SC was 55.2% (±19.4%), comparing to a reduction of 50.4% (±17.7%) of the FC. The mean reduction of total biomass of the SC was 45.5% (±22.7%), versus 46.7% (±21.7%) of the FC. No statistical significant differences were found when comparing the tested cycles and distinct materials.<br><br>CONCLUSION: H2O2 nebulization was found to exhibit a good efficacy against healthcare-associated microbial dry biofilms. Moreover, similar efficacies were found between the tested cycles.},
}
@article {pmid35594757,
year = {2022},
author = {Kumar, M and Kumar, R and Chaudhary, DR and Jha, B},
title = {An appraisal of early stage biofilm-forming bacterial community assemblage and diversity in the Arabian Sea, India.},
journal = {Marine pollution bulletin},
volume = {180},
number = {},
pages = {113732},
doi = {10.1016/j.marpolbul.2022.113732},
pmid = {35594757},
issn = {1879-3363},
abstract = {The community composition and distribution of early-stage (24 h) biofilm-forming bacteria on two different surfaces (glass slide and polystyrene plastic slide) at three different locations (Diu, Alang and Sikka) were studied using a culture-dependent and next-generation sequencing (NGS) approach in the Arabian Sea, Gujarat, India. The most dominant phyla observed using the NGS approach were the Proteobacteria among the sampling sites. Gammaproteobacteria class dominated both the surfaces among the sites and accounted for 46.7% to 89.2% of total abundance. The culture-dependent analysis showed Proteobacteria and Firmicutes as the dominant phyla on the surfaces within the sampling sites. During the initial colonization, hydrocarbon-degrading bacterial strains have also attached to the surfaces. The outcome of this study would be of great importance for targeting the early stage biofilm-forming and hydrocarbon-degrading bacterial isolates may help to degrade plastic in the marine environment.},
}
@article {pmid35594665,
year = {2022},
author = {Liu, A and Lin, W and Ming, R and Guan, W and Wang, X and Hu, N and Ren, Y},
title = {Stability of 28 typical prescription drugs in sewer systems and interaction with the biofilm bacterial community.},
journal = {Journal of hazardous materials},
volume = {436},
number = {},
pages = {129142},
doi = {10.1016/j.jhazmat.2022.129142},
pmid = {35594665},
issn = {1873-3336},
abstract = {Identifying the attenuation characteristics of drugs in sewage and sewers is one of the important factors to improve the accuracy of wastewater-based epidemiology (WBE) application. In this study, 28 drugs including antidepressants, cardiovascular drugs, antihistamines, anticonvulsants and some of their human metabolites were chosen as the targets to study the hydrolysis, adsorption, and biodegradation at different temperatures in sewage and sewers. The interaction between drugs degradation and community structure of biofilm was also investigated. In the simulated sewers, the removal percentages of 12 parent or drug metabolites are 0-20%, such as demethylvenlafaxine, fluvoxamine, etc., which are highly stable chemicals and suitable to be chosen as biomarkers for WBE back-calculation under appropriate circumstances. Fourteen drugs including venlafaxine and citalopram have removal percentages of 20-60%. While paroxetine and sertraline, with removal percentage of 100%, are the most unstable and cannot be used as biomarkers. Among the 28 drugs, there are 25 drugs that have a higher loss rate in the aerobic sewer than that in the anaerobic sewer in this study. During drug exposure in anaerobic biofilms, species abundance first decreased and then increased. Species abundance and diversity in aerobic biofilm generally showed a decreasing trend. In addition, Proteobacteria and Spirochaetota were the dominant phyla in both sewers.},
}
@article {pmid35593953,
year = {2022},
author = {Ray, S and Jin, JO and Choi, I and Kim, M},
title = {Cell-Free Supernatant of Bacillus thuringiensis Displays Anti-Biofilm Activity Against Staphylococcus aureus.},
journal = {Applied biochemistry and biotechnology},
volume = {},
number = {},
pages = {},
pmid = {35593953},
issn = {1559-0291},
support = {2020 R1A6A1A03044512//Innovative Research Group Project of the National Natural Science Foundation of China/ ; },
abstract = {Staphylococcus aureus is an important bacterial pathogen responsible for biofilm formation in medical devices. Due to the increasing antibiotic resistance of S. aureus, it is necessary to search for new anti-biofilm agents. In this study, the cell-free supernatant of Bacillus thuringiensis inhibited biofilm formation up to 93% and dispersed biofilms up to 83% without affecting the growth of S. aureus. The ethyl acetate extract of B. thuringiensis cell-free supernatant exhibited a dose-dependent anti-biofilm activity against S. aureus with the biofilm inhibition concentration ranging from 8 to 64 µg/mL. Scanning electron microscopy revealed that the cell-free supernatant extract of B. thuringiensis resulted in a significant reduction in S. aureus biofilms. The ethyl acetate extract of cell-free supernatant of B. thuringiensis was found to contain various compounds with structural similarity to known anti-biofilm compounds. In particular, squalene, cinnamic acid derivatives, and eicosapentaene seem to act synergistically against S. aureus biofilms. Hence, B. thuringiensis cell-free supernatant proved to be effective against S. aureus biofilms. The results clearly show the potential of natural molecules produced by B. thuringiensis as alternative therapies with anti-biofilm activity instead of bactericidal properties.},
}
@article {pmid35591562,
year = {2022},
author = {Sarfraz, S and Mäntynen, PH and Laurila, M and Suojanen, J and Saarnio, J and Rossi, S and Horelli, J and Kaakinen, M and Leikola, J and Reunanen, J},
title = {Effect of Surface Tooling Techniques of Medical Titanium Implants on Bacterial Biofilm Formation In Vitro.},
journal = {Materials (Basel, Switzerland)},
volume = {15},
number = {9},
pages = {},
doi = {10.3390/ma15093228},
pmid = {35591562},
issn = {1996-1944},
support = {243032491//Academy of Finland/ ; },
abstract = {The aim of this study was to assess the biofilm formation of Streptococcus mutans, Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli on titanium implants with CAD-CAM tooling techniques. Twenty specimens of titanium were studied: Titanium grade 2 tooled with a Planmeca CAD-CAM milling device (TiGrade 2), Ti6Al4V grade 5 as it comes from CAD-DMLS device (computer aided design-direct metal laser sintering device) (TiGrade 5), Ti6Al4V grade 23 as it comes from a CAD-CAM milling device (TiGrade 23), and CAD-DMLS TiGrade 5 polished with an abrasive disc (TiGrade 5 polished). Bacterial adhesion on the implants was completed with and without saliva treatment to mimic both extraoral and intraoral surgical methods of implant placement. Five specimens/implant types were used in the bacterial adhesion experiments. Autoclaved implant specimens were placed in petri plates and immersed in saliva solution for 30 min at room temperature and then washed 3× with 1× PBS. Bacterial suspensions of each strain were made and added to the specimens after saliva treatment. Biofilm was allowed to form for 24 h at 37 °C and the adhered bacteria was calculated. Tooling techniques had an insignificant effect on the bacterial adhesion by all the bacterial strains studied. However, there was a significant difference in biofilm formation between the saliva-treated and non-saliva-treated implants. Saliva contamination enhanced S. mutans, S. aureus, and E. faecalis adhesion in all material types studied. S. aureus was found to be the most adherent strain in the saliva-treated group, whereas E. coli was the most adherent strain in the non-saliva-treated group. In conclusion, CAD-CAM tooling techniques have little effect on bacterial adhesion. Saliva coating enhances the biofilm formation; therefore, saliva contamination of the implant must be minimized during implant placement. Further extensive studies are needed to evaluate the effects of surface treatments of the titanium implant on soft tissue response and to prevent the factors causing implant infection and failure.},
}
@article {pmid35591238,
year = {2022},
author = {Nakagawa, R and Saito, K and Kanematsu, H and Miura, H and Ishihara, M and Barry, DM and Kogo, T and Ogawa, A and Hirai, N and Hagio, T and Ichino, R and Ban, M and Yoshitake, M and Zimmermann, S},
title = {Impedance Characteristics of Monolayer and Bilayer Graphene Films with Biofilm Formation and Growth.},
journal = {Sensors (Basel, Switzerland)},
volume = {22},
number = {9},
pages = {},
doi = {10.3390/s22093548},
pmid = {35591238},
issn = {1424-8220},
abstract = {Biofilms are the result of bacterial activity. When the number of bacteria (attached to materials' surfaces) reaches a certain threshold value, then the bacteria simultaneously excrete organic polymers (EPS: extracellular polymeric substances). These sticky polymers encase and protect the bacteria. They are called biofilms and contain about 80% water. Other components of biofilm include polymeric carbon compounds such as polysaccharides and bacteria. It is well-known that biofilms cause various medical and hygiene problems. Therefore, it is important to have a sensor that can detect biofilms to solve such problems. Graphene is a single-atom-thick sheet in which carbon atoms are connected in a hexagonal shape like a honeycomb. Carbon compounds generally bond easily to graphene. Therefore, it is highly possible that graphene could serve as a sensor to monitor biofilm formation and growth. In our previous study, monolayer graphene was prepared on a glass substrate by the chemical vapor deposition (CVD) method. Its biofilm forming ability was compared with that of graphite. As a result, the CVD graphene film had the higher sensitivity for biofilm formation. However, the monolayer graphene has a mechanical disadvantage when used as a biofilm sensor. Therefore, for this new research project, we prepared bilayer graphene with high mechanical strength by using the CVD process on copper substrates. For these specimens, we measured the capacitance component of the specimens' impedance. In addition, we have included a discussion about the possibility of applying them as future sensors for monitoring biofilm formation and growth.},
}
@article {pmid35589849,
year = {2022},
author = {Giri, AK and Jena, B and Biswal, B and Pradhan, AK and Arakha, M and Acharya, S and Acharya, L},
title = {Green synthesis and characterization of silver nanoparticles using Eugenia roxburghii DC. extract and activity against biofilm-producing bacteria.},
journal = {Scientific reports},
volume = {12},
number = {1},
pages = {8383},
pmid = {35589849},
issn = {2045-2322},
abstract = {The green synthesis of silver nanoparticles (AgNPs) and their applications have attracted many researchers as the AgNPs are used effectively in targeting specific tissues and pathogenic microorganisms. The purpose of this study is to synthesize and characterize silver nanoparticles from fully expanded leaves of Eugenia roxburghii DC., as well as to test their effectiveness in inhibiting biofilm production. In this study, at 0.1 mM concentration of silver nitrate (AgNO3), stable AgNPs were synthesized and authenticated by monitoring the color change of the solution from yellow to brown, which was confirmed with spectrophotometric detection of optical density. The crystalline nature of these AgNPs was detected through an X-Ray Diffraction (XRD) pattern. AgNPs were characterized through a high-resolution transmission electron microscope (HR-TEM) to study the morphology and size of the nanoparticles (NPs). A new biological approach was undertaken through the Congo Red Agar (CRA) plate assay by using the synthesized AgNPs against biofilm production. The AgNPs effectively inhibit biofilm formation and the biofilm-producing bacterial colonies. This could be a significant achievement in contending with many dynamic pathogens.},
}
@article {pmid35586693,
year = {2022},
author = {Sun, Y and Sun, F and Feng, W and Wang, Q and Liu, F and Xia, P and Qiu, X},
title = {Luteolin Inhibits the Biofilm Formation and Cytotoxicity of Methicillin-Resistant Staphylococcus aureus via Decreasing Bacterial Toxin Synthesis.},
journal = {Evidence-based complementary and alternative medicine : eCAM},
volume = {2022},
number = {},
pages = {4476339},
doi = {10.1155/2022/4476339},
pmid = {35586693},
issn = {1741-427X},
abstract = {Owing to the fact that luteolin has antibacterial activity against Staphylococcus aureus (S. aureus) and methicillin-resistant S. aureus (MRSA), its specific mechanism in MRSA is worthy of investigation, which is the focus of this study. Initially, the collected S. aureus strains were treated with luteolin. Then, the minimum inhibitory concentration (MIC) of luteolin against the S. aureus strains was measured by the broth microdilution. The growth curves, biofilm formation, and cytotoxicity of treated S. aureus were detected using a microplate reader. The live and dead bacteria were evaluated using confocal laser scanning microscopy, the bacterial morphology was observed using scanning electron microscopy, and the S. aureus colony-forming unit (CFU) numbers were assessed. The levels of alpha hemolysin (α-hemolysin), delta hemolysin (δ-hemolysin), and hlaA were detected via western blot and RT-PCR. The mortality of mouse model with S. aureus systemic infection was analyzed, and the levels of IL-6, IL-8, IL-10, and TNF-α were quantitated using ELISA. Concretely, the MIC of luteolin against MRSA N315 was 64 μg/mL. Luteolin at 16 μg/mL did not affect the growth of MRSA N315, but inhibited the biofilm formation and CFU, and promoted the morphological changes and death of MRSA N315. Luteolin decreased the cytotoxicity and the levels of α-hemolysin, δ-hemolysin, and hlaA in MRSA N315, elevated MRSA-reduced mice survival rate, and differentially modulated the inflammatory cytokine levels in MRSA-infected mice. Collectively, luteolin inhibits biofilm formation and cytotoxicity of MRSA via blocking the bacterial toxin synthesis.},
}
@article {pmid35584310,
year = {2022},
author = {Costa, RC and Bertolini, M and Costa Oliveira, BE and Nagay, BE and Dini, C and Benso, B and Klein, MI and Barāo, VAR and Souza, JGS},
title = {Polymicrobial biofilms related to dental implant diseases: unravelling the critical role of extracellular biofilm matrix.},
journal = {Critical reviews in microbiology},
volume = {},
number = {},
pages = {1-21},
doi = {10.1080/1040841X.2022.2062219},
pmid = {35584310},
issn = {1549-7828},
abstract = {Biofilms are complex tri-dimensional structures that encase microbial cells in an extracellular matrix comprising self-produced polymeric substances. The matrix rich in extracellular polymeric substance (EPS) contributes to the unique features of biofilm lifestyle and structure, enhancing microbial accretion, biofilm virulence, and antimicrobial resistance. The role of the EPS matrix of biofilms growing on biotic surfaces, especially dental surfaces, is largely unravelled. To date, there is a lack of a broad overview of existing literature concerning the relationship between the EPS matrix and the dental implant environment and its role in implant-related infections. Here, we discuss recent advances in the critical role of the EPS matrix on biofilm growth and virulence on the dental implant surface and its effect on the etiopathogenesis and progression of implant-related infections. Similar to other biofilms associated with human diseases/conditions, EPS-enriched biofilms on implant surfaces promote microbial accumulation, microbiological shift, cross-kingdom interaction, antimicrobial resistance, biofilm virulence, and, consequently, peri-implant tissue damage. But intriguingly, the protagonism of EPS role on implant-related infections and the development of matrix-target therapeutic strategies has been neglected. Finally, we highlight the need for more in-depth analyses of polymicrobial interactions within EPS matrix and EPS-targeting technologies' rationale for disrupting the complex biofilm microenvironment with more outstanding translation to implant applications in the near future.},
}
@article {pmid35579972,
year = {2022},
author = {Bi, H and Deng, R and Liu, Y},
title = {Linezolid decreases Staphylococcus aureus biofilm formation by affecting the IcaA and IcaB proteins.},
journal = {Acta microbiologica et immunologica Hungarica},
volume = {},
number = {},
pages = {},
doi = {10.1556/030.2022.01689},
pmid = {35579972},
issn = {1588-2640},
abstract = {Background: The ica gene of Staphylococcus aureus (S. aureus) plays a vital role in its growth and biofilm formation. Among them, IcaA and IcaB are critical proteins for synthesizing extracellular polysaccharides and biofilms in S. aureus. To investigate whether the formation of S. aureus biofilms can be inhibited through the IcaA and IcaB proteins by the presence of linezolid.<br><br>Methods: The icaA and icaB genes of S. aureus ATCC 25923 were silenced by homologous recombination. The critical roles of icaA and icaB in S. aureus were analysed by observing the growth curve and biofilm formation after linezolid treatment. Then, the effect of linezolid on the morphology of S. aureus was observed by scanning electron microscopy. Finally, the potential binding ability of linezolid to Ica proteins was predicted by molecular docking.<br><br>Results: The icaA- and icaB-silenced strains were successfully constructed, and the sensitivity of S. aureus to linezolid was decreased after icaA and icaB silencing. Scanning electron microscopy showed that linezolid caused invagination of the S. aureus surface and reduced the production of biofilms. Molecular docking results showed that linezolid could bind to IcaA and IcaB proteins.<br><br>Conclusion: IcaA and IcaB are potential targets of linezolid in inhibiting the biofilm formation of S. aureus (ATCC 25923).},
}
@article {pmid35579742,
year = {2022},
author = {Bhadra, S and Chettri, D and Kumar Verma, A},
title = {Biosurfactants: Secondary Metabolites Involved in the Process of Bioremediation and Biofilm Removal.},
journal = {Applied biochemistry and biotechnology},
volume = {},
number = {},
pages = {},
pmid = {35579742},
issn = {1559-0291},
abstract = {The search for environmentally friendly methods to remove persistent substances such as organic pollutants and sessile communities such as biofilms that severely affect the environment and human health resulted in biosurfactant discovery. Owing to their low level of toxicity and high biodegradability, biosurfactants are increasingly preferred to be used for removal of pollutants from nature. These amphipathic molecules can be synthesized inexpensively, employing cheap substrates such as agricultural and industrial wastes. Recent progress has been made in identifying various biosurfactants that can be used to remove organic pollutants and harmful microbial aggregates, as well as novel microbial strains that produce these surface-active molecules to survive in a hydrocarbon-rich environment. This review focuses on the identification and understanding the role of biosurfactants and the microorganisms involved in the removal of biofilms and remediation of xenobiotics and various types of hydrocarbons such as crude oil, aromatic hydrocarbons, n-alkanes, aliphatic hydrocarbons, asphaltenes, naphthenes, and other petroleum products. This property of biosurfactant is very important as biofilms are of great concern due to their impact on the environment, public health, and industries worldwide. This work also includes several advanced molecular methods that can be used to enhance the production of biosurfactants by the microorganisms studied.},
}
@article {pmid35579148,
year = {2022},
author = {Saraswathi, N and Girigoswami, K and Divya, KC and Kumar, SG and Girigoswami, A},
title = {Degree of Gelatination on Ag-Nanoparticles to Inactivate Multi-drug Resistant Bacterial Biofilm Isolated from Sewage Treatment Plant.},
journal = {Current drug delivery},
volume = {},
number = {},
pages = {},
doi = {10.2174/1567201819666220509160432},
pmid = {35579148},
issn = {1875-5704},
abstract = {INTRODUCTION: Overuse and improper dosage of antibiotics have generated antimicrobial resistance (AMR) worldwide. Pseudomonas aeruginosa (PA), a well-known bacterial strain can establish MDR leading to a variety of infections in humans. Furthermore, these PA strains hold the ability to form biofilms by generating extracellular polymeric substances on the surface of medical tools and critical care units. To supersede the infectious effect of MDR organisms, silver nanoparticles have been known to be the choice.<br><br>MATERIALS AND METHODS: Hence, the present study concentrates on the engineering of varying concentrations of gelatin-based polymeric hydrogel embedded with silver nanoparticles (G-AgNPs) for controlled bactericidal activity against MDR PA biofilms. Biofilms formation by MDR PA was confirmed microscopically, and spectroscopy was taken as a tool to characterize and analyze the efficacy at every stage of experiments.<br><br>RESULTS: When MDR PA biofilms were treated with G-AgNPs prepared with 5 % gelatin concentration (AgNP3), they exhibited superior bactericidal activity. Furthermore, a dose-dependent study showed that 800 nM of AgNP3 could inhibit the growth of MDR PA.<br><br>CONCLUSION: Hence it can be concluded that silver nanoparticles synthesized in the presence of 5% gelatin can act as a bactericidal agent in the inactivation of MDR PA biofilms, thereby controlling the infections caused by these biofilms.},
}
@article {pmid35578895,
year = {2022},
author = {Rosca, AS and Castro, J and Sousa, LGV and França, A and Vaneechoutte, M and Cerca, N},
title = {In vitro interactions within a biofilm containing three species found in bacterial vaginosis (BV) support the higher antimicrobial tolerance associated with BV recurrence.},
journal = {The Journal of antimicrobial chemotherapy},
volume = {},
number = {},
pages = {},
doi = {10.1093/jac/dkac155},
pmid = {35578895},
issn = {1460-2091},
support = {//Portuguese Foundation for Science and Technology/ ; PTDC/BIA-MIC/28271/2017//FCT/ ; },
abstract = {BACKGROUND: Bacterial vaginosis (BV), the most common cause of vaginal discharge, is characterized by the presence of a polymicrobial biofilm on the vaginal epithelium, formed primarily by Gardnerella spp., but also other anaerobic species. Interactions between bacteria in multi-species biofilms are likely to contribute to increased virulence and to enhanced antimicrobial tolerance observed in vivo. However, functional studies addressing this question are lacking.<br><br>OBJECTIVES: To gain insights into the role that interactions between BV-associated species in multi-species BV biofilms might have on antimicrobial tolerance, single- and triple-species biofilms formed by Gardnerella vaginalis, Fannyhessea (Atopobium) vaginae and Peptostreptococcus anaerobius were characterized, before and after metronidazole or clindamycin treatment.<br><br>METHODS: Total biofilm biomass, total cells and cfu counts prior to and after antibiotic treatment were first determined. In addition, bacterial populations in the triple-species biofilms were also quantified by quantitative PCR (qPCR) and peptide nucleic acid (PNA) fluorescence in situ hybridization (FISH).<br><br>RESULTS: Despite the effect observed in single-species biofilms, neither metronidazole nor clindamycin was effective in reducing triple-species biofilm biomass. Similar results were obtained when evaluating the number of total or culturable cells. Interestingly, despite differences between strain susceptibilities to antibiotics, the composition of the triple-species biofilms was not strongly affected by antibiotics.<br><br>CONCLUSIONS: Taken together, these results strengthen the idea that, when co-incubated, bacteria can interact synergistically, leading to increased tolerance to antimicrobial therapy, which helps explain the observed clinically high BV recurrence rates.},
}
@article {pmid35576698,
year = {2022},
author = {Das, A and Kundu, S and Gupta, M and Mukherjee, A},
title = {Guar gum propionate-kojic acid films for Escherichia coli biofilm disruption and simultaneous inhibition of planktonic growth.},
journal = {International journal of biological macromolecules},
volume = {211},
number = {},
pages = {57-73},
doi = {10.1016/j.ijbiomac.2022.05.052},
pmid = {35576698},
issn = {1879-0003},
abstract = {Nosocomial bacterial infections associated with biofilms inspire to explore newer bactericidal strategy with eco-friendly biomaterials as sustainable alternatives. In this research work, we successfully developed bio-safe films from kojic acid(KA) and guar gum propionate(GGP) for Escherichia coli biofilm disruption and planktonic cell killing. High DS(degree of substitution = 1.52) GGP was synthesized from guar gum (GG)assisted by chaotropic ions at room-temperature. Biopolymers were routinely characterized in CHN analyzer, FT-IR, TGA and XRD analysis. KA loaded GGP films were prepared by cross-linking the molecules in presence of epichlorhydrin and two different percentages of KA were employed. Film physical and tensile properties were systematically evaluated and optimized. Water vapour permeability (WVP) and tensile strength of final film GGPFK10 were recorded at 0.741 ± 0.09gmm-1kPa-1h-1 and 19.23 MPa. KA release from GGP matrix followed controlled diffusion process. MIC of GGP was 130 μg/mL and zone of inhibition of GGPFK10 was confirmed at 16.1 mm. SEM experiments disclosed the absence of pili-like structures with squeezed and elongated cellular morphology in dead planktonic cells. Disruption of biofilms was experimented in detail by CV assay, fluorescent, light microscopic and SEM studies. The film showed excellent cell-viability on human adult dermal fibroblast (HADF)cell-line. Overall, the biosafe film would be a potent antibacterial device for treating infections against E.coli biofilms and planktonic cells.},
}
@article {pmid35576062,
year = {2022},
author = {Gurler, H and Findik, A and Sezener, MG},
title = {Determination of antibiotic resistance profiles and biofilm production of Staphylococcus spp. isolated from Anatolian water buffalo milk with subclinical mastitis.},
journal = {Polish journal of veterinary sciences},
volume = {25},
number = {1},
pages = {51-59},
doi = {10.24425/pjvs.2022.140840},
pmid = {35576062},
issn = {2300-2557},
mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Biofilms ; Buffaloes ; Cattle ; *Cattle Diseases ; Drug Resistance, Microbial ; Female ; *Mastitis, Bovine ; Milk ; *Staphylococcal Infections/veterinary ; Staphylococcus/genetics ; Staphylococcus aureus ; },
abstract = {Mastitis is one of the most crucial diseases of dairy animals. Especially subclinical mastitis (SCM) has negative impacts on of dairy economy in term of reducing milk quality and quantity also premature culling and cost of therapy. Staphylococci are important etiological agents in SCM. The aim of the study was to investigate the biofilm production and antibiotic resistance profiles of Staphylococcus spp. other than S. aureus isolated from milks of Anatolian water buffalo with subclinical mastitis. Twenty-two coagulase negative staphylococci (CNS) identified phenotypically were also identified with PCR as Staphylococcus spp. other than S. aureus. Biofilm productions were investigated both by Congo Red Agar Method and PCR. The antibiotic resistance profiles of the isolates were determined by Disc Diffusion Method and they were antibiotyped. Only three (13.6%) isolates were biofilm positive both phenotypically and genotypically. All isolates except for two were resistant against at least two antibiotics. Multidrug-resistance among the isolates was low (13.6%). Antibiotyping results showed that the similarities among the strains were between 30-100%. Genotyping of the strains revealed that a genetic heterogeneity was found among CNS isolates and their similarities were between 43% and 93%. In conclusion, CNS isolates identified as subclinical mastitis agents in buffaloes showed a high antibiotic resistance profile especially against oxacillin and vancomycin. Further studies should be conducted to investigate new mechanisms and/or genes responsible for antibiotic resistance in buffaloes.},
}
@article {pmid35575526,
year = {2022},
author = {Ma, Y and Hasan, Z and Huang, J and Chen, J and Ho, CL},
title = {Measuring the Migration and Biofilm Formation of Various Bacteria.},
journal = {Journal of visualized experiments : JoVE},
volume = {},
number = {183},
pages = {},
doi = {10.3791/63595},
pmid = {35575526},
issn = {1940-087X},
abstract = {As microbes that thrive in the host body primarily have adaptive abilities that facilitate their survival, methods for classifying and identifying their nature would be beneficial in facilitating their characterization. Currently, most studies focus only on one specific characterization method; however, the isolation and identification of microorganisms from the host is a continuous process and usually requires several combinatorial characterization methods. Herein, we describe methods of identifying the microbial biofilm-forming ability, the microbial respiration state, and their chemotaxis behavior. The methods are used to identify five microbes, three of which were isolated from the bone tissue of Sprague-Dawley (SD) rats (Corynebacterium stationis, Staphylococcus cohnii subsp. urealyticus, and Enterococcus faecalis) and two from the American Type Culture Collection (ATCC)-Staphylococcus aureus ATCC 25923 and Enterococcus faecalis V583. The microbes isolated from the SD rat bone tissue include the gram-positive microbes. These microbes have adapted to thrive under stressful and nutrient-limiting environments within the bone matrix. This article aims to provide the readers with the specific know-how of determining the nature and behavior of the isolated microbes within a laboratory setting.},
}
@article {pmid35575506,
year = {2022},
author = {Ham, SY and Kim, HS and Cha, E and Lim, T and Byun, Y and Park, HD},
title = {Raffinose Inhibits Streptococcus mutans Biofilm Formation by Targeting Glucosyltransferase.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0207621},
doi = {10.1128/spectrum.02076-21},
pmid = {35575506},
issn = {2165-0497},
abstract = {Streptococcus mutans is a representative biofilm-forming bacterium that causes dental caries through glucosyltransferase (GTF) activity. Glucans are synthesized from sucrose by GTFs and provide binding sites for S. mutans to adhere tightly to the tooth enamel. Therefore, if a novel compound that interferes with GTF function is developed, biofilm formation control in S. mutans would be possible. We discovered that raffinose, an oligosaccharide from natural products, strongly inhibited biofilm formation, GTF-related gene expression, and glucan production. Furthermore, biofilm inhibition on saliva-coated hydroxyapatite discs through the reduction of bacterial adhesion indicated the applicability of raffinose in oral health. These effects of raffinose appear to be due to its ability to modulate GTF activity in S. mutans. Hence, raffinose may be considered an antibiofilm agent for use as a substance for oral supplies and dental materials to prevent dental caries. IMPORTANCE Dental caries is the most prevalent infectious disease and is expensive to manage. Dental biofilms can be eliminated via mechanical treatment or inhibited using antibiotics. However, bacteria that are not entirely removed or are resistant to antibiotics can still form biofilms. In this study, we found that raffinose inhibited biofilm formation by S. mutans, a causative agent of dental caries, possibly through binding to GtfC. Our findings support the notion that biofilm inhibition by raffinose can be exerted by interference with GTF function, compensating for the shortcomings of existing commercialized antibiofilm methods. Furthermore, raffinose is an ingredient derived from natural products and can be safely utilized in humans; it has no smell and tastes sweet. Therefore, raffinose, which can control S. mutans biofilm formation, has been suggested as a substance for oral supplies and dental materials to prevent dental caries.},
}
@article {pmid35575497,
year = {2022},
author = {Shmidov, E and Lebenthal-Loinger, I and Roth, S and Karako-Lampert, S and Zander, I and Shoshani, S and Danielli, A and Banin, E},
title = {PrrT/A, a Pseudomonas aeruginosa Bacterial Encoded Toxin-Antitoxin System Involved in Prophage Regulation and Biofilm Formation.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0118222},
doi = {10.1128/spectrum.01182-22},
pmid = {35575497},
issn = {2165-0497},
abstract = {Toxin-antitoxin (TA) systems are genetic modules that consist of a stable protein-toxin and an unstable antitoxin that neutralizes the toxic effect. In type II TA systems, the antitoxin is a protein that inhibits the toxin by direct binding. Type II TA systems, whose roles and functions are under intensive study, are highly distributed among bacterial chromosomes. Here, we identified and characterized a novel type II TA system PrrT/A encoded in the chromosome of the clinical isolate 39016 of the opportunistic pathogen Pseudomonas aeruginosa. We have shown that the PrrT/A system exhibits classical type II TA characteristics and novel regulatory properties. Following deletion of the prrA antitoxin, we discovered that the system is involved in a range of processes including (i) biofilm and motility, (ii) reduced prophage induction and bacteriophage production, and (iii) increased fitness for aminoglycosides. Taken together, these results highlight the importance of this toxin-antitoxin system to key physiological traits in P. aeruginosa. IMPORTANCE The functions attributed to bacterial TA systems are controversial and remain largely unknown. Our study suggests new insights into the potential functions of bacterial TA systems. We reveal that a chromosome-encoded TA system can regulate biofilm and motility, antibiotic resistance, prophage gene expression, and phage production. The latter presents a thus far unreported function of bacterial TA systems. In addition, with the emergence of antimicrobial-resistant bacteria, especially with the rising of P. aeruginosa resistant strains, the investigation of TA systems is critical as it may account for potential new targets against the resistant strains.},
}
@article {pmid35575383,
year = {2022},
author = {Peng, J and Xie, S and Huang, K and Ran, P and Wei, J and Zhang, Z and Li, X},
title = {Nitric oxide-propelled nanomotors for bacterial biofilm elimination and endotoxin removal to treat infected burn wounds.},
journal = {Journal of materials chemistry. B},
volume = {},
number = {},
pages = {},
doi = {10.1039/d2tb00555g},
pmid = {35575383},
issn = {2050-7518},
abstract = {Biofilm infection is regarded as a major contributing factor to the failure of burn treatment and a persistent inflammatory state delays healing and leads to the formation of chronic wounds. Herein, self-propelled nanomotors (NMs) are proposed to enhance biofilm infiltration, bacterial destruction, and endotoxin clearance to accelerate the healing of infected burn wounds. Janus nanoparticles (NPs) were prepared through partially coating Fe3O4 NPs with polydopamine (PDA) layers, and then polymyxin B (PMB) and thiolated nitric oxide (SNO) donors were separately grafted onto the Janus NPs to obtain IO@PMB-SNO NMs. In response to elevated glutathione (GSH) levels in biofilms, NO generation from one side of the Janus NPs leads to self-propelled motion and deep infiltration into biofilms. The local release of NO could destroy bacteria inside the biofilm, which provides a non-antibiotic antibiofilm approach without the development of drug resistance. In addition to intrinsic antibacterial effects, the PMB grafts preferentially bind with bacteria and the active motion enhances lipopolysaccharide (LPS) clearance and then significantly attenuates the production of inflammatory cytokines and reactive oxide species by macrophages. Partial-thickness burn wounds were established on mice and infected with P. aeruginosa, and NM treatment almost fully destroyed the bacteria in the wounds. IO@PMB-SNO NMs absorb LPS and remove it from the wounds under a magnetic field, which downregulates the interleukin-6 and tumor necrosis factor-α levels in tissues. The infected wounds were completely healed with the deposition and arrangement of collagen fibers and the generation of skin features similar to those of normal skin. Thus, IO@PMB-SNO NMs achieved multiple-mode effects, including GSH-triggered NO release and self-propelled motion, the NO-induced non-antibiotic elimination of biofilms and bacteria, and PMB-induced endotoxin removal. This study offers a feasible strategy, with integrated antibiofilm and anti-inflammatory effects, for accelerating the healing of infected burn wounds.},
}
@article {pmid35575359,
year = {2022},
author = {Xue, R and Chu, X and Yang, F and Liu, Z and Yin, L and Tang, H},
title = {Imidazolium-Based Polypeptide Coating with a Synergistic Antibacterial Effect and a Biofilm-Responsive Property.},
journal = {ACS macro letters},
volume = {11},
number = {3},
pages = {387-393},
doi = {10.1021/acsmacrolett.2c00017},
pmid = {35575359},
issn = {2161-1653},
abstract = {Surface modification with cationic polymer coatings represented an important strategy to address the medical device-related infection issues. However, limited antibacterial activities and high cytotoxicity have hampered their development. Herein, we report a facile method to enhance the surface antibacterial activity by construction of an imidazolium-based polypeptide with fosfomycin counteranions (i.e., S4-PIL-FS). The polypeptide coating displayed a synergistic antibacterial effect from the combination of membrane disruption and inhibition of initial cell wall synthesis, leading to higher in vitro and in vivo surface antibacterial activities than cationic polypeptide or fosfomycin sodium alone. S4-PIL-FS also showed a decrease in the hemolytic ratio and cytotoxicity toward different mammalian cells. Moreover, we observed an interesting biofilm-responsive property of S4-PIL-FS originating from the esterase-induced cleavages of side-chain ester bonds that enabled an antibiofilm property of the cationic polypeptide coating.},
}
@article {pmid35574689,
year = {2022},
author = {Ribeiro Almeida, JC and Merces Bega, JM and Leite, LS and Nascimento de Oliveira, J and Albertin, LL and Matsumoto, T},
title = {Membrane Aerated Biofilm Reactor in Recirculating Aquaculture System for Effluent Treatment.},
journal = {Environmental technology},
volume = {},
number = {},
pages = {1-24},
doi = {10.1080/09593330.2022.2078674},
pmid = {35574689},
issn = {1479-487X},
abstract = {The implementation of fish farming has been increasing worldwide over the last decades, as well the search for alternative production systems and the treatment of their generated effluent. Recirculating Aquaculture System (RAS) is a compact solution for future intensive fish farming. However, few configurations of treatment technologies were tested in RAS, such as systems with a Membrane Aerated Biofilm Reactor (MABR). In this scene, this study aimed to evaluate the RAS effluent treatment efficiency device for intensive Nile tilapia (Oreochromis niloticus) production, the fish species most cultivated worldwide. The novel RAS configuration was composed of a cultivation tank (CT), a Column Settler, and a MABR. The RAS performance was evaluated by pH, temperature, turbidity, dissolved oxygen (DO), total nitrogen (TN), ammonia, nitrite, nitrate, total solids (TS), and chemical oxygen demand (COD). The obtained results in average values for temperature, pH, and DO inside the CT were 25.22 ± 1.88 °C, 7.61 ± 0.33, and 3.80 ± 1.30 mg L-1, respectively, as ideal for tilapias survival. Average removal efficiencies found in the RAS for turbidity, COD, TN, nitrite, nitrate, ammonia, and TS were 50.0, 40.5, 11.7, 40.2, 13.1, 35.0, and 11.4%, respectively. Overall, we observed removals for all parameters studied, with good results, particularly, for COD, turbidity, nitrite, and ammonia. The evaluated system proved an effective alternative for water reuse in RAS capable of maintaining water quality characteristics within the recommended values for fish farming.},
}
@article {pmid35573801,
year = {2022},
author = {Cho, JY and Liu, R and Hsiao, A},
title = {Microbiota-Associated Biofilm Regulation Leads to Vibrio cholerae Resistance Against Intestinal Environmental Stress.},
journal = {Frontiers in cellular and infection microbiology},
volume = {12},
number = {},
pages = {861677},
doi = {10.3389/fcimb.2022.861677},
pmid = {35573801},
issn = {2235-2988},
abstract = {The commensal microbes of the gut microbiota make important contributions to host defense against gastrointestinal pathogens, including Vibrio cholerae, the etiologic agent of cholera. As interindividual microbiota variation drives individual differences in infection susceptibility, we examined both host and V. cholerae gene expression during infection of suckling mice transplanted with different model human commensal communities, including an infection-susceptible configuration representing communities damaged by recurrent diarrhea and malnutrition in cholera endemic areas and a representative infection-resistant microbiota characteristic of healthy individuals. In comparison to colonization of animals with resistant microbiota, animals bearing susceptible microbiota challenged with V. cholerae downregulate genes associated with generation of reactive oxygen/nitrogen stress, while V. cholerae in these animals upregulates biofilm-associated genes. We show that V. cholerae in susceptible microbe infection contexts are more resistant to oxidative stress and inhibitory bile metabolites generated by the action of commensal microbes and that both phenotypes are dependent on biofilm-associated genes, including vpsL. We also show that susceptible and infection-resistant microbes drive different bile acid compositions in vivo by the action of bile salt hydrolase enzymes. Taken together, these findings provide a better understanding of how the microbiota uses multiple mechanisms to modulate the infection-associated host environment encountered by V. cholerae, leading to commensal-dependent differences in infection susceptibility.},
}
@article {pmid35573794,
year = {2022},
author = {Ommen, P and Hansen, L and Hansen, BK and Vu-Quang, H and Kjems, J and Meyer, RL},
title = {Aptamer-Targeted Drug Delivery for Staphylococcus aureus Biofilm.},
journal = {Frontiers in cellular and infection microbiology},
volume = {12},
number = {},
pages = {814340},
doi = {10.3389/fcimb.2022.814340},
pmid = {35573794},
issn = {2235-2988},
abstract = {Treatment of Staphylococcus aureus biofilm infections using conventional antibiotic therapy is challenging as only doses that are sublethal to the biofilm can be administered safely to patients. A potential solution to this challenge is targeted drug delivery. In this study, we tailored an aptamer-targeted liposomal drug delivery system for accumulation and delivery of antibiotics locally in S. aureus biofilm. In our search for a suitable targeting ligand, we identified six DNA aptamers that bound to S. aureus cells in biofilms, and we demonstrated that one of these aptamers could facilitate accumulation of liposomes around S. aureus cells inside the biofilm. Aptamer-targeted liposomes encapsulating a combination of vancomycin and rifampicin were able to eradicate S. aureus biofilm upon 24 h of treatment in vitro. Our results point to that aptamer-targeted drug delivery of antibiotics is a potential new strategy for treatment of S. aureus biofilm infections.},
}
@article {pmid35572854,
year = {2022},
author = {Sun, H and Chan, Y and Li, X and Xu, R and Zhang, Z and Hu, X and Wu, F and Deng, F and Yu, X},
title = {Multi-omics analysis of oral bacterial biofilm on titanium oxide nanostructure modified implant surface: In vivo sequencing-based pilot study in beagle dogs.},
journal = {Materials today. Bio},
volume = {15},
number = {},
pages = {100275},
doi = {10.1016/j.mtbio.2022.100275},
pmid = {35572854},
issn = {2590-0064},
abstract = {Peri-implantitis, the major cause of implant failure, is an inflammatory destructive disease due to the dysbiotic polymicrobial communities at the peri-implant sites. Therefore, it is highly warranted to develop the implant materials with antimicrobial properties and investigate their effects on oral microbiota. However, most of the relevant studies were performed in vitro, and insufficient to provide the comprehensive assessment of the antimicrobial capacity of the implant materials in vivo. Herein, we introduce an innovative approach to evaluate the in vivo antibacterial properties of the most commonly used implant materials, titanium with different nanostructured surfaces, and investigate their antibacterial mechanism via the next-generation sequencing (NGS) technology. We firstly prepared the titanium implants with three different surfaces, i) mechanical polishing (MP), ii) TiO2 nanotubes (NT) and iii) nanophase calcium phosphate embedded to TiO2 nanotubes (NTN), and then characterized them using scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDS), X-ray photoelectron spectroscopy (XPS), confocal laser scanning microscopy (CLSM) and surface hydrophilicity analysis. Afterwards, the implants were placed in the beagle dogs' mouths to replace the pre-extracted premolar and molar teeth for eight weeks through implant surgery. The supra- and sub-mucosal plaques were collected and subjected to 16S rRNA gene/RNA sequencing and data analysis. It was found that the nanostructured surfaces in NT and NTN groups showed significantly increased roughness and decreased water contact angles compared to the MP group, while the XPS data further confirmed the successful modifications of TiO2 nanotubes and the subsequent deposition of nanophase calcium phosphate. Notably, the nanostructured surfaces in NT and NTN groups had limited impact on the diversity and community structure of oral microbiota according to the 16S rRNA sequencing results, and the nanostructures in NTN group could down-regulate the genes associated with localization and locomotion based on Gene Ontology (GO) terms enrichment analysis. Moreover, the differentially expressed genes (DEGs) were associated with microbial metabolism, protein synthesis and bacterial invasion of epithelial cells. Taken together, this study provides a new strategy to evaluate the antibacterial properties of the biomedical materials in vivo via the high-throughput sequencing and bioinformatic approaches, revealing the differences of the composition and functional gene expressions in the supra- and sub-mucosal microbiome.},
}
@article {pmid35572695,
year = {2022},
author = {Li, RJ and Qin, C and Huang, GR and Liao, LJ and Mo, XQ and Huang, YQ},
title = {Phillygenin Inhibits Helicobacter pylori by Preventing Biofilm Formation and Inducing ATP Leakage.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {863624},
doi = {10.3389/fmicb.2022.863624},
pmid = {35572695},
issn = {1664-302X},
abstract = {With the widespread use and abuse of antibiotics, Helicobacter pylori (H. pylori) has become seriously drug resistant. The development of new antibiotics is an important way to solve H. pylori's drug resistance. Screening antibacterial ingredients from natural products is a convenient way to develop new antibiotics. Phillygenin, an effective antibacterial component, was selected from the natural product, forsythia, in this study. Its minimal inhibitory concentration (MIC) for 18 H. pylori strains was 16-32 μg/ml. The minimum bactericidal concentration (MBC) of H. pylori G27 was 128 μg/ml; the higher the drug concentration and the longer the time, the better the sterilization effect. It was non-toxic to gastric epithelial cell (GES)-1 and BGC823 cells at the concentration of 100 μg/ml. It presented a better antibacterial effect on H. pylori in an acidic environment, and after 24 days of induction on H. pylori with 1/4 MIC of phillygenin, no change was found in the MIC of H. pylori. In the mechanism of action, phillygenin could cause ATP leakage and inhibit the biofilm formation; the latter was associated with the regulation of spoT and Hp1174 genes. In addition, phillygenin could regulate the genes of Nhac, caggamma, MATE, MdoB, flagellinA, and lptB, leading to the weakening of H. pylori's acid resistance and virulence, the diminishing of H. pylori's capacity for drug efflux, H. pylori's DNA methylation, the initiation of human immune response, and the ATP leakage of H. pylori, thus accelerating the death of H. pylori. In conclusion, phillygenin was a main ingredient inhibiting H. pylori in Forsythia suspensa, with a good antibacterial activity, high safety, strong specificity, better antibacterial effect under acidic conditions, and low risk of resistance development by H. pylori. Its mechanism of action was mainly associated with inhibiting the biofilm formation and resulting in ATP leakage. In addition, phillygenin was shown to be able to reduce the acid resistance and virulence of H. pylori.},
}
@article {pmid35572468,
year = {2022},
author = {Demir, B and Taylor, A and Broughton, RM and Huang, TS and Bozack, MJ and Worley, SD},
title = {N-halamine surface coating for mitigation of biofilm and microbial contamination in water systems for space travel.},
journal = {Biofilm},
volume = {4},
number = {},
pages = {100076},
doi = {10.1016/j.bioflm.2022.100076},
pmid = {35572468},
issn = {2590-2075},
abstract = {A copolymer termed HASL produced from monomeric units of 2-acrylamido-2-methyl-1-(5-methylhydantoinyl)propane (HA) and of 3-(trimethoxysilyl)propyl methacrylate (SL) has been coated onto stainless steel and Inconel™ substrates, which upon halogenation with either aqueous oxidative chlorine or bromine, became antimicrobial. It has been demonstrated that the halogenated stainless steel and Inconel™ substrates were effective in producing 6 to 7 log inactivations of Staphylococcus aureus and Escherichia coli O157:H7 within about 10 min, and in prevention of Pseudomonas aeruginosa biofilm formation over a period of at least 72 h on the stainless steel substrates. Upon loss of halogen, the HASL coating could be re-charged with aqueous halogen. The HASL coating was easily applied to the substrates via a simple dip-coating method and was reasonably stable to contact with water. Both chlorinated substrates could be loaded with at least 6 × 1016 oxidative Cl atoms per cm2 and maintained a loading of greater than 1 × 1016 chlorine atoms per cm2 for a period of 3-7 days while agitated in aqueous solution. After loss of chlorine to a level below 1 × 1016 atoms per cm2, the substrates could be recharged to the 6 × 1016 Cl atoms per cm2 level for at least 5 times over a 28 day period. The new antimicrobial coating technology has potential for use in a variety of important applications, particularly for water treatment and storage on spacecraft.},
}
@article {pmid35570462,
year = {2022},
author = {Fortune, GT and Oliveira, NM and Goldstein, RE},
title = {Biofilm Growth under Elastic Confinement.},
journal = {Physical review letters},
volume = {128},
number = {17},
pages = {178102},
doi = {10.1103/PhysRevLett.128.178102},
pmid = {35570462},
issn = {1079-7114},
abstract = {Bacteria often form surface-bound communities, embedded in a self-produced extracellular matrix, called biofilms. Quantitative studies of bioflim growth have typically focused on unconfined expansion above solid or semisolid surfaces, leading to exponential radial growth. This geometry does not accurately reflect the natural or biomedical contexts in which biofilms grow in confined spaces. Here, we consider one of the simplest confined geometries: a biofilm growing laterally in the space between a solid surface and an overlying elastic sheet. A poroelastic framework is utilized to derive the radial growth rate of the biofilm; it reveals an additional self-similar expansion regime, governed by the Poisson's ratio of the matrix, leading to a finite maximum radius, consistent with our experimental observations of growing Bacillus subtilis biofilms confined by polydimethylsiloxane.},
}
@article {pmid35569716,
year = {2022},
author = {Rana, MS and Prajapati, SK},
title = {Mixotrophic microalgal-biofilm reactor augmenting biomass and biofuel productivity.},
journal = {Bioresource technology},
volume = {356},
number = {},
pages = {127306},
doi = {10.1016/j.biortech.2022.127306},
pmid = {35569716},
issn = {1873-2976},
abstract = {The present work aimed to evaluate the mixotrophic growth of Chlorella pyrenoidosa in a microalgal-biofilm reactor (MBR) using waste glycerol as an organic carbon source. The biomass productivity of C. pyrenoidosa (10.14 g m-2 d-1) under the mixotrophic mode was remarkably higher than that observed during the phototrophic mode (4.16 g m-2 d-1), under similar incubation conditions. The hydraulic retention time (HRT) of 6 d was found optimal for the higher productivity of microalgae in the MBR. Notably, based on biofuel quality, mixotrophically grown microalgal biomass was noted to have better suitability for biomethane production compared to biodiesel. Besides, up to 98.09, 75.74, and 55.86% removal of phosphate, nitrate, and COD, respectively, was recorded within 6 d under mixotrophic growth. Overall, the present findings magnificently demonstrate the efficient recycling of waste glycerol for higher biomass production coupled with phycoremediation using mixotrophic MBR.},
}
@article {pmid35567892,
year = {2022},
author = {Martinez-Malaxetxebarria, I and Girbau, C and Salazar-Sánchez, A and Baztarrika, I and Martínez-Ballesteros, I and Laorden, L and Alonso, R and Fernández-Astorga, A},
title = {Genetic characterization and biofilm formation of potentially pathogenic foodborne Arcobacter isolates.},
journal = {International journal of food microbiology},
volume = {373},
number = {},
pages = {109712},
doi = {10.1016/j.ijfoodmicro.2022.109712},
pmid = {35567892},
issn = {1879-3460},
abstract = {Various species of the genus Arcobacter are regarded as emerging food pathogens and can be cause of human gastroenteric illness, among others. In order to gain knowledge on the risk associated with the presence of arcobacters in retail foods, this study aimed to determine their presence in a variety of products; to evaluate the genetic diversity and the occurrence of virulence and biofilm-associated genes in the isolated strains; and to assess their biofilm activity on polystyrene, borosilicate and stainless steel. Arcobacters were detected in the 22.3% of the analysed samples and the 83 recovered isolates were identified as A. butzleri (n = 53), A. cryaerophilus (n = 24), A. skirrowii (n = 2), A. thereius (n = 3) and A. vitoriensis (n = 1). They were isolated from virtually all tested food types, but mostly from squids and turkey meat (contamination levels of 60% and 40%, respectively). MLST differentiated 68 STs, most of which were novel (89.7%) and represented by a single strain (86.9%). Five novel STs were detected in various isolates derived from seafood, and the statistical analysis revealed their potential association with that type of food product (p < 0,001). All the isolates except one harboured virulence-associated genes and the highest incidence was noted for A. butzleri. Nineteen isolates (23.5%) were able to form biofilms on the different surfaces tested and, of note; glass enhanced the adhesion ability of the majority of them (84.2%). The results highlight the role that common food products can have in the transmission of Arcobacter spp., the pathogenic potential of the different species, and the survival and growth ability of several of them on different food contact surfaces. Therefore, the study provides interesting information regarding the risk arcobacters may pose to human health and the food industry.},
}
@article {pmid35567269,
year = {2022},
author = {Gamal El-Din, MI and Youssef, FS and Altyar, AE and Ashour, ML},
title = {GC/MS Analyses of the Essential Oils Obtained from Different Jatropha Species, Their Discrimination Using Chemometric Analysis and Assessment of Their Antibacterial and Anti-Biofilm Activities.},
journal = {Plants (Basel, Switzerland)},
volume = {11},
number = {9},
pages = {},
pmid = {35567269},
issn = {2223-7747},
support = {RG-25-166-43//The Deanship of Scientific Research (DSR) at King Abdulaziz University (KAU), Jeddah, Saudi Arabia,/ ; },
abstract = {The essential oils of Jatropha intigrimma, J. roseae and J. gossypifolia (Euphorbiaceae) were analyzed employing GC/MS (Gas Chromatography coupled with Mass Spectrometry) analyses. A total of 95 volatile constituents were identified from J. intigrimma, J. gossypifolia and J. roseae essential oils, accounting for 91.61, 90.12, and 86.24%, respectively. Chemometric analysis using principal component analysis (PCA) based on the obtained GC data revealed the formation of three discriminant clusters due to the placement of the three Jatropha species in three different quadrants, highlighting the dissimilarity between them. Heneicosane, phytol, nonacosane, silphiperfol-6-ene, copaborneol, hexatriacontane, octadecamethyl-cyclononasiloxane, 9,12,15-Octadecatrienoic acid, methyl ester and methyl linoleate constitute the key markers for their differentiation. In vitro antibacterial activities of the essential oils were investigated at doses of 10 mg/mL against the Gram-negative anaerobe Escherichia coli using the agar well diffusion method and broth microdilution test. J. gossypifolia essential oil showed the most potent antimicrobial activity, demonstrating the largest inhibition zone (11.90 mm) and the least minimum inhibitory concentration (2.50 mg/mL), followed by the essential oil of J. intigrimma. The essential oils were evaluated for their anti-adhesion properties against the Gram-negative E. coli biofilm using a modified method of biofilm inhibition spectrophotometric assay. J. intigrimma essential oil showed the most potent biofilm inhibitory activity, demonstrating the least minimum biofilm inhibitory concentration (MBIC) of 31.25 µg/mL. In silico molecular docking performed within the active center of E. coli adhesion protein FimH showed that heneicosane, followed by cubebol and methyl linoleate, displayed the best fitting score. Thus, it can be concluded that the essential oils of J. gossypifolia and J. intigrimma leaves represent promising sources for antibacterial drugs with antibiofilm potential.},
}
@article {pmid35565586,
year = {2022},
author = {Xue, M and Fu, D and Hu, J and Shao, Y and Tu, J and Song, X and Qi, K},
title = {The Transcription Regulator YgeK Affects Biofilm Formation and Environmental Stress Resistance in Avian Pathogenic Escherichia coli.},
journal = {Animals : an open access journal from MDPI},
volume = {12},
number = {9},
pages = {},
pmid = {35565586},
issn = {2076-2615},
support = {jit-b-202154//Jinling Institute of Technology Scientific research start-up fund for high-end talents/ ; 31772707//National Natural Science Foundation of China/ ; },
abstract = {Avian pathogenic Escherichia coli (APEC) is one of the most common pathogens in poultry and a potential gene source of human extraintestinal pathogenic E. coli (ExPEC), leading to serious economic losses in the poultry industry and public health concerns. Exploring the pathogenic mechanisms underpinning APEC and the identification of new targets for disease prevention and treatment are warranted. YgeK is a transcriptional regulator in APEC and is localized to the type III secretion system 2 of E. coli. In our previous work, the transcription factor ygeK significantly affected APEC flagella formation, bacterial motility, serum sensitivity, adhesion, and virulence. To further explore ygeK functions, we evaluated its influence on APEC biofilm formation and resistance to environmental stress. Our results showed that ygeK inactivation decreased biofilm formation and reduced bacterial resistance to environmental stresses, including acid and oxidative stress. In addition, the multi-level regulation of ygeK in APEC was analyzed using proteomics, and associations between differentially expressed proteins and the key targets of ygeK were investigated. Overall, we identified ygeK's new function in APEC. These have led us to better understand the transcriptional regulatory ygeK and provide new clues about the pathogenicity of APEC.},
}
@article {pmid35564028,
year = {2022},
author = {Li, Y and Dong, R and Ma, L and Qian, Y and Liu, Z},
title = {Combined Anti-Biofilm Enzymes Strengthen the Eradicate Effect of Vibrio parahaemolyticus Biofilm: Mechanism on cpsA-J Expression and Application on Different Carriers.},
journal = {Foods (Basel, Switzerland)},
volume = {11},
number = {9},
pages = {},
pmid = {35564028},
issn = {2304-8158},
support = {31972141//National Natural Science Foundation of China/ ; 2021YFD2100504//National Key Research and Development Program/ ; },
abstract = {Vibrio parahaemolyticus is a human foodborne pathogen, and it can form a mature biofilm on food and food contact surfaces to enhance their resistance to antibacterial agents. In this study, the effect of anti-biofilm enzymes (combined lipase, cellulase and proteinase K) on the inhibition and eradication of pathogen biofilm was evaluated. The biofilm content of V. parahaemolyticus showed the highest level at the incubation time of 24 h, and the combined enzymes significantly inhibited the biofilm's development. The biofilm's inhibition and eradication rate at an incubation time of 24 h was 89.7% and 66.9%, respectively. The confocal laser scanning microscopic images confirmed that the microcolonies' aggregation and the adhesion of biofilm were inhibited with the combined enzyme treatment. Furthermore, combined enzymes also decreased the concentration of exopolysaccharide (EPS) and disrupted the EPS matrix network, wherein the expression of the EPS-related gene, cpsA-J, was likewise suppressed. The combined enzymes showed an excellent inhibition effect of V. parahaemolyticus biofilm on different carriers, with the highest inhibition rate of 59.35% on nonrust steel plate. This study demonstrates that the combined enzyme of lipase, cellulase and proteinase K could be a novel candidate to overcome biofilm's problem of foodborne pathogens in the food industry.},
}
@article {pmid35563985,
year = {2022},
author = {Yi, Z and Xie, J},
title = {Genomic Analysis of Two Representative Strains of Shewanella putrefaciens Isolated from Bigeye Tuna: Biofilm and Spoilage-Associated Behavior.},
journal = {Foods (Basel, Switzerland)},
volume = {11},
number = {9},
pages = {},
pmid = {35563985},
issn = {2304-8158},
support = {31972142//National Natural Science Foundation of China/ ; 19DZ1207503//key project of Science and Technology Commission of Shanghai Municipality/ ; CARS-47//China Agriculture Research System of MOF and MARA/ ; 19DZ2284000//Shanghai Municipal Science and Technology Project to enhance the capabilities of the platform/ ; },
abstract = {Shewanella putrefaciens can cause the spoilage of seafood and shorten its shelf life. In this study, both strains of S. putrefaciens (YZ08 and YZ-J) isolated from spoiled bigeye tuna were subjected to in-depth phenotypic and genotypic characterization to better understand their roles in seafood spoilage. The complete genome sequences of strains YZ08 and YZ-J were reported. Unique genes of the two S. putrefaciens strains were identified by pan-genomic analysis. In vitro experiments revealed that YZ08 and YZ-J could adapt to various environmental stresses, including cold-shock temperature, pH, NaCl, and nutrient stresses. YZ08 was better at adapting to NaCl stress, and its genome possessed more NaCl stress-related genes compared with the YZ-J strain. YZ-J was a higher biofilm and exopolysaccharide producer than YZ08 at 4 and 30 °C, while YZ08 showed greater motility and enhanced capacity for biogenic amine metabolism, trimethylamine metabolism, and sulfur metabolism compared with YZ-J at both temperatures. That YZ08 produced low biofilm and exopolysaccharide contents and displayed high motility may be associated with the presence of more a greater number of genes encoding chemotaxis-related proteins (cheX) and low expression of the bpfA operon. This study provided novel molecular targets for the development of new antiseptic antisepsis strategies.},
}
@article {pmid35563925,
year = {2022},
author = {Shi, J and Li, SF and Feng, K and Han, SY and Hu, TG and Wu, H},
title = {Improving the Viability of Probiotics under Harsh Conditions by the Formation of Biofilm on Electrospun Nanofiber Mat.},
journal = {Foods (Basel, Switzerland)},
volume = {11},
number = {9},
pages = {},
pmid = {35563925},
issn = {2304-8158},
support = {No. 2020B0301030005//Guangdong Major Project of Basic and Applied Basic Research/ ; No. 2021A1515010765//Natural Science Foundation of Guangdong Province/ ; No. 2020B020226007//Key-Area Research and Development Program of Guangdong Province/ ; No. 2019B110210004//Collaborative Innovation Center for Sports of Guangdong Province/ ; },
abstract = {For improving probiotics' survivability under harsh conditions, this study used Lactiplantibacillus plantarum GIM1.648 as a model microorganism to investigate its ability to produce biofilms on electrospun ethyl cellulose nanofiber mats. SEM observations confirmed that biofilm was successfully formed on the nanofibers, with the latter being an excellent scaffold material. The optimal cultivation conditions for biofilm formation were MRS medium without Tween 80, a culture time of 36 h, a temperature of 30 °C, a pH of 6.5, and an inoculum concentration of 1% (v/v). The sessile cells in the biofilm exhibited improved gastrointestinal and thermal tolerance compared to the planktonic cells. Additionally, the RT-qPCR assay indicated that the luxS gene played a crucial role in biofilm formation, with its relative expression level being 8.7-fold higher compared to the planktonic cells. In conclusion, biofilm formation on electrospun nanofiber mat has great potential for improving the viability of probiotic cells under harsh conditions.},
}
@article {pmid35563384,
year = {2022},
author = {Gómez-Alonso, IS and Martínez-García, S and Betanzos-Cabrera, G and Juárez, E and Sarabia-León, MC and Herrera, MT and Gómez-Chávez, F and Sanchez-Torres, L and Rodríguez-Martínez, S and Cancino-Diaz, ME and Cancino, J and Cancino-Diaz, JC},
title = {Low Concentration of the Neutrophil Proteases Cathepsin G, Cathepsin B, Proteinase-3 and Metalloproteinase-9 Induce Biofilm Formation in Non-Biofilm-Forming Staphylococcus epidermidis Isolates.},
journal = {International journal of molecular sciences},
volume = {23},
number = {9},
pages = {},
pmid = {35563384},
issn = {1422-0067},
support = {20221352SIP//Instituto Politécnico Nacional/ ; 20221193SIP//Instituto Politécnico Nacional/ ; },
mesh = {Animals ; Biofilms ; Cathepsin B ; Cathepsin G ; Metalloproteases ; Mice ; Myeloblastin ; Neutrophils ; Peptide Hydrolases ; *Staphylococcal Infections/microbiology ; *Staphylococcus epidermidis ; },
abstract = {Neutrophils play a crucial role in eliminating bacteria that invade the human body; however, cathepsin G can induce biofilm formation in a non-biofilm-forming Staphylococcus epidermidis 1457 strain, suggesting that neutrophil proteases may be involved in biofilm formation. Cathepsin G, cathepsin B, proteinase-3, and metalloproteinase-9 (MMP-9) from neutrophils were tested on the biofilm induction in commensal (skin isolated) and clinical non-biofilm-forming S. epidermidis isolates. From 81 isolates, 53 (74%) were aap+, icaA-, icaD- genotype, and without the capacity of biofilm formation under conditions of 1% glucose, 4% ethanol or 4% NaCl, but these 53 non-biofilm-forming isolates induced biofilm by the use of different neutrophil proteases. Of these, 62.3% induced biofilm with proteinase-3, 15% with cathepsin G, 10% with cathepsin B and 5% with MMP -9, where most of the protease-induced biofilm isolates were commensal strains (skin). In the biofilm formation kinetics analysis, the addition of phenylmethylsulfonyl fluoride (PMSF; a proteinase-3 inhibitor) showed that proteinase-3 participates in the cell aggregation stage of biofilm formation. A biofilm induced with proteinase-3 and DNAse-treated significantly reduced biofilm formation at an early time (initial adhesion stage of biofilm formation) compared to untreated proteinase-3-induced biofilm (p < 0.05). A catheter inoculated with a commensal (skin) non-biofilm-forming S. epidermidis isolate treated with proteinase-3 and another one without the enzyme were inserted into the back of a mouse. After 7 days of incubation period, the catheters were recovered and the number of grown bacteria was quantified, finding a higher amount of adhered proteinase-3-treated bacteria in the catheter than non-proteinase-3-treated bacteria (p < 0.05). Commensal non-biofilm-forming S. epidermidis in the presence of neutrophil cells significantly induced the biofilm formation when multiplicity of infection (MOI) 1:0.01 (neutrophil:bacteria) was used, but the addition of a cocktail of protease inhibitors impeded biofilm formation. A neutrophil:bacteria assay did not induce neutrophil extracellular traps (NETs). Our results suggest that neutrophils, in the presence of commensal non-biofilm-forming S. epidermidis, do not generate NETs formation. The effect of neutrophils is the production of proteases, and proteinase-3 releases bacterial DNA at the initial adhesion, favoring cell aggregation and subsequently leading to biofilm formation.},
}
@article {pmid35562687,
year = {2022},
author = {Yehia, FAA and Yousef, N and Askoura, M},
title = {Correction: Celastrol mitigates staphyloxanthin biosynthesis and biofilm formation in Staphylococcus aureus via targeting key regulators of virulence; in vitro and in vivo approach.},
journal = {BMC microbiology},
volume = {22},
number = {1},
pages = {130},
pmid = {35562687},
issn = {1471-2180},
}
@article {pmid35561981,
year = {2022},
author = {Li, A and Shi, C and Qian, S and Wang, Z and Zhao, S and Liu, Y and Xue, Z},
title = {Evaluation of antibiotic combination of Litsea cubeba essential oil on Vibrio parahaemolyticus inhibition mechanism and anti-biofilm ability.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {105574},
doi = {10.1016/j.micpath.2022.105574},
pmid = {35561981},
issn = {1096-1208},
abstract = {Vibrio parahaemolyticus (V. parahaemolyticus) is a common pathogen in seafood. The use of antibiotics is a primary tool to prevent and control V. parahaemolyticus in the aquaculture industry. However, V. parahaemolyticus combats the damage caused by antibiotics by forming biofilms under certain conditions. In this study, we analyzed the antibacterial effect and the characteristics of V. parahaemolyticus by experimentally determining the minimum inhibitory concentration (MIC) and the fractional inhibitory concentration index (FICI) values of a combination of the Litsea cubeba essential oil (LCEO) and several commonly used V. parahaemolyticus antibiotics. The bactericidal effect of the essential oil alone and essential oil in combination with the antibiotics were evaluated with time-kill curves. The damage to cell membranes and cell walls were assessed by measuring the content of macromolecules and alkaline phosphatase (AKP) released into the supernatant using V. parahaemolyticus ATCC17802 as the experimental strain. The membrane structure was observed by transmission electron microscopy. The results showed that the MIC value of the LCEO was 1,024 μg/mL, and the LCEO FICI values in combination with tetracycline or oxytetracycline hydrochloride was 0.3125 and 0.75, respectively, indicating synergistic and additive effects. Moreover, LCEO inhibited the growth and promoted the removal of biofilms by reducing the content of hydrophobic and extracellular polysaccharides on the cell surface. This study provides a reference for studying the antibacterial activity of LCEO and the combination of antibiotics to prevent and control the formation of biofilms by V. parahaemolyticus.},
}
@article {pmid35561821,
year = {2022},
author = {Wang, YR and Li, KW and Wang, YX and Liu, XL and Mu, Y},
title = {Nutrient limitation regulates the properties of extracellular electron transfer and hydraulic shear resistance of electroactive biofilm.},
journal = {Environmental research},
volume = {212},
number = {Pt C},
pages = {113408},
doi = {10.1016/j.envres.2022.113408},
pmid = {35561821},
issn = {1096-0953},
abstract = {Understanding the roles of nutrient restriction in extracellular electron transfer (EET) and stability of mixed electroactive biofilm is essential in pollutant degradation and bioenergy production. However, the relevant studies are still limited so far. Herein, the effect of nutrient restriction on the EET pathways and stability of mixed electroactive biofilm was explored. It was found that the electroactive Pseudomonas and Geobacter genera were selectively enriched in the biofilms cultured under total nutrient and P-constrained conditions, and two EET pathways including direct and indirect were found, while Rhodopseudomonas genus was enriched in the N-constrained biofilm, which only had the direct EET pathway. Moreover, multiple analyses including 2D confocal Raman spectra revealed that P-constrained biofilm was rich in extracellular polymeric substances (EPS) especially for polysaccharide, presented a dense and uniform layered distribution, and had better stability than N-constrained biofilm with lower EPS and biofilm with heterostructures cultured under total nutrient conditions.},
}
@article {pmid35561462,
year = {2022},
author = {Zulkifli, M and Abu Hasan, H and Sheikh Abdullah, SR and Muhamad, MH},
title = {A review of ammonia removal using a biofilm-based reactor and its challenges.},
journal = {Journal of environmental management},
volume = {315},
number = {},
pages = {115162},
doi = {10.1016/j.jenvman.2022.115162},
pmid = {35561462},
issn = {1095-8630},
abstract = {Extensive growth of industries leads to uncontrolled ammonia releases to environment. This can result in significant degradation of the aquatic ecology as well as significant health concerns for humans. Knowing the mechanism of ammonia elimination is the simplest approach to comprehending it. Ammonia has been commonly converted to less hazardous substances either in the form of nitrate or nitrogen gas. Ammonia has been converted into nitrite by ammonia-oxidizing bacteria and further reduced to nitrate by nitrite-oxidizing bacteria in aerobic conditions. Denitrification takes place in an anoxic phase and nitrate is converted into nitrogen gas. It is challenging to remove ammonia by employing technologies that do not incur particularly high costs. Thus, this review paper is focused on biofilm reactors that utilize the nitrification process. Many research publications and patents on biofilm wastewater treatment have been published. However, only a tiny percentage of these projects are for full-scale applications, and the majority of the work was completed within the last few decades. The physicochemical approaches such as ammonia adsorption, coagulation-flocculation, and membrane separation, as well as conventional biological treatments including activated sludge, microalgae, and bacteria biofilm, are briefly addressed in this review paper. The effectiveness of biofilm reactors in removing ammonia was compared, and the microbes that effectively remove ammonia were thoroughly discussed. Overall, biofilm reactors can remove up to 99.7% ammonia from streams with a concentration in range of 16-900 mg/L. As many challenges were identified for ammonia removal using biofilm at a commercial scale, this study offers future perspectives on how to address the most pressing biofilm issues. This review may also improve our understanding of biofilm technologies for the removal of ammonia as well as polishing unit in wastewater treatment plants for the water reuse and recycling, supporting the circular economy concept.},
}
@article {pmid35557687,
year = {2022},
author = {Ganesh, PS and Veena, K and Senthil, R and Iswamy, K and Ponmalar, EM and Mariappan, V and Girija, ASS and Vadivelu, J and Nagarajan, S and Challabathula, D and Shankar, EM},
title = {Biofilm-Associated Agr and Sar Quorum Sensing Systems of Staphylococcus aureus Are Inhibited by 3-Hydroxybenzoic Acid Derived from Illicium verum.},
journal = {ACS omega},
volume = {7},
number = {17},
pages = {14653-14665},
pmid = {35557687},
issn = {2470-1343},
abstract = {Biofilm-producing Staphylococcus aureus (S. aureus) is less sensitive to conventional antibiotics than free-living planktonic cells. Here, we evaluated the antibiofilm activity of Illicium verum (I. verum) and one of its constituent compounds 3-hydroxybenzoic acid (3-HBA) against multi-drug-resistant S. aureus. We performed gas chromatography-mass spectroscopy (GC-MS) to identify the major constituents in the methanolic extract of I. verum. Ligand-receptor interactions were studied by molecular docking, and in vitro investigations were performed using crystal violet assay, spreading assay, hemolysis, proteolytic activity, and growth curve analysis. The methanolic extract of I. verum inhibited S. aureus at 4.8 mg/mL, and GC-MS analysis revealed anethole, m-methoxybenzaldehyde, and 3-HBA as the major constituents. Molecular docking attributed the antibiofilm activity to an active ligand present in 3-HBA, which strongly interacted with the active site residues of AgrA and SarA of S. aureus. At a subinhibitory concentration of 2.4 mg/mL, the extract showed biofilm inhibition. Similarly, 3-HBA inhibited biofilm activity at 25 μg/mL (90.34%), 12.5 μg/mL (77.21%), and 6.25 μg/mL (62.69%) concentrations. Marked attrition in bacterial spreading was observed at 2.4 mg/mL (crude extract) and 25 μg/mL (3-HBA) concentrations. The methanol extract of I. verum and 3-HBA markedly inhibited β-hemolytic and proteolytic activities of S. aureus. At the lowest concentration, the I. verum extract (2.4 mg/mL) and 3-HBA (25 μg/mL) did not inhibit bacterial growth. Optical microscopy and SEM analysis confirmed that I. verum and 3-HBA significantly reduced biofilm dispersion without disturbing bacterial growth. Together, we found that the antibiofilm activity of I. verum and 3-HBA strongly targeted the Agr and Sar systems of S. aureus.},
}
@article {pmid35554762,
year = {2022},
author = {Saptami, K and Arokia Balaya Rex, D and Chandrasekaran, J and Rekha, PD},
title = {Competitive interaction of thymol with cviR inhibits quorum sensing and associated biofilm formation in Chromobacterium violaceum.},
journal = {International microbiology : the official journal of the Spanish Society for Microbiology},
volume = {},
number = {},
pages = {},
pmid = {35554762},
issn = {1618-1905},
support = {2019-5152/CMB/BMS//Indian Council of Medical Research/ ; },
abstract = {Biofilm formation associated with quorum sensing (QS) is a community behaviour displayed by many gram-negative pathogenic bacteria that provide survival advantages in hostile conditions. The inhibitors of QS interrupt bacterial communication and coordinated cell signalling for community aggregation in the biofilm. Thymol, a natural monoterpenoid, was tested against QS in Chromobacterium violaceum. As the first step, the interaction of thymol with cviR protein was investigated using in silico approach followed by validation using detailed in vitro experiments. The QS and biofilm studies were performed using the wild type of strain C. violaceum ATCC 12,472 and a mini-Tn5 mutant CV026. The MIC of thymol was established by the broth micro-dilution method, and IC50 value for violacein inhibition was quantified spectrophotometrically by extracting the violacein from the treated cells. Inhibitory effect of thymol on the biofilm was quantified by the crystal violet staining method, and scanning electron microscopy (SEM) was employed for biofilm visualization. The expression of biofilm associated genes (hmsH, hmsR, pilB, and pilT) was evaluated by qRT-PCR analysis. The in silico molecular interactions of thymol with cviR exhibited a G-score of - 5.847 kcal/mol, binding with TYR-80 and SER-155 by Pi-Pi stacking and H-bond, respectively. The MIC of thymol was 160 µg/mL, and the IC50 for violacein inhibition was estimated to be 28 µg/mL. The thymol treatment significantly reduced the biofilm viability and biomass by > 80% along with disruption of the well-organized biofilm architecture. QS inhibitory activity of thymol resulted in the reduction of exopolysaccharide production, swarming motility, and downregulation of biofilm-associated hmsH, hmsR, pilB, and pilT genes. This data establishes the QS inhibitory role of thymol in the biofilm formation in C. violaceum.},
}
@article {pmid35550403,
year = {2022},
author = {Song, Y and Wang, Z and Long, Y and Mao, Y and Jiang, F and Lu, Y},
title = {2-Alkyl-anthraquinones inhibit Candida albicans biofilm via inhibiting the formation of matrix and hyphae.},
journal = {Research in microbiology},
volume = {},
number = {},
pages = {103955},
doi = {10.1016/j.resmic.2022.103955},
pmid = {35550403},
issn = {1769-7123},
abstract = {Candida albicans can form biofilm on biotic and abiotic surfaces of medical implants to cause superficial and systemic infections under specific condition. The formation of hyphae and matrix of C. albicans are considered as probable virulence factors. We assessed the inhibitory activities of 26 anthraquinones against C. albicans biofilm formation, which were substituted by different functional groups including hydroxyl groups, amino groups, carboxyl groups, alkyl groups, and glycoside groups at C1- or C2-position. Among them, anthraquinones without substituents at other positions but only an alkyl group attached to C2-position, namely 2-alkyl-anthraquinones were determined to have significant anti-biofilm activities. Furthermore, 2-ethylanthraquinone can significantly affect genes related to extracellular matrix (PMT6 and IFD6), and hyphal formation (HWP1, ECE1 and EFG1), leading to the disrupted formation of biofilm, by detail transcriptomics analysis. We believed that 2-ethylanthraquinone could inspire more discoveries of anti-biofilm agents against C. albicans.},
}
@article {pmid35549350,
year = {2022},
author = {Giedraitiene, A and Pereckaite, L and Bredelyte-Gruodiene, E and Virgailis, M and Ciapiene, I and Tatarunas, V},
title = {CTX-M-producing Escherichia coli strains: resistance to temocillin, fosfomycin, nitrofurantoin and biofilm formation.},
journal = {Future microbiology},
volume = {},
number = {},
pages = {},
doi = {10.2217/fmb-2021-0202},
pmid = {35549350},
issn = {1746-0921},
abstract = {Aim: ESBL-producing and bacterial biofilms-forming Escherichia coli are associated with antimicrobial treatment failure. This study aimed to investigate the phenotypic resistance mechanisms of CTX-M E. coli against old antibiotics - cell wall synthesis inhibitors temocillin, nitrofurantoin and fosfomycin. Materials &amp; Methods: Susceptibility to old antibiotics testing was performed using disk diffusion method, biofilm formation was evaluated spectrophotometrically, and PCR was used for the determination of CTX-M type. Results &amp; conclusion: Temocillin was active against nearly 93%, nitrofurantoin and fosfomycin, respectively, 91.7% and 98.6% of tested E. coli. Thus, it demonstrated to be a good alternative therapeutic option against ESBL infections. Bacteria resistant to old antibiotics had CTX-M-15 or CTX-M-15, TEM-1 and OXA-1 combinations. No significant association was found between CTX-M E. coli resistance to temocillin, nitrofurantoin and fosfomycin; however, the level of biofilm formation was found as not affected by the type of CTX-M β-lactamases.},
}
@article {pmid35547150,
year = {2022},
author = {Yang, R and Lai, B and Liao, K and Liu, B and Huang, L and Li, S and Gu, J and Lin, Z and Chen, Y and Wang, S and Qiu, Y and Deng, J and Chen, S and Zhuo, C and Zhou, Y},
title = {Overexpression of BIT33_RS14560 Enhances the Biofilm Formation and Virulence of Acinetobacter baumannii.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {867770},
pmid = {35547150},
issn = {1664-302X},
abstract = {Acinetobacter baumannii, a strictly aerobic, non-lactose fermented Gram-negative bacteria, is one of the important pathogens of nosocomial infection. Major facilitator superfamily (MFS) transporter membrane proteins are a class of proteins that widely exists in microbial genomes and have been revealed to be related to biofilm formation in a variety of microorganisms. However, as one of the MFS transporter membrane proteins, little is known about the role of BIT33_RS14560 in A. baumannii. To explore the effects of BIT33_RS14560 on biofilm formation of A. baumannii, the biofilm formation abilities of 62 isolates were firstly investigated and compared with their transcript levels of BIT33_RS14560. Then, this specific gene was over-expressed in a standard A. baumannii strain (ATCC 19606) and two isolates of extensively drug-resistant A. baumannii (XDR-Ab). Bacterial virulence was observed using a Galleria mellonella infection model. High-throughput transcriptome sequencing (RNA seq) was performed on ATCC 19606 over-expressed strain and its corresponding empty plasmid control strain. Spearman's correlation analysis indicated a significant negative correlation (R = -0.569, p = 0.000) between the △CT levels of BIT33_RS1456 and biofilm grading of A. baumannii isolates. The amount of A. baumannii biofilm was relatively high within 12-48 h. Regardless of standard or clinical strains; the biofilm biomass in the BIT33_RS14560 overexpression group was significantly higher than that in the control group (p < 0.0001). Kaplan-Meier survival curve analysis showed that the mortality of G. mellonella was significantly higher when infected with the BIT33_RS14560 overexpression strain (χ2 = 8.462, p = 0.004). RNA-Seq showed that the mRNA expression levels of three genes annotated as OprD family outer membrane porin, glycosyltransferase family 39 protein, and glycosyltransferase family 2 protein, which were related to bacterial adhesion, biofilm formation, and virulence, were significantly upregulated when BIT33_RS14560 was over-expressed. Our findings provided new insights in identifying potential drug targets for the inhibition of biofilm formation. We also developed a practical method to construct an over-expressed vector that can stably replicate in XDR-Ab isolates.},
}
@article {pmid35546969,
year = {2021},
author = {Mohammadi Mollaahmadi, C and Anzabi, Y and Shayegh, J},
title = {Comparison of the Frequency of Biofilm-Forming Genes (icaABCD) in Methicillin-Resistant S. aureus Strains Isolated from Human and Livestock.},
journal = {Archives of Razi Institute},
volume = {76},
number = {6},
pages = {1655-1663},
pmid = {35546969},
issn = {2008-9872},
mesh = {Animals ; Anti-Bacterial Agents/pharmacology ; Biofilms ; Humans ; Livestock ; Methicillin Resistance ; *Methicillin-Resistant Staphylococcus aureus/genetics ; Microbial Sensitivity Tests/veterinary ; Rifampin ; Staphylococcus aureus ; },
abstract = {Methicillin-resistant Staphylococcus aureus (MRSA) can cause infections in both human and animal groups, which is a serious threat to public health worldwide. Attachment and colonization are the first steps for S. aureus pathogenesis, and biofilm-mediated infections have a significant negative impact on human and animal health. The MRSA can adapt to different environments and give rise to different strains of human and animal MRSA, causing transmissions of the disease between humans and animals. This study aimed to investigate biofilm production in vitro, and the presence of icaABCD genes in MRSA isolates in both human as well as the disease transmission between human and animal strains. In total, 39 human and 35 livestock isolates were evaluated by the Congo Red Agar method. The presence of mecA and icaABCDR genes were assessed by polymerase chain reaction (PCR), and finally, the PCR products were examined by agarose gel electrophoresis. The results showed that the mecA gene frequency in human and animal isolates was 64.1% and 36.1%, respectively, and there was a significant relationship between mecA and icaAD in human isolates. In addition, significant relationships were found between icaA and Rifampicin and also between icaC and Chloramphenicol and Penicillin in human isolates. In animal isolates, there was a significant relationship between mecA and Trimethoprim as well as between icaR and Rifampicin. It was concluded that all operon ica genes were involved in biofilm production, but icaA and icaD genes in MRSA were more closely associated with mecA. Both animal and human strains can be involved in disease transmission, but this conclusion should be made cautiously.},
}
@article {pmid35546788,
year = {2022},
author = {Yılmaz Öztürk, B and Yenice Gürsu, B and Dağ, İ},
title = {In vitro effect of farnesol on planktonic cells and dual biofilm formed by Candida albicans and Escherichia coli.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-12},
doi = {10.1080/08927014.2022.2066530},
pmid = {35546788},
issn = {1029-2454},
abstract = {Many biofilm studies have focused on axial biofilms, however biofilms in nature and in vivo environment are multi-species. Farnesol is a sesquiterpene alcohol found in many essential oils. This study investigated the in vitro effects of farnesol on planktonic cells and biofilms of Candida albicans and Escherichia coli. The ultrastructural morphology of farnesol treated cells was evaluated by TEM. According to the XTT results, farnesol caused a significant decrease in metabolic activity and scanning electron microscope images confirmed a reduction in the preformed biofilm as a result of farnesol treatment for single species C. albicans and E. coli biofilms. Although farnesol has less effect on dual species biofilm compared to the single species biofilms, its effect on the dual biofilm was found to be stronger than amphotericin B or ampicillin. Further studies are needed to clarify the role of farnesol on fungal-bacterial biofilms.},
}
@article {pmid35543448,
year = {2022},
author = {Vidal, JM and Ruiz, P and Carrasco, C and Barros, J and Sepúlveda, D and Ruiz-Tagle, N and Romero, A and Urrutia, H and Oliver, C},
title = {Piscirickettsia salmonis forms a biofilm on nylon surface using a CDC Biofilm Reactor.},
journal = {Journal of fish diseases},
volume = {},
number = {},
pages = {},
doi = {10.1111/jfd.13632},
pmid = {35543448},
issn = {1365-2761},
support = {//Agencia Nacional de Investigación y Desarrollo (ANID)/ ; 11180994//The Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)/ ; 15110027//Fondo de Financiamiento de Centros de Investigación (FONDAP) Interdisciplinary Center for Aquaculture Research (INCAR)/ ; //Vicerrectoría de Investigación, Desarrollo y Creación Artística of the Universidad Austral de Chile (VIDCA-UACh)/ ; },
abstract = {Research into Piscirickettsia salmonis biofilms on materials commonly used in salmon farming is crucial for understanding its persistence and virulence. We used the CDC Biofilm Reactor to investigate P. salmonis (LF-89 and EM-90) biofilm formation on Nylon, Stainless steel (316L), Polycarbonate and High-Density Polyethylene (HDPE) surfaces. After 144 h of biofilm visualization by scanning confocal laser microscopy under batch growth conditions, Nylon coupons generated the greatest biofilm formation and coverage compared to Stainless steel (316L), Polycarbonate and HDPE. Additionally, P. salmonis biofilm formation on Nylon was significantly greater (p ≤ .01) than Stainless steel (316L), Polycarbonate and HDPE at 288 h. We used Nylon coupons to determine the kinetic parameters of the planktonic and biofilm phases of P. salmonis. The two strains had similar latencies in the planktonic phase; however, LF-89 maximum growth was 2.5 orders of magnitude higher (Log cell ml-1). Additionally, LF-89 had a specified growth rate (µmax) of 0.0177 ± 0.006 h-1 and a generation time of 39.2 h. This study contributes to a deeper understanding of the biofilm formation by P. salmonis and elucidates the impact of the biofilm on aquaculture systems.},
}
@article {pmid35538403,
year = {2022},
author = {Pourhajibagher, M and Alaeddini, M and Etemad-Moghadam, S and Rahimi Esboei, B and Bahrami, R and Miri Mousavi, RS and Bahador, A},
title = {Quorum quenching of Streptococcus mutans via the nano-quercetin-based antimicrobial photodynamic therapy as a potential target for cariogenic biofilm.},
journal = {BMC microbiology},
volume = {22},
number = {1},
pages = {125},
pmid = {35538403},
issn = {1471-2180},
mesh = {Anti-Bacterial Agents/pharmacology ; *Anti-Infective Agents/pharmacology ; Biofilms ; *Photochemotherapy/methods ; Quercetin/pharmacology ; Quorum Sensing ; Reactive Oxygen Species/pharmacology ; Streptococcus mutans ; },
abstract = {BACKGROUND: Quorum sensing (QS) system can regulate the expression of virulence factors and biofilm formation in Streptococcus mutans. Antimicrobial photodynamic therapy (aPDT) inhibits quorum quenching (QQ), and can be used to prevent microbial biofilm. We thereby aimed to evaluate the anti-biofilm potency and anti-metabolic activity of nano-quercetin (N-QCT)-mediated aPDT against S. mutans. Also, in silico evaluation of the inhibitory effect of N-QCT on the competence-stimulating peptide (CSP) of S. mutans was performed to elucidate the impact of aPDT on various QS-regulated genes.<br><br>METHODS: Cytotoxicity and intracellular reactive oxygen species (ROS) generation were assessed following synthesis and confirmation of N-QCT. Subsequently, the minimum biofilm inhibitory concentration (MBIC) of N-QCT against S. mutans and anti-biofilm effects of aPDT were assessed using colorimetric assay and plate counting. Molecular modeling and docking analysis were performed to confirm the connection of QCT to CSP. The metabolic activity of S. mutans and the expression level of various genes involved in QS were evaluated by flow cytometry and reverse transcription quantitative real-time PCR, respectively.<br><br>RESULTS: Successful synthesis of non-toxic N-QCT was confirmed through several characterization tests. The MBIC value of N-QCT against S. mutans was 128 μg/mL. Similar to the crystal violet staining, the results log10 CFU/mL showed a significant degradation of preformed biofilms in the group treated with aPDT compared to the control group (P < 0.05). Following aPDT, metabolic activity of S. mutans also decreased by 85.7% (1/2 × MBIC of N-QCT) and 77.3% (1/4 × MBIC of N-QCT), as compared to the control values (P < 0.05). In silico analysis showed that the QCT molecule was located in the site formed by polypeptide helices of CSP. The relative expression levels of the virulence genes were significantly decreased in the presence of N-QCT-mediated aPDT (P < 0.05).<br><br>CONCLUSIONS: The combination of N-QCT with blue laser as a QQ-strategy leads to maximum ROS generation, disrupts the microbial biofilm of S. mutans, reduces metabolic activity, and downregulates the expression of genes involved in the QS pathway by targeting genes of the QS signaling system of S. mutans.},
}
@article {pmid35537700,
year = {2022},
author = {He, Y and Pang, J and Yang, Z and Zheng, M and Yu, Y and Liu, Z and Zhao, B and Hu, G and Yin, R},
title = {Toluidine blue O-induced photoinactivation inhibit the biofilm formation of methicillin-resistant Staphylococcus aureus.},
journal = {Photodiagnosis and photodynamic therapy},
volume = {},
number = {},
pages = {102902},
doi = {10.1016/j.pdpdt.2022.102902},
pmid = {35537700},
issn = {1873-1597},
abstract = {BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is increasingly resistant to conventional antimicrobial therapies, representing high morbidity and mortality. Photodynamic antimicrobial chemotherapy (PACT) is one method that combines visible harmless light with the optimum wavelength with photosensitizers or dyes, producing singlet oxygen (1O2) and reactive oxygen strains (ROS), making permanent damages to the target cells. The purpose of this research is to evaluate the suppression efficacy of toluidine blue O (TBO)-mediated PACT on mature MRSA biofilm in vitro.<br><br>METHODS: In this study, the 48 hours mature biofilm of the multidrug-resistant Staphylococcus aureus strain MRSA252 was used. The photodynamic therapy (PDT) group was treated with different concentrations of TBO (0.5, 0.75,1.0 or 1.25 µM) and different doses of red light (635 ± 5 nm wavelength; 30 or 50 J/cm2). The biofilms viability after PDT were evaluated by crystal violet (CV) staining assay and {2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetra-zolium hydroxide}
(XTT) assay; meanwhile, the morphological changes were detected by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM), separately. Moreover, the biofilms virulence was evaluated by red blood cell (RBC) hemolysis assay and staphylococcal virulence factor enterotoxins A (SEA) detected by enzyme linked immunosorbent assay (ELISA). After PDT, the biofilm was re-cultured for extra 48 h. Its formation viability and virulence were detected again. All data were analyzed by ANOVAs followed by the Games Howell post hoc test (α = 0.05).<br><br>RESULTS: The biofilm was inactivated about 2.3 log10 at 1.25 µM with 30 J/cm2 illumination, and 3.5 log10 with 50 J/cm2 after PDT (P<0.05). XTT assays demonstrated the viability of mature MRSA biofilms was reduced after PACT. PDT group shows a distinct reduction in RBC hemolysis rate and the concentration of SEA compared to the control groups. The morphological features of the biofilms showed great changes, such as shrinkage, fissure, fragmentation, and rarefaction after being treated by TBO-PDT and observed by SEM. The recovery of the structure and virulence of biofilm were suppressed after PDT.<br><br>CONCLUSION: TBO-mediated PDT could destroy the biofilm structure, reduce its virulence and depress its self-recovery.},
}
@article {pmid35537631,
year = {2022},
author = {Jiang, M and Zhang, Y and Zheng, J and Li, H and Ma, J and Zhang, X and Wei, Q and Wang, X and Zhang, X and Wang, Z},
title = {Mechanistic insights into CO2 pressure regulating microbial competition in a hydrogen-based membrane biofilm reactor for denitrification.},
journal = {Chemosphere},
volume = {},
number = {},
pages = {134875},
doi = {10.1016/j.chemosphere.2022.134875},
pmid = {35537631},
issn = {1879-1298},
abstract = {CO2 is a proven pH regulator in hydrogen-based membrane biofilm reactor (H2-MBfR) but how its pressure regulates microbial competition in this system remains unclear. This work evaluates the CO2 pressure dependent system performance, CO2 allocation, microbial structure and activity of CO2 source H2-MBfR. The optimum system performance was reached at the CO2 pressure of 0.008 MPa, and this pressure enabled 0.18 g C/(m2·d) of dissolved inorganic carbon (DIC) allocated to denitrifying bacteria (DNB) for carbon source anabolism and denitrification-related proton compensation, while inducing a bulk liquid pH (pH 7.4) in favor of DNB activity by remaining 0.21 g C/(m2·d) of DIC as pH buffer. Increasing CO2 pressure from 0.008 to 0.016 MPa caused the markedly changed DNB composition, and the diminished DNB population was accompanied by the enrichment of sulfate-reducing bacteria (SRB). A high CO2 pressure of 0.016 MPa was estimated to induce the enhanced SRB activity and weakened DNB activity.},
}
@article {pmid35536751,
year = {2022},
author = {Yang, M and Özdemir, Z and Kim, H and Nah, S and Andris, E and Li, X and Wimmer, Z and Yoon, J},
title = {Acid-Responsive Nanoporphyrin Evolution for Near-Infrared Fluorescence-Guided Photo-Ablation of Biofilm.},
journal = {Advanced healthcare materials},
volume = {},
number = {},
pages = {e2200529},
doi = {10.1002/adhm.202200529},
pmid = {35536751},
issn = {2192-2659},
support = {22078066//National Natural Science Foundation of China/ ; FV10599//MPO/ ; FV30300//MPO/ ; //National Research Foundation of Korea (NRF)/ ; 2021R1A6A1A10039823//Ministry of Education/ ; 2022R1A2C3005420//Ministry of Education/ ; //China Scholarship Council/ ; VAJVA-19-48//Czech Academy of Sciences/ ; //University of Chemistry and Technology Prague/ ; 2019/2020//MOBI traineeship Programme/ ; CZ.02.1.01/0.0/0.0/16_019/0000729//European Regional Development/ ; //Ministry of Education, Youth and Sports of the Czech Republic/ ; 90140//e-INFRA CZ/ ; },
abstract = {Combating biofilm infections remains a challenge due to the shield and acidic conditions. Herein, an acid-responsive nanoporphyrin (PN3-NP) based on the self-assembly of a water-soluble porphyrin derivative (PN3) is constructed. Additional kinetic control sites formed by the conjugation of the spermine molecules to a porphyrin macrocycle make PN3 self-assemble into stable nanoparticles (PN3-NP) in the physiological environment. Noteworthily, near-infrared (NIR) fluorescence monitoring and synergistic photodynamic therapy (PDT) and photothermal therapy (PTT) effects of PN3-NP can be triggered by the acidity in biofilms, accompanied by intelligent transformation into dot-like nanospheres. Thus, damage to normal tissue is effectively avoided and accurate diagnosis and treatment of biofilms is achieved successfully. The good results of fluorescence imaging-guided photo-ablation of antibiotic-resistant strains methicillin-resistant Staphylococcus aureus (MRSA) biofilms verify that PN3-NP is a promising alternative to antibiotics. Meanwhile, this strategy also opens new horizons to engineer smart nano-photosensitizer for accurate diagnosis and treatment of biofilms.},
}
@article {pmid35535650,
year = {2022},
author = {Savorana, G and Słomka, J and Stocker, R and Rusconi, R and Secchi, E},
title = {A microfluidic platform for characterizing the structure and rheology of biofilm streamers.},
journal = {Soft matter},
volume = {},
number = {},
pages = {},
doi = {10.1039/d2sm00258b},
pmid = {35535650},
issn = {1744-6848},
abstract = {Biofilm formation is the most successful survival strategy for bacterial communities. In the biofilm lifestyle, bacteria embed themselves in a self-secreted matrix of extracellular polymeric substances (EPS), which acts as a shield against mechanical and chemical insults. When ambient flow is present, this viscoelastic scaffold can take a streamlined shape, forming biofilm filaments suspended in flow, called streamers. Streamers significantly disrupt the fluid flow by causing rapid clogging and affect transport in aquatic environments. Despite their relevance, the structural and rheological characterization of biofilm streamers is still at an early stage. In this work, we present a microfluidic platform that allows the reproducible growth of biofilm streamers in controlled physico-chemical conditions and the characterization of their biochemical composition, morphology, and rheology in situ. We employed isolated micropillars as nucleation sites for the growth of single biofilm streamers under the continuous flow of a diluted bacterial suspension. By combining fluorescent staining of the EPS components and epifluorescence microscopy, we were able to characterize the biochemical composition and morphology of the streamers. Additionally, we optimized a protocol to perform hydrodynamic stress tests in situ, by inducing controlled variations of the fluid shear stress exerted on the streamers by the flow. Thus, the reproducibility of the formation process and the testing protocol make it possible to perform several consistent experimental replicates that provide statistically significant information. By allowing the systematic investigation of the role of biochemical composition on the structure and rheology of streamers, this platform will advance our understanding of biofilm formation.},
}
@article {pmid35534609,
year = {2022},
author = {Momenijavid, M and Salimizand, H and Korani, A and Dianat, O and Nouri, B and Ramazanzadeh, R and Ahmadi, A and Rostamipour, J and Khosravi, MR},
title = {Effect of calcium hydroxide on morphology and physicochemical properties of Enterococcus faecalis biofilm.},
journal = {Scientific reports},
volume = {12},
number = {1},
pages = {7595},
pmid = {35534609},
issn = {2045-2322},
support = {IR.MUK.REC.1396/301//Kurdistan University Of Medical Sciences/ ; },
mesh = {Anti-Bacterial Agents/pharmacology ; Biofilms ; *Calcium Hydroxide/pharmacology ; *Enterococcus faecalis ; Root Canal Irrigants/pharmacology ; Root Canal Therapy ; },
abstract = {Calcium hydroxide Ca(OH)2 has been used as an intracanal medicament to targets microbial biofilms and avert secondary infection in the root canal system. This study evaluated the effects of this material on the morphology and physicochemical properties of an established in-vitro biofilm of Enterococcus faecalis. A biofilm of E. faecalis was grown in multichannel plates. The chemicals including Ca2+, OH-, and saturated Ca(OH)2 (ie 21.6 mM) were prepared in order to evaluate which component eradicated or amplified biofilm structure. Various biochemical and microscopic methods were used to investigate the properties of the biofilm. Biofilms treated with Ca(OH)2 absorbed more Ca2+ because of the alkaline pH of the environment and the ions affected the physicochemical properties of the E. faecalis biofilm. A denser biofilm with more cavities and a granular surface was observed in the presence of Ca2+ ions. This resulted in a decrease in the surface-to-biofilm ratio with increases in its biomass, thickness, colony size, and volume. Calcium hydroxide did not destroy E. faecalis biofilms but rather contributed to the biofilm structure. This in-vitro study sheds light on a missing link in the formation of E. faecalis biofilm in which the Ca2+ in Ca(OH)2.},
}
@article {pmid35532279,
year = {2022},
author = {Doucet, AN and Slipski, CJ and Golding, GR and Mulvey, MR and Bay, DC},
title = {Generation of Greater Bacterial Biofilm Biomass using PCR-Plate Deep Well Microplate Devices.},
journal = {Journal of visualized experiments : JoVE},
volume = {},
number = {182},
pages = {},
doi = {10.3791/63069},
pmid = {35532279},
issn = {1940-087X},
mesh = {Anti-Bacterial Agents ; Bacteria ; Biofilms ; Biomass ; *Escherichia coli ; Microbial Sensitivity Tests ; Polymerase Chain Reaction ; Polypropylenes ; *Polystyrenes ; Pseudomonas aeruginosa ; },
abstract = {Bacterial biofilms are difficult to eradicate from surfaces using conventional antimicrobial interventions. High-throughput 96-well microplate methods are frequently used to cultivate bacterial biofilms for rapid antimicrobial susceptibility testing to calculate minimal biofilm eradication concentration (MBEC) values. Standard biofilm devices consist of polystyrene pegged-lids fitted to 96-well microplates and are ideal for measuring biofilm biomass and MBEC values, but these devices are limited by available peg surface area for biomass accumulation and cost. Here, we outline a protocol to use self-assembled polypropylene 96-well deep well PCR-plate pegged-lid device to grow Escherichia coli BW25113 and Pseudomonas aeruginosa PAO1 biofilms. A comparison of 24-hour biofilms formed on standard and deep well devices by each species using crystal violet biomass staining and MBEC determination assays are described. The larger surface area of deep well devices expectedly increased overall biofilm formation by both species 2-4-fold. P. aeruginosa formed significantly greater biomass/mm2 on deep well pegs as compared to the standard device. E. coli had greater biomass/mm2 on standard polystyrene devices as compared the deep well device. Biofilm eradication assays with disinfectants such as sodium hypochlorite (bleach) or benzalkonium chloride (BZK) showed that both compounds could eliminate E. coli and P. aeruginosa biofilms from both devices but at different MBEC values. BZK biofilm eradication resulted in variable E. coli MBEC values between devices, however, bleach demonstrated reproducible MBEC values for both species and devices. This study provides a high throughput deep well method for growing larger quantities of biofilms on polypropylene devices for downstream studies requiring higher amounts of static biofilm.},
}
@article {pmid35532264,
year = {2022},
author = {Buckingham-Meyer, K and Miller, LA and Parker, AE and Walker, DK and Sturman, P and Novak, I and Goeres, DM},
title = {Harvesting and Disaggregation: An Overlooked Step in Biofilm Methods Research.},
journal = {Journal of visualized experiments : JoVE},
volume = {},
number = {182},
pages = {},
doi = {10.3791/62390},
pmid = {35532264},
issn = {1940-087X},
mesh = {*Biofilms ; *Sonication ; },
abstract = {Biofilm methods consist of four distinct steps: growing the biofilm in a relevant model, treating the mature biofilm, harvesting the biofilm from the surface and disaggregating the clumps, and analyzing the sample. Of the four steps, harvesting and disaggregation are the least studied but nonetheless critical when considering the potential for test bias. This article demonstrates commonly used harvesting and disaggregation techniques for biofilm grown on three different surfaces. The three biofilm harvesting and disaggregation techniques, gleaned from an extensive literature review, include vortexing and sonication, scraping and homogenization, and scraping, vortexing and sonication. Two surface types are considered: hard non-porous (polycarbonate and borosilicate glass) and porous (silicone). Additionally, we provide recommendations for the minimum information that should be included when reporting the harvesting technique followed and an accompanying method to check for bias.},
}
@article {pmid35531251,
year = {2022},
author = {Mekky, AF and Hassanein, WA and Reda, FM and Elsayed, HM},
title = {Anti-biofilm potential of Lactobacillus plantarum Y3 culture and its cell-free supernatant against multidrug-resistant uropathogen Escherichia coli U12.},
journal = {Saudi journal of biological sciences},
volume = {29},
number = {4},
pages = {2989-2997},
pmid = {35531251},
issn = {1319-562X},
abstract = {Uropathogens develop biofilms on urinary catheters, resulting in persistent and chronic infections that are associated with resistance to antimicrobial therapy. Therefore, the current study was performed to control biofilm-associated urinary tract infections through assaying the anti-biofilm ability of lactic acid bacteria (LAB) against multidrug-resistant (MDR) uropathogens. Twenty LAB were obtained from pickles and fermented dairy products, and screened for their anti-biofilm and antimicrobial effects against MDR Escherichia coli U12 (ECU12). Lactobacillus plantarum Y3 (LPY3) (MT498405), showed the highest inhibitory effect and biofilm production. Pre-coating of a microtitre plate with LPY3 culture was more potent than co-incubation. Pre-coating with LPY3 culture generated a higher anti-biofilm effect with an adherence of 14.5% than cell free supernatant (CFS) (31.2%). Anti-biofilm effect of CFS was heat stable up to 100 °C with higher effect at pH 4-6. Pre-coating urinary catheter with LPY3 culture reduced the CFU/cm2 of ECU12 attached to the catheter for up to seven days. Meanwhile, CFS reduced the ECU12 CFU/cm2 for up to four days. Scanning electron microscope confirmed the reduction of ECU12 adherence to catheters after treatment with CFS. Therefore, Lactobacillus plantarum can be applied in medical devices as prophylactic agent and as a natural biointervention to treat urinary tract infections.},
}
@article {pmid35527134,
year = {2021},
author = {Joshi, KM and Shelar, A and Kasabe, U and Nikam, LK and Pawar, RA and Sangshetti, J and Kale, BB and Singh, AV and Patil, R and Chaskar, MG},
title = {Biofilm inhibition in Candida albicans with biogenic hierarchical zinc-oxide nanoparticles.},
journal = {Materials science &amp; engineering. C, Materials for biological applications},
volume = {},
number = {},
pages = {112592},
doi = {10.1016/j.msec.2021.112592},
pmid = {35527134},
issn = {1873-0191},
abstract = {The present study demonstrates lignin (L), fragments of lignin (FL), and oxidized fragmented lignin (OFL) as templates for the synthesis of zinc oxide nanoparticles (ZnO NPs) viz., lignin-ZnO (L-ZnO), hierarchical FL-ZnO, and OFL-ZnO NPs. The X-ray diffraction patterns confirmed the formation of phase pure ZnO NPs with a hexagonal wurtzite structure. Electron microscopy confirmed the hierarchical structures with one-dimensional arrays of ZnO NPs with an average particle diameter of 40 nm. The as-synthesized L-ZnO, FL-ZnO, and OFL-ZnO NPs were tested in-vitro for growth and virulence inhibition (morphogenesis and biofilm) in Candida albicans. L-ZnO, FL-ZnO, and OFL-ZnO NPs all inhibited growth and virulence. Growth and virulence inhibitions were highest (more than 90%, respectively at 125, 31.2, and 62.5 μg/mL) in presence of FL-ZnO NPs, indicating that the hierarchical FL-ZnO NPs were potent growth and virulence inhibiting agent than non-hierarchical ZnO NPs. Furthermore, the real-time polymerase chain (RT-PCR) was used to study the virulence inhibition molecular mechanisms of L-ZnO, FL-ZnO, and OFL-ZnO NPs. RT-PCR results showed that the downregulation of phr1, phr2, efg1, hwp1, ras1, als3 and als4, and the upregulation of bcy1, nrg1, and tup1 genes inhibited the virulence in C. albicans. Lastly, we also performed in-vitro test cell cytotoxicity on the cell line, mouse embryo 3T3L1, and in-vivo toxicity on Rats, which showed that FL-ZnO NPs were biocompatible and nontoxic.},
}
@article {pmid35526753,
year = {2022},
author = {Choi, JH and Jung, EH and Leea, ES and Jung, HI and Kim, BI},
title = {Anti-biofilm activity of chlorhexidine-releasing elastomerics against dental microcosm biofilms.},
journal = {Journal of dentistry},
volume = {},
number = {},
pages = {104153},
doi = {10.1016/j.jdent.2022.104153},
pmid = {35526753},
issn = {1879-176X},
abstract = {OBJECTIVE: To evaluate the anti-biofilm activity of chlorhexidine-releasing elastomerics (CRE) developed to prevent biofilm-related diseases in orthodontic patients, using dental microcosm biofilms.<br><br>METHODS: Elastomerics coated with one of two solutions (CRE 1 and 2) were attached to bovine enamel specimens. Uncoated elastomerics were used for negative (distilled water [DW]) and positive (0.1% chlorhexidine [CHX]) control groups. After saliva inoculation on the surface of the specimen for biofilm formation, DW and CRE groups were treated with DW, and the positive control group was treated with CHX twice a day for 5 min. After 7 days of biofilm formation, colony-forming units (CFUs, total and aciduric bacteria), red/green (R/G) ratio, biofilm thickness, live/dead cell ratio, and bacterial morphology in the biofilms were evaluated. Enamel demineralization was evaluated by fluorescence loss (ΔF).<br><br>RESULTS: The CFUs of total and aciduric bacteria and R/G ratios in the CRE groups were significantly lower than those in the DW group with a reduction by 13%, 13%, and 19%, respectively (p < 0.05). The CFUs of total bacteria was significantly lower in the CRE groups than in the CHX group (p < 0.05). Among the CRE groups, only CRE 1 exhibited a significantly reduced biofilm thickness of 54% compared to the DW group (p < 0.05) and apparent changes in bacterial morphology. ΔF in the CRE groups was significantly higher by 36% compared to that in the DW group (p < 0.05).<br><br>CONCLUSIONS: CREs exhibited anti-biofilm and demineralization-inhibiting efficacy. Particularly, CRE 1 using dichloromethane as the solvent was most effective against biofilms.<br><br>CLINICAL SIGNIFICANCE: Chlorhexidine-releasing elastomerics exhibited increased anti-biofilm and demineralization-inhibiting efficacy compared to 0.1% chlorhexidine mouthwash. Therefore, it is possible to prevent biofilm-related diseases simply and effectively by applying chlorhexidine-releasing elastomerics to orthodontic patients.},
}
@article {pmid35526677,
year = {2022},
author = {Ball, AL and Augenstein, ED and Wienclaw, TM and Richmond, BC and Freestone, CA and Lewis, JM and Thompson, JS and Pickett, BE and Berges, BK},
title = {Characterization of Staphylococcus aureus biofilms via crystal violet binding and biochemical composition assays of isolates from hospitals, raw meat, and biofilm-associated gene mutants.},
journal = {Microbial pathogenesis},
volume = {167},
number = {},
pages = {105554},
doi = {10.1016/j.micpath.2022.105554},
pmid = {35526677},
issn = {1096-1208},
abstract = {Staphylococcus aureus (SA) is a gram-positive coccus and an opportunistic pathogen of humans. The ability of SA to form biofilms is an important virulence mechanism because biofilms are protected from host immune responses and antibiotic treatment. This study examines the relative biofilm strength of a variety of hospital and meat-associated strains of SA, using a crystal violet (CV) staining assay. Biofilms were treated with either DNase or proteinase K prior to CV staining, and compared to mock-treated results, to better understand the biochemical composition. Biofilm polysaccharide concentration was also measured using the phenol sulfuric-acid assay which was normalized to base biofilm strength. We found that hospital-associated isolates have biofilms that bind significantly more CV than for meat isolates and are significantly more protein and polysaccharide-based while meat isolates have significantly more DNA-based biofilms. This study also investigates the effects that biofilm-related genes have on biofilm formation and composition by analyzing specific transposon mutants of genes previously shown to play a role in biofilm development. agrA, atl, clfA, fnbA, purH, and sarA mutants produce significantly weaker biofilms (bind less CV) as compared to a wild-type control, whereas the acnA mutant produces a significantly stronger biofilm. Biofilms formed from these mutant strains were treated (or mock-treated) with DNase or proteinase K and tested with phenol and sulfuric acid to determine what role these genes play in biofilm composition. The acnA, clfA, fnbA, and purH mutants showed significant reduction in biofilm staining after either proteinase K or DNase treatment, agrA and sarA mutants showed significant biofilm reduction after only proteinase K treatment, and an atl mutant did not show significant biofilm reduction after either proteinase K or DNase treatment. These data suggest that biofilms that form without acnA, clfA, fnbA, and purH are DNA- and protein-based, that biofilms lacking agrA and sarA are mainly protein-based, and biofilms lacking atl are mainly polysaccharide-based. These results help to elucidate how these genes affect biofilm formation and demonstrate how mutating biofilm-related genes in SA can cause a change in biofilm composition.},
}
@article {pmid35526143,
year = {2022},
author = {Sorensen, HH and Magnussen, RA and DiBartola, AC and Mallory, NT and Litsky, AS and Stoodley, P and Swinehart, SD and Duerr, RA and Kaeding, CC and Flanigan, DC},
title = {Influence of Staphylococcus epidermidis Biofilm on the Mechanical Strength of Soft Tissue Allograft.},
journal = {Journal of orthopaedic research : official publication of the Orthopaedic Research Society},
volume = {},
number = {},
pages = {},
doi = {10.1002/jor.25360},
pmid = {35526143},
issn = {1554-527X},
support = {R01 GM124436/GM/NIGMS NIH HHS/United States ; },
abstract = {We sought to determine the impact of bacterial inoculation and length of exposure on the mechanical integrity of soft tissue tendon grafts. Cultures of S. epidermidis were inoculated on human tibialis posterior (TP) cadaveric tendon to grow biofilms. A low inoculum in 10% growth medium was incubated for 30 minutes to replicate conditions of clinical infection. Growth conditions assessed included inoculum concentrations of 100, 1000, 10000 CFU. Tests using the MTS Bionix system were performed to assess the influence of bacterial biofilms on tendon strength. Load-to-failure testing was performed on the tendons, and the ultimate tensile strength was obtained from the maximal force and the cross-sectional area. Displacements of tendon origin to maximal displacement were normalized to tendon length to obtain strain values. Tendon force-displacement and stress-strain relationships were calculated, and Young's modulus was determined. Elastic modulus and ultimate tensile strength decreased with increasing bioburden. Young's modulus was greater in uninoculated controls compared to tendons inoculated at 10,000 CFU (p=0.0011) but unaffected by bacterial concentrations of 100 and 1,000 CFU (p=0.054, p=0.078). Increasing bioburden was associated with decreased peak load to failure (p=0.043) but was most significant compared to the control under the 10,000 CFU and 1,000 CFU growth conditions (p=0.0005, p=0.049). Presence of S. epidermidis increased elasticity and decreased ultimate tensile stress of human cadaveric tendons, with increasing effect noted with increasing bioburden. This article is protected by copyright. All rights reserved.},
}
@article {pmid35525944,
year = {2022},
author = {Bakht, M and Alizadeh, SA and Rahimi, S and Kazemzadeh Anari, R and Rostamani, M and Javadi, A and Peymani, A and Marashi, SMA and Nikkhahi, F},
title = {Phenotype and genetic determination of resistance to common disinfectants among biofilm-producing and non-producing Pseudomonas aeruginosa strains from clinical specimens in Iran.},
journal = {BMC microbiology},
volume = {22},
number = {1},
pages = {124},
pmid = {35525944},
issn = {1471-2180},
mesh = {Anti-Bacterial Agents/pharmacology ; Biofilms ; *Disinfectants/pharmacology ; Edetic Acid/pharmacology ; Humans ; Iran ; Microbial Sensitivity Tests ; Phenotype ; *Pseudomonas aeruginosa ; Sodium Hypochlorite/pharmacology ; },
abstract = {BACKGROUND: Pseudomonas aeruginosa is a common pathogen in Hospitalized patients, and its various resistance mechanisms contribute to patient morbidity and mortality. The main aims of the present study were to assess the susceptibility of biofilm-producing and non-producing P. aeruginosa isolates to the five commonly used Hospital disinfectants, to evaluate the synergistic effect of selected disinfectants and Ethylene-diamine-tetra acetic acid (EDTA), and the effect of exposure to sub-inhibitory concentrations of Sodium hypochlorite on antimicrobial susceptibility test.<br><br>RESULTS: The results showed that sodium hypochlorite 5% and Ethanol 70% were the most and least effective disinfectants against P. aeruginosa, respectively. The addition of EDTA significantly increased the effectiveness of the selected disinfectants. The changes in the antibiotic-resistance profiles after exposure to sub-inhibitory concentrations of disinfectants were observed for different classes of antibiotics (Carbapenems, Aminoglycosides, Cephalosporins, Fluoroquinolones). As well as near the all isolates harbored efflux pump genes and 117 (97.5%) of isolates produced biofilm.<br><br>CONCLUSION: In the current study, the mixture of disinfectant and EDTA were the most suitable selection to disinfect Hospital surfaces and instruments. Also, it was clear that exposure to sub-inhibitory concentrations of Sodium hypochlorite results in resistance to some antibiotics in P. aeruginosa species. Strong and intermediate biofilm formers belonged to MDR/XDR strains. Future studies should include more complex microbial communities residing in the Hospitals, and more disinfectants use in Hospitals.},
}
@article {pmid35525433,
year = {2022},
author = {Yu, Y and Zhao, Y and He, Y and Pang, J and Yang, Z and Zheng, M and Yin, R},
title = {Inhibition of efflux pump encoding genes and biofilm formation by sub-lethal photodynamic therapy in methicillin susceptible and resistant Staphylococcus aureus.},
journal = {Photodiagnosis and photodynamic therapy},
volume = {},
number = {},
pages = {102900},
doi = {10.1016/j.pdpdt.2022.102900},
pmid = {35525433},
issn = {1873-1597},
abstract = {BACKGROUND: Photodynamic therapy (PDT) is an effective method to inactivate microorganisms based on reactive oxygen species (ROS) generated by photosensitizer and light at certain wavelength. Exposure to sub-lethal dose of PDT (sPDT) could activate the regulatory systems in the surviving bacteria in response to oxidative stress. This study aimed to evaluate the effect of sPDT on efflux pump and biofilm formation in Staphylococcus aureus (S. aureus), which are two important virulence related factors.<br><br>METHODS: Different light irradiation time and toluidine blue O (TBO) concentrations were tested to select a sPDT in methicillin-susceptible and methicillin-resistant S. aureus (MSSA and MRSA). Efflux function was evaluated with EtBr efflux experiment. Biofilm formation was evaluated by crystal violet staining. Gene expressions of norA, norB, sepA, mepA and mdeA following sPDT were analyzed with real-time PCR.<br><br>RESULTS: Sub-lethal PDT was set at 40 J/cm2 associated with 0.5 μM TBO. Efflux function was significantly inhibited in both strains. The average expression levels of mdeA and mepA in MSSA and MRSA were increased by (3.09, 1.77, 1.57) and (3,44, 1.59, 6.29) fold change respectively, norB and sepA were decreased by (3.77, 6.14) and (3.02, 3.47) fold change respectively. Expression level of norA was decreased by 5.44-fold change in MSSA but increased by 2.80-fold change in MRSA. Biofilm formation in both strains was impeded.<br><br>CONCLUSIONS: TBO-mediated sPDT could inhibit efflux pump function, alter efflux pump encoding gene expression levels and retard biofilm formation in MSSA and MRSA. Therefore, sPDT is proposed as a potential adjuvant therapy for infections.},
}
@article {pmid35525370,
year = {2022},
author = {Chen, B and Zhou, S and Zhang, N and Liang, H and Sun, L and Zhao, X and Guo, J and Lu, H},
title = {Micro and nano bubbles promoted biofilm formation with strengthen of COD and TN removal synchronously in a blackened and odorous water.},
journal = {The Science of the total environment},
volume = {},
number = {},
pages = {155578},
doi = {10.1016/j.scitotenv.2022.155578},
pmid = {35525370},
issn = {1879-1026},
abstract = {Blackening and odorization of rivers (BOR) distributed widely in urban cities with high density of human beings. Amounts of pollution control methods have been developed for treatment of these contaminated rivers. Among them, artificial aeration is an effective method for BOR treatment. As a novel developed aeration approach, Micro and nano bubbles (MNBs) takes advances of high specific surface area, high oxygen transfer, long retain time and interface effect. Thus, MNBs aeration was used in an anoxic-oxic (AO) process with traditional activated sludge methods to treat water of BOR in this study. A special designed reactor was made to allow both MNBs and macro bubbles aeration of which mode could be altered easily. The results revealed that MNBs improved removal of COD, NH4+-N and TN distinctly in water of BOR. MNBs provided high dissolved oxygen and promoted the transformation from floc sludge to biofilm. Significant difference between the microbial community of MNBs and macro bubbles sludges was revealed by 16S rRNA amplicon sequencing. Function predictions of MNBs and macro bubbles sludges indicated MNBs enhanced nitrification and aerobic ammonia oxidation without negative impact on denitrification. Moreover, biofilm formed bacteria were enriched by MNBs aeration. This study demonstrated MNBs would be a great potential for the combination of activated sludge and biofilm to treat BOR.},
}
@article {pmid35525049,
year = {2022},
author = {Zhai, S and Cheng, H and Wang, Q and Zhao, Y and Wang, A and Ji, M},
title = {Reinforcement of denitrification in a biofilm electrode reactor with immobilized polypyrrole/anthraquinone-2,6-disulfonate composite cathode.},
journal = {Journal of environmental management},
volume = {315},
number = {},
pages = {115203},
doi = {10.1016/j.jenvman.2022.115203},
pmid = {35525049},
issn = {1095-8630},
abstract = {In biofilm electrode reactors (BER), good nitrate removal performance can be achieved through cooperation of heterotrophic and hydrogen autotrophic denitrification under low carbon/nitrogen conditions. In this study, we proposed a more multifunctional composite cathode, which combine immobilized anthraquinone-2,6-disulphonic disodium salt (AQDS) with polypyrrole (PPy) by electrochemical polymerization-doping method. The nitrate removal performance in BER with PPy/AQDS composite cathode was obviously improved, the nitrate removal rate (4.96 mg/L·h) was almost 2.0 times higher than the control BER system, and relatively stabled nitrate removal efficiency (≥90.0%) was also achieved even as the COD/N of 2.50. Compared with the bare graphite felt, PPy/AQDS coating cathode showed much better electrocatalytic activities, which was more advantageous for in situ production of H2 to support hydrogen autotrophic denitrification process. The PPy-bound AQDS could also act as electron intermediaries, which is beneficial to greatly promote indirect electron process between the denitrifiers and nitrate. Moreover, the PPy/AQDS composite layer formed many particles for improving the specific surface area and bio-attachment site for bacterial attachment, which was conducive for the proliferation of microorganisms and denitrification efficiency. The ratio of biofilm and electrode of PPy/AQDS biocathode was 0.32 ± 0.08, which was 2.46 times than bare electrode (0.13 ± 0.06). Furthermore, enrichment of specific denitrifiers and enhancement of denitrifying enzyme activity was obtained using PPy/AQDS treated electrode, the much higher relative abundance of Thauera of PPy/AQDS biocathode was 1.58 times to the application of bare graphite felt.},
}
@article {pmid35524635,
year = {2022},
author = {Gu, M and Jiang, S and Xu, X and Wu, MY and Chen, C and Yuan, Y and Chen, Q and Sun, Y and Chen, L and Shen, C and Guo, P and Liu, S and Zhao, E and Chen, S and Chen, S},
title = {Simultaneous Photodynamic Eradication of Tooth Biofilm and Tooth Whitening with an Aggregation-Induced Emission Luminogen.},
journal = {Advanced science (Weinheim, Baden-Wurttemberg, Germany)},
volume = {},
number = {},
pages = {e2106071},
doi = {10.1002/advs.202106071},
pmid = {35524635},
issn = {2198-3844},
support = {22005050//National Natural Science Foundation of China/ ; 31925002//National Natural Science Foundation of China/ ; 2019YFA0904300//National Key Research and Development Program of China/ ; WHU2021-YXY00566//Wuhan University/ ; //Karolinska Institutet/ ; },
abstract = {Dental caries is among the most prevalent dental diseases globally, which arises from the formation of microbial biofilm on teeth. Besides, tooth whitening represents one of the fastest-growing areas of cosmetic dentistry. It will thus be great if tooth biofilm eradication can be combined with tooth whitening. Herein, a highly efficient photodynamic dental therapy strategy is reported for tooth biofilm eradication and tooth discoloration by employing a photosensitizer (DTTPB) with aggregation-induced emission characteristics. DTTPB can efficiently inactivate S. mutans, and inhibit biofilm formation by suppressing the expression of genes associated with extracellular polymeric substance synthesis, bacterial adhesion, and superoxide reduction. Its inhibition performance can be further enhanced through combined treatment with chlorhexidine. Besides, DTTPB exhibits an excellent tooth-discoloration effect on both colored saliva-coated hydroxyapatite and clinical teeth, with short treatment time (less than 1 h), better tooth-whitening performance than 30% hydrogen peroxide, and almost no damage to the teeth. DTTPB also demonstrates excellent biocompatibility with neglectable hemolysis effect on mouse red blood cells and almost no killing effect on mammalian cells, which enables its potential applications for simultaneous tooth biofilm eradication and tooth whitening in clinical dentistry.},
}
@article {pmid35524324,
year = {2022},
author = {Matthes, R and Jablonowski, L and Pitchika, V and Holtfreter, B and Eberhard, C and Seifert, L and Gerling, T and Vilardell Scholten, L and Schlüter, R and Kocher, T},
title = {Efficiency of biofilm removal by combination of water jet and cold plasma: an in-vitro study.},
journal = {BMC oral health},
volume = {22},
number = {1},
pages = {157},
pmid = {35524324},
issn = {1472-6831},
mesh = {Biofilms ; *Dental Implants/microbiology ; Humans ; Microscopy, Electron, Scanning ; Pilot Projects ; *Plasma Gases/chemistry ; Surface Properties ; Titanium/chemistry ; Water ; },
abstract = {BACKGROUND: Peri-implantitis therapy is a major problem in implantology. Because of challenging rough implant surface and implant geometry, microorganisms can hide and survive in implant microstructures and impede debridement. We developed a new water jet (WJ) device and a new cold atmospheric pressure plasma (CAP) device to overcome these problems and investigated aspects of efficacy in vitro and safety with the aim to create the prerequisites for a clinical pilot study with these medical devices.<br><br>METHODS: We compared the efficiency of a single treatment with a WJ or curette and cotton swab (CC) without or with adjunctive use of CAP (WJ + CAP, CC + CAP) to remove biofilm in vitro from rough titanium discs. Treatment efficacy was evaluated by measuring turbidity up to 72 h for bacterial re-growth or spreading of osteoblast-like cells (MG-63) after 5 days with scanning electron microscopy. With respect to application safety, the WJ and CAP instruments were examined according to basic regulations for medical devices.<br><br>RESULTS: After 96 h of incubation all WJ and CC treated disks were turbid but 67% of WJ + CAP and 46% CC + CAP treated specimens were still clear. The increase in turbidity after WJ treatment was delayed by about 20 h compared to CC treatment. In combination with CAP the cell coverage significantly increased to 82% (WJ + CAP) or 72% (CC + CAP), compared to single treatment 11% (WJ) or 10% (CC).<br><br>CONCLUSION: The newly developed water jet device effectively removes biofilm from rough titanium surfaces in vitro and, in combination with the new CAP device, biologically acceptable surfaces allow osteoblasts to grow. WJ in combination with CAP leads to cleaner surfaces than the usage of curette and cotton swabs with or without subsequent plasma treatment. Our next step will be a clinical pilot study with these new devices to assess the clinical healing process.},
}
@article {pmid35523645,
year = {2021},
author = {Ma, CJ and He, Y and Jin, X and Zhang, Y and Zhang, X and Li, Y and Xu, M and Liu, K and Yao, Y and Lu, F},
title = {Light-regulated nitric oxide release from hydrogel-forming microneedles integrated with graphene oxide for biofilm-infected-wound healing.},
journal = {Materials science &amp; engineering. C, Materials for biological applications},
volume = {},
number = {},
pages = {112555},
doi = {10.1016/j.msec.2021.112555},
pmid = {35523645},
issn = {1873-0191},
abstract = {Nitric oxide (NO) is an antimicrobial agent that possesses tissue-regenerating ability. However, it also has a short half-life and storage difficulties as disadvantages to its application. To overcome these limitations, a new type of hydrogel-forming microneedle (HFMN) is proposed that can be fabricated by integrating polyvinyl alcohol (PVA) hydrogels (a highly biocompatible drug carrier) with S-nitrosoglutathione (GSNO, a NO releasing agent), and graphene oxide (GO) at freezing temperatures (GO-GNSO-HFMNs). Results show that GSNO-GO-HFMNs release NO gradually with increasing temperature and, more importantly, can be warmed up by mild infrared irradiation to accelerate subcutaneous release of NO from the heat-sensitive GSNO. Biofilm-infected wounds often present obstacles to drug delivery, whereas the microneedle (MN) structure disrupts the biofilm and directly releases NO into the wound. This inhibits bacterial growth and increases tissue regeneration while shortening the healing time of biofilm-infected wounds. Therefore, this type of patch can be regarded as a novel, heat-sensitive, light-regulated, NO-releasing MN patch.},
}
@article {pmid35521519,
year = {2022},
author = {Cohen-Cymberknoh, M and Kolodkin-Gal, D and Keren-Paz, A and Peretz, S and Brumfeld, V and Kapishnikov, S and Suissa, R and Shteinberg, M and McLeod, D and Maan, H and Patrauchan, M and Zamir, G and Kerem, E and Kolodkin-Gal, I},
title = {Calcium carbonate mineralization is essential for biofilm formation and lung colonization.},
journal = {iScience},
volume = {25},
number = {5},
pages = {104234},
pmid = {35521519},
issn = {2589-0042},
abstract = {Biofilms are differentiated microbial communities held together by an extracellular matrix. μCT X-ray revealed structured mineralized areas within biofilms of lung pathogens belonging to two distant phyla - the proteobacteria Pseudomonas aeruginosa and the actinobacteria Mycobacterium abscessus. Furthermore, calcium chelation inhibited the assembly of complex bacterial structures for both organisms with little to no effect on cell growth. The molecular mechanisms promoting calcite scaffold formation were surprisingly conserved between the two pathogens as biofilm development was similarly impaired by genetic and biochemical inhibition of calcium uptake and carbonate accumulation. Moreover, chemical inhibition and mutations targeting mineralization significantly reduced the attachment of P. aeruginosa to the lung, as well as the subsequent damage inflicted by biofilms to lung tissues, and restored their sensitivity to antibiotics. This work offers underexplored druggable targets for antibiotics to combat otherwise untreatable biofilm infections.},
}
@article {pmid35520625,
year = {2022},
author = {Mashamba, TG and Adeosun, IJ and Baloyi, IT and Tshikalange, ET and Cosa, S},
title = {Quorum sensing modulation and inhibition in biofilm forming foot ulcer pathogens by selected medicinal plants.},
journal = {Heliyon},
volume = {8},
number = {4},
pages = {e09303},
pmid = {35520625},
issn = {2405-8440},
abstract = {The crisis of antibiotic resistance necessitates the search of phytochemicals as potential antibacterial, anti-quorum sensing and antibiofilm forming agents. For the present study, fifteen (15) selected medicinal plants were evaluated to inhibit the biological activities of multi-drug resistant (MDR) pathogenic bacteria (Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis) associated with diabetic foot ulcer. Antibacterial activities revealed noteworthy minimum inhibitory concentration (MIC) values ≤1 mg/mL for thirteen (13) out of the sixty (60) plant extracts screened. The potent extracts included Euclea natalensis ethyl acetate (0.25 mg/mL), Aloe ferox methanol (0.5 mg/ml) and Warburgia salutaris aqueous (0.5 mg/mL) extracts. Chemical profiling of the active extracts using gas chromatography-mass spectrometry (GC-MS) identified neophytadiene, guanosine, squalene, cis megastigma-5,8-diene-4-one and sorbitol as prevalent compounds among the active extracts. Anti-quorum sensing activities of E. natalensis (ethyl acetate), A. ferox (methanol) and W. salutaris (aqueous) extracts ranged from 4.81 - 58.34% with E. natalensis (ethyl-acetate) showing the highest activity. Molecular docking against CviR protein showed selected compounds having high docking scores with sorbitol showing the highest score of -7.04 kcal/mol. Warburgia salutaris aqueous extract exhibited the highest biofilm inhibition (73%) against E. coli. Euclea natalensis, Aloe ferox and Warburgia salutaris compounds act as antagonist of N-acyl homoserine lactone (AHL) signaling, thus may serve as candidates in antipathogenic and antibiofilm phytomedicine development for MDR foot ulcer bacterial pathogens.},
}
@article {pmid35515126,
year = {2022},
author = {Huang, J and Wu, Z and Xu, J},
title = {Effects of Biofilm Nano-Composite Drugs OMVs-MSN-5-FU on Cervical Lymph Node Metastases From Oral Squamous Cell Carcinoma.},
journal = {Frontiers in oncology},
volume = {12},
number = {},
pages = {881910},
pmid = {35515126},
issn = {2234-943X},
abstract = {This work was developed to the effects of biofilm composite nano-drug delivery system (OMVs-MSN-5-FU) on lymph node metastasis from oral squamous cell carcinoma. Mesoporous silica nanoparticles loaded with 5-FU (MSN-5-FU) were prepared first. Subsequently, the outer membrane vesicles (OMV) of Escherichia coli were collected to wrap MSN-5-FU, and then OMVs-MSN-5-FU was prepared. It was then immersed in artificial gastric juice and artificial intestinal juice to explore the drug release rate. Next, the effects of different concentrations of the nano-drug delivery systems on the proliferation activity of oral squamous carcinoma cell line KOSC-2 cl3-43 were analyzed. Tumor-bearing nude mice models were prepared by injecting human tongue squamous cell carcinoma cells Tca8113 into BALB/c-nu nude mice. They were injected with the OMVs-MSN-5-FU nano drug carrier system, and peri-carcinoma tissue and cervical lymph node tissue were harvested to observe morphological changes by Hematoxylin - eosin (HE) staining. The scanning electron microscope (SEM) results showed that all MSN, MSN-5-FU, OMV, and OMV-MSN-5-FU were spherical and uniformly distributed, with particle sizes of about 60nm, 80nm, 90nm, and 140nm, respectively. Among them, OMV had a directional core-shell structure. The cumulative drug release rates of artificial gastric juice in 48 hours were 61.2 ± 2.3% and 26.5 ± 3.1%, respectively. The 48 hours cumulative drug release rates of artificial intestinal juice were 70.5 ± 6.3% and 32.1 ± 3.8%, respectively. The cumulative release of MSN-5-FU was always higher than OMV-MSN-5-FU. The cumulative release of MSN-5-FU was always higher than OMV-MSN-5-FU. After injection of OMVS-MSN-5-FU, the number of cancer cells was significantly reduced and cervical lymph node metastasis was significantly controlled. HE staining results showed that OMVS-MSN-5-FU injection reduced the number of stained cells. Dense lymphocytes were clearly observed in the cortex of neck lymphocytes. The OMVs-MSN-5-FU drug delivery system can slow down the drug release rate, significantly inhibit the proliferation activity of oral squamous cancer cells, and control the metastasis of cancer cells to cervical lymph nodes.},
}
@article {pmid35513339,
year = {2022},
author = {Dietrich, PM and Kjærvik, M and Willneff, EA and Unger, WES},
title = {In-depth analysis of iodine in artificial biofilm model layers by variable excitation energy XPS and argon gas cluster ion sputtering XPS.},
journal = {Biointerphases},
volume = {17},
number = {3},
pages = {031002},
doi = {10.1116/6.0001812},
pmid = {35513339},
issn = {1559-4106},
mesh = {Argon/chemistry ; Biofilms ; Iodides ; *Iodine ; Photoelectron Spectroscopy ; Povidone ; *Povidone-Iodine ; Sepharose ; },
abstract = {Here, we present a study on agarose thin-film samples that represent a model system for the exopolysaccharide matrix of biofilms. Povidone-iodide (PVP-I) was selected as an antibacterial agent to evaluate our x-ray photoelectron spectroscopy (XPS)-based methodology to trace specific marker elements, here iodine, commonly found in organic matrices of antibiotics. The in-depth distribution of iodine was determined by XPS analyses with variable excitation energies and in combination with argon gas cluster ion beam sputter cycles. On mixed agarose/PVP-I nanometer-thin films, both methods were found to solve the analytical task and deliver independently comparable results. In the mixed agarose/PVP-I thin film, we found the outermost surface layer depleted in iodine, whereas the iodine is homogeneously distributed in the depth region between this outermost surface layer and the interface between the thin film and the substrate. Depletion of iodine from the uppermost surface in the thin-film samples is assumed to be caused by ultrahigh vacuum exposure resulting in a loss of molecular iodine (I2) as reported earlier for other iodine-doped polymers.},
}
@article {pmid35512440,
year = {2022},
author = {Li, Y and Sun, W and Wang, Q and Yu, Y and Wan, Y and Zhou, K and Guo, R and Han, X and Chen, Z and Fang, W and Jiang, W},
title = {The GntR-like transcriptional regulator HutC involved in motility, biofilm-forming ability, and virulence in Vibrio parahaemolyticus.},
journal = {Microbial pathogenesis},
volume = {167},
number = {},
pages = {105546},
doi = {10.1016/j.micpath.2022.105546},
pmid = {35512440},
issn = {1096-1208},
abstract = {As a halophilic food-borne pathogen, Vibrio parahaemolyticus continueo be a major health issue worldwide. The pathogenic mechanisms of V. parahaemolyticus are still not fully understood. One of the most abundant and widely distributed groups of helix-turn-helix transcription factors is the GntR family of regulators, which are involved in the regulation of various biological processes in bacteria, but little is known about their functions in V. parahaemolyticus. Here, we identified a gene designated as hutC in V. parahaemolyticus SH112 that encodes a member belongs to the HutC subfamily of the large GntR transcriptional regulator family. Compared to the wild type, the hutC mutant strain was significantly more sensitive to acid, bile salt, Triton X-100, and sodium dodecyl sulfate stresses. Our results showed that HutC is required for optimal swimming motility but not necessary for the swarming of V. parahaemolyticus. In addition, inactivation of hutC in V. parahaemolyticus SH112 led to decreased biofilm formation, reduced cytotoxicity in Coca-2 cells, and defective virulence in vivo compared to the wild-type strain. Furthermore, transcriptome sequencing (RNA-Seq) analysis and real-time PCR indicated 4 upregulated and 14 downregulated genes in the hutC mutant strain. Functional analysis revealed that 4 upregulated genes were related to the histidine metabolism pathway. The 14 downregulated genes were mostly related to the cellular metabolic process, binding, and membrane part. This study presents evidence that HutC is involved in bacterial survival under conditions of stress, swimming motility, biofilm formation, cytotoxicity, virulence, and gene regulation of V. parahaemolyticus during infection.},
}
@article {pmid35512342,
year = {2022},
author = {Boncompagni, SR and Micieli, M and Di Maggio, T and Aiezza, N and Antonelli, A and Giani, T and Padoani, G and Vailati, S and Pallecchi, L and Rossolini, GM},
title = {Activity of fosfomycin/colistin combinations against planktonic and biofilm Gram-negative pathogens.},
journal = {The Journal of antimicrobial chemotherapy},
volume = {},
number = {},
pages = {},
doi = {10.1093/jac/dkac142},
pmid = {35512342},
issn = {1460-2091},
support = {//Zambon S.p.A./ ; },
abstract = {OBJECTIVES: To investigate the in vitro activity of fosfomycin, colistin and combinations thereof against planktonic and biofilm cultures of Gram-negative pathogens, mostly showing MDR phenotypes, at concentrations achievable via inhalation of aerosolized drugs.<br><br>METHODS: Activity against planktonic cultures was tested by the chequerboard assay with 130 strains, including 52 Pseudomonas aeruginosa, 47 Klebsiella pneumoniae, 19 Escherichia coli, 7 Stenotrophomonas maltophilia and 5 Acinetobacter baumannii. Activity against biofilm cultures was tested by biofilm chequerboard and quantitative antibiofilm assays with a subset of 20 strains. In addition, 10 of these strains were tested in mutant prevention concentration (MPC) assays.<br><br>RESULTS: Against planktonic cultures, synergism between fosfomycin and colistin was detected with a minority (10%) of strains (eight K. pneumoniae and five P. aeruginosa), while antagonism was never observed. Synergism between fosfomycin and colistin against biofilms was observed with the majority of tested strains (16/20 in biofilm chequerboard assays, and 18/20 in the quantitative antibiofilm assays), including representatives of each species and regardless of their resistance genotype or phenotype. Furthermore, combination of fosfomycin and colistin was found to significantly reduce the MPC of individual drugs.<br><br>CONCLUSIONS: Fosfomycin and colistin in combination, at concentrations achievable via inhalation of nebulized drugs, showed notable synergy against MDR Gram-negative pathogens grown in biofilm, and were able to reduce the emergence of fosfomycin- and colistin-resistant subpopulations.},
}
@article {pmid35511298,
year = {2022},
author = {Jia, X and Liu, X and Zhu, K and Zheng, X and Yang, Z and Yang, X and Hou, Y and Yang, Q},
title = {Lysozyme regulates the extracellular polymer of activated sludge and promotes the formation of electroactive biofilm.},
journal = {Bioprocess and biosystems engineering},
volume = {45},
number = {6},
pages = {1065-1074},
pmid = {35511298},
issn = {1615-7605},
support = {No. 202017//Foundation of Qilu University of Technology of Cultivating Subject for Biology and Biochemistry/ ; No. S202010431030//National Innovation and Entrepreneurship Training Program for Local College Student/ ; No. S202010431046//National Innovation and Entrepreneurship Training Program for Local College Student/ ; },
mesh = {Biofilms ; *Extracellular Polymeric Substance Matrix ; Muramidase ; Polymers ; *Sewage/microbiology ; },
abstract = {The formation of electroactive biofilm from activated sludge on electrode surface is a key step to construct a bio-electrochemical system, yet it is greatly limited by the poor affinity between the bacteria and the electrode interface. Herein, we report a new method to promote the formation of electroactive biofilm by regulating the extracellular polymeric substance (EPS) content in activated sludge with lysozyme. The investigation of the effect of lysozyme treatment on the content of extracellular polymers and the biofilm formation of electroactive bacteria suggests that lysozyme can improve the permeability of the positive bacterial cell membrane and thus increase the EPS content in the activated sludge. The characterizations of electrochemical activity, surface morphology and community structure of the anode biofilm indicate that increasing EPS content promotes the adhesion of the mixed bacteria in the activated sludge on the electrode and results in denser biofilms with better conductivities. The microbial fuel cell (MFC) inoculated with the sludge of high EPS content exhibits the power density up to 2.195 W/m2, much higher than that inoculated with the untreated sludge (1.545 W/m2). The strategy of adjusting EPS content in activated sludge with a biological enzyme can effectively enhance the ability of the bacterial community to form biofilms and exhibits great application potentials in the construction of high efficiency bio-electrochemical systems.},
}
@article {pmid35511205,
year = {2022},
author = {Patil, JS and D'souza, S},
title = {Dark survival in biofilm-forming microalgae: potential for colonizing benthic ecosystems.},
journal = {FEMS microbiology ecology},
volume = {},
number = {},
pages = {},
doi = {10.1093/femsec/fiac053},
pmid = {35511205},
issn = {1574-6941},
abstract = {The biofilm-forming microalgae are known to experience periods of continuous darkness (upto several days), in addition to the natural day-night cycle, especially in the intertidal sediment regions (when transported to deeper sediments) and the ships' ballast water tanks (during voyages). However, the information on community and physiological responses to different periods of darkness is limited. Here, the survival capability of biofilm-forming microalgae to varying periods of darkness (7-35 days) and the growth patterns upon resumption of normal 12h light:dark photocycle has been addressed through simulation experiments. Diatoms dominated the seawater biofilms, but the dark survival period varied and was species-specific. Of the 25 diatoms, only Amphora, potential toxin producer, followed by Navicula remained viable and photosynthetically healthy under darkness without undergoing asexual reproduction. Both diatoms are essential contributors to fouling and microphytobenthic community. Upon re-exposure of dark-adapted biofilms to 12h light:dark photocycle, the improvement in photosynthetic efficiency and resumption of growth via asexual-reproduction was observed. However, the lag-phase duration increased with a long dark history. Nevertheless, eurytolerant nature and high dark survival capability (with its quick response to light) of Amphora and Navicula indicated that they have the potential to colonize benthic-ecosystems thus impacting the benthic and fouling community.},
}
@article {pmid35510054,
year = {2022},
author = {Li, G and Wei, Y and Guo, Y and Gong, H and Lian, J and Xu, G and Bai, B and Yu, Z and Deng, Q},
title = {Omadacycline Efficacy against Streptococcus Agalactiae Isolated in China: Correlation between Resistance and Virulence Gene and Biofilm Formation.},
journal = {Computational intelligence and neuroscience},
volume = {2022},
number = {},
pages = {7636983},
pmid = {35510054},
issn = {1687-5273},
mesh = {*Biofilms ; China ; Multilocus Sequence Typing ; Retrospective Studies ; *Streptococcus agalactiae/genetics ; Tetracyclines ; Virulence/genetics ; },
abstract = {This study aimed to evaluate the activity, resistance, clonality of MIC distribution, and the correlation between virulence and resistance genes and biofilm formation of omadacycline (OMC) in clinics for Streptococcus agalactiae isolates from China. 162 isolates were collected retrospectively in China. The S. agalactiae were collected from the body's cervical secretions, wound secretions, ear swabs, secretions, semen, venous blood, cerebrospinal fluid, pee, etc. The MIC of OMC against S. agalactiae was determined by broth microdilution. The inhibition zone diameters of OMC and other common antibiotics were measured using filter paper. D-test was performed to determine the phenotype of cross resistance between erythromycin and clindamycin. In Multilocus sequence typing (MLST), some commonly-detected resistance genes and virulence gene of these S. agalactiae isolates were investigated using polymerase chain reaction (PCR). Biofilms were detected by crystal violet staining. Our data demonstrated the correalation of the biofilm formation and OMA antimicrobial susceptibility of S.agalactiae clinical isolates with the carrier of virulence gene scpB. Conclusively, OMC exhibits the robust antimcirobial activity against clinical S. agalactiae isolates from China compared with DOX or MIN, and the carrier of the virulence gene scpB might correlate with the biofilm formation in OMC-resistant S. agalactiae.},
}
@article {pmid35508743,
year = {2022},
author = {ElBaradei, A and Yakout, MA},
title = {Stenotrophomonas maltophilia: Genotypic Characterization of Virulence Genes and The Effect of Ascorbic Acid on Biofilm Formation.},
journal = {Current microbiology},
volume = {79},
number = {6},
pages = {180},
pmid = {35508743},
issn = {1432-0991},
mesh = {Ascorbic Acid/pharmacology ; Biofilms ; *Gram-Negative Bacterial Infections/microbiology ; Humans ; *Stenotrophomonas maltophilia/genetics ; Virulence/genetics ; },
abstract = {Stenotrophomonas maltophilia is an environmental bacterium that has gained a lot of attention, as a nosocomial pathogen associated with significant mortality rates. Biofilm formation is considered the corner stone for establishing infections in many bacteria including S. maltophilia. The aim of this study was the genotypic characterization of the different virulence-associated genes and the investigation of the effect of ascorbic acid on S. maltophilia biofilm formation. A total of 20 S. maltophilia isolates from different sources were included in this study. Genes encoding different virulence factors were investigated genotypically. These included stmPr1, stmPr2, smlt3773 locus, smf-1, rpfF, rmlA and spgM. Biofilm formation was investigated phenotypically. The effect of ascorbic acid on biofilm formation was investigated using MIC as well as sub-inhibitory concentrations. Many of the isolates harbored both serine proteases genes stmPr-1 and stmPr-2. Fourteen (70%) of the 20 isolates carried stmPr-1 and 15 (75%) had stmPr-2. Most of the isolates (95%) possessed smlt-3773 locus. Genes linked to biofilm formation such as smf-1, rpfF, rmlA and spgM, were found in (90%), (45%), (85%) and (30%) of the isolates, respectively. Phenotypically, all S. maltophilia isolates (100%) were biofilm producers. Fifteen (75%) were strong biofilm producers and 5 (25%) were moderate biofilm producers. In attempts to seek a non-chemotherapeutic alternative that can hinder biofilm formation without provoking antimicrobial resistance, the results, herein, showed that ascorbic acid inhibits biofilm formation in a dose-dependent manner.},
}
@article {pmid35508567,
year = {2022},
author = {Keymaram, M and Falahati, M and Farahyar, S and Lotfali, E and Abolghasemi, S and Mahmoudi, S and Sadeghi, F and Khalandi, H and Ghasemi, R and Shamsaei, S and Raiesi, O},
title = {Anti-biofilm properties of eucalyptol in combination with antifungals against Candida albicans isolates in patients with hematological malignancy.},
journal = {Archives of microbiology},
volume = {204},
number = {6},
pages = {295},
pmid = {35508567},
issn = {1432-072X},
support = {IR.IUMS.FMD.REC.1399.393.//Iran University of Medical Sciences/ ; },
mesh = {Adult ; Amphotericin B/pharmacology/therapeutic use ; Antifungal Agents/pharmacology/therapeutic use ; Biofilms ; Candida ; Candida albicans ; *Candidiasis, Oral/drug therapy ; Eucalyptol ; Female ; *Hematologic Neoplasms/complications/drug therapy ; Humans ; Itraconazole/pharmacology ; Male ; Microbial Sensitivity Tests ; Middle Aged ; Nystatin/pharmacology ; },
abstract = {Oral candidiasis is a fungal infection caused mainly by Candida albicans and it is a major problem among hematologic malignancy patients. Biofilm formation is an attributable factor to both virulence and drug resistance of Candida species. The aim of the study was to evaluate the biofilm-producing ability of oral C. albicans isolates and to evaluate the inhibitory activity of eucalyptol on Candida biofilm, alone and in combination with antifungal agents. Samples were collected from the oral cavity of 106 patients with hematologic malignancy. The isolated yeasts were identified by PCR-sequencing. Then C. albicans isolates were analyzed for their biofilm-producing ability by crystal violet staining and MTT assay. The minimum biofilm inhibition concentrations (MBIC) of eucalyptol, amphotericin B, itraconazole, and nystatin and the in vitro interaction of eucalyptol with these drugs were tested according to CLSI-M-27-A3 protocol and checkerboard methods, respectively. From 106 patients, 50 (47.2%) were confirmed for oral candidiasis [mean ± SD age 39 ± 14 years; female 31 (62%) and male 19 (38%)]. C. albicans was isolated from 40 of 50 (80%) patients. From 40 C. albicans isolates, 24 (60%) and 16 (40%) were moderate and weak biofilm producer, respectively. The geometric mean MBIC of amphotericin B, itraconazole, nystatin and eucalyptol were 3.93 µg/mL, 12.55 µg/mL, 0.75 µg/mL and 798 µg/mL, respectively. Eucalyptol interacted synergistically with amphotericin B, itraconazole and nystatin against 12.5, 10, and 22.5% of isolates, respectively. Eucalyptol demonstrated promising activity against biofilm of C. albicans when tested alone or combined with antifungal drugs.},
}
@article {pmid35508261,
year = {2022},
author = {Cao, X and Yuan, Y and Khodseewong, S and Nishimura, O and Wang, H and Li, X},
title = {Efficient use of electrons in a double-anode microbial fuel cell-biofilm electrode reactor self-powered coupled system for degradation of azo dyes.},
journal = {Chemosphere},
volume = {302},
number = {},
pages = {134760},
doi = {10.1016/j.chemosphere.2022.134760},
pmid = {35508261},
issn = {1879-1298},
abstract = {A coupled system consisting of a double-anode microbial fuel cell (MFC) unit and a biofilm electrode reactor (BER) has been applied to degrade the azo dye reactive brilliant red X-3B. In this system, the MFC effluent was used as the input of the BER. The MFC preliminarily degraded X-3B while generating electricity, and the BER obtained electrons from the MFC through the external circuit to continue degrading pollutants without the need for an external power supply. The X-3B removal efficiency was 41.93% higher in the coupled system than the control when the X-3B concentration was 3000 mg/L. The analysis of intermediate products showed that the azo bond of X-3B broke in the MFC, generating a large number of complex intermediates such as anthraquinones, which were further degraded into simple organic compounds in the BER. Meanwhile, the abundance of microbial taxa related to the degradation of refractory organics in the MFC was high, as was that of microbial taxa related to the degradation of simple organics in the BER. Furthermore, the abundance of microorganisms related to power generation in the MFC increased. These results provided an efficient strategy for improving electron utilization efficiency in the coupling system of bioelectrochemical system.},
}
@article {pmid35507795,
year = {2022},
author = {Khan, F},
title = {Strategies for controlling biofilm-forming microbial pathogens on biotic and abiotic surfaces.},
journal = {Current drug targets},
volume = {},
number = {},
pages = {},
doi = {10.2174/1389450123666220429115255},
pmid = {35507795},
issn = {1873-5592},
}
@article {pmid35507525,
year = {2022},
author = {Mayorga-Martinez, CC and Zelenka, J and Klima, K and Mayorga-Burrezo, P and Hoang, L and Ruml, T and Pumera, M},
title = {Swarming Magnetic Photoactive Microrobots for Dental Implant Biofilm Eradication.},
journal = {ACS nano},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsnano.2c02516},
pmid = {35507525},
issn = {1936-086X},
abstract = {Titanium dental implants are a multibillion dollar market in the United States alone. The growth of a bacterial biofilm on a dental implant can cause gingivitis, implant loss, and expensive subsequent care. Herein, we demonstrate the efficient eradication of dental biofilm on titanium dental implants via swarming magnetic microrobots based on ferromagnetic (Fe3O4) and photoactive (BiVO4) materials through polyethylenimine micelles. The ferromagnetic component serves as a propulsion force using a transversal rotating magnetic field while BiVO4 is the photoactive generator of reactive oxygen species to eradicate the biofilm colonies. Such photoactive magnetically powered, precisely navigated microrobots are able to destroy biofilm colonies on titanium implants, demonstrating their use in precision medicine.},
}
@article {pmid35507414,
year = {2022},
author = {Cui, S and Qiao, J and Xiong, MP},
title = {Antibacterial and Biofilm-Eradicating Activities of pH-Responsive Vesicles against Pseudomonas aeruginosa.},
journal = {Molecular pharmaceutics},
volume = {},
number = {},
pages = {},
doi = {10.1021/acs.molpharmaceut.2c00165},
pmid = {35507414},
issn = {1543-8392},
abstract = {The formation of biofilms by a microcolony of bacteria is a significant burden on the healthcare industry due to difficulty eradicating it. In this study, pH-responsive vesicles capable of releasing apramycin (APR), a model aminoglycoside antibiotic, in response to the low pH typical of establishedPseudomonas aeruginosa biofilms resulted in improved eradication of existing biofilms in comparison to the free drug. The amphiphilic polymeric vesicle (PV) comprised of block polymer poly (ethylene glycol)-block-poly 2-(dimethylamino) ethyl methacrylate (mPEG-b-pDEAEMA) averaged 128 nm. The drug encapsulation content of APR in PV/APR was confirmed to be 28.2%, and the drug encapsulation efficiency was confirmed to be 51.2%. At pH 5.5, PV/APR released >90% APR after 24 h compared to <20% at pH 7.4. At pH 5.5, protonation of the pDEAEMA block results in a zeta potential of +23 mV compared to a neutral zeta potential of +2.2 mV at pH 7.4. Confocal microscopy, flow cytometry, and scanning electron microscopy reveal that the positively charged vesicles can compromise the integrity of the planktonic bacterial membrane in a pH-dependent manner. In addition, PV/APR is able to diffuse into mature biofilms to release APR in the acidic milieu of biofilm bacteria, and PV/APR was more efficient at eliminating preexisting biofilms compared to free APR at 128 and 256 μg/mL. This study reveals that dynamic charge density in response to pH can lead to differential levels of interactions with the biofilm and bacterial membrane. This effectively results in enhanced antibacterial and antibiofilm properties against both planktonic and difficult-to-treat biofilm bacteria at concentrations significantly lower than those of the free drug. Overall, this pH-responsive vesicle could be especially promising for treating biofilm-associated infectious diseases.},
}
@article {pmid35507240,
year = {2022},
author = {Shukla, SK and Manobala, T and Rao, TS},
title = {The role of S-layer protein (SlpA) in biofilm-formation of Deinococcus radiodurans.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/jam.15613},
pmid = {35507240},
issn = {1365-2672},
abstract = {AIMS: To investigate the molecular basis of biofilm formation in a recombinant lab strain of Deinococcus radiodurans with a plasmid harbouring gfp and kanR that acquired the biofilm-forming ability.<br><br>METHODS AND RESULTS: Deinococcus radiodurans R1 is known as a nonbiofilm former bacterium and so far there are no reports on its biofilm-producing capabilities. In this study, we investigated the molecular basis of biofilm formation in a recombinant strain of D. radiodurans using classical biofilm assays, confocal laser scanning microscopy and real-time PCR. Biochemical analysis of D. radiodurans biofilm matrix revealed that it consisted predominantly of protein and carbohydrate complexes with a little amount of extracellular DNA (eDNA). Furthermore, studies showed that D. radiodurans biofilm formation was enhanced in the presence of 25 mM Ca2+ , which enhanced the exopolysaccharide and protein content in the biofilm matrix. Enzymatic treatments with proteinase K, alginate lyase and DNase I indicated the involvement of some proteinaceous components to be critical in the biofilm formation. RT-PCR studies showed that increased expression of a surface layer protein SlpA conferred the biofilm ability to D. radiodurans.<br><br>CONCLUSION: Overexpression of SlpA in D. radiodurans conferred the biofilm formation ability to the bacterium, in which a partial role was also played by the recombinant plasmid pKG. It was also shown that the presence of Ca2+ in the growth medium enhanced SlpA production, thus improving biofilm stability and biofilm maturation of D. radiodurans.<br><br>SIGNIFICANCE AND IMPACT: This study shows how biofilm formation can be augmented in D. radiodurans. The finding has implications for the development of D. radiodurans biofilm-based biotechnological applications.},
}
@article {pmid35506966,
year = {2022},
author = {Abdul Azees, PA and Wang, H and Chen, XD and Yeh, CK and Garcia-Godoy, F},
title = {In vitro effect of an oral spray and mouthrinses on dual species cariogenic bacteria biofilm.},
journal = {American journal of dentistry},
volume = {35},
number = {2},
pages = {103-108},
pmid = {35506966},
issn = {0894-8275},
mesh = {*Biofilms ; Dental Enamel ; Humans ; Mouthwashes/pharmacology ; Oral Sprays ; *Streptococcus mutans ; },
abstract = {PURPOSE: To determine the efficacy of an oral spray and oral rinses to inhibit oral cariogenic dual species biofilm formation on hydroxyapatite (HA) discs.<br><br>METHODS: The Streptococcus mutans (NCTC 10449, ATCC), Lactobacilli casei (NCIB 8820, ATCC) dual species biofilm formation and inhibition on HA disc was tested using five antimicrobial products, i.e., oral spray (Oral Shield), Mouthrinse (Listerine Ultra Clean, Listerine Cool Mint, Crest Pro-Health, ACT Restoring). An untreated group served as control. The established biofilm on the surface of each disc was treated or untreated with oral spray and mouthrinse for 2 minutes after 24 or 48 hours. The dual species biofilm formation and inhibition on HA discs was determined using the spread plate method and colonies were counted and expressed as colony forming units (CFU/mL). Further, the HA disc was subjected to confocal laser scanning microscope (CLSM) examination to determine the viability of cells using live-dead staining and a scanning electron microscope (SEM) to examine the effect on bacteria biofilm and morphology. The cytotoxic effect of test spray and mouthrinse was tested on OKF6/TERT-2 cells using the MTT method.<br><br>RESULTS: At each time point, 24- or 48-hours, S. mutans and L. casei mixed biofilm on HA discs had a significantly (P> 0.001) fewer number of bacteria in the treated groups than the untreated one. The oral spray and mouthrinses had a detrimental effect on bacteria biofilm, morphology and cell wall, whereas no significant changes were observed in the untreated group. Cytotoxic assay revealed that the oral spray was safe for human oral keratinocyte cells.<br><br>CLINICAL SIGNIFICANCE: The tested oral spray could offer potential to inhibit the cariogenic bacteria and protect the tooth enamel from cariogenic bacterial biofilm.},
}
@article {pmid35505905,
year = {2022},
author = {Visperas, A and Santana, D and Ju, M and Milbrandt, NB and Tsai, YH and Wickramasinghe, S and Klika, AK and Piuzzi, NS and Samia, ACS and Higuera-Rueda, CA},
title = {Standardized quantification of biofilm in a novel rabbit model of periprosthetic joint infection.},
journal = {Journal of bone and joint infection},
volume = {7},
number = {2},
pages = {91-99},
pmid = {35505905},
issn = {2206-3552},
abstract = {Periprosthetic joint infection (PJI) is one of the most devastating complications of total joint arthroplasty. The underlying pathogenesis involves the formation of bacterial biofilm that protects the pathogen from the host immune response and antibiotics, making eradication difficult. The aim of this study was to develop a rabbit model of knee PJI that would allow reliable biofilm quantification and permit the study of treatments for PJI. In this work, New Zealand white rabbits (n = 19) underwent knee joint arthrotomy, titanium tibial implant insertion, and inoculation with Xen36 (bioluminescent Staphylococcus aureus) or a saline control after capsule closure. Biofilm was quantified via scanning electron microscopy (SEM) of the tibial explant 14 d after inoculation (n = 3 noninfected, n = 2 infected). Rabbits underwent debridement, antibiotics, and implant retention (DAIR) (n = 6) or sham surgery (n = 2 noninfected, n = 6 infected) 14 d after inoculation, and they were sacrificed 14 d post-treatment. Tibial explant and periprosthetic tissues were examined for infection. Laboratory assays supported bacterial infection in infected animals. No differences in weight or C-reactive protein (CRP) were detected after DAIR compared to sham treatment. Biofilm coverage was significantly decreased with DAIR treatment when compared with sham treatment (61.4 % vs. 90.1 %, p < 0 .0011) and was absent in noninfected control explants. In summary, we have developed an experimental rabbit hemiarthroplasty knee PJI model with bacterial infection that reliably produces quantifiable biofilm and provides an opportunity to introduce treatments at 14 d. This model may be used to better understand the pathogenesis of this condition and to measure treatment strategies for PJI.},
}
@article {pmid35503968,
year = {2022},
author = {Ramidan, JC and Bertolini, MME and Júnior, MRM and Portela, MB and Lourenço, EJV and Telles, DM},
title = {Filling Materials Efficacy on Preventing Biofilm Formation inside Srew Acess Channnels of Implant Abutments.},
journal = {The Journal of oral implantology},
volume = {},
number = {},
pages = {},
doi = {10.1563/aaid-joi-D-20-00191},
pmid = {35503968},
issn = {0160-6972},
abstract = {The choice of material used to fill screw access channels in implant-supported prostheses depends, in most cases, on operator's preference, without considering the susceptibility of biofilm colonization. Therefore, the aim of this study was to determine and compare the total amount of biofilm formed on different materials used to fill screw access channels in implant abutments. For this propose, titanium implant analogs were attached on abutments and divided into 5 groups: positive control (no filling material); negative control (closed with resin); filled with cotton, gutta-percha, or polytetrafluoroethylene-PTFE. The analogs with attached abutments were then immersed in a brain heart infusion medium containing Candida albicans (ATCC 10231) and incubated aerobically at 37°C with gentle agitation. After 15 days, materials were removed and total viable biofilm on each material was quantified by methyl tetrazolium (MTT) reduction assay at 490nm. All experiments were performed in triplicate. Data were processed by IBM SPSS Statistic software using one-way ANOVA and Bonferroni pos hoc tests to analyze differences between groups, with overall significance level=.05 (P<.001). A significant difference was observed between cotton and gutta-percha (P<.017) and between cotton and PTFE (P<.025). However, there was no statistical difference between gutta-percha and PTFE (P>.050). Thus, this in vitro experiment showed that gutta-percha and PTFE presented lower biofilm formation in comparison with cotton when used to fill screw access channels. These results can provide a basis for future clinical studies that can be a guide to decreasing the occurrence of gaps and bacterial growth inside the implant/abutment attachment site. In addition, controlled in vivo studies are necessary to confirm the clinical viability of findings of this study.},
}
@article {pmid35503533,
year = {2022},
author = {Leshem, T and Schnall, BS and Azrad, M and Baum, M and Rokney, A and Peretz, A},
title = {Incidence of biofilm formation among MRSA and MSSA clinical isolates from hospitalized patients in Israel.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/jam.15612},
pmid = {35503533},
issn = {1365-2672},
abstract = {AIM: To assess the biofilm-producing capacities of Staphylococcus aureus strains isolated from hospitalized patients in Israel.<br><br>METHODS AND RESULTS: A total of 16 S. aureus (80 MRSA and 83 MSSA) from screening (nasal swab) and clinical samples (blood and wounds) were characterized. Biofilm-producing capacities were determined using two different biofilm detection assays: Congo Red agar (CRA) and microtiter plate (MtP). In addition, a real-time PCR analysis was performed to detect the presence of biofilm-associated genes (icaA and icaD) and mecA gene. The two assays showed similar biofilm production pattern (28.2% agreement). MRSA strains tended to be greater biofilm-producers than MSSA strains. The presence of mecA was associated with biofilm production (p = 0.030). Additionally, bacteria isolated from blood samples produced less biofilm compared to those from other sources. Finally, no association was found between icaA and icaD presence and biofilm production.<br><br>CONCLUSION: This study supports earlier assumptions that biofilm formation depends strongly on environmental conditions.<br><br>This study significantly improved our knowledge on the biofilm production capacity of S. aureus strains in Israel. Moreover, it revealed an association between the mecA gene and biofilm production. Finally, this study underscores the importance of further research to evaluate risk factors for biofilm production.},
}
@article {pmid35500834,
year = {2022},
author = {Fu, HM and Wang, J and Ren, H and Ding, L},
title = {Acceleration of start-up of moving bed biofilm reactor at low temperature by adding specialized Quorum Sensing bacteria.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {127249},
doi = {10.1016/j.biortech.2022.127249},
pmid = {35500834},
issn = {1873-2976},
abstract = {This study aims to accelerate biofilm formation and operational performance of moving bed biofilm reactor (MBBR) at 5 ℃ by adding specialized Quorum Sensing bacteria (sphingomonas rubra BH3T). Results showed that bio augmented MBBR (RS) achieved a higher chemical oxygen demand and NH4+-N removal rate (93% and 75%), which in accordance with its increased biofilm thickness, higher biofilm activity, and nitrifying bacteria abundance (Nitrospira). The increased biofilm thickness (60.23 %) during the whole operating time, accompanied by more potent adhesion force (61.59 %), was related to increased polysaccharides and proteins in the biofilm. Pyrosequencing analysis indicated that BH3T contributed to higher species richness and triggered the rapid growth of precursor microorganisms (Nakamurella, Micropruina, and Zoogloea) and the enrichment of multifunctional microorganisms (Pseudomonas, Aeromonas, Arcobacter, Dechloromonas, and Flavobacterium) at low temperatures. This study provides an economical and practical new insight into accelerating start-up of MBBR system at low temperature.},
}
@article {pmid35499217,
year = {2022},
author = {Shahroodian, S and Mirshekar, M and Talebi, M and Torki, A and Amirmozafari, N},
title = {Association between virulence factors and biofilm formation in Enterococcus faecalis isolated from semen of infertile men.},
journal = {American journal of reproductive immunology (New York, N.Y. : 1989)},
volume = {},
number = {},
pages = {},
doi = {10.1111/aji.13561},
pmid = {35499217},
issn = {1600-0897},
abstract = {PROBLEM: Enterococcus faecalis is a common microbial semen contaminant. Although virulence factors and biofilm formation have often been analyzed in Enterococcus spp., there is little information about these features in isolates obtained from the genitourinary tract. This study was intended to characterize and determine the relationship between biofilm-forming ability and the presence of E. faecalis virulence factors isolated from human semen.<br><br>METHOD OF STUDY: A total of 32 patients diagnosed with primary infertility and 28 healthy men were included in the study. Semen analyses were performed according to the WHO guidelines. PCR reactions were applied for the detection of ace, esp, efeA, gelE, asa1, and cylA genes. Microtiter plate assay, via measurement of OD560, was used to measure the biofilm-forming ability of the isolates.<br><br>RESULTS: Sixty E. faecalis isolates from semen of infertile and fertile men were characterized by phenotypic and genotypic methods. The prevalence of ace, esp, efeA, gelE, asa1 and cylA were reported to be 81.3%/100.0%, 81.3%/89.3%, 81.3%/85.7%, 71.9%/53.6%, 8.8%/75.0%, and 62.5%/67.9% in infertile/fertile groups; respectively. Strong, weak, and non-biofilm reactions were reported to be 50.0%/21.4%, 40.6%/64.3%, and 9.4%/14.3% in infertile and fertile groups; respectively.<br><br>CONCLUSIONS: There was a significant relationship between fertility and weak biofilm reaction and also between biofilm formation and possession of the esp gene (P < 0.05). It could be speculated that colonization with E. faecalis with a strong ability for biofilm formation could become a potential threat to men's fertility. This article is protected by copyright. All rights reserved.},
}
@article {pmid35495696,
year = {2022},
author = {Li, M and Wang, Z and Zhou, M and Zhang, C and Zhi, K and Liu, S and Sun, X and Wang, Z and Liu, J and Liu, D},
title = {Continuous Production of Human Epidermal Growth Factor Using Escherichia coli Biofilm.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {855059},
pmid = {35495696},
issn = {1664-302X},
abstract = {Increasing demand for recombinant proteins necessitates efficient protein production processes. In this study, a continuous process for human epidermal growth factor (hEGF) secretion by Escherichia coli was developed by taking advantage of biofilm formation. Genes bcsB, fimH, and csgAcsgB that have proved to facilitate biofilm formation and some genes moaE, yceA, ychJ, and gshB potentially involved in biofilm formation were examined for their effects on hEGF secretion as well as biofilm formation. Finally, biofilm-based fermentation processes were established, which demonstrated the feasibility of continuous production of hEGF with improved efficiency. The best result was obtained from ychJ-disruption that showed a 28% increase in hEGF secretion over the BL21(DE3) wild strain, from 24 to 32 mg/L. Overexpression of bcsB also showed great potential in continuous immobilized fermentation. Overall, the biofilm engineering here represents an effective strategy to improve hEGF production and can be adapted to produce more recombinant proteins in future.},
}
@article {pmid35495689,
year = {2022},
author = {Chang, C and Yu, X and Guo, W and Guo, C and Guo, X and Li, Q and Zhu, Y},
title = {Bacteriophage-Mediated Control of Biofilm: A Promising New Dawn for the Future.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {825828},
pmid = {35495689},
issn = {1664-302X},
abstract = {Biofilms are complex microbial microcolonies consisting of planktonic and dormant bacteria bound to a surface. The bacterial cells within the biofilm are embedded within the extracellular polymeric substance (EPS) consisting mainly of exopolysaccharides, secreted proteins, lipids, and extracellular DNA. This structural matrix poses a major challenge against common treatment options due to its extensive antibiotic-resistant properties. Because biofilms are so recalcitrant to antibiotics, they pose a unique challenge to patients in a nosocomial setting, mainly linked to lower respiratory, urinary tract, and surgical wound infections as well as the medical devices used during treatment. Another unique property of biofilm is its ability to adhere to both biological and man-made surfaces, allowing growth on human tissues and organs, hospital tools, and medical devices, etc. Based on prior understanding of bacteriophage structure, mechanisms, and its effects on bacteria eradication, leading research has been conducted on the effects of phages and its individual proteins on biofilm and its role in overall biofilm removal while also revealing the obstacles this form of treatment currently have. The expansion in the phage host-species range is one that urges for improvement and is the focus for future studies. This review aims to demonstrate the advantages and challenges of bacteriophage and its components on biofilm removal, as well as potential usage of phage cocktail, combination therapy, and genetically modified phages in a clinical setting.},
}
@article {pmid35493738,
year = {2022},
author = {Sass, G and Marsh, JJ and Shrestha, P and Sabino, R and Stevens, DA},
title = {Synergy Between Pseudomonas aeruginosa Filtrates And Voriconazole Against Aspergillus fumigatus Biofilm Is Less for Mucoid Isolates From Persons With Cystic Fibrosis.},
journal = {Frontiers in cellular and infection microbiology},
volume = {12},
number = {},
pages = {817315},
pmid = {35493738},
issn = {2235-2988},
mesh = {Aspergillus fumigatus/metabolism ; Biofilms ; *Coinfection ; *Cystic Fibrosis/complications/microbiology ; Humans ; Pseudomonas aeruginosa/metabolism ; Voriconazole/pharmacology ; },
abstract = {Persons with cystic fibrosis (CF) frequently suffer from Pseudomonas aeruginosa and Aspergillus fumigatus co-infections. There is evidence that co-infections with these interacting pathogens cause airway inflammation and aggravate deterioration of lung function. We recently showed that P. aeruginosa laboratory isolates synergistically interact with the anti-fungal azole voriconazole (VCZ), inhibiting biofilm metabolism of several A. fumigatus laboratory strains. Interaction was usually mediated via pyoverdine, but also via pyocyanin or pyochelin. Here we used planktonic filtrates of 7 mucoid and 9 non-mucoid P. aeruginosa isolates from CF patients, as well as 8 isolates without CF origin, and found that all of these isolates interacted with VCZ synergistically at their IC50 as well as higher dilutions. CF mucoid isolates showed the weakest interactive effects. Four non-mucoid P. aeruginosa CF isolates produced no or very low levels of pyoverdine and did not reach an IC50 against forming A. fumigatus biofilm; interaction with VCZ still was synergistic. A VCZ-resistant A. fumigatus strain showed the same level of susceptibility for P. aeruginosa anti-fungal activity as a VCZ-susceptible reference strain. Filtrates of most Pseudomonas isolates were able to increase anti-fungal activity of VCZ on a susceptible A. fumigatus strain. This was also possible for the VCZ-resistant strain. In summary these data show that clinical P. aeruginosa isolates, at varying degrees, synergistically interact with VCZ, and that pyoverdine is not the only molecule responsible. These data also strengthen the idea that during co-infections of A. fumigatus and P. aeruginosa lower concentrations of VCZ might be sufficient to control fungal growth.},
}
@article {pmid35491280,
year = {2022},
author = {Taşkın Kafa, AH and Hasbek, M},
title = {Synergistic efficacy of meropenem, ciprofloxacin and colistin antibiotics against planktonic and biofilm forms of Myroides odoratimimus bacterial isolates.},
journal = {Indian journal of medical microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.ijmmb.2022.04.004},
pmid = {35491280},
issn = {1998-3646},
abstract = {PURPOSE: In this study, it was aimed to investigate the combined synergistic efficacy of colistin (CT), meropenem (MEM), and ciprofloxacin (CIP) antibiotics on planktonic and biofilm forms in Myroidesodoratimimus strains isolated from various clinical specimens.<br><br>METHODS: Antibiotic susceptibility was determined by the Kirby-Bauer disk diffusion method. In addition, minimum inhibitory concentrations (MIC) of CIP, MEM, and CT were studied using the standardized broth microdilution method. In vitro synergistic activity of antibiotics against M. odoratimimus planktonic bacteria strains was studied by the Micro Broth Checkerboard method. The microtiter plate (MtP) method was used to determine the effectiveness of antibiotics on M. odoratimimus biofilm formation.<br><br>RESULTS: A zone of inhibition was not observed against other antibiotics used except amikacin and linezolid in all strains. While CT/MEM and CT/CIP combinations have a synergistic effect on all strains, the combination CIP/MEM has an additive effect. According to the biofilm inhibition results, all three antibiotics inhibited biofilm formation. However, the efficacy of MEM (60.3-76.5%) and CIP (60.2-77.8%) was approximately two times higher than that of CT (25.4-34.5%). In addition, the effectiveness of combinations of antibiotics on biofilm formation was examined and the percentage of inhibition was 30.8% when CT was used alone, while the biofilm inhibition rates of CT/MEM and CT/CIP were 92.4% and 91.7%, respectively. MEM/CIP combination was inhibited biofilm formation by 75.7%.<br><br>CONCLUSIONS: This study is the first report showing the efficacy of CT, MEM and CIP antibiotics, which are frequently used in clinical practice, in combination on M. odoratimimus planktonic and biofilm forms. The findings of our study are particularly guiding for combined antibiotic treatment options in immunosuppressed patients admitted to an intensive care unit (ICU). The CT/MEM combination is currently used frequently. In addition, these results are important in terms of supporting in vitro that CT/CIP and MEM/CIP combinations can also be used as a treatment option in M. odoratimimus related infections.},
}
@article {pmid35489461,
year = {2022},
author = {Xia, Y and Lu, D and Qi, Y and Chen, H and Zhao, Y and Bai, Y and Zhu, L and Geng, N and Xu, C and Hua, E},
title = {Removal of nitrate from agricultural runoff in biochar electrode based biofilm reactor: Performance and enhancement mechanisms.},
journal = {Chemosphere},
volume = {301},
number = {},
pages = {134744},
doi = {10.1016/j.chemosphere.2022.134744},
pmid = {35489461},
issn = {1879-1298},
abstract = {A biochar electrode based biofilm reactor was developed for advanced removal of nitrate from agricultural runoff. The corn-straw (Zea mays L.) biochar formed at 500 °C has an adsorption capacity of NO3--N up to 2.659 mg g-1. After 45-day start-up phase, the removal efficiency of nitrate reached 93.4% when impressed current was 20 mA, hydraulic retention time was 12 h and chemical oxygen demand/total nitrogen (C/N) ratio was 0.56 without additional carbon source. In comparison, neither electrochemical reduction alone nor microbial denitrification alone could obtain the ideal nitrate removal efficiency. The results implied that bio-electrochemical reduction was the main way of nitrate removal in the biofilm electrode reactor (BER). The denitrification efficiency of 88.9% could still be obtained when C/N = 0. It is because biochar can significantly promote the utilization efficiency of cathode electrons by microorganisms. Thus, biochar is a promising electrode material, which provides a new idea for the optimization of BER.},
}
@article {pmid35487949,
year = {2022},
author = {Tsagkari, E and Connelly, S and Liu, Z and McBride, A and Sloan, WT},
title = {The role of shear dynamics in biofilm formation.},
journal = {NPJ biofilms and microbiomes},
volume = {8},
number = {1},
pages = {33},
pmid = {35487949},
issn = {2055-5008},
support = {EP/V030515/1//RCUK | Engineering and Physical Sciences Research Council (EPSRC)/ ; EP/P029329/1//RCUK | Engineering and Physical Sciences Research Council (EPSRC)/ ; EP/K038885/1//RCUK | Engineering and Physical Sciences Research Council (EPSRC)/ ; EP/V030515/1//RCUK | Engineering and Physical Sciences Research Council (EPSRC)/ ; EP/P029329/1//RCUK | Engineering and Physical Sciences Research Council (EPSRC)/ ; EP/K038885/1//RCUK | Engineering and Physical Sciences Research Council (EPSRC)/ ; EP/R008531/1//RCUK | Engineering and Physical Sciences Research Council (EPSRC)/ ; EP/T008415/1//RCUK | Engineering and Physical Sciences Research Council (EPSRC)/ ; EP/V030515/1//RCUK | Engineering and Physical Sciences Research Council (EPSRC)/ ; EP/P029329/1//RCUK | Engineering and Physical Sciences Research Council (EPSRC)/ ; EP/K038885/1//RCUK | Engineering and Physical Sciences Research Council (EPSRC)/ ; CiET//Royal Academy of Engineering/ ; },
mesh = {Bacteria ; *Biofilms ; *Drinking Water ; Stress, Mechanical ; },
abstract = {There is growing evidence that individual bacteria sense and respond to changes in mechanical loading. However, the subtle responses of multispecies biofilms to dynamic fluid shear stress are not well documented because experiments often fail to disentangle any beneficial effects of shear stress from those delivered by convective transport of vital nutrients. We observed the development of biofilms with lognormally distributed microcolony sizes in drinking water on the walls of flow channels underflow regimes of increasing complexity. First, where regular vortices induced oscillating wall shear and simultaneously enhanced mass transport, which produced the thickest most extensive biofilms. Second, where unsteady uniform flow imposed an oscillating wall shear, with no enhanced transport, and where the biomass and coverage were only 20% smaller. Finally, for uniform steady flows with constant wall shear where the extent, thickness, and density of the biofilms were on average 60% smaller. Thus, the dynamics of shear stress played a significant role in promoting biofilm development, over and above its magnitude or mass transfer effects, and therefore, mechanosensing may prevail in complex multispecies biofilms which could open up new ways of controlling biofilm structure.},
}
@article {pmid35487006,
year = {2022},
author = {Pan, T and Chen, H and Gao, X and Wu, Z and Ye, Y and Shen, Y},
title = {Engineering efficient artificial nanozyme based on chitosan grafted Fe-doped-carbon dots for bacteria biofilm eradication.},
journal = {Journal of hazardous materials},
volume = {435},
number = {},
pages = {128996},
doi = {10.1016/j.jhazmat.2022.128996},
pmid = {35487006},
issn = {1873-3336},
abstract = {Bacterial biofilms have evoked worldwide attention owing to their serious threats to public health, but how to effectively eliminate bacterial biofilms still remains great challenges. Here, we rationally designed a novel and vigorous chitosan grafted Fe-doped-carbon dots (CS@Fe/CDs) as an efficient artificial nanozyme to combat rigid bacterial biofilms through the selective activation of Fenton-like reaction-triggered peroxidase-like catalytic activity and the synergistic antibacterial activity of CS. On the one hand, the peroxidase-like catalytic activity made CS@Fe/CDs catalyze H2O2 for producing hydroxyl radicals (•OH), resulting in efficient cleavage of extracellular DNA (eDNA). On the other hand, CS was capable of binding with the negatively charged cell membrane through electrostatic interaction, changing the cell membrane permeability and causing cell death within bacterial biofilms. Based on their synergistic effects, the fragments of bacterial biofilm and exposed bacteria were persistently eradicated. Remarkably, CS@Fe/CDs-based nanozyme not only enabled the effective destroying of gram-positive Staphylococcus aureus (S. aureus) biofilms, but also completely eliminated gram-negative Pseudomonas aeruginosa (P. aeruginosa) biofilms, showing great potential as a promising anti-biofilm agent against bacteria biofilms. This proposed synergistic strategy for bacterial biofilm eradication might offer a powerful modality to manage of bacterial biofilm fouling in food safety and environmental protection.},
}
@article {pmid35486299,
year = {2022},
author = {Alviz-Gazitua, P and González, A and Lee, MR and Aranda, CP},
title = {Molecular Relationships in Biofilm Formation and the Biosynthesis of Exoproducts in Pseudoalteromonas spp.},
journal = {Marine biotechnology (New York, N.Y.)},
volume = {},
number = {},
pages = {},
pmid = {35486299},
issn = {1436-2236},
support = {ID20I10127//Fondo de Fomento al Desarrollo Científico y Tecnológico/ ; },
abstract = {Most members of the Pseudoalteromonas genus have been isolated from living surfaces as members of epiphytic and epizooic microbiomes on marine macroorganisms. Commonly Pseudoalteromonas isolates are reported as a source of bioactive exoproducts, i.e., secondary metabolites, such as exopolymeric substances and extracellular enzymes. The experimental conditions for the production of these agents are commonly associated with sessile metabolic states such as biofilms or liquid cultures in the stationary growth phase. Despite this, the molecular mechanisms that connect biofilm formation and the biosynthesis of exoproducts in Pseudoalteromonas isolates have rarely been mentioned in the literature. This review compiles empirical evidence about exoproduct biosynthesis conditions and molecular mechanisms that regulate sessile metabolic states in Pseudoalteromonas species, to provide a comprehensive perspective on the regulatory convergences that generate the recurrent coexistence of both phenomena in this bacterial genus. This synthesis aims to provide perspectives on the extent of this phenomenon for the optimization of bioprospection studies and biotechnology processes based on these bacteria.},
}
@article {pmid35483462,
year = {2022},
author = {Zhou, L and Lai, Y and Zeng, R and Zhao, B and Jian, Y and Ou, P and Zhang, W and Ng, HY and Zhuang, WQ},
title = {Core carbon fixation pathways associated with cake layer development in an anoxic-oxic biofilm-membrane bioreactor treating textile wastewater.},
journal = {The Science of the total environment},
volume = {835},
number = {},
pages = {155483},
doi = {10.1016/j.scitotenv.2022.155483},
pmid = {35483462},
issn = {1879-1026},
abstract = {Microbial carbon fixation pathways have not yet been adequately understood for their role in membrane case layer formation processes. Carbon fixation bacteria can play critical roles in either causing or enhancing cake layer formation in some autotrophic-prone anoxic conditions, such as sulfur-cycling conditions. Understanding the microbes capable of carbon fixation can potentially guide the design of membrane biofouling mitigation strategies in scientific ways. Thus, we used meta-omics methods to query carbon fixation pathways in the cake layers of a full-scale anoxic-oxic biofilm-MBR system treating textile wastewater in this study. Based on the wastewater constituents and other properties, such as anoxic conditions, sulfide-reducing and sulfur-oxidizing bacteria could co-exist in the membrane unit. In addition, low-light radiation conditions could also happen to the membrane unit. However, we could not quantify the light intensity or total energy input accurately because the whole experimental setup was a full-scale system. Potentially complete carbon fixation pathways in the cake layer included the Calvin-Benson-Bassham cycle, Wood-Ljungdahl pathway, and the 3-hydroxypropionate bicycle. We discovered that using aeration could effectively inhibit carbon fixation, which resulted in mitigating membrane cake layer development. However, the aeration resulted in the 3-hydroxypropionate bicycle pathway, presumably used by aerobic sulfur-oxidizing prokaryotes, to become a more abundant carbon fixation pathway in the cake layer under aerobic conditions.},
}
@article {pmid35483311,
year = {2022},
author = {Law, SKK and Tan, HS},
title = {The role of quorum sensing, biofilm formation, and iron acquisition as key virulence mechanisms in Acinetobacter baumannii and the corresponding anti-virulence strategies.},
journal = {Microbiological research},
volume = {260},
number = {},
pages = {127032},
doi = {10.1016/j.micres.2022.127032},
pmid = {35483311},
issn = {1618-0623},
mesh = {*Acinetobacter Infections/drug therapy/microbiology ; *Acinetobacter baumannii ; Anti-Bacterial Agents/pharmacology ; Biofilms ; Drug Resistance, Multiple, Bacterial ; Humans ; Iron ; Quorum Sensing ; Virulence ; Virulence Factors ; },
abstract = {Acinetobacter baumannii is a nosocomial pathogen responsible for several serious infections, including pneumonia, sepsis, and meningitis. The propensity of this bacterium to rapidly acquire antibiotic resistance leads to the emergence and spread of multidrug-resistant A. baumannii strains. As a result, antibiotics are becoming less effective in treating infections caused by this pathogen. In recent years, increasing efforts have focused on developing therapeutic compounds that could reduce the ability of A. baumannii to establish infection by inhibiting the virulence factors and pathogenesis of this pathogen without interfering with the bacterial viability. These alternative therapeutic options may impose milder selective pressure, reducing the likelihood of anti-virulence resistance development. To develop novel anti-virulence therapies, an in-depth understanding of the bacterial virulence mechanisms is crucial to identifying potential drug targets. This review summarises the latest discoveries about the virulence of A. baumannii, focusing on quorum sensing, biofilm formation, and iron acquisition, along with the corresponding anti-virulence strategies. This article also elaborates on the practical challenges involved in developing anti-virulence drugs. Therapeutic agents that target bacterial virulence factors may play a crucial role in controlling infection in the human host. Combining anti-virulence agents with existing antibiotics could enhance the therapeutic potential of these antibiotics against A. baumannii. Although anti-virulence therapy has been envisioned as an attractive alternative to overcome antimicrobial resistance, additional research on the possibility of developing resistance against anti-virulence drugs is encouraged to evaluate the sustainability of these strategies. Moreover, future studies on the efficacy of anti-virulence therapy against a diverse panel of clinical isolates and in polymicrobial A. baumannii infections are required to provide more valuable information about its clinical application.},
}
@article {pmid35481976,
year = {2021},
author = {Kiran, GS and Priyadharshini, S and Anitha, K and Gnanamani, E and Selvin, J},
title = {Correction: Characterization of an exopolysaccharide from probiont Enterobacter faecalis MSI12 and its effect on the disruption of Candida albicans biofilm.},
journal = {RSC advances},
volume = {11},
number = {33},
pages = {20003-20005},
doi = {10.1039/d1ra90123k},
pmid = {35481976},
issn = {2046-2069},
abstract = {[This corrects the article DOI: 10.1039/C5RA10302A.].},
}
@article {pmid35481543,
year = {2022},
author = {Gupta, P and Kulshrestha, A},
title = {Polymicrobial interaction in biofilm: mechanistic Insights.},
journal = {Pathogens and disease},
volume = {},
number = {},
pages = {},
doi = {10.1093/femspd/ftac010},
pmid = {35481543},
issn = {2049-632X},
abstract = {Polymicrobial biofilm formation during multi-species infection is a serious threat growing worldwide. According to CDC, the microbial biofilm infection covers more than 65% of total infection. In many diseases, their natural habitat does not have one causative agent because most of the species exist in co-aggregation (such as CF, OM, Dental Caries) leading to polymicrobial biofilm. Polymicrobial biofilm is a big problem in bacterio-fungal and inter-species bacterial diseases developed during chronic illness and created a major health burden globally. This review focused on various aspects of polymicrobial biofilms such as why they are forming polymicrobial biofilm arrangements, the significance of studying these biofilms, the interaction between causative microbes. Also, we reviewed how these interactions and polymicrobial formations make the biofilm more recalcitrant towards the treatment. Understanding the mechanistic process behind these biofilm formations gives an insight into specific molecules, proteins responsible for their polymicrobial nature are likely to be very helpful in anti-microbial researches.},
}
@article {pmid35480673,
year = {2021},
author = {Hou, Y and Liu, M and Tan, X and Hou, S and Yang, P},
title = {Study on COD and nitrogen removal efficiency of domestic sewage by hybrid carrier biofilm reactor.},
journal = {RSC advances},
volume = {11},
number = {44},
pages = {27322-27332},
pmid = {35480673},
issn = {2046-2069},
abstract = {A moving bed biofilm reactor (MBBR) is a kind of commonly used biological sewage treatment process. A carrier, the core of MBBR, could directly affect the treatment efficiency of MBBR. In this experiment, a hybrid carrier composed of an MBBR carrier and fluidized bed porous carrier was innovatively utilized to treat low-concentration simulated domestic sewage through an MBBR reactor to investigate the effects of different hydraulic retention times (HRT) and different carrier dose ratios on the reactor performance. The results indicated that when the volume ratio of the carrier dosage was 5% : 20% when the reactor HRT was 5 h, the removal rates of ammonia nitrogen, total nitrogen (TN) and chemical oxygen demand (CODCr) were optimal, which were 96.5%, 60.9% and 91.5%, respectively. The ammonia nitrogen, total nitrogen and CODCr concentrations of the effluent were 1.04 mg L-1, 12.20 mg L-1 and 29.02 mg L-1, respectively. Furthermore, the total biomass concentration in the hybrid carrier biofilm reactor (HCBR) was 3790.35 mg L-1, which also reached the highest value. As the experiment progressed, the concentrations of protein, polysaccharide and soluble microbial products (SMP) were reduced to 7.68 mg L-1, 11.10 mg L-1 and 18.08 mg L-1, respectively. This was basically consistent with the results of the three-dimensional fluorescence spectrum. The results showed that the combined-carrier biofilm reactor could reduce the volumetric filling rate, improving the removal capability of organic matter and the denitrification efficiency. This study provided technical support for the composite carrier biofilm wastewater treatment technology, and also had a good prospect of application.},
}
@article {pmid35480051,
year = {2022},
author = {Zhang, L and Shen, Y and Qiu, L and Yu, F and Hu, X and Wang, M and Sun, Y and Pan, Y and Zhang, K},
title = {The suppression effect of SCH-79797 on Streptococcus mutans biofilm formation.},
journal = {Journal of oral microbiology},
volume = {14},
number = {1},
pages = {2061113},
pmid = {35480051},
issn = {2000-2297},
abstract = {Background: SCH-79797 was recently shown to be a broad-spectrum antibacterial agent with a dual-bactericidal mechanism. However, its anti-biofilm effect remains unknown.<br><br>Purpose: To investigate the effect of SCH-79797 on the biofilm formation of the cariogenic Streptococcus mutans.<br><br>Methods and Results: Crystal violet staining, colony forming units count and MTT assays (for cell metabolic activity) revealed that S. mutans biofilm formation was significantly suppressed. In addition, virulence factors, including extracellular polysaccharides (investigated by bacterial/exopolysaccharide staining and the anthrone method) and acid production (investigated by lactic acid and supernatant pH detection) were also inhibited significantly. Moreover, the biofilm inhibitory effect of SCH-79797 was mediated through its repression of bacterial growth and not by a bactericidal effect, which was verified by growth curve and bacterial live/ dead staining, respectively. Quantitative real-time PCR results disclosed that SCH-79797 affected bacterial acid production and tolerance, polysaccharide synthesis and remodeling, biofilm formation and quorum sensing-related gene expression. In addition, SCH-79797 showed good biocompatibility as determined by cytotoxicity assays.<br><br>Conclusion: SCH-79797 had an anti-biofilm effect and showed application prospects in the control of dental caries.},
}
@article {pmid35479755,
year = {2022},
author = {Ghosh, S and Nag, M and Lahiri, D and Sarkar, T and Pati, S and Kari, ZA and Nirmal, NP and Edinur, HA and Ray, RR},
title = {Engineered Biofilm: Innovative Nextgen Strategy for Quality Enhancement of Fermented Foods.},
journal = {Frontiers in nutrition},
volume = {9},
number = {},
pages = {808630},
pmid = {35479755},
issn = {2296-861X},
abstract = {Microbial communities within fermented food (beers, wines, distillates, meats, fishes, cheeses, breads) products remain within biofilm and are embedded in a complex extracellular polymeric matrix that provides favorable growth conditions to the indwelling species. Biofilm acts as the best ecological niche for the residing microbes by providing food ingredients that interact with the fermenting microorganisms' metabolites to boost their growth. This leads to the alterations in the biochemical and nutritional quality of the fermented food ingredients compared to the initial ingredients in terms of antioxidants, peptides, organoleptic and probiotic properties, and antimicrobial activity. Microbes within the biofilm have altered genetic expression that may lead to novel biochemical pathways influencing their chemical and organoleptic properties related to consumer acceptability. Although microbial biofilms have always been linked to pathogenicity owing to its enhanced antimicrobial resistance, biofilm could be favorable for the production of amino acids like l-proline and L-threonine by engineered bacteria. The unique characteristics of many traditional fermented foods are attributed by the biofilm formed by lactic acid bacteria and yeast and often, multispecies biofilm can be successfully used for repeated-batch fermentation. The present review will shed light on current research related to the role of biofilm in the fermentation process with special reference to the recent applications of NGS/WGS/omics for the improved biofilm forming ability of the genetically engineered and biotechnologically modified microorganisms to bring about the amelioration of the quality of fermented food.},
}
@article {pmid35479228,
year = {2021},
author = {Cortés, I and Cordisco, E and Kaufman, TS and Sortino, MA and Svetaz, LA and Bracca, ABJ},
title = {First total synthesis of chromanone A, preparation of related compounds and evaluation of their antifungal activity against Candida albicans, a biofilm forming agent.},
journal = {RSC advances},
volume = {11},
number = {32},
pages = {19587-19597},
pmid = {35479228},
issn = {2046-2069},
abstract = {A straightforward and convenient approach for the first total syntheses of chromanone A and a related 7-OMe substituted natural product is reported. These unique C-3 substituted 2-hydroxymethyl chromones were recently isolated as fungal metabolites. Chromanone A was synthesized in 25.3% overall yield from the readily available pyrocatechol, whereas the second natural product was prepared in 39.7% global yield. A small library of chromones, including both natural products and some of their synthetic heterocyclic precursors, was evaluated against Candida albicans ATCC 10231, a biofilm forming agent. It was found that 8-methoxy-3-methyl-4-oxo-4H-chromene-2-carbaldehyde, a partially oxidized form of chromanone A, exhibited a minimum inhibitory concentration of 7.8 μg mL-1 and significantly inhibited the yeast's virulence factors, including the adherence to buccal epithelial cells and the secretion of phospholipases, as well as the formation of germ tubes and the generation of the hyphal pseudomycelium. In addition, despite the heterocycle exhibiting non-significant inhibition of the formation of the Candida biofilm, it completely inhibited the growth of C. albicans in preformed biofilms at 62.5 μg mL-1.},
}
@article {pmid35479152,
year = {2021},
author = {O'Reilly, C and Blasco, S and Parekh, B and Collins, H and Cooke, G and Gunnlaugsson, T and Byrne, JP},
title = {Ruthenium-centred btp glycoclusters as inhibitors for Pseudomonas aeruginosa biofilm formation.},
journal = {RSC advances},
volume = {11},
number = {27},
pages = {16318-16325},
pmid = {35479152},
issn = {2046-2069},
abstract = {Carbohydrate-decorated clusters (glycoclusters) centred on a Ru(ii) ion were synthesised and tested for their activity against Pseudomonas aeruginosa biofilm formation. These clusters were designed by conjugating a range of carbohydrate motifs (galactose, glucose, mannose and lactose, as well as galactose with a triethylene glycol spacer) to a btp (2,6-bis(1,2,3-triazol-4-yl)pyridine) scaffold. This scaffold, which possesses a C 2 symmetry, is an excellent ligand for d-metal ions, and thus the formation of the Ru(ii)-centred glycoclusters 7 and 8Gal was achieved from 5 and 6Gal; each possessing four deprotected carbohydrates. Glycocluster 8Gal, which has a flexible spacer between the btp and galactose moieties, showed significant inhibition of P. aeruginosa bacterial biofilm formation. By contrast, glycocluster 7, which lacked the flexible linker, didn't show significant antimicrobial effects and neither does the ligand 6Gal alone. These results are proposed to arise from carbohydrate-lectin interactions with LecA, which are possible for the flexible metal-centred multivalent glycocluster. Metal-centred glycoclusters present a structurally versatile class of antimicrobial agent for P. aeruginosa, of which this is, to the best of our knowledge, the first example.},
}
@article {pmid35477339,
year = {2022},
author = {Ceccarelli, F and Saccucci, M and Natalucci, F and Olivieri, G and Bruni, E and Iacono, R and Colasanti, T and Di Carlo, G and Alessandri, C and Uccelletti, D and Russo, P and Pilloni, A and Conti, F and Polimeni, A},
title = {Porphyromonas gingivalis amount in the tongue biofilm is associated with erosive arthritis in systemic lupus erythematosus.},
journal = {Lupus},
volume = {},
number = {},
pages = {9612033221098528},
doi = {10.1177/09612033221098528},
pmid = {35477339},
issn = {1477-0962},
abstract = {BACKGROUND: Several data have demonstrated the occurrence of erosive arthritis in Systemic Lupus Erythematosus (SLE) patients. However, a few studies have focused on the pathogenic mechanisms involved in this feature. The implication of oral pathogens has been proved in Rheumatoid Arthritis: in particular, Porphyromonas gingivalis (Pg), by inducing citrullination, could trigger autoimmune response. Here, we evaluated amount of Pg on the tongue in a cohort of SLE patients with arthritis, focusing on the association with the erosive phenotype.<br><br>METHODS: SLE patients with arthritis were enrolled. DAS28 was applied to assess activity. Erosive damage was evaluated by ultrasound at level of MCP (metacarpophalangeal) and PIP (proximal interphalangeals) joints. All subjects underwent a tongue cytologic swab in order to quantify the amount of Pg (real-time PCR). The bacterium expression was obtained from the ratio between the patient's DNA amount and that obtained from healthy subjects.<br><br>RESULTS: 33 patients were enrolled (M/F 3/30; median age 47 years, IQR 17; median disease duration 216 months, IQR 180): 12 of them (36.4%) showed erosive damage, significantly associated with ACPA positivity (p = 0.03) and higher values of DAS28 (p = 0.01). A mean ratio of 19.7 ± 31.1 was found for Pg amount. Therefore, we used Pg mean values as threshold, identifying two groups of patients, namely, highPg and lowPg. Erosive damage was significantly more frequent in highPg patients in comparison with lowPg (60.0% vs 26.0%, p = 0.001). Furthermore, highPg patients showed higher prevalence of skin manifestations, serositis, and neurological involvement (p = 0.005, p = 0.03, p = 0.0001, respectively).<br><br>CONCLUSION: The possible contribution of oral microbiota in SLE erosive arthritis was here evaluated for the first time, finding a significant association between erosive damage and higher expression of Pg at tongue level.},
}
@article {pmid35477070,
year = {2022},
author = {de Oliveira Pinto Ribeiro, A and Carolina da Silva, A and de Camargo Ribeiro, F and Sabino, CF and Junqueira, JC and de Paula Ramos, L and Dias de Oliveira, L and Bastos Campos, TM and Marques de Melo Marinho, R},
title = {Biofilm formation and cell viability on monolithic zirconia with silver-doped sodalime glass.},
journal = {Journal of the mechanical behavior of biomedical materials},
volume = {131},
number = {},
pages = {105222},
doi = {10.1016/j.jmbbm.2022.105222},
pmid = {35477070},
issn = {1878-0180},
abstract = {The present study evaluated the effect of glass application with and without silver-doped soda-lime glass on roughness, biofilm formation, cell viability and flexural strength of a zirconia. Samples of 3-YTZP (3 mol% yttria stabilized tetragonal zirconia polycrystals) were divided into: polished (P); glaze (G); glass infiltration (INF); 4% silver-doped soda-lime glass (Ag4); glass infiltration + 4% silver-doped soda-lime glass (INF-Ag4); 5% silver-doped soda-lime glass (Ag5); glass infiltration + 5% silver-doped soda-lime glass (INF-Ag5). Samples were submitted to the following analyses: roughness (Ra); free surface energy (FSE); colony-forming units count (log CFU/mL); scanning electron microscopy (SEM); cytotoxicity (MTT assay) and flexural strength. Ag5 had greater roughness and FSE, but less biofilm adherence. In the CFU, silver-doped soda-lime glass groups inhibited the growth of Candida albicans, while the Ag5 inhibited Streptococcus mutans and none of the groups was effective against Streptococcus sanguinis. In the qualitative evaluation, lower number of colonies in the Ag5 grew up, compared to the control groups (P; G and INF) for both C. albicans and S. mutans. Regarding the MTT assay, the Ag4, INF-Ag4 and INF-Ag5 obtained percentage of cell viability greater than 50%. Ag5 showed lower flexural strength when compared to the control groups, while the application of glass infiltration increased the flexural strength by formation of a graded region between zirconia-glass. In conclusion, Ag5 had the greatest antimicrobial effect, Ag4 and INF-Ag4 were the less cytotoxic and the INF was the most resistant to fracture. Therefore, INF-Ag4 conciliates the best performance in terms of antimicrobial and mechanical properties for a 3-YTZP.},
}
@article {pmid35476392,
year = {2022},
author = {Dang, J and Zhu, M and Dong, F and Zhong, R and Liu, Z and Fang, J and Zhang, J and Pan, J},
title = {Ultrasound-Activated Nanodroplet Disruption of the Enterococcus faecalis Biofilm in Dental Root Canal.},
journal = {ACS applied bio materials},
volume = {5},
number = {5},
pages = {2135-2142},
doi = {10.1021/acsabm.1c01031},
pmid = {35476392},
issn = {2576-6422},
mesh = {Anti-Bacterial Agents/pharmacology ; Biofilms ; Chlorhexidine/pharmacology ; Dental Pulp Cavity ; *Enterococcus faecalis ; Humans ; *Root Canal Irrigants/pharmacology ; },
abstract = {Conventional methods used to control bacterial biofilm infection in root canals have poor efficacy, causing repeated and chronic infections, which pose a great challenge to clinical treatment. Microbubbles, due to their small size and ultrasound (US)-enhanced cavitation effects, have attracted considerable clinical attention. They possess the potential for therapeutic application in restricted spaces. We address the above problem with a strategy for the restricted space of root canals. Herein, phase-change nanodroplets (P-NDs) exposed to US are combined with common antibacterial drugs to disrupt a 7 day Enterococcus faecalis biofilm in an in vitro human tooth model. Specifically, the preparation of P-NDs is based on secondary cavitation. Their average particle size is ∼144 nm, and the stability is favorable. The clearance effect for the biofilm is notable (the disruption rate of P-NDs + US is 63.1%, P < 0.01), while the effect of an antibacterial in conjunction with 2% chlorhexidine (Chx) is significant (the antibiofilm rate of P-NDs@2% Chx + US is 96.2%, P < 0.001). Furthermore, biocompatibility testing on human periodontal ligament fibroblasts demonstrated that P-NDs are safe. In summary, the strategy that we have proposed is suitable for the removal of biofilms in root canals. Notably, it also has great potential for application in the treatment of bacterial infections in restricted spaces.},
}
@article {pmid35475640,
year = {2022},
author = {Trampari, E and Zhang, C and Gotts, K and Savva, GM and Bavro, VN and Webber, M},
title = {Cefotaxime Exposure Selects Mutations within the CA-Domain of envZ Which Promote Antibiotic Resistance but Repress Biofilm Formation in Salmonella.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0214521},
doi = {10.1128/spectrum.02145-21},
pmid = {35475640},
issn = {2165-0497},
support = {MR/L015080/1/MRC_/Medical Research Council/United Kingdom ; },
abstract = {Cephalosporins are important beta lactam antibiotics, but resistance can be mediated by various mechanisms including production of beta lactamase enzymes, changes in membrane permeability or active efflux. We used an evolution model to study how Salmonella adapts to subinhibitory concentrations of cefotaxime in planktonic and biofilm conditions and characterized the mechanisms underpinning this adaptation. We found that Salmonella rapidly adapts to subinhibitory concentrations of cefotaxime via selection of multiple mutations within the CA-domain region of EnvZ. We showed that changes in this domain affect the ATPase activity of the enzyme and in turn impact OmpC, OmpF porin expression and hence membrane permeability leading to increased tolerance to cefotaxime and low-level resistance to different classes of antibiotics. Adaptation to cefotaxime through EnvZ also resulted in a significant cost to biofilm formation due to downregulation of curli. We assessed the role of the mutations identified on the activity of EnvZ by genetic characterization, biochemistry and in silico analysis and confirmed that they are responsible for the observed phenotypes. We observed that sublethal cefotaxime exposure selected for heterogeneity in populations with only a subpopulation carrying mutations within EnvZ and being resistant to cefotaxime. Population structure and composition dynamically changed depending on the presence of the selection pressure, once selected, resistant subpopulations were maintained even in extended passage without drug. IMPORTANCE Understanding mechanisms of antibiotic resistance is crucial to guide how best to use antibiotics to minimize emergence of resistance. We used a laboratory evolution system to study how Salmonella responds to cefotaxime in both planktonic and biofilm conditions. In both contexts, we observed rapid selection of mutants within a single hot spot within envZ. The mutations selected altered EnvZ which in turn triggers changes in porin production at the outer membrane. Emergence of mutations within this region was repeatedly observed in parallel lineages in different conditions. We used a combination of genetics, biochemistry, phenotyping and structural analysis to understand the mechanisms. This data show that the changes we observe provide resistance to cefotaxime but come at a cost to biofilm formation and the fitness of mutants changes greatly depending on the presence or absence of a selective drug. Studying how resistance emerges can inform selective outcomes in the real world.},
}
@article {pmid35474246,
year = {2022},
author = {Sun, M and Chan, KF and Zhang, Z and Wang, L and Wang, Q and Yang, S and Chan, SM and Chiu, PWY and Sung, JJY and Zhang, L},
title = {Magnetic Microswarm and Fluoroscopy-Guided Platform for Biofilm Eradication in Biliary Stents.},
journal = {Advanced materials (Deerfield Beach, Fla.)},
volume = {},
number = {},
pages = {e2201888},
doi = {10.1002/adma.202201888},
pmid = {35474246},
issn = {1521-4095},
abstract = {Biofilm eradication from medical implants is of fundamental importance, and the treatment of biofilm-associated pathogen infections on inaccessible biliary stents remains challenging. Magnetically driven microrobots with controlled motility, accessibility to the tiny lumen, and swarm enhancement effects can physically disrupt the deleterious biostructures while not developing drug resistance. We design magnetic urchin-like capsule robots (MUCRs) loaded with magnetic liquid metal droplets (MLMDs, antibacterial agents) using natural sunflower pollen, and explore the therapeutic effect of swarming MUCR@MLMDs for eradicating complex mixtures of bacterial biofilm within biliary stents collected from patients. The external magnetic field triggers the emergence of the microswarm and induces MLMDs to transform their shape into spheroids and rods with sharp edges. The inherent natural microspikes of MUCRs and the obtained sharp edges of MLMDs actively rupture the dense biological matrix and multiple species of embedded bacterial cells by exerting mechanical force, finally achieving synergistic biofilm eradication. The microswarm is precisely and rapidly deployed into the biliary stent via endoscopy in 10 minutes. Notably, fluoroscopy imaging is used to track and navigate the locomotion of microswarm in biliary stents in real-time. The microswarm has great potential for treating bacterial biofilm infections associated with medical implants. This article is protected by copyright. All rights reserved.},
}
@article {pmid35473968,
year = {2022},
author = {Sun, Y and Ma, Y and Guan, H and Liang, H and Zhao, X and Wang, D},
title = {Adhesion mechanism and biofilm formation of Escherichia coli O157:H7 in infected cucumber (Cucumis sativus L.).},
journal = {Food microbiology},
volume = {105},
number = {},
pages = {103885},
doi = {10.1016/j.fm.2021.103885},
pmid = {35473968},
issn = {1095-9998},
mesh = {Biofilms ; *Cucumis sativus/metabolism ; *Escherichia coli O157 ; *Escherichia coli Proteins/genetics ; Fruit/metabolism ; },
abstract = {Cucumber is usually eaten as a raw vegetable and easily contaminated by pathogenic microorganisms; the contamination process includes colonization, proliferation, and biofilm formation. In this study, plate counting was used to determine the stage of E. coli O157:H7 colonization/proliferation in cucumber epidermis and fruit. Expression of E. coli genes associated with adhesion, movement and oxidative stress response during colonization and proliferation in cucumber was evaluated with fluorescence real-time quantitative PCR. Scanning electron microscopy imaging was used to observe biofilm formation over time in different cucumber tissues at 4 °C and 25 °C. During colonization (at 0-45 and 0-30 min in epidermis and fruit, respectively), escV, fliC, espA, escN, espF, espG, espZ, nleA, tir, and ycbR genes were upregulated. The escC was downregulated, while map and espH expression did not vary. During proliferation (after 45 and 30 min in epidermis and fruit, respectively), fliC was downregulated, whereas the outer membrane protein intimin gene and oxidative stress genes rpoS and sodB were upregulated. During storage, 25 °C was more favorable for biofilm formation than 4 °C. The ability of biofilm formation on the vascular system was the strongest, and the biofilm on epidermis sloughed off earlier than that on other tissues. Clarifying the process of E. coli O157:H7 contaminating cucumbers provided useful information for the development of prevention and control methods of fresh-cut cucumber.},
}
@article {pmid35470982,
year = {2022},
author = {Secker, TJ and Harling, CC and Hand, C and Voegeli, D and Keevil, CW and Leighton, TG},
title = {A proof-of-concept study of the removal of early and late phase biofilm from skin wound models using a liquid acoustic stream.},
journal = {International wound journal},
volume = {},
number = {},
pages = {},
doi = {10.1111/iwj.13818},
pmid = {35470982},
issn = {1742-481X},
support = {EP/M027260/1//NAMRIP Pump priming supported by EPSRC/ ; },
abstract = {Chronic wounds fail to progress through the normal stages of healing, with the largest remediable cause of chronicity being presence of a multi-species biofilm. Removal of biofilm from the wound environment is central to wound care. A device for mechanically removing biofilms from wounds has been devised. The removal is caused by small-scale liquid currents and shear, generated by acoustically activated microscopic air bubbles. These bubbles and acoustic waves are delivered onto the wound by a gentle liquid stream, allowing cleaning in situ and removal of debris in the run-off liquid. We have investigated if this liquid acoustic wound stream (LAWS) can remove bacterial biofilm from soft biological wound models and studied the effect of LAWS on the cellular tissues of the substrate. LAWS will efficiently remove early Pseudomonas aeruginosa biofilm from an artificial wound in a pig's trotter, 24 hours-mature biofilm of P. aeruginosa from a pre-wounded human full thickness skin model (EpiDerm FT), and 3-day mature biofilm of P. aeruginosa or Staphylococcus aureus from a porcine skin explant. Histological examinations of uninfected EpiDerm models that had been treated by LAWS and then stained with Haematoxylin and Eosin, demonstrated no damage to the human tissue, and wound diameter was smaller in the treated skin models compared with untreated samples. Immunofluorescence staining for cytokeratin 14 showed that keratinocytes had migrated further across the wound in the uninfected samples treated by LAWS. We discuss the implications for wound healing and propose further laboratory and clinical studies to demonstrate the removal of biofilm from patients with chronic leg ulcers and the impact on healing.},
}
@article {pmid35470896,
year = {2022},
author = {Zhang, YM and Jiang, YH and Li, HW and Li, XZ and Zhang, QL},
title = {Purification and characterization of Lactobacillus plantarum-derived bacteriocin with activity against Staphylococcus argenteus planktonic cells and biofilm.},
journal = {Journal of food science},
volume = {},
number = {},
pages = {},
doi = {10.1111/1750-3841.16148},
pmid = {35470896},
issn = {1750-3841},
support = {202101BE070001-046//Applied Basic Research Foundation of Yunnan Province/ ; 2021-SF-A4//Major Science and Technology Projects of Qinghai Province/ ; 2019-ZJ-967Q//Natural Science Foundation of Qinghai Province/ ; },
abstract = {Bacteriocins inhibit various foodborne bacteria in planktonic and biofilm forms. However, bacteriocins with antibacterial and antibiofilm activity against Staphylococcus argenteus, a pathogen that can cause food poisoning, are still poorly known. Here, the novel bacteriocin LSB1 derived from Lactobacillus plantarum CGMCC 1.12934 was purified and characterized extensively. LSB1 had a molecular weight of 1425.78 Da and an amino acid sequence of YIFVTGGVVSSLGK. Moreover, LSB1 exhibited excellent stability under heat and acid-base stress and presented sensitivity to pepsin and proteinase K. LSB1 exhibited an extensive antimicrobial spectrum against both Gram-positive and Gram-negative bacteria. Minimum inhibitory concentration of LSB1 against S. argenteus_70917 was 10.36 µg/ml, which was lower than that of most of the previously found bacteriocins against Staphylococcus strains. Furthermore, LSB1 significantly inhibited S. argenteus_70917 planktonic cells (p < 0.01) and decreased their viability. Scanning electron microscopy analysis revealed that cell membrane permeability of S. argenteus_70917 upon exposure to LSB1 showed leakage of cytoplasmic contents and rupture, leading to cell death. In addition, biofilm formation ability of S. argenteus_70917 was significantly (p < 0.01) impaired by LSB1, with the percent inhibition of 35% at 10 µg/ml and 80% at 20 µg/ml. Overall, this study indicates that LSB1 can be considered a potential antibacterial agent in the control of S. argenteus in both planktonic and biofilm states. PRACTICAL APPLICATION: Foodborne pathogenic bacteria, such as Staphylococcus argenteus, and their biofilms represent potential risks for food safety. In recent years, customers' demand for "natural" products has increased food control. This study describes the novel bacteriocin LSB1 produced by the lactic acid bacterium species Lactobacillus plantarum. LSB1 showed strong antibacterial and antibiofilm activity against S. argenteus as well as thermal and acid-alkaline stability. Furthermore, the mechanisms of action of LSB1 on S. argenteus were preliminarily explored. These results indicate that LSB1 might be potentially used as an effective and natural food preservative.},
}
@article {pmid35470434,
year = {2022},
author = {Borges, MMB and Dijkstra, RJB and de Andrade, FB and Duarte, MAH and Versluis, M and van der Sluis, LWM and Petridis, X},
title = {The response of dual-species bacterial biofilm to 2% and 5% NaOCl mixed with etidronic acid: A laboratory real-time evaluation using optical coherence tomography.},
journal = {International endodontic journal},
volume = {},
number = {},
pages = {},
doi = {10.1111/iej.13754},
pmid = {35470434},
issn = {1365-2591},
support = {88887.371170/2019-00//Capes scholarship/ ; },
abstract = {AIM: The addition of etidronic acid (HEDP) to sodium hypochlorite (NaOCl) could increase the antibiofilm potency of the irrigant, whilst maintaining the benefits of continuous chelation. Studies conducted so far have shown that mixing HEDP with NaOCl solutions of relatively low concentration does not compromise the antibiofilm efficacy of the irrigant. However, the working lifespan of NaOCl may decrease resulting in a reduction of its antibiofilm efficacy over time (efficiency). In this regard, continuous irrigant replenishment needs to be examined. This study investigated the response of a dual-species biofilm when challenged with 2% and 5% NaOCl mixed with HEDP for a prolonged timespan and under steady laminar flow.<br><br>METHODOLOGY: Dual-species biofilms comprised of Streptococcus oralis J22 and Actinomyces naeslundii T14V-J1 were grown on human dentine discs in a constant depth film fermenter (CDFF) for 96 h. Biofilms were treated with 2% and 5% NaOCl, alone or mixed with HEDP. Irrigants were applied under steady laminar flow for 8 min. Biofilm response was evaluated by means of optical coherence tomography (OCT). Biofilm removal, biofilm disruption, rate of biofilm loss and disruption as well as bubble formation were assessed. One-way anova, Wilcoxon's signed-rank test and Kruskal-Wallis H test were performed for statistical analysis of the data. The level of significance was set at a ≤.05.<br><br>RESULTS: Increasing NaOCl concentration resulted in increased biofilm removal and disruption, higher rate of biofilm loss and disruption and increased bubble formation. Mixing HEDP with NaOCl caused a delay in the antibiofilm action of the latter, without compromising its antibiofilm efficacy.<br><br>CONCLUSIONS: NaOCl concentration dictates the biofilm response irrespective of the presence of HEDP. The addition of HEDP resulted in a delay in the antibiofilm action of NaOCl. This delay affects the efficiency, but not the efficacy of the irrigant over time.},
}
@article {pmid35469882,
year = {2022},
author = {Vincent, AES and Chaudhary, A and Kelly, JJ and Hoellein, TJ},
title = {Biofilm assemblage and activity on plastic in urban streams at a continental scale: Site characteristics are more important than substrate type.},
journal = {The Science of the total environment},
volume = {835},
number = {},
pages = {155398},
doi = {10.1016/j.scitotenv.2022.155398},
pmid = {35469882},
issn = {1879-1026},
abstract = {The fate of plastics in rivers is a key component of the global plastic cycle. Plastics entering freshwater ecosystems are colonized by microbial biofilms, and microbe-plastic interactions can influence ecosystem processes and plastic fate. While literature examining the role of geographic region on plastic biofilms is quickly expanding, research which covers large (i.e., continental) spatial scales and includes freshwater ecosystems is warranted. In addition, most research focuses on bacterial communities, while biofilm eukaryotes are less commonly studied. We assessed biofilm metabolism and community structure on plastic (foamed polystyrene and polyvinyl chloride; PVC) and natural substrates (unglazed ceramic tile) in urban streams spanning a nested geographic gradient in the continental United States. We measured biofilm biomass, community respiration, and chlorophyll a, in addition to assessing marker gene-based community diversity of bacterial, fungal, and algal assemblages. Results demonstrated some substrate-specific trends in biofilm characteristics, including higher biofilm biomass on polystyrene across sites, and lower diversity of bacterial assemblages on both types of plastic litter versus tile. However, there were no differences among substrates for chlorophyll, respiration, and the abundance and diversity of algal and fungal assemblages. Thus, we concluded that the primary driver of biofilm metabolism and community composition were site characteristics, rather than substrate type. Additional studies are needed to quantify which site-specific characteristics drive biofilm dynamics on plastic litter in streams (e.g., water chemistry, light, seasonality, hydrology). These results add to the growing literature on the biofilm 'plastisphere' in aquatic ecosystems, demonstrating that the factors which control the assembly and activity of biofilm communities on plastic substrates (including bacteria, algal, and fungal assemblages together) in urban streams are similar to those driving biofilm dynamics on natural substrates.},
}
@article {pmid35469529,
year = {2022},
author = {Anju, VT and Busi, S and Kumar, S and Suchiang, K and Kumavath, R and Ranganathan, S and Ampasala, DR and Dyavaiah, M},
title = {Alantolactone modulates the production of quorum sensing mediated virulence factors and biofilm formation in Pseudomonas aeruginosa.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-17},
doi = {10.1080/08927014.2022.2064747},
pmid = {35469529},
issn = {1029-2454},
abstract = {Pseudomonas aeruginosa is an opportunistic pathogen in immunocompromised patients and accounts for mortality worldwide. Quorum sensing (QS) and QS mediated biofilm formation of P. aeruginosa increase the severity of infection in the host. New and effective therapeutics are in high demand to eliminate Pseudomonas infections. The current study investigated the quorum quenching and biofilm inhibition properties of alantolactone (ATL) against P. aeruginosa PAO1. The production of key virulence factors and biofilm components were affected in bacteria when treated with sub-MIC of ATL and further validated by qRT-PCR studies. The anti-infective potential of ATL was corroborated in an in vivo model with improved survival of infected Caenorhabditis elegans and reduced bacterial colonization. In silico studies suggested the molecular interactions of ATL to QS proteins as stable. Finally, ATL was explored in the present study to inhibit QS pathways and holds the potential to develop into an effective anti-infective agent against P. aeruginosa.},
}
@article {pmid35468355,
year = {2022},
author = {Santore, MM},
title = {Interplay of physico-chemical and mechanical bacteria-surface interactions with transport processes controls early biofilm growth: A review.},
journal = {Advances in colloid and interface science},
volume = {304},
number = {},
pages = {102665},
doi = {10.1016/j.cis.2022.102665},
pmid = {35468355},
issn = {1873-3727},
abstract = {Biofilms initiate when bacteria encounter and are retained on surfaces. The surface orchestrates biofilm growth through direct physico-chemical and mechanical interactions with different structures on bacterial cells and, in turn, through its influence on cell-cell interactions. Individual cells respond directly to a surface through mechanical or chemical means, initiating "surface sensing" pathways that regulate gene expression, for instance producing extra cellular matrix or altering phenotypes. The surface can also physically direct the evolving colony morphology as cells divide and grow. In either case, the physico-chemistry of the surface influences cells and cell communities through mechanisms that involve additional factors. For instance the numbers of cells arriving on a surface from solution relative to the generation of new cells by division depends on adhesion and transport kinetics, affecting early colony density and composition. Separately, the forces experienced by adhering cells depend on hydrodynamics, gravity, and the relative stiffnesses and viscoelasticity of the cells and substrate materials, affecting mechanosensing pathways. Physical chemistry and surface functionality, along with interfacial mechanics also influence cell-surface friction and control colony morphology, in particular 2D and 3D shape. This review focuses on the current understanding of the mechanisms in which physico-chemical interactions, deriving from surface functionality, impact individual cells and cell community behavior through their coupling with other interfacial processes.},
}
@article {pmid35467829,
year = {2022},
author = {Mudenur, C and Boruah, P and Kumar, A and Katiyar, V},
title = {Prodigiosin-Loaded Poly(lactic acid) to Combat the Biofilm-Associated Infections.},
journal = {ACS applied bio materials},
volume = {5},
number = {5},
pages = {2143-2151},
doi = {10.1021/acsabm.1c01187},
pmid = {35467829},
issn = {2576-6422},
mesh = {Biofilms ; *Polyesters/chemistry ; *Prodigiosin/pharmacology ; Staphylococcus aureus ; },
abstract = {Poly(lactic acid) (PLA) is an emerging biobased implant material. Despite its biocompatibility and the aseptic procedures followed during orthopedic surgery, bacterial infection remains an obstacle to implementing PLA-based implants. To tackle this issue, prodigiosin-incorporated PLA has been developed, which possesses improved hydrophobicity with a contact angle of 111 ± 1.5°. The degradation temperature of the prodigiosin is 215 °C, which is more than the melting temperature of PLA, which supports the processability and sterilization of the PLA-based implants without any toxic gases. Further, prodigiosin improves the transparency of PLA and acts as a nucleation site. The spherulite density increases three times compared to that of neat PLA. The inherent methoxy group of prodigiosin is an active site responsible for the inhibition of bacterial attack and biofilm formation. The in vitro study on biofilm formation shows excellent inhibition activity against implant-associated pathogens such as Klebsiella aerogenes and Staphylococcus aureus.},
}
@article {pmid35467419,
year = {2022},
author = {Klementiev, AD and Jin, Z and Whiteley, M},
title = {Erratum for Klementiev et al., "Micron Scale Spatial Measurement of the O2 Gradient Surrounding a Bacterial Biofilm in Real Time".},
journal = {mBio},
volume = {},
number = {},
pages = {e0080322},
doi = {10.1128/mbio.00803-22},
pmid = {35467419},
issn = {2150-7511},
}
@article {pmid35467317,
year = {2022},
author = {Sharma, RP and Raut, SD and Jadhav, VV and Mulani, RM and Kadam, AS and Mane, RS},
title = {Assessment of antibacterial and anti-biofilm effects of zinc ferrite nanoparticles against Klebsiella pneumoniae.},
journal = {Folia microbiologica},
volume = {},
number = {},
pages = {},
pmid = {35467317},
issn = {1874-9356},
abstract = {In response to the emergence of drug resistance and limited therapeutic options, researchers are in action to look for more effective and sustainable antimicrobial practices. Over few years, novel nanoparticles are proving to be potent and promising for effectively dealing with ever- evolving microbial pathogens and diseases. In the present investigation, antibacterial and anti-biofilm efficiencies of zinc ferrite nanoparticles (ZnFe2O4 NPs) are explored against opportunistic pathogens Klebsiella pneumoniae (K. pneumoniae). Results of the present study demonstrate that the ZnFe2O4 NPs endow an excellent antibacterial efficiency with a maximum zone of inhibition i.e.16 mm. The reactive oxygen species (ROS)-induced bacterial damage is caused by the ZnFe2O4 NPs. Subsequently, intracellular cytoplasmic leakage of sugar and protein confirms their ability to disturb the membrane integrity of bacteria. This study also demonstrates the prominent efficiency of ZnFe2O4 NPs in an anti-biofilm study by inhibiting biofilm formation up to 81.76% and reducing mature biofilm up to 56.22% at 75 μg/mL the minimum inhibitory concentration value. Therapeutic possibilities of the ZnFe2O4 NPs in antimicrobial applications are discussed which are helpful to overcome the challenges associated with biofilm infectivity.},
}
@article {pmid35466520,
year = {2022},
author = {Gautam, A and Lear, G and Lewis, GD},
title = {Time after time: detecting annual patterns in stream bacterial biofilm communities.},
journal = {Environmental microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/1462-2920.16017},
pmid = {35466520},
issn = {1462-2920},
support = {//Centre for Biodiversity and Biosecurity, the University of Auckland/ ; //Auckland Council/ ; },
abstract = {To quantify the major environmental drivers of stream bacterial population dynamics, we modelled temporal differences in stream bacterial communities to quantify community shifts, including those relating to cyclical seasonal variation and more sporadic bloom events. We applied Illumina MiSeq 16S rRNA bacterial gene sequencing of 892 stream biofilm samples, collected monthly for 36-months from six streams. The streams were located a maximum of 118 km apart and drained three different catchment types (forest, urban and rural land uses). We identified repeatable seasonal patterns among bacterial taxa, allowing their separation into three ecological groupings, those following linear, bloom/trough and repeated, seasonal trends. Various physicochemical parameters (light, water and air temperature, pH, dissolved oxygen, nutrients) were linked to temporal community changes. Our models indicate that bloom events and seasonal episodes modify biofilm bacterial populations, suggesting that distinct microbial taxa thrive during these events including non-cyanobacterial community members. These models could aid in determining how temporal environmental changes affect community assembly and guide the selection of appropriate statistical models to capture future community responses to environmental change.},
}
@article {pmid35464993,
year = {2022},
author = {Liu, S and Chen, L and Wang, L and Zhou, B and Ye, D and Zheng, X and Lin, Y and Zeng, W and Zhou, T and Ye, J},
title = {Cluster Differences in Antibiotic Resistance, Biofilm Formation, Mobility, and Virulence of Clinical Enterobacter cloacae Complex.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {814831},
pmid = {35464993},
issn = {1664-302X},
abstract = {Due to the lack of research on the characteristics of different clusters of Enterobacter cloacae complex (ECC), this study aimed to characterize and explore the differences among species of the ECC. An analysis based on hsp60 showed that Enterobacter hormaechei was predominant in ECC. Interestingly, the antibiotic resistance rates of clusters were different, among which E. hormaechei subsp. steigerwaltii (cluster VIII) and Enterobacter cloacae IX (cluster IX) possessed high resistant rates to ciprofloxacin and levofloxacin, but cluster II (Enterobacter kobei) had low resistant rates. Cluster II exhibited a strong biofilm formation ability. Different motility and protease production ability were shown for distinct clusters. A PCR analysis showed that clusters I, III, VI, VIII, and IX carried more virulence genes, while cluster II had fewer. Clusters I, VIII, and IX with high pathogenicity were evaluated using the Galleria mellonella infection model. Thus, the characteristics of resistance, biofilm-forming ability, mobility, and virulence differed among the clusters. The strains were divided into 12 subgroups based on hsp60. The main clusters of ECC clinical strains were I, II, III, VI, VIII, and IX, among which IX, VIII, and I were predominant with high resistance and pathogenicity, and cluster II (E. kobei) was a special taxon with a strong biofilm formation ability under nutrient deficiency, but was associated with low resistance, virulence, and pathogenicity. Hence, clinical classification methods to identify ECC subgroups are an urgent requirement to guide the treatment of clinical infections.},
}
@article {pmid35464992,
year = {2022},
author = {Pouget, C and Dunyach-Remy, C and Bernardi, T and Provot, C and Tasse, J and Sotto, A and Lavigne, JP},
title = {A Relevant Wound-Like in vitro Media to Study Bacterial Cooperation and Biofilm in Chronic Wounds.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {705479},
pmid = {35464992},
issn = {1664-302X},
abstract = {Biofilm on the skin surface of chronic wounds is an important factor in the pathology, inhibiting wound healing. The polymicrobial nature of these infected wounds and bacterial interactions inside this pathogenic biofilm are the keys for understanding chronic infection. The aim of our work was to develop an innovative in vitro medium that closely mimics the chronic wound emphasizing the microbiological, cellular, and inflammatory environment of chronic wounds but also focusing on the pH found at the wound level. This new medium, called chronic wound medium (CWM), will thus facilitate the study of pathogenic biofilm organization. Clinical Staphylococcus aureus and Pseudomonas aeruginosa strains coisolated from diabetic foot infection were collected and cultivated in this new medium for 24 h in monoculture and coculture. Bacterial growth (growth curves), presence of small colony variant (SCV), biofilm formation (BioFilm Ring Test® assay, biofilm biomass quantification), and virulence (survival curve in a Caenorhabditis elegans model) were evaluated. After 24 h in the in vitro conditions, we observed that P. aeruginosa growth was not affected, compared with a control bacterial medium, whereas for S. aureus, the stationary phase was reduced by two logs. Interestingly, S. aureus growth increased when cocultured with P. aeruginosa in CWM. In coculture with P. aeruginosa, SCV forms of S. aureus were detected. Biofilm studies showed that bacteria, alone and in combination, formed biofilm faster (as soon as 3 h) than the bacteria exposed in a control medium (as soon as 5 h). The virulence of all strains decreased in the nematode model when cultivated in our new in vitro medium. Taken together, our data confirmed the impact of the chronic wound environment on biofilm formation and bacteria virulence. They indicated that P. aeruginosa and S. aureus cooperated in coinfected wounds. Therefore, this in vitro model provides a new tool for bacterial cooperation investigation and polymicrobial biofilm formation.},
}
@article {pmid35464966,
year = {2022},
author = {Lv, J and Zhu, J and Wang, T and Xie, X and Wang, T and Zhu, Z and Chen, L and Zhong, F and Du, H},
title = {The Role of the Two-Component QseBC Signaling System in Biofilm Formation and Virulence of Hypervirulent Klebsiella pneumoniae ATCC43816.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {817494},
pmid = {35464966},
issn = {1664-302X},
abstract = {Hypervirulent Klebsiella pneumoniae (hvKP) is an evolving infectious pathogen associated with high mortality. The convergence of hypervirulence and multidrug resistance further challenges the clinical treatment options for K. pneumoniae infections. The QseBC two-component system (TCS) is a component of quorum-sensing regulatory cascade and functions as a global regulator of biofilm growth, bacterial motility, and virulence in Escherichia coli. However, the functional mechanisms of QseBC in hvKP have not been reported, and we aim to examine the role of QseBC in regulating virulence in hvKP strain ATCC43816. The CRISPR-Cas9 system was used to construct qseB, qseC, and qseBC knockout in ATCC43816. No significant alterations in the growth and antibiotic susceptibility were detected between wild-type and mutants. The deletion of qseC led to an increase of biofilm formation, resistance to serum killing, and high mortality in the G. mellonella model. RNAseq differential gene expression analysis exhibited that gene-associated biofilm formation (glgC, glgP, glgA, gcvA, bcsA, ydaM, paaF, ptsG), bacterial type VI secretion system (virB4, virB6, virB10, vgrG, hcp), and biosynthesis of siderophore (entC, entD, entE) were significantly upregulated in comparison with the wild-type control. In addition, qseB, ygiW (encode OB-family protein), and AraC family transcriptional regulator IT767_23090 genes showed highest expressions in the absence of QseC, which might be related to increased virulence. The study provided new insights into the functional importance of QseBC in regulating the virulence of hvKP.},
}
@article {pmid35464965,
year = {2022},
author = {Petrin, S and Mancin, M and Losasso, C and Deotto, S and Olsen, JE and Barco, L},
title = {Effect of pH and Salinity on the Ability of Salmonella Serotypes to Form Biofilm.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {821679},
pmid = {35464965},
issn = {1664-302X},
abstract = {Salmonella is a major cause of food-borne infections in Europe, and the majority of human infections are caused by only a few serotypes, among them are Salmonella enterica subsp. enterica serotype Enteritidis (hereafter Salmonella Enteritidis), Salmonella Typhimurium, and the monophasic variant of S. Typhimurium. The reason for this is not fully understood, but could include virulence factors as well as increased ability to transfer via the external environment. Formation of biofilm is considered an adaptation strategy used by bacteria to overcome environmental stresses. In order to assess the capability of different Salmonella serotypes to produce biofilm and establish whether this is affected by pH and salinity, 88 Salmonella isolates collected from animal, food, and human sources and belonging to 15 serotypes, including those most frequently responsible for human infections, were tested. Strains were grown in tryptic soy broth (TSB), TSB with 4% NaCl pH 4.5, TSB with 10% NaCl pH 4.5, TSB with 4% NaCl pH 7, or TSB with 10% NaCl pH 7, and biofilm production was assessed after 24 h at 37°C using crystal violet staining. A linear mixed effect model was applied to compare results from the different experimental conditions. Among the tested serotypes, S. Dublin showed the greatest ability to form biofilm even at pH 4.5, which inhibited biofilm production in the other tested serotypes. Salmonella Senftenberg and the monophasic variant of S. Typhimurium showed the highest biofilm production in TSB with 10% NaCl pH 7. In general, pH had a high influence on the ability to form biofilm, and most of the tested strains were not able to produce biofilm at pH 4.5. In contrast, salinity only had a limited influence on biofilm production. In general, serotypes causing the highest number of human infections showed a limited ability to produce biofilm in the tested conditions, indicating that biofilm formation is not a crucial factor in the success of these clones.},
}
@article {pmid35464913,
year = {2022},
author = {Mettler, MK and Parker, CW and Venkateswaran, K and Peyton, BM},
title = {Antimicrobial Coating Efficacy for Prevention of Pseudomonas aeruginosa Biofilm Growth on ISS Water System Materials.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {874236},
pmid = {35464913},
issn = {1664-302X},
abstract = {Biofilms can lead to biofouling, microbially induced corrosion, physical impediment and eventual loss in function of water systems, and other engineered systems. The remoteness and closed environment of the International Space Station (ISS) make it vulnerable to unchecked biofilm growth; thus, biofilm mitigation strategies are crucial for current ISS operation and future long duration and deep-space crewed missions. In this study, a space flown bacterial strain of Pseudomonas aeruginosa (PA14) was used as a model organism for its ability to form biofilms. Additionally, a novel antimicrobial coating's ability to reduce biofilm accumulation on stainless steel, Teflon, titanium, and Inconel (all used in the ISS water treatment and handling systems) was analyzed. Coated materials demonstrated reductions of P. aeruginosa biofilm across all materials when tested in a continuous flow system with tryptic soy broth medium. However, the coating lost efficacy in potato dextrose broth medium. These findings were corroborated via scanning electron microscopy. This study illustrates the fundamental importance of using multiple approaches to test antibiofilm strategies, as well as the specificity in which conditions such strategies can be implemented.},
}
@article {pmid35460772,
year = {2022},
author = {Wang, J and He, M and Li, Y and Ma, F and Zheng, P and Hu, B},
title = {Rapid enrichment of denitrifying methanotrophs in a series hollow-fiber membrane biofilm reactor.},
journal = {The Science of the total environment},
volume = {834},
number = {},
pages = {155375},
doi = {10.1016/j.scitotenv.2022.155375},
pmid = {35460772},
issn = {1879-1026},
abstract = {Denitrifying anaerobic methane oxidation (DAMO) process uses methane as electron donor to reduce nitrate/nitrite to dinitrogen, which is a potentially efficient, low-cost and clean biological nitrogen removal technology. However, slow microbial growth rate severely limits the application of this promising process. In this study, a series hollow-fiber membrane biofilm reactor (HfMBR) was operated for 90 days to achieve rapid enrichment of these denitrifying methanotrophs. Finally, the highest relative abundance of denitrifying methanotrophic archaea and bacteria (DAMO archaea and bacteria) reached 47.5% and 11.3%, respectively. And the average abundance of DAMO archaea and bacteria increased 92.9 and 136.6 times respectively during the 90-day enrichment. High growth rate of DAMO archaea with a doubling time of 11.6 days was achieved in the second HfMBR according to quantitative PCR results. The results implied that dissolved oxygen would inhibit the growth of DAMO archaea, but the series HfMBR could effectively counteract this unfavorable factor. This work provided theoretical guidance for the rapid enrichment of denitrifying methanotrophs and contributed to the application of methane-dependent denitrification process.},
}
@article {pmid35458369,
year = {2022},
author = {Alfuraydi, RT and Alminderej, FM and Mohamed, NA},
title = {Evaluation of Antimicrobial and Anti-Biofilm Formation Activities of Novel Poly(vinyl alcohol) Hydrogels Reinforced with Crosslinked Chitosan and Silver Nano-Particles.},
journal = {Polymers},
volume = {14},
number = {8},
pages = {},
pmid = {35458369},
issn = {2073-4360},
abstract = {Novel hydrogels were prepared by blending chitosan and poly(vinyl alcohol), PVA, then crosslinking the resulting blends using trimellitic anhydride isothiocyanate at a concentration based on chitosan content in the blends. The weight ratios of chitosan: PVA in the blends were 1:3, 1:1, and 3:1 to produce three hydrogels symbolized as H13, H11, and H31, respectively. For a comparison, H10 was also prepared by crosslinking pure chitosan with trimellitic anhydride isothiocyanate. For further modification, three H31/silver nanocomposites (AgNPs) were synthesized using three different concentrations of silver nitrate to obtain H31/AgNPs1%, H31/AgNPs3% and H31/AgNPs5%. The structures of the prepared samples were emphasized using various analytical techniques. PVA has no inhibition activity against the tested microbes and biofilms. The antimicrobial and anti-biofilm formation activities of the investigated samples was arranged as: H31/AgNPs5% ≥ H31/AgNPs3% > H31/AgNPs1% > H10 > H31 > H11 > H13 > chitosan. H31/AgNPs5% and H31/AgNPs3% were more potent than Vancomycin and Amphotericin B against most of the tested microbes. Interestingly, H31 and H31/AgNPs3% were safe on the normal human cells. Consequently, hydrogels resulting from crosslinked blends of chitosan and PVA loaded with AgNPs in the same structure have significantly reinforced the antimicrobial and inhibition activity against the biofilms of PVA.},
}
@article {pmid35457654,
year = {2022},
author = {Al-Bayati, M and Samarasinghe, S},
title = {Biofilm and Gene Expression Characteristics of the Carbapenem-Resistant Enterobacterales, Escherichia coli IMP, and Klebsiella pneumoniae NDM-1 Associated with Common Bacterial Infections.},
journal = {International journal of environmental research and public health},
volume = {19},
number = {8},
pages = {},
pmid = {35457654},
issn = {1660-4601},
support = {Ministry of Higher Education and Scientific Research Baghdad / Iraq and Mustansiriyah University (https://uomustansiriyah.edu.iq),//This work is supported by the funding received by the Ministry of Higher Education and Scientific Research Baghdad / Iraq and Mustansiriyah University (https://uomustansiriyah.edu.iq), for a PhD scholarship grant to MA under SS supervision/ ; },
mesh = {Anti-Bacterial Agents/pharmacology/therapeutic use ; Bacterial Proteins/genetics ; *Biofilms ; Carbapenems/pharmacology ; *Drug Resistance, Bacterial/genetics ; *Enterobacteriaceae Infections/drug therapy ; Escherichia coli/genetics ; *Escherichia coli Infections ; Gene Expression ; Humans ; *Klebsiella Infections/genetics ; Klebsiella pneumoniae/genetics ; Microbial Sensitivity Tests ; beta-Lactamases/genetics/metabolism ; },
abstract = {In light of the limited therapeutic options with Carbapenem-Resistant Enterobacterales (CRE) infections, understanding the bacterial risk factors, such as biofilm formation and related gene expression of CRE, is vital. This study investigates the biofilm formation and biofilm-related gene expression of two enteric Enterobacterales with major CR determinants Escherichia coli IMP and Klebsiella pneumoniae NDM-1, which were seen in high prevalence in most common bacterial infections over the past few years. To our knowledge, this is the first study that demonstrated the relationship between biofilm formation and the related gene expression, to understand the potential molecular mechanisms during the biofilm formation in CRE. Biofilms were quantified by tissue culture plate assay at the stages of the biofilm development: initial attachment (6 h), microcolony formation (12 h), maturation (24 h), and dispersion (48 h). In a dispersion, event bacteria detach without any mechanical means and colonise another area. To investigate the influence of different growth conditions on biofilm formation, biofilms were quantified under different growth conditions. In parallel, quantitative real-time PCR (qPCR) assessed the biofilm-related gene expression of a cluster of genes, including biofilm maturation, quorum sensing, stress survival, and antibiotic resistance. Structural changes during biofilm development were assessed via confocal laser scanning microscopy (CLSM). We observed that the biofilm formation of CRE is correlated with the biofilm development stages, with maximum biofilm observed at 24 h at the maturation stage. Our data also showed that biofilm growth, under the condition tested, is the major factor influencing the variability of biofilm gene expression quantification assays. qPCR analyses have demonstrated that the expression of biofilm-related genes is highly correlated with phenotypic biofilm development, and these findings can be further expanded to understand the variation in regulation of such genes in these significant CRE pathogens. Our study demonstrated that both CRE strains, E. coli IMP and K. pneumoniae NDM-1, are high biofilm formers, and genes involved in biofilm development are upregulated during biofilm growth. The characteristic of the increased biofilm formation with the upregulation of antibiotic-resistant and biofilm-related genes indicates the successful pathogenic role of biofilms of these selected CRE and is attributed to their multi-drug resistance ability and successful dissemination of CRE in common bacterial infections.},
}
@article {pmid35457494,
year = {2022},
author = {Haghighi, F and Andriasian, L and Tran, NC and Lux, R},
title = {Effect of Cigarette and E-Cigarette Smoke Condensates on Candida albicans Biofilm Formation and Gene Expression.},
journal = {International journal of environmental research and public health},
volume = {19},
number = {8},
pages = {},
pmid = {35457494},
issn = {1660-4601},
support = {T30FT0812//Tobacco-Related Disease Research Program (TRDRP)/ ; },
mesh = {Antifungal Agents/pharmacology ; Biofilms ; Candida albicans ; *Cigarette Smoking ; *Electronic Nicotine Delivery Systems ; Gene Expression ; Nicotine/pharmacology ; Tobacco ; *Tobacco Products ; },
abstract = {Smoking triggers environmental changes in the oral cavity and increases the risk of mucosal infections caused by Candida albicans such as oral candidiasis. While cigarette smoke has a significant impact on C. albicans, how e-cigarettes affect this oral pathogen is less clear. Here, we investigated the effect of cigarette and e-cigarette smoke condensates (CSC and ECSC) on C. albicans growth, biofilm formation, and gene expression. Whereas pure nicotine (N) at the minimum inhibitory concentration (MIC, 4 mg/mL) prevented C. albicans growth, enhanced biofilm formation was observed at 0.1 mg/mL. In contrast, at this nicotine sub-MIC (0.1 mg/mL) concentration, CSC and ECSC had no significant effect on C. albicans biofilm formation. Additionally, N, CSC, and ECSC increased the expression of HWP1 and SAP2 genes. The ECSC group exhibited elevated expression levels of the EAP1 and ALS3 genes, compared to the nicotine-free ECSC (-) control. Moreover, our in vitro study illustrated that the antifungal drugs, fluconazole and amphotericin B, alleviated the effect of nicotine on C. albicans gene expression. Overall, the results of the study indicated nicotine from different sources may affect the pathogenic characteristics of C. albicans, including hyphal growth, biofilm formation, and particularly the expression of virulence-related genes.},
}
@article {pmid35457206,
year = {2022},
author = {Scribani Rossi, C and Barrientos-Moreno, L and Paone, A and Cutruzzolà, F and Paiardini, A and Espinosa-Urgel, M and Rinaldo, S},
title = {Nutrient Sensing and Biofilm Modulation: The Example of L-arginine in Pseudomonas.},
journal = {International journal of molecular sciences},
volume = {23},
number = {8},
pages = {},
pmid = {35457206},
issn = {1422-0067},
support = {RM120172A7AD98EB to SR and AR12117A63EE6037 to CSR//Sapienza University of Rome/ ; PID2019-109372GB-I00//MCIN/AEI/10.13039/501100011033/ ; ERDF A way of making Europe//European Union/ ; Sensing arginine through the Venus Fly Trap domain to control c-di-GMP levels in Pseudomonas aeruginosa: molecular mechanism and metabolic effects of signal transduction.//Istituto Pasteur Italia - Fondazione Cenci Bolognetti/ ; },
mesh = {Arginine/metabolism/pharmacology ; Bacterial Proteins/metabolism ; Biofilms ; Carbon/metabolism/pharmacology ; *Cyclic GMP/metabolism ; Nitrogen/metabolism/pharmacology ; Nutrients ; Pseudomonas/metabolism ; *Pseudomonas aeruginosa/physiology ; },
abstract = {Bacterial biofilm represents a multicellular community embedded within an extracellular matrix attached to a surface. This lifestyle confers to bacterial cells protection against hostile environments, such as antibiotic treatment and host immune response in case of infections. The Pseudomonas genus is characterised by species producing strong biofilms difficult to be eradicated and by an extraordinary metabolic versatility which may support energy and carbon/nitrogen assimilation under multiple environmental conditions. Nutrient availability can be perceived by a Pseudomonas biofilm which, in turn, readapts its metabolism to finally tune its own formation and dispersion. A growing number of papers is now focusing on the mechanism of nutrient perception as a possible strategy to weaken the biofilm barrier by environmental cues. One of the most important nutrients is amino acid L-arginine, a crucial metabolite sustaining bacterial growth both as a carbon and a nitrogen source. Under low-oxygen conditions, L-arginine may also serve for ATP production, thus allowing bacteria to survive in anaerobic environments. L-arginine has been associated with biofilms, virulence, and antibiotic resistance. L-arginine is also a key precursor of regulatory molecules such as polyamines, whose involvement in biofilm homeostasis is reported. Given the biomedical and biotechnological relevance of biofilm control, the state of the art on the effects mediated by the L-arginine nutrient on biofilm modulation is presented, with a special focus on the Pseudomonas biofilm. Possible biotechnological and biomedical applications are also discussed.},
}
@article {pmid35457049,
year = {2022},
author = {Wang, S and Liu, XQ and Kang, OH and Kwon, DY},
title = {Combination of Sanguisorbigenin and Conventional Antibiotic Therapy for Methicillin-Resistant Staphylococcus aureus: Inhibition of Biofilm Formation and Alteration of Cell Membrane Permeability.},
journal = {International journal of molecular sciences},
volume = {23},
number = {8},
pages = {},
pmid = {35457049},
issn = {1422-0067},
support = {2022//Wonkwang University/ ; },
mesh = {Anti-Bacterial Agents/pharmacology ; Biofilms ; Cell Membrane Permeability ; *Methicillin-Resistant Staphylococcus aureus ; Microbial Sensitivity Tests ; },
abstract = {Methicillin-resistant Staphylococcus aureus (MRSA) infection is challenging to eradicate because of antibiotic resistance and biofilm formation. Novel antimicrobial agents and alternative therapies are urgently needed. This study aimed to evaluate the synergy of sanguisorbigenin (SGB) isolated from Sanguisorba officinalis L. with six conventional antibiotics to achieve broad-spectrum antibacterial action and prevent the development of resistance. A checkerboard dilution test and time-to-kill curve assay were used to determine the synergistic effect of SGB combined with antibiotics against MRSA. SGB showed significant synergy with antibiotics and reduced the minimum inhibitory concentration of antibiotics by 2-16-fold. Biofilm inhibition assay, quantitative RT-PCR, crystal violet absorption, and transmission electron microscopy were performed to evaluate the synergy mechanism. The results indicated that SGB could inhibit biofilm formation and alter cell membrane permeability in MRSA. In addition, SGB was found to exhibit quite low cytotoxicity and hemolysis. The discovery of the superiority of SGB suggests that SGB may be an antibiotic adjuvant for use in combination therapy and as a plant-derived antibacterial agent targeting biofilms.},
}
@article {pmid35456851,
year = {2022},
author = {Kruppa, O and Czermak, P},
title = {Screening for Biofilm-Stimulating Factors in the Freshwater Planctomycete Planctopirus limnophila to Improve Sessile Growth in a Chemically Defined Medium.},
journal = {Microorganisms},
volume = {10},
number = {4},
pages = {},
pmid = {35456851},
issn = {2076-2607},
support = {LOEWE ZIB//Hessen State Ministry of Higher Education, Research, and the Arts/ ; },
abstract = {Planctomycetes such as Planctopirus limnophila offer a promising source of bioactive molecules, particularly when they switch from planktonic to sessile growth, but little is known about the corresponding biosynthetic gene clusters and how they are activated. We therefore screened for factors that promote sessile growth and biofilm formation to enable the cultivation of P. limnophila in a fixed-bed reactor. We carried out screening in microtiter plates focusing on biofilm formation and changes in optical density in response to various C:N ratios, metal ions, and oxidative stress. We used MTT assays and crystal violet staining to quantify biofilm formation. Positive factors were then validated in a fixed-bed bioreactor. The initial screen showed that D1ASO medium supplemented with NH4Cl to achieve a C:N ratio of 5.7:1, as well as 50 µM FeSO4 or CuSO4, increased the biofilm formation relative to the control medium. Exposure to H2O2 did not affect cell viability but stimulated biofilm formation. However, the same results were not replicated in the fixed-bed bioreactor, probably reflecting conditions that are unique to this environment such as the controlled pH and more vigorous aeration. Although we were able to cultivate P. limnophila in a fixed-bed bioreactor using a chemically defined medium, the factors that stimulate biofilm formation and inhibit planktonic growth were only identified in microtiter plates and further evaluation is required to establish optimal growth conditions in the bioreactor system.},
}
@article {pmid35456825,
year = {2022},
author = {Thaarup, IC and Iversen, AKS and Lichtenberg, M and Bjarnsholt, T and Jakobsen, TH},
title = {Biofilm Survival Strategies in Chronic Wounds.},
journal = {Microorganisms},
volume = {10},
number = {4},
pages = {},
pmid = {35456825},
issn = {2076-2607},
abstract = {Bacterial biofilms residing in chronic wounds are thought to have numerous survival strategies, making them extremely difficult to eradicate and resulting in long-term infections. However, much of our knowledge regarding biofilm persistence stems from in vitro models and experiments performed in vivo in animal models. While the knowledge obtained from such experiments is highly valuable, its direct translation to the human clinical setting should be undertaken with caution. In this review, we highlight knowledge obtained from human clinical samples in different aspects of biofilm survival strategies. These strategies have been divided into segments of the following attributes: altered transcriptomic profiles, spatial distribution, the production of extracellular polymeric substances, an altered microenvironment, inter-and intra-species interactions, and heterogeneity in the bacterial population. While all these attributes are speculated to contribute to the enhanced persistence of biofilms in chronic wounds, only some of them have been demonstrated to exist in human wounds. Some of the attributes have been observed in other clinical diseases while others have only been observed in vitro. Here, we have strived to clarify the limitations of the current knowledge in regard to this specific topic, without ignoring important in vitro and in vivo observations.},
}
@article {pmid35456808,
year = {2022},
author = {Kay, W and Hunt, C and Nehring, L and Barnum, B and Ashton, N and Williams, D},
title = {Biofilm Growth on Simulated Fracture Fixation Plates Using a Customized CDC Biofilm Reactor for a Sheep Model of Biofilm-Related Infection.},
journal = {Microorganisms},
volume = {10},
number = {4},
pages = {},
pmid = {35456808},
issn = {2076-2607},
support = {W81XWH-20-1-0384//United States Department of Defense/ ; },
abstract = {Most animal models of infection utilize planktonic bacteria as initial inocula. However, this may not accurately mimic scenarios where bacteria in the biofilm phenotype contaminate a site at the point of injury. We developed a modified CDC biofilm reactor in which biofilms can be grown on the surface of simulated fracture fixation plates. Multiple reactor runs were performed and demonstrated that monomicrobial biofilms of a clinical strain of methicillin-resistant Staphylococcus aureus, S. aureus ATCC 6538, and Pseudomonas aeruginosa ATCC 27853 consistently developed on fixation plates. We also identified a method by which to successfully grow polymicrobial biofilms of S. aureus ATCC 6538 and P. aeruginosa ATCC 27853 on fixation plates. This customized reactor can be used to grow biofilms on simulated fracture fixation plates that can be inoculated in animal models of biofilm implant-related infection that, for example, mimic open fracture scenarios. The reactor provides a method for growing biofilms that can be used as initial inocula and potentially improve the testing and development of antibiofilm technologies.},
}
@article {pmid35456793,
year = {2022},
author = {Marin, LM and Xiao, Y and Cury, JA and Siqueira, WL},
title = {Engineered Salivary Peptides Reduce Enamel Demineralization Provoked by Cariogenic S. mutans Biofilm.},
journal = {Microorganisms},
volume = {10},
number = {4},
pages = {},
pmid = {35456793},
issn = {2076-2607},
support = {106657/CAPMC/CIHR/Canada ; 400347/CAPMC/CIHR/Canada ; 25116//Canada Foundation for Innovation/ ; 2014/27034-5//São Paulo Research Foundation/ ; 2017/02692-8//São Paulo Research Foundation/ ; },
abstract = {Engineering of the acquired enamel pellicle using salivary peptides has been shown to be a promising anticaries strategy. However, the mechanisms by which these peptides protect teeth against tooth decay are not fully understood. In this study, we evaluated the effect of the engineered salivary peptides DR9-DR9 and DR9-RR14 on enamel demineralization in two experimental conditions: (1) adsorbed onto the enamel surface forming the AEP, and (2) forming the AEP combined with their use to treat the biofilms 2×/day, using a validated cariogenic Streptococcus mutans in vitro biofilm model. Biofilms were grown for 144 h on enamel slabs and then collected to determine the bacterial viability (CFU/biofilm) and biofilm mass (mg protein/biofilm), and to extract cellular/extracellular proteins, which were characterized by mass spectrometry. The culture medium was changed 2×/day to fresh medium, and pH (indicator of biofilm acidogenicity) and calcium concentration (indicator of demineralization) was determined in used medium. DR9-RR14 peptide significantly reduced enamel demineralization (p < 0.0001) in both experimental conditions. However, this peptide did not have a significant effect on biofilm biomass (p > 0.05) nor did it modulate the expression of cellular and extracellular bacterial proteins involved in biofilm cariogenicity. These findings suggest that DR9-RR14 may control caries development mainly by a physicochemical mechanism.},
}
@article {pmid35456532,
year = {2022},
author = {de Lima, LF and Andrade-Pinheiro, JC and Freitas, MA and da Silva, AI and Fonseca, VJA and da Silva, TG and da Silva, JCP and de Lima, RH and Sales, DL and Neves, RP and de Brito, ES and Ribeiro, PRV and Canuto, KM and Coutinho, HDM and Siyadatpanah, A and Kim, B and Morais-Braga, MFB},
title = {Anti-Candida Properties of Gossypium hirsutum L.: Enhancement of Fungal Growth, Biofilm Production and Antifungal Resistance.},
journal = {Pharmaceutics},
volume = {14},
number = {4},
pages = {},
pmid = {35456532},
issn = {1999-4923},
abstract = {(1) Background: Candida is a genus of yeasts with notable pathogenicity and significant ability to develop antimicrobial resistance. Gossypium hirsutum L., a medicinal plant that is traditionally used due to its antimicrobial properties, has demonstrated significant antifungal activity. Therefore, this study investigated the chemical composition and anti-Candida effects of aqueous (AELG) and hydroethanolic (HELG) extracts obtained from the leaves of this plant. (2) Methods: The extracts were chemically characterized by UPLC-QTOF-MS/MS, and their anti-Candida activities were investigated by analyzing cell viability, biofilm production, morphological transition, and enhancement of antifungal resistance. (3) Results: The UPLC-QTOF-MS/MS analysis revealed the presence of twenty-one compounds in both AELG and HELG, highlighting the predominance of flavonoids. The combination of the extracts with fluconazole significantly reduced its IC50 values against Candida albicans INCQS 40006, Candida tropicalis INCQS 40042, and C. tropicalis URM 4262 strains, indicating enhanced antifungal activity. About biofilm production, significant inhibition was observed only for the AELG-treated C. tropicalis URM 4262 strain in comparison with the untreated control. Accordingly, this extract showed more significant inhibitory effects on the morphological transition of the INCQS 40006 and URM 4387 strains of C. albicans (4) Conclusions: Gossypium hirsutum L. presents promising antifungal effects, that may be potentially linked to the combined activity of chemical constituents identified in its extracts.},
}
@article {pmid35456146,
year = {2022},
author = {Donadu, MG and Ferrari, M and Mazzarello, V and Zanetti, S and Kushkevych, I and Rittmann, SKR and Stájer, A and Baráth, Z and Szabó, D and Urbán, E and Gajdács, M},
title = {No Correlation between Biofilm-Forming Capacity and Antibiotic Resistance in Environmental Staphylococcus spp.: In Vitro Results.},
journal = {Pathogens (Basel, Switzerland)},
volume = {11},
number = {4},
pages = {},
pmid = {35456146},
issn = {2076-0817},
abstract = {The production of biofilms is a critical factor in facilitating the survival of Staphylococcus spp. in vivo and in protecting against various environmental noxa. The possible relationship between the antibiotic-resistant phenotype and biofilm-forming capacity has raised considerable interest. The purpose of the study was to assess the interdependence between biofilm-forming capacity and the antibiotic-resistant phenotype in 299 Staphylococcus spp. (S. aureus n = 143, non-aureus staphylococci [NAS] n = 156) of environmental origin. Antimicrobial susceptibility testing and detection of methicillin resistance (MR) was performed. The capacity of isolates to produce biofilms was assessed using Congo red agar (CRA) plates and a crystal violet microtiter-plate-based (CV-MTP) method. MR was identified in 46.9% of S. aureus and 53.8% of NAS isolates (p > 0.05), with resistance to most commonly used drugs being significantly higher in MR isolates compared to methicillin-susceptible isolates. Resistance rates were highest for clindamycin (57.9%), erythromycin (52.2%) and trimethoprim-sulfamethoxazole (51.1%), while susceptibility was retained for most last-resort drugs. Based on the CRA plates, biofilm was produced by 30.8% of S. aureus and 44.9% of NAS (p = 0.014), while based on the CV-MTP method, 51.7% of S. aureus and 62.8% of NAS were identified as strong biofilm producers, respectively (mean OD570 values: S. aureus: 0.779±0.471 vs. NAS: 1.053±0.551; p < 0.001). No significant differences in biofilm formation were observed based on MR (susceptible: 0.824 ± 0.325 vs. resistant: 0.896 ± 0.367; p = 0.101). However, pronounced differences in biofilm formation were identified based on rifampicin susceptibility (S: 0.784 ± 0.281 vs. R: 1.239 ± 0.286; p = 0.011). The mechanistic understanding of the mechanisms Staphylococcus spp. use to withstand harsh environmental and in vivo conditions is crucial to appropriately address the therapy and eradication of these pathogens.},
}
@article {pmid35456063,
year = {2022},
author = {Sedarat, Z and Taylor-Robinson, AW},
title = {Biofilm Formation by Pathogenic Bacteria: Applying a Staphylococcus aureus Model to Appraise Potential Targets for Therapeutic Intervention.},
journal = {Pathogens (Basel, Switzerland)},
volume = {11},
number = {4},
pages = {},
pmid = {35456063},
issn = {2076-0817},
abstract = {Carried in the nasal passages by up to 30% of humans, Staphylococcus aureus is recognized to be a successful opportunistic pathogen. It is a frequent cause of infections of the upper respiratory tract, including sinusitis, and of the skin, typically abscesses, as well as of food poisoning and medical device contamination. The antimicrobial resistance of such, often chronic, health conditions is underpinned by the unique structure of bacterial biofilm, which is the focus of increasing research to try to overcome this serious public health challenge. Due to the protective barrier of an exopolysaccharide matrix, bacteria that are embedded within biofilm are highly resistant both to an infected individual's immune response and to any treating antibiotics. An in-depth appraisal of the stepwise progression of biofilm formation by S. aureus, used as a model infection for all cases of bacterial antibiotic resistance, has enhanced understanding of this complicated microscopic structure and served to highlight possible intervention targets for both patient cure and community infection control. While antibiotic therapy offers a practical means of treatment and prevention, the most favorable results are achieved in combination with other methods. This review provides an overview of S. aureus biofilm development, outlines the current range of anti-biofilm agents that are used against each stage and summarizes their relative merits.},
}
@article {pmid35455414,
year = {2022},
author = {Trognon, J and Vera, G and Rima, M and Stigliani, JL and Amielet, L and El Hage, S and Lajoie, B and Roques, C and El Garah, F},
title = {Investigation of Direct and Retro Chromone-2-Carboxamides Based Analogs of Pseudomonas aeruginosa Quorum Sensing Signal as New Anti-Biofilm Agents.},
journal = {Pharmaceuticals (Basel, Switzerland)},
volume = {15},
number = {4},
pages = {},
pmid = {35455414},
issn = {1424-8247},
support = {Pre-maturation 2020//Regional Council of Occitanie/ ; },
abstract = {Biofilm formation is considered a major cause of therapeutic failure because bacteria in biofilms have higher protection against antimicrobials. Thus, biofilm-related infections are extremely challenging to treat and pose major concerns for public health, along with huge economic impacts. Pseudomonas aeruginosa, in particular, is a "critical priority" pathogen, responsible for severe infections, especially in cystic fibrosis patients because of its capacity to form resistant biofilms. Therefore, new therapeutic approaches are needed to complete the pipeline of molecules offering new targets and modes of action. Biofilm formation is mainly controlled by Quorum Sensing (QS), a communication system based on signaling molecules. In the present study, we employed a molecular docking approach (Autodock Vina) to assess two series of chromones-based compounds as possible ligands for PqsR, a LuxR-type receptor. Most compounds showed good predicted affinities for PqsR, higher than the PQS native ligand. Encouraged by these docking results, we synthesized a library of 34 direct and 25 retro chromone carboxamides using two optimized routes from 2-chromone carboxylic acid as starting material for both series. We evaluated the synthesized carboxamides for their ability to inhibit the biofilm formation of P. aeruginosa in vitro. Overall, results showed several chromone 2-carboxamides of the retro series are potent inhibitors of the formation of P. aeruginosa biofilms (16/25 compound with % inhibition ≥ 50% at 50 μM), without cytotoxicity on Vero cells (IC50 > 1.0 mM). The 2,4-dinitro-N-(4-oxo-4H-chromen-2-yl) benzamide (6n) was the most promising antibiofilm compound, with potential for hit to lead optimization.},
}
@article {pmid35455029,
year = {2022},
author = {Catovic, C and Abbes, I and Barreau, M and Sauvage, C and Follet, J and Duclairoir-Poc, C and Groboillot, A and Leblanc, S and Svinareff, P and Chevalier, S and Feuilloley, MGJ},
title = {Cotton and Flax Textiles Leachables Impact Differently Cutaneous Staphylococcus aureus and Staphylococcus epidermidis Biofilm Formation and Cytotoxicity.},
journal = {Life (Basel, Switzerland)},
volume = {12},
number = {4},
pages = {},
pmid = {35455029},
issn = {2075-1729},
abstract = {Bacteria can bind on clothes, but the impacts of textiles leachables on cutaneous bacteria remain unknown. Here, we studied for the first time the effects of cotton and flax obtained through classical and soft ecological agriculture on the representatives S. aureus and S. epidermidis bacteria of the cutaneous microbiota. Crude flax showed an inhibitory potential on S. epidermidis bacterial lawns whereas cotton had no effect. Textile fiber leachables were produced in bacterial culture media, and these extracts were tested on S. aureus and S. epidermidis. Bacterial growth was not impacted, but investigation by the crystal violet technique and confocal microscopy showed that all extracts affected biofilm formation by the two staphylococci species. An influence of cotton and flax culture conditions was clearly observed. Flax extracts had strong inhibitory impacts and induced the formation of mushroom-like defense structures by S. aureus. Conversely, production of biosurfactant by bacteria and their surface properties were not modified. Resistance to antibiotics also remained unchanged. All textile extracts, and particularly soft organic flax, showed strong inhibitory effects on S. aureus and S. epidermidis cytotoxicity on HaCaT keratinocytes. Analysis of flax leachables showed the presence of benzyl alcohol that could partly explain the effects of flax extracts.},
}
@article {pmid35454508,
year = {2022},
author = {Zhao, N and Cai, R and Zhang, Y and Wang, X and Zhou, N},
title = {A pH-Gated Functionalized Hollow Mesoporous Silica Delivery System for Photodynamic Sterilization in Staphylococcus aureus Biofilm.},
journal = {Materials (Basel, Switzerland)},
volume = {15},
number = {8},
pages = {},
pmid = {35454508},
issn = {1996-1944},
support = {42177212 and 21877054//National Natural Science Foundation of China/ ; },
abstract = {Multidrug-resistant bacteria are increasing, particularly those embedded in microbial biofilm. These bacteria account for most microbial infections in humans. Traditional antibiotic treatment has low efficiency in sterilization of biofilm-associated pathogens, and thus the development of new approaches is highly desired. In this study, amino-modified hollow mesoporous silica nanoparticles (AHMSN) were synthesized and used as the carrier to load natural photosensitizer curcumin (Cur). Then glutaraldehyde (GA) and polyethyleneimine (PEI) were used to seal the porous structure of AHMSN by the Schiff base reaction, forming positively charged AHMSN@GA@PEI@Cur. The Cur delivery system can smoothly diffuse into the negatively charged biofilm of Staphylococcus aureus (S. aureus). Then Cur can be released to the biofilm after the pH-gated cleavage of the Schiff base bond in the slightly acidic environment of the biofilm. After the release of the photosensitizer, the biofilm was irradiated by the blue LED light at a wavelength of 450 nm and a power of 37.4 mV/cm2 for 5 min. Compared with the control group, the number of viable bacteria in the biofilm was reduced by 98.20%. Therefore, the constructed pH-gated photosensitizer delivery system can efficiently target biofilm-associated pathogens and be used for photodynamic sterilization, without the production of antibiotic resistance.},
}
@article {pmid35454375,
year = {2022},
author = {Grassi, R and Nardi, GM and Mazur, M and Di Giorgio, R and Ottolenghi, L and Guerra, F},
title = {The Dental-BIOfilm Detection TECHnique (D-BioTECH): A Proof of Concept of a Patient-Based Oral Hygiene.},
journal = {Medicina (Kaunas, Lithuania)},
volume = {58},
number = {4},
pages = {},
pmid = {35454375},
issn = {1648-9144},
mesh = {Biofilms ; Biotechnology ; *Health Status ; Humans ; *Oral Hygiene ; Treatment Outcome ; },
abstract = {To date, no strong long-term data have been reported about new innovative clinical protocols to manage oral hygiene. An improper management of oral hygiene may lead to an increase in dental implant failure, and to an increase in infective complications in prosthetic rehabilitation. Personalized techniques are strongly required in dentistry and dental hygiene. A customized and personalized approach to oral hygiene is crucial in ensuring not only effective treatment, but also a careful analysis of the general health status of the patient involved in the therapeutic process. D-BioTECH is an acronym for Dental BIOfilm Detection Technique: it is based on a tailored approach to patients, ensuring that the operator actively interacts with the patient and their specific needs, especially during the domiciliary therapy. D-BioTECH is an approach to preventive care: in D-BioTECH, both dental hygienists and dentists play a central role. The use of a personalized approach to oral hygiene is the first step towards increasing implant and prosthesis survival rate; moreover, personalized medicine is strategic for managing and preventing the biological complications associated with several dental risk factors.},
}
@article {pmid35453246,
year = {2022},
author = {Goda, RM and El-Baz, AM and Khalaf, EM and Alharbi, NK and Elkhooly, TA and Shohayeb, MM},
title = {Combating Bacterial Biofilm Formation in Urinary Catheter by Green Silver Nanoparticle.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {11},
number = {4},
pages = {},
pmid = {35453246},
issn = {2079-6382},
abstract = {Urinary catheters are commonly associated with urinary tract infections. This study aims to inhibit bacterial colonisation and biofilm of urinary tract catheters. Silicon catheter pieces were varnished with green silver nanoparticles (AgNPs) using Pistacia lentiscus mastic to prevent bacterial colonisation. Pomegranate rind extract was used to synthesize AgNPs. AgNPs were characterized by UV-Vis spectroscopy, X-ray crystallography, and transmission electron microscopy (TEM). Results obtained revealed that the size of most AgNPs ranged between 15-25 nm and they took crystallised metal and oxidised forms. The amounts of released silver ions from 1 cm pieces of catheters coated with AgNPs were estimated for five days and ranged between 10.82 and 4.8 µg. AgNPs coated catheters significantly inhibited the colonisation of catheters by antibiotic-resistant clinical Gram-positive (Staphylococcus epidermidis and Staphylococcus aureus) and Gram-negative (Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, and Pseudomonas aeruginosa) bacteria. AgNPs-varnish was more active against Gram-negative bacteria than Gram-positive bacteria. The significant inhibitory effect of coated catheters lasted for 72 h for both Gram-positive and Gram-negative bacteria. Varnishing catheters with AgNPs may help to prevent bacterial colonisation and infections.},
}
@article {pmid35453227,
year = {2022},
author = {Pandey, RP and Mukherjee, R and Chang, CM},
title = {Emerging Concern with Imminent Therapeutic Strategies for Treating Resistance in Biofilm.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {11},
number = {4},
pages = {},
pmid = {35453227},
issn = {2079-6382},
abstract = {Biofilm production by bacteria is presumed to be a survival strategy in natural environments. The production of biofilms is known to be influenced by a number of factors. This paper has precisely elaborated on the different factors that directly influence the formation of biofilm. Biofilm has serious consequences for human health, and a variety of infections linked to biofilm have emerged, rapidly increasing the statistics of antimicrobial resistance, which is a global threat. Additionally, to combat resistance in biofilm, various approaches have been developed. Surface modifications, physical removal, and the use of nanoparticles are the recent advances that have enabled drug discovery for treating various biofilm-associated infections. Progress in nanoparticle production has led to the development of a variety of biofilm-fighting strategies. We focus on the present and future therapeutic options that target the critical structural and functional characteristics of microbial biofilms, as well as drug tolerance mechanisms, such as the extracellular matrix, in this review.},
}
@article {pmid35451837,
year = {2022},
author = {Ernst, S and Volkov, AN and Stark, M and Hölscher, L and Steinert, K and Fetzner, S and Hennecke, U and Drees, SL},
title = {Azetidomonamide and Diazetidomonapyridone Metabolites Control Biofilm Formation and Pigment Synthesis in Pseudomonas aeruginosa.},
journal = {Journal of the American Chemical Society},
volume = {144},
number = {17},
pages = {7676-7685},
doi = {10.1021/jacs.1c13653},
pmid = {35451837},
issn = {1520-5126},
mesh = {*Azetidines ; Bacterial Proteins/genetics/metabolism ; Biofilms ; *Pseudomonas aeruginosa/metabolism ; Quorum Sensing/genetics ; Virulence Factors ; },
abstract = {Synthesis of azetidine-derived natural products by the opportunistic pathogen Pseudomonas aeruginosa is controlled by quorum sensing, a process involving the production and sensing of diffusible signal molecules that is decisive for virulence regulation. In this study, we engineered P. aeruginosa for the titratable expression of the biosynthetic aze gene cluster, which allowed the purification and identification of two new products, azetidomonamide C and diazetidomonapyridone. Diazetidomonapyridone was shown to have a highly unusual structure with two azetidine rings and an open-chain diimide moiety. Expression of aze genes strongly increased biofilm formation and production of phenazine and alkyl quinolone virulence factors. Further physiological studies revealed that all effects were mainly mediated by azetidomonamide A and diazetidomonapyridone, whereas azetidomonamides B and C had little or no phenotypic impact. The P450 monooxygenase AzeF which catalyzes a challenging, stereoselective hydroxylation of the azetidine ring converting azetidomonamide C into azetidomonamide A is therefore crucial for biological activity. Based on our findings, we propose this group of metabolites to constitute a new class of diffusible regulatory molecules with community-related effects in P. aeruginosa.},
}
@article {pmid35450484,
year = {2022},
author = {Babeer, A and Oh, MJ and Ren, Z and Liu, Y and Marques, F and Poly, A and Karabucak, B and Steager, E and Koo, H},
title = {Microrobotics for Precision Biofilm Diagnostics and Treatment.},
journal = {Journal of dental research},
volume = {},
number = {},
pages = {220345221087149},
doi = {10.1177/00220345221087149},
pmid = {35450484},
issn = {1544-0591},
abstract = {Advances in small-scale robotics and nanotechnology are providing previously unimagined opportunities for new diagnostic and therapeutic approaches with high precision, control, and efficiency. We designed microrobots for tetherless biofilm treatment and retrieval using iron oxide nanoparticles (NPs) with dual catalytic-magnetic functionality as building blocks. We show 2 distinct microrobotic platforms. The first system is formed from NPs that assemble into aggregated microswarms under magnetic fields that can be controlled to disrupt and retrieve biofilm samples for microbial analysis. The second platform is composed of 3-dimensional (3D) micromolded opacifier-infused soft helicoids with embedded catalytic-magnetic NPs that can be visualized via existing radiographic imaging techniques and controlled magnetically inside the root canal, uninterrupted by the soft and hard tissues surrounding the teeth in an ex vivo model. These microrobots placed inside the root canal can remove biofilms and be efficiently guided with microscale precision. The proof-of-concept paradigm described here can be adapted to target difficult-to-reach anatomical spaces in other natural and implanted surfaces in an automated and tether-free manner.},
}
@article {pmid35449342,
year = {2022},
author = {Gómez-Alonso, IS and Estrada-Alemán, ID and Martínez-García, S and Peralta, H and Quintana, ET and Guerrero-Barajas, C and Chávez-Cabrera, C and Rodríguez-Martínez, S and Cancino-Diaz, ME and Cancino-Diaz, JC},
title = {The expression of glycosyltransferases sdgA and sdgB in Staphylococcus epidermidis depends on the conditions of biofilm formation.},
journal = {Archives of microbiology},
volume = {204},
number = {5},
pages = {274},
pmid = {35449342},
issn = {1432-072X},
support = {20210987//Secretaría de Investigación y Posgrado, Instituto Politécnico Nacional/ ; },
mesh = {Animals ; Bacterial Proteins/genetics/metabolism ; Biofilms ; Cathepsin G ; Glycosyltransferases/genetics ; Mice ; *Staphylococcal Infections/microbiology ; *Staphylococcus epidermidis/genetics/metabolism ; },
abstract = {The Staphylococcus aureus SdrG protein is glycosylated by SdgA and SdgB for protection against its degradation by the neutrophil cathepsin G. So far, there is no information about the role of Staphylococcus epidermidis SdgA or SdgB in biofilm-forming; therefore, the focus of this work was to determine the distribution and expression of the sdrG, sdgA and sdgB genes in S. epidermidis under in vitro and in vivo biofilm conditions. The frequencies of the sdrG, sdgA and sdgB genes were evaluated by PCR in a collection of 75 isolates. Isolates were grown in dynamic (non-biofilm-forming) or static (biofilm-forming) conditions. The expression of sdrG, sdgA and sdgB was determined by RT-qPCR in cells grown under dynamic conditions (CGDC), as well as in planktonic and sessile cells from a biofilm and cells adhered to a catheter implanted in Balb/c mice. The sdrG and sdgB genes were detected in 100% of isolates, while the sdgA gene was detected in 71% of the sample (p < 0.001). CGDC did not express sdrG, sdgA and sdgB mRNAs. Planktonic and sessile cells expressed sdrG and sdgB, and the same was observed in cells adhered to the catheter. In particular, one isolate, capable of inducing a biofilm under treatment with cathepsin G, expressed sdrG and sdgB in planktonic and sessile cells and cells adhering to the catheter. This suggests that bacteria require biofilm conditions as an important factor for the transcription of the sdgA, sdgB and sdrG genes.},
}
@article {pmid35448567,
year = {2022},
author = {Ostapska, H and Le Mauff, F and Gravelat, FN and Snarr, BD and Bamford, NC and Van Loon, JC and McKay, G and Nguyen, D and Howell, PL and Sheppard, DC},
title = {Co-Operative Biofilm Interactions between Aspergillus fumigatus and Pseudomonas aeruginosa through Secreted Galactosaminogalactan Exopolysaccharide.},
journal = {Journal of fungi (Basel, Switzerland)},
volume = {8},
number = {4},
pages = {},
pmid = {35448567},
issn = {2309-608X},
support = {558692//Cystic Fibrosis Canada/ ; AM-15//Canadian Glycomics Network (GlycoNet)/ ; W81XWH-15-PRMRP-IIRA//United States Army Medical Command/ ; 81361/CAPMC/CIHR/Canada ; },
abstract = {The mold Aspergillus fumigatus and bacterium Pseudomonas aeruginosa form biofilms in the airways of individuals with cystic fibrosis. Biofilm formation by A. fumigatus depends on the self-produced cationic exopolysaccharide galactosaminogalactan (GAG), while P. aeruginosa biofilms can contain the cationic exopolysaccharide Pel. GAG and Pel are rendered cationic by deacetylation mediated by either the secreted deacetylase Agd3 (A. fumigatus) or the periplasmic deacetylase PelA (P. aeruginosa). Given the similarities between these polymers, the potential for biofilm interactions between these organisms were investigated. P. aeruginosa were observed to adhere to A. fumigatus hyphae in a GAG-dependent manner and to GAG-coated coverslips of A. fumigatus biofilms. In biofilm adherence assays, incubation of P. aeruginosa with A. fumigatus culture supernatants containing de-N-acetylated GAG augmented the formation of adherent P. aeruginosa biofilms, increasing protection against killing by the antibiotic colistin. Fluorescence microscopy demonstrated incorporation of GAG within P. aeruginosa biofilms, suggesting that GAG can serve as an alternate biofilm exopolysaccharide for this bacterium. In contrast, Pel-containing bacterial culture supernatants only augmented the formation of adherent A. fumigatus biofilms when antifungal inhibitory molecules were removed. This study demonstrates biofilm interaction via exopolysaccharides as a potential mechanism of co-operation between these organisms in chronic lung disease.},
}
@article {pmid35448388,
year = {2022},
author = {Lu, D and Bai, H and Liao, B},
title = {Comparison between Thermophilic and Mesophilic Membrane-Aerated Biofilm Reactors-A Modeling Study.},
journal = {Membranes},
volume = {12},
number = {4},
pages = {},
pmid = {35448388},
issn = {2077-0375},
support = {RGPIN-2014-03727//Natural Sciences and Engineering Research Council/ ; },
abstract = {The concept of thermophilic membrane-aerated biofilm reactor (ThMABR) is studied by modeling. This concept combines the advantages and overcomes the disadvantages of conventional MABR and thermophilic aerobic biological treatment and has great potential to develop a new type of ultra-compact, highly efficient bioreactor for high-strength wastewater and waste gas treatments. Mathematical modeling was conducted to investigate the impact of temperature (mesophilic vs. thermophilic) and oxygen partial pressure on oxygen and substrate concentration profiles, membrane-biofilm interfacial oxygen concentration, oxygen penetration distance, and oxygen and substrate fluxes into biofilms. The general trend of oxygen transfer and substrate flux into biofilm between ThAnMBR and MMABR was verified by the experimental results in the literature. The results from modeling studies indicate that the ThMABR has significant advantages over the conventional mesophilic MABR in terms of improved oxygen and pollutant flux into biofilms and biodegradation rates, and an optimal biofilm thickness exists for maximum oxygen and substrate fluxes into the biofilm.},
}
@article {pmid35447572,
year = {2022},
author = {Qian, Y and Guo, Y and Shen, J and Qin, Y and Li, YY},
title = {Biofilm growth characterization and treatment performance in a single stage partial nitritation/anammox process with a biofilm carrier.},
journal = {Water research},
volume = {217},
number = {},
pages = {118437},
doi = {10.1016/j.watres.2022.118437},
pmid = {35447572},
issn = {1879-2448},
mesh = {*Ammonium Compounds ; Anaerobic Ammonia Oxidation ; Biofilms ; Bioreactors ; Denitrification ; Nitrogen ; Oxidation-Reduction ; Phosphorus ; *Sewage ; Waste Water ; },
abstract = {Biofilm carriers can avoid microorganism washout while maintaining a high amount of biomass, but are also associated with a long biofilm formation period and biofilm aging. A single stage partial nitritation/anammox process (single stage PN/A) reactor was setup to study the biofilm growth characterization and treatment performance under an NLR of 0.53 to 0.90 gN/L/d over one year. Biofilm growth was divided into three stages: the formation stage, maturation stage and aging stage. The initial biofilm was observed at day 84. A nitrogen removal efficiency of 83.4% was achieved at an NLR of 0.90 gN/L/d during the mature biofilm stage. Starvation, nitrogen gas accumulation and hydroxyapatite formation resulted in biofilm aging. After mechanical stirring treatment, biofilm reactivation was achieved by biofilm re-formation within one month. There is clear potential for phosphorus recovery, as indicated by the 5.24% - 6.29% phosphorus content in the biofilm (similar to the 5%-7% phosphorus content in enhanced biological phosphate removal sludge). The AnAOB genera abundance in the biofilm maintained at a high level of 18.25%-32.31%, while the abundance of AnAOB increased from the initial 4.10% to 13.78% after mechanical stirring treatment in the suspended sludge ensured biofilm reactivation. The results of this study clearly show that mechanical stirring treatment can be used to achieve the biofilm reactivation as the biofilm fills with the hollow cylindrical carrier. This study has potential as a useful reference for the realization of the wide application of the biofilm single stage PN/A process in the future.},
}
@article {pmid35447397,
year = {2022},
author = {Chung, TH and Zakaria, BS and Meshref, MNA and Dhar, BR},
title = {Enhancing quorum sensing in biofilm anode to improve biosensing of naphthenic acids.},
journal = {Biosensors &amp; bioelectronics},
volume = {210},
number = {},
pages = {114275},
doi = {10.1016/j.bios.2022.114275},
pmid = {35447397},
issn = {1873-4235},
abstract = {The feasibility of enhancing quorum sensing (QS) in anode biofilm to improve the quantifications of commercial naphthenic acid concentrations (9.4-94 mg/L) in a microbial electrochemical cell (MXC) based biosensor was demonstrated in this study. First, three calibration methods were systematically compared, and the charging-discharging operation was selected for further experiments due to its 71-227 folds higher electrical signal outputs than the continuous closed-circuit operation and cyclic voltammetry modes. Then, the addition of acylase (5 μg/L) as an exogenous QS autoinducer (acylase) was investigated, which further improved the biosensor's electrical signal output by ∼70%, as compared to the control (without acylase). The addition of acylase increased the relative expression of QS-associated genes (lasR, lasI, rhlR, rhlI, lasA, and luxR) by 7-100%, along with increased abundances of known electroactive bacterial genera, such as Geobacter (from 42% to 47%) and Desulfovibrio (from 6% to 11%). Furthermore, toxicities of different NAs concentrations measured with the Microtox bioassay test were correlated with corresponding electrical signals, indicating that MXC-biosensor can provide a dual platform for rapid assessment of both NA concentrations and NA-associated toxicity.},
}
@article {pmid35447190,
year = {2022},
author = {Wang, T and Zhang, T and Dai, X and Wang, W and Wang, J},
title = {Control strategies for biofilm control in reclaimed water distribution systems from the perspective of microbial antagonism and electrochemistry.},
journal = {The Science of the total environment},
volume = {834},
number = {},
pages = {155289},
doi = {10.1016/j.scitotenv.2022.155289},
pmid = {35447190},
issn = {1879-1026},
abstract = {Biofilm formation in reclaimed water (RW) distribution systems presents significant technical challenges to RW utilization. Two main technologies to control biofilm formation, microbial antagonism (MA) and electrochemical oxidation (EO), are not yet widely used in drip irrigation systems (DIS) and their mechanisms of action need further clarification. In this study, we first showed that the MA and EO treatments reduced biofilm formation by about 62% and 68%, respectively, and extracellular polymeric substance (EPS) content by 14% and 49%, respectively, in biofilms compared with raw RW type 1 (R-RW1) in unused pipes, thus effectively improving the performance of DIS. When MA-RW and EO-RW were applied to already clogged systems, the degree of clogging alleviation varied depending on the severity of the original clogging. We recommend adding the antagonist, Bacillus subtilis, to RW at 25% clogging for the maximum effect and to slow the microbial adaptation process. Compared to MA, the recovery effect of EO was slower initially but lasted longer and had a significantly better alleviating effect on severely clogged pipelines. Illumina Mi-SEQ high-throughput sequencing data showed that both MA and EO resulted in a significant decrease in microbial diversity, dynamic changes in bacterial community structure, and disruption of network interaction and network modularity. Meanwhile, both treatments promoted the growth of specific microorganisms, enhanced the interaction between certain microbial components, and improved the efficiency of information, matter, and energy exchange within the modules. In summary, we verified the dredging effect of two strategies on DIS under different water conditions, revealed the differences in their mechanisms of action, and proposed their application scenarios. Our results will help improve the efficiency of RW in agricultural drip irrigation systems and effectively reduce maintenance costs.},
}
@article {pmid35445489,
year = {2022},
author = {Mahmoudi, M and Sadeghifard, N and Maleki, A and Yeo, CC and Ghafourian, S},
title = {relBE toxin-antitoxin system as a reliable anti-biofilm target in Pseudomonas aeruginosa.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/jam.15585},
pmid = {35445489},
issn = {1365-2672},
abstract = {AIMS: The ability of the pathogenic bacterium Pseudomonas aeruginosa to produce biofilms has made it more difficult to treat its infections with current antibiotics. Several genes are involved in biofilm production, and toxin-antitoxin (TA) loci have been reported to be responsible for the regulation of biofilm-associated genes. This study was aimed at evaluating various TA loci in P. aeruginosa to find a reliable target in order to disrupt biofilm formation.<br><br>METHODS AND RESULTS: Thirty clinical isolates of P. aeruginosa were assessed for biofilm production as well as the presence of various TA loci in their genomes. The relBETA locus was present in all 30 P. aeruginosa isolates but its expression was not detectable in isolates that did not show biofilm production. Quantitative real-time -PCR (q-PCR) also demonstrated that the expression of relBE was higher in isolates with stronger biofilm-producing capability. Knocking out the relBE locus in one biofilm-producing P. aeruginosa isolate led to the cessation of biofilm-producing capacity in that isolate and eliminated the expression of ndvB, which is among the genes involved in biofilm production.<br><br>CONCLUSIONS: These results inferred the involvement of relBE TA locus in the regulation of biofilm production in P. aeruginosa and indicated the possibility of relBE as an anti-biofilm target for this pathogen.},
}
@article {pmid35443798,
year = {2022},
author = {Tuncer, G and Aktas, Z and Basaran, S and Cagatay, A and Eraksoy, H},
title = {Biofilm formation of panresistant Klebsiella pneumoniae.},
journal = {Future microbiology},
volume = {},
number = {},
pages = {},
doi = {10.2217/fmb-2021-0108},
pmid = {35443798},
issn = {1746-0921},
support = {project number: 30012//Scientific Research Projects Coordination Unit/ ; },
abstract = {Introduction: The authors aimed to investigate the biofilm-forming features of panresistant Klebsiella pneumoniae (PRKp). Material &amp; methods: The biofilm formations were shown under light microscope and laser scanning confocal microscopy. The optical densities of the wells were measured and classified according to biofilm-forming capacities. Results: The ratio of biofilm-forming K. pneumoniae was established to be 100%. All isolates were found to form high-level biofilms in classification compared with positive and negative controls. No significant difference was detected in the biofilm-forming capacities of K. pneumoniae strains isolated from different sample types. Conclusion: No previous study associated with PRKp isolates was identified in the literature search. There is a need for different approaches characterizing the biofilm-forming features of PRKp.},
}
@article {pmid35443583,
year = {2022},
author = {Bayatipour, Z and Sadeghifard, N and Ghafourian, S and Kalani, BS and Asadollahi, P and Azizi-Jalilian, F and Pakzad, I},
title = {Effect of Chlorhexidine (CHX) and Hydrogen Peroxide (H2O2) on the Biofilm Formation of Enterococcus faecalis.},
journal = {Clinical laboratory},
volume = {68},
number = {4},
pages = {},
doi = {10.7754/Clin.Lab.2021.210458},
pmid = {35443583},
issn = {1433-6510},
mesh = {Biofilms ; *Chlorhexidine/pharmacology ; *Enterococcus faecalis/genetics ; Humans ; Hydrogen Peroxide/pharmacology ; Microbial Sensitivity Tests ; },
abstract = {BACKGROUND: Biofilm makes bacteria resistant to antimicrobial agents and facilitates the transmission of infectious diseases in hospitals. Disinfectant compounds are frequently used to control surface contamination. This study was designed to investigate the effect of chlorhexidine (CHX) and hydrogen peroxide (H2O2) on biofilm formation of Enterococcus faecalis.<br><br>METHODS: This study was performed on 40 E. faecalis clinical isolates. After the determination of MIC, the effect of different concentrations of CHX and H2O2 on the biofilm formation was evaluated. Also, the relative expression level of the studied biofilm genes, following exposure to sublethal concentration of CHX and H2O2, was assessed using quantitative reverse transcription PCR (qRT-PCR).<br><br>RESULTS: The frequency of the asa1, efaA, epaI, and esp biofilm genes were 80%, 92.5%, 100%, and 75%, respectively. Various concentrations of CHX increased the biofilm mass in E. faecalis. Also, the combination of CHX and H2O2 at sub-minimal inhibitory concentrations, significantly elevated the expression of asa1, epaI, and esp genes.<br><br>CONCLUSIONS: The results of this study showed that the improper use of disinfectants can increase the ability of biofilm formation in E. faecalis and may cause selective pressure leading to the emergence of biocide-resistant microorganisms.},
}
@article {pmid35441624,
year = {2022},
author = {Wang, Y and Shukla, A},
title = {Bacteria-responsive biopolymer-coated nanoparticles for biofilm penetration and eradication.},
journal = {Biomaterials science},
volume = {},
number = {},
pages = {},
doi = {10.1039/d2bm00361a},
pmid = {35441624},
issn = {2047-4849},
abstract = {Biofilm infections are common and can be extremely difficult to treat. Nanoparticles that respond to multiple bacterial stimuli have the potential to successfully prevent and eradicate biofilms. Here, we developed a hyaluronic acid and chitosan coated, antibiotic loaded gelatin nanoparticle, which can undergo hyaluronidase- and gelatinase-mediated degradation regulated by chitosan protonation and swelling in the acidic biofilm microenvironment. We examined the antibiofilm properties of these nanoparticles using a Gram-negative biofilm forming pathogenic bacteria, Vibrio vulnificus. Non-drug loaded responsive nanoparticle formulations exhibited excellent biofilm penetration and retention in preformed V. vulnificus biofilms. Drug loaded formulations were found to exhibit excellent biofilm eradication efficacy, eliminating the biofilm matrix and effectively causing bacterial cell death, which was not observed for treatment with free drug at equivalent concentrations. Overall, these multi-stimuli-responsive nanoparticles have the potential to provide effective and efficient antibiofilm treatment.},
}
@article {pmid35439517,
year = {2022},
author = {Hua, ZL and Wang, YF and Zhang, JY and Li, XQ and Yu, L},
title = {Removal of perfluoroalkyl acids and dynamic succession of biofilm microbial communities in the decomposition process of emergent macrophytes in wetlands.},
journal = {The Science of the total environment},
volume = {834},
number = {},
pages = {155295},
doi = {10.1016/j.scitotenv.2022.155295},
pmid = {35439517},
issn = {1879-1026},
abstract = {Perfluoroalkyl acids (PFAAs) are emerging contaminants that pose significant environmental and health concerns. Water-sediment-macrophyte residue systems were established to clarify the removal efficiency of PFAAs, explore possible removal pathways, and profile the dynamic succession of biofilm microbial communities in the decomposition process. These systems were fortified with 12 PFAAs at three concentration levels. Iris pseudacorus and Alisma orientale were selected as the decomposing emergent macrophytes. The removal rates in the treatments with residues of I. pseudacorus (IP) and A. orientale (AO) were 34.4% to 88.9% and 36.5% to 89.9%, respectively, which were higher than those in the control groups (CG) (30.3% to 86.9%), suggesting that decomposition could alter the removal of PFAAs. Sediment made the greatest contributions (preloaded 14.5% to 77.8% of PFAAs in IP, 14.3% to 78.2% in AO, and 27.4% to 71.9% in CG). PFAAs could also be removed by macrophyte residue sorption (0.0190% to 13.0% in IP and 0.016% to 15.6% in AO) and bioaccumulation of residual biofilm (the contributions of biofilm microbes and their extracellular polymeric substances were 0.0110% to 3.93% and 0.918% to 34.4%, respectively, in IP and 0.0141% to 4.65% and 1.49% to 34.1%, respectively, in AO). Significant correlations were observed between sediment/residue adsorption and bioaccumulation of biofilm microbes, and were significantly correlated with perfluoroalkyl chain length (p < 0.05). The dynamic succession of residual biofilm microbial communities was investigated. The largest difference was found at the preliminary stage. The most similar communities were found in AO on day 70 (with specific genera Macellibacteroides and WCHB1-32) and in IP on day 35 (with specific genera Aeromonas and Flavobacterium). This study is useful to understand the removal of PFAAs during the decomposition process, providing further assistance in removing PFAAs during the life cycle of macrophytes in wetlands.},
}
@article {pmid35438974,
year = {2022},
author = {Gu, X and Huang, D and Chen, J and Li, X and Zhou, Y and Huang, M and Liu, Y and Yu, P},
title = {Bacterial Inactivation and Biofilm Disruption through Indigenous Prophage Activation Using Low-Intensity Cold Atmospheric Plasma.},
journal = {Environmental science &amp; technology},
volume = {},
number = {},
pages = {},
doi = {10.1021/acs.est.2c01516},
pmid = {35438974},
issn = {1520-5851},
abstract = {Biofilms can be pervasive and problematic in water treatment and distribution systems but are difficult to eradicate due to hindered penetration of antimicrobial chemicals. Here, we demonstrate that indigenous prophages activated by low-intensity plasma have the potential for efficient bacterial inactivation and biofilm disruption. Specifically, low-intensity plasma treatment (i.e., 35.20 W) elevated the intracellular oxidative reactive species (ROS) levels by 184%, resulting in the activation of prophage lambda (λ) within antibiotic-resistant Escherichia coli K-12 (lambda+) [E. coli (λ+)]. The phage activation efficiency was 6.50-fold higher than the conventional mitomycin C induction. Following a cascading effect, the activated phages were released upon the lysis of E. coli (λ+), which propagated further and lysed phage-susceptible E. coli K-12 (lambda-) [E. coli (λ-)] within the biofilm. Bacterial intracellular ROS analysis and ROS scavenger tests revealed the importance of plasma-generated ROS (e.g., •OH, 1O2, and •O2-) and associated intracellular oxidative stress on prophage activation. In a mixed-species biofilm on a permeable membrane surface, our "inside-out" strategy could inactivate total bacteria by 49% and increase the membrane flux by 4.33-fold. Furthermore, the metagenomic analysis revealed that the decrease in bacterial abundance was closely associated with the increase in phage levels. As a proof-of-concept, this is the first demonstration of indigenous prophage activations by low-intensity plasma for antibiotic-resistant bacterial inactivation and biofilm eradication, which opens up a new avenue for managing associated microbial problems.},
}
@article {pmid35438787,
year = {2022},
author = {Hsieh, ML and Kiel, N and Jenkins, LMM and Ng, WL and Knipling, L and Waters, CM and Hinton, DM},
title = {The Vibrio cholerae master regulator for the activation of biofilm biogenesis genes, VpsR, senses both cyclic di-GMP and phosphate.},
journal = {Nucleic acids research},
volume = {50},
number = {8},
pages = {4484-4499},
pmid = {35438787},
issn = {1362-4962},
support = {F30 GM123632/GM/NIGMS NIH HHS/United States ; R01 GM109259/GM/NIGMS NIH HHS/United States ; R01 AI158433/AI/NIAID NIH HHS/United States ; R35 GM139537/GM/NIGMS NIH HHS/United States ; },
mesh = {Bacterial Proteins/genetics/metabolism ; Biofilms ; Cyclic GMP/analogs &amp; derivatives/metabolism ; DNA-Binding Proteins/genetics ; DNA-Directed RNA Polymerases/genetics/metabolism ; Gene Expression Regulation, Bacterial ; Phosphates/metabolism ; Sigma Factor/genetics/metabolism ; *Vibrio cholerae/metabolism ; },
abstract = {Vibrio cholerae biofilm formation/maintenance is controlled by myriad factors; chief among these are the regulator VpsR and cyclic di-guanosine monophosphate (c-di-GMP). VpsR has strong sequence similarity to enhancer binding proteins (EBPs) that activate RNA polymerase containing sigma factor σ54. However, we have previously shown that transcription from promoters within the biofilm biogenesis/maintenance pathways uses VpsR, c-di-GMP and RNA polymerase containing the primary sigma factor (σ70). Previous work suggested that phosphorylation of VpsR at a highly conserved aspartate, which is phosphorylated in other EBPs, might also contribute to activation. Using the biofilm biogenesis promoter PvpsL, we show that in the presence of c-di-GMP, either wild type or the phospho-mimic VpsR D59E activates PvpsL transcription, while the phospho-defective D59A variant does not. Furthermore, when c-di-GMP levels are low, acetyl phosphate (Ac∼P) is required for significant VpsR activity in vivo and in vitro. Although these findings argue that VpsR phosphorylation is needed for activation, we show that VpsR is not phosphorylated or acetylated by Ac∼P and either sodium phosphate or potassium phosphate, which are not phosphate donors, fully substitutes for Ac∼P. We conclude that VpsR is an unusual regulator that senses phosphate directly, rather than through phosphorylation, to aid in the decision to form/maintain biofilm.},
}
@article {pmid35438634,
year = {2022},
author = {Zhang, J and Wu, H and Wang, D and Wang, L and Cui, Y and Zhang, C and Zhao, K and Ma, L},
title = {Intracellular glycosyl hydrolase PslG shapes bacterial cell fate, signaling, and the biofilm development of Pseudomonas aeruginosa.},
journal = {eLife},
volume = {11},
number = {},
pages = {},
pmid = {35438634},
issn = {2050-084X},
support = {2018YFA0902102,2021YFA0909500,2019YFC804104,and 2019YFA0905501//the National Key R &amp; D of China/ ; 91951204,21621004,32070033//the National natural science Foundation of China/ ; 2018YFA0902102//National Key Research and Development Program of China/ ; 91951204//National Natural Science Foundation of China/ ; 32070033//National Natural Science Foundation of China/ ; 21621004//National Natural Science Foundation of China/ ; 2019YFA0905501//National Key Research and Development Program of China/ ; 2019YFC804104//National Key Research and Development Program of China/ ; 2021YFA0909500//National Key Research and Development Program of China/ ; },
mesh = {Bacterial Proteins/genetics/metabolism ; *Biofilms ; Cyclic GMP ; Gene Expression Regulation, Bacterial ; Glycoside Hydrolases/genetics/metabolism ; Polysaccharides ; *Pseudomonas aeruginosa/physiology ; },
abstract = {Biofilm formation is one of most important causes leading to persistent infections. Exopolysaccharides are usually a main component of biofilm matrix. Genes encoding glycosyl hydrolases are often found in gene clusters that are involved in the exopolysaccharide synthesis. It remains elusive about the functions of intracellular glycosyl hydrolase and why a polysaccharide synthesis gene cluster requires a glycosyl hydrolase-encoding gene. Here, we systematically studied the physiologically relevant role of intracellular PslG, a glycosyl hydrolase whose encoding gene is co-transcribed with 15 psl genes, which is responsible for the synthesis of exopolysaccharide PSL, a key biofilm matrix polysaccharide in opportunistic pathogen Pseudomonas aeruginosa. We showed that lack of PslG or its hydrolytic activity in this opportunistic pathogen enhances the signaling function of PSL, changes the relative level of cyclic-di-GMP within daughter cells during cell division and shapes the localization of PSL on bacterial periphery, thus results in long chains of bacterial cells, fast-forming biofilm microcolonies. Our results reveal the important roles of intracellular PslG on the cell fate and biofilm development.},
}
@article {pmid35437846,
year = {2022},
author = {Visperas, A and Santana, D and Klika, AK and Higuera-Rueda, CA and Piuzzi, NS},
title = {Current treatments for biofilm-associated periprosthetic joint infection and new potential strategies.},
journal = {Journal of orthopaedic research : official publication of the Orthopaedic Research Society},
volume = {},
number = {},
pages = {},
doi = {10.1002/jor.25345},
pmid = {35437846},
issn = {1554-527X},
abstract = {Periprosthetic joint infection (PJI) remains a devastating complication after total joint arthroplasty. Bacteria involved in these infections are notorious for adhering to foreign implanted surfaces and generating a biofilm matrix. These biofilms protect the bacteria from antibiotic treatment and the immune system making eradication difficult. Current treatment strategies including debridement, antibiotics, and implant retention, and one- and two-stage revisions still present a relatively high overall failure rate. One of the main shortcomings that has been associated with this high failure rate is the lack of a robust approach to treating bacterial biofilm. Therefore, in this review, we will highlight new strategies that have the potential to combat PJI by targeting biofilm integrity, therefore giving antibiotics and the immune system access to the internal network of the biofilm structure. This combination antibiofilm/antibiotic therapy may be a new strategy for PJI treatment while promoting implant retention.},
}
@article {pmid35436977,
year = {2022},
author = {Yin, L and Cheng, B and Tu, J and Shao, Y and Song, X and Pan, X and Qi, K},
title = {YqeH contributes to avian pathogenic Escherichia coli pathogenicity by regulating motility, biofilm formation, and virulence.},
journal = {Veterinary research},
volume = {53},
number = {1},
pages = {30},
pmid = {35436977},
issn = {1297-9716},
support = {31772707//Natural Science Foundation of China/ ; 31972644//Natural Science Foundation of China/ ; 2108085QC137//Natural Science Foundation of Anhui Province/ ; },
mesh = {Animals ; Biofilms ; Chick Embryo ; Chickens ; Escherichia coli/physiology ; *Escherichia coli Infections/veterinary ; *Escherichia coli Proteins/genetics ; *Poultry Diseases ; Virulence ; Virulence Factors/genetics ; },
abstract = {Avian pathogenic Escherichia coli (APEC) is a pathotype of extraintestinal pathogenic E. coli and one of the most serious infectious diseases of poultry. It not only causes great economic losses to the poultry industry, but also poses a serious threat to public health worldwide. Here, we examined the role of YqeH, a transcriptional regulator located at E. coli type III secretion system 2 (ETT2), in APEC pathogenesis. To investigate the effects of YqeH on APEC phenotype and virulence, we constructed a yqeH deletion mutant (APEC40-ΔyqeH) and a complemented strain (APEC40-CΔyqeH) of APEC40. Compared with the wild type (WT), the motility and biofilm formation of APEC40-ΔyqeH were significantly reduced. The yqeH mutant was highly attenuated in a chick infection model compared with WT, and showed severe defects in its adherence to and invasion of chicken embryo fibroblast DF-1 cells. However, the mechanisms underlying these phenomena were unclear. Therefore, we analyzed the transcriptional effects of the yqeH deletion to clarify the regulatory mechanisms of YqeH, and the role of YqeH in APEC virulence. The deletion of yqeH downregulated the transcript levels of several flagellum-, biofilm-, and virulence-related genes. Our results demonstrate that YqeH is involved in APEC pathogenesis, and the reduced virulence of APEC40-ΔyqeH may be related to its reduced motility and biofilm formation.},
}
@article {pmid35432252,
year = {2022},
author = {Winkelströter, LK and Bezirtzoglou, E and Tulini, FL},
title = {Editorial: Natural Compounds and Novel Sources of Antimicrobial Agents for Food Preservation and Biofilm Control.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {856858},
pmid = {35432252},
issn = {1664-302X},
}
@article {pmid35430267,
year = {2022},
author = {Chen, X and Tyagi, A and Vijayalakshmi, S and Chelliah, R and Shabbir, U and Oh, DH},
title = {Anti-adhesion and anti-biofilm activity of slightly acidic electrolyzed water combined with sodium benzoate against Streptococcus mutans: A novel ecofriendly oral sanitizer to prevent cariogenesis.},
journal = {Microbial pathogenesis},
volume = {166},
number = {},
pages = {105535},
doi = {10.1016/j.micpath.2022.105535},
pmid = {35430267},
issn = {1096-1208},
mesh = {Biofilms ; *Dental Caries/prevention &amp; control ; Humans ; Sodium Benzoate/pharmacology ; *Streptococcus mutans ; Water ; },
abstract = {Streptococcus mutans (S. mutans) can promote the establishment of high acidic biofilms and therefore have contribution to the development of dental caries. Alleviating the acidic environment and/or disrupting the structure of S. mutans biofilm are effective approaches against dental caries, rather than killing the microorganisms. The anti-biofilm effect of slightly acidic electrolyzed water (SAEW) is entirely based on the hypochlorous acid and ROS generation. In this study, sodium benzoate (NaB) acts as a pH adjuster and enhances SAEW's anti-biofilm activity. The results showed that the SAEW combined with NaB (SAEW + NaB) is highly effective in controlling biofilm. The adhesive strength of biofilm was significantly reduced by SAEW, and NaB was found to have a synergy effect with SAEW. Biofilm treated by SAEW + NaB was entirely removed by 60 s of ultrasonic wave, whereas the untreated biofilm can only be removed to a lesser extent. Atomic force microscope (AFM) analysis revealed that SAEW and NaB reduced the height of S. mutans biofilm. The metabolites derived from biofilm positively changed during the periodic 1-min treat, the production of lactic acid was hindered by the treatment. Altogether, these findings suggested a novel therapeutic intervention against S. mutans biofilm by targeting the cariogenic action.},
}
@article {pmid35429876,
year = {2022},
author = {Ma, B and Seyedi, S and Wells, E and McCarthy, D and Crosbie, N and Linden, KG},
title = {Inactivation of biofilm-bound bacterial cells using irradiation across UVC wavelengths.},
journal = {Water research},
volume = {217},
number = {},
pages = {118379},
doi = {10.1016/j.watres.2022.118379},
pmid = {35429876},
issn = {1879-2448},
mesh = {Biofilms ; Chlorine ; Disinfection/methods ; *Drinking Water ; Ultraviolet Rays ; *Water Purification/methods ; },
abstract = {Opportunistic pathogens (OPs), such as Pseudomonas spp., Legionella spp., and mycobacteria, have been detected in biofilms in drinking water distribution systems and water storage tanks and pose potential risks to finished drinking water quality and safety. Emerging UV technologies, such as UV light emitting diodes (LEDs) and krypton chloride (KrCl*) excimers, could provide an alternative to chemical-based secondary disinfection (i.e., chlorine or chloramines) for controlling biofilm-bound OPs. UV systems offer long lifetimes, ability to select wavelength, small size with high power density, and limited-to-no disinfection by-product formation. In this study, inactivation of biofilm-bound Pseudomonas aeruginosa cells across different maturities was investigated using five UVC devices with different peak emission wavelengths, including a KrCl* excimer (222 nm), a low pressure mercury vapor lamp (254 nm), and three UV LEDs (260 nm, 270 nm, and 282 nm). The UV transmittance and absorbance through the biofilm structure was also documented for the first time using a unique approach. Our results show all UVC devices can inactivate biofilm-bound P. aeruginosa cells up to a point, among which the UV LED with peak emission at 270 nm provided the best disinfection performance. UV sensitivities of biofilm-bound cells decreased with biofilm maturity and while initial rates of inactivation were high, no more than 1.5-2.5 log reduction was possible. Re-suspended biofilm bacteria in aqueous solution were highly sensitive to UV, reaching greater than 6 log reduction. UV shielding by biofilm constituents was observed and was likely one of the reasons for UV resistance but did not fully explain the difference in UV sensitivity between biofilm-bound cells versus planktonic cells. This study improves upon fundamental knowledge and provides guidance for innovative designs using emerging UV technologies for biofilm and pathogen control in water distribution systems.},
}
@article {pmid35429565,
year = {2022},
author = {Li, Y and Wang, X and Wang, Y and Sun, Y and Xia, S and Zhao, J},
title = {Effect of biofilm colonization on Pb(II) adsorption onto poly(butylene succinate) microplastic during its biodegradation.},
journal = {The Science of the total environment},
volume = {833},
number = {},
pages = {155251},
doi = {10.1016/j.scitotenv.2022.155251},
pmid = {35429565},
issn = {1879-1026},
abstract = {Few studies have mentioned the enrichment of heavy metal pollutants on microplastics derived from degradable plastics. This study investigated the adsorption behavior of Pb(II) onto biodegradable poly(butylene succinate) (PBS) microplastics during its biodegradation. The results indicated that Pb(II) adsorbed by biofilm-colonized biodegraded-PBS microplastics (B-PBS) was about 10-folds higher than that of virgin PBS (647.09 μg·g-1 versus 64.13 μg·g-1) due to the biofilm colonization and the degradation of PBS. After removing the biofilm, the biodegraded PBS still had high Pb(II) adsorption capacity, which was attributed to the complexation of Pb(II) and the stably adhered extracellular polymeric substances (EPS). Pb(II) adsorption onto both virgin PBS and B-PBS was highly pH-dependent, its adsorption on virgin PBS was dominated by electrostatic interaction, while as for B-PBS, the adsorption mechanisms mainly involved the coordination/complexation of Pb(II) and the EPS components on the colonized biofilm, surface complexation, and electrostatic interaction. This study suggested that the enrichment of heavy metal pollutants onto the biodegradable microplastics may pose risks to the aquatic ecosystem.},
}
@article {pmid35429560,
year = {2022},
author = {Suzhen, H and Xuhui, H and Hongkuan, C and Qixuan, S and Xingzhang, L and Zheng, Z},
title = {Role of phosphorus in Vallisneria natans and biofilm exposure to Pb2+ and Cd2+ stress.},
journal = {The Science of the total environment},
volume = {835},
number = {},
pages = {155235},
doi = {10.1016/j.scitotenv.2022.155235},
pmid = {35429560},
issn = {1879-1026},
abstract = {Phosphorus (P) could improve the stress resistance and adaptability of submerged macrophytes. This study investigated the physiological and biochemical responses of plants exposed to different P and Pb, Cd concentrations. Alterations of protein synthesis, the DNA methylation (5-mC) level, and the microbial community of biofilm were also evaluated. Results indicated that lower P (0.5 mg·L-1) could promote plant growth and metal enrichment while mitigating the toxicity of metals. Higher P (5.0 mg·L-1) induced a degree of oxidative stress, as confirmed by increased activity of superoxide dismutase, peroxidase, and acid phosphatase, as well as increased malondialdehyde contents. While the variation of metallothionein synthesis and DNA methylation level of the plant was dependent on the level of P and metals in the water. These responses indicated potential mechanisms of P detoxification and intoxication. In addition, more abundant microbial communities were observed in biofilms exposed to P and metals. These findings provide theoretical support for the metal detoxification of P in submerged plants.},
}
@article {pmid35429103,
year = {2022},
author = {Garakouei, SR and Issazadeh, K and Zamani, H and Rakhshaee, R and Shahriarinour, M},
title = {Characterization of oxaliplatin removal by multispecies bacterial populations in moving bed biofilm and suspended-biomass reactors.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/jam.15579},
pmid = {35429103},
issn = {1365-2672},
support = {//University of Guilan/ ; },
abstract = {AIMS: This work aimed to characterize the oxaliplatin removal potential of multispecies microbial populations using the suspended-biomass (SB) and moving bed biofilm (MBB) reactors.<br><br>METHODS AND RESULTS: Bacterial strains were isolated from pharmaceutical wastewater, their oxaliplatin degrading potential was screened and oxaliplatin removal efficacy in multispecies bacterial populations was investigated using HPLC. Five bacterial strains able to degrade oxaliplatin with an oxaliplatin removal efficacy of 21%-52% were isolated. The synthetic consortium including Xenorhabdus spp., Pantoea agglomerans and Bacillus licheniformis showed the highest potential with an oxaliplatin removal efficacy of 88.6% and 94.0% using the SB and MBB reactors, respectively. Also, the consortium reduced the chemical oxygen demand (COD) by 91.6 and 33% in MBB and SB reactors, respectively. A kinetic study showed a faster oxaliplatin removal in MBB (0.134 kg-1) than in the SB reactor (0.101 kg-1). Based on the GS/MS analysis, the overall biochemical pathway of oxaliplatin degradation was hypothesized to be initiated through the oxygenation of diamino-dicyclohexan-platinium complex and the cleavage of the aromatic ring.<br><br>CONCLUSION: Microbial removal of oxaliplatin using MBB and SB reactors seems to be an efficient and promising approach for oxaliplatin removal in pharmaceutical and hospital wastewater treatment plants.<br><br>Employing bacterial populations using the MBB reactor is a promising way to treat pharmaceutical wastewater to reduce the discharge of anticancer drugs into the environment.},
}
@article {pmid35428495,
year = {2022},
author = {Tran, P and Kopel, J and Ray, C and Reed, J and Reid, TW},
title = {Organo-selenium containing dental sealant inhibits biofilm formation by oral bacteria.},
journal = {Dental materials : official publication of the Academy of Dental Materials},
volume = {38},
number = {5},
pages = {848-857},
doi = {10.1016/j.dental.2022.04.006},
pmid = {35428495},
issn = {1879-0097},
mesh = {Biofilms ; *Dental Caries/microbiology/prevention &amp; control ; Humans ; Pit and Fissure Sealants/pharmacology ; *Selenium/pharmacology ; Streptococcus mutans ; },
abstract = {OBJECTIVE: Dental plaque is a complex structure (called a biofilm) that is produced by a community of oral bacteria. As microorganisms accumulate in the oral cavity, bacteria can assemble into biofilms that protect them from antibiotics and disinfectants, which contribute to dental cavities and oral infections that acts as the seed for further infections throughout the body. Therefore, there is great interest in developing dental sealants that can effectively eliminate biofilms formed from an assortment of oral bacteria species.<br><br>METHODS: In previous papers, it was shown that both in vivo and in vitro use of organo-selenium dental sealants have the potential to be an effective method for preventing dental caries and plaque formation. However, our previous in vitro study only examined the effect of the organo-selenium sealants on Streptococcus mutans and salivarius. Since that time, this organo-selenium sealant has been changed to improve its curing time.<br><br>RESULTS: We showed a selenium containing sealant (SeLECT-DefenseTM) can completely eliminate biofilm formation on the sealant at selenium concentrations of 0.25% and higher, by S. salivarius, S. sanguinis, or S. mutans, individually or in combination. This selenium containing sealant can also completely inhibit the same bacteria from growing under the sealant, while control sealant cannot. The selenium containing sealant was tested for stability and it was found to still kill these same bacteria after soaking for the equivalent of one year in PBS (pH 7.4). It was also found that the combination of the three bacteria were also killed by the selenium sealant, thus ruling out potential synergism of the bacteria in forming resistance.<br><br>SIGNIFICANCE: The following study showed that this modified selenium dental sealant effectively eliminates species of bacteria both on and under the dental sealant.},
}
@article {pmid35425831,
year = {2022},
author = {Zhu, C and Zhao, Y and Zhao, X and Liu, S and Xia, X and Zhang, S and Wang, Y and Zhang, H and Xu, Y and Chen, S and Jiang, J and Wu, Y and Wu, X and Zhang, G and Bai, Y and Hu, J and Fotina, H and Wang, L and Zhang, X},
title = {The Antimicrobial Peptide MPX Can Kill Staphylococcus aureus, Reduce Biofilm Formation, and Effectively Treat Bacterial Skin Infections in Mice.},
journal = {Frontiers in veterinary science},
volume = {9},
number = {},
pages = {819921},
pmid = {35425831},
issn = {2297-1769},
abstract = {Staphylococcus aureus is a common pathogen that can cause pneumonia and a variety of skin diseases. Skin injuries have a high risk of colonization by S. aureus, which increases morbidity and mortality. Due to the emergence of multidrug-resistant strains, antimicrobial peptides are considered to be among the best alternatives to antibiotics due to their unique mechanism of action and other characteristics. MPX is an antibacterial peptide extracted from wasp venom that has antibacterial activity against a variety of bacteria. This study revealed that MPX has good bactericidal activity against S. aureus and that its minimum inhibitory concentration (MIC) is 0.08 μM. MPX (4×MIC) can kill 99.9% of bacteria within 1 h, and MPX has good stability. The research on the bactericidal mechanism found that MPX could destroy the membrane integrity, increase the membrane permeability, change the membrane electromotive force, and cause cellular content leakage, resulting in bactericidal activity. Results from a mouse scratch model experiment results show that MPX can inhibit colonization by S. aureus, which reduces the wound size, decreases inflammation, and promotes wound healing. This study reports the activity of MPX against S. aureus and its mechanism and reveals the ability of MPX to treat S. aureus infection in mice, laying the foundation for the development of new drugs for bacterial infections.},
}
@article {pmid35425202,
year = {2022},
author = {Zhang, Y and Ma, R and Chu, H and Zhou, X and Yao, T and Zhang, Y},
title = {Evaluation of the performance of different membrane materials for microalgae cultivation on attached biofilm reactors.},
journal = {RSC advances},
volume = {12},
number = {3},
pages = {1451-1459},
pmid = {35425202},
issn = {2046-2069},
abstract = {Attached microalgae production in wastewater is a promising method to further develop biofilm reactors by reducing economic costs associated with biomass separation and harvesting. However, the reliability of materials to support such adherence needs further investigation. Five common microfiltration membranes were evaluated in this study to assess their influence on the efficacy of harvesting Chlorella pyrenoidosa. The material-to-material, algae-to-algae, and algae-to-material interactions were studied based on the Extended Derjaguin, Landau, Verwey, Overbeek (XDLVO) theory. The results showed that Chlorella pyrenoidosa was hydrophobic and that the algae particles derived from this algae type tended to agglomerate. Furthermore, the algae-membrane adhesion free energy further validated the accumulation of biomass in the experiments - the cellulose acetate nitrate (CACN) membrane and the cellulose acetate (CA) membrane obtained an optical biomass production of 59.93 and 51.27 g m-2. The presence of these interactions promoted the adhesion of more microalgae particles to the membrane. Moreover, the relationship between the algae-membrane and the distance at which the microalgae approached the membrane surface was simulated. The study indicated that the XDLVO theory could be successfully applied to the mechanism for the adhesion of the attached culture of Chlorella pyrenoidosa to the membrane material.},
}
@article {pmid35423457,
year = {2021},
author = {Dargahi, A and Shokoohi, R and Asgari, G and Ansari, A and Nematollahi, D and Samarghandi, MR},
title = {Moving-bed biofilm reactor combined with three-dimensional electrochemical pretreatment (MBBR-3DE) for 2,4-D herbicide treatment: application for real wastewater, improvement of biodegradability.},
journal = {RSC advances},
volume = {11},
number = {16},
pages = {9608-9620},
pmid = {35423457},
issn = {2046-2069},
abstract = {2,4-Dichlorophenoxyacetic acid (2,4-D) is a herbicide that is considered as a carcinogenic and highly toxic contaminant, and due to its biological and chemical stability, its degradation is very difficult. Therefore, this study aimed to investigate a hybrid system's efficiency of three-dimensional electrochemical (3DE) process and a moving bed biofilm reactor (MBBR) in removing 2,4-D herbicides from aqueous solutions. In this experimental study, the electrochemical degradation of 2,4-D herbicide in a 3DE process with a G/β-PbO2 anode was first investigated as a pretreatment process. Then, in the post-treatment stage, MBBR with continuous flow was used. The amount of aeration in the MBBR reactor was 4 L min-1, and the amount of dissolved oxygen (DO) was in the range of 3-5 mg L-1. The effect of various parameters such as hydraulic retention time (HRT) and filling ratio were investigated. The amount of sewage injection was set between 0.001-0.004 L min-1. Routine microbiological biochemical tests were used to detect bacteria. BOD5/COD, COD/TOC, AOS, and COS ratio parameters were used to determine the biodegradability of 2.4-D due to the effluent of the 3DE process. The results showed that with increasing current density, decreasing pH, decreasing herbicide concentration and increasing electrolysis time, the herbicide degradation efficiency increased by 3DE pretreatment process. Based on the results of MBBR post-treatment process efficiency, with increasing HRT and filling ratio, the herbicide removal efficiency increased. According to the results, the highest removal efficiencies of 2,4-D and COD herbicides were obtained during HRT of 24 h, and the filling ratio of 70% were 97.33% and 88.95%, respectively. The consortium of 2,4-D degrading bacteria identified in this study included E. coli, Enterobacter spp., Bacillus spp., Alcaligenes spp., Proteus spp., Acinetobacter spp., Pseudomonas spp., Arthrobacter, and Brevundimonas vesicularis. In the MBBR biological process, the reaction kinetics followed the Grau second-order model (R 2 = 0.98). In general, the results showed that the combined process of 3DE with G/β-PbO2 anode and MBBR biological process has relatively high efficiency in 2,4-D herbicide degradation and can be used as a suitable complementary treatment method in wastewater containing non-degradable compounds such as phenoxy herbicides, e.g., 2,4-D should be used.},
}
@article {pmid35422789,
year = {2022},
author = {Yin, WL and Xie, ZY and Zeng, YH and Zhang, J and Long, H and Ren, W and Zhang, X and Cai, XN and Huang, AY},
title = {Two (p)ppGpp Synthetase Genes, relA and spoT, Are Involved in Regulating Cell Motility, Exopolysaccharides Production, and Biofilm Formation of Vibrio alginolyticus.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {858559},
pmid = {35422789},
issn = {1664-302X},
abstract = {The stringent response mediated by the signal molecule (p)ppGpp is involved in response to multiple environmental stresses and control of various physiological processes. Studies have revealed that (p)ppGpp strongly affects the formation and maintenance of several bacterial biofilms. However, the specific regulatory roles of (p)ppGpp in biofilms, especially in the expression of genes related to cell motility and exopolysaccharides (EPSs) production, remain poorly understood. We recently reported two (p)ppGpp synthetase genes relA and spoT from the epizootic pathogen Vibrio alginolyticus. Herein, we found that the (p)ppGpp synthetase genes of V. alginolyticus contributed to biofilm formation at low cell density and biofilm detachment at high cell density, respectively, in polystyrene microtiter plates. Quantitative reverse transcription PCR (qRT-PCR) analysis revealed that the expression levels of both EPSs and motility associated genes were consistent with the development of biofilms. Besides, the (p)ppGpp synthetase gene spoT was found to be closely involved in the regulation of flagellum, smooth/translucent colony morphology and spotty pellicle at the air-liquid interface. Interestingly, pleiotropic phenotypes of ΔrelAΔspoT were similar to that of the rpoN (σ54) deletion mutant. Meanwhile, the absence of (p)ppGpp synthetase genes significantly reduced the expression levels of rpoN at low cell density, suggesting that (p)ppGpp may mediate the formation via positively affecting the alternative sigma factor RpoN. These findings allow us to propose (p)ppGpp as a crucial regulator for biofilm development in V. alginolyticus, in view of the regulatory roles of relA and spoT in cell motility and EPSs production.},
}
@article {pmid35421933,
year = {2022},
author = {Yehia, FAA and Yousef, N and Askoura, M},
title = {Celastrol mitigates staphyloxanthin biosynthesis and biofilm formation in Staphylococcus aureus via targeting key regulators of virulence; in vitro and in vivo approach.},
journal = {BMC microbiology},
volume = {22},
number = {1},
pages = {106},
pmid = {35421933},
issn = {1471-2180},
mesh = {Animals ; Anti-Bacterial Agents/chemistry ; Biofilms ; Mice ; Molecular Docking Simulation ; Pentacyclic Triterpenes ; *Staphylococcal Infections/drug therapy/microbiology ; *Staphylococcus aureus ; Virulence ; Xanthophylls ; },
abstract = {BACKGROUND: Staphylococcus aureus is a leading cause of human infections. The spread of antibiotic-resistant staphylococci has driven the search for novel strategies to supersede antibiotics use. Thus, targeting bacterial virulence rather than viability could be a possible alternative.<br><br>RESULTS: The influence of celastrol on staphyloxanthin (STX) biosynthesis, biofilm formation, antibiotic susceptibility and host pathogenesis in S. aureus has been investigated. Celastrol efficiently reduced STX biosynthesis in S. aureus. Liquid chromatography-mass spectrometry (LC-MS) and molecular docking revealed that celastrol inhibits STX biosynthesis through its effect on CrtM. Quantitative measurement of STX intermediates showed a significant pigment inhibition via interference of celastrol with CrtM and accumulation of its substrate, farnesyl diphosphate. Importantly, celastrol-treated S. aureus was more sensitive to environmental stresses and human blood killing than untreated bacteria. Similarly, inhibition of STX upon celastrol treatment rendered S. aureus more susceptible to membrane targeting antibiotics. In addition to its anti-pigment capability, celastrol exhibits significant anti-biofilm activity against S. aureus as indicated by crystal violet assay and microscopy. Celastrol-treated cells showed deficient exopolysaccharide production and cell hydrophobicity. Moreover, celastrol markedly synergized the action of conventional antibiotics against S. aureus and reduced bacterial pathogenesis in vivo using mice infection model. These findings were further validated using qRT-PCR, demonstrating that celastrol could alter the expression of STX biosynthesis genes as well as biofilm formation related genes and bacterial virulence.<br><br>CONCLUSIONS: Celastrol is a novel anti-virulent agent against S. aureus suggesting, a prospective therapeutic role for celastrol as a multi-targeted anti-pathogenic agent.},
}
@article {pmid35421561,
year = {2022},
author = {Kong, F and Ren, HY and Liu, D and Wang, Z and Nan, J and Ren, NQ and Fu, Q},
title = {Improved decolorization and mineralization of azo dye in an integrated system of anaerobic bioelectrochemical modules and aerobic moving bed biofilm reactor.},
journal = {Bioresource technology},
volume = {353},
number = {},
pages = {127147},
doi = {10.1016/j.biortech.2022.127147},
pmid = {35421561},
issn = {1873-2976},
mesh = {Anaerobiosis ; *Azo Compounds/chemistry ; *Biofilms ; Bioreactors ; Coloring Agents/chemistry ; Waste Disposal, Fluid ; },
abstract = {In this study, a stacked integrated system with anaerobic bioelectrochemical system (BES) and aerobic moving bed biofilm reactor (MBBR) was developed to improve the decolorization and mineralization of azo dye. This stacked BES-MBBR exhibited better performance with acid orange (AO7) decolorization of 96.4 ± 0.6% and chemical oxygen demand (COD) removal of 87.7 ± 4.4%. Contribution of each module in the BES and MBBR stages indicated that BES modules enhanced the pretreatment process in AO7 decolorization, and MBBR played an important role in further removal of COD. The mechanism analysis indicated that the azo bond was cleaved with reductive decolorization at biocathode in the anaerobic BES stages, and then the intermediate products can be further oxidized with COD removal in the aerobic MBBR stage. This work demonstrated that the integrated system with stacked anaerobic BES and aerobic MBBR could provide a promising way for the pretreatment and post-treatment of refractory wastewater.},
}
@article {pmid35420476,
year = {2022},
author = {Honorato, L and de Araujo, JFD and Ellis, CC and Piffer, AC and Pereira, Y and Frases, S and de Sousa Araújo, GR and Pontes, B and Mendes, MT and Pereira, MD and Guimarães, AJ and da Silva, NM and Vargas, G and Joffe, L and Del Poeta, M and Nosanchuk, JD and Zamith-Miranda, D and Dos Reis, FCG and de Oliveira, HC and Rodrigues, ML and de Toledo Martins, S and Alves, LR and Almeida, IC and Nimrichter, L},
title = {Extracellular Vesicles Regulate Biofilm Formation and Yeast-to-Hypha Differentiation in Candida albicans.},
journal = {mBio},
volume = {},
number = {},
pages = {e0030122},
doi = {10.1128/mbio.00301-22},
pmid = {35420476},
issn = {2150-7511},
support = {I01 BX002624/BX/BLRD VA/United States ; IK6 BX005386/BX/BLRD VA/United States ; R01 AI136934/AI/NIAID NIH HHS/United States ; R01 AI116420/AI/NIAID NIH HHS/United States ; R01 AI125770/AI/NIAID NIH HHS/United States ; },
abstract = {In this study, we investigated the influence of fungal extracellular vesicles (EVs) during biofilm formation and morphogenesis in Candida albicans. Using crystal violet staining and scanning electron microscopy (SEM), we demonstrated that C. albicans EVs inhibited biofilm formation in vitro. By time-lapse microscopy and SEM, we showed that C. albicans EV treatment stopped filamentation and promoted pseudohyphae formation with multiple budding sites. The ability of C. albicans EVs to regulate dimorphism was further compared to EVs isolated from different C. albicans strains, Saccharomyces cerevisiae, and Histoplasma capsulatum. C. albicans EVs from distinct strains inhibited yeast-to-hyphae differentiation with morphological changes occurring in less than 4 h. EVs from S. cerevisiae and H. capsulatum modestly reduced morphogenesis, and the effect was evident after 24 h of incubation. The inhibitory activity of C. albicans EVs on phase transition was promoted by a combination of lipid compounds, which were identified by gas chromatography-tandem mass spectrometry analysis as sesquiterpenes, diterpenes, and fatty acids. Remarkably, C. albicans EVs were also able to reverse filamentation. Finally, C. albicans cells treated with C. albicans EVs for 24 h lost their capacity to penetrate agar and were avirulent when inoculated into Galleria mellonella. Our results indicate that fungal EVs can regulate yeast-to-hypha differentiation, thereby inhibiting biofilm formation and attenuating virulence. IMPORTANCE The ability to undergo morphological changes during adaptation to distinct environments is exploited by Candida albicans and has a direct impact on biofilm formation and virulence. Morphogenesis is controlled by a diversity of stimuli, including osmotic stress, pH, starvation, presence of serum, and microbial components, among others. Apart from external inducers, C. albicans also produces autoregulatory substances. Farnesol and tyrosol are examples of quorum-sensing molecules (QSM) released by C. albicans to regulate yeast-to-hypha conversion. Here, we demonstrate that fungal EVs are messengers impacting biofilm formation, morphogenesis, and virulence in C. albicans. The major players exported in C. albicans EVs included sesquiterpenes, diterpenes, and fatty acids. The understanding of how C. albicans cells communicate to regulate physiology and pathogenesis can lead to novel therapeutic tools to combat candidiasis.},
}
@article {pmid35420115,
year = {2022},
author = {Huang, Y and Liu, D and Guo, R and Wang, B and Liu, Z and Guo, Y and Dong, J and Lu, Y},
title = {Magnetic-controlled dandelion-like nanocatalytic swarm for targeted biofilm elimination.},
journal = {Nanoscale},
volume = {14},
number = {17},
pages = {6497-6506},
doi = {10.1039/d2nr00765g},
pmid = {35420115},
issn = {2040-3372},
mesh = {Anti-Bacterial Agents/chemistry/pharmacology ; Bacteria ; Biofilms ; Humans ; *Hydrogen Peroxide/pharmacology ; Magnetic Fields ; *Silicon Dioxide/pharmacology ; },
abstract = {Infections caused by drug-resistant strains pose a serious threat to human health. Most bacterial infections are related to biofilms. The generation of a bacterial biofilm greatly reduces the antibacterial efficiency of antibiotics and some traditional antibacterial drugs, and it is very important to develop antibacterial drugs to replace antibiotics. Here, encouraged by the promising magnetic control technology of micro/nanorobots, the synergistic antibacterial strategy of a dandelion-like magnetically-controlled multifunctional hierarchical magnetic biomimetic nanozyme, Fe3O4@SiO2@dendritic mesoporous silica@small-Fe3O4 nanoparticles (FSDMSsF NPs), was developed to be effective against bacterial biofilms. FSDMSsF NPs showed great magnetic properties and peroxidase-like activities, and could act as catalytic carriers for the production of hydroxyl radicals that are highly toxic to bacteria in a low-concentration H2O2 environment, killing planktonic bacteria. The antibacterial rate of FSDMSsF NPs reached 99.5% at a concentration of 200 μg mL-1. The synergistic antibacterial mechanisms of the mechanical factor and the chemical factor are further discussed. Under time-varying magnetic swarm control, the antibacterial performance of FSDMSsF NPs against bacteria was significantly improved. On this basis, the elimination effect of FSDMSsF NPs on bacterial biofilms is further discussed. The results showed that FSDMSsF NPs could target and eliminate biofilms through complex channels under the control of magnetic fields. In addition, the system could remove biofilms in occlusions by changing the morphology and movement mode of an FSDMSsF NP swarm under magnetic field control. The current work proposes a facile and physical-chemical synergistic strategy for effective antibacterial therapy. FSDMSsF NPs could effectively kill planktonic bacteria and remove stubborn biofilms through magnetic field guidance, achieving thorough antibacterial efficacy, which has great potential in the treatment of drug-resistant bacterial infections.},
}
@article {pmid35419182,
year = {2022},
author = {Waikhom, N and Agarwal, N and Jabin, Z and Anand, A},
title = {Antimicrobial effectiveness of Nano Silver Fluoride Varnish in reducing Streptococcus mutans in saliva and plaque biofilm when compared with Chlorhexidine and Sodium Fluoride Varnishes.},
journal = {Journal of clinical and experimental dentistry},
volume = {14},
number = {4},
pages = {e321-e328},
pmid = {35419182},
issn = {1989-5488},
abstract = {Background: This in vivo study was done to investigate the antimicrobial effectiveness of Nano Silver fluoride, Sodium fluoride and Chlorhexidine when used as a varnish on Streptococcus mutans (S.mutans) in saliva and plaque biofilm.<br><br>Material and Methods: 120 caries free subjects, aged 8-10 years were randomly assigned to four different groups (n=30) - group I: Control, group II: Chlorhexidine varnish (CHX), group III: Sodium fluoride varnish (NaF), group IV: Nano Silver fluoride varnish (NSF). Varnish application was done once at baseline. Saliva and plaque samples were collected at baseline (T0), at the end of 1 month (T1) and 3 months (T3) to evaluate S.mutans levels by culture method, optical density and PCR. OHI-S Index was also recorded for clinical evaluation.<br><br>Results: NSF, CHX and NaF were effective against S.mutans activity. The intragroup comparision of CFU/ml and OD/ml count showed a highly significant reduction from baseline to 3 months for all the 3 varnish groups (p=0.001). PCR result revealed that maximum reduction was seen in NSF and CHX followed by NaF group.<br><br>Conclusions: NSF reduces S.mutans level in both saliva and plaque biofilm and it is more advantageous than CHX and NaF as it has dual properties of acting as an antibacterial as well as a remineralizing agent. Key words:Chlorhexidine, Nano Silver fluoride, Sodium fluoride, S. mutans, varnish.},
}
@article {pmid35418275,
year = {2022},
author = {Vale, GC and Carvalho, GAO and Hoogenkamp, M and Exterkate, R and Crielaard, W and Ten Cate, J},
title = {Effect of high-fluoride dentifrice on root dentine and bacterial composition in a multispecies biofilm model.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-7},
doi = {10.1080/08927014.2022.2065199},
pmid = {35418275},
issn = {1029-2454},
abstract = {The present study evaluated the effect of high-fluoride dentifrice on dentine demineralization and bacterial composition in a multispecies biofilm model in vitro. A seven-organism bacterial consortium was grown on bovine dentine discs in a high-throughput active attachment model. The biofilms were submitted twice per day to the following dentifrices treatments: 5,000 ppm F, 1,100 ppm F, with placebo as a negative control. After 5 days of biofilm growth, dentine samples were assessed by transversal microradiography, the biofilm was collected for bacterial counts and the pH of the media was determined. Lower integrated mineral loss values were observed when 5,000 ppm F-treatment was used compared to the other treatments. Overall microbiological counts decreased with increasing F-concentration as well the pH of the media throughout the experiment. The 5,000 ppm F-treatment caused a shift in microbial composition and reduced dentine demineralization in the in-vitro experimental model.},
}
@article {pmid35418164,
year = {2022},
author = {Lin, Y and Xu, X and Maróti, G and Strube, ML and Kovács, ÁT},
title = {Adaptation and phenotypic diversification of Bacillus thuringiensis biofilm are accompanied by fuzzy spreader morphotypes.},
journal = {NPJ biofilms and microbiomes},
volume = {8},
number = {1},
pages = {27},
pmid = {35418164},
issn = {2055-5008},
support = {NNFOC0055625//Novo Nordisk Fonden (Novo Nordisk Foundation)/ ; DNRF137//Danmarks Grundforskningsfond (Danish National Research Foundation)/ ; },
mesh = {Bacillus cereus ; *Bacillus thuringiensis/genetics ; Biofilms ; DNA Transposable Elements ; },
abstract = {Bacillus cereus group (Bacillus cereus sensu lato) has a diverse ecology, including various species that produce biofilms on abiotic and biotic surfaces. While genetic and morphological diversification enables the adaptation of multicellular communities, this area remains largely unknown in the Bacillus cereus group. In this work, we dissected the experimental evolution of Bacillus thuringiensis 407 Cry- during continuous recolonization of plastic beads. We observed the evolution of a distinct colony morphotype that we named fuzzy spreader (FS) variant. Most multicellular traits of the FS variant displayed higher competitive ability versus the ancestral strain, suggesting an important role for diversification in the adaptation of B. thuringiensis to the biofilm lifestyle. Further genetic characterization of FS variant revealed the disruption of a guanylyltransferase gene by an insertion sequence (IS) element, which could be similarly observed in the genome of a natural isolate. The evolved FS and the deletion mutant in the guanylyltransferase gene (Bt407ΔrfbM) displayed similarly altered aggregation and hydrophobicity compared to the ancestor strain, suggesting that the adaptation process highly depends on the physical adhesive forces.},
}
@article {pmid35417624,
year = {2022},
author = {Tlais, AZA and Polo, A and Filannino, P and Cantatore, V and Gobbetti, M and Di Cagno, R},
title = {Biofilm formation as an extra gear for Apilactobacillus kunkeei to counter the threat of agrochemicals in honeybee crop.},
journal = {Microbial biotechnology},
volume = {},
number = {},
pages = {},
doi = {10.1111/1751-7915.14051},
pmid = {35417624},
issn = {1751-7915},
support = {//Faculty of Science and Technology of the Free University of Bozen-Bolzano/ ; },
abstract = {The alteration of a eubiosis status in honeybees' gut microbiota is directly linked to the occurrence of diseases, and likely to the honeybees decline. Since fructophilic lactobacilli were suggested as symbionts for honeybees, we mechanistically investigated their behaviour under the exposure to agrochemicals (Roundup, Mediator and Reldan containing glyphosate, imidacloprid and chlorpyrifos-methyl as active ingredients respectively) and plant secondary metabolites (nicotine and p-coumaric acid) ingested by honeybees as part of their diet. The effects of exposure to agrochemicals and plant secondary metabolites were assessed both on planktonic cells and sessile communities of three biofilm-forming strains of Apilactobacillus kunkeei. We identified the high sensitivity of A. kunkeei planktonic cells to Roundup and Reldan, while cells embedded in mature biofilms had increased resistance to the same agrochemicals. However, agrochemicals still exerted a substantial inhibitory/control effect if the exposure was during the preliminary steps of biofilm formation. The level of susceptibility resulted to be strain-specific. Exopolysaccharides resulted in the main component of extracellular polymeric matrix (ECM) in biofilm, but the exposure to Roundup caused a change in ECM production and composition. Nicotine and p-coumaric acid had a growth-promoting effect in sessile communities, although no effect was found on planktonic growth.},
}
@article {pmid35416708,
year = {2022},
author = {Landlinger, C and Oberbauer, V and Podpera Tisakova, L and Schwebs, T and Berdaguer, R and Van Simaey, L and Vaneechoutte, M and Corsini, L},
title = {Preclinical Data on the Gardnerella-Specific Endolysin PM-477 Indicate Its Potential to Improve the Treatment of Bacterial Vaginosis through Enhanced Biofilm Removal and Avoidance of Resistance.},
journal = {Antimicrobial agents and chemotherapy},
volume = {66},
number = {5},
pages = {e0231921},
doi = {10.1128/aac.02319-21},
pmid = {35416708},
issn = {1098-6596},
support = {//Austrian FFG/ ; },
abstract = {Antibiotics are the mainstay of therapy for bacterial vaginosis (BV). However, the rate of treatment failure in patients with recurrent BV is about 50%. Herein, we investigated potential mechanisms of therapy failure, including the propensity of resistance formation and biofilm activity of metronidazole (MDZ), clindamycin (CLI), and PM-477, a novel investigational candidate that is a genetically engineered endolysin with specificity for bacteria of the genus Gardnerella. Determination of the MIC indicated that 60% of a panel of 22 Gardnerella isolates of four different species were resistant to MDZ, while all strains were highly susceptible to CLI and to the endolysin PM-477. Six strains, all of which were initially susceptible to MDZ, were passaged with MDZ or its more potent hydroxy metabolite. All of them generated full resistance after 5 to 10 passages, resulting in MICs of >512 μg/mL. In contrast, only a mild increase in MIC was found for PM-477. There was also no cross-resistance formation, as MDZ-resistant Gardnerella strains remained highly susceptible to PM-477, both in suspension and in preformed biofilms. Strains that were resistant to MDZ in suspension were also tolerant to MDZ at >2,048 μg/mL when growing as biofilm. All strains were susceptible to PM-477 when grown as preformed biofilms, at minimum biofilm eradication concentrations (MBECs) in the range of 1 to 4 μg/mL. Surprisingly, the MBEC of CLI was >512 μg/mL for 7 out of 9 tested Gardnerella strains, all of which were susceptible to CLI when growing in suspension. The observed challenges of MDZ and CLI due to resistance formation and ineffectiveness on biofilm, respectively, could be one explanation for the frequent treatment failures in uncomplicated or recurrent BV. Therefore, the high efficacy of PM-477 in eliminating Gardnerella in in vitro biofilms, as well as its high resilience to resistance formation, makes PM-477 a promising potential alternative for the treatment of bacterial vaginosis, especially in patients with frequent recurrence.},
}
@article {pmid35416687,
year = {2022},
author = {Sass, A and Vandenbussche, I and Bellich, B and Cescutti, P and Coenye, T},
title = {Pellicle Biofilm Formation in Burkholderia cenocepacia J2315 is Epigenetically Regulated through WspH, a Hybrid Two-Component System Kinase-Response Regulator.},
journal = {Journal of bacteriology},
volume = {204},
number = {5},
pages = {e0001722},
doi = {10.1128/jb.00017-22},
pmid = {35416687},
issn = {1098-5530},
support = {BOFDOC2016001301//UGent | Bijzonder Onderzoeksfonds UGent (BOF)/ ; },
abstract = {The chemosensory signal transduction system Wsp regulates biofilm formation and related phenotypes by influencing cyclic-di-GMP (c-di-GMP) levels in bacterial cells. This is typically achieved by activation of the diguanylate cyclase WspR, through phosphorylation of its phosphoreceiver domain. The Wsp system of Burkholderia cenocepacia J2315 is in one operon with the hybrid response regulator/histidine kinase wspH, but lacks the diguanylate cyclase wspR which is located in a different operon. The expression of wspH, the first gene in the B. cenocepacia Wsp operon as well as pellicle biofilm formation are epigenetically regulated in B. cenocepacia J2315. To investigate whether WspH regulates pellicle biofilm formation, several mutants with altered expression of wspH were constructed. Mutants with increased expression of wspH showed accelerated pellicle biofilm formation, reduced swimming motility and increased c-di-GMP levels. This was independent of WspR phosphorylation, showing that WspR is not the cognate response receiver for histidine kinase WspH. IMPORTANCE Biofilms are surface-attached or suspended aggregates of cells, that are problematic in the context of bacterial infections, as they provide protection from antibiotic treatment. Burkholderia cenocepacia can colonize the lung of immunocompromised patients and forms biofilms that increase its recalcitrance to antibiotic treatment. Pellicles are biofilms which form at an air-liquid interface to take advantage of the higher oxygen concentrations in this environment. How quickly pellicles are formed is crucial for the fitness of obligate aerobic bacteria such as B. cenocepacia. Cyclic-di-GMP (c-di-GMP) levels determine the transition between planktonic and biofilm lifestyle, and WspH controls c-di-GMP production. WspH is therefore important for the fitness of B. cenocepacia in environments with gradients in oxygen concentration, such as the human lung.},
}
@article {pmid35416682,
year = {2022},
author = {Wu, J and Jiang, X and Yang, Q and Zhang, Y and Wang, C and Huang, R},
title = {Inhibition of Streptococcus mutans Biofilm Formation by the Joint Action of Oxyresveratrol and Lactobacillus casei.},
journal = {Applied and environmental microbiology},
volume = {88},
number = {9},
pages = {e0243621},
pmid = {35416682},
issn = {1098-5336},
support = {31800114//National Natural Science Foundation of China (NSFC)/ ; },
mesh = {Biofilms ; *Dental Caries ; *Dental Plaque ; Glucans ; Humans ; *Lactobacillus casei ; Plant Extracts ; Polyphenols/pharmacology ; Stilbenes ; Streptococcus mutans/genetics ; Water/pharmacology ; },
abstract = {Microbial dysbiosis in dental plaque contributes to the occurrence of dental caries, to which Streptococcus mutans is a major contributor. Lactobacillus casei can be used as probiotic therapy to treat caries by replacing S. mutans within the dental plaque. However, the effects of probiotic treatment are not always stable. Oxyresveratrol (ORV), a plant-derived polyphenol, displays opposite effects in that it inhibits cariogenic and promotes commensal bacteria. Thus, the objectives of this study are to investigate the effects of ORV on bacterial proportions in S. mutans-L. casei biofilm and to elucidate how ORV weakens the competitiveness of S. mutans. Quantitative real-time PCR confirms a decreased S. mutans-L. casei ratio in dual-species biofilm by action of ORV. The culture supernatant of L. casei after being incubated with ORV (ORVLC) is prepared to explore the joint action of ORV and L. casei. ORVLC displays the strongest anti-biofilm effect against S. mutans when compared with the effects of L. casei supernatant or ORV alone. As a result of this treatment, both exopolysaccharides and bacteria contents in the biofilm are greatly reduced. The biofilm is transformed from water-insoluble glucan-dominant to water-soluble glucan-dominant by ORVLC through the modulation of the glycometabolism-related genes of S. mutans. As for the interactions between ORV and L. casei, ORV promotes L. casei to produce acetic acid, which provides L. casei with a competitive advantage against S. mutans. Taken together, ORV may be very suitable as an adjuvant medicine for probiotic therapy in the control of dental caries. IMPORTANCE The homeostatic imbalance in dental plaque associated with a sharp increase in the number of cariogenic bacteria such as Streptococcus mutans is critical for the occurrence and development of caries. Probiotic therapy can restore ecological balance by replacing cariogenic pathogens with probiotics. The current study innovatively finds that oxyresveratrol, a natural polyphenol, can provide probiotic Lactobacillus casei with competitive dominance in its dual-species biofilm with S. mutans. The joint action of oxyresveratrol and L. casei strongly inhibits the biofilm formation of S. mutans. Additionally, oxyresveratrol promotes L. casei to produce acetic acid, which facilitates L. casei to compete with S. mutans. Through the effects of these two mechanisms, oxyresveratrol leads to a significantly decreased S. mutans-L. casei ratio in their dual-species biofilm. Thus, oxyresveratrol is speculated to be an ideal medicine for the prevention and treatment of caries by regulating oral flora balance.},
}
@article {pmid35414993,
year = {2022},
author = {Choi, H and Zaki, FR and Monroy, GL and Won, J and Boppart, SA},
title = {Imaging and characterization of transitions in biofilm morphology via anomalous diffusion following environmental perturbation.},
journal = {Biomedical optics express},
volume = {13},
number = {3},
pages = {1654-1670},
pmid = {35414993},
issn = {2156-7085},
abstract = {Microorganisms form macroscopic structures for the purpose of environmental adaptation. Sudden environmental perturbations induce dynamics that cause bacterial biofilm morphology to transit to another equilibrium state, thought to be related to anomalous diffusion processes. Here, detecting the super-diffusion characteristics would offer a long-sought goal for a rapid detection method of biofilm phenotypes based on their dynamics, such as growth or dispersal. In this paper, phase-sensitive Doppler optical coherence tomography (OCT) and dynamic light scattering (DLS) are combined to demonstrate wide field-of-view and label-free internal dynamic imaging of biofilms. The probability density functions (PDFs) of phase displacement of the backscattered light and the dynamic characteristics of the PDFs are estimated by a simplified mixed Cauchy and Gaussian model. This model can quantify the super-diffusion state and estimate the dynamic characteristics and macroscopic responses in biofilms that may further describe dispersion and growth in biofilm models.},
}
@article {pmid35414488,
year = {2022},
author = {Narasimman, M and Ory, J and Bartra, SS and Plano, GV and Ramasamy, R},
title = {Evaluation of Bacteria in a Novel In Vitro Biofilm Model of Penile Prosthesis.},
journal = {The journal of sexual medicine},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.jsxm.2022.03.602},
pmid = {35414488},
issn = {1743-6109},
abstract = {BACKGROUND: Delayed infection, thought to be due to gradual biofilm formation, remains a feared complication after inflatable penile prosthesis (IPP) insertion. Understanding and preventing biofilm formation is necessary to prevent infections.<br><br>AIM: To develop an in vitro model and compare growth of biofilm by different bacteria on IPPs and evaluate the anti-infective efficacy of the Coloplast Titan and AMS 700 InhibiZone.<br><br>METHODS: Sterile IPPs (Coloplast) were cut into rings and incubated with S. epidermidis, S. aureus, P. aeruginosa, A. baumannii, or K. pneumoniae cultures in tryptic soy broth (TSB) (4 hour) to ensure adequate bacteria attachment, and then in only TSB (120 hours) to allow for biofilm formation. Rings were fixed with ethanol and biofilm measured by spectrophotometer (OD570) after crystal violet staining. This methodology was repeated for S. epidermidis and P. aeruginosa with Coloplast rings dipped in 10 ml of a 10 mg/ml Rifampin, 1 mg/ml Gentamicin, and deionized water solution and undipped AMS InhibiZone rings. Crystal violet assay (OD570) was repeated after incubation within bacteria (2 hour), and then only TSB (120 hours).<br><br>OUTCOMES: The primary outcome of the study was OD570 readings, indirectly measuring biofilm mass on implant rings.<br><br>RESULTS: S. epidermidis, S. aureus, A. baumannii, P. aeruginosa, and K. pneumoniae all formed significant biofilm. P. aeruginosa showed the strongest predilection to grow biofilm on IPPs. P. aeruginosa also formed significant biofilm on antibiotic-treated Coloplast and AMS rings, while S. epidermidis was inhibited. No significant difference was found in biofilm inhibition between the implants.<br><br>CLINICAL TRANSLATION: Our findings suggest gram-negative bacteria may form biofilm more proficiently and quickly on IPPs than gram-positive organisms. Commonly used antibiotic treatments on IPPs may be effective against S. epidermidis but not against P. aeruginosa biofilm formation.<br><br>STRENGTHS &amp; LIMITATIONS: This is the first study comparing biofilm formation by different bacteria organisms on IPPs and the inhibitive ability of Coloplast and AMS implants against biofilm formation. Clinical data on organisms responsible for infected IPPs is needed to determine the clinical relevance of our findings.<br><br>CONCLUSION: Our novel in vitro model of biofilm formation of IPPs evaluated the effect of a gentamicin/rifampin antibiotic dip on Coloplast Titan implants and the anti-infective capacity of the minocycline/rifampin precoated AMS 700 InhibiZone against S. epidermidis and P. aeruginosa. P. aeruginosa was able to grow on both antibiotic-treated implants, with no significant difference, and should continue to be a specific target of investigation to reduce delayed post-operative IPP infections. Narasimman M, Ory J, Bartra SS, et al. Evaluation of Bacteria in a Novel In Vitro Biofilm Model of Penile Prosthesis. J Sex Med 2022;XX:XXX-XXX.},
}
@article {pmid35411160,
year = {2022},
author = {Hou, C and Yin, F and Wang, S and Zhao, A and Li, Y and Liu, Y},
title = {Helicobacter pylori Biofilm-Related Drug Resistance and New Developments in Its Anti-Biofilm Agents.},
journal = {Infection and drug resistance},
volume = {15},
number = {},
pages = {1561-1571},
pmid = {35411160},
issn = {1178-6973},
abstract = {Helicobacter pylori is one of the most common pathogenic bacterium worldwide, infecting about 50% of the world's population. It is a major cause of several upper gastrointestinal diseases, including peptic ulcers and gastric cancer. The emergence of H. pylori resistance to antibiotics has been a major clinical challenge in the field of gastroenterology. In the course of H. pylori infection, some bacteria invade the gastric epithelium and are encapsulated into a self-produced matrix to form biofilms that protect the bacteria from external threats. Bacteria with biofilm structures can be up to 1000 times more resistant to antibiotics than planktonic bacteria. This implies that targeting biofilms might be an effective strategy to alleviate H. pylori drug resistance. Therefore, it is important to develop drugs that can eliminate or disperse biofilms. In recent years, anti-biofilm agents have been investigated as alternative or complementary therapies to antibiotics to reduce the rate of drug resistance. This article discusses the formation of H. pylori biofilms, the relationship between biofilms and drug resistance in H. pylori, and the recent developments in the research of anti-biofilm agents targeting H. pylori drug resistance.},
}
@article {pmid35410595,
year = {2022},
author = {Bharti, S and Zakir, F and Mirza, MA and Aggarwal, G},
title = {Antifungal biofilm strategies: a less explored area in wound management.},
journal = {Current pharmaceutical biotechnology},
volume = {},
number = {},
pages = {},
doi = {10.2174/1389201023666220411100214},
pmid = {35410595},
issn = {1873-4316},
abstract = {Background- The treatment of wound associated infections has always remained a challenge for clinicians with the major deterring factor being microbial biofilms, majorly bacterial or fungal. Biofilm infections are becoming a global concern owing to resistance against antimicrobials. Fungal biofilms are formed by a wide variety of fungal pathogens namely Candida sp., Aspergillus fumigates, Trichosporon sp., Saccharomyces cerevisiae, Cryptococcus neoformans, among others. The rising cases of fungal biofilm resistance add to the burden of wound care. Additionally, with increase in the number of surgical procedures, transplantation and the exponential use of medical devices, fungal bioburden is on the rise. Objectives- The review discusses the methods of biofilm formation and the resistance mechanisms against conventional treatments. The potential of novel delivery strategies and the mechanisms involved therein are highlighted. Further, the prospects of nanotechnology based medical devices to combat fungal biofilm resistance have also been explored. Some of the clinical trials and up-to-date patent technologies to eradicate the biofilms are also mentioned. Conclusion- Due to the many challenges faced in preventing/eradicating biofilms, only a handful of approaches have been able to make it to the market. Fungal biofilms are a fragmentary area which needs further exploration.},
}
@article {pmid35410114,
year = {2022},
author = {Liu, K and Tan, S and Ye, W and Hou, L and Fang, B},
title = {Low-concentration iron promotes Klebsiella pneumoniae biofilm formation by suppressing succinic acid.},
journal = {BMC microbiology},
volume = {22},
number = {1},
pages = {95},
pmid = {35410114},
issn = {1471-2180},
mesh = {Anti-Bacterial Agents/pharmacology ; Biofilms ; Iron/pharmacology ; *Klebsiella pneumoniae ; *Succinic Acid/pharmacology ; },
abstract = {BACKGROUND: Klebsiella pneumoniae is widely distributed in water and plays a major role in both human and poultry infections. Many K. pneumoniae strains form biofilms on various surfaces, enhancing their pathogenicity and resistance to antibiotics. The water supply pipeline of chicken farms has become a hotbed for the growth of K pneumoniae biofilm because of its humid environment, and because the chicken drinking water pipeline is thin, it is easily blocked by the biofilm, and the diffused cells can cause repeated and persistent infections. Iron is vital to the growth of microorganisms and the formation of biofilms. Therefore, the aim of this study was to examine the effects of iron on K. pneumoniae biofilm formation and any associated metabolic changes to provide a rationale for reducing the formation of biofilms.<br><br>RESULTS: Biofilm formation was enhanced to the greatest extent by the presence of 0.16 mM FeCl2, producing a denser structure under electron microscopy. The number of biofilm-forming and planktonic bacteria did not change, but protein and polysaccharide concentrations in the bacterial extracellular polymeric substances (EPS) were significantly increased by iron supplementation. To clarify this mechanism, intracellular metabolomic analysis was carried out, showing that the differential, down-regulated metabolites included succinic acid. The addition of 1.7 mM succinic acid counteracted the biofilm-forming effect of iron, with no bactericidal side effects.<br><br>CONCLUSION: This study demonstrates the importance of succinic acid and iron in K. pneumoniae biofilms, and provides insight into the formation of K. pneumoniae biofilms and direction for the development of new antibacterial agents.},
}
@article {pmid35409199,
year = {2022},
author = {Li, QC and Wang, B and Zeng, YH and Cai, ZH and Zhou, J},
title = {The Microbial Mechanisms of a Novel Photosensitive Material (Treated Rape Pollen) in Anti-Biofilm Process under Marine Environment.},
journal = {International journal of molecular sciences},
volume = {23},
number = {7},
pages = {},
pmid = {35409199},
issn = {1422-0067},
support = {41976126//National Natural Science Foundation of China/ ; 2020B1515120012//Guangdong Basic and Applied Basic Research Foundation/ ; },
mesh = {*Biofilms ; *Biofouling/prevention &amp; control ; Oxidants/pharmacology ; Pollen ; Seawater/microbiology ; },
abstract = {Marine biofouling is a worldwide problem in coastal areas and affects the maritime industry primarily by attachment of fouling organisms to solid immersed surfaces. Biofilm formation by microbes is the main cause of biofouling. Currently, application of antibacterial materials is an important strategy for preventing bacterial colonization and biofilm formation. A natural three-dimensional carbon skeleton material, TRP (treated rape pollen), attracted our attention owing to its visible-light-driven photocatalytic disinfection property. Based on this, we hypothesized that TRP, which is eco-friendly, would show antifouling performance and could be used for marine antifouling. We then assessed its physiochemical characteristics, oxidant potential, and antifouling ability. The results showed that TRP had excellent photosensitivity and oxidant ability, as well as strong anti-bacterial colonization capability under light-driven conditions. Confocal laser scanning microscopy showed that TRP could disperse pre-established biofilms on stainless steel surfaces in natural seawater. The biodiversity and taxonomic composition of biofilms were significantly altered by TRP (p < 0.05). Moreover, metagenomics analysis showed that functional classes involved in the antioxidant system, environmental stress, glucose-lipid metabolism, and membrane-associated functions were changed after TRP exposure. Co-occurrence model analysis further revealed that TRP markedly increased the complexity of the biofilm microbial network under light irradiation. Taken together, these results demonstrate that TRP with light irradiation can inhibit bacterial colonization and prevent initial biofilm formation. Thus, TRP is a potential nature-based green material for marine antifouling.},
}
@article {pmid35408683,
year = {2022},
author = {Neumann, N and Honke, M and Povydysh, M and Guenther, S and Schulze, C},
title = {Evaluating Tannins and Flavonoids from Traditionally Used Medicinal Plants with Biofilm Inhibitory Effects against MRGN E. coli.},
journal = {Molecules (Basel, Switzerland)},
volume = {27},
number = {7},
pages = {},
pmid = {35408683},
issn = {1420-3049},
support = {393148499//Deutsche Forschungsgemeinschaft/ ; },
mesh = {Anti-Bacterial Agents/pharmacology ; *Anti-Infective Agents/pharmacology ; Biofilms ; Escherichia coli ; Flavonoids/pharmacology ; Microbial Sensitivity Tests ; Plant Extracts/pharmacology ; *Plants, Medicinal ; Tannins/analysis/pharmacology ; },
abstract = {In the search for alternative treatment options for infections with multi-resistant germs, traditionally used medicinal plants are currently being examined more intensively. In this study, the antimicrobial and anti-biofilm activities of 14 herbal drugs were investigated. Nine of the tested drugs were traditionally used in Europe for treatment of local infections. For comparison, another five drugs monographed in the European Pharmacopoeia were used. Additionally, the total tannin and flavonoid contents of all tested drugs were analyzed. HPLC fingerprints were recorded to obtain further insights into the components of the extracts. The aim of the study was to identify herbal drugs that might be useable for treatment of infectious diseases, even with multidrug resistant E. coli, and to correlate the antimicrobial activity with the total content of tannins and flavonoids. The agar diffusion test and anti-biofilm assay were used to evaluate the antimicrobial potential of different extracts from the plants. Colorimetric methods (from European Pharmacopeia) were used for determination of total tannins and flavonoids. The direct antimicrobial activity of most of the tested extracts was low to moderate. The anti-biofilm activity was found to be down to 10 µg mL-1 for some extracts. Tannin contents between 2.2% and 10.4% of dry weight and total flavonoid contents between 0.1% and 1.6% were found. Correlation analysis indicates that the antimicrobial and the anti-biofilm activity is significantly (p < 0.05) dependent on tannin content, but not on flavonoid content. The data analysis revealed that tannin-rich herbal drugs inhibit pathogens in different ways. Thus, some of the tested herbal drugs might be useable for local infections with multi-resistant biofilm-forming pathogens. For some of the tested drugs, this is the first report about anti-biofilm activity, as well as total tannin and flavonoid content.},
}
@article {pmid35407064,
year = {2022},
author = {Roy, PK and Song, MG and Park, SY},
title = {Impact of Quercetin against Salmonella Typhimurium Biofilm Formation on Food-Contact Surfaces and Molecular Mechanism Pattern.},
journal = {Foods (Basel, Switzerland)},
volume = {11},
number = {7},
pages = {},
pmid = {35407064},
issn = {2304-8158},
support = {2021R1I1A3A04037468//National Research Foundation of Korea/ ; },
abstract = {Quercetin is an active nutraceutical element that is found in a variety of foods, vegetables, fruits, and other products. Due to its antioxidant properties, quercetin is a flexible functional food that has broad protective effects against a wide range of infectious and degenerative disorders. As a result, research is required on food-contact surfaces (rubber (R) and hand gloves (HG)) that can lead to cross-contamination. In this investigation, the inhibitory effects of quercetin, an antioxidant and antibacterial molecule, were investigated at sub-MIC (125; 1/2, 62.5; 1/4, and 31.25; 1/8 MIC, μg/mL) against Salmonella Typhimurium on surfaces. When quercetin (0-125 μg/mL) was observed on R and HG surfaces, the inhibitory effects were 0.09-2.49 and 0.20-2.43 log CFU/cm2, respectively (p < 0.05). The results were confirmed by field emission scanning electron microscopy (FE-SEM), because quercetin inhibited the biofilms by disturbing cell-to-cell connections and inducing cell lysis, resulting in the loss of normal cell morphology, and the motility (swimming and swarming) was significantly different at 1/4 and 1/2 MIC compared to the control. Quercetin significantly (p < 0.05) suppressed the expression levels of virulence and stress response (rpoS, avrA, and hilA) and quorum-sensing (luxS) genes. Our findings imply that plant-derived quercetin could be used as an antibiofilm agent in the food industry to prevent S. Typhimurium biofilm formation.},
}
@article {pmid35407047,
year = {2022},
author = {Madani, A and Esfandiari, Z and Shoaei, P and Ataei, B},
title = {Evaluation of Virulence Factors, Antibiotic Resistance, and Biofilm Formation of Escherichia coli Isolated from Milk and Dairy Products in Isfahan, Iran.},
journal = {Foods (Basel, Switzerland)},
volume = {11},
number = {7},
pages = {},
pmid = {35407047},
issn = {2304-8158},
abstract = {Diarrheagenic E. coli (DEC) strains are important causes of gastrointestinal diseases worldwide, especially in developing countries. This study aimed to investigate the presence, antibiotic resistance, and potential biofilm formation in dairy products in Isfahan, Iran. A total of 200 samples, including traditional and pasteurized dairy products, were analyzed. In 200 samples, 54 E. coli isolates, including (48/110) and (6/90) positive samples of traditional and pasteurized dairy products, were detected. Furthermore, pathogenic strains were isolated from 30% of traditional dairy products and 5.55% of pasteurized dairy products. Most isolates were classified as enteropathogenic E. coli (EPEC). Moreover, antibiotic resistance was evaluated using the disk diffusion method for pathogenic E. coli. Overall, 73.68% of contaminated samples by pathogenic strains were resistant to at least one antibiotic. The highest resistance was observed against streptomycin (57.9%), followed by tetracycline (50%). Additionally, all isolates were sensitive to amikacin. For evaluating biofilm formation, the violet crystal assay was applied on a polystyrene microplate well for pathogenic isolates. In total, 68.42% of isolates were able to form biofilms. The presence of E. coli in dairy products indicates potential health risks for Iranian consumers. Serious measures are needed to control and prevent the spread of this pathogen.},
}
@article {pmid35406207,
year = {2022},
author = {Josic, U and Mazzitelli, C and Maravic, T and Fidler, A and Breschi, L and Mazzoni, A},
title = {Biofilm in Endodontics: In Vitro Cultivation Possibilities, Sonic-, Ultrasonic- and Laser-Assisted Removal Techniques and Evaluation of the Cleaning Efficacy.},
journal = {Polymers},
volume = {14},
number = {7},
pages = {},
pmid = {35406207},
issn = {2073-4360},
abstract = {Incomplete and inadequate removal of endodontic biofilm during root canal treatment often leads to the clinical failure. Over the past decade, biofilm eradication techniques, such as sonication of irrigant solutions, ultrasonic and laser devices have been investigated in laboratory settings. This review aimed to give an overview of endodontic biofilm cultivation methods described in papers which investigated sonic-, ultrasonic- and Er:Yag laser-assisted biofilm removal techniques. Furthermore, the effectiveness of these removal techniques was discussed, as well as methods used for the evaluation of the cleaning efficacy. In general, laser assisted agitation, as well as ultrasonic and sonic activation of the irrigants provide a more efficient biofilm removal compared to conventional irrigation conducted by syringe/needle. The choice of irrigant is an important factor for reducing the bacterial contamination inside the root canal, with water and saline being the least effective. Due to heterogeneity in methods among the reviewed studies, it is difficult to compare sonic-, ultrasonic- and Er:Yag laser-assisted techniques among each other and give recommendations for the most efficient method in biofilm removal. Future studies should standardize the methodology regarding biofilm cultivation and cleaning methods, root canals with complex morphology should be introduced in research, with the aim of simulating the clinical scenario more closely.},
}
@article {pmid35405293,
year = {2022},
author = {de Melo Costa, D and Castillo, R and Vickery, K and Ferreira Veiga Tipple, A and de Oliveira Lopes, LK and Hu, H},
title = {Hinged surgical instruments: efficacy of double manual cleaning versus automated cleaning on biofilm removal.},
journal = {The Journal of hospital infection},
volume = {124},
number = {},
pages = {67-71},
doi = {10.1016/j.jhin.2022.03.011},
pmid = {35405293},
issn = {1532-2939},
abstract = {The efficacy of double manual cleaning (DMC) with enzymatic detergent followed by alkaline detergent on biofilm removal on hinged surgical instruments was compared to automated cleaning. Biofilm-covered haemostatic forceps were divided into four groups: positive control (soaked in sterile water); DMC; DMC plus extra brushing of the inner hinge; and automated cleaning. All DMC, DMC plus brushing the hinge, and automated cleaning significantly (P < 0.001) reduced 94.8%, 99.8%, and 100% viable bacteria and 82.3%, 93.8%, and 95.1% residual protein, respectively, compared to positive control. DMC instruments had significantly more viable bacteria (P < 0.05) and residual protein (P < 0.01) than those in instruments subjected to DMC with hinge brushing and automated cleaning. However, there was no significant difference in residual protein between DMC with hinge brushing and automated cleaning. In sterilizing service units with no access to automated cleaning equipment, it is important to brush the inner hinge during manual cleaning, and DMC plus brushing the inner hinge could be considered a viable alternative for cleaning hinged surgical instruments.},
}
@article {pmid35405192,
year = {2022},
author = {Chyoshi, B and Gomes Coelho, LH and García, J and Subtil, EL},
title = {Fate and removal of emerging contaminants in anaerobic fluidized membrane bioreactor filled with thermoplastic gel as biofilm support.},
journal = {Chemosphere},
volume = {300},
number = {},
pages = {134557},
doi = {10.1016/j.chemosphere.2022.134557},
pmid = {35405192},
issn = {1879-1298},
abstract = {The Anaerobic Fluidized Membrane Bioreactor (AnFMBR) is a membrane-based hybrid technology that can overcome the limitations of conventional anaerobic sewage treatment. Although previous studies have demonstrated excellent performance in the removal of conventional organic pollutants, further research into the removal paths of emerging contaminants (ECs) under various operating conditions is required for proper design and development of the AnFMBR technology. Regarding this, the fate of four ECs in a lab-scale AnFMBR filled with thermoplastic gel for biofilm growth was investigated under various Hydraulic Retention Time (HRT) conditions. When the HRT was 13 h, diclofenac and 17β-estradiol were efficiently removed at 93% and 72% respectively. Even after an HRT reduction to 6.5 h, the system was still able to maintain high ECs removals (74% for diclofenac and 69% for 17β-estradiol). However, irrespective of HRT operational condition, smaller removals of 17a-ethinylestradiol (37-52%) were observed, while only marginal removals of amoxicillin were achieved (5-29%). Biotransformation was attributed as the main route for ECs removal. The results obtained in this study indicate that the membrane-based hybrid AnFMBR can be used to treat the target ECs without influence on anaerobic process. The technology had better removal efficiency for diclofenac and 17β-estradiol. However, the AnFMBR system exhibits high variability in EC removal and low capacity for amoxicillin removal, implying that a combination of other processes is still required to properly avoid the release of these contaminants into the environment.},
}
@article {pmid35402433,
year = {2022},
author = {Roy, S and Chowdhury, G and Mukhopadhyay, AK and Dutta, S and Basu, S},
title = {Convergence of Biofilm Formation and Antibiotic Resistance in Acinetobacter baumannii Infection.},
journal = {Frontiers in medicine},
volume = {9},
number = {},
pages = {793615},
pmid = {35402433},
issn = {2296-858X},
abstract = {Acinetobacter baumannii (A. baumannii) is a leading cause of nosocomial infections as this pathogen has certain attributes that facilitate the subversion of natural defenses of the human body. A. baumannii acquires antibiotic resistance determinants easily and can thrive on both biotic and abiotic surfaces. Different resistance mechanisms or determinants, both transmissible and non-transmissible, have aided in this victory over antibiotics. In addition, the propensity to form biofilms (communities of organism attached to a surface) allows the organism to persist in hospitals on various medical surfaces (cardiac valves, artificial joints, catheters, endotracheal tubes, and ventilators) and also evade antibiotics simply by shielding the bacteria and increasing its ability to acquire foreign genetic material through lateral gene transfer. The biofilm formation rate in A. baumannii is higher than in other species. Recent research has shown how A. baumannii biofilm-forming capacity exerts its effect on resistance phenotypes, development of resistome, and dissemination of resistance genes within biofilms by conjugation or transformation, thereby making biofilm a hotspot for genetic exchange. Various genes control the formation of A. baumannii biofilms and a beneficial relationship between biofilm formation and "antimicrobial resistance" (AMR) exists in the organism. This review discusses these various attributes of the organism that act independently or synergistically to cause hospital infections. Evolution of AMR in A. baumannii, resistance mechanisms including both transmissible (hydrolyzing enzymes) and non-transmissible (efflux pumps and chromosomal mutations) are presented. Intrinsic factors [biofilm-associated protein, outer membrane protein A, chaperon-usher pilus, iron uptake mechanism, poly-β-(1, 6)-N-acetyl glucosamine, BfmS/BfmR two-component system, PER-1, quorum sensing] involved in biofilm production, extrinsic factors (surface property, growth temperature, growth medium) associated with the process, the impact of biofilms on high antimicrobial tolerance and regulation of the process, gene transfer within the biofilm, are elaborated. The infections associated with colonization of A. baumannii on medical devices are discussed. Each important device-related infection is dealt with and both adult and pediatric studies are separately mentioned. Furthermore, the strategies of preventing A. baumannii biofilms with antibiotic combinations, quorum sensing quenchers, natural products, efflux pump inhibitors, antimicrobial peptides, nanoparticles, and phage therapy are enumerated.},
}
@article {pmid35402304,
year = {2022},
author = {Krzyżek, P and Migdał, P and Grande, R and Gościniak, G},
title = {Biofilm Formation of Helicobacter pylori in Both Static and Microfluidic Conditions Is Associated With Resistance to Clarithromycin.},
journal = {Frontiers in cellular and infection microbiology},
volume = {12},
number = {},
pages = {868905},
pmid = {35402304},
issn = {2235-2988},
mesh = {Anti-Bacterial Agents/pharmacology/therapeutic use ; Biofilms ; Clarithromycin/pharmacology ; Drug Resistance, Bacterial ; *Helicobacter Infections/drug therapy ; *Helicobacter pylori/genetics ; Humans ; Levofloxacin/pharmacology ; Metronidazole/pharmacology ; Microbial Sensitivity Tests ; Microfluidics ; },
abstract = {It is widely accepted that production of biofilm is a protective mechanism against various type of stressors, including exposure to antibiotics. However, the impact of this structure on the spread of antibiotic resistance in Helicobacter pylori is still poorly understood. Therefore, the aim of the current research was to determine the relationship between biofilm formation and antibiotic resistance of H. pylori. The study was carried out on 24 clinical strains with different resistance profiles (antibiotic-sensitive, mono-resistant, double-resistant and multidrug-resistant) against clarithromycin (CLR), metronidazole (MTZ) and levofloxacin (LEV). Using static conditions and a crystal violet staining method, a strong correlation was observed between biofilm formation and resistance to CLR but not MTZ or LEV. Based on the obtained results, three the strongest and three the weakest biofilm producers were selected and directed for a set of microfluidic experiments performed in the Bioflux system combined with fluorescence microscopy. Under continuous flow conditions, it was observed that strong biofilm producers formed twice as much of biofilm and created significantly more eDNA and in particular proteins within the biofilm matrix when compared to weak biofilm producers. Additionally, it was noticed that strong biofilm producers had higher tendency for autoaggregation and presented morphostructural differences (a greater cellular packing, shorter cells and a higher amount of both OMVs and flagella) in relation to weak biofilm counterparts. In conclusion, resistance to CLR in clinical H. pylori strains was associated with a broad array of phenotypical features translating to the ability of strong biofilm formation.},
}
@article {pmid35400968,
year = {2022},
author = {Mitsuwan, W and Sornsenee, P and Romyasamit, C},
title = {Lacticaseibacillus spp.; Probiotic candidates from Palmyra palm sugar possesses antimicrobial and anti-biofilm activities against methicillin-resistant Staphylococcus aureus.},
journal = {Veterinary world},
volume = {15},
number = {2},
pages = {299-308},
pmid = {35400968},
issn = {0972-8988},
abstract = {Background and Aim: Probiotics are beneficial microorganisms that play important roles by adhering to the gut and producing antimicrobial substances to inhibit pathogens. The objective of this study was to isolate and characterize the probiotic lactic acid bacteria (LAB) from Palmyra palm sugar, which can produce antimicrobial compounds against methicillin-resistant Staphylococcus aureus (MRSA), a new zoonotic and food-borne pathogens.<br><br>Materials and Methods: Twenty-six LAB isolates were isolated from 30 Palmyra palm sugar samples. Three selected LAB were further characterized as probiotics. In addition, the antibacterial and anti-biofilm-forming activities of the probiotics' culture supernatants against MRSA and food-borne pathogens were investigated. Finally, the selected probiotics were identified by aligning 16S rRNA sequences.<br><br>Results: The three confirmed probiotics, WU 0904, WU 2302, and WU 2503, showed strong antibacterial activities against S. aureus, MRSA, Escherichia coli O157:H7, and Listeria monocytogenes, as measured by a broth microdilution assay. Among the LAB isolates, 82.22-86.58%, 91.83-96.06%, and 64.35-74.93% exhibited resistance to low pH, pancreatin treatment, and bile salts, respectively. It was found that 59.46% and 83.33% auto-aggregation was observed in 2 and 24 h, respectively. Moreover, 50.25-57.24% adhesion was detected after the incubation of the bacterial cells to Caco-2 cells.. Biofilm inhibition (82.81-87.24%) was detected after the treatment of MRSA with the culture supernatants, when compared with that to the control. By the alignment of 16S rRNA sequences, the isolate WU 2302 was identified as Lacticaseibacillus spp. with 98.82% homology when compared to the GenBank database.<br><br>Conclusion: This study indicates that isolated probiotics can produce antimicrobial compounds against MRSA and food-borne pathogens. The obtained results strongly suggest that these probiotics are promising candidates for pharmaceutical products.},
}
@article {pmid35400420,
year = {2022},
author = {Sun, J and Huang, L and Sun, Z and Wang, D and Liu, F and Du, L and Wang, D},
title = {Combination of ultrasound and chlorogenic acid for inactivation of planktonic and biofilm cells of Pseudomonas fluorescens.},
journal = {Food research international (Ottawa, Ont.)},
volume = {155},
number = {},
pages = {111009},
doi = {10.1016/j.foodres.2022.111009},
pmid = {35400420},
issn = {1873-7145},
mesh = {Biofilms ; Chlorogenic Acid/pharmacology ; Microscopy, Electron, Scanning ; Plankton ; *Pseudomonas fluorescens ; },
abstract = {This study investigated the synergistic efficacy of ultrasound (US, 50 kHz, 400 W) in combination with chlorogenic acid (CA; 0, 0.5, 1, and 2%) to inactivate Pseudomonas fluorescens planktonic and biofilm cells. The P. fluorescens planktonic and biofilm cells were treated with CA with and without US for 5, 10, 20, 30, or 60 min. Results showed that US enhanced the efficacy of CA for inactivation of both P. fluorescens planktonic and biofilm cells. Treatment with 2% CA and US could completely inactivate P. fluorescens planktonic cells within 10 min and the biofilm cells within 30 min. Confocal laser scanning microscopy (CLSM), scanning electron microscopy (SEM), ATP, and nucleic acid release assays indicated that the combination of US and CA could quickly damage the integrity of P. fluorescens planktonic and biofilm cell membranes. The combined treatment effectively inactivates P. fluorescens planktonic and biofilm cells via the synergetic destruction of the biofilm structure and bacterial cell integrity.},
}
@article {pmid35399651,
year = {2022},
author = {Prabu, R and Mohanty, A and Balakrishnan, SS and Jayalakshmi, G and Sundar, K},
title = {Molecular docking and simulation of IcaC protein as O-succinyltransferase function in staphylococcus epidermidis biofilm formation.},
journal = {Current research in structural biology},
volume = {4},
number = {},
pages = {78-86},
pmid = {35399651},
issn = {2665-928X},
abstract = {Intercellular adhesion (IcaADBC) operon is necessary for PNAG (Polyβ-1,6-N-acetyl-D-glucosamine) biosynthesis of biofilm formation in Staphylococcus epidermidis. IcaC protein has a wide range of functions in terms of growth phase variation, migration, transposon insertion, PNAG modification, biofilm formation. Unusual TTTA signature motifs were identified from nucleotide sequence. Asparagine-linked glycosylation consensus motifs were identified at position 169 and 240. S. epidermidis was a close evolutionary association with S. haemolyticus and other Staphylococcus spp. Due to the non-availability of crystal structure, protein threading procedure was selected for constructing a full length IcaC three-dimensional structure. QMEANBrane structure quality assessment with model scores -100000 range within predicted integral membrane structure. IcaC motif constitutes 18 transmembrane helix, 37 helix-helix interaction, 8 beta turn, 2 gamma turn. Binding free energy was calculated with their succinate ligand docking form hydrogen bond with critical amino acids showed ΔG score -2.574 ​kJ/mol using Schrödinger. Serine (Ser96), Glutamic acid (Glu99), Tryptophan (Trp191) were active site amino acids form the catalytic core required for O-succinyltransferase function. Molecular dynamics simulation (MDS) was performed to evaluate the stability of IcaC protein and IcaC-Succinate binding complexes with the active site amino acids throughout trajectories captured with time scale 100 ns simulation period using GROMACS 4.5.},
}
@article {pmid35398923,
year = {2022},
author = {Rodrigues, DS and Lannes-Costa, PS and Santos, GS and Ribeiro, RL and Langoni, H and Teixeira, LM and Nagao, PE},
title = {Antimicrobial resistance, biofilm production and invasion of mammary epithelial cells by Enterococcus faecalis and Enterococcus mundtii strains isolated from bovine subclinical mastitis in Brazil.},
journal = {Letters in applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/lam.13718},
pmid = {35398923},
issn = {1472-765X},
support = {//Sub-Reitoria de Pós-Graduação e Pesquisa da Universidade do Estado do Rio de Janeiro (SR-2/UERJ)/ ; 001//Coordenação de Aperfeiçoamento de Pessoal de Nível Superior/ ; //Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro/ ; //Conselho Nacional de Desenvolvimento Científico e Tecnológico/ ; },
abstract = {Members of the genus Enterococcus are among the most relevant etiologic agents of bovine clinical and subclinical mastitis, a major problem for the dairy industry. In Brazil, clonal diversity, and multidrug resistance profiles related to bovine infections need further investigation. In this study, 11 bacterial strains recovered from mastitis subclinical cases detected in different farms of São Paulo, Brazil, were identified as Enterococcus faecalis (n = 8) and Enterococcus mundtii (n = 3) by biochemical testing and MALDI-TOF mass spectrometry. Pulsed-field gel electrophoresis categorized the enterococcal isolates into two main clusters (A and B) with similarity ranging from 85 to 100%. The isolates were shown to be resistant tetracycline (73%), erythromycin (73%), quinupristin-dalphopristin (64%), norfloxacin (9%), fosfomycin (9%) and linezolid (9%). Moreover, seven strains (64%) were considered multidrug-resistant. All the isolates were able to produce biofilms when grown in milk for 24 h: 54·54% were classified as moderate producers and 45·45% were weak producers. Interestingly, only two strains (Ef17 and Em42) remained as moderate biofilm producers after 48 h incubation. Moreover, all isolates showed no ability to form biofilm in tryptic soy broth (TSB) after 24 and 48 h incubation. In addition, cytoskeleton components were partially involved in E. faecalis and E. mundtii entry to epithelial cells as demonstrated by induction of actin stress fibre. In conclusion, enterococci isolates recovered from bovine subclinical mastitis were resistant to several classes of antibiotics, showing the ability to form biofilms in milk and invade mammary epithelial cells, suggesting an advantageous feature in mammary gland colonization during mastitis development. In addition, they can spread along the food chain by different routes and eventually constitute a possible threat for public health, including E. mundtii specie.},
}
@article {pmid35398730,
year = {2022},
author = {Huan, X and Wang, Y and Peng, X and Xie, S and He, Q and Zhang, X and Lan, L and Yang, C},
title = {Design, synthesis, and biological evaluations of substituted pyrazoles as pyrrolomycin analogues against staphylococcal biofilm.},
journal = {European journal of medicinal chemistry},
volume = {236},
number = {},
pages = {114309},
doi = {10.1016/j.ejmech.2022.114309},
pmid = {35398730},
issn = {1768-3254},
mesh = {Anti-Bacterial Agents/pharmacology ; Biofilms ; Humans ; *Methicillin-Resistant Staphylococcus aureus ; Microbial Sensitivity Tests ; Pyrazoles/pharmacology ; *Staphylococcal Infections ; Staphylococcus ; Staphylococcus aureus ; },
abstract = {The formation of biofilm enables Staphylococcus aureus to resist antibiotics and causes chronic infections. Several compounds of pyrrolomycins are potent antibacterial agents which display inhibition upon staphylococcal biofilms. We designed and synthesized two series of substituted pyrazoles as pyrrolomycin analogues. Compounds 17a, 17d and 17h displayed potent antibacterial activity against various vancomycin-resistant Enterococcus faecalis (VRE) and methicillin-resistant Staphylococcus aureus (MRSA), and 17d showed the most potent activity against MRSA (MIC = 0.0625 μg/mL), vancomycin-intermediate Staphylococcus aureus (VISA) (MIC = 0.0313 μg/mL). Further study indicated that compound 17h could significantly reduce the biofilm formation of MRSA and exhibited promising selectivity. In vitro liver microsomal stability was also evaluated and the results manifested that 17h was metabolically stable in human liver microsomes.},
}
@article {pmid35398435,
year = {2022},
author = {Hou, J and Shao, G and Adyel, TM and Li, C and Liu, Z and Liu, S and Miao, L},
title = {Can the carbon metabolic activity of biofilm be regulated by the hydrodynamic conditions in urban rivers?.},
journal = {The Science of the total environment},
volume = {832},
number = {},
pages = {155082},
doi = {10.1016/j.scitotenv.2022.155082},
pmid = {35398435},
issn = {1879-1026},
abstract = {Hydrodynamic regulation is widely used to improve the water quality of urban rivers. However, it is yet to explore substantially whether hydrodynamics could regulate the metabolic activity of biofilm in such aquatic systems. Herein, the pilot experiment of hydrodynamics in the rotation tanks was designed, including two experiment phases, namely constant flow and adjusting flow for 21 days and 14 days, respectively. In constant flow phase, biofilms grew in five shear stress gradients (R1-R5, 0.0044- 0.12 Pa). The carbon metabolic rate (k) of mature biofilms evaluated by BIOLOG ECO microplates showed a hump-shaped relationship with increasing shear stress, with R3 (0.049 Pa) the highest, while R5 (0.12 Pa) the lowest. To verify whether the metabolic activity of biofilm cultured at constant flow phase can be regulated by shear stress, we initiated the adjusting flow phase, and shear stress in reactors was reset uniformly at 0.049 Pa (with the highest k). Results showed the carbon metabolic activity of biofilm in reactor R4 and R5 increased rapidly by day 3, and there was no significant difference between the carbon metabolic rates among the five treatments by day 14. Meanwhile, the utilization levels of polymers and carbohydrates by biofilms were significantly different among the five treatments after hydrodynamic regulations. These results suggested that the total carbon metabolic activity of biofilm can be regulated by hydrodynamics, while the divergent changes of the specific carbon source category might affect the biofilm-mediated carbon biogeochemical processes, which should be considered for the application of hydrodynamic regulation in river ecological restoration projects.},
}
@article {pmid35398128,
year = {2022},
author = {Lu, B and Jiang, C and Chen, Z and Li, A and Wang, W and Zhang, S and Luo, G},
title = {Fate of polylactic acid microplastics during anaerobic digestion of kitchen waste: Insights on property changes, released dissolved organic matters, and biofilm formation.},
journal = {The Science of the total environment},
volume = {834},
number = {},
pages = {155108},
doi = {10.1016/j.scitotenv.2022.155108},
pmid = {35398128},
issn = {1879-1026},
abstract = {Polylactic acid (PLA), an alternative to petroleum-based plastics, has been widely used in food packaging and disposable tableware for biodegradable properties. As a result, PLA fragments were often mixed with kitchen waste (KW) and disposed of together. This study aimed to assess the fate of polylactic acid microplastics (PMP) when co-digested with KW. The spiked PMP did not increase the methane yield of KW but had deformation and fragmentation at mesophilic and thermophilic conditions, respectively. Identification of physicochemical properties and leachates showed that the anaerobic digestion of the KW process caused the aging and fragmentation of PMP, including the generation of irregular cracking and tiny daughter particles, the increase of oxygen-containing functional groups, and the releasing of dissolved organic matters (DOM). The thermophilic anaerobic digestion with KW enhanced the aging and fragmentation of PMP to the highest degree, which was attributed to the high temperature and enriched microorganisms (Peptococcaceae, Tepidimicrobium, and Clostridium_sensu_stricto_7) in the biofilm. Clostridium_sensu_stricto_7 was only found in the anaerobic digestion with KW, which meant the KW anaerobic digestion could contribute to the enrichment of microorganisms that promoted the PMP degradation.},
}
@article {pmid35397438,
year = {2022},
author = {Li, Z and Huang, L and Hao, W and Yang, J and Qian, H and Zhang, D},
title = {Accelerating effect of pyocyanin on microbiologically influenced corrosion of 304 stainless steel by the Pseudomonas aeruginosa biofilm.},
journal = {Bioelectrochemistry (Amsterdam, Netherlands)},
volume = {146},
number = {},
pages = {108130},
doi = {10.1016/j.bioelechem.2022.108130},
pmid = {35397438},
issn = {1878-562X},
abstract = {In this study, the influence of exogenous pyocyanin (PYO) on the microbiologically influenced corrosion (MIC) of 304 stainless steel by Pseudomonas aeruginosa was investigated. Under sterile condition, the additional PYO in the culture medium had no effect on the corrosion of 304 stainless steel. In contrast, P. aeruginosa biofilm inoculated in the media with additional PYO resulted in more severe pitting corrosion. EIS and cyclic potentiodynamic polarization results indicated that exogenous PYO promoted the electron transfer efficiency between the P. aeruginosa biofilm and the stainless steel surface. X-ray photoelectron spectroscopy (XPS) and transmission electron microscope (TEM) results further demonstrated that the P. aeruginosa led the breakdown of passive film predominantly by accelerating the bioreductive dissolution of iron oxides.},
}
@article {pmid35396841,
year = {2022},
author = {Zaidi, A},
title = {Correction to: Biofilm development in L. fermentum under shear flow &amp; sequential GIT digestion.},
journal = {FEMS microbiology letters},
volume = {369},
number = {1},
pages = {},
doi = {10.1093/femsle/fnac027},
pmid = {35396841},
issn = {1574-6968},
}
@article {pmid35396139,
year = {2022},
author = {Barnier, C and Clerissi, C and Lami, R and Intertaglia, L and Lebaron, P and Grimaud, R and Urios, L},
title = {Corrigendum to "Description of Palleronia rufa sp. nov., a biofilm-forming and AHL-producing Rhodobacteraceae, reclassification of Hwanghaeicola aestuarii as Palleronia aestuarii comb. nov., Maribius pontilimi as Palleronia pontilimi comb. nov., Maribius salinus as Palleronia salina comb. nov., Maribius pelagius as Palleronia pelagia comb. nov. and emended description of the genus Palleronia" [Syst. Appl. Microbiol. 43 (1) (2020) 126018].},
journal = {Systematic and applied microbiology},
volume = {},
number = {},
pages = {126321},
doi = {10.1016/j.syapm.2022.126321},
pmid = {35396139},
issn = {1618-0984},
}
@article {pmid35395437,
year = {2022},
author = {Karbysheva, S and Cabric, S and Koliszak, A and Bervar, M and Kirschbaum, S and Hardt, S and Perka, C and Trampuz, A},
title = {Clinical evaluation of dithiothreitol in comparison with sonication for biofilm dislodgement in the microbiological diagnosis of periprosthetic joint infection.},
journal = {Diagnostic microbiology and infectious disease},
volume = {103},
number = {2},
pages = {115679},
doi = {10.1016/j.diagmicrobio.2022.115679},
pmid = {35395437},
issn = {1879-0070},
mesh = {*Arthritis, Infectious/diagnosis ; Biofilms ; Dithiothreitol ; Humans ; Prospective Studies ; *Prosthesis-Related Infections/diagnosis/microbiology ; Sensitivity and Specificity ; Sonication ; },
abstract = {Sonication of explanted devices is well investigated method and was shown to improve the microbiological diagnosis of impant-associated infections by physical removal of bacterial biofilms. Recently, novel approach with chemical agents have been investigated for biofilm dislodgement such as dithiothreitol (DTT). We compared the biofilm dislodgement efficacy of chemical method (dithiothreitol, DTT) compared to the sonication procedure in the diagnosis of prosthetic joint infections (PJI). In a prospective cohort, 187 patients undergoing hip and knee prostheses explantation were included, of whom 94 were assigned for sonication and 93 for DTT group. Sonication showed better sensitivity (73.8%) than DTT (43.2%) for the diagnosis of PJI and comparable specificity (98% and 94.6%, respectively). We concluded that sonication provides a more reliable diagnosis of PJI and detects about 30% more pathogens compared to DTT system. The study was registered at ClinicalTrials.gov (NCT02530229).},
}
@article {pmid35395366,
year = {2022},
author = {Gao, D and Li, Y and Liang, H},
title = {Biofilm carriers for anaerobic ammonium oxidation: Mechanisms, applications, and roles in mainstream systems.},
journal = {Bioresource technology},
volume = {353},
number = {},
pages = {127115},
doi = {10.1016/j.biortech.2022.127115},
pmid = {35395366},
issn = {1873-2976},
mesh = {*Ammonium Compounds ; Anaerobiosis ; Biofilms ; Bioreactors/microbiology ; *Denitrification ; Nitrogen ; Oxidation-Reduction ; Sewage/microbiology ; },
abstract = {The anaerobic ammonium oxidation (ANAMMOX) process was proposed as the most promising nitrogen removal process. Biofilm carriers were demonstrated to effectively enhance the anaerobic ammonium oxidating bacteria (AnAOB) retention. This paper reviews the effect of carrier properties on the AnAOB biofilm development according to the biofilm development process and the application state-of-art of three major kinds of conventional carriers, organic-based, inorganic-based carriers, and gel carriers, from the view of system performance and functional microorganisms. The carrier modification methods and purpose are thoroughly summarized and classified into three categories corresponding to various carrier defects. Four important aspects of the desirable carrier for the mainstream ANAMMOX process were proposed, including providing spatial configuration, enhancing the biomass retention, reinforcing the activity, and improving the growth environment, which needs to combine the advantages of organic and inorganic materials. Eventually, the future application directions of novel carriers for the ANAMMOX-based process were also highlighted.},
}
@article {pmid35395308,
year = {2022},
author = {Zhou, Y and Anwar, MN and Guo, B and Huang, W and Liu, Y},
title = {Response of antibiotic resistance genes and microbial niches to dissolved oxygen in an oxygen-based membrane biofilm reactor during greywater treatment.},
journal = {The Science of the total environment},
volume = {833},
number = {},
pages = {155062},
doi = {10.1016/j.scitotenv.2022.155062},
pmid = {35395308},
issn = {1879-1026},
abstract = {Linear alkylbenzene sulfonates (LAS) in greywater (GW) will simulate antibiotic resistance genes (ARGs) production in the biofilm-based system. Our study emphasizes the dissolved oxygen (DO)-dependent ARGs accumulation and microbial niches succession in an oxygen-based membrane biofilm reactor (O2-MBfR) treating GW, as well as revealing the key roles of EPS. Changing DO concentrations led to significant differences in ARGs production, EPS secretion and microbial communities, as well as the organics and nitrogen removal efficiency. Increasing DO concentration from 0.2 to 0.4 mg/L led to improved organics (> 90%) and nitrogen removal, as well as less EPS (especially for proteins and carbohydrates) and ARGs accumulation (e.g., intI-1, korB and sul-2) in the biofilm; the high-DO-concentration accumulated microbial niches, including Flavobacteriaceae and Cyanobacteria that revealed by LEfSe analysis, contributed to both nitrogen reduction and organics biodegradation. While, the inefficient electron acceptor at low DO conditions (0.2 mg/L) reduced the organics and nitrogen removal efficiency, as well as the improved accumulation of EPS in biofilm; high EPS enabled the capture of residual LAS from the liquid phase, which stimulated the production of ARGs by the distinct microbial community compositions. These findings suggested the DO-based ARGs reduction regulation strategy in the O2-MBfR treating GW.},
}
@article {pmid35394280,
year = {2022},
author = {Chen, H and Cheng, J and Cai, X and Han, J and Chen, X and You, L and Xiong, C and Wang, S},
title = {pH-Switchable Antimicrobial Supramolecular Hydrogels for Synergistically Eliminating Biofilm and Promoting Wound Healing.},
journal = {ACS applied materials &amp; interfaces},
volume = {14},
number = {16},
pages = {18120-18132},
doi = {10.1021/acsami.2c00580},
pmid = {35394280},
issn = {1944-8252},
mesh = {Anti-Bacterial Agents/chemistry/pharmacology ; *Anti-Infective Agents/pharmacology ; Biofilms ; Humans ; Hydrogels/chemistry/pharmacology ; Hydrogen-Ion Concentration ; Wound Healing ; *Wound Infection/drug therapy ; },
abstract = {Biofilm infection will cause chronic inflammation and hinder the normal healing process of wound. Here, based on the self-assembly of three designed amphiphilic pentapeptides named EK, GG, and DR, pH-switchable antibacterial hydrogels with amphiphilic fiber network are used for the eradication of biofilms and the rescue of delayed healing in infected wounds. These pentapeptides-based hydrogels exhibit an acidic pH-switchable antimicrobial effect and are biocompatible at neutral pH. Additionally, supramolecular nanofiber networks with physical cross-linking with thermosensitive polymers (PNIPAm) and loaded antibacterial oregano oil are further developed. In vitro experiments indicate that the antimicrobial activity of hydrogels comes from the disassembly of acidic pH-dependent nanofiber network and activated release of pentapeptides and oregano oil, which achieves synergistic biofilm eradication. Remarkably, DR-based supramolecular hydrogel improves the healing efficiency of the full-thickness wound of skin in vivo, which is manifested by increased wound closure rate, reduced inflammatory response, faster angiogenesis, and collagen deposition in the wound, exhibiting great potential as wound dressing. The proposed synergistic strategy of inhibiting biofilm formation and activating healing may provide an efficient method for the treatment of clinically infected wounds.},
}
@article {pmid35393828,
year = {2022},
author = {Zheng, XW and Qin, JF and Wang, XJ and Chen, HC and Zhu, ZJ and Chen, ZG},
title = {[Promoting Nitrogen Removal in ANAMMOX Biofilm Reactor by Fe2+ Under Low Nitrogen Concentration].},
journal = {Huan jing ke xue= Huanjing kexue},
volume = {43},
number = {4},
pages = {2047-2054},
doi = {10.13227/j.hjkx.202107071},
pmid = {35393828},
issn = {0250-3301},
mesh = {*Ammonium Compounds ; Anaerobic Ammonia Oxidation ; Anaerobiosis ; Biofilms ; Bioreactors/microbiology ; Denitrification ; Extracellular Polymeric Substance Matrix/chemistry ; *Nitrogen/analysis ; Oxidation-Reduction ; Sewage ; Waste Water ; },
abstract = {The feasibility for nitrogen removal in a two-stage ANAMMOX biofilm reactor promoted by Fe2+ under low nitrogen concentration was investigated. The results showed that the ANAMMOX reaction could be effectively promoted by a ρ(Fe2+) of 5, 10, and 15 mg·L-1. A ρ(Fe2+) of 10 mg·L-1 presented the highest promotion for the ANAMMOX reaction, with the highest nitrogen removal efficiency (NRE) of 81.71% under a ρ(TN) of 150 mg·L-1and a nitrogen loading rate (NLR) of 0.62 kg·(m3·d)-1. Fe2+ promoted the secretion of extracellular polymeric substance (EPS) and the synthesis of heme c in the ANAMMOX system. Batch test results further verified the positive effects by Fe2+on the activity of anaerobic ammonium oxidizing bacteria (AnAOB). The specific ANAMMOX activity (SAA) of 10 mg·L-1 ρ(Fe2+) was 3.6 times as high as that of the control group[ρ(Fe2+)=0 mg·L-1], whereas the activity of AnAOB was significantly inhibited with ρ(Fe2+) increased to 20 mg·L-1. High-throughput sequencing results showed that the addition of Fe2+ increased the abundance of Candidatus_Kuenenia. When ρ(Fe2+) was 10 mg·L-1, the relative abundance of Candidatus_Kuenenia in reactor 1 and reactor 2 increased to 16.18% and 4.22%, respectively. The stable operation of the two-stage ANAMMOX biofilm process promoted by Fe2+provides an alternative technology for low-strength nitrogen wastewater.},
}
@article {pmid35393459,
year = {2022},
author = {Belleville, P and Merlin, G and Ramousse, J and Deseure, J},
title = {Characterization of spatiotemporal electroactive anodic biofilm activity distribution using 1D simulations.},
journal = {Scientific reports},
volume = {12},
number = {1},
pages = {5849},
pmid = {35393459},
issn = {2045-2322},
mesh = {Acetates ; *Biofilms ; Biomass ; Electrodes ; *Extracellular Polymeric Substance Matrix ; },
abstract = {Activity distribution limitation in electroactive biofilm remains an unclear phenomenon. Some observations using confocal microscopy have shown notable difference between activity close to the anode and activity at the liquid interface. A numerical model is developed in this work to describe biofilm growth and local biomass segregation in electroactive biofilm. Under our model hypothesis, metabolic activity distribution in the biofilm results from the competition between two limiting factors: acetate diffusion and electronic conduction in the biofilm. Influence of inactive biomass fraction (i.e. non-growing biomass fraction) properties (such as conductivity and density) is simulated to show variation in local biomass distribution. Introducing a dependence of effective diffusion to local density leads to a drastic biomass fraction segregation. Increasing density of inactive fraction reduces significantly acetate diffusion in biofilm, enhances biomass activity on the outer layer (liquid/biofilm interface) and maintains inner core largely inactive. High inactive fraction conductivity enhances biomass activity in the outer layer and enhances current production. Hence, investment in extracellular polymer substance (EPS), anchoring redox components, is benefit for biofilm electroactivity. However, under our model hypothesis it means that conductivity should be two order lower than biofilm conductivity reported in order to observe inner core active biomass segregation.},
}
@article {pmid35390615,
year = {2022},
author = {Luo, X and Yang, Y and Xie, S and Wang, W and Li, N and Wen, C and Zhu, S and Chen, L},
title = {Drying and rewetting induce changes in biofilm characteristics and the subsequent release of metal ions.},
journal = {Journal of hazardous materials},
volume = {433},
number = {},
pages = {128832},
doi = {10.1016/j.jhazmat.2022.128832},
pmid = {35390615},
issn = {1873-3336},
mesh = {Bacteria/genetics ; Biofilms ; *Cadmium ; Desiccation ; Ions ; *Metals, Heavy ; },
abstract = {Drying and rewetting can markedly influence the microbial structure and function of river biofilm communities and potentially result in the release of metal ions from biofilms containing metals. However, little information is available on the response of metal-enriched biofilms to drying and rewetting over time. In this study, natural biofilms were allowed to develop in four rotating annular bioreactors for 2-11 weeks, followed by drying for 5 days and rewetting for another 5 days. Subsequently, we assessed Zn, Cd, and As desorption from the biofilms and other related parameters (microbial community structure, biofilm morphology, enzyme activity, and surface components as well as characteristics). High-throughput sequencing of the 16 S rRNA gene and confocal laser scanning microscopy revealed that the biofilm architecture and bacterial communities were distinct in different growth phases and under drying and rewetting conditions (permutational multivariate analysis of variance; p = 0.001). Proteobacteria was the dominant bacterial phylum, accounting for 69.7-90.1% of the total content. Kinetic experiments revealed that the drying and rewetting process increased metal desorption from the biofilm matrix. The desorption of heavy metals was affected by the age of the biofilm, with the maximum amount of metal ions released from 2-week-old biofilms (one-way ANOVA, Zn: p < 0.001; Cd: p = 0.008; As: p < 0.001). The modifications in biofilm properties and decreased diversity of the bacterial community (paired t-test, p < 0.05) after drying and rewetting decreased the number of specific binding sites for metal ions. In addition, negatively charged arsenate and other anions in the liquid phase could compete with As ions for adsorption sites to promote the release of As(V) and/or reductive desorption of As(III). The results of this study and their interpretation are expected to help refine the behaviors of heavy metals in the aquatic environment.},
}
@article {pmid35390370,
year = {2022},
author = {Li, J and Ma, J and Liao, H and Li, X and Shen, L and Lin, H and Sun, L and Ou, R and He, D},
title = {Hot-pressed membrane assemblies enhancing the biofilm formation and nitrogen removal in a membrane-aerated biofilm reactor.},
journal = {The Science of the total environment},
volume = {833},
number = {},
pages = {155003},
doi = {10.1016/j.scitotenv.2022.155003},
pmid = {35390370},
issn = {1879-1026},
abstract = {Membrane-aerated biofilm reactor (MABR) is gaining popularity in wastewater treatment as a result of the low-energy delivery of oxygen from the carrier side and reduced sludge waste production, although its wider application suffers from the difficulty in microbial colonization on the smooth, hydrophobic membrane surface. In this study, a newly designed membrane/non-woven fabric assembly, prepared via a facile hot-pressing method, is demonstrated to be efficient in promoting the biofilm formation and nitrogen removal in MABR. The assembly achieved rough surface structure to retain biomass whilst sustained the surface hydrophobicity for a high oxygen transfer ability, which is crucial to support a resilient biofilm. Compared with the slower biomass growth and severe detachment of biofilm in the control, a thicker biofilm was quickly developed on the hot-pressed membrane assembly. High loading rates of organic matter, ammonia nitrogen and total nitrogen (TN) in the MABR using the hot-pressed membrane were 154.9 ± 5.4 g COD/(m2·d), 25.5 ± 0.6 g N/(m2·d) and 22.6 ± 0.7 g N/(m2·d), respectively. Particularly, the removal efficiency of TN was up to 82.8%, which was 2.5 times higher than the control. Furthermore, the biofilm grown on the hot-pressed membrane assembly organized a stable microbial community structure with a steady evolution to achieve a synergistic denitrifying function. Among the bacterial phylotypes, OLB8 might be crucial in denitrification. This study highlighted the significance of this facile membrane modification method to improve the process performance of MABR in wastewater treatment.},
}
@article {pmid35390153,
year = {2022},
author = {Hayer, JJ and Heinemann, C and Schulze-Dieckhoff, BG and Steinhoff-Wagner, J},
title = {A risk-oriented evaluation of biofilm and other influencing factors on biological quality of drinking water for dairy cows.},
journal = {Journal of animal science},
volume = {100},
number = {5},
pages = {},
doi = {10.1093/jas/skac112},
pmid = {35390153},
issn = {1525-3163},
abstract = {Despite the importance of livestock drinking water quality on animal physiology, welfare, and performance, influences such as biofilm formation on trough surfaces on microbial water quality are rarely researched. The objective of this study was to assess the microbial quality of water offered to lactating dairy cows and identify risk factors for poor water quality. We further aimed to determine the impact of biofilm formation on water quality and evaluate rapid test systems to score the hygiene status of dairy troughs on the farm. A total of 105 troughs located on 24 typical Western German dairy farms were sampled. Samples of livestock drinking water and biofilm were analyzed for aerobic total viable count (TVC), coliform count (CC), Escherichia coli, methicillin-resistant Staphylococcus aureus (MRSA), and other bacteria resistant to 3rd generation cephalosporins (CRB). Surface protein- and adenosine triphosphate (ATP)-rapid tests were evaluated to detect biofilm formation. The influence of 22 selected fixed and variable trough characteristics on impaired livestock drinking water quality was evaluated by calculating odds ratios. The average TVC, CC, and E. coli counts were 4.4 ± 0.06 (mean ± SD), 1.7 ± 0.1, and 0.6 ± 0.1 log10 cfu per mL, respectively. CC was detectable in 94.3% of all water samples and E. coli in 48.6%. MRSA was found in pooled livestock drinking water samples of a single farm and CRB on three farms, suggesting that troughs might function as a reservoir of antibiotic-resistant bacteria, thereby contributing to an exchange of antibiotic-resistant bacteria between animals. Risk factors for the impairment of at least one microbial quality criteria (TVC, CC, or E. coli) increased significantly (P < 0.05) when using high-volume troughs, other trough materials than stainless steel, a lower distance to the milking parlor, heavy visible soiling, biofilm formation, and high ambient and high water temperatures. CC (r = 0.46; P < 0.001) and E. coli (r = 0.31; P < 0.01) of water samples correlated with their equivalent in biofilm and with the results of rapid tests on trough surfaces (0.31 > r > 0.19; P < 0.05). Addressing the identified risk factors could be an approach to ensure sufficient biological quality of livestock drinking water.},
}
@article {pmid35387914,
year = {2022},
author = {Kaga, H and Nakamura, A and Orita, M and Endo, K and Akamatsu, M and Sakai, K and Sakai, H},
title = {Removal of a Model Biofilm by Sophorolipid Solutions: A QCM-D Study.},
journal = {Journal of oleo science},
volume = {71},
number = {5},
pages = {663-670},
doi = {10.5650/jos.ess21360},
pmid = {35387914},
issn = {1347-3352},
mesh = {Biofilms ; Oleic Acids ; *Quartz Crystal Microbalance Techniques ; Viscosity ; *beta-Glucans ; },
abstract = {Biofilms are communities of microorganisms that have been widely studied because they can cause hospital-acquired infections and skin disorders. Polysaccharides secreted by microorganisms are constituents of biofilms, contributing to their adhesion and mechanical stability. Sophorolipids are biosurfactants with the ability to disrupt and remove biofilms. Biosurfactants have been targeted as potential substitutes for classical petrochemical-based surfactants in cosmetics. In this study, we fabricate a β-glucan film as a model biofilm, and quartz crystal microbalance with dissipation monitoring (QCM-D) measurements are used to assess the biofilm removal. The viscoelasticity of the β-glucan films is monitored while sophorolipid solutions are introduced into the system, and we found that the film removal performance increases with the sophorolipid concentration. In addition, Δf (change in frequency)-ΔD (change in energy dissipation) plot analyses reveal that two processes are involved in the removal mechanism. The first process involves the adsorption of water (hydration) on the β-glucan film. The second process involves the removal of the β-glucan film from the sensor surface. Furthermore, it is suggested that sophorolipids interfere with the hydration of the β-glucan film and suppress increases in its viscosity. This is expected to be an essential factor for the removal of the β-glucan film. Sophorolipids, therefore, show potential for use in cosmetics as an eco-friendly agent for biofilm removal.},
}
@article {pmid35387171,
year = {2022},
author = {Hu, J and Ding, Y and Tao, B and Yuan, Z and Yang, Y and Xu, K and Li, X and Liu, P and Cai, K},
title = {Surface modification of titanium substrate via combining photothermal therapy and quorum-sensing-inhibition strategy for improving osseointegration and treating biofilm-associated bacterial infection.},
journal = {Bioactive materials},
volume = {18},
number = {},
pages = {228-241},
pmid = {35387171},
issn = {2452-199X},
abstract = {Insufficient osseointegration and biofilm-associated bacterial infection are important challenges for clinical application of titanium (Ti)-based implants. Here, we constructed mesoporous polydopamine (MPDA) nanoparticles (NPs) loaded with luteolin (LUT, a quorum sensing inhibitor), which were further coated with the shell of calcium phosphate (CaP) to construct MPDA-LUT@CaP nanosystem. Then, MPDA-LUT@CaP NPs were immobilized on the surface of Ti implants. Under acidic environment of bacterial biofilm-infection, the CaP shell of MPDA-LUT@CaP NPs was rapidly degraded and released LUT, Ca2+ and PO4 3- from the surface of Ti implant. LUT could effectively inhibit and disperse biofilm. Furthermore, under near-infrared irradiation (NIR), the thermotherapy induced by the photothermal conversion effect of MPDA destroyed the integrity of the bacterial membrane, and synergistically led to protein leakage and a decrease in ATP levels. Combined with photothermal therapy (PTT) and quorum-sensing-inhibition strategy, the surface-functionalized Ti substrate had an antibacterial rate of over 95.59% against Staphylococcus aureus and the elimination rate of the formed biofilm was as high as 90.3%, so as to achieve low temperature and efficient treatment of bacterial biofilm infection. More importantly, the modified Ti implant accelerated the growth of cell and the healing process of bone tissue due to the released Ca2+ and PO4 3-. In summary, this work combined PTT with quorum-sensing-inhibition strategy provides a new idea for surface functionalization of implant for achieving effective antibacterial and osseointegration capabilities.},
}
@article {pmid35386819,
year = {2022},
author = {Yang, G and Wang, DY and Liu, Y and Huang, F and Tian, S and Ren, Y and Liu, J and An, Y and van der Mei, HC and Busscher, HJ and Shi, L},
title = {In-biofilm generation of nitric oxide using a magnetically-targetable cascade-reaction container for eradication of infectious biofilms.},
journal = {Bioactive materials},
volume = {14},
number = {},
pages = {321-334},
pmid = {35386819},
issn = {2452-199X},
abstract = {Cascade-reaction chemistry can generate reactive-oxygen-species that can be used for the eradication of infectious biofilms. However, suitable and sufficient oxygen sources are not always available near an infection site, while the reactive-oxygen-species generated are short-lived. Therefore, we developed a magnetic cascade-reaction container composed of mesoporous Fe3O4@SiO2 nanoparticles containing glucose-oxidase and l-arginine for generation of reactive-oxygen-species. Glucose-oxidase was conjugated with APTES facilitating coupling to Fe3O4@SiO2 nanoparticles and generation of H2O2 from glucose. l-arginine was loaded into the nanoparticles to generate NO from the H2O2 generated. Using an externally-applied magnetic field, cascade-reaction containers could be homogeneously distributed across the depth of an infectious biofilm. Cascade-reaction containers with coupled glucose-oxidase were effective in killing planktonic, Gram-positive and Gram-negative bacteria. Additional efficacy of the l-arginine based second cascade-reaction was only observed when H2O2 as well as NO were generated in-biofilm. In vivo accumulation of cascade-reaction containers inside abdominal Staphylococcus aureus biofilms upon magnetic targeting was observed real-time in living mice through an implanted, intra-vital window. Moreover, vancomycin-resistant, abdominal S. aureus biofilms could be eradicated consuming solely endogenous glucose, without any glucose addition. Herewith, a new, non-antibiotic-based infection-control strategy has been provided, constituting a welcome addendum to the shrinking clinical armamentarium to control antibiotic-resistant bacterial infections.},
}
@article {pmid35384988,
year = {2022},
author = {Levy, FM and Braga, AS and Pelá, VT and Lavender, S and Zhang, D and Pilch, S and Malheiros, Z and Stewart, B and Magalhães, AC and Buzalaf, MAR},
title = {Characterization of white spot lesions formed on human enamel under microcosm biofilm for different experimental periods.},
journal = {Journal of applied oral science : revista FOB},
volume = {30},
number = {},
pages = {e20210560},
pmid = {35384988},
issn = {1678-7765},
mesh = {Biofilms ; *Dental Caries ; Dental Enamel ; Humans ; Microradiography ; Saliva ; *Tooth Demineralization ; Tooth Remineralization ; },
abstract = {The initial characteristics of white spot lesion (WSLs), such as the degree of integrated mineral loss (ΔZ), depth and pattern of mineral distribution, have an impact on further demineralization and remineralization. However, these lesion parameters have not been evaluated in WSLs produced from microcosm biofilms.<br><br>OBJECTIVE: This study characterized artificial white spot lesions produced on human enamel under microcosm biofilm for different experimental periods.<br><br>METHODOLOGY: In total, 100 human enamel specimens (4x4mm) were assigned to 5 distinct groups (n=20/group) differing according to the period of biofilm formation (2, 4, 6, 8 or 10 days). Microcosm biofilm was produced on the specimens from a mixture of human and McBain saliva at the first 8h. Enamel samples were then exposed to McBain saliva containing 0.2% sucrose. WSLs formed were characterized by quantitative light-induced fluorescence (QLF) and transverse microradiography (TMR). Data were analyzed by ANOVA/Tukey or Kruskal-Wallis/Dunn tests (p<0.05).<br><br>RESULTS: A clear time-response pattern was observed for both analyses, but TMR was able to better discriminate among the lesions. Regarding QLF analysis, median (95%CI; %) changes in fluorescence ∆Z were -7.74(-7.74:-6.45)a, -8.52(-8.75:-8.00)ab, -9.17(-10.00:-8.71)bc, -9.58(-10.53:-8.99)bc and -10.01(-11.44:-9.72)c for 2, 4, 6, 8, and 10 days, respectively. For TMR, median (95%CI; vol%.µm) ∆Z were 1410(1299-1479)a, 2420(2327-2604)ab, 2775(2573-2899)bc, 3305(3192-3406)cd and 4330(3972-4465)d, whereas mean (SD; µm) lesion depth were 53.7(12.3)a, 71.4(12.0)a, 103.8(24.8)b, 130.5(27.2)bc, 167.2(39.3)c for 2, 4, 6, 8 and 10 days, respectively.<br><br>CONCLUSION: The progression of WSLs formed on human enamel under microcosm biofilm can be characterized over 2-10 days, both by QLF and TMR analyses, although the latter provides better discrimination among the lesions.},
}
@article {pmid35384183,
year = {2022},
author = {Benny, AT and Rathinam, P and Dev, S and Mathew, B and Radhakrishnan, EK},
title = {Perillaldehyde mitigates virulence factors and biofilm formation of Pseudomonas aeruginosa clinical isolates, by acting on the quorum sensing mechanism in vitro.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1111/jam.15565},
pmid = {35384183},
issn = {1365-2672},
abstract = {AIM: The incidence of biofilm linked catheter-associated urinary tract infections is increasing worldwide and Pseudomonas aeruginosa is one of the major causes. Perillaldehyde (PLD): as a natural, widely used flavouring agent, has been reported to possess various pharmacological properties. We hypothesized that PLD can inhibit biofilm formation and virulence factor (VF) production by P. aeruginosa by hampering the quorum sensing (QS) system(s).<br><br>METHODS AND RESULTS: Minimum inhibitory concentration (MIC) of PLD was assessed for standard strain and two multi-drug resistant catheter isolates of P. aeruginosa utilizing the microdilution method. Microtiter plate assay, crystal violet staining and scanning electron microscopy were used to evaluate the biofilm inhibition property. CFU was utilized to assess the antifouling property of PLD. Detection of VFs and expression analysis of virulence determinants were applied to investigate the anti-virulence activity. Gene expression and molecular docking studies were also executed to explore the QS inhibition and binding of PLD with QS receptors. In the present study, PLD has significantly inhibited biofilm formation and antivirulence activity at sub-MIC levels (2.5 and 3.5 mM) in all the tested strains. In addition, molecular docking studies revealed a significant affinity towards QS receptors.<br><br>DISCUSSIONS: Perillaldehyde, being a non-toxic food flavouring agent, significantly inhibited biofilm formation and exhibited antifouling property. PLD exhibited significantly reduced levels of VFs (p < 0.001) and their respective genetic determinants (p < 0.001). Gene expression analysis and molecular docking studies confirmed the interactions of PLD to the QS receptors, indicating the plausible mechanism for the anti-virulence property.<br><br>This study identified the anti-virulence potential of PLD and provided mechanistic insights. PLD can be a suitable, non-toxic candidate for countering biofilms and associated pathogens, contributing to the prevention of biofilm-associated nosocomial infections.},
}
@article {pmid35384170,
year = {2022},
author = {Ahmed, HA and Ibrahim, EHS and Abdelhaliem, E and Elariny, EYT},
title = {Biotyping, virulotyping and biofilm formation ability of ESBL-Klebsiella pneumoniae isolates from nosocomial infections.},
journal = {Journal of applied microbiology},
volume = {132},
number = {6},
pages = {4555-4568},
doi = {10.1111/jam.15563},
pmid = {35384170},
issn = {1365-2672},
abstract = {The aim of this study was to investigate the frequency, molecular characterization, virulence genes, resistance genes and antimicrobial profile of nosocomial extended spectrum beta lactamase producing Klebsiella species. A total of 22 (12.2%) K. pneumoniae strains were isolated from 180 clinical samples collected from hospitalized patients in Egypt. K. pneumoniae biotypes were B1 (72.8%), B3 (13.6%) and B4 (13.6%). The isolates were classified for the capsular serotypes, 86.4% (20/22) were of K1 serotype, while only two isolates (13.64%) were of K2 serotype. Hypermucoviscous K. pneumoniae isolates accounted for 68.2%. Biofilm formation ability of K. pneumoniae was determined by microtitre plate method. The majority of the isolates (40.9%) were moderate biofilm producers, while 27.3% were strong biofilm producers. All K. pneumoniae strains were positive for fimH and traT genes, while magA was identified in only 63.6% of the isolates. The antibiotic susceptibility profile of the isolates (n = 22) was determined by the disc diffusion technique using 23 different antibiotics. Streptomycin and imipenem are the most effective antibiotics against 22 tested K. pneumoniae isolates with sensitivity rates of 63.64% and 54.54% respectively. All tested K. pneumoniae isolates showed high resistance to amoxicillin∕clavulanate (100%), cefuroxime (100%) and ceftazidime (95.45%). Extended spectrum beta lactamases (ESBL) production and the presence of ESBL-related genes were tested in the isolates. All the isolates tested positive for blaVIM, NDM1 and blaTEM, while only 81.8 %tested positive for the blaSHV gene. Increasing antimicrobial resistance in K. pneumoniae causing nosocomial infections limits the use of antimicrobial agents for treatment. Furthermore, the spread of biofilm, multiple drug resistant and ESBL-producing K. pneumoniae isolates is a public threat for hospitalized patients.},
}
@article {pmid35383959,
year = {2022},
author = {Saavedra, FM and Pelepenko, LE and Boyle, WS and Zhang, A and Staley, C and Herzberg, MC and Marciano, MA and Lima, BP},
title = {In vitro physicochemical characterization of five root canal sealers and their influence on an ex vivo oral multi-species biofilm community.},
journal = {International endodontic journal},
volume = {},
number = {},
pages = {},
doi = {10.1111/iej.13742},
pmid = {35383959},
issn = {1365-2591},
support = {K08 DE027705/DE/NIDCR NIH HHS/United States ; K08DE027705/DE/NIDCR NIH HHS/United States ; R01DE025618/DE/NIDCR NIH HHS/United States ; R90DE023058/DE/NIDCR NIH HHS/United States ; },
abstract = {AIM: To evaluate the physicochemical properties of five root canal sealers and assess their effect on an ex vivo dental plaque-derived polymicrobial community.<br><br>METHODOLOGY: Dental plaque-derived microbial communities were exposed to the sealers (AH Plus [AHP], GuttaFlow Bioseal [GFB], Endoseal MTA [ESM], Bio-C sealer [BCS] and BioRoot RCS [BRR]) for 3, 6 and 18 h. The sealers' effect on the biofilm biomass and metabolic activity was quantified using crystal violet (CV) staining and MTT assay, respectively. Biofilm community composition and morphology were assessed by denaturing gradient gel electrophoresis (DGGE), 16S rRNA sequencing and scanning electron microscopy. The ISO6876:2012 specifications were followed to determine the setting time, radiopacity, flowability and solubility. Obturated acrylic teeth were used to assess the sealers' effect on pH. Surface chemical characterization was performed using SEM with coupled energy-dispersive spectroscopy. Data normality was assessed using the Shapiro-Wilk test. One-way anova and Tukey's tests were used to analyze data from setting time, radiopacity, flowability and solubility. Two-way anova and Dunnett's tests were used for the data analysis from CV, MTT and pH. 16S rRNA sequencing data were analyzed for alpha (Shannon index and Chao analysis) and beta diversity (Bray-Curtis dissimilarities). Differences in community composition were evaluated by analysis of similarity (p < .05).<br><br>RESULTS: The sealers significantly influenced microbial community composition and morphology. All sealers complied with ISO6876:2012 requirements for setting time, radiopacity and flowability. Although only AHP effectively reduced the biofilm biomass, all sealers, except BRR, reduced biofilm metabolic activity.<br><br>CONCLUSION: Despite adequate physical properties, none of the sealers tested prevented biofilm growth. Significant changes in community composition were observed. If observed in vivo, these changes could affect intracanal microbial survival, pathogenicity and treatment outcomes.},
}
@article {pmid35381282,
year = {2022},
author = {Wang, B and Wei, PW and Yao, Y and Song, CR and Wang, X and Yang, YX and Long, YH and Yang, SW and Hu, Y and Gai, ZC and Wu, JW and Liu, HM},
title = {Functional and expression characteristics identification of Phormicins, novel AMPs from Musca domestica with anti-MRSA biofilm activity, in response to different stimuli.},
journal = {International journal of biological macromolecules},
volume = {209},
number = {Pt A},
pages = {299-314},
doi = {10.1016/j.ijbiomac.2022.03.204},
pmid = {35381282},
issn = {1879-0003},
mesh = {Animals ; Anti-Bacterial Agents/chemistry/pharmacology ; Antimicrobial Peptides ; Biofilms ; *Houseflies/genetics ; Microbial Sensitivity Tests ; },
abstract = {Antibiotic-resistant bacteria (including MRSA) in the clinic pose a growing threat to public health, and antimicrobial peptides (AMPs) have great potential as efficient treatment alternatives. Houseflies have evolved over long periods in complex, dirty environments, developing a special immune system to overcome challenges in harmful environments. AMPs are key innate immune molecules. Herein, two differentially expressed AMPs, Phormicins A and B, were identified by screening transcriptomic changes in response to microbial stimulation. Structural mimic assays indicated that these AMPs exhibited functional divergence due to their C-terminal features. Expression analysis showed that they had different expression patterns. Phormicin B had higher constitutive expression than Phormicin A. However, Phormicin B was sharply downregulated, whereas Phormicin A was highly upregulated, after microbial stimulation. The MIC, MBC and time-growth curves showed the antibacterial spectrum of these peptides. Crystal violet staining and SEM showed that Phormicin D inhibited MRSA biofilm formation. TEM suggested that Phormicin D disrupted the MRSA cell membrane. Furthermore, Phormicin D inhibited biofilm formation by downregulating the expression of biofilm-related genes, including altE and embp. Therefore, housefly Phormicins were functionally characterized as having differential expression patterns and antibacterial &amp; antibiofilm activities. This study provides a new potential peptide for clinical MRSA therapy.},
}
@article {pmid35381253,
year = {2022},
author = {Liu, M and Meng, P and Chen, G and Guan, Y and Liu, G},
title = {Correlation of structural extracellular polymeric substances in the mesh biofilms with solids retention time and biofilm hydraulic resistance in dynamic membrane bioreactors.},
journal = {The Science of the total environment},
volume = {832},
number = {},
pages = {155000},
doi = {10.1016/j.scitotenv.2022.155000},
pmid = {35381253},
issn = {1879-1026},
abstract = {Dynamic membrane bioreactor (DMBR), which mainly relied on the in-situ formed biofilms on support materials with large aperture (e.g., nylon mesh) to separate fine particles in wastewater, has attracted a lot of attentions due to low cost. The filtration performance of DMBR is mainly determined by the structure and hydraulic resistance of biofilms formed on the mesh. Therefore, understanding the correlation of operation conditions with mesh biofilm compositions and permeability are critically important for optimizing DMBR operation. In present study, how structural extracellular polymeric substances, including alginate-like extracellular polysaccharide (ALE) and amyloid-like protein (AP), in mesh biofilms correlate to solids retention time (SRT) and biofilm structures was explored in DMBRs. At 5d-SRT, compact and gel-like mesh biofilms were formed with a high specific filtration resistance (SFR) of 459 × 109 m/g, while at 40d-SRT porous mesh biofilms were developed with a low SFR of 24 × 109 m/g. Consequently, the 5d-SRT MBR experienced more rapid rise in transmembrane pressure. Further studies found that the 5d-SRT mesh biofilms had a higher AP content, which was positively correlated to biofilm hydraulic resistance. On the contrary, the 40d-SRT mesh biofilms contained a higher content of ALE, suggesting that ALE was negatively correlated to biofilm hydraulic resistance. Therefore, AP instead of ALE likely played a more important role in the formation of compact and gel-like mesh biofilms.},
}
@article {pmid35380298,
year = {2022},
author = {Henagamage, AP and Peries, CM and Seneviratne, G},
title = {Fungal-bacterial biofilm mediated heavy metal rhizo-remediation.},
journal = {World journal of microbiology &amp; biotechnology},
volume = {38},
number = {5},
pages = {85},
pmid = {35380298},
issn = {1573-0972},
mesh = {Bacteria ; Biodegradation, Environmental ; Biofilms ; Fungi ; *Metals, Heavy/toxicity ; Soil ; *Soil Pollutants/analysis ; },
abstract = {Heavy metal pollution due to excessive use of chemical fertilizers (CF) causes major damage to the environment. Microbial biofilms, closely associated with the rhizosphere can remediate heavy metal-contaminated soil by reducing plant toxicity. Thus, this study was undertaken to examine the remedial effects of microbial biofilms against contaminated heavy metals. Fungi and bacteria isolated from soil were screened for their tolerance against Cd2+, Pb2+, and Zn2+. Three bacterial and two fungal isolates were selected upon the tolerance index (TI) percentage. Fungal-bacterial biofilms (FBBs) were developed with the most tolerant isolates and were further screened for their bioremediation capabilities against heavy metals. The best biofilm was evaluated for its rhizoremediation capability with different CF combinations using a pot experiment conducted under greenhouse conditions with potatoes. Significantly (P < 0.05), the highest metal removal percentage was observed in Trichoderma harzianum and Bacillus subtilis biofilm under in situ conditions. When compared to the 100% recommended CF, the biofilm with 50% of the recommended CF (50CB) significantly (P < 0.05) reduced soil available Pb2+ by 77%, Cd2+ by 78% and Zn2+ by 62%. In comparison to initial soil, it was 73%, 76%, and 57% lower of Pb2+, Cd2+, and Zn2+, respectively. In addition, 50CB treatment significantly (P < 0.05) reduced the metal penetration into the tuber tissues in comparison with 100 C. Thus, the function of the developed FBB with T. harzianum-B. subtilis can be used as a potential solution to remediate soil polluted with Pb2+ Cd2+ and Zn2+ metal contaminants.},
}
@article {pmid35379908,
year = {2022},
author = {Haque, MM and Biswas, MS and Mosharaf, MK and Haque, MA and Islam, MS and Nahar, K and Islam, MM and Shozib, HB and Islam, MM and Ferdous-E-Elahi, },
title = {Halotolerant biofilm-producing rhizobacteria mitigate seawater-induced salt stress and promote growth of tomato.},
journal = {Scientific reports},
volume = {12},
number = {1},
pages = {5599},
pmid = {35379908},
issn = {2045-2322},
mesh = {*Alphaproteobacteria ; Biofilms ; *Lycopersicon esculentum/microbiology ; Salt Stress ; Seawater ; },
abstract = {Biofilm-producing rhizobacteria (BPR) enhance productivity and mitigate abiotic stresses in plants. This study showed that 21 out of 65 halotolerant rhizobacteria could build biofilms. The components of the biofilm matrices i.e., extracellular polymeric substances (EPS) are proteins, curli, nanocelloluse, nucleic acids, lipids, and peptidoglycans. Various functional groups including carbonyl, carboxyl, amino, hydroxyl, and phosphate were identified. Positions of these groups were shifted by application of 5% NaCl, suggesting Na+ biosorption. By sequencing, Glutamicibacter arilaitensis (ESK1, ESM4 and ESM7), G. nicotianae (ESK19, ESM8 and ESM16), Enterobacter ludwigii (ESK15, ESK17, ESM2 and ESM17), E. cloacae (ESM5 and ESM12), Exiguobacterium acetylicum (ESM24 and ESM25), Staphylococcus saprophyticus ESK6, Leclercia adecarboxylata ESK12, Pseudomonas poae ESK16, Bacillus subtilis ESM14, and P. putida ESM17 were identified. These rhizobacteria exhibited numerous plant growth-promoting (PGP) activities including producing IAA, ACC deaminase, and siderophores, and solubilizing phosphate. Under non-stress, bacterized plants increased biomass accumulation (8-23.2% roots and 23-49.4% shoots), while under seawater-induced salt stress only ESK12, ESM4, ESM12, and ESM14 enhanced biomass production (5.8-52.9% roots and 8.8-33.4% shoots). Bacterized plants induced antioxidant defense system (19.5-142% catalase and 12.3-24.2% DPPH radical scavenging activity), retained a greater relative water content (17-124%), showed lesser membrane injuries (19.9-26.5%), and a reduced Na+ (6-24% in roots) and increased K+/Na+ ratio (78.8 and 103% in roots by ESK12 and ESM24, respectively) than the non-bacterized plants in saline conditions. Thus, native halotolerant BPR can be utilized as ameliorators of salt stress.},
}
@article {pmid35379855,
year = {2022},
author = {Karched, M and Bhardwaj, RG and Qudeimat, M and Al-Khabbaz, A and Ellepola, A},
title = {Proteomic analysis of the periodontal pathogen Prevotella intermedia secretomes in biofilm and planktonic lifestyles.},
journal = {Scientific reports},
volume = {12},
number = {1},
pages = {5636},
pmid = {35379855},
issn = {2045-2322},
mesh = {Biofilms ; *Plankton/genetics ; Prevotella intermedia ; *Proteomics ; Secretome ; },
abstract = {Prevotella intermedia is an important species associated with periodontitis. Despite the remarkable clinical significance, little is known about the molecular basis for its virulence. The aim of this study was to characterize the secretome of P. intermedia in biofilm and planktonic life mode. The biofilm secretome showed 109 proteins while the planktonic secretome showed 136 proteins. The biofilm and the planktonic secretomes contained 17 and 33 signal-peptide bearing proteins, 13 and 18 lipoproteins, respectively. Superoxide reductase, sensor histidine kinase, C40 family peptidase, elongation factor Tu, threonine synthase etc. were unique to biofilm. Of the ~ 30 proteins with predicted virulence potential from biofilm and planktonic secretomes, only 6 were common between the two groups, implying large differences between biofilm and planktonic modes of P. intermedia. From Gene Ontology biofilm secretome displayed a markedly higher percent proteins compared to planktonic secretome in terms of cellular amino acid metabolic process, nitrogen compound metabolic process etc. Inflammatory cytokine profile analysis revealed that only the biofilm secretome, not the planktonic one, induced important cytokines such as MIP-1α/MIP-1β, IL-1β, and IL-8. In conclusion, the revealed differences in the protein profiles of P. intermedia biofilm and planktonic secretomes may trigger further questions about molecular mechanisms how this species exerts its virulence potential in the oral cavity.},
}
@article {pmid35379438,
year = {2022},
author = {McCaughey, CS and Trebino, MA and Yildiz, FH and Sanchez, LM},
title = {Utilizing imaging mass spectrometry to analyze microbial biofilm chemical responses to exogenous compounds.},
journal = {Methods in enzymology},
volume = {665},
number = {},
pages = {281-304},
pmid = {35379438},
issn = {1557-7988},
support = {R01 AI102584/AI/NIAID NIH HHS/United States ; R01 CA240423/CA/NCI NIH HHS/United States ; R01 GM125943/GM/NIGMS NIH HHS/United States ; },
mesh = {*Biofilms ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods ; },
abstract = {Matrix-assisted laser desorption/ionization imaging mass spectrometry (MALDI-IMS) is an appealing label-free method for imaging biological samples which focuses on the spatial distribution of chemical signals. This approach has been used to study the chemical ecology of microbes and can be applied to study the chemical responses of microbes to treatment with exogenous compounds. Specific conjugated cholic acids such as taurocholic acid (TCA), have been shown to inhibit biofilm formation in the enteric pathogen Vibrio cholerae and MALDI-IMS can be used to directly observe the chemical responses of V. cholerae biofilm colonies to treatment with TCA. A major challenge of MALDI-IMS is optimizing the sample preparation and drying for a particular growth condition and microbial strain. Here we demonstrate how V. cholerae is cultured and prepared for MALDI-IMS analysis and highlight critical steps to ensure proper sample adherence to a MALDI target plate and maintain spatial distributions when applying this technique to any microbial strain. We additionally show how to use both manual interrogation and statistical analyses of MALDI-IMS data to establish the adequacy of the sample preparation protocol. This protocol can serve as a guideline for the development of sample preparation techniques and the acquisition of high quality MALDI-IMS data.},
}
@article {pmid35379435,
year = {2022},
author = {Eddenden, A and Nitz, M},
title = {Applications of an inactive Dispersin B probe to monitor biofilm polysaccharide production.},
journal = {Methods in enzymology},
volume = {665},
number = {},
pages = {209-231},
doi = {10.1016/bs.mie.2021.11.006},
pmid = {35379435},
issn = {1557-7988},
mesh = {Acetylglucosamine ; *Bacterial Proteins/genetics/metabolism ; *Biofilms ; Catalytic Domain ; Polysaccharides ; },
abstract = {Bacterial biofilms consist of surface-attached communities that secrete polymeric substances to form a biofilm matrix, generating a local microenvironment which helps protect from external factors. One such matrix component produced by a diverse list of microorganisms is the polysaccharide poly-β-1,6-N-acetylglucosamine (PNAG). Dispersin B is a PNAG-specific glycosyl hydrolase, which by leveraging its unique specificity, can be used to design a macromolecular fluorescent PNAG binding probe. An active site mutant of Dispersin B was fused to a fluorescent protein, to generate a probe that bound PNAG but did not hydrolyze its polysaccharide target. The ease and versatility of this strategy has made it possible to study PNAG in the context of maturing biofilms, as the probe tends to sequester in regions of high PNAG density. In this chapter, typical workflows from probe construction to cell-binding and imaging experiments are described.},
}
@article {pmid35378281,
year = {2022},
author = {Maurya, A and Kumar, R and Yadav, P and Singh, A and Yadav, A and Chowdhary, P and Raj, A},
title = {Biofilm formation and extracellular polymeric substance (EPS) production by Bacillus haynesii and influence of hexavalent chromium.},
journal = {Bioresource technology},
volume = {352},
number = {},
pages = {127109},
doi = {10.1016/j.biortech.2022.127109},
pmid = {35378281},
issn = {1873-2976},
mesh = {Bacillus ; Biofilms ; *Chromium ; *Extracellular Polymeric Substance Matrix ; },
abstract = {Biofilm-forming bacteria play a key role in the removal of heavy metals including hexavalent chromium [Cr(VI)] from contaminated sites. In this study, biofilm-forming B. haynesii was examined for extracellular polymeric substances (EPS) production and hexavalent chromium [Cr(VI)] reduction potential. Exposure of B. haynesii with Cr(VI) (12.5-100 mg L-1) for 48 h enhanced pellicle dry weight (20-24%), cell-size (5.1-23.2%) and cell granularity (8.5-19.2%). Also, EPS production was increased by 10-35% by promoting the synthesis of protein (94-119%) and polysaccharide (2-33%) components in EPS. Further, the reduction (27.7 %) and distribution (15.87%) of Cr(VI) were mainly mediated by EPS than the other cellular fractions. Findings of the study suggest that the EPS from B. haynesii was efficiently reduced to Cr(VI) present in aqueous medium and the potential of the organism can be further explored for the mitigation of Cr(VI) contamination.},
}
@article {pmid35378158,
year = {2022},
author = {Xu, D and Xiao, J and Jiang, D and Liu, Y and Gou, Z and Li, J and Shi, M and Wang, X and Guo, Y and Ma, L and Yin, H and Guo, L and Zhu, C and Zhang, Y and Guo, H},
title = {Inhibitory effects of a water-soluble jujube polysaccharide against biofilm-forming oral pathogenic bacteria.},
journal = {International journal of biological macromolecules},
volume = {208},
number = {},
pages = {1046-1062},
doi = {10.1016/j.ijbiomac.2022.03.196},
pmid = {35378158},
issn = {1879-0003},
mesh = {Anti-Bacterial Agents/pharmacology ; Biofilms ; *Dental Caries ; *Microbiota ; Polysaccharides/chemistry/pharmacology ; Spectroscopy, Fourier Transform Infrared ; Streptococcus mutans ; Water/pharmacology ; *Ziziphus/chemistry ; },
abstract = {Oral diseases caused by infectious pathogens raises significant concerns in public health. In the light of side effects of current antibiotics therapy and growing drug resistance of pathogenic bacteria, natural products have become attractive alternatives for antibiotics agents in dental practice. This current study investigated the effects of polysaccharides extracted from Zizyphus jujuba Mill. on three major oral biofilm-forming pathogenic bacteria including caries-inducing Streptococcus mutans, lesions-causing MRSA, and periodontitis-related Porphyromonas gingivalis, as well as general oral microbiota. Our results demonstrated that jujube polysaccharide prepared in this study was mainly composed by galacturonic acid with an average molecular weight 242 kDa, which were further characterized for structural features by FT-IR spectra and NMR spectroscopy analysis. This jujube polysaccharide was shown to exhibit remarkable inhibitory effects against all the tested oral bacterial pathogens through various mechanisms including growth inhibition, biofilm prevention and disruption, intervention of bacterial infection (adhesion and invasion), attenuation of cytotoxicity, modulation of excessive inflammatory response of LPS-stimulated and MRSA-infected macrophages as well as positive regulation of oral microbiota. The present study paves the way to explore jujube polysaccharides for the prevention and treatment of oral infectious diseases. Graphic Abstract.},
}
@article {pmid35377868,
year = {2022},
author = {Polizzi, B and Fanesi, A and Lopes, F and Ribot, M and Bernard, O},
title = {Understanding photosynthetic biofilm productivity and structure through 2D simulation.},
journal = {PLoS computational biology},
volume = {18},
number = {4},
pages = {e1009904},
pmid = {35377868},
issn = {1553-7358},
mesh = {Biofilms ; Carbon ; Computer Simulation ; *Microalgae ; *Photosynthesis ; },
abstract = {We present a spatial model describing the growth of a photosynthetic microalgae biofilm. In this 2D-model we consider photosynthesis, cell carbon accumulation, extracellular matrix excretion, and mortality. The rate of each of these mechanisms is given by kinetic laws regulated by light, nitrate, oxygen and inorganic carbon. The model is based on mixture theory and the behaviour of each component is defined on one hand by mass conservation, which takes into account biological features of the system, and on the other hand by conservation of momentum, which expresses the physical properties of the components. The model simulates the biofilm structural dynamics following an initial colonization phase. It shows that a 75 μm thick active region drives the biofilm development. We then determine the optimal harvesting period and biofilm height which maximize productivity. Finally, different harvesting patterns are tested and their effect on biofilm structure are discussed. The optimal strategy differs whether the objective is to recover the total biofilm or just the algal biomass.},
}
@article {pmid35373364,
year = {2022},
author = {Ghosh, S and Nag, M and Lahiri, D and Sarkar, T and Pati, S and Joshi, S and Ray, RR},
title = {New holistic approach for the management of biofilm-associated infections by myco-metabolites.},
journal = {Journal of basic microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1002/jobm.202200047},
pmid = {35373364},
issn = {1521-4028},
abstract = {Biofilm-associated infections have increased excessively over the recent years due to the increased population having impaired immune systems or as a result of certain medical conditions like transplantation, cancer, and any other chronic ailments. The abrupt enhancement of antibiotic resistance and enhanced utilization of biomedical devices offer new opportunities for microbial colonization leading to the development of microbial biofilms. Total eradication of recalcitrant microbial biofilms demands the adoption of a holistic approach and since the fungal metabolites enriched with bioactive compounds show efficacy in inhibiting the multiple factors behind biofilm formation, the anti-biofilm activities of fungal metabolites need to be appraised. Being effective in preventing various steps of biofilm formation, including inhibition of surface adhesion and cell-to-cell communication through quorum quenching, blocking of quorum sensing receptors, and enzymes involved in microbial cell wall biosynthesis, targeting the virulence factors and finally killing of biofilm bound individual cells; myco-metabolites are found effective as a potent holistic anti-biofilm agent. The wide spectrum of bioactive substances of fungi and their anti-biofilm activities against different pathogens and their multitarget characteristics are very promising in the field of treating biofilm infections.},
}
@article {pmid35371582,
year = {2022},
author = {Sagar, PK and Sharma, P and Singh, R},
title = {Inhibition of Quorum Sensing Regulated Virulence Factors and Biofilm Formation by Eucalyptus globulus against Multidrug-Resistant Pseudomonas aeruginosa.},
journal = {Journal of pharmacopuncture},
volume = {25},
number = {1},
pages = {37-45},
pmid = {35371582},
issn = {2093-6966},
abstract = {Objectives: The quorum-sensing-inhibitory and anti-biofilm activities of the methanol extract of E. globulus leaves were determined against clinically isolated multidrug-resistant Pseudomonas aeruginosa.<br><br>Methods: The preliminary anti-quorum-sensing (AQS) activity of eucalyptus was investigated against a biosensor strain Chromobacterium violaceum ATCC 12472 (CV12472) by using the agar well diffusion method. The effect of sub-minimum inhibitory concentrations (sub-MICs) of the methanol extract of eucalyptus on different quorum-sensing-regulated virulence factors, such as swarming motility, pyocyanin pigment, exopolysaccharide (EPS), and biofilm formation, against clinical isolates (CIs 2, 3, and 4) and reference PA01 of Pseudomonas aeruginosa were determined using the swarm diameter (mm)-measurement method, chloroform extraction method, phenol (5%)-sulphuric acid (concentrated) method, and the microtiter plate assay respectively, and the inhibition (%) in formation were calculated.<br><br>Results: The preliminary AQS activity (violacein pigment inhibition) of eucalyptus was confirmed against Chromobacterium violaceum ATCC 12472 (CV12472). The eucalyptus extract also showed concentration-dependent inhibition (%) of swarming motility, pyocyanin pigment, EPS, and biofilm formation in different CIs and PA01 of P. aeruginosa.<br><br>Conclusion: Our results revealed the effectiveness of the E. globulus extract for the regulation of quorum-sensing-dependent virulence factors and biofilm formation at a reduced dose (sub-MICs) and suggest that E. globulus may be a therapeutic agent for curing and controlling bacterial infection and thereby reducing the possibility of resistance development in pathogenic strains.},
}
@article {pmid35370181,
year = {2022},
author = {Koike, M and Mitchell, RJ and Horie, T and Hummel, SK and Okabe, T},
title = {Biofilm accumulation on additive manufactured Ti-6Al-4V alloy surfaces.},
journal = {Journal of oral science},
volume = {64},
number = {2},
pages = {139-144},
doi = {10.2334/josnusd.21-0521},
pmid = {35370181},
issn = {1880-4926},
mesh = {*Alloys ; Biofilms ; Dental Alloys ; *Titanium ; },
abstract = {PURPOSE: This study investigated whether additive manufactured (AM) surfaces inhibit accumulation of bacterial biofilm on the surfaces of Ti-6Al-4V alloy dental implants. Bacterial biofilms are thought to cause peri-implant disease, which develops in mucosa surrounding titanium (Ti) and Ti alloy dental implants and can lead to bone loss and implant failure.<br><br>METHODS: Accumulation of a Streptococcus mutans (ATCC 25175) biofilm on Ti-6Al-4V alloy was compared in relation to fabrication method, ie, AM using electron beam melting (EBM) or laser beam melting (LBM). Conventional lost-wax casting was used as positive control, and Teflon was used as negative control. Biofilm accumulation on the alloys and negative control (each n = 10) was conducted at 37°C under anaerobic conditions. After 4 h, the number of metabolically active S. mutans bacteria adhering to the alloy was determined with a bioluminescence assay.<br><br>RESULTS: The quantitative roughness values of the specimens, before exposure to bacteria, ranked EBM > LBM > cast > Teflon.<br><br>CONCLUSION: The amount of biofilm accumulation on the investigated AM metals and cast metal controls did not significantly differ.},
}
@article {pmid35369599,
year = {2022},
author = {Ibrahim, ES and Arafa, AA and Dorgam, SM and Eid, RH and Atta, NS and El-Dabae, WH and Gaber Sadek, E},
title = {Molecular characterization of genes responsible for biofilm formation in Staphylococcus aureus isolated from mastitic cows.},
journal = {Veterinary world},
volume = {15},
number = {1},
pages = {205-212},
pmid = {35369599},
issn = {0972-8988},
abstract = {Background and Aim: Mastitis is considered a significant disease of lactating animals. There are new attitudes for recognizing genes responsible for causing this disease to overcome and change the manipulation of this problem. This study aimed to isolate and identify Staphylococcus aureus strains from mastitic bovine animals and detect some specific biofilm-forming genes (icaA, icaD, and biofilm-associated protein [bap] genes clfA, fnbA, agrI, agrII, agrIII, agrIV, and cna).<br><br>Materials and Methods: A total of 121 mastitic milk samples were analyzed using biochemical tests (catalase test, oxidative-fermentative test, and coagulase test) and Gram stain. Multiplex polymerase chain reaction was applied to characterize biofilm genes (icaA, icaD, bap, clfA, and fnbA) in addition to (agrI, agrII, agrIII, agrIV, and cna).<br><br>Results: Among the 121 milk samples, 35 staphylococci isolates were derived with an incidence of 28.92% (35/121); among them, 19 are coagulase positive. Ninety percent of the isolates had ica genes (icaA and icaD) while bap gene was not recognized in any isolate. In addition, the incidence of fnbA, can, and clfA was 89.5% each. The prevalence of agr specific groups (agrI, agrII, agrIII, and agrIV) was 78.9%, 52.6%, 10.5%, and 15.8%, respectively.<br><br>Conclusion: This study concluded that S. aureus has variant mechanisms of pathogenicity to form biofilm devoid of carrying a specific gene.},
}
@article {pmid35369527,
year = {2022},
author = {Wang, B and Song, CR and Zhang, QY and Wei, PW and Wang, X and Long, YH and Yang, YX and Liao, SG and Liu, HM and Xu, GB},
title = {The Fusaric Acid Derivative qy17 Inhibits Staphylococcus haemolyticus by Disrupting Biofilm Formation and the Stress Response via Altered Gene Expression.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {822148},
pmid = {35369527},
issn = {1664-302X},
abstract = {Staphylococcus haemolyticus (S. haemolyticus) is the second most commonly isolated coagulase-negative staphylococcus (CoNS) in patients with hospital-acquired infections. It can produce phenol-soluble modulin (PSM) toxins and form biofilms. Compared with the wealth of information on Staphylococcus aureus and Staphylococcus epidermidis, very little is known about S. haemolyticus. There is an urgent need to find an effective preparation to combat the harm caused by S. haemolyticus infection. Chinese herbs have been utilized to cure inflammation and infectious diseases and have a long history of anticancer function in China. Here, we modified fusaric acid characterized from the metabolites of Gibberella intermedia, an endophyte previously isolated from Polygonum capitatum. This study shows that fusaric acid analogs (qy17 and qy20) have strong antibacterial activity against S. haemolyticus. In addition, crystal violet analyses and scanning electron microscopy observations demonstrated that qy17 inhibited biofilm formation and disrupted mature biofilms of S. haemolyticus in a dose-dependent manner. Additionally, it reduced the number of live bacteria inside the biofilm. Furthermore, the antibiofilm function of qy17 was achieved by downregulating transcription factors (sigB), transpeptidase genes (srtA), and bacterial surface proteins (ebp, fbp) and upregulating biofilm-related genes and the density-sensing system (agrB). To further elucidate the bacteriostatic mechanism, transcriptomic analysis was carried out. The following antibacterial mechanisms were uncovered: (i) the inhibition of heat shock (clpB, groES, groL, grpE, dnaK, dnaJ)-, oxidative stress (aphC)- and biotin response (bioB)-related gene expression, which resulted in S. haemolyticus being unable to compensate for various stress conditions, thereby affecting bacterial growth; and (ii) a reduction in the expression of PSM-beta (PSMβ1, PSMβ2, PSMβ3) toxin- and Clp protease (clpP, clpX)-related genes. These findings could have major implications for the treatment of diseases caused by S. haemolyticus infections. Our research reveals for the first time that fusaric acid derivatives inhibit the expression of biofilm formation-related effector and virulence genes of S. haemolyticus. These findings provide new potential drug candidates for hospital-acquired infections caused by S. haemolyticus.},
}
@article {pmid35369456,
year = {2022},
author = {Chen, K and Gao, Y and Li, L and Zhang, W and Li, J and Zhou, Z and He, H and Chen, Z and Liao, M and Zhang, J},
title = {Increased Drug Resistance and Biofilm Formation Ability in ST34-Type Salmonella Typhimurium Exhibiting Multicellular Behavior in China.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {876500},
pmid = {35369456},
issn = {1664-302X},
abstract = {Salmonella Typhimurium is an important food-borne pathogen. In this paper, multicellular behavior and associated characteristics of S. Typhimurium isolated from human and animal source food were studied. All the S. Typhimurium strains exhibiting multicellular behavior (100%) belonged to the ST34 type. In addition, most of the ST34-type multicellular behavior S. Typhimurium strains had a human origin (69.11%) and 98% of the ST34-type multicellular behavior strains exhibited strong biofilm formation capacity, which was much higher than that of non-multicellular behavior strains (7%, P < 0.01). Antibiotic resistance in ST34-type multicellular behavior strains was significantly higher than in strains with non-multicellular behavior for most conventional drugs (P < 0.05); notably, Polymyxin B (8%) and Imipenem (1%) resistances were also observed in the ST34-type strains. Furthermore, all the ST34-type multicellular behavior strains (100%) exhibited Multiple Drug Resistance (resistance to ≥3antibiotics), which was much higher than that of the non-multicellular behavior strains (P < 0.05). Consistent with the drug-resistant phenotype, the carrying rates of most drug-resistant genes in ST34-type multicellular behavior strains were higher than that those in non-multicellular behavior strains (P < 0.05). Therefore, this study revealed the emergence of a prevalent ST34-type multicellular behavior S. Typhimurium strains with increased biofilm formation ability and drug resistance rate, which poses a threat to public health safety, and highlights the need for comprehensive monitoring of the strains.},
}
@article {pmid35369450,
year = {2022},
author = {Zhao, D and Wang, H and Li, Z and Han, S and Han, C and Liu, A},
title = {LC_Glucose-Inhibited Division Protein Is Required for Motility, Biofilm Formation, and Stress Response in Lysobacter capsici X2-3.},
journal = {Frontiers in microbiology},
volume = {13},
number = {},
pages = {840792},
pmid = {35369450},
issn = {1664-302X},
abstract = {Glucose-inhibited division protein (GidA) plays a critical role in the growth, stress response, and virulence of bacteria. However, how gidA may affect plant growth-promoting bacteria (PGPB) is still not clear. Our study aimed to describe the regulatory function of the gidA gene in Lysobacter capsici, which produces a variety of lytic enzymes and novel antibiotics. Here, we generated an LC_GidA mutant, MT16, and an LC_GidA complemented strain, Com-16, by plasmid integration. The deletion of LC_GidA resulted in an attenuation of the bacterial growth rate, motility, and biofilm formation of L. capsici. Root colonization assays demonstrated that the LC_GidA mutant showed reduced colonization of wheat roots. In addition, disruption of LC_GidA showed a clear diminution of survival in the presence of high temperature, high salt, and different pH conditions. The downregulated expression of genes related to DNA replication, cell division, motility, and biofilm formation was further validated by real-time quantitative PCR (RT-qPCR). Together, understanding the regulatory function of GidA is helpful for improving the biocontrol of crop diseases and has strong potential for biological applications.},
}
@article {pmid35368854,
year = {2022},
author = {He, Z and Jiang, W and Jiang, Y and Dong, J and Song, Z and Xu, J and Zhou, W},
title = {Anti-biofilm activities of coumarin as quorum sensing inhibitor for Porphyromonas gingivalis.},
journal = {Journal of oral microbiology},
volume = {14},
number = {1},
pages = {2055523},
pmid = {35368854},
issn = {2000-2297},
abstract = {Porphyromonas gingivalis is a keystone pathogen in periodontitis, a biofilm-mediated infection disease. This research aimed to investigate the effect of coumarin on P. gingivalis biofilm formation. We detected the antimicrobial effect on P. gingivalis planktonic growth, observed membrane structure and morphological change by TEM, and quantified membrane permeability by calcein-AM staining. The cell surface hydrophobicity, aggregation, and attachment were assessed. We also investigated different sub-MIC concentrations of coumarin on biofilm formation, and observed biofilm structureby confocal laser scanning microscopy. The biofilm-related gene expression was evaluated using real-time PCR. The results showed that coumarin inhibited P. gingivalis growth and damaged the cell morphology above 400 μM concentration. Coumarin did not affect cell surface hydrophobicity, aggregation, attachment, and the early stage of biofilm formation at sub-MIC concentrations. Still, it exhibited anti-biofilm effects for the late-stage and pre-formed biofilms dispersion. The biofilms after coumarin treatment became interspersed, and biofilm-related gene expression was downregulated. Coumarin also inhibited AI-2 activity and interacted with the HmuY protein by molecular docking analysis. Our research demonstrated that coumarin inhibited P. gingivalis biofilm formation through a quorum sensing system.},
}
@article {pmid35368312,
year = {2022},
author = {Muchova, M and Balacco, DL and Grant, MM and Chapple, ILC and Kuehne, SA and Hirschfeld, J},
title = {Fusobacterium nucleatum Subspecies Differ in Biofilm Forming Ability in vitro.},
journal = {Frontiers in oral health},
volume = {3},
number = {},
pages = {853618},
pmid = {35368312},
issn = {2673-4842},
abstract = {Development of dysbiosis in complex multispecies bacterial biofilms forming on teeth, known as dental plaque, is one of the factors causing periodontitis. Fusobacterium nucleatum (F. nucleatum) is recognised as a key microorganism in subgingival dental plaque, and is linked to periodontitis as well as colorectal cancer and systemic diseases. Five subspecies of F. nucleatum have been identified: animalis, fusiforme, nucleatum, polymorphum, and vincentii. Differential integration of subspecies into multispecies biofilm models has been reported, however, biofilm forming ability of individual F. nucleatum subspecies is largely unknown. The aim of this study was to determine the single-subspecies biofilm forming abilities of F. nucleatum ATCC type strains. Static single subspecies F. nucleatum biofilms were grown anaerobically for 3 days on untreated or surface-modified (sandblasting, artificial saliva, fibronectin, gelatin, or poly-L-lysine coating) plastic and glass coverslips. Biofilm mass was quantified using crystal violet (CV) staining. Biofilm architecture and thickness were analysed by scanning electron microscopy and confocal laser scanning microscopy. Bioinformatic analysis was performed to identify orthologues of known adhesion proteins in F. nucleatum subspecies. Surface type and treatment significantly influenced single-subspecies biofilm formation. Biofilm formation was overall highest on poly-L-lysine coated surfaces and sandblasted glass surfaces. Biofilm thickness and stability, as well as architecture, varied amongst the subspecies. Interestingly, F. nucleatum ssp. polymorphum did not form a detectable, continuous layer of biofilm on any of the tested substrates. Consistent with limited biofilm forming ability in vitro, F. nucleatum ssp. polymorphum showed the least conservation of the adhesion proteins CmpA and Fap2 in silico. Here, we show that biofilm formation by F. nucleatum in vitro is subspecies- and substrate-specific. Additionally, F. nucleatum ssp. polymorphum does not appear to form stable single-subspecies continuous layers of biofilm in vitro. Understanding the differences in F. nucleatum single-subspecies biofilm formation may shed light on multi-species biofilm formation mechanisms and may reveal new virulence factors as novel therapeutic targets for prevention and treatment of F. nucleatum-mediated infections and diseases.},
}
@article {pmid35368183,
year = {2022},
author = {Lee, JW and Lee, SS and Yang, SH and Choe, HS},
title = {Assessment of Bacterial Communities Within the Biofilm of Bladder Calculi in the Neurogenic Bladder Rat Model Following Spinal Cord Injury.},
journal = {International neurourology journal},
volume = {26},
number = {1},
pages = {26-30},
pmid = {35368183},
issn = {2093-4777},
abstract = {PURPOSE: To develop a rat model of bladder calculi in the neurogenic bladder following spinal cord injury (SCI) and assess bacterial communities within the biofilm of bladder calculi using denaturing gradient gel electrophoresis (DGGE).<br><br>METHODS: The silk tied to a small segment of the Teflon IV catheter was implanted through the urethra into the bladder of rats with SCI induced by T9 laminectomy. After 6 months, the rats were sacrificed and their bladder calculi were collected by opening the bladders through the low-midline incision. Genomic DNA was extracted from the biofilm of bladder calculi followed by DGGE to obtain bacterial DNA. The DNA sequences were compared and analyzed using BLAST (Basic Local Alignment Search Tool) to identify bacteria.<br><br>RESULTS: After placing silk nidus in the bladder for 6 months, all 6 rats developed bladder calculi. According to DGGE analysis, Pseudomonas aeruginosa was the most dominant strain, while Clostridium sp. and Lactobacillus sp. were relatively dominant strains within the biofilm of bladder calculi in the rats with SCI.<br><br>CONCLUSION: DGGE analysis showed various microorganisms in the biofilm of calculi arising from a neurogenic bladder rat model. This research design can be the basis for clinical studies and may be applied to calculi in patients with neurogenic bladder following SCI.},
}
@article {pmid35368079,
year = {2022},
author = {Chaiben, V and Yamada, CH and Telles, JP and de Andrade, AP and Arend, LNVS and Ribeiro, VST and Dantas, LR and Suss, PH and Tuon, FF},
title = {A carbapenem-resistant Acinetobacter baumannii outbreak associated with a polymyxin shortage during the COVID pandemic: an in vitro and biofilm analysis of synergy between meropenem, gentamicin and sulbactam.},
journal = {The Journal of antimicrobial chemotherapy},
volume = {},
number = {},
pages = {},
doi = {10.1093/jac/dkac102},
pmid = {35368079},
issn = {1460-2091},
abstract = {BACKGROUND: During the COVID-19 pandemic, the burden of nosocomial infections caused by MDR pathogens has caused a shortage of polymyxins. Thus, we evaluated the in vitro synergism and antibiofilm activity of antimicrobial combinations and propose a test kit for synergism against carbapenem-resistant Acinetobacter baumannii (CRAB).<br><br>METHODS: Fifty-six CRAB isolates were tested for synergy between meropenem, gentamicin and ampicillin/sulbactam. MICs were determined by broth microdilution. Synergism was tested using chequerboard analysis, followed by a time-kill curve. Additionally, minimum biofilm eradication concentration was determined and the antibiofilm activity of the combinations was evaluated by MTT assay and biomass reduction. A test kit was developed for routine laboratory testing to detect synergism.<br><br>RESULTS: All CRAB isolates were resistant to gentamicin and ampicillin/sulbactam. Chequerboard synergism occurred against 75% of the isolates. Meropenem + ampicillin/sulbactam was the most frequent combination with synergism (69%), followed by ampicillin/sulbactam + gentamicin (64%) and meropenem + gentamicin (51%). All combinations presented only bacteriostatic activity and no bactericidal or antibiofilm effects. The routine laboratory test showed 100% accuracy compared with other in vitro assays.<br><br>CONCLUSIONS: Our study demonstrates the potential role of antibiotic combinations against planktonic bacteria. In vitro synergism is possible and can be an alternative treatment for patients with CRAB infection during a polymyxin shortage.},
}
@article {pmid35367853,
year = {2022},
author = {Melian, C and Bentencourt, E and Castellano, P and Ploper, D and Vignolo, G and Mendoza, LM},
title = {Biofilm genes expression of Listeria monocytogenes exposed to Latilactobacillus curvatus bacteriocins at 10 °C.},
journal = {International journal of food microbiology},
volume = {370},
number = {},
pages = {109648},
doi = {10.1016/j.ijfoodmicro.2022.109648},
pmid = {35367853},
issn = {1879-3460},
mesh = {*Bacteriocins/metabolism ; Biofilms ; Lactobacillus/metabolism ; *Listeria monocytogenes/genetics ; },
}
@article {pmid35367555,
year = {2022},
author = {Lan, J and Ren, Y and Luo, H and Wang, X and Liu, G and Zhang, R},
title = {High current density with spatial distribution of Geobacter in anodic biofilm of the microbial electrolysis desalination and chemical-production cell with enlarged volumetric anode.},
journal = {The Science of the total environment},
volume = {831},
number = {},
pages = {154798},
doi = {10.1016/j.scitotenv.2022.154798},
pmid = {35367555},
issn = {1879-1026},
abstract = {The aim of this study was to establish the relationship between spatial distribution of Geobacter and electric intensity in the microbial electrolysis desalination and chemical-production cell (MEDCC) and to investigate the effect of enlarged volumetric anode on the performance of MEDCC. The MEDCC was constructed with nine carbon brush anodes (length × diameter = 11 cm × 3 cm) as enlarged volumetric anode, and operated by feeding with 1 g/L acetate as substrate and 35 g/L NaCl as artificial seawater under the applied voltages of 1.2-4.5 V. Spatial distribution of Geobacter in the anodic biofilm was determined according to the bacterial community analysis on 27 biofilm samples from the top, middle and bottom layers of anodes (i.e., with distance of 4.5, 10, and 15.5 cm to the cathode, respectively). Results showed that the enlarged volumetric anode significantly improved the performance of MEDCC. The maximum desalination rate and current density reached 338.5 ± 21.8 mg/L∙h and 55.7 ± 3.7 A/m2 in the MEDCC, respectively. The electric intensity values decreased with the distance from the anode to the cathode and formed an uneven distribution in the anode chamber. The samples in the top layer of anodes had the highest average 16S rRNA gene copy number of Geobacter of 1.55 × 107 copies/μL, which was 18 times higher than that in the bottom layer of anodes. A linear relation was established between the spatial distribution of Geobacter and electric intensity (R2 = 0.994-0.999). The electric intensity gradient created the uneven spatial distribution of Geobacter in the biofilms of volumetric anode. Results from this study could be useful to enrich Geobacter in the anodic biofilm thus to improve the performance of MEDCC.},
}
@article {pmid35367266,
year = {2022},
author = {Learbuch, KLG and Smidt, H and van der Wielen, PWJJ},
title = {Water and biofilm in drinking water distribution systems in the Netherlands.},
journal = {The Science of the total environment},
volume = {831},
number = {},
pages = {154940},
doi = {10.1016/j.scitotenv.2022.154940},
pmid = {35367266},
issn = {1879-1026},
abstract = {To keep the high quality of drinking water in the future for non-chlorinated drinking water systems, knowledge about the variables that most strongly affect this quality is necessary in order to know where to focus on and possibly even change aspects of drinking water production and distribution. Therefore, the aim of this study was to investigate which variables (source of drinking water, growth potential and pipe material type) have the biggest influence on bacterial community composition and biomass concentration of drinking water and biofilm in distribution systems. Ten different distribution systems were sampled for water and biofilm, obtained from four different pipe materials, throughout the Netherlands. The distribution systems are supplied either with drinking water produced from groundwater or surface water, and differ in drinking water quality parameters such as the growth potential. We found a significant relationship for growth potential and ATP concentration in water, but for the ATP in the biofilm none of the parameters showed a significant effect. Furthermore, the source of the drinking water and the pipe material did not significantly affect the ATP concentration in water and biofilm. The bacterial composition of in both water and biofilm was significantly different between distribution systems delivering water with low and high growth potential and between drinking water produced from groundwater or surface water. In contrast, the different pipe materials did not significantly affect composition of biofilm-associated communities. We conclude from these results that the growth potential of the treated water best explains the variation in biomass and bacterial composition in water and biofilm of non-chlorinated drinking water distribution systems followed by the drinking water source, whereas pipe materials seem to be of lesser importance.},
}
@article {pmid35366684,
year = {2022},
author = {Bashir, A and Ahmad, T and Farooq, S and Lone, WI and Manzoor, MM and Nalli, Y and Sultan, P and Chaubey, A and Ali, A and Riyaz-Ul-Hassan, S},
title = {A Secondary Metabolite of Cercospora sp., Associated with Rosa damascena Mill., Inhibits Proliferation, Biofilm Production, Ergosterol Synthesis and Other Virulence Factors in Candida albicans.},
journal = {Microbial ecology},
volume = {},
number = {},
pages = {},
pmid = {35366684},
issn = {1432-184X},
abstract = {Here we describe the antimicrobial potential of secondary metabolites, fulvic acid (F.A.) and anhydrofulvic acid (AFA), produced by RDE147, an endophyte of Rosa damascena Mill. The endophyte was identified as Cercospora piaropi by ITS and β-tubulin-based phylogenetic analyses, while chemoprofiling of the endophyte by column chromatography and spectroscopy yielded two pure compounds, F.A. and AFA. The compounds demonstrated different antimicrobial profiles, with AFA suppressing the growth of C. albicans at 7.3 µg ml-1 IC50. Further studies revealed that AFA strongly restricted the biofilm production and hyphae formation in C. albicans by down-regulating several biofilm and morphogenesis-related genes. The time-kill assays confirmed the fungicidal activity of AFA against C. albicans, killing 83.6% of the pathogen cells in 24 h at the MIC concentration, and the post-antibiotic effect (PAE) experiments established the suppression of C. albicans growth for extended time periods. The compound acted synergistically with amphotericin B and nystatin and reduced ergosterol biosynthesis by the pathogen, confirmed by ergosterol estimation and comparative expression profiling of selected genes and molecular docking of AFA with C. albicans squalene epoxidase. AFA also suppressed the expression of several other virulence genes of the fungal pathogen. The study determines the anti-C. albicans potential of AFA and its impact on the biology of the pathogen. It also indicates that Cercospora species may yield potential bioactive molecules, especially fulvic acid derivatives. However, it is imperative to conduct in vivo studies to explore this molecule's therapeutic potential further.},
}
@article {pmid35365607,
year = {2022},
author = {Krause, S and Gfrerer, S and von Kügelgen, A and Reuse, C and Dombrowski, N and Villanueva, L and Bunk, B and Spröer, C and Neu, TR and Kuhlicke, U and Schmidt-Hohagen, K and Hiller, K and Bharat, TAM and Rachel, R and Spang, A and Gescher, J},
title = {The importance of biofilm formation for cultivation of a Micrarchaeon and its interactions with its Thermoplasmatales host.},
journal = {Nature communications},
volume = {13},
number = {1},
pages = {1735},
pmid = {35365607},
issn = {2041-1723},
support = {/WT_/Wellcome Trust/United Kingdom ; 202231/Z/16/Z/WT_/Wellcome Trust/United Kingdom ; },
mesh = {Archaea/genetics ; Biofilms ; Genome, Archaeal ; Phylogeny ; *Thermoplasmales/genetics/metabolism ; },
abstract = {Micrarchaeota is a distinctive lineage assigned to the DPANN archaea, which includes poorly characterised microorganisms with reduced genomes that likely depend on interactions with hosts for growth and survival. Here, we report the enrichment of a stable co-culture of a member of the Micrarchaeota (Ca. Micrarchaeum harzensis) together with its Thermoplasmatales host (Ca. Scheffleriplasma hospitalis), as well as the isolation of the latter. We show that symbiont-host interactions depend on biofilm formation as evidenced by growth experiments, comparative transcriptomic analyses and electron microscopy. In addition, genomic, metabolomic, extracellular polymeric substances and lipid content analyses indicate that the Micrarchaeon symbiont relies on the acquisition of metabolites from its host. Our study of the cell biology and physiology of a Micrarchaeon and its host adds to our limited knowledge of archaeal symbioses.},
}
@article {pmid35364199,
year = {2022},
author = {Vinotha, V and Yazhiniprabha, M and Jeyavani, J and Vaseeharan, B},
title = {Synthesis and characterization of cry protein coated zinc oxide nanocomposites and its assessment against bacterial biofilm and mosquito vectors.},
journal = {International journal of biological macromolecules},
volume = {208},
number = {},
pages = {935-947},
doi = {10.1016/j.ijbiomac.2022.03.165},
pmid = {35364199},
issn = {1879-0003},
mesh = {Animals ; Anti-Bacterial Agents/chemistry ; Biofilms ; *Insecticides/chemistry ; *Metal Nanoparticles/chemistry ; Mosquito Vectors ; *Nanocomposites ; Plant Extracts/chemistry ; Plant Leaves/chemistry ; Pseudomonas aeruginosa ; Staphylococcus aureus ; *Zinc Oxide/chemistry/pharmacology ; },
abstract = {Mosquitoes need to be eradicated as they can spread deadly diseases. Cry toxic proteins from Bacillus and zinc oxide nanoparticles also can tremendously control pest and bacterial pathogens. With this reference, the Ac-ZnO NPs was effectively synthesized using Acorus calamus rhizomes extract where after incorporated with bacterial cry toxic protein (Btp) to produce Btp-Ac-ZnO nanocomposites. The XRD and FTIR, disclose the crystalline form with an average size of 17.47 nm and the possible biomolecules of Btp-Ac-ZnO NCs. SEM and TEM make known the well agglomerated and cone shape of Btp-Ac-ZnO NCs. The NCs show concentration-dependent antioxidant activity. Btp-Ac-ZnO NCs drastically arrest the formation of biofilm by the pathogenic bacteria such as E. faecalis, S. aureus, P. aeruginosa, and P. vulgaris at 100 μg/mL. All the above, the Btp-Ac-ZnO NCs exhibits superior larvicidal activity against three mosquito vectors namely Ae. aegypti, An. stephensi and Cx. quinquefasciatus with LC50 values of 43.76, 39.60 and 37.13 μg/mL respectively. Besides, the biological enzymes are significantly reduced in the treated larvae than that of untreated one, which indicates the effect of Btp-Ac-ZnO NCs. Since, the Btp-Ac-ZnO NCs could be utilized against the pathogenic bacteria, and its biofilm structure, and also in the vector control sectors.},
}
@article {pmid35357222,
year = {2022},
author = {Lacasse, M and Valentin, AS and Corvec, S and Bémer, P and Jolivet-Gougeon, A and Plouzeau, C and Tandé, D and Mereghetti, L and Bernard, L and Lartigue, MF and , },
title = {Genotypic Characterization and Biofilm Production of Group B Streptococcus Strains Isolated from Bone and Joint Infections.},
journal = {Microbiology spectrum},
volume = {10},
number = {2},
pages = {e0232921},
pmid = {35357222},
issn = {2165-0497},
support = {//CHU de Tours/Annee recherche/ ; },
mesh = {Adhesins, Bacterial/genetics ; Biofilms ; Female ; Genotype ; Humans ; Multilocus Sequence Typing ; Phylogeny ; *Streptococcal Infections ; *Streptococcus agalactiae/genetics ; },
abstract = {Bone and joint infections (BJI) represent the second cause of invasive Group B Streptococcus (GBS) infections. Biofilm formation plays a major role in BJI. This study's aim was to analyze the genetic features and biofilm production of GBS strains. In six French laboratories, 77 GBS strains isolated from BJI and 57 strains from vaginal human colonization (Hcol) were characterized and compared by Multi-Locus Sequence Typing (MLST). PCR was used to search for the adhesins (bsaB, lmb, scpB, fbsA, fbsB, hvgA, bibA, bca, srr-1, and srr-2) and Pilus Islands (PI) related genes (PI-1, PI-2a, PI-2b). Biofilm production was studied by crystal violet assay. Strains were categorized into three groups, based on Specific Biofilm Formation (SBF) values defined as: weak, moderate, or strong producers. Molecular study revealed three major clonal complexes (CC) in BJI strains: CC1 (42%), CC23 (22%) and CC10 (14%). Several associations between CC and adhesin/pili were identified: CC1 with srr2, PI-1 + 2a; CC10 with srr-1, bca, PI-1 + 2a; CC17 with fbsB, hvgA, srr-2, PI-1+PI-2b; CC19 with bibA, srr-1, PI-1 + 2a; CC23 with fbsB, bibA, srr-1, PI-2a. The biofilm production was significantly different according to CC, adhesins and pili gene detection. CC10, CC23 and strains harboring fbsB produce more biofilm than CC1, PI-1 + 2a (independently). Finally, SBF values were significantly stronger for Hcol strains rather than for BJI strains (76% versus 40%). This study revealed that Hcol strains appeared to produce stronger biofilm than BJI strains, though they belonged to similar CCs and had the same adhesin and pili content. IMPORTANCE Bone and joint infections (BJI) are pathologies that can be life-threatening and result in compromised functional prognosis for patients. Relapses are common and often related to biofilm formation. Group B streptococci (GBS) BJI increased since the last decade. However, few data are available on this subject in the literature. Our study aims to highlight genotype and biofilm production of GBS isolates from BJI. Seventy-seven GBS strains isolated from BJI and 57 from asymptomatic human vaginal colonization were characterized by multilocus sequence typing (MLST), adhesins content, nature of the pili and the ability to form biofilm. Our results revealed that vaginal human colonization strains produced stronger biofilm than BJI strains, d