@article {pmid39044574,
year = {2024},
author = {Wang, Z and Chen, J and You, Z and Liu, X and Zhang, J},
title = {[Advances in mechanisms of biofilm formation and drug resistance of Staphylococcus aureus].},
journal = {Sheng wu gong cheng xue bao = Chinese journal of biotechnology},
volume = {40},
number = {7},
pages = {2038-2051},
doi = {10.13345/j.cjb.230803},
pmid = {39044574},
issn = {1872-2075},
mesh = {*Biofilms/drug effects/growth & development ; *Staphylococcus aureus/drug effects/physiology ; *Anti-Bacterial Agents/pharmacology ; Humans ; Staphylococcal Infections/microbiology ; Drug Resistance, Multiple, Bacterial ; Drug Resistance, Bacterial ; },
abstract = {Staphylococcus aureus is a common pathogenic bacterium. However, due to the abuse of antibiotics, multiple drug-resistant S. aureus (DR S. aureus) has emerged in a large number, which seriously threatens human health. DR S. aureus usually forms biofilms by attaching on contact surfaces and secreting macromolecules including polysaccharides, proteins, and lipids, thus encasing themselves in a self-generated polymeric matrix. A biofilm provides an efficacious barrier that protects bacteria from detrimental environmental factors. Simultaneously, it protects DR S. aureus from the host immune system and attenuates the penetration and killing effects of drugs, serving as a key structure for the development of drug resistance. Therefore, gaining an in-depth understanding of the DR S. aureus biofilm is crucial for treating related infectious diseases. In this paper, we summarize recent research progress in the biofilm formation mechanism, drug resistance mechanism, and measures for inhibition and clearance of DR S. aureus and provide an outlook on the future research directions.},
}

*Biofilms/drug effects/growth & development
*Staphylococcus aureus/drug effects/physiology
*Anti-Bacterial Agents/pharmacology
Humans
Staphylococcal Infections/microbiology
Drug Resistance, Multiple, Bacterial
Drug Resistance, Bacterial

@article {pmid39042175,
year = {2024},
author = {Kirchhoff, L and Arweiler-Harbeck, D and Meyer, M and Buer, J and Lang, S and Steinmann, J and Bertram, R and Deuss, E and Höing, B},
title = {Bacterial biofilm formation on headpieces of Cochlear implants.},
journal = {European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery},
volume = {},
number = {},
pages = {},
pmid = {39042175},
issn = {1434-4726},
abstract = {INTRODUCTION: Bacterial biofilm formation on medical devices, such as Cochlear implants (CI), can lead to chronic infections. Not only the inner parts of the implant but also the externally located headpiece might be associated with prolonged superficial skin eczema resulting in the inability of wearing the headpiece. In this study, the surface of three CI headpieces from different manufacturers were examined for bacterial biofilm formation.

MATERIALS AND METHODS: Two bacterial species associated with implant-related infections were tested: Pseudomonas aeruginosa (ATCC9027) and Staphylococcus aureus (ATCC6538). Biofilms were formed over 24 h in tryptic soy broth at 36 °C. Biofilm formation was detected in form of biomass measurement by crystal violet staining. CI headpiece dummies of three manufacturers were used.

RESULTS: Both tested bacterial species formed biofilms on the examined CI headpiece-surfaces in a species-dependent manner with higher biofilm formation of P. aeruginosa. For both, S. aureus and P. aeruginosa, biofilm formation on the CI components was comparable to a polystyrene control surface. Between the three manufacturers, no significant difference in biofilm formation was found.

DISCUSSION: The tested bacteria displayed biofilm formation on the CI headpieces in a species-specific manner with higher amount of biofilm formed by P. aeruginosa. The biofilm formation was comparable between the manufacturers. In this study, an enhanced biofilm formation on CI headpieces could not be demonstrated. These in vitro tests suggest a minor role of bacterial biofilm on the CI headpiece in skin infections under the CI headpiece.},
}

@article {pmid39040541,
year = {2024},
author = {Pan, Z and Dai, C and Li, W},
title = {Material-based treatment strategies against intraosseous implant biofilm infection.},
journal = {Biochemistry and biophysics reports},
volume = {39},
number = {},
pages = {101764},
pmid = {39040541},
issn = {2405-5808},
abstract = {Implant-associated infections present a significant clinical obstacle for orthopedic practitioners, with bacterial biofilm formation serving as a pivotal factor in the initiation, progression, and management of such infections. Conventional approaches have proven inadequate in fully eradicating biofilm-related infections. Consequently, novel material-based therapeutic strategies have been developed, encompassing the utilization of antimicrobial agents, delivery vehicles, and synergistic antibacterial systems. In this review, we provide a succinct overview of recent advancements in anti-biofilm strategies, with the aim of offering insights that may aid in the treatment of intraosseous implant infections.},
}

@article {pmid39040382,
year = {2024},
author = {Chandraraj, SS and Suyambulingam, I and Edayadulla, N and Divakaran, D and Singh, MK and Sanjay, MR and Siengchin, S},
title = {Characterization of Calotropis gigantiea plant leaves biomass-based bioplasticizers for biofilm applications.},
journal = {Heliyon},
volume = {10},
number = {13},
pages = {e33641},
pmid = {39040382},
issn = {2405-8440},
abstract = {The present surge in environmental consciousness has pushed for the use of biodegradable plasticizers, which are sustainable and abundant in plant resources. As a result of their biocompatibility and biodegradability, Calotropis gigantiea leaf plasticizers (CLP) serve as viable alternatives to chemical plasticizers. First time, the natural plasticizers from the Calotropis leaves were extracted for this study using a suitable chemical approach that was also environmentally friendly. The XRD results showed a reduced crystallinity index of 20.2 % and a crystalline size of 5.3 nm, respectively. TGA study revealed that the CLP has good thermal stability (244 °C). Through FT-IR study, the existence of organic compounds in CLP can be investigated by key functional groups such as alcohol, amine, amide, hydrocarbon, alkene, aromatic, etc. Further the presence of alcoholic, amino, and carboxyl constituents was confirmed by UV investigation. SEM, EDAX analysis, and AFM are used to examine the surface morphology of the isolated plasticizer. SEM pictures reveal rough surfaces on the CLP surface pores, which makes them suitable for plasticizing new bioplastics with improved mechanical properties. Poly (butylene adipate-co-terephthalate) (PBAT), a biodegradable polymer matrix, was used to investigate the plasticization impact after the macromolecules were characterised. The biofilm PBAT/CLP had a thickness of 0.8 mm. In addition, the reinforcement interface was examined using scanning electron microscopy. When CLP is loaded differently in PBAT, the tensile strength and young modulus change from 15.30 to 24.60 MPa and from 137 to 168 MPa, respectively. CLP-reinforced films demonstrated better surface compatibility and enhanced flexibility at a loading of 2 % when compared to pure PBAT films. Considering several documented characteristics, CLP may prove to be an excellent plasticizer for resolving environmental issues in the future.},
}

@article {pmid39039267,
year = {2024},
author = {Silva, AR and Melo, LF and Keevil, CW and Pereira, A},
title = {Legionella colonization and 3D spatial location within a Pseudomonas biofilm.},
journal = {Scientific reports},
volume = {14},
number = {1},
pages = {16781},
pmid = {39039267},
issn = {2045-2322},
support = {LEPABE//Fundação para a Ciência e a Tecnologia/ ; },
mesh = {*Biofilms/growth & development ; *Legionella pneumophila/physiology ; *Pseudomonas fluorescens/physiology ; Legionella/physiology ; Microscopy, Confocal ; Tomography, Optical Coherence ; },
abstract = {Biofilms are known to be critical for Legionella settlement in engineered water systems and are often associated with Legionnaire's Disease events. One of the key features of biofilms is their heterogeneous three-dimensional structure which supports the establishment of microbial interactions and confers protection to microorganisms. This work addresses the impact of Legionella pneumophila colonization of a Pseudomonas fluorescens biofilm, as information about the interactions between Legionella and biofilm structures is scarce. It combines a set of meso- and microscale biofilm analyses (Optical Coherence Tomography, Episcopic Differential Interference Contrast coupled with Epifluorescence Microscopy and Confocal Laser Scanning Microscopy) with PNA-FISH labelled L. pneumophila to tackle the following questions: (a) does the biofilm structure change upon L. pneumophila biofilm colonization?; (b) what happens to L. pneumophila within the biofilm over time and (c) where is L. pneumophila preferentially located within the biofilm? Results showed that P. fluorescens structure did not significantly change upon L. pneumophila colonization, indicating the competitive advantage of the first colonizer. Imaging of PNA-labelled L. pneumophila showed that compared to standard culture recovery it colonized to a greater extent the 3-day-old P. fluorescens biofilms, presumably entering in VBNC state by the end of the experiment. L. pneumophila was mostly located in the bottom regions of the biofilm, which is consistent with the physiological requirements of both bacteria and confers enhanced Legionella protection against external aggressions. The present study provides an expedited methodological approach to address specific systematic laboratory studies concerning the interactions between L. pneumophila and biofilm structure that can provide, in the future, insights for public health Legionella management of water systems.},
}

*Biofilms/growth & development
*Legionella pneumophila/physiology
*Pseudomonas fluorescens/physiology
Legionella/physiology
Microscopy, Confocal
Tomography, Optical Coherence

@article {pmid39038400,
year = {2024},
author = {Gao, SC and Fan, XX and Zhang, Z and Li, RT and Zhang, Y and Gao, TP and Liu, Y},
title = {A dual-function mixed-culture biofilm for sulfadiazine removal and electricity production using bio-electrochemical system.},
journal = {Biosensors & bioelectronics},
volume = {263},
number = {},
pages = {116552},
doi = {10.1016/j.bios.2024.116552},
pmid = {39038400},
issn = {1873-4235},
abstract = {Sulfadiazine (SDZ) is frequently detected in environmental samples, arousing much concern due to its toxicity and hard degradation. This study investigated the electricity generation capabilities, SDZ removal and microbial communities of a highly efficient mixed-culture system using repeated transfer enrichments in a bio-electrochemical system. The mixed-culture biofilm (S160-T2) produced a remarkable current density of 954.12 ± 15.08 μA cm[-2] with 160 mg/L SDZ, which was 32.9 and 1.8 times higher than that of Geobacter sulfurreducens PCA with 40 mg/L SDZ and without additional SDZ, respectively. Especially, the impressive SDZ removal rate of 98.76 ± 0.79% was achieved within 96 h using the further acclimatized mixed-culture. The removal efficiency of this mixed-culture for SDZ through the bio-electrochemical system was 1.1 times higher than that using simple anaerobic biodegradation. Furthermore, the current density and removal efficiency in this system gradually decreased with increasing SDZ concentrations from 0 to 800 mg/L. In addition, community diversity data demonstrated that the dominant genera, Geobacter and Escherichia-Shigella, were enriched in mixed-culture biofilm, which might be responsible for the current production and SDZ removal. This work confirmed the important roles of acclimatized microbial consortia and co-substrates in the simultaneous removal of SDZ and electricity generation in an electrochemical system.},
}

@article {pmid39037897,
year = {2024},
author = {Zermeño-Pérez, D and Chouirfa, H and Rodriguez, BJ and Dürig, T and Duffy, P and Cróinín, TÓ},
title = {Bioresorbable Polyester Coatings with Antifouling and Antimicrobial Properties for Prevention of Biofilm Formation in Early Stage Infections on Ti6Al4V Hard-Tissue Implants.},
journal = {ACS applied bio materials},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsabm.4c00832},
pmid = {39037897},
issn = {2576-6422},
abstract = {Implants made from titanium are used as prostheses because of their biocompatibility and their mechanical properties close to those of human bone. However, the risk of bacterial infection is always a major concern during surgery, and the development of biofilm can make these infections difficult to treat. A promising strategy to mitigate against bacterial infections is the use of antifouling and antimicrobial coatings, where bioresorbable polymers can play an important role due to their controlled degradability and sustained drug release, as well as excellent biocompatibility. In the present study, poly(d,l-lactide) (PDLLA) and poly[d,l-lactide-co-methyl ether poly(ethylene glycol)] (PDLLA-PEG) were studied, varying the PEG content (20-40% w/w) to analyze the effectiveness of PEG as an antifouling molecule. In addition, silver sulfadiazine (AgSD) was used as an additional antimicrobial agent with a concentration ≤5% w/w and incorporated into the PEGylated polymers to create a polymer with both antifouling and antimicrobial properties. Polymers synthesized were applied using spin coating to obtain homogeneous coatings to protect samples made from titanium/aluminum/vanadium (Ti6Al4V). The polymer coatings had a smoothing effect in comparison to that of the uncoated material, decreasing the contact area available for bacterial colonization. It was also noted that PEG addition into the polymeric chain developed amphiphilic materials with a decrease in contact angle from the most hydrophobic (Ti6Al4V) to the most hydrophilic PDLLA-PEG (60/40), highlighting the increase in water uptake contributing to the hydration layer formation, which confers the antifouling effect on the coating. This study demonstrated that the addition of PEG above 20% w/w and AgSD above 1% w/v into the formulation was able to decrease bacterial adherence against clinically relevant biofilm former strains Staphylococcus aureus and Pseudomonas aeruginosa.},
}

@article {pmid39037809,
year = {2024},
author = {Aydın, E and Kocaaga, M and Temel, A},
title = {Association of antibiotic resistance and biofilm formation in Escherichia coli ST131/O25b.},
journal = {Acta microbiologica et immunologica Hungarica},
volume = {},
number = {},
pages = {},
doi = {10.1556/030.2024.02275},
pmid = {39037809},
issn = {1588-2640},
abstract = {Urinary tract infections are becoming difficult to treat every year due to antibiotic resistance. Uropathogenic Escherichia coli (UPEC) isolates pose a threat with a combined expression of multidrug-resistance and biofilm formation. ST131 clone is a high-risk pandemic clone due to its strong association with antimicrobial resistance, which has been reported frequently in recent years. This study aims to define risk factors, clinical outcomes, and bacterial genetics associated with ST131/O25b UPEC. In this study, antibiotic susceptibility and species-level identification of 61 clinical E. coli strains were determined by automated systems. Detection of extended-spectrum beta-lactamases was assessed by double-disk synergy test. Biofilm formation was quantified by spectrophotometric method. Virulence genes (iutA, sfa cnf-1, iroN, afa, papA, fimA), antibiotic resistance genes (blaCTX-M, blaTEM, blaSHV, blaOXA, qnrA, qnrB, qnrS, ant(2')-Ia, ant(3)-Ia, aac(3)-IIa, mcr-1, mcr-2, mcr-3, mcr-4) were investigated by PCR. The following beta-lactamase genes were identified, blaTEM (n = 53, 86.8%), blaCTX-M (n = 59, 96.7%), blaSHV (n = 47, 77.0%), and blaOXA-1 (n = 27, 44.2%). Our data revealed that 93.4% of (57/61) E. coli isolates were biofilm-producers. O25pabBspe and trpA2 were investigated for the presence of ST131/O25b clone. Among multidrug resistant isolates, co-existence of O25pabBspe and trpA2 was detected in 29 isolates (47.5%). The fimH30 and H30Rx subclones were detected in four isolates that are strong biofilm-producers. These results suggest that clinical E. coli strains may become reservoirs of virulence and antibiotic resistance genes. This study demonstrates a significant difference in biofilm formation between E. coli ST131 and non-ST131 isolates. Moreover, 86.21% (n = 25) of ST131 isolates produced strong to moderate biofilms, while only 43.75% (n = 14) of non-ST131 isolates showed the ability to form strong biofilms. Presence of iutA and fimA genes in the majority of ST131 strains showed an important role in biofilm formation. These findings suggest application of iutA and fimA gene suppressors in treatment of infections caused by biofilm-producing drug-resistant ST131 strains.},
}

@article {pmid39037271,
year = {2024},
author = {Mookherjee, A and Mitra, M and Sason, G and Jose, PA and Martinenko, M and Pietrokovski, S and Jurkevitch, E},
title = {Flagellar stator genes control a trophic shift from obligate to facultative predation and biofilm formation in a bacterial predator.},
journal = {mBio},
volume = {},
number = {},
pages = {e0071524},
doi = {10.1128/mbio.00715-24},
pmid = {39037271},
issn = {2150-7511},
abstract = {UNLABELLED: The bacterial predator Bdellovibrio bacteriovorus is considered to be obligatorily prey (host)-dependent (H-D), and thus unable to form biofilms. However, spontaneous host-independent (H-I) variants grow axenically and can form robust biofilms. A screen of 350 H-I mutants revealed that single mutations in stator genes fliL or motA were sufficient to generate flagellar motility-defective H-I strains able to adhere to surfaces but unable to develop biofilms. The variants showed large transcriptional shifts in genes related to flagella, prey-invasion, and cyclic-di-GMP (CdG), as well as large changes in CdG cellular concentration relative to the H-D parent. The introduction of the parental fliL allele resulted in a full reversion to the H-D phenotype, but we propose that specific interactions between stator proteins prevented functional complementation by fliL paralogs. In contrast, specific mutations in a pilus-associated protein (Bd0108) mutant background were necessary for biofilm formation, including secretion of extracellular DNA (eDNA), proteins, and polysaccharides matrix components. Remarkably, fliL disruption strongly reduced biofilm development. All H-I variants grew similarly without prey, showed a strain-specific reduction in predatory ability in prey suspensions, but maintained similar high efficiency in prey biofilms. Population-wide allele sequencing suggested additional routes to host independence. Thus, stator and invasion pole-dependent signaling control the H-D and the H-I biofilm-forming phenotypes, with single mutations overriding prey requirements, and enabling shifts from obligate to facultative predation, with potential consequences on community dynamics. Our findings on the facility and variety of changes leading to facultative predation also challenge the concept of Bdellovibrio and like organisms being obligate predators.

IMPORTANCE: The ability of bacteria to form biofilms is a central research theme in biology, medicine, and the environment. We show that cultures of the obligate (host-dependent) "solitary" predatory bacterium Bdellovibrio bacteriovorus, which cannot replicate without prey, can use various genetic routes to spontaneously yield host-independent (H-I) variants that grow axenically (as a single species, in the absence of prey) and exhibit various surface attachment phenotypes, including biofilm formation. These routes include single mutations in flagellar stator genes that affect biofilm formation, provoke motor instability and large motility defects, and disrupt cyclic-di-GMP intracellular signaling. H-I strains also exhibit reduced predatory efficiency in suspension but high efficiency in prey biofilms. These changes override the requirements for prey, enabling a shift from obligate to facultative predation, with potential consequences on community dynamics.},
}

@article {pmid39035353,
year = {2024},
author = {Zuberi, A and Ahmad, N and Ahmad, H and Saeed, M and Ahmad, I},
title = {Beyond antibiotics: CRISPR/Cas9 triumph over biofilm-associated antibiotic resistance infections.},
journal = {Frontiers in cellular and infection microbiology},
volume = {14},
number = {},
pages = {1408569},
pmid = {39035353},
issn = {2235-2988},
mesh = {*Biofilms/drug effects/growth & development ; *CRISPR-Cas Systems ; *Anti-Bacterial Agents/pharmacology ; Humans ; Bacteria/drug effects/genetics ; Drug Resistance, Bacterial/genetics ; Bacterial Infections/microbiology/drug therapy ; Gene Editing ; },
abstract = {A complex structure known as a biofilm is formed when a variety of bacterial colonies or a single type of cell in a group sticks to a surface. The extracellular polymeric compounds that encase these cells, often consisting of proteins, eDNA, and polysaccharides, exhibit strong antibiotic resistance. Concerns about biofilm in the pharmaceutical industry, public health, and medical fields have sparked a lot of interest, as antibiotic resistance is a unique capacity exhibited by these biofilm-producing bacteria, which increases morbidity and death. Biofilm formation is a complicated process that is controlled by several variables. Insights into the processes to target for the therapy have been gained from multiple attempts to dissect the biofilm formation process. Targeting pathogens within a biofilm is profitable because the bacterial pathogens become considerably more resistant to drugs in the biofilm state. Although biofilm-mediated infections can be lessened using the currently available medications, there has been a lot of focus on the development of new approaches, such as bioinformatics tools, for both treating and preventing the production of biofilms. Technologies such as transcriptomics, metabolomics, nanotherapeutics and proteomics are also used to develop novel anti-biofilm agents. These techniques help to identify small compounds that can be used to inhibit important biofilm regulators. The field of appropriate control strategies to avoid biofilm formation is expanding quickly because of this spurred study. As a result, the current article addresses our current knowledge of how biofilms form, the mechanisms by which bacteria in biofilms resist antibiotics, and cutting-edge treatment approaches for infections caused by biofilms. Furthermore, we have showcased current ongoing research utilizing the CRISPR/Cas9 gene editing system to combat bacterial biofilm infections, particularly those brought on by lethal drug-resistant pathogens, concluded the article with a novel hypothesis and aspirations, and acknowledged certain limitations.},
}

*Biofilms/drug effects/growth & development
*CRISPR-Cas Systems
*Anti-Bacterial Agents/pharmacology
Humans
Bacteria/drug effects/genetics
Drug Resistance, Bacterial/genetics
Bacterial Infections/microbiology/drug therapy
Gene Editing

@article {pmid39035281,
year = {2024},
author = {Wongsuwanlert, M and Teanpaisan, R and Ruangsri, P and Kaewdech, A and Sunpaweravong, S and Pahumunto, N},
title = {Effect of mouthwash containing poly l-Lysine and glycerol monolaurate on oral Helicobacter pylori relating to biofilm eradication, anti-adhesion, and pro-inflammatory cytokine suppression.},
journal = {Journal of dental sciences},
volume = {19},
number = {3},
pages = {1748-1757},
pmid = {39035281},
issn = {2213-8862},
abstract = {BACKGROUND/PURPOSE: Helicobacter pylori has been found to be related to periodontitis, and the oral cavity has been considered a reservoir for H. pylori gastritis infection. Thus, this study evaluated the effect of mouthwash containing poly l-Lysine and glycerol monolaurate on inhibiting H. pylori growth, biofilm formation, cell cytotoxicity, adhesion ability, cagA mRNA expression, and pro-inflammatory cytokines stimulated by H. pylori.

MATERIALS AND METHODS: Nineteen H. pylori strains were isolated from the oral cavity. The effectiveness of mouthwash containing poly l-Lysine and glycerol monolaurate was examined for its ability to inhibit H. pylori growth and biofilm formation and was tested for cell viability in oral epithelial cells (H357), gastric adenocarcinoma cells (AGS), and periodontal ligament cells (PDL). Additionally, the mouthwash was tested for reducing cagA mRNA expression, adhesion ability to H357 and AGS cells, and pro-inflammatory cytokines stimulated with H. pylori in AGS and PDL cells.

RESULTS: The mouthwash containing poly l-Lysine and glycerol monolaurate could eradicate the biofilm by 14.9-19.9% after incubation at 5 min, and cell viability revealed 77.2, 79.8, and 100.0% for AGS, H357, and PDL cells, respectively. Moreover, the mouthwash containing poly l-Lysine and glycerol monolaurate could down-regulate cagA mRNA expression, reduce adhesion of H. pylori by approximately 9.5-47.8% for H357 cells and 24.5-62.9% for AGS cells, and decrease pro-inflammatory cytokines, especially interleukin-8, stimulated with H. pylori.

CONCLUSION: Mouthwash containing poly l-Lysine and glycerol monolaurate could inhibit H. pylori growth and reduce their virulence expression. The mouthwash also revealed low cytotoxicity to oral and gastric cells.},
}

@article {pmid39034023,
year = {2024},
author = {Liu, Y and Dai, A and Xia, L and Zhou, Y and Ren, T and Huang, Y and Zhou, Y},
title = {Deciphering the Roles of Nitrogen Source in Sharping Synchronous Metabolic Pathways of Linear Alkylbenzene Sulfonate and Nitrogen in a Membrane Biofilm for Treating Greywater.},
journal = {Environmental research},
volume = {},
number = {},
pages = {119650},
doi = {10.1016/j.envres.2024.119650},
pmid = {39034023},
issn = {1096-0953},
abstract = {Nitrogen (N) source is an important factor affecting biological wastewater treatment. Although the oxygen-based membrane biofilm showed excellent greywater treatment performance, how N source impacts the synchronous removal of organics and N is still unclear. In this work, how N species (urea, nitrate and ammonia) affect synchronous metabolic pathways of organics and N were evaluated during greywater treatment in the membrane biofilm. Urea and ammonia achieved efficient chemical oxygen demand (> 97.5%) and linear alkylbenzene sulfonate (LAS, > 98.5%) removal, but nitrate enabled the maximum total N removal (80.8 ± 2.6%). The nitrate-added system had poor LAS removal ratio and high residual LAS, promoting the accumulation of effluent protein-like organics and fulvic acid matter. N source significantly induced bacterial community succession, and the increasing of corresponded functional flora can promote the tra\ormation and utilization of microbial-mediated N. The nitrate system was more conducive to the accumulation of denitrification related microorganisms and enzymes, enabling the efficient N removal. Combining with high amount of ammonia monooxygenase that contributing to LAS and N co-metabolism, LAS mineralization related microbes and functional enzymes were generously accumulated in the urea and ammonia systems, which achieved the high efficiency of organics and LAS removal.},
}

@article {pmid39033146,
year = {2024},
author = {Varin-Simon, J and Colin, M and Velard, F and Tang-Fichaux, M and Ohl, X and Mongaret, C and Gangloff, SC and Reffuveille, F},
title = {Cutibacterium acnes biofilm formation is influenced by bone microenvironment, implant surfaces and bacterial internalization.},
journal = {BMC microbiology},
volume = {24},
number = {1},
pages = {270},
pmid = {39033146},
issn = {1471-2180},
mesh = {*Biofilms/growth & development ; *Titanium ; *Prosthesis-Related Infections/microbiology ; Humans ; Bacterial Adhesion ; Propionibacteriaceae/physiology/genetics/drug effects ; Prostheses and Implants/microbiology ; Bone and Bones/microbiology ; Plastics ; Alloys ; Surface Properties ; },
abstract = {BACKGROUND: The bacterial persistence, responsible for therapeutic failures, can arise from the biofilm formation, which possesses a high tolerance to antibiotics. This threat often occurs when a bone and joint infection is diagnosed after a prosthesis implantation. Understanding the biofilm mechanism is pivotal to enhance prosthesis joint infection (PJI) treatment and prevention. However, little is known on the characteristics of Cutibacterium acnes biofilm formation, whereas this species is frequently involved in prosthesis infections.

METHODS: In this study, we compared the biofilm formation of C. acnes PJI-related strains and non-PJI-related strains on plastic support and textured titanium alloy by (i) counting adherent and viable bacteria, (ii) confocal scanning electronic microscopy observations after biofilm matrix labeling and (iii) RT-qPCR experiments.

RESULTS: We highlighted material- and strain-dependent modifications of C. acnes biofilm. Non-PJI-related strains formed aggregates on both types of support but with different matrix compositions. While the proportion of polysaccharides signal was higher on plastic, the proportions of polysaccharides and proteins signals were more similar on titanium. The changes in biofilm composition for PJI-related strains was less noticeable. For all tested strains, biofilm formation-related genes were more expressed in biofilm formed on plastic that one formed on titanium. Moreover, the impact of C. acnes internalization in osteoblasts prior to biofilm development was also investigated. After internalization, one of the non-PJI-related strains biofilm characteristics were affected: (i) a lower quantity of adhered bacteria (80.3-fold decrease), (ii) an increase of polysaccharides signal in biofilm and (iii) an activation of biofilm gene expressions on textured titanium disk.

CONCLUSION: Taken together, these results evidenced the versatility of C. acnes biofilm, depending on the support used, the bone environment and the strain.},
}

*Biofilms/growth & development
*Titanium
*Prosthesis-Related Infections/microbiology
Humans
Bacterial Adhesion
Propionibacteriaceae/physiology/genetics/drug effects
Prostheses and Implants/microbiology
Bone and Bones/microbiology
Plastics
Alloys
Surface Properties

@article {pmid39033094,
year = {2024},
author = {Xu, KZ and You, C and Wang, YJ and Dar, OI and Yin, LJ and Xiang, SL and Jia, AQ},
title = {Repurposing promethazine hydrochloride to inhibit biofilm formation against Burkholderia thailandensis.},
journal = {Medical microbiology and immunology},
volume = {213},
number = {1},
pages = {16},
pmid = {39033094},
issn = {1432-1831},
support = {Qhyb2022-46//Innovative Research Projects for Postgraduates in Hainan Province/ ; Qhyb2021-38//Innovative Research Projects for Postgraduates in Hainan Province/ ; 82160664//National Natural Science Foundation of China/ ; 221CXTD434//Natural Science Foundation of Hainan Province/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Burkholderia/drug effects/physiology/genetics ; *Promethazine/pharmacology ; *Drug Repositioning ; Molecular Docking Simulation ; Anti-Bacterial Agents/pharmacology ; Lipase/metabolism/genetics ; Gene Expression Regulation, Bacterial/drug effects ; Bacterial Proteins/genetics/metabolism ; Humans ; Quorum Sensing/drug effects ; },
abstract = {Melioidosis is a severe infectious disease caused by Burkholderia pseudomallei, an intracellular pathogen with a high mortality rate and significant antibiotic resistance. The high mortality rate and resistance to antibiotics have drawn considerable attention from researchers studying melioidosis. This study evaluated the effects of various concentrations (75, 50, and 25 µg/mL) of promethazine hydrochloride (PTZ), a potent antihistamine, on biofilm formation and lipase activity after 24 h of exposure to B. thailandensis E264. A concentration-dependent decrease in both biofilm biomass and lipase activity was observed. RT-PCR analysis revealed that PTZ treatment not only made the biofilm structure loose but also reduced the expression of btaR1, btaR2, btaR3, and scmR. Single gene knockouts of quorum sensing (QS) receptor proteins (∆btaR1, ∆btaR2, and ∆btaR3) were successfully constructed. Deletion of btaR1 affected biofilm formation in B. thailandensis, while deletion of btaR2 and btaR3 led to reduced lipase activity. Molecular docking and biological performance results demonstrated that PTZ inhibits biofilm formation and lipase activity by suppressing the expression of QS-regulated genes. This study found that repositioning PTZ reduced biofilm formation in B. thailandensis E264, suggesting a potential new approach for combating melioidosis.},
}

*Biofilms/drug effects/growth & development
*Burkholderia/drug effects/physiology/genetics
*Promethazine/pharmacology
*Drug Repositioning
Molecular Docking Simulation
Anti-Bacterial Agents/pharmacology
Lipase/metabolism/genetics
Gene Expression Regulation, Bacterial/drug effects
Bacterial Proteins/genetics/metabolism
Humans
Quorum Sensing/drug effects

@article {pmid39033083,
year = {2024},
author = {Junior, HLA and Assis, TM and Faria, EC and Costa, LRK and Ibaldo, BM},
title = {Piedraia hortae: biofilm formation and its importance in the pathogenesis of Piedra nigra (black piedra).},
journal = {Anais brasileiros de dermatologia},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.abd.2023.12.005},
pmid = {39033083},
issn = {1806-4841},
abstract = {BACKGROUND: Little is known about the ultrastructure of Piedraia hortae.

OBJECTIVE: To examine a P. hortae colony with scanning electron microscopy and investigate possible contributions to its pathogenesis.

RESULTS: On low magnifications, two distinct aspects of the colony are identified, a compact area and a filamentous area. Analysis of the filamentous area demonstrates hyphae adhered by a thin reticular substance. A recurring finding is the adhesion between the fungal filaments in parallel. On high magnifications, the micro fibrillar substance adhering the hyphae to each other becomes very evident. Examination of the compact area shows the hyphae embedded in the reticular matrix forming a biofilm and the colony well adhered. On high magnification, it can be observed that the hyphae are within this fibrillar matrix, which has the same appearance as the filamentous substance that adheres the hyphae to each other.

STUDY LIMITATIONS: Only one strain was examined.

CONCLUSIONS: The formation of biofilm with fungal structures and reticulated extracellular substance is important in the pathogenesis of Piedra nigra.},
}

@article {pmid39031267,
year = {2024},
author = {Allami, M and Mohammed, EJ and Alnaji, Z and A Jassim, S},
title = {Antibiotic resistance and its correlation with biofilm formation and virulence genes in Klebsiella pneumoniae isolated from wounds.},
journal = {Journal of applied genetics},
volume = {},
number = {},
pages = {},
pmid = {39031267},
issn = {2190-3883},
abstract = {Klebsiella pneumoniae is the most important species of the Klebsiella genus and often causes hospital infections. These bacteria have a high resistance to most of the available drugs, which has caused concern all over the world. In this study, we investigated the antibiotic resistance profile and the ability to produce extended-spectrum beta-lactamase (ESBL) among K. pneumoniae isolates, and then we investigated the relationship between these two factors with biofilm formation and the prevalence of different virulence genes. In this study, 130 isolates of K. pneumoniae isolated from wounds were investigated. The antibiotic resistance of the isolates was evaluated by the disk diffusion method. The microtiter plate method was used to measure biofilm formation. The prevalence of virulence genes was detected by multiplex PCR. Among the examined isolates, 85.3% showed multidrug resistance. 87.6% of the isolates were ESBL-positive. Imipenem, meropenem, and fosfomycin were the most effective drugs. The ability of the isolates to produce biofilm was strong (80%), moderate (12.3%), and weak (7.6%), respectively. fimH, mrKD, entB, and tolC virulence genes were observed in all isolates. High prevalence of antibiotic resistance (especially multidrug resistance), high prevalence of ESBL-producing isolates, the ability of all isolates to biofilm formation, and the presence of fimH, mrKD, entB, and tolC virulence genes in all isolates show the importance of these factors in the pathogenesis of K. pneumoniae isolates in Iraq.},
}

@article {pmid39030869,
year = {2024},
author = {Hou, Z and Ren, X and Sun, Z and An, R and Huang, M and Gao, C and Yin, M and Liu, G and He, D and Du, H and Tang, R},
title = {Trash into Treasure: Nano-coating of Catheter Utilizes Urine to Deprive H2S Against Persister and Rip Biofilm Matrix.},
journal = {Advanced healthcare materials},
volume = {},
number = {},
pages = {e2401067},
doi = {10.1002/adhm.202401067},
pmid = {39030869},
issn = {2192-2659},
support = {82101011,82260477//National Natural Science Foundation of China/ ; lzujbky-2022-ey19//Fundamental Research Funds for the Central Universities/ ; 20YF8WA084,20YF8FA073//Natural Science Foundation of Gansu Province of China/ ; 20JR10FA670//Scientific and Technological Foundation of Gansu Province/ ; GXH20220530-16//Gansu Association for Science and Technology/ ; 20JR10RA653-ZDKF20210301//open fund of Key Laboratory of Dental Maxillofacial Reconstruction and Biological Intelligence Manufacturing, Gansu Province/ ; lzuyxcx-2022-182//Medical Innovation and Development Project of Lanzhou University/ ; lzukqky-2021-q01,lzukqky-2021-q07,lzukqky-2022-q03//Hospital of Stomatology Lanzhou University Scientific Research Project/ ; 2024B-003//Education Technology Innovation Project of Gansu Province in 2024/ ; PKUSS20200103//Youth Research Fund of Peking University School and Hospital of Stomatology/ ; },
abstract = {Bacteria-derived hydrogen sulfide (H2S) often contributes to the emergence of antibiotic-recalcitrant bacteria, especially persister (a sub-population of dormant bacteria), thus causing the treatment failure of Catheter-associated urinary tract infection (CAUTI). Here, an H2S harvester nanosystem to prevent the generation of persister bacteria and disrupt the dense biofilm matrix by the self-adaptive ability of shape-morphing is prepared. The nanosystem possesses a core-shell structure that is composed of liquid metal nanoparticle (LM NP), AgNPs, and immobilized urease. The nanosystem decomposes urea contained in urine to generate ammonia for eliminating bacteria-derived H2S. Depending on the oxidative layer of liquid metal, the nanosystem also constitutes a long-lasting reservoir for temporarily storing bacteria-derived H2S, when urease transiently overloads or in the absence of urine in a catheter. Depriving H2S can prevent the emergence of persistent bacteria, enhancing the bacteria-killing efficiency of Ga[3+] and Ag[+] ions. Even when the biofilm has formed, the urine flow provides heat to trigger shape morphing of the LM NP, tearing the biofilm matrix. Collectively, this strategy can turn trash (urea) into treasure (H2S scavengers and biofilm rippers), and provides a new direction for the antibacterial materials application in the medical field.},
}

@article {pmid39029506,
year = {2024},
author = {Montoya-Hinojosa, EI and Villarreal-Treviño, L and Bocanegra-Ibarias, P and Camacho-Ortiz, A and Flores-Treviño, S},
title = {Drug Resistance in Biofilm and Planktonic Cells of Achromobacter spp., Burkholderia spp., and Stenotrophomonas maltophilia Clinical Isolates.},
journal = {Microbial drug resistance (Larchmont, N.Y.)},
volume = {},
number = {},
pages = {},
doi = {10.1089/mdr.2023.0301},
pmid = {39029506},
issn = {1931-8448},
abstract = {Background: Biofilm production in nonfermenting Gram-negative bacteria influences drug resistance. The aim of this work was to evaluate the effect of different antibiotics on biofilm eradication of clinical isolates of Achromobacter, Burkholderia, and Stenotrophomonas maltophilia. Methods: Clinical isolates were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry in a third-level hospital in Monterrey, Mexico. Crystal violet staining was used to determine biofilm production. Drug susceptibility testing was determined by broth microdilution in planktonic cells and biofilm cells. Results: Resistance in planktonic cells was moderate to trimethoprim-sulfamethoxazole, and low to chloramphenicol, minocycline, levofloxacin (S. maltophilia and Burkholderia), ceftazidime, and meropenem (Burkholderia and Achromobacter). Biofilm eradication required higher drug concentrations of ceftazidime, chloramphenicol, levofloxacin, and trimethoprim-sulfamethoxazole than planktonic cells (p < 0.05). Levofloxacin showed biofilm eradication activity in S. maltophilia, minocycline and meropenem in Burkholderia, and meropenem in Achromobacter. Conclusions: Drug resistance increased due to biofilm production for some antibiotics, particularly ceftazidime and trimethoprim-sulfamethoxazole for all three pathogens, chloramphenicol for S. maltophilia and Burkholderia, and levofloxacin for Burkholderia. Some antibiotics could be used for the treatment of biofilm-associated infections in our population, such as levofloxacin for S. maltophilia, minocycline and meropenem for Burkholderia, and meropenem for Achromobacter.},
}

@article {pmid39028551,
year = {2024},
author = {Malik, A and Oludiran, A and Poudel, A and Alvarez, OB and Woodward, C and Purcell, EB},
title = {RelQ-mediated alarmone signalling regulates growth, stress-induced biofilm formation and spore accumulation in Clostridioides difficile.},
journal = {Microbiology (Reading, England)},
volume = {170},
number = {7},
pages = {},
doi = {10.1099/mic.0.001479},
pmid = {39028551},
issn = {1465-2080},
mesh = {*Biofilms/growth & development ; *Clostridioides difficile/genetics/metabolism/physiology/growth & development ; *Spores, Bacterial/growth & development/metabolism/genetics ; *Bacterial Proteins/genetics/metabolism ; *Gene Expression Regulation, Bacterial ; *Signal Transduction ; *Stress, Physiological ; Anti-Bacterial Agents/pharmacology ; Ligases/genetics/metabolism ; Gene Deletion ; Oxidative Stress ; },
abstract = {The bacterial stringent response (SR) is a conserved transcriptional reprogramming pathway mediated by the nucleotide signalling alarmones, (pp)pGpp. The SR has been implicated in antibiotic survival in Clostridioides difficile, a biofilm- and spore-forming pathogen that causes resilient, highly recurrent C. difficile infections. The role of the SR in other processes and the effectors by which it regulates C. difficile physiology are unknown. C. difficile RelQ is a clostridial alarmone synthetase. Deletion of relQ dysregulates C. difficile growth in unstressed conditions, affects susceptibility to antibiotic and oxidative stressors and drastically reduces biofilm formation. While wild-type C. difficile displays increased biofilm formation in the presence of sublethal stress, the ΔrelQ strain cannot upregulate biofilm production in response to stress. Deletion of relQ slows spore accumulation in planktonic cultures but accelerates it in biofilms. This work establishes biofilm formation and spore accumulation as alarmone-mediated processes in C. difficile and reveals the importance of RelQ in stress-induced biofilm regulation.},
}

*Biofilms/growth & development
*Clostridioides difficile/genetics/metabolism/physiology/growth & development
*Spores, Bacterial/growth & development/metabolism/genetics
*Bacterial Proteins/genetics/metabolism
*Gene Expression Regulation, Bacterial
*Signal Transduction
*Stress, Physiological
Anti-Bacterial Agents/pharmacology
Ligases/genetics/metabolism
Gene Deletion
Oxidative Stress

@article {pmid39027105,
year = {2024},
author = {Wang, L and Liu, P and Wu, Y and Pei, H and Cao, X},
title = {Inhibitory effect of Lonicera japonica flos on Streptococcus mutans biofilm and mechanism exploration through metabolomic and transcriptomic analyses.},
journal = {Frontiers in microbiology},
volume = {15},
number = {},
pages = {1435503},
pmid = {39027105},
issn = {1664-302X},
abstract = {INTRODUCTION: Streptococcus mutans was the primary pathogenic organism responsible for dental caries. Lonicera japonica flos (LJF) is a traditional herb in Asia and Europe and consumed as a tea beverage for thousands of years.

METHODS: The inhibitory effect and mechanism of LJF on biofilm formation by S. mutans was investigated. The active extracts of LJF were validated for their inhibitory activity by examining changes in surface properties such as adherence, hydrophobicity, auto-aggregation abilities, and exopolysaccharides (EPS) production, including water-soluble glucan and water-insoluble glucan.

RESULTS AND DISCUSSION: LJF primarily inhibited biofilm formation through the reduction of EPS production, resulting in alterations in cell surface characteristics and growth retardation in biofilm formation cycles. Integrated transcriptomic and untargeted metabolomics analyses revealed that EPS production was modulated through two-component systems (TCS), quorum sensing (QS), and phosphotransferase system (PTS) pathways under LJF stress conditions. The sensing histidine kinase VicK was identified as an important target protein, as LJF caused its dysregulated expression and blocked the sensing of autoinducer II (AI-2). This led to the inhibition of response regulator transcriptional factors, down-regulated glycosyltransferase (Gtf) activity, and decreased production of water-insoluble glucans (WIG) and water-soluble glucans (WSG). This is the first exploration of the inhibitory effect and mechanism of LJF on S. mutans, providing a theoretical basis for the application of LJF in functional food, oral health care, and related areas.},
}

@article {pmid39026137,
year = {2024},
author = {Jagaba, AH and Abdulazeez, I and Lawal, DU and Affam, AC and Mu'azu, ND and Soja, UB and Usman, AK and Noor, A and Lim, JW and Aljundi, IH},
title = {A review on the application of biochar as an innovative and sustainable biocarrier material in moving bed biofilm reactors for dye removal from environmental matrices.},
journal = {Environmental geochemistry and health},
volume = {46},
number = {9},
pages = {333},
pmid = {39026137},
issn = {1573-2983},
mesh = {*Charcoal/chemistry ; *Biofilms ; *Coloring Agents/chemistry ; *Bioreactors ; Water Pollutants, Chemical ; Biodegradation, Environmental ; Waste Disposal, Fluid/methods ; },
abstract = {Dye decolorization through biological treatment techniques has been gaining momentum as it is based on suspended and attached growth biomass in both batch and continuous modes. Hence, this review focused on the contribution of moving bed biofilm reactors (MBBR) in dye removal. MBBR have been demonstrated to be an excellent technology for pollution extraction, load shock resistance, and equipment size and energy consumption reduction. The review went further to highlight different biocarrier materials for biofilm development this review identified biochar as an innovative and environmentally friendly material produced through the application of different kinds of reusable or recyclable wastes and biowastes. Biochar as a carbonized waste biomass could be a better competitor and environmentally friendly substitute to activated carbon given its lower mass costs. Biochar can be easily produced particularly in rural locations where there is an abundance of biomass-based trash. Given that circular bioeconomy lowers dependency on natural resources by turning organic wastes into an array of useful products, biochar empowers the creation of competitive goods. Thus, biochar was identified as a novel, cost-effective, and long-term management strategy since it brings about several essential benefits, including food security, climate change mitigation, biodiversity preservation, and sustainability improvement. This review concludes that integrating two treatment methods could greatly lead to better color, organic matter, and nutrients removal than a single biological MBBR treatment process.},
}

*Charcoal/chemistry
*Biofilms
*Coloring Agents/chemistry
*Bioreactors
Water Pollutants, Chemical
Biodegradation, Environmental
Waste Disposal, Fluid/methods

@article {pmid39024943,
year = {2024},
author = {Wang, X and Chen, C and Hu, J and Liu, C and Ning, Y and Lu, F},
title = {Current strategies for monitoring and controlling bacterial biofilm formation on medical surfaces.},
journal = {Ecotoxicology and environmental safety},
volume = {282},
number = {},
pages = {116709},
doi = {10.1016/j.ecoenv.2024.116709},
pmid = {39024943},
issn = {1090-2414},
abstract = {Biofilms, intricate microbial communities that attach to surfaces, especially medical devices, form an exopolysaccharide matrix, which enables bacteria to resist environmental pressures and conventional antimicrobial agents, leading to the emergence of multi-drug resistance. Biofilm-related infections associated with medical devices are a significant public health threat, compromising device performance. Therefore, developing effective methods for supervising and managing biofilm growth is imperative. This in-depth review presents a systematic overview of strategies for monitoring and controlling bacterial biofilms. We first outline the biofilm creation process and its regulatory mechanisms. The discussion then progresses to advancements in biosensors for biofilm detection and diverse treatment strategies. Lastly, this review examines the obstacles and new perspectives associated with this domain to facilitate the advancement of innovative monitoring and control solutions. These advancements are vital in combating the spread of multi drug-resistant bacteria and mitigating public health risks associated with infections from biofilm formation on medical instruments.},
}

@article {pmid39023225,
year = {2024},
author = {Zhao, L and Li, W and Liu, Y and Qi, Y and An, N and Yan, M and Wang, Z and Zhou, M and Yang, S},
title = {Designing Fast-Moving Antibacterial Microtorpedoes to Treat Lethal Bacterial Biofilm Infections.},
journal = {ACS nano},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsnano.4c04995},
pmid = {39023225},
issn = {1936-086X},
abstract = {Engineering fast-moving microrobot swarms that can physically disassemble bacterial biofilms and kill the bacteria released from the biofilms is a promising way to combat bacterial biofilm infections. Here, we report electrochemical design of Ag7O8NO3 microtorpedoes with outstanding antibacterial performance and meanwhile capable of moving at speeds of hundreds of body lengths per second in clinically used H2O2 aqueous solutions. These fast-moving antibacterial Ag7O8NO3 microtorpedoes could penetrate into and disintegrate the bacterial biofilms and, in turn, kill the bacteria released from the biofilms. Based on the understanding of the growth behavior of the microtorpedoes, we could fine-tune the morphology of the microtorpedoes to accelerate the moving speed and increase their penetration depth into the biofilms simply via controlling the potential waveforms. We further developed an automatic shaking method to selectively peel off the uniformly structured microtorpedoes from the electrode surface, realizing continuous electrochemical production of the microtorpedoes. Animal experiments proved that the microtorpedo swarms greatly increased the survival rate of the mice infected by lethal biofilms to >90%. We used the electrochemical method to design and massively produce uniformly structured fast-moving antibacterial microtorpedo swarms with application potentials in treatment of lethal bacterial biofilm infections.},
}

@article {pmid39023091,
year = {2024},
author = {Li, C and Gao, D and Li, C and Cheng, G and Zhang, L},
title = {Fighting against biofilm: The antifouling and antimicrobial material.},
journal = {Biointerphases},
volume = {19},
number = {4},
pages = {},
doi = {10.1116/6.0003695},
pmid = {39023091},
issn = {1559-4106},
mesh = {*Biofilms/drug effects/growth & development ; *Biofouling/prevention & control ; *Anti-Infective Agents/pharmacology/chemistry ; Biocompatible Materials/chemistry/pharmacology ; Anti-Bacterial Agents/pharmacology/chemistry ; },
abstract = {Biofilms are groups of microorganisms protected by self-secreted extracellular substances. Biofilm formation on the surface of biomaterial or engineering materials becomes a severe challenge. It has caused significant health, environmental, and societal concerns. It is believed that biofilms lead to life-threatening infection, medical implant failure, foodborne disease, and marine biofouling. To address these issues, tremendous effort has been made to inhibit biofilm formation on materials. Biofilms are extremely difficult to treat once formed, so designing material and coating bearing functional groups that are capable of resisting biofilm formation has attracted increasing attention for the last two decades. Many types of antibiofilm strategies have been designed to target different stages of biofilm formation. Development of the antibiofilm material can be classified into antifouling material, antimicrobial material, fouling release material, and integrated antifouling/antimicrobial material. This review summarizes relevant research utilizing these four approaches and comments on their antibiofilm properties. The feature of each method was compared to reveal the research trend. Antibiofilm strategies in fundamental research and industrial applications were summarized.},
}

*Biofilms/drug effects/growth & development
*Biofouling/prevention & control
*Anti-Infective Agents/pharmacology/chemistry
Biocompatible Materials/chemistry/pharmacology
Anti-Bacterial Agents/pharmacology/chemistry

@article {pmid39021701,
year = {2024},
author = {Andersen, JB and Rybtke, M and Tolker-Nielsen, T},
title = {The dynamics of biofilm development and dispersal should be taken into account when quantifying biofilm via the crystal violet microtiter plate assay.},
journal = {Biofilm},
volume = {8},
number = {},
pages = {100207},
pmid = {39021701},
issn = {2590-2075},
abstract = {The crystal violet microtiter plate biofilm assay is often used to compare the amount of biofilm formed by a mutant versus wild-type or a compound-treated biofilm versus the non-treatment control. In many of these studies the amount of biofilm is assessed only at one single time point. However, if the dynamics of biofilm development of the mutant (or compound-treated biofilm) is different than that of the wild-type (or non-treatment control), then biofilm quantification at a single time point may give misleading results. To overcome this shortcoming of the common biofilm quantification technique, we recommend to use a serial dilution-based crystal violet microtiter plate biofilm assay for easy assessment of the dynamics of biofilm development and dispersal. We demonstrate that the dilution-resolved crystal violet assay displays the dynamics of Pseudomonas aeruginosa biofilm development and dispersal as efficient as a time-resolved crystal violet assay. In addition, focusing on mutants of different parts of the c-di-GMP signaling system in P. aeruginosa, we provide an example illustrating the need to assess biofilm dynamics instead of quantifying biofilm biomass at a single time point.},
}

@article {pmid39021314,
year = {2024},
author = {Gomes Guimarães, G and Alves, F and Gonçalves, I and Silva E Carvalho, I and Toneth Ponce Ayala, E and Pratavieira, S and Salvador Bagnato, V},
title = {The synergistic effect of photodynamic and sonodynamic inactivation against Candida albicans biofilm.},
journal = {Journal of biophotonics},
volume = {},
number = {},
pages = {e202400190},
doi = {10.1002/jbio.202400190},
pmid = {39021314},
issn = {1864-0648},
support = {001//Coordenação de Aperfeiçoamento Pessoal de Nível Superior (CAPES)/ ; 465 360/2014-9//National Council for Scientific and Technological Development-CNPq/ ; 306919/2019-2//National Council for Scientific and Technological Development-CNPq/ ; 305072/2022-6//National Council for Scientific and Technological Development-CNPq/ ; 131017/2022-5//National Council for Scientific and Technological Development-CNPq/ ; 440237/2021-1//National Council for Scientific and Technological Development-CNPq/ ; 2013/07276-1//São Paulo Research Foundation (FAPESP)/ ; 2014/50857-8//São Paulo Research Foundation (FAPESP)/ ; 2021/01324-0//São Paulo Research Foundation (FAPESP)/ ; },
abstract = {Candida albicans biofilm can cause diseases that are resistant to conventional antifungal agents. Photodynamic (PDI), sonodynamic (SDI), and sonophotodynamic (SPDI) inactivation have arisen as promising antimicrobial strategies. This study evaluated these treatments mediated by curcumin against C. albicans biofilms. For this, C. albicans biofilms were submitted to PDI, SDI, or SPDI with different light and ultrasound doses, then, the viability assay was performed to measure the effectiveness. Finally, a mathematical model was suggested to fit acquired experimental data and understand the synergistic effect of light and ultrasound in different conditions. The results showed that SPDI, PDI, and SDI reduced the viability in 6 ± 1; 1 ± 1; and 2 ± 1 log, respectively, using light at 60 J/cm[2], ultrasound at 3 W/cm[2], and 80 μM of curcumin. The viability reduction was proportional to the ultrasound and light doses delivered. These results encourage the use of SPDI for the control of microbial biofilm.},
}

@article {pmid39021233,
year = {2024},
author = {Emiliano, JVDS and Fusieger, A and Camargo, AC and Rodrigues, FFDC and Nero, LA and Perrone, ÍT and Carvalho, AF},
title = {Staphylococcus aureus in Dairy Industry: Enterotoxin Production, Biofilm Formation, and Use of Lactic Acid Bacteria for Its Biocontrol.},
journal = {Foodborne pathogens and disease},
volume = {},
number = {},
pages = {},
doi = {10.1089/fpd.2023.0170},
pmid = {39021233},
issn = {1556-7125},
abstract = {Staphylococcus aureus is a well-known pathogen capable of producing enterotoxins during bacterial growth in contaminated food, and the ingestion of such preformed toxins is one of the major causes of food poisoning around the world. Nowadays 33 staphylococcal enterotoxins (SEs) and SE-like toxins have been described, but nearly 95% of confirmed foodborne outbreaks are attributed to classical enterotoxins SEA, SEB, SEC, SED, and SEE. The natural habitat of S. aureus includes the skin and mucous membranes of both humans and animals, allowing the contamination of milk, its derivatives, and the processing facilities. S. aureus is well known for the ability to form biofilms in food processing environments, which contributes to its persistence and cross-contamination in food. The biocontrol of S. aureus in foods by lactic acid bacteria (LAB) and their bacteriocins has been studied for many years. Recently, LAB and their metabolites have also been explored for controlling S. aureus biofilms. LAB are used in fermented foods since in ancient times and nowadays characterized strains (or their purified bacteriocin) can be intentionally added to prolong food shelf-life and to control the growth of potentially pathogenic bacteria. Regarding the use of these microorganism and their metabolites (such as organic acids and bacteriocins) to prevent biofilm development or for biofilm removal, it is possible to conclude that a complex network behind the antagonistic activity remains poorly understood at the molecular level. The use of approaches that allow the characterization of these interactions is necessary to enhance our understanding of the mechanisms that govern the inhibitory activity of LAB against S. aureus biofilms in food processing environments.},
}

@article {pmid39020257,
year = {2024},
author = {Zarei, M and Ghahfarokhi, MG and Sabaeian, M and Sepahi, M and Alirezaie, S and Mohebi, M},
title = {Effect of plasma-activated water on planktonic and biofilm cells of Vibrio parahaemolyticus strains isolated from cutting board surfaces in retail seafood markets.},
journal = {Journal of applied microbiology},
volume = {},
number = {},
pages = {},
doi = {10.1093/jambio/lxae182},
pmid = {39020257},
issn = {1365-2672},
abstract = {AIMS: This research aimed to analyze cutting board surfaces in seafood markets to find Vibrio parahaemolyticus, assess the isolates' ability to form biofilms, generate and evaluate characteristics of plasma-activated water (PAW), and compare the effect of PAW on planktonic and biofilm cells of the isolated V. parahaemolyticus strains.

METHODS AND RESULTS: A total of 11 V. parahaemolyticus strains were isolated from 8.87% of the examined cutting boards. Biofilm-forming ability was evaluated for these isolates at temperatures of 10, 20, and 30°C using crystal violet staining. Four strains with the highest biofilm potential were selected for further analysis. The pH of the PAW used in the study was 3.41±0.04, and the initial concentrations of hydrogen peroxide, nitrate, and nitrite were 108±9.6 µM, 742±61 µM, and 36.3±2.9 µM, respectively. However, these concentrations decreased significantly within 3-4 days during storage at room temperature. PAW exhibited significant antimicrobial effects on V. parahaemolyticus planktonic cells, reducing viable bacteria up to 4.54 log CFU/ml within 20 minutes. PAW also reduced the number of biofilm cells on stainless steel (up to 3.55 log CFU/cm2) and high-density polyethylene (up to 3.06 log CFU/cm2) surfaces, although to a lesser extent than planktonic cells.

CONCLUSIONS: PAW exhibited significant antibacterial activity against V. parahaemolyticus cells, although its antibacterial properties diminished over time. Furthermore, the antibacterial activity of PAW against biofilm cells of V. parahaemolyticus was less pronounced compared to the planktonic cells. Therefore, the actual effectiveness of PAW in seafood processing environments can be affected by biofilms that may form on various surfaces such as cutting boards if they are not cleaned properly.},
}

@article {pmid39020245,
year = {2024},
author = {Huang, Z and Li, Y and Yin, W and Raby, RBN and Liang, H and Yu, B},
title = {A magnetic-guided nano-antibacterial platform for alternating magnetic field controlled vancomycin release in staphylococcus aureus biofilm eradication.},
journal = {Drug delivery and translational research},
volume = {},
number = {},
pages = {},
pmid = {39020245},
issn = {2190-3948},
support = {81974323//National Natural Science Foundation of China/ ; 2020A1515010055//Natural Science Foundation of Guangdong Province/ ; zdyf201993//Science and Technology Development Plan Project of Chenzhou/ ; },
abstract = {Bacterial resilience within biofilms, rendering them up to 1000 times more resistant to antibiotic drugs, poses a formidable challenge. This study introduces a targeted biofilm eradication strategy, termed "target-penetration-killing-eradication", implemented through magnetic micro-robotic technology. Specifically, we present the development of a magnetic-guided nano-antibacterial platform designed for alternating magnetic field (AMF) controlled vancomycin release in the eradication of Staphylococcus aureus biofilms. To address the issue of premature vancomycin release in physiological conditions, we employed a temperature-sensitive linking agent, 4,4'-azobis(4-cyano valeric acid), facilitating the conjugation of vancomycin onto Fe3O4/CS nanocomposites, resulting in the novel construct Fe3O4@CS-ACVA-VH. The release mechanism adheres to first-order kinetics and Fickian diffusion, with each 10-min AMF treatment releasing approximately 8.4 ± 1.1% of vancomycin. The potency of vancomycin in the release solution was similar to that of the original drug (MIC: 7.4 ± 3.5 vs. 5.6 μg/mL). Fe3O4@CS-ACVA-VH exhibited sustained antibacterial efficacy, inhibiting bacterial growth for four consecutive days and preventing the formation of bacterial biofilms on its surface. Contact-inhibition bacterial activity of Fe3O4@CS-ACVA-VH against S. aureus was 0.046875 mg/mL. Conceptually validating our approach, we emphasize Fe3O4@CS-ACVA-VH's exceptional ability to penetrate S. aureus biofilms under static magnetic field attraction. Furthermore, the nano-platform offers the unique advantage of on-demand vancomycin release through alternating magnetic field stimulation, effectively clearing a larger biofilm area. This multifunctional nano-platform demonstrates magnetic-guided biofilm penetration followed by controlled vancomycin release, presenting a promising strategy for enhanced biofilm eradication.},
}

@article {pmid39019725,
year = {2024},
author = {Bueno, FL and Badaró, MM and Pagnano, VO and Curylofo, PA and Oliveira, VC and Macedo, AP and Watanabe, E and Paranhos, HFO and Silva-Lovato, CH},
title = {Effect of disinfectants on multispecies biofilm, the physical and mechanical properties of polymethyl methacrylate, and the corrosion of cobalt chromium alloy.},
journal = {The Journal of prosthetic dentistry},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.prosdent.2024.06.019},
pmid = {39019725},
issn = {1097-6841},
abstract = {STATEMENT OF PROBLEM: The optimal disinfection protocol that controls adverse effects and promotes effective antimicrobial action on removable prostheses is unclear.

PURPOSE: This in vitro study investigated the effect of disinfectant solutions on the biological, physical, mechanical, and chemical properties of removable prosthesis materials.

MATERIAL AND METHODS: Specimens of polymethyl methacrylate (PMMA) and cobalt chromium (Co-Cr) alloy were immersed in distilled water (PMMA) or artificial saliva (Co-Cr) as the control and in 0.25% sodium hypochlorite (NaOCl0.25%), 0.5% chloramine T (CT0.5%), and 0.15% Triclosan (TR0.15%). The antibiofilm activity was evaluated by microbial load and cell metabolisms of the mixed biofilm. Physical (color change, sorption, solubility, and surface roughness), mechanical (hardness, flexural, and impact strength), and chemical (corrosion) properties were analyzed before and after simulating a 5-year immersion. Laser confocal microscopy, scanning electron microscopy (SEM), and dispersive energy spectroscopy (EDS) complemented the analyses. The data were analyzed by using the Mann-Whitney U test, Kruskal-Wallis with Dunn posttests, 1-way ANOVA, and repeated measures ANOVA (α=.05).

RESULTS: All solutions were effective against bacteria, but only NaOCl0.25% eliminated Candida spp. TR0.15%, and CT0.5% increased cell metabolisms. For interaction (time and solution), there was a reduction in PMMA hardness in the control and TR0.15%. Color, sorption, solubility, and flexural strength did not change. CT0.5% and TR0.15% were similar for impact resistance. CT0.5% caused the lowest roughness. NaOCl0.25% showed the greatest corrosive potential. Dark spots were seen under SEM in Co-Cr stored with NaOCl0.25% and TR0.15%. EDS indicated different proportions of oxygen, cobalt, chromium, and molybdenum.

CONCLUSIONS: NaOCl0.25% had the best antimicrobial action. CT0.5% and TR0.15% have potential. Hardness and roughness changes were clinically acceptable, and the other properties remained unchanged. All the solutions caused color changes. NaOCl0.25% was unsatisfactory for use with Co-Cr, CT0.5% was intermediate, and TR0.15% was suitable.},
}

@article {pmid39019323,
year = {2024},
author = {Siu, SY and Pudipeddi, A and Vishwanath, V and Cheng Lee, AH and Tin Cheung, AW and Pan Cheung, GS and Neelakantan, P},
title = {Effect of Novel and Traditional Intracanal Medicaments on Biofilm Viability and Composition.},
journal = {Journal of endodontics},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.joen.2024.07.003},
pmid = {39019323},
issn = {1878-3554},
abstract = {INTRODUCTION: The aim of this study was to test the hypothesis that a combination of D-amino acids (DAA) and trans-cinnamaldehyde (TC) demonstrates superior antibiofilm activity to calcium hydroxide (CH) and untreated controls.

METHODS: In this 3-part in vitro study, the concentration of DAAs (D-methionine, D-leucine, D-tyrosine, and D-tryptophan) that would significantly decrease Enterococcus faecalis and Actinomyces naeslundii biofilm biomass was first determined. Then, the effect of TC + selected DAAs on polymicrobial biofilms was characterized by quantifying the biomass and biofilm viability. Finally, the antibiofilm effects of TC+DAA was compared with CH and untreated controls by (i) determining bacterial viability and (ii) quantifying biofilm matrix composition using selective fluorescence-binding analysis. Statistical analysis was performed using one-way ANOVA and appropriate multiple comparisons test, with P<.05 considered as statistically significant.

RESULTS: TC (0.06%) + D-tyrosine (1 mM) + D-tryptophan (25 mM) significantly reduced the biomass and biofilm viability compared to the control (P<.05). While no significant difference was observed between TC+DAA and CH in the cultivable bacterial counts (P>.05), confocal microscopy demonstrated a significantly greater percentage of dead bacteria in TC+DAA-treated biofilms compared to CH and the control (P<.05). TC+DAA significantly decreased the biovolume and all the examined components of the biofilm matrix quantity compared to the control, while CH significantly reduced only the exopolysaccharide quantity (P<.05).

CONCLUSION: TC + D-tyrosine + D-tryptophan demonstrated superior antibiofilm activity (biofilm bacterial killing and reduction of matrix quantity) to CH and has potential to be developed as an intracanal medicament.},
}

@article {pmid39017726,
year = {2024},
author = {Carvalho, FS and Tarabal, VS and Livio, DF and Cruz, LF and Monteiro, APF and Parreira, AG and Guimarães, PPG and Scheuerman, K and Chagas, RCR and da Silva, JA and Gonçalves, DB and Granjeiro, JM and Sinisterra, RD and Segura, MEC and Granjeiro, PA},
title = {Production and characterization of the lipopeptide with anti-adhesion for oral biofilm on the surface of titanium for dental implants.},
journal = {Archives of microbiology},
volume = {206},
number = {8},
pages = {354},
pmid = {39017726},
issn = {1432-072X},
support = {APQ- 00855-19//Fundação de Amparo à Pesquisa do Estado de Minas Gerais/ ; 306076/2017-9//Conselho Nacional de Desenvolvimento Científico e Tecnológico/ ; 001//Coordenação de Aperfeiçoamento de Pessoal de Nível Superior/ ; },
mesh = {*Titanium/pharmacology/chemistry ; *Biofilms/drug effects/growth & development ; *Bacterial Adhesion/drug effects ; *Dental Implants/microbiology ; *Lipopeptides/pharmacology ; *Microbial Sensitivity Tests ; Humans ; Anti-Bacterial Agents/pharmacology ; Staphylococcus aureus/drug effects/physiology ; Bacillus subtilis/drug effects ; Porphyromonas gingivalis/drug effects/physiology/growth & development ; Aggregatibacter actinomycetemcomitans/drug effects ; Surface Properties ; Fibroblasts/drug effects ; Fusobacterium nucleatum/drug effects ; Cell Survival/drug effects ; Osteoblasts/drug effects ; Surface-Active Agents/pharmacology ; },
abstract = {Titanium implants are subject to bacterial adhesion and peri-implantitis induction, and biosurfactants bring a new alternative to the fight against infections. This work aimed to produce and characterize the biosurfactant from Bacillus subtilis ATCC 19,659, its anti-adhesion and antimicrobial activity, and cell viability. Anti-adhesion studies were carried out against Streptococcus sanguinis, Staphylococcus aureus, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Proteus mirabilis as the minimum inhibitory concentration and the minimum bactericidal concentration. Cell viability was measured against osteoblast and fibroblast cells. The biosurfactant was classified as lipopeptide, with critical micelle concentration at 40 µg mL[- 1], and made the titanium surface less hydrophobic. The anti-adhesion effect was observed for Staphylococcus aureus and Streptococcus sanguinis with 54% growth inhibition and presented a minimum inhibitory concentration of 15.7 µg mL[- 1] for Streptococcus sanguinis and Aggregatibacter actinomycetemcomitans. The lipopeptide had no cytotoxic effect and demonstrated high potential application against bacterial biofilms.},
}

*Titanium/pharmacology/chemistry
*Biofilms/drug effects/growth & development
*Bacterial Adhesion/drug effects
*Dental Implants/microbiology
*Lipopeptides/pharmacology
*Microbial Sensitivity Tests
Humans
Anti-Bacterial Agents/pharmacology
Staphylococcus aureus/drug effects/physiology
Bacillus subtilis/drug effects
Porphyromonas gingivalis/drug effects/physiology/growth & development
Aggregatibacter actinomycetemcomitans/drug effects
Surface Properties
Fibroblasts/drug effects
Fusobacterium nucleatum/drug effects
Cell Survival/drug effects
Osteoblasts/drug effects
Surface-Active Agents/pharmacology

@article {pmid39015665,
year = {2024},
author = {Tian, Z and Xiong, Y and Li, G and Cao, X and Li, X and Du, C and Zhang, L},
title = {Food wastewater treatment using a hybrid biofilm reactor: nutrient removal performance and functional microorganisms on filler biofilm and suspended sludge.},
journal = {RSC advances},
volume = {14},
number = {31},
pages = {22470-22479},
pmid = {39015665},
issn = {2046-2069},
abstract = {In this study, a laboratory-scale hybrid biofilm reactor (HBR) was constructed to treat food wastewater (FWW) before it is discharged into the sewer. The chemical oxygen demand (COD) of 29 860 mg L[-1] in FWW was degraded to 200-350 mg L[-1] using the HBR under the operating parameters of COD load 1.68 kg m[-3] d[-1], hydraulic retention time (HRT) of 426.63 h, dissolved oxygen (DO) of 8-9 mg L[-1], and temperature of 22-23 °C. The biomass of biofilm on the surface of filler was 2.64 g L[-1] for column A and 0.91 g L[-1] for column O. Microbial analysis revealed richer and more diverse microorganisms in filler biofilms compared to those in suspended sludge. The hybrid filler was conducive to the development of functional microbial species, including phyla Firmicutes, Actinobacteriota, and Chloroflexi, and genus level norank_f_JG30-KF-CM45, which will improve FWW treatment efficiency. Moreover, the microorganisms on the filler biofilm had more connections and relationships than those in the suspended sludge. The combination of an up-flow anaerobic sludge bed (UASB) and HBR was demonstrated to be an economical strategy for practical applications as a shorter HRT of 118.34 h could be obtained. Overall, this study provides reliable data and a theoretical basis for the application of HBR and FWW treatments.},
}

@article {pmid39014985,
year = {2024},
author = {Duggan DiDominic, KL and Shapleigh, JP and Walter, MT and Wang, YS and Reid, MC and Regan, JM},
title = {Microbial diversity and gene abundance in denitrifying bioreactors: A comparison of the woodchip surface biofilm versus the interior wood matrix.},
journal = {Journal of environmental quality},
volume = {},
number = {},
pages = {},
doi = {10.1002/jeq2.20600},
pmid = {39014985},
issn = {1537-2537},
support = {1922551//National Science Foundation Research Traineeship (NRT) Program/ ; 2019-67019-29461//U.S. Department of Agriculture/ ; },
abstract = {Excessive amounts of nitrogen (N) and phosphorus (P) can lead to eutrophication in water sources. Woodchip bioreactors have shown success in removing N from agricultural runoff, but less is known regarding P removal. Woodchip bioreactors are subsurface basins filled with woodchips installed downgradient of agricultural land to collect and treat drainage runoff. Microorganisms use the woodchips as a carbon (C) source to transform N in the runoff, with unresolved biological impacts on P. This study aims to explore microbial communities present in the bioreactor and determine whether milling woodchips to probe the microbial communities within them reveals hidden microbial diversities or potential activities. Metagenomic sequencing and bioinformatic analyses were performed on six woodchip samples (i.e., three unmilled and three milled) collected from a 10-year-old woodchip bioreactor treating agricultural tile drainage. All samples had similar DNA purity, yield, quality, and microbial diversity regardless of milling. However, when sequences were aligned against various protein libraries, our results indicated greater relative abundance of denitrification and P transformation proteins on the outside of the woodchips (unmilled), while the interior of woodchips (milled) exhibited more functional gene abundance for carbohydrate breakdown. Thus, it may be important to characterize microbial communities both within woodchips, and on woodchip surfaces, to gain a more holistic understanding of coupled biogeochemical cycles on N, P, and C in woodchip bioreactors. Based on these findings, we advise that future microbial research on woodchips (and potentially other permeable organic materials) examine both the surface biofilm and the interior organic material during initial studies. Once researchers determine where specific proteins or enzymes of interest are most prevalent, subsequent studies may then focus on either one or both aspects, as needed.},
}

@article {pmid39012538,
year = {2024},
author = {Tang, D and Lin, Y and Yao, H and Liu, Y and Xi, Y and Li, M and Mao, A},
title = {Effect of L-HSL on biofilm and motility of Pseudomonas aeruginosa and its mechanism.},
journal = {Applied microbiology and biotechnology},
volume = {108},
number = {1},
pages = {418},
pmid = {39012538},
issn = {1432-0614},
support = {12065001//12065001/ ; 32160025//32160025/ ; },
mesh = {*Pseudomonas aeruginosa/drug effects/physiology/genetics ; *Biofilms/drug effects/growth & development ; *Quorum Sensing/drug effects ; *Caenorhabditis elegans/drug effects/microbiology ; Animals ; *4-Butyrolactone/analogs & derivatives/pharmacology/metabolism ; Anti-Bacterial Agents/pharmacology ; Gene Expression Profiling ; Homoserine/analogs & derivatives/metabolism/pharmacology ; Gene Expression Regulation, Bacterial/drug effects ; },
abstract = {Pseudomonas aeruginosa (P. aeruginosa) biofilm formation is a crucial cause of enhanced antibiotic resistance. Quorum sensing (QS) is involved in regulating biofilm formation; QS inhibitors block the QS signaling pathway as a new strategy to address bacterial resistance. This study investigated the potential and mechanism of L-HSL (N-(3-cyclic butyrolactone)-4-trifluorophenylacetamide) as a QS inhibitor for P. aeruginosa. The results showed that L-HSL effectively inhibited the biofilm formation and dispersed the pre-formed biofilm of P. aeruginosa. The production of extracellular polysaccharides and the motility ability of P. aeruginosa were suppressed by L-HSL. C. elegans infection experiment showed that L-HSL was non-toxic and provided protection to C. elegans against P. aeruginosa infection. Transcriptomic analysis revealed that L-HSL downregulated genes related to QS pathways and biofilm formation. L-HSL exhibits a promising potential as a therapeutic drug for P. aeruginosa infection. KEY POINTS: • Chemical synthesis of N-(3-cyclic butyrolactone)-4-trifluorophenylacetamide, named L-HSL. • L-HSL does not generate survival pressure on the growth of P. aeruginosa and can inhibit the QS system. • KEGG enrichment analysis found that after L-HSL treatment, QS-related genes were downregulated.},
}

*Pseudomonas aeruginosa/drug effects/physiology/genetics
*Biofilms/drug effects/growth & development
*Quorum Sensing/drug effects
*Caenorhabditis elegans/drug effects/microbiology
Animals
*4-Butyrolactone/analogs & derivatives/pharmacology/metabolism
Anti-Bacterial Agents/pharmacology
Gene Expression Profiling
Homoserine/analogs & derivatives/metabolism/pharmacology
Gene Expression Regulation, Bacterial/drug effects

@article {pmid39012148,
year = {2024},
author = {Ayala, JC and Balthazar, JT and Shafer, WM},
title = {Transcriptional responses of Neisseria gonorrhoeae to glucose and lactate: implications for resistance to oxidative damage and biofilm formation.},
journal = {mBio},
volume = {},
number = {},
pages = {e0176124},
doi = {10.1128/mbio.01761-24},
pmid = {39012148},
issn = {2150-7511},
abstract = {Understanding how bacteria adapt to different environmental conditions is crucial for advancing knowledge regarding pathogenic mechanisms that operate during infection as well as efforts to develop new therapeutic strategies to cure or prevent infections. Here, we investigated the transcriptional response of Neisseria gonorrhoeae, the causative agent of gonorrhea, to L-lactate and glucose, two important carbon sources found in the host environment. Our study revealed extensive transcriptional changes that gonococci make in response to L-lactate, with 37% of the gonococcal transcriptome being regulated, compared to only 9% by glucose. We found that L-lactate induces a transcriptional program that would negatively impact iron transport, potentially limiting the availability of labile iron, which would be important in the face of the multiple hydrogen peroxide attacks encountered by gonococci during its lifecycle. Furthermore, we found that L-lactate-mediated transcriptional response promoted aerobic respiration and dispersal of biofilms, contrasting with an anaerobic condition previously reported to favor biofilm formation. Our findings suggest an intricate interplay between carbon metabolism, iron homeostasis, biofilm formation, and stress response in N. gonorrhoeae, providing insights into its pathogenesis and identifying potential therapeutic targets.IMPORTANCEGonorrhea is a prevalent sexually transmitted infection caused by the human pathogen Neisseria gonorrhoeae, with ca. 82 million cases reported worldwide annually. The rise of antibiotic resistance in N. gonorrhoeae poses a significant public health threat, highlighting the urgent need for alternative treatment strategies. By elucidating how N. gonorrhoeae responds to host-derived carbon sources such as L-lactate and glucose, this study offers insights into the metabolic adaptations crucial for bacterial survival and virulence during infection. Understanding these adaptations provides a foundation for developing novel therapeutic approaches targeting bacterial metabolism, iron homeostasis, and virulence gene expression. Moreover, the findings reported herein regarding biofilm formation and L-lactate transport and metabolism contribute to our understanding of N. gonorrhoeae pathogenesis, offering potential avenues for preventing and treating gonorrhea infections.},
}

@article {pmid39012136,
year = {2024},
author = {Motta, EVS and de Jong, TK and Gage, A and Edwards, JA and Moran, NA},
title = {Glyphosate effects on growth and biofilm formation in bee gut symbionts and diverse associated bacteria.},
journal = {Applied and environmental microbiology},
volume = {},
number = {},
pages = {e0051524},
doi = {10.1128/aem.00515-24},
pmid = {39012136},
issn = {1098-5336},
abstract = {UNLABELLED: Biofilm formation is a common adaptation enabling bacteria to thrive in various environments and withstand external pressures. In the context of host-microbe interactions, biofilms play vital roles in establishing microbiomes associated with animals and plants and are used by opportunistic microbes to facilitate survival within hosts. Investigating biofilm dynamics, composition, and responses to environmental stressors is crucial for understanding microbial community assembly and biofilm regulation in health and disease. In this study, we explore in vivo colonization and in vitro biofilm formation abilities of core members of the honey bee (Apis mellifera) gut microbiota. Additionally, we assess the impact of glyphosate, a widely used herbicide with antimicrobial properties, and a glyphosate-based herbicide formulation on growth and biofilm formation in bee gut symbionts as well as in other biofilm-forming bacteria associated with diverse animals and plants. Our results demonstrate that several strains of core bee gut bacterial species can colonize the bee gut, which probably depends on their ability to form biofilms. Furthermore, glyphosate exposure elicits variable effects on bacterial growth and biofilm formation. In some instances, the effects correlate with the bacteria's ability to encode a susceptible or tolerant version of the enzyme inhibited by glyphosate in the shikimate pathway. However, in other instances, no such correlation is observed. Testing the herbicide formulation further complicates comparisons, as results often diverge from glyphosate exposure alone, suggesting that co-formulants influence bacterial growth and biofilm formation. These findings highlight the nuanced impacts of environmental stressors on microbial biofilms, with both ecological and host health-related implications.

IMPORTANCE: Biofilms are essential for microbial communities to establish and thrive in diverse environments. In the honey bee gut, the core microbiota member Snodgrassella alvi forms biofilms, potentially aiding the establishment of other members and promoting interactions with the host. In this study, we show that specific strains of other core members, including Bifidobacterium, Bombilactobacillus, Gilliamella, and Lactobacillus, also form biofilms in vitro. We then examine the impact of glyphosate, a widely used herbicide that can disrupt the bee microbiota, on bacterial growth and biofilm formation. Our findings demonstrate the diverse effects of glyphosate on biofilm formation, ranging from inhibition to enhancement, reflecting observations in other beneficial or pathogenic bacteria associated with animals and plants. Thus, glyphosate exposure may influence bacterial growth and biofilm formation, potentially shaping microbial establishment on host surfaces and impacting health outcomes.},
}

@article {pmid39012102,
year = {2024},
author = {Conway, J and Delanois, RE and Mont, MA and Stavrakis, A and McPherson, E and Stolarski, E and Incavo, S and Oakes, D and Salvagno, R and Adams, JS and Kisch-Hancock, A and Tenorio, E and Leighton, A and Ryser, S and Kauvar, LM and Bernthal, NM},
title = {Phase 1 study of the pharmacokinetics and clinical proof-of-concept activity of a biofilm-disrupting human monoclonal antibody in patients with chronic prosthetic joint infection of the knee or hip.},
journal = {Antimicrobial agents and chemotherapy},
volume = {},
number = {},
pages = {e0065524},
doi = {10.1128/aac.00655-24},
pmid = {39012102},
issn = {1098-6596},
abstract = {UNLABELLED: We report the results of a first-in-human phase 1 clinical study to evaluate TRL1068, a native human monoclonal antibody that disrupts bacterial biofilms with broad-spectrum activity against both Gram-positive and Gram-negative species. The study population consisted of patients with chronic periprosthetic joint infections (PJIs) of the knee or hip, including both monomicrobial and polymicrobial infections, that are highly resistant to antibiotics due to biofilm formation. TRL1068 was administered via a single pre-surgical intravenous infusion in three sequentially ascending dose groups (6, 15, and 30 mg/kg). Concomitant perioperative antibiotics were pathogen-targeted as prescribed by the treating physician. In this double-blinded study, 4 patients were randomized to receive placebo and 11 patients to receive TRL1068 on day 1, as well as targeted antibiotics for 7 days prior to the scheduled removal of the infected implant and placement of an antibiotic-eluting spacer as the first stage of the standard of care two-stage exchange arthroplasty. No adverse events attributable to TRL1068 were reported. TRL1068 serum half-life was 15-18 days. At day 8, the concentration in synovial fluid was approximately 60% of the blood level and thus at least 15-fold above the threshold for biofilm-disrupting activity in vitro. Explanted prostheses were sonicated to release adherent bacteria for culture, with elimination of the implant bacteria observed in 3 of the 11 patients who received TRL1068, which compares favorably to prior PJI treatments. None of the patients who received TRL1068 had a relapse of the original infection by the end of the study (day 169).

CLINICAL TRIALS: This study is registered with ClinicalTrials.gov as NCT04763759.},
}

@article {pmid39011568,
year = {2024},
author = {Martins, PHR and Romo, AIB and Gouveia, FS and Paz, IA and Nascimento, NRF and Andrade, AL and Rodríguez-López, J and de Vasconcelos, MA and Teixeira, EH and Moraes, CAF and Lopes, LGF and Sousa, EHS},
title = {Anti-bacterial, anti-biofilm and synergistic effects of phenazine-based ruthenium(II) complexes.},
journal = {Dalton transactions (Cambridge, England : 2003)},
volume = {},
number = {},
pages = {},
doi = {10.1039/d4dt01033g},
pmid = {39011568},
issn = {1477-9234},
abstract = {Antimicrobial resistance has become a global threat to human health, which is coupled with the lack of novel drugs. Metallocompounds have emerged as promising diverse scaffolds for the development of new antibiotics. Herein, we prepared some metal compounds mainly focusing on cis-[Ru(bpy)(dppz)(SO3)(NO)](PF6) (PR02, bpy = 2,2'-bipyridine, dppz = dipyrido[3,2-a:2',3'-c]phenazine), in which phenazinic and nitric oxide ligands along with sulfite conferred some key properties. This compound exhibited a redox potential for bound NO[+/0] of -0.252 V (vs. Ag|AgCl) and a high pH for nitrosyl-nitro conversion of 9.16, making the nitrosyl ligand the major species. These compounds were still able to bind to DNA structures. Interestingly, reduced glutathione (GSH) was unable to promote significant NO/HNO release, an uncommon feature of many similar systems. However, this reducing agent was essential to generate superoxide radicals. Antimicrobial studies were carried out using six bacterial strains, where none or very low activity was observed for Gram-negative bacteria. However, PR02 and PR (cis-[Ru(bpy)(dppz)Cl2]) showed high antibacterial activity in some Gram-positive strains (MBC for S. aureus up to 4.9 μmol L[-1]), where the activity of PR02 was similar to or at least 4-fold better than that of PR. Besides, PR02 showed capacity to inhibit bacterial biofilm formation, a major health issue leading to bacterial tolerance to antibiotics. Interestingly, we also showed that PR02 can function in synergism with the known antibiotic ampicillin, improving their action up to 4-fold even against resistant strains. Altogether, these results showed that PR02 is a promising antimicrobial nitrosyl ruthenium compound combining features beyond its killing action, which deserves further biological studies.},
}

@article {pmid39011151,
year = {2024},
author = {Macià, MD and Borghi, E and Oliver, A},
title = {Eurobiofilms 2022: A translational perspective of biofilm-related persistent infections.},
journal = {Biofilm},
volume = {7},
number = {},
pages = {100168},
pmid = {39011151},
issn = {2590-2075},
}

@article {pmid39010993,
year = {2024},
author = {El-Subeyhi, M and Hamid, LL and Gayadh, EW and Saod, WM and Ramizy, A},
title = {Biogenic Synthesis and Characterisation of Novel Potassium Nanoparticles by Capparis spinosa Flower Extract and Evaluation of Their Potential Antibacterial, Anti-biofilm and Antibiotic Development.},
journal = {Indian journal of microbiology},
volume = {64},
number = {2},
pages = {548-557},
pmid = {39010993},
issn = {0046-8991},
abstract = {Scientific researches on the synthesis, characterisation, and biological activity of potassium nanoparticles (K NPs) are extremely rare. In our study, we successfully synthesised a novel form of K NPs using Capparis spinosa (C. spinosa) flower extract as a reducing and capping agent. The formation of K NPs in new form (K2O NPs) was confirmed by UV-vis and XRD spectra. Furthermore, the FTIR results indicated the presence of specific active biomolecules in the C. spinosa extract which played a crucial role in reducing and stabilising K2O NPs. SEM imaging demonstrated that the K2O NPs exhibited irregular shapes with nanosizes ranging between 25 and 95 nm. Remarkably, the biosynthesised K2O NPs displayed considerable antibacterial activity against a wide range of multidrug-resistant (MDR) pathogenic bacteria. K2O NPs demonstrated considerable anti-biofilm activity against preformed biofilms produced by MDR bacteria. Combining K2O NPs with conventional antibiotics greatly improved their efficacy in compacting the MDR bacterial strains. Industrially, bulk form of potassium oxides was commonly used in the preparation of various antimicrobial compounds such as detergents, bleach, and oxidising solutions. The synthesis of potassium oxide in nanoform has shown remarkable biological efficacy, making it a promising therapeutic approach for pharmaceutical and medical applications.},
}

@article {pmid39009474,
year = {2024},
author = {Mahto, KU and Das, S},
title = {Electroactive biofilm communities in microbial fuel cells for the synergistic treatment of wastewater and bioelectricity generation.},
journal = {Critical reviews in biotechnology},
volume = {},
number = {},
pages = {1-20},
doi = {10.1080/07388551.2024.2372070},
pmid = {39009474},
issn = {1549-7801},
abstract = {Increasing industrialization and urbanization have contributed to a significant rise in wastewater discharge and exerted extensive pressure on the existing natural energy resources. Microbial fuel cell (MFC) is a sustainable technology that utilizes wastewater for electricity generation. MFC comprises a bioelectrochemical system employing electroactive biofilms of several aerobic and anaerobic bacteria, such as Geobacter sulfurreducens, Shewanella oneidensis, Pseudomonas aeruginosa, and Ochrobacterum pseudiintermedium. Since the electroactive biofilms constitute a vital part of the MFC, it is crucial to understand the biofilm-mediated pollutant metabolism and electron transfer mechanisms. Engineering electroactive biofilm communities for improved biofilm formation and extracellular polymeric substances (EPS) secretion can positively impact the bioelectrochemical system and improve fuel cell performance. This review article summarizes the role of electroactive bacterial communities in MFC for wastewater treatment and bioelectricity generation. A significant focus has been laid on understanding the composition, structure, and function of electroactive biofilms in MFC. Various electron transport mechanisms, including direct electron transfer (DET), indirect electron transfer (IET), and long-distance electron transfer (LDET), have been discussed. A detailed summary of the optimization of process parameters and genetic engineering strategies for improving the performance of MFC has been provided. Lastly, the applications of MFC for wastewater treatment, bioelectricity generation, and biosensor development have been reviewed.},
}

@article {pmid39009090,
year = {2024},
author = {Li, X and Xiao, L and Sui, X and Li, M and Wang, N and Sun, Z and Li, T and Cao, X and Li, B},
title = {Municipal solid waste leachate treatment by three-stage membrane aeration biofilm reactor system.},
journal = {Chemosphere},
volume = {},
number = {},
pages = {142847},
doi = {10.1016/j.chemosphere.2024.142847},
pmid = {39009090},
issn = {1879-1298},
abstract = {A combined process of coagulation pretreatment and three-stage membrane aeration biofilm reactor (MABR) system was successfully applied for the first time to treat actual municipal solid waste leachate (MSWL), which was characterized by high concentrations of toxic hard-to-degrade organics and salinity. The results showed that 9.8% - 21.3% of organics could be removed from actual MSWL by coagulation with polymeric aluminum chloride (PAC). Three-stage MABR contributed 95.6% of the chemical oxygen demand (COD) removal, with the influent COD concentration ranging from 6000 to 7000 mg/L. At the same time, the removal efficiencies of total nitrogen (TN) and ammonia (NH4[+]-N) could reach to 84.3% and 79.9% without the addition of external carbon source, respectively. The nitrifying/denitrifying bacteria were enriched in the biofilm including Thiobacillus, Azoarcus and Methyloversatilis, which supported the MABR with high nitrogen removal efficiency and significantly toxic tolerance. Principal component analysis (PCA) and the Pearson correlation coefficients (r) illustrated that aeration pressure is a crucial operational parameter, exhibiting a strong correlation between the MABR performance and microbial communities. This work demonstrates that MABR is an effective and low-energy option for simultaneous removal of carbon and nitrogen in the treatment of MSWL.},
}

@article {pmid39008846,
year = {2024},
author = {Dey, R and Mukherjee, R and Biswas, S and Haldar, J},
title = {Stimuli-Responsive Release-Active Dressing: A Promising Solution for Eradicating Biofilm-Mediated Wound Infections.},
journal = {ACS applied materials & interfaces},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsami.4c09820},
pmid = {39008846},
issn = {1944-8252},
abstract = {Biofilm-mediated wound infections pose a significant challenge due to the limitations of conventional antibiotics, which often exhibit narrow-spectrum activity, fail to eliminate recurrent bacterial contamination, and are unable to penetrate the biofilm matrix. While the search for alternatives has explored the use of metal nanoparticles and synthetic biocides, these solutions often suffer from unintended toxicity to surrounding tissues and lack controlled administration and release. In this study, we engineered a pH-responsive release-active dressing film based on carboxymethyl cellulose, incorporating a synthetic antibacterial molecule (SAM-17). The dressing film exhibited optimal mechanical stability for easy application and demonstrated excellent fluid absorption properties, allowing for prolonged moisturization at the site of injury. The film exhibited pH-dependent release of cargo, with 78% release within 24 h at acidic pH, enabling targeted antibacterial drug delivery within the wound microenvironment. Furthermore, the release-active film effectively eliminated repeated challenges of bacterial contamination. Remarkably, the film demonstrated a minimal toxicity profile in both in vitro and in vivo models. The film eliminated preformed bacterial biofilms, achieving a reduction of 2.5 log against methicillin-resistant Staphylococcus aureus (MRSA) and 4.1 log against vancomycin-resistant S. aureus (VRSA). In a biofilm-mediated MRSA wound infection model, this release-active film eradicated the biofilm-embedded bacteria by over 99%, resulting in accelerated wound healing. These findings highlight the potential of this film as an effective candidate for tackling biofilm-associated wound infections.},
}

@article {pmid39003969,
year = {2024},
author = {Jardak, M and Lami, R and Saadaoui, O and Jlidi, H and Stien, D and Aifa, S and Mnif, S},
title = {Control of Staphylococcus epidermidis biofilm by surfactins of an endophytic bacterium Bacillus sp. 15 F.},
journal = {Enzyme and microbial technology},
volume = {180},
number = {},
pages = {110477},
doi = {10.1016/j.enzmictec.2024.110477},
pmid = {39003969},
issn = {1879-0909},
abstract = {The present paper deals with the preparation and annotation of a surfactin(s) derived from a culture of the endophytic bacterium Bacillus 15 F. The LC-MS analysis of the acetonitrile fraction confirmed the presence of surfactins Leu/Ile7 C15, Leu/Ile7 C14 and Leu/Ile7 C13 with [M+H][+] at m/z 1036.6895, 1022.6741 and 1008.6581, respectively. Various concentrations of the surfactin(s) (hereafter referred to as surfactin-15 F) were used to reduce the adhesion of Staphylococcus epidermidis S61, which served as a model for studying antibiofilm activity on polystyrene surfaces. Incubation of Staphylococcus epidermidis S61 with 62.5 µg/ml of surfactin-15 F resulted in almost complete inhibition of biofilm formation (90.3 ± 3.33 %), and a significant reduction of cell viability (resazurin-based fluorescence was more than 200 times lower). The antiadhesive effect of surfactin-15 F was confirmed by scanning electron microscopy. Surfactin-15 F demonstrated an eradication effect against preformed biofilm, causing severe disruption of Staphylococcus epidermidis S61 biofilm structure and reducing viability. The results suggest that surfactins produced by endophytic bacteria could be an alternative to synthetic products. Surfactin-15 F, used in wound dressings, demonstrated an efficient treatment of the preformed Staphylococcus epidermidis S61 biofilm, and thus having a great potential in medical applications.},
}

@article {pmid39002458,
year = {2024},
author = {Cao, J and Xu, A and Gao, D and Gong, X and Cheng, L and Zhou, Q and Yang, T and Gong, F and Liu, Z and Liang, H},
title = {Enhance PD/A biofilm formation via a novel biochar/tourmaline modified-biocarriers to treat low-strength contaminated surface water: Initial adhesion and high-substrate microenvironment.},
journal = {Journal of environmental management},
volume = {366},
number = {},
pages = {121803},
doi = {10.1016/j.jenvman.2024.121803},
pmid = {39002458},
issn = {1095-8630},
abstract = {In this work, a novel polyurethane carrier modified with biochar and tourmaline/zeolite powder at ratio of 1:1 and 1:2 was developed to promote the formation of biofilms and the synergy of overall bacterial activity for Partial Denitrification/Anammox to treat low-nitrogen contaminated surface water. Based on the batch experiment, the modified biocarrier, BTP2 (biochar: tourmaline = 2: 1), exhibited the highest total nitrogen removal efficiency (83.63%) under influent total nitrogen of 15 mg/L and COD/NO3[-] of 3. The dense biofilm was formed in inner side of biocarrier owing to the increased surface roughness and various functional groups suggested by scanning electron microscopy and Fourier-transform infrared analysis. The EPS content increased from 200.15 to 220.26 mg/g VSS in BTP2 system. Besides, the rapid NH4[+] capture and organics release of the modified carrier fueled the growth of anammox and denitrification bacteria, with the activity of 2.13 ± 0.52 mg N/gVSS/h and 6.70 ± 0.52 mg N/gVSS/h (BTP2). High-throughput sequencing unraveled the increased abundances of Candidatus_Competibacter (0.82%), Thauera (0.60%) and Candidatus_Brocadia (0.55%) which was responsible for the synergy of incomplete reduction of NO3[-] to NO2[-] and NH4[+] oxidation. Overall, this study provided a valid and simple-control guide for biofilm formation towards rapid enrichment and great collaboration of Anammox and denitrification bacteria.},
}

@article {pmid39002428,
year = {2024},
author = {Jyoti, K and Soni, K and Chandra, R},
title = {Pharmaceutical industrial wastewater exhibiting the co-occurrence of biofilm-forming genes in the multidrug-resistant bacterial community poses a novel environmental threat.},
journal = {Aquatic toxicology (Amsterdam, Netherlands)},
volume = {273},
number = {},
pages = {107019},
doi = {10.1016/j.aquatox.2024.107019},
pmid = {39002428},
issn = {1879-1514},
abstract = {The interaction of the environment with the effluent of wastewater treatment plants, having antibiotics, multidrug-resistant (MDR) bacteria, and biofilm-forming genes (BFGs), has vast environmental risks. Antibiotic pollution bottlenecks environmental bacteria and has the potential to significantly lower the biodiversity of environmental bacteria, causing an alteration in ecological equilibrium. It can induce selective pressure for antibiotic resistance (AR) and can transform the non-resistant environmental bacteria into a resistant form through HGT. This study investigated the occurrence of MDR bacteria, showing phenotypic and genotypic characteristics of biofilm. The bacteria were isolated from the pharmaceutical wastewater treatment plants (WWTPs) of Dehradun and Haridwar (India), located in the pharmaceutical areas. The findings of this study demonstrate the coexistence of BFGs and MDR clinical bacteria in the vicinity of pharmaceutical industrial wastewater treatment plants. A total of 47 bacteria were isolated from both WWTPs and tested for antibiotic resistance to 13 different antibiotics; 16 isolates (34.04 %) tested positive for MDR. 5 (31.25 %) of these 16 MDR isolates were producing biofilm and identified as Pseudomonas aeruginosa, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae, and Burkholderia cepacia. The targeted BFGs in this study were ompA, bap and pslA. The most common co-occurring gene was ompA (80 %), with pslA (40 %) being the least common. A. baumannii contains all three targeted genes, whereas B. cepacia only has bap. Except for B. cepacia, all the biofilm-forming MDR isolates show AR to all the tested antibiotics and prove that the biofilm enhances the AR potential. The samples of both wastewater treatment plants also showed the occurrence of tetracycline, ampicillin, erythromycin and chloramphenicol, along with high levels of BOD, COD, PO4[-3], NO3[-], heavy metals and organic pollutants. The co-occurrence of MDR and biofilm-forming tendency in the clinical strain of bacteria and its environmental dissemination may have an array of hazardous impacts on human and environmental health.},
}

@article {pmid39000327,
year = {2024},
author = {Mechmechani, S and Yammine, J and Alhuthali, S and El Mouzawak, M and Charvourou, G and Ghasrsallaoui, A and Chihib, NE and Doulgeraki, A and Karam, L},
title = {Study of the Resistance of Staphylococcus aureus Biofilm, Biofilm-Detached Cells, and Planktonic Cells to Microencapsulated Carvacrol Used Alone or Combined with Low-pH Treatment.},
journal = {International journal of molecular sciences},
volume = {25},
number = {13},
pages = {},
pmid = {39000327},
issn = {1422-0067},
support = {CA18113//EuromicropH COST action/ ; },
mesh = {*Biofilms/drug effects ; *Staphylococcus aureus/drug effects/physiology ; *Cymenes/pharmacology ; Hydrogen-Ion Concentration ; *Microbial Sensitivity Tests ; *Anti-Bacterial Agents/pharmacology ; Plankton/drug effects ; Capsules ; Drug Compounding/methods ; Drug Resistance, Bacterial/drug effects ; },
abstract = {Microbial biofilms pose severe problems in the medical field and food industry, as they are the cause of many serious infections and food-borne diseases. The extreme biofilms' resistance to conventional anti-microbial treatments presents a major challenge to their elimination. In this study, the difference in resistance between Staphylococcus aureus DSMZ 12463 biofilms, biofilm-detached cells, and planktonic cells against microcapsules containing carvacrol was assessed. The antimicrobial/antibiofilm activity of low pH disinfection medium containing the microencapsulated carvacrol was also studied. In addition, the effect of low pH on the in vitro carvacrol release from microcapsules was investigated. The minimum inhibitory concentration of microencapsulated carvacrol was 0.625 mg mL[-1]. The results showed that biofilms exhibited greater resistance to microencapsulated carvacrol than the biofilm-detached cells and planktonic cells. Low pH treatment alone, by hydrochloric acid addition, showed no bactericidal effect on any of the three states of S. aureus strain. However, microencapsulated carvacrol was able to significantly reduce the planktonic cells and biofilm-detached cells below the detection limit (no bacterial counts), and the biofilm by approximatively 3 log CFU mL[-1]. In addition, results showed that microencapsulated carvacrol combined with low pH treatment reduced biofilm by more than 5 log CFU mL[-1]. Thus, the use of microencapsulated carvacrol in acidic environment could be a promising approach to combat biofilms from abiotic surfaces.},
}

*Biofilms/drug effects
*Staphylococcus aureus/drug effects/physiology
*Cymenes/pharmacology
Hydrogen-Ion Concentration
*Microbial Sensitivity Tests
*Anti-Bacterial Agents/pharmacology
Plankton/drug effects
Capsules
Drug Compounding/methods
Drug Resistance, Bacterial/drug effects

@article {pmid38998500,
year = {2024},
author = {Wu, D and Hao, L and Liu, X and Li, X and Zhao, G},
title = {The Anti-Biofilm Properties of Phloretin and Its Analogs against Porphyromonas gingivalis and Its Complex Flora.},
journal = {Foods (Basel, Switzerland)},
volume = {13},
number = {13},
pages = {},
pmid = {38998500},
issn = {2304-8158},
support = {21978101//National Natural Science Foundation of China/ ; 22278159//National Natural Science Foundation of China/ ; },
abstract = {Porphyromonas gingivalis is crucial for the pathogenesis of periodontitis. This research investigated the effects of the fruit-derived flavonoid phloretin and its analogs on the growth of pure P. gingivalis and the flora of P. gingivalis mixed with the symbiotic oral pathogens Fusobacterium nucleatum and Streptococcus mitis. The results showed that the tested flavonoids had little effect on the biofilm amount of pure P. gingivalis, but significantly reduced the biofilm amount of mixed flora to 83.6~89.1%. Biofilm viability decreased to 86.7~92.8% in both the pure- and mixed-bacterial groups after naringenin and phloretin treatments. SEM showed that phloretin and phlorizin displayed a similar and remarkable destructive effect on P. gingivalis and the mixed biofilms. Transcriptome analysis confirmed that biofilm formation was inhibited by these flavonoids, and phloretin significantly regulated the transcription of quorum sensing. Phlorizin and phloretin reduced AI-2 activity to 45.9% and 55.4%, respectively, independent of the regulation of related gene transcription. This research marks the first finding that these flavonoids possess anti-biofilm properties against P. gingivalis and its intricate bacterial community, and the observed performance variations, driven by structural differences, underscore the existence of intriguing structure-activity relationships.},
}

@article {pmid38998429,
year = {2024},
author = {Fernández-Grajera, M and Pacha-Olivenza, MA and Fernández-Calderón, MC and González-Martín, ML and Gallardo-Moreno, AM},
title = {Dynamic Adhesive Behavior and Biofilm Formation of Staphylococcus aureus on Polylactic Acid Surfaces in Diabetic Environments.},
journal = {Materials (Basel, Switzerland)},
volume = {17},
number = {13},
pages = {},
pmid = {38998429},
issn = {1996-1944},
support = {TED2021-131345B-I00//Ministerio de Ciencia, Innovación y Universidades/ ; TED2021-131345B-I00//Fondo Europeo de Desarrollo Regional/ ; PID2022-140422OB-I00//Ministerio de Ciencia, Innovación y Universidades/ ; PID2022-140422OB-I00//Fondo Europeo de Desarrollo Regional/ ; IB20092//Consejería de Educación y Empleo, Junta de Extremadura/ ; Action VI-03//Universidad de Extremadura/ ; },
abstract = {Interest in biodegradable implants has focused attention on the resorbable polymer polylactic acid. However, the risk of these materials promoting infection, especially in patients with existing pathologies, needs to be monitored. The enrichment of a bacterial adhesion medium with compounds that are associated with human pathologies can help in understanding how these components affect the development of infectious processes. Specifically, this work evaluates the influence of glucose and ketone bodies (in a diabetic context) on the adhesion dynamics of S. aureus to the biomaterial polylactic acid, employing different approaches and discussing the results based on the physical properties of the bacterial surface and its metabolic activity. The combination of ketoacidosis and hyperglycemia (GK2) appears to be the worst scenario: this system promotes a state of continuous bacterial colonization over time, suppressing the stationary phase of adhesion and strengthening the attachment of bacteria to the surface. In addition, these supplements cause a significant increase in the metabolic activity of the bacteria. Compared to non-enriched media, biofilm formation doubles under ketoacidosis conditions, while in the planktonic state, it is glucose that triggers metabolic activity, which is practically suppressed when only ketone components are present. Both information must be complementary to understand what can happen in a real system, where planktonic bacteria are the ones that initially colonize a surface, and, subsequently, these attached bacteria end up forming a biofilm. This information highlights the need for good monitoring of diabetic patients, especially if they use an implanted device made of PLA.},
}

@article {pmid38995023,
year = {2024},
author = {Danhorn, T and Hentzer, M and Givskov, M and Parsek, MR and Fuqua, C},
title = {Erratum for Danhorn et al., "Phosphorus Limitation Enhances Biofilm Formation of the Plant Pathogen Agrobacterium tumefaciens through the PhoR-PhoB Regulatory System".},
journal = {Journal of bacteriology},
volume = {},
number = {},
pages = {e0023824},
doi = {10.1128/jb.00238-24},
pmid = {38995023},
issn = {1098-5530},
}

@article {pmid38992841,
year = {2024},
author = {Yui, S and Karia, K and Ali, S},
title = {Evaluation of novel disinfection methods for the remediation of heavily contaminated TMVs and water systems with Pseudomonas aeruginosa biofilm: considerations for new and existing healthcare water systems.},
journal = {The Journal of hospital infection},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.jhin.2024.05.024},
pmid = {38992841},
issn = {1532-2939},
abstract = {BACKGROUND: Pseudomonas aeruginosa is a leading cause of nosocomial Gram-negative bacteraemia. Water systems are a well-documented source of P. aeruginosa and established biofilms are difficult to remove.

AIM: To evaluate the efficacy of regular flushing, peracetic acid disinfection, in-tap thermal disinfection and in-line thermal disinfection to eradicate P. aeruginosa biofilm in a colonised tap model.

METHODS: A simulated tap system was constructed and inoculated with a reference and an environmental strain of P. aeruginosa to form biofilm. Water samples were collected from the taps and P. aeruginosa levels enumerated following disinfection methods. To simulate regular flushing, taps were flushed for 5 minutes, 5 times per day with water tested daily. Peracetic acid (4000 PPM) was manually injected into the system and flushed through the system with a pump. Thermal flushing at 60°C was performed in-line and with an in-tap bypass valve. Tests were conducted with cross-linked polyethylene (PEX) piping and repeated with copper piping.

FINDINGS: Regular flushing and peracetic acid applied with a pump did not reduce P. aeruginosa levels. A limited reduction was observed when manually injecting peracetic acid. In-tap thermal flushing eradicated P. aeruginosa in copper piping but not PEX. In-line thermal flushing was the most effective at reducing P. aeruginosa levels; however, did not eradicate the biofilm.

CONCLUSION: In-line thermal flushing was the most effective method to remove P. aeruginosa biofilm. Results vary significantly with the strain of bacteria and the composition of the plumbing. Several methods used in combination may be necessary to remove established biofilm.},
}

@article {pmid38992475,
year = {2024},
author = {Isolani, R and Pilatti, F and de Paula, MN and Valone, L and da Silva, EL and de Oliveira Caleare, A and Seixas, FAV and Hensel, A and Mello, JCP},
title = {Limonium brasiliense rhizomes extract against virulence factors of Porphyromonas gingivalis: Inhibition of gingipains, bacterial adhesion, and biofilm formation.},
journal = {Fitoterapia},
volume = {177},
number = {},
pages = {106120},
doi = {10.1016/j.fitote.2024.106120},
pmid = {38992475},
issn = {1873-6971},
abstract = {Periodontitis is clinically characterized by destruction of the tooth support system and tooth loss. Porphyromonas gingivalis (Pg) plays a dominant role in periodontitis. Fractions and isolated compounds from an acetone-water extract of the roots of Limonium brasiliense (Lb) were tested in vitro for their anti-adhesive capacity against Pg on human KB buccal cells, influence on gingipains, the main virulence factors of Pg, and biofilm formation. Fractions EAF and FLB7 (50 μg/mL) reduced the bacterial adhesion of Pg to KB cells significantly (63 resp. 70%). The proanthocyanidin samarangenin A inhibited the adhesion (72%, 30 μM), samarangenin B (71%, 20 μM), and the flavan-3-ol epigallocatechin-3-O-gallate (79%, 30 μM). Fraction AQF, representing hydrophilic compounds, reduced the proteolytic activity of Arginin-specific gingipain (IC50 12.78 μg/mL). Fractions EAF and FLB7, characterized by lipohilic constituents, inhibited Arg-gingipain (IC50 3 μg/mL). On Lysine-specific gingipain, AQF has an IC50 15.89, EAF 14.15, and FLB7 6 μg/mL. The reduced bacterial adhesion is due to a strong interaction of proanthocyanidins with gingipains. AQF, EAF, and FLB7 significantly inhibited biofilm formation: IC50 11.34 (AQF), 11.66 (EAF), and 12.09 μg/mL (FLB7). In silico analysis indicated, that the polyphenols act against specific targets of Pg, not affecting mammalian cells. Therefore, Lb might be effective for prevention of periodontal disease by influencing virulence factors of Pg.},
}

@article {pmid38991244,
year = {2024},
author = {Heusser, A and Wackernagel, I and Reinmann, M and Udert, KM},
title = {Increasing urine nitrification performance with sequential membrane aerated biofilm reactors.},
journal = {Water research},
volume = {261},
number = {},
pages = {122019},
doi = {10.1016/j.watres.2024.122019},
pmid = {38991244},
issn = {1879-2448},
abstract = {This study aimed to investigate whether separating organics depletion from nitrification increases the overall performance of urine nitrification. Separate organics depletion was facilitated with membrane aerated biofilm reactors (MABRs). The high pH and ammonia concentration in stored urine inhibited nitrification in the first stage and therewith allowed the separation of organics depletion from nitrification. An organics removal of 70 % was achieved at organic loading rates in the influent of 3.7 gCOD d[-1] m[-2]. Organics depletion in a continuous flow stirred tank reactor (CSTR) for organics depletion led to ammonia stripping through diffused aeration of up to 13 %. Using an MABR, diffusion into the lumen amounted for 4 % ammonia loss only. In the MABR, headspace volume and therefore ammonia loss through the headspace was negligible. By aerating the downstream MABR for nitrification with the off-gas of the MABR for organics depletion, 96 % of the ammonia stripped in the first stage could be recovered in the second stage, so that the overall ammonia loss was negligibly low. Nitrification of the organics-depleted urine was studied in MABRs, CSTRs, and sequencing batch reactors in fed batch mode (FBRs), the latter two operated with suspended biomass. The experiments demonstrated that upstream organics depletion can double the nitrification rate. In a laboratory-scale MABR, nitrification rates were recorded of up to 830 mgNL[-1] d[-1] (3.1 gN m[-2] d[-1]) with ambient air and over 1500 mgNL[-1] d[-1] (6.7 gN m[-2] d[-1]) with oxygen-enriched air. Experiments with a laboratory-scale MABR showed that increasing operational parameters such as pH, recirculation flow, scouring frequency, and oxygen content increased the nitrification rate. The nitrification in the MABR was robust even at high pH setpoints of 6.9 and was robust against process failures arising from operational mistakes. The hydraulic retention time (HRT) required for nitrification was only 1 to 2 days. With the preceding organics depletion, the HRT for our system requires 2 to 3 days in total, whereas a combined activated sludge system requires 4 to 8 days. The N2O concentration in the off-gas increases with increasing nitrification rates; however, the N2O emission factor was 2.8 % on average and independent of nitrification rates. These results indicate that the MABR technology has a high potential for efficient and robust production of ammonium nitrate from source-separated urine.},
}

@article {pmid38991000,
year = {2024},
author = {Arif, M and Asif, A and Nazeer, K and Sultan, S and Riaz, S},
title = {Coexistence of β-lactamase genes and biofilm forming potential among carbapenem-resistant Acinetobacter baumannii in Lahore, Pakistan.},
journal = {Journal of infection in developing countries},
volume = {18},
number = {6},
pages = {943-949},
doi = {10.3855/jidc.19119},
pmid = {38991000},
issn = {1972-2680},
mesh = {*Biofilms/growth & development ; *beta-Lactamases/genetics ; Humans ; Pakistan ; *Acinetobacter baumannii/genetics/drug effects ; Male ; Cross-Sectional Studies ; Adult ; Middle Aged ; Female ; *Acinetobacter Infections/microbiology ; *Anti-Bacterial Agents/pharmacology ; *Carbapenems/pharmacology ; Microbial Sensitivity Tests ; Young Adult ; Bacterial Proteins/genetics ; Adolescent ; },
abstract = {INTRODUCTION: Our goal was to investigate the antimicrobial resistance due to beta-lactamase genes and virulent determinants (biofilm-forming ability) expressed by Acinetobacter collected from health settings in Pakistan. A cross-sectional study was conducted for the molecular characterization of carbapenemases and biofilm-producing strains of Acinetobacter spp.

METHODOLOGY: Two twenty-three imipenem-resistant Acinetobacter isolates were analyzed from 2020 to 2023.The combination disk test and modified hodge test were performed. Biofilm forming ability was determined by polystyrene tube assay. Multiplex polymerase chain reaction (PCR) for virulent and biofilm-forming genes, and 16S rRNA sequencing were performed.

RESULTS: 118 (52.9%) carbapenem-resistant Acinetobacter (CR-AB) were isolated from wounds and pus, 121 (54.2%) from males, and 92 (41.2%) from 26-50-years-olds. More than 80% of strains produced β-lactamases and carbapenemases. Based on the PCR amplification of the ITS gene, 174 (78.0%) CR-AB strains were identified from CR-Acinetobacter non-baumannii (ANB). Most CR-AB were strong and moderate biofilm producers. Genetic analysis revealed the blaOXA-23, blaTEM, blaCTX-M blaNDM-1 and blaVIM were prevalent in CR-AB with frequencies 91 (94.8%), 68 (70.8%), 19 (19.7%), 53 (55.2%), 2 (2.0%) respectively. Among virulence genes, OmpA was dominant in CR-AB isolates from wound (83, 86.4%), csuE 63 (80.7%) from non-wound specimens and significantly correlated with blaNDM and blaOXA genes. Phylogenetic analysis revealed three different clades for strains based on specimens.

CONCLUSIONS: CR-AB was highly prevalent in Pakistan and associated with wound infections. The genes, blaOXA-23, blaTEM, blaCTX-M, and blaNDM-1 were detected in CR-AB. Most CR-AB were strong biofilm producers with virulent genes OmpA and csuE.},
}

*Biofilms/growth & development
*beta-Lactamases/genetics
Humans
Pakistan
*Acinetobacter baumannii/genetics/drug effects
Male
Cross-Sectional Studies
Adult
Middle Aged
Female
*Acinetobacter Infections/microbiology
*Anti-Bacterial Agents/pharmacology
*Carbapenems/pharmacology
Microbial Sensitivity Tests
Young Adult
Bacterial Proteins/genetics
Adolescent

@article {pmid38990088,
year = {2024},
author = {Leistikow, KR and May, DS and Suh, WS and Vargas Asensio, G and Schaenzer, AJ and Currie, CR and Hristova, KR},
title = {Bacillus subtilis-derived peptides disrupt quorum sensing and biofilm assembly in multidrug-resistant Staphylococcus aureus.},
journal = {mSystems},
volume = {},
number = {},
pages = {e0071224},
doi = {10.1128/msystems.00712-24},
pmid = {38990088},
issn = {2379-5077},
abstract = {UNLABELLED: Multidrug-resistant Staphylococcus aureus is one of the most clinically important pathogens in the world, with infections leading to high rates of morbidity and mortality in both humans and animals. The ability of S. aureus to form biofilms protects cells from antibiotics and promotes the transfer of antibiotic resistance genes; therefore, new strategies aimed at inhibiting biofilm growth are urgently needed. Probiotic species, including Bacillus subtilis, are gaining interest as potential therapies against S. aureus for their ability to reduce S. aureus colonization and virulence. Here, we search for strains and microbially derived compounds with strong antibiofilm activity against multidrug-resistant S. aureus by isolating and screening Bacillus strains from a variety of agricultural environments. From a total of 1,123 environmental isolates, we identify a single strain B. subtilis 6D1, with a potent ability to inhibit biofilm growth, disassemble mature biofilm, and improve antibiotic sensitivity of S. aureus biofilms through an Agr quorum sensing interference mechanism. Biochemical and molecular networking analysis of an active organic fraction revealed multiple surfactin isoforms, and an uncharacterized peptide was driving this antibiofilm activity. Compared with commercial high-performance liquid chromatography grade surfactin obtained from B. subtilis, we show these B. subtilis 6D1 peptides are significantly better at inhibiting biofilm formation in all four S. aureus Agr backgrounds and preventing S. aureus-induced cytotoxicity when applied to HT29 human intestinal cells. Our study illustrates the potential of exploring microbial strain diversity to discover novel antibiofilm agents that may help combat multidrug-resistant S. aureus infections and enhance antibiotic efficacy in clinical and veterinary settings.

IMPORTANCE: The formation of biofilms by multidrug-resistant bacterial pathogens, such as Staphylococcus aureus, increases these microorganisms' virulence and decreases the efficacy of common antibiotic regimens. Probiotics possess a variety of strain-specific strategies to reduce biofilm formation in competing organisms; however, the mechanisms and compounds responsible for these phenomena often go uncharacterized. In this study, we identified a mixture of small probiotic-derived peptides capable of Agr quorum sensing interference as one of the mechanisms driving antibiofilm activity against S. aureus. This collection of peptides also improved antibiotic killing and protected human gut epithelial cells from S. aureus-induced toxicity by stimulating an adaptive cytokine response. We conclude that purposeful strain screening and selection efforts can be used to identify unique probiotic strains that possess specially desired mechanisms of action. This information can be used to further improve our understanding of the ways in which probiotic and probiotic-derived compounds can be applied to prevent bacterial infections or improve bacterial sensitivity to antibiotics in clinical and agricultural settings.},
}

@article {pmid38990043,
year = {2024},
author = {Momeni, SS and Cao, X and Xie, B and Rainey, K and Childers, NK and Wu, H},
title = {Intraspecies interactions of Streptococcus mutans impact biofilm architecture and virulence determinants in childhood dental caries.},
journal = {mSphere},
volume = {},
number = {},
pages = {e0077823},
doi = {10.1128/msphere.00778-23},
pmid = {38990043},
issn = {2379-5042},
abstract = {Early childhood dental caries (ECC) is the most common chronic disease among children, especially among low socioeconomic populations. Streptococcus mutans is most frequently associated with initiation of ECC. Although many studies report children with multiple S. mutans strains (i.e., genotypes) have greater odds of developing ECC, studies investigating intraspecies interactions in dental caries are lacking. This study investigates the impact of intraspecies interactions on cariogenic and fitness traits of clinical S. mutans isolates using in vitro and in vivo approaches. Association analysis evaluated if presence of multiple S. mutans genotypes within the first year of colonization was associated with caries. Initially, clinical S. mutans isolates from 10 children were evaluated. S. mutans strains (G09 and G18, most prevalent) isolated from one child were used for subsequent analysis. Biofilm analysis was performed for single and mixed cultures to assess cariogenic traits, including biofilm biomass, intra-polysaccharide, pH, and glucan. Confocal laser scanning microscopy (CLSM) and time-lapse imaging were used to evaluate spatial and temporal biofilm dynamics, respectively. A Drosophila model was used to assess colonization in vivo. Results showed the mean biofilm pH was significantly lower in co-cultured biofilms versus monoculture. Doubling of S. mutans biofilms was observed by CLSM and in vivo colonization in Drosophila for co-cultured S. mutans. Individual strains occupied specific domains in co-culture and G09 contributed most to increased co-culture biofilm thickness and colonization in Drosophila. Biofilm formation and acid production displayed distinct signatures in time-lapsed experiments. This study illuminates that intraspecies interactions of S. mutans significantly impacts biofilm acidity, architecture, and colonization.IMPORTANCEThis study sheds light on the complex dynamics of a key contributor to early childhood dental caries (ECC) by exploring intraspecies interactions of different S. mutans strains and their impact on cariogenic traits. Utilizing clinical isolates from children with ECC, the research highlights significant differences in biofilm architecture and acid production in mixed versus single genotype cultures. The findings reveal that co-cultured S. mutans strains exhibit increased cell density and acidity, with individual strains occupying distinct domains. These insights, enhanced by use of time-lapsed confocal laser scanning microscopy and a Drosophila model, offer a deeper understanding of ECC pathogenesis and potential avenues for targeted interventions.},
}

@article {pmid38989494,
year = {2024},
author = {Datla, VDD and Uppalapati, LV and Pilli, HPK and Mandava, J and Kantheti, S and Komireddy, SNK and Chandolu, V},
title = {Effect of ultrasonic and Er,Cr:YSGG laser-activated irrigation protocol on dual-species root canal biofilm removal: An in vitro study.},
journal = {Journal of conservative dentistry and endodontics},
volume = {27},
number = {6},
pages = {613-620},
pmid = {38989494},
issn = {2950-4708},
abstract = {AIM: The aim of the study was to investigate the disinfecting efficacy of a standardized irrigating solution activated by ultrasonics or laser irradiation on mature dual-species biofilms at different root levels in vitro.

MATERIALS AND METHODS: Conventional access cavity preparations were done on 160 single-rooted mandibular premolar teeth with single canals. Freshly extracted oral microbial strains of Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, and Candida albicans after biochemical confirmation were used to generate two discrete dual-species microbial inoculums. The sterilized tooth samples were randomly segregated into two groups (n = 80) and inoculated with a mixed inoculum of S. aureus + E. faecalis strains (Group 1) and S. mutans + C. albicans strains (Group 2), respectively. Following the 21-day incubation period under aerobic conditions, the infected specimens in each group were divided into four subgroups (n = 20) and subjected to experimental treatment protocols. This included a positive control (no treatment of biofilms), syringe irrigation alone with TruNatomy needle, passive ultrasonically activated irrigation with 20# Irrisafe tip, and laser agitation of irrigant with Er,Cr:YSGG laser using RFT 2 laser tip. Root canals of experimental specimens (except the control samples) are instrumented with TruNatomy rotary file system using 1:1 mixture of 3% NaOCl and 18% etidronic acid as irrigants. The quantitative assessment of reduction in viable biofilm microbes after treatment was done using colony-forming unit counts and confocal laser scanning microscopy image analysis. The obtained data were analyzed statistically with a significant level set at 0.05.

RESULTS: Laser-assisted irrigation has shown a considerably higher mean percentage reduction of microbes compared to ultrasonic agitation and the syringe irrigation showed the least microbial reduction (P = 0.001). No significant difference was noted between the three root regions of ultrasonic and laser groups (P > 0.05), whereas in the syringe groups, apical portions showed higher microbial counts compared to cervical and mid-root regions (P = 0.001).

CONCLUSION: Erbium laser-assisted irrigation has performed superior to ultrasonic agitation against both the experimental dual-species biofilms, while the syringe irrigation showed the least microbial reduction specifically at apical root portions.},
}

@article {pmid38988529,
year = {2024},
author = {Wang, D and Zeng, N and Li, C and Li, Z and Zhang, N and Li, B},
title = {Fungal biofilm formation and its regulatory mechanism.},
journal = {Heliyon},
volume = {10},
number = {12},
pages = {e32766},
pmid = {38988529},
issn = {2405-8440},
abstract = {Fungal biofilm is a microbial community composed of fungal cells and extracellular polymeric substances (EPS). In recent years, fungal biofilms have played an increasingly important role in many fields. However, there are few studies on fungal biofilms and their related applications and development are still far from enough. Therefore, this review summarizes the composition and function of EPS in fungal biofilms, and improves and refines the formation process of fungal biofilms according to the latest viewpoints. Moreover, based on the study of Saccharomyces cerevisiae and Candida albicans, this review summarizes the gene regulation network of fungal biofilm synthesis, which is crucial for systematically understanding the molecular mechanism of fungal biofilm formation. It is of great significance to further develop effective methods at the molecular level to control harmful biofilms or enhance and regulate the formation of beneficial biofilms. Finally, the quorum sensing factors and mixed biofilms formed by fungi in the current research of fungal biofilms are summarized. These results will help to deepen the understanding of the formation process and internal regulation mechanism of fungal biofilm, provide reference for the study of EPS composition and structure, formation, regulation, group behavior and mixed biofilm formation of other fungal biofilms, and provide strategies and theoretical basis for the control, development and utilization of fungal biofilms.},
}

@article {pmid38988475,
year = {2024},
author = {Khadraoui, N and Essid, R and Damergi, B and Fares, N and Gharbi, D and Forero, AM and Rodríguez, J and Abid, G and Kerekes, EB and Limam, F and Jiménez, C and Tabbene, O},
title = {Myrtus communis leaf compounds as novel inhibitors of quorum sensing-regulated virulence factors and biofilm formation: In vitro and in silico investigations.},
journal = {Biofilm},
volume = {8},
number = {},
pages = {100205},
pmid = {38988475},
issn = {2590-2075},
abstract = {Antibiotic resistance of the Gram-negative bacterium Pseudomonas aeruginosa and its ability to form biofilm through the Quorum Sensing (QS) mechanism are important challenges in the control of infections caused by this pathogen. The extract of Myrtus communis (myrtle) showed strong anti-QS effect on C hromobacterium . violaceum 6267 by inhibiting 80 % of the production of violacein pigment at a sub-MIC concentration of 1/8 (31.25 μg/mL). In addition, the extract exhibited an inhibitory effect on virulence factors of P. aeruginosa PAO1 at half MIC (125 μg/mL), significantly reducing the formation of biofilms (72.02 %), the swarming activity (75 %), and the production of protease (61.83 %) and pyocyanin (97 %). The active fraction also downregulated the expression of selected regulatory genes involved in the biofilm formation and QS in the P. aeruginosa PAO1 strain. These genes included the autoinducer synthase genes (lasI and rhlI), the genes involved in the expression of their corresponding receptors (lasR and rhlR), and the pqsA genes. The analysis of the active fraction by HPLC/UV/MS and NMR allowed the identification of three phenolic compounds, 3,5-di-O-galloylquinic acid, myricetin 3-O-α-l-rhamnopyranoside (myricitrin), and myricetin 3-O-(2″-O-galloyl)-ß-d-galactopyranoside. In silico studies showed that 3,5-di-O-galloylquinic acid, with an affinity score of -9.20 kcal/mol, had the highest affinity to the active site of the CviR protein (3QP8), a QS receptor from C. violaceum. Additionally, myricetin 3-O-α-l-rhamnopyranoside (myricitrin) and myricetin 3-O-(2″-O-galloyl)-ß-d-galactopyranoside interact to a lesser extent with 3QP8. In conclusion, this study contributed significantly to the discovery of new QS inhibitors from M. communis leaves against resistant Gram-negative pathogens.},
}

@article {pmid38988413,
year = {2024},
author = {Dietl, S and Merkl, P and Sotiriou, GA},
title = {Prevention of uropathogenic E. coli biofilm formation by hydrophobic nanoparticle coatings on polymeric substrates.},
journal = {RSC applied interfaces},
volume = {1},
number = {4},
pages = {667-670},
pmid = {38988413},
issn = {2755-3701},
abstract = {Biofilms in infections are a major health-care challenge and strategies to reduce their formation on medical devices are crucial. Fabrication of superhydrophobic coatings based on hydrocarbon adsorption on rare-earth oxides constitutes an attractive strategy, but their capacity to prevent biofilm formation has not been studied. Here, we explore a scalable and reproducible nanofabrication process for the manufacture of such superhydrophobic coatings and study their antibiofilm activity against clinically-relevant uropathogenic E. coli. These coatings reduce bacterial biofilm formation and prevent biofouling with potential applications preventing medical device related infections.},
}

@article {pmid38986879,
year = {2024},
author = {Han, NN and Yang, JH and Fan, NS and Jin, RC},
title = {Mechanistic insight into microbial interaction and metabolic pattern of anammox consortia on surface-modified biofilm carrier with extracellular polymeric substances.},
journal = {Bioresource technology},
volume = {407},
number = {},
pages = {131092},
doi = {10.1016/j.biortech.2024.131092},
pmid = {38986879},
issn = {1873-2976},
abstract = {The extremely slow growth rate of anaerobic ammonia oxidation (anammox) bacteria limits full-scale application of anammox process worldwide. In this study, extracellular polymeric substances (EPS)-coated polypropylene (PP) carriers were prepared for biofilm formation. The biomass adhesion rate of EPS-PP carrier was 12 times that of PP carrier, and EPS-PP achieved significant enrichment of E. coli BY63. The 120-day continuous flow experiment showed that the EPS-PP carrier accelerated the formation of anammox biofilm, and the nitrogen removal efficiency increased by 10.5 %. In addition, the abundance of Candidatus Kuenenia in EPS-PP biofilm was 27.1%. Simultaneously, amino acids with high synthesis cost and the metabolites of glycerophospholipids related to biofilm formation on EPS-PP biofilm were significantly up-regulated. Therefore, EPS-PP carriers facilitated the rapid formation of anammox biofilm and promoted the metabolic activity of functional bacteria, which further contributed to the environmental and economic sustainability of anammox process.},
}

@article {pmid38986504,
year = {2024},
author = {Martin, JD and Tisler, S and Scheel, M and Svendsen, S and Anwar, MZ and Zervas, A and Ekelund, F and Bester, K and Hansen, LH and Jacobsen, CS and Ellegaard-Jensen, L},
title = {Total RNA analysis of the active microbiome on moving bed biofilm reactor carriers under incrementally increasing micropollutant concentrations.},
journal = {FEMS microbiology ecology},
volume = {},
number = {},
pages = {},
doi = {10.1093/femsec/fiae098},
pmid = {38986504},
issn = {1574-6941},
abstract = {Micropollutants are increasingly prevalent in the aquatic environment. A major part of these originates from wastewater treatment plants since traditional treatment technologies do not remove micropollutants sufficiently. Moving bed biofilm reactors (MBBRs), however, have been shown to aid in micropollutant removal when applied to conventional wastewater treatment as a polishing step. Here, we used Total RNA sequencing to investigate both the active microbial community and functional dynamics of MBBR biofilms when these were exposed to increasing micropollutant concentrations over time. Concurrently, we conducted batch culture experiments using biofilm carriers from the MBBRs to assess micropollutant degradation potential. Our study showed that biofilm eukaryotes, in particular protozoa, were negatively influenced by micropollutant exposure, in contrast to prokaryotes that increased in relative abundance. Further, we found several functional genes that were differentially expressed between the MBBR with added micropollutants and the control. These include genes involved in aromatic and xenobiotic compound degradation. Moreover, the biofilm carrier batch experiment showed vastly different alterations in benzotriazole and diclofenac degradation following the increased micropollutant concentrations in the MBBR. Ultimately, this study provides essential insights into the microbial community and functional dynamics of MBBRs and how an increased load of micropollutants influences these dynamics.},
}

@article {pmid38984682,
year = {2024},
author = {Fruleux, T and Sauleau, P and Caudal, F and Champion, M and Chauvin, L and Castro, M and Le Duigou, A},
title = {Marine biofilm formation on flax fibre reinforced biocomposites.},
journal = {Biofouling},
volume = {},
number = {},
pages = {1-16},
doi = {10.1080/08927014.2024.2373870},
pmid = {38984682},
issn = {1029-2454},
abstract = {Artificial reefs represent useful tools to revitalize coastal and ocean ecosystems. Their formulation determines the biofilm formation which is the prerequisite for the colonization process by marine micro- and macroorganisms. In comparison with concrete, biobased polymers offer improved characteristics, including architecture, formulation, rugosity and recycling. This article aims to explore a new scale of artificial reef made of biocomposites reinforced with a high flax fibre (Linum utilatissimum) content (30%). Cellular adhesion and resulting biofilm formation were assessed using two marine microorganisms: Pseudoalteromonas sp. 3J6 and Cylindrotheca closterium. The influence of flax fibre leachates and plastic monomers on the growth of those marine microorganisms were also evaluated. Results indicated that the introduction of flax fibres inside the polymer matrix modified its physicochemical properties thus modulating adhesion and biofilm formation depending on the microorganism. This study gives insights for further developments of novel functionalized artificial reefs made of biocomposites.},
}

@article {pmid38982956,
year = {2024},
author = {Ramaiah, KB and Suresh, I and Srinandan, CS and Sai Subramanian, N and Rayappan, JBB},
title = {A dual-sensing strategy for the early diagnosis of urinary tract infections via detecting biofilm cellulose using aromatic amino acid-capped Au and Ag nanoparticles.},
journal = {Journal of materials chemistry. B},
volume = {},
number = {},
pages = {},
doi = {10.1039/d4tb00902a},
pmid = {38982956},
issn = {2050-7518},
abstract = {Currently, urinary tract infection (UTI) diagnosis focuses on planktonic cell detection rather than biofilm detection, but the facile identification of UPEC bacterial biofilms is crucial in UTI diagnosis as the biofilm formed by bacteria is the causative agent of recurrent and chronic UTIs. Therefore, in this work, we developed a simple, cost-effective, colorimetric, and electrochemical-based strategy for the detection of cellulose in urine. Cellulose, a biofilm matrix component, was detected using tyrosine-capped gold and silver nanoparticles through a visible colorimetric change with a decrease in the absorbance intensity and a decrease in current response in the case of cyclic voltammetry. The sensor displayed a linear detection range of 10-70 mg mL[-1] for colorimetry and 10-300 μg mL[-1] for cyclic voltammetry with a good selectivity of <2.8% and a recovery rate of 95-100% in real-time sample analysis. Moreover, the binding affinity of cellulose with tyrosine was investigated using molecular docking studies to validate the sensing mechanism. We anticipate that our work will aid clinicians in the implementation of rapid, cost-effective, and definitive diagnosis of UTIs.},
}

@article {pmid38980701,
year = {2024},
author = {Yazdani-Ahmadabadi, H and Yu, K and Gonzalez, K and Luo, HD and Lange, D and Kizhakkedathu, JN},
title = {Long-Term Prevention of Biofilm Formation by Polycatechol-Based Supramolecular Assemblies with Low Molecular Weight Polymers on Surfaces.},
journal = {ACS applied materials & interfaces},
volume = {},
number = {},
pages = {},
doi = {10.1021/acsami.4c02371},
pmid = {38980701},
issn = {1944-8252},
abstract = {Achievement of a stable surface coating with long-term resistance to biofilm formation remains a challenge. Catechol-based polymerization chemistry and surface deposition are used as tools for surface modification of diverse materials. However, the control of surface deposition of the coating, surface coverage, coating properties, and long-term protection against biofilm formation remain to be solved. We report a new approach based on supramolecular assembly to generate long-acting antibiofilm coating. Here, we utilized catechol chemistry in combination with low molecular weight amphiphilic polymers for the generation of such coatings. Screening studies with diverse low molecular weight (LMW) polymers and different catechols are utilized to identify lead compositions, which resulted in a thick coating with high surface coverage, smoothness, and antibiofilm activity. We have identified that small supramolecular assemblies (∼10 nm) formed from a combination of polydopamine and LMW poly(N-vinyl caprolactam) (PVCL) resulted in relatively thick coating (∼300 nm) with excellent surface coverage in comparison to other polymers and catechol combinations. The coating properties, such as thickness (10-300 nm) and surface hydrophilicity (with water contact angle: 20-60°), are readily controlled. The optimal coating composition showed excellent antibiofilm properties with long-term (>28 days) antibiofilm activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) strains. We further utilized the combination of optimal binary coating with silver to generate a coating with sustained release of silver ions, resulting in killing both adhered and planktonic bacteria and preventing long-term surface bacterial colonization. The new coating method utilizing LMW polymers opens a new avenue for the development of a novel class of thick, long-acting antibiofilm coatings.},
}

@article {pmid38979200,
year = {2024},
author = {Korshoj, LE and Kielian, T},
title = {Bacterial single-cell RNA sequencing captures biofilm transcriptional heterogeneity and differential responses to immune pressure.},
journal = {bioRxiv : the preprint server for biology},
volume = {},
number = {},
pages = {},
doi = {10.1101/2024.06.28.601229},
pmid = {38979200},
issn = {2692-8205},
abstract = {Biofilm formation is an important mechanism of survival and persistence for many bacterial pathogens. These multicellular communities contain subpopulations of cells that display vast metabolic and transcriptional diversity along with high recalcitrance to antibiotics and host immune defenses. Investigating the complex heterogeneity within biofilm has been hindered by the lack of a sensitive and high-throughput method to assess stochastic transcriptional activity and regulation between bacterial subpopulations, which requires single-cell resolution. We have developed an optimized bacterial single-cell RNA sequencing method, BaSSSh-seq, to study Staphylococcus aureus diversity during biofilm growth and transcriptional adaptations following immune cell exposure. We validated the ability of BaSSSh-seq to capture extensive transcriptional heterogeneity during biofilm compared to planktonic growth. Application of new computational tools revealed transcriptional regulatory networks across the heterogeneous biofilm subpopulations and identification of gene sets that were associated with a trajectory from planktonic to biofilm growth. BaSSSh-seq also detected alterations in biofilm metabolism, stress response, and virulence that were tailored to distinct immune cell populations. This work provides an innovative platform to explore biofilm dynamics at single-cell resolution, unlocking the potential for identifying biofilm adaptations to environmental signals and immune pressure.},
}

@article {pmid38977975,
year = {2024},
author = {Alabdullatif, M},
title = {Evaluating the effects of temperature and agitation on biofilm formation of bacterial pathogens isolated from raw cow milk.},
journal = {BMC microbiology},
volume = {24},
number = {1},
pages = {251},
pmid = {38977975},
issn = {1471-2180},
mesh = {Animals ; *Biofilms/growth & development ; *Milk/microbiology ; *Temperature ; Cattle ; *Bacteria/isolation & purification/classification/growth & development ; Saudi Arabia ; Food Microbiology ; Bacterial Physiological Phenomena ; },
abstract = {OBJECTIVES: To study the effect of agitation and temperature on biofilm formation (cell aggregates embedded within a self-produced matrix) by pathogenic bacteria isolated from Raw cow milk (RCM).

METHODS: A 40 RCM samples were gathered from eight dairy farms in Riyadh, Saudi Arabia. After bacterial culturing and isolation, gram staining was performed, and all pathogenic, identified using standard criteria established by Food Standards Australia New Zealand (FSANZ), and non-pathogenic bacteria were identified using VITEK-2 and biochemical assays. To evaluate the effects of temperature and agitation on biofilm formation, isolated pathogenic bacteria were incubated for 24 h under the following conditions: 4 °C with no agitation (0 rpm), 15 °C with no agitation, 30 °C with no agitation, 30 °C with 60 rpm agitation, and 30 °C with 120 rpm agitation. Then, biofilms were measured using a crystal violet assay.

RESULTS: Of the eight farm sites, three exhibited non-pathogenic bacterial contamination in their raw milk samples. Of the total of 40 raw milk samples, 15/40 (37.5%; from five farms) were contaminated with pathogenic bacteria. Overall, 346 bacteria were isolated from the 40 samples, with 329/346 (95.1%) considered as non-pathogenic and 17/346 (4.9%) as pathogenic. Most of the isolated pathogenic bacteria exhibited a significant (p < 0.01) increase in biofilm formation when grown at 30 °C compared to 4 °C and when grown with 120 rpm agitation compared to 0 rpm.

CONCLUSION: Herein, we highlight the practices of consumers in terms of transporting and storing (temperature and agitation) can significantly impact on the growth of pathogens and biofilm formation in RCM.},
}

Animals
*Biofilms/growth & development
*Milk/microbiology
*Temperature
Cattle
*Bacteria/isolation & purification/classification/growth & development
Saudi Arabia
Food Microbiology
Bacterial Physiological Phenomena

@article {pmid38977038,
year = {2024},
author = {Kumar Jaiswal, V and Dutta Gupta, A and Sonwani, RK and Shekher Giri, B and Sharan Singh, R},
title = {Enhanced biodegradation of 2, 4-dichlorophenol in packed bed biofilm reactor by impregnation of polyurethane foam with Fe3O4 nanoparticles: Bio-kinetics, process optimization, performance evaluation and toxicity assessment.},
journal = {Bioresource technology},
volume = {406},
number = {},
pages = {131085},
doi = {10.1016/j.biortech.2024.131085},
pmid = {38977038},
issn = {1873-2976},
abstract = {In this work, an effort has been made to enhance the efficacy of biological process for the effective degradation of 2, 4-dichlorophenol (2, 4-DCP) from wastewater. The polyurethane foam was modified with Fe3O4 nanoparticles and combined with polyvinyl alcohol, sodium alginate, and bacterial consortium for biodegradation of 2, 4-DCP in a packed bed biofilm reactor. The maximum removal efficiency of 2, 4-DCP chemical oxygen demand, and total organic carbon were found to be 92.51 ± 0.83 %, 86.85 ± 1.32, and 91.78 ± 1.24 %, respectively, in 4 days and 100 mg L[-1] of 2, 4-DCP concentration at an influent loading rate of 2 mg L[-1]h[-1] and hydraulic retention time of 50 h. Packed bed biofilm reactor was effective for up to four cycles to remove 2, 4-DCP. Growth inhibition kinetics were evaluated using the Edward model, yielding maximum growth rate of 0.45 day[-1], inhibition constant of 110.6 mg L[-1], and saturation constant of 62.3 mg L[-1].},
}

@article {pmid38975180,
year = {2024},
author = {Jonblat, S and As-Sadi, F and El Khoury, A and Badr, N and Kallassy, M and Chokr, A},
title = {Determining the dispersion time in Staphylococcus epidermidis biofilm using physical and molecular approaches.},
journal = {Heliyon},
volume = {10},
number = {12},
pages = {e32389},
pmid = {38975180},
issn = {2405-8440},
abstract = {Despite being an innocuous commensal of human skin and mucous membranes, Staphylococcus epidermidis, infects surgical wounds and causes infections through biofilm formation. This study evaluates, in a time-dependent experiment, the self-dispersion of S. epidermidis CIP 444 biofilm when formed on borosilicate glass (hydrophilic) and polystyrene (hydrophobic) surfaces, using physical and molecular approaches. During a seven-day period of incubation, absorbance measurement revealed a drop in biofilm optical density on both studied surfaces on day 4 (0.043-0.035 nm/cm[2], polystyrene), (0.06-0.053 nm/cm[2], borosilicate glass). Absorbance results were correlated with crystal violet staining that showed a clear detachment from day 4. The blue color increases again on day 7, with an increase in biofilm optical density indicating the regeneration of the biofilm. Changes in gene expression in the S. epidermidis biofilm were assessed using a real-time reverse transcription-polymerase chain reaction. High expression of agr genes was detected on days 4 and 5, confirming our supposition of dispersion in this period, autolysin genes like atlE1 and aae were upregulated from day 3 until day 6 and the genes responsible for slime production and biofilm accumulation, were upregulated on days 4, 5, and 6 (ica ADBC) and on days 5, 6 and 7 (aap), indicating a dual process taking place. These findings suggest that S. epidermidis CIP 444 biofilms disperse at day 4 and reform at day 7. Over the course of the seven-day investigation, 2[-ΔΔCt] results showed that some genes in the biofilm were dramatically enhanced while others were significantly decreased as compared to planktonic ones.},
}

@article {pmid38974467,
year = {2024},
author = {Myers, C and Atkins, GR and Villarreal, J and Sutton, RB and Cornwall, GA},
title = {The mouse epididymal amyloid matrix is a mammalian counterpart of a bacterial biofilm.},
journal = {iScience},
volume = {27},
number = {6},
pages = {110152},
pmid = {38974467},
issn = {2589-0042},
abstract = {The mouse epididymis is a long tubule connecting the testis to the vas deferens. Its primary functions are to mature spermatozoa into motile and fertile cells and to protect them from pathogens that ascend the male tract. We previously demonstrated that a functional extracellular amyloid matrix surrounds spermatozoa in the epididymal lumen and has host defense functions, properties not unlike that of an extracellular biofilm that encloses and protects a bacterial community. Here we show the epididymal amyloid matrix also structurally resembles a biofilm by containing eDNA, eRNA, and mucin-like polysaccharides. Further these structural components exhibit comparable behaviors and perform functions such as their counterparts in bacterial biofilms. Our studies suggest that nature has used the ancient building blocks of bacterial biofilms to form an analogous structure that nurtures and protects the mammalian male germline.},
}

@article {pmid38974376,
year = {2024},
author = {Hu, Z and Yin, X and Fan, G and Liao, X},
title = {Global Trends in Orthopedic Biofilm Research: A Bibliometric Analysis of 1994-2022.},
journal = {Journal of multidisciplinary healthcare},
volume = {17},
number = {},
pages = {3057-3069},
pmid = {38974376},
issn = {1178-2390},
abstract = {OBJECTIVE: Bibliometric analysis is commonly used to visualize the knowledge foundation, trends, and patterns in a specific scientific field by performing a quantitative evaluation of the relevant literature. The purpose of this study was to perform a bibliometric analysis of recent studies in the field of orthopedic biofilm research and identify its current trends and hotspots.

METHODS: Research studies were retrieved from the Web of Science Core Collection and Scopus databases and analyzed in bibliometrix with R package (4.2.2).

RESULTS: A total of 2426 literature were included in the study. Journal of orthopaedic research and Clinical orthopaedics and related research ranked first in terms of productivity and impact, with 57 published articles and 32 h-index, respectively. Trampuz A, Ohio State Univ and the United States ranked as the most productive authors, institutions, and countries. Biofilm formation, role of sonication, biomaterial mechanism and antibiotic loading have been investigated as the trend and hotspots in the field of orthopedic biofilm research.

CONCLUSION: This study provides a thorough overview of the state of the art of current orthopedic biofilm research and offers valuable insights into recent trends and hotspots in this field.},
}

@article {pmid38973924,
year = {2024},
author = {Sedighi, O and Bednarke, B and Sherriff, H and Doiron, AL},
title = {Nanoparticle-Based Strategies for Managing Biofilm Infections in Wounds: A Comprehensive Review.},
journal = {ACS omega},
volume = {9},
number = {26},
pages = {27853-27871},
pmid = {38973924},
issn = {2470-1343},
abstract = {Chronic wounds containing opportunistic bacterial pathogens are a growing problem, as they are the primary cause of morbidity and mortality in developing and developed nations. Bacteria can adhere to almost every surface, forming architecturally complex communities called biofilms that are tolerant to an individual's immune response and traditional treatments. Wound dressings are a primary source and potential treatment avenue for biofilm infections, and research has recently focused on using nanoparticles with antimicrobial activity for infection control. This Review categorizes nanoparticle-based approaches into four main types, each leveraging unique mechanisms against biofilms. Metallic nanoparticles, such as silver and copper, show promising data due to their ability to disrupt bacterial cell membranes and induce oxidative stress, although their effectiveness can vary based on particle size and composition. Phototherapy-based nanoparticles, utilizing either photodynamic or photothermal therapy, offer targeted microbial destruction by generating reactive oxygen species or localized heat, respectively. However, their efficacy depends on the presence of light and oxygen, potentially limiting their use in deeper or more shielded biofilms. Nanoparticles designed to disrupt extracellular polymeric substances directly target the biofilm structure, enhancing the penetration and efficacy of antimicrobial agents. Lastly, nanoparticles that induce biofilm dispersion represent a novel strategy, aiming to weaken the biofilm's defense and restore susceptibility to antimicrobials. While each method has its advantages, the selection of an appropriate nanoparticle-based treatment depends on the specific requirements of the wound environment and the type of biofilm involved. The integration of these nanoparticles into wound dressings not only promises enhanced treatment outcomes but also offers a reduction in the overall use of antibiotics, aligning with the urgent need for innovative solutions in the fight against antibiotic-tolerant infections. The overarching objective of employing these diverse nanoparticle strategies is to replace antibiotics or substantially reduce their required dosages, providing promising avenues for biofilm infection management.},
}

@article {pmid38973863,
year = {2024},
author = {Wong, MY and Lin, BS and Hu, PS and Huang, TY and Huang, YK},
title = {Nanoparticles of Cs0.33WO3 as Antibiofilm Agents and Photothermal Treatment to Inhibit Biofilm Formation.},
journal = {ACS omega},
volume = {9},
number = {26},
pages = {28144-28154},
pmid = {38973863},
issn = {2470-1343},
abstract = {Metal oxide nanoparticles with photothermal properties have attracted considerable research attention for their use in biomedical applications. Cesium tungsten oxide (Cs0.33WO3) nanoparticles (NPs) exhibit strong absorption in the NIR region due to localized surface plasmon resonance, through which they convert light to heat; hence, they can be applied to photothermal treatment for bacteria and biofilm ablation. Herein, Cs0.33WO3 NPs were synthesized through solid-phase synthesis, and their physical properties were characterized through Zetasizer, energy dispersive X-ray spectroscopy, Fourier transform infrared spectrometer, and scanning and transmission electron microscopy (SEM and TEM, respectively). Burkholderia cenocepacia isolates were cultured in tryptic soy broth supplemented with glucose, and the biofilm inhibition and antibiofilm effects of the NPs were determined using a crystal violet assay and the Cell Counting Kit-8 (CCK-8) assay. The biofilm morphology and viability of NP-treated cultures after NIR irradiation were evaluated through SEM and confocal microscopy, respectively. The cytotoxicity of NPs to human macrophages was also assessed using the CCK-8 assay. The NPs effectively inhibited biofilm formation, with a formation rate of <10% and a viability rate of <50% at the concentration of ≥200 μg/mL. The confocal analysis revealed that NIR irradiation markedly enhanced biofilm cytotoxicity after treatment with the NPs. The assay of cytotoxicity to human macrophages demonstrated the biocompatibility of the NPs and NIR irradiation. In sum, the Cs0.33WO3 NPs displayed effective biofilm inhibition and antibiofilm activity at 200 μg/mL treatment concentration; they exhibited an enhancement effect under the NIR irradiation, suggesting Cs0.33WO3 NPs are a potential candidate agent for NIR-irradiated photothermal treatment in bacterial biofilm inhibition and antibiofilm.},
}

@article {pmid38973737,
year = {2024},
author = {Ji, Y and Hao, J and Tao, X and Li, Z and Chen, L and Qu, N},
title = {Preparation and anti-tumor activity of paclitaxel silk protein nanoparticles encapsulated by biofilm.},
journal = {Pharmaceutical development and technology},
volume = {},
number = {},
pages = {1-29},
doi = {10.1080/10837450.2024.2376075},
pmid = {38973737},
issn = {1097-9867},
abstract = {To address the disadvantages of poor water solubility, cardiotoxicity, and hypersensitivity reactions of paclitaxel (PTX). In this study, paclitaxel silk fibroin nanoparticles (PTX-SF-NPs) were prepared by self-assembly method, and then, the nanoparticles were encapsulated by using the outer membrane vesicles of Escherichia coli (E. coil), so that biofilm-encapsulated paclitaxel silk fibroin nanoparticles (OMV-PTX-SF-NPs) were constructed. Subsequently, the prepared nanoparticles were characterized in terms of particle size and zeta potential, and in vitro cytotoxicity studies were carried out, which showed that both PTX-SF-NPs and OMV-PTX-SF-NPs possessed good antitumor activity against tumor cells. In the in vivo biodistribution study and antitumor study, the results showed that OMV-PTX-SF-NPs could effectively increase the bioavailability of paclitaxel, prolong the action time of paclitaxel in vivo, reduce the absorption of paclitaxel in the stomach, increase the concentration of paclitaxel in tumor tissues, and significantly inhibit the growth of tumors. Overall, OMV-PTX-SF-NPs is a stable extended-release oral formulation of paclitaxel, which can effectively improve the bioavailability of paclitaxel, enhance the anti-tumor activity and reduce the adverse reactions.},
}

@article {pmid38972505,
year = {2024},
author = {Ohara, K and Tomiyama, K and Okuda, T and Tsutsumi, K and Ishihara, C and Hashimoto, D and Fujii, Y and Chikazawa, T and Kurita, K and Mukai, Y},
title = {Dipotassium glycyrrhizate prevents oral dysbiosis caused by Porphyromonas gingivalis in an in vitro saliva-derived polymicrobial biofilm model.},
journal = {Journal of oral biosciences},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.job.2024.07.001},
pmid = {38972505},
issn = {1880-3865},
abstract = {OBJECTIVES: Oral microbiome dysbiosis prevention is important to avoid the onset and progression of periodontal disease. Dipotassium glycyrrhizate (GK2) is a licorice root extract with anti-inflammatory effects, and its associated mechanisms have been well-reported. However, their effects on the oral microbiome have not been investigated. This study aimed to elucidate the effects of GK2 on the oral microbiome using an in vitro polymicrobial biofilm model.

METHODS: An in vitro saliva-derived polymicrobial biofilm model was used to evaluate the effects of GK2 on the oral microbiome. One-week anaerobic culture was performed, in which GK2 was added to the medium. Subsequently, microbiome analysis was performed based on the V1-V2 region of the 16S rRNA gene, and pathogenicity indices were assessed. We investigated the effects of GK2 on various bacterial monocultures by evaluating its inhibitory effects on cell growth, based on culture turbidity.

RESULTS: GK2 treatment altered the microbiome structure and decreased the relative abundance of periodontal pathogenic bacteria, including Porphyromonas. Moreover, GK2 treatment reduced the DPP4 activity -a pathogenicity index of periodontal disease. Specifically, GK2 exhibited selective antibacterial activity against periodontal pathogenic bacteria.

CONCLUSIONS: These findings suggest that GK2 has a selective antibacterial effect against periodontal pathogenic bacteria; thus, preventing oral microbiome dysbiosis. Therefore, GK2 is expected to contribute to periodontal disease prevention by modulating the oral microbiome toward a state with low inflammatory potential, thereby utilizing its anti-inflammatory properties on the host.},
}

@article {pmid38972366,
year = {2024},
author = {Chaves, AC and Boa Ventura, PV and Pereira, MS and da Silva, BF and de Carvalho, FJN and Costa, RA and Lima, BP and Maciel, WC and Carneiro, VA},
title = {Preliminary snapshot reveals a relationship between multidrug-resistance and biofilm production among enterobacteriaceae isolated from fecal samples of farm-raised poultry in ceará, Brazil.},
journal = {Microbial pathogenesis},
volume = {193},
number = {},
pages = {106778},
doi = {10.1016/j.micpath.2024.106778},
pmid = {38972366},
issn = {1096-1208},
abstract = {Antimicrobial resistance and biofilm formation by microbial pathogens pose a significant challenge to poultry production systems due to the persistent risk of dissemination and compromise of bird health and productivity. In this context, the study aimed to investigate the occurrence of different multiresistance phenotypes and the biofilm-forming ability of Enterobacteriaceae isolated from broiler chicken excreta in poultry production units in Ceará, Brazil. Samples were collected from three distinct broiler breeding facilities and subjected to isolation, identification, antibiotic susceptibility testing, phenotypic screening for β-lactamases enzymes, and biofilm formation evaluation. Seventy-one strains were identified, being Escherichia coli (37 %) and Proteus mirabilis (32 %), followed by Klebsiella pneumoniae (11 %), Providencia stuartii (9 %), Klebsiella aerogenes (6 %), Alcaligenes faecalis (4 %), and Salmonella sp. (1 %). A significant proportion (87 %) of multiresistant strains were detected. For the phenotypic evaluation of β-lactamases production, strains with resistance to second and third-generation cephalosporins and carbapenems were tested. About 4 of 6 and 10 of 26 were positive for inducible chromosomal AmpC β-lactamase and extended-spectrum β-lactamase (ESBL), respectively. Regarding biofilm formation, it was observed that all MDR strains were capable of forming biofilm. In this sense. the potential of these MDR bacteria to develop biofilms becomes a significant concern, representing a real threat to both human and animal health, as biofilms offer stability, antimicrobial protection, and facilitate genetic transfer.},
}

@article {pmid38972365,
year = {2024},
author = {Devi B, A and Kv, L and Sugumar, S},
title = {Isolation and Characterization of Bacteriophages against E.coli Urinary Tract Infection and Evaluating their Anti-biofilm Activity and Antibiotic Synergy.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {106789},
doi = {10.1016/j.micpath.2024.106789},
pmid = {38972365},
issn = {1096-1208},
abstract = {Urinary tract infections (UTIs) by Uropathogenic Escherichia coli (UPEC) are a significant health concern, especially due to the increasing prevalence of antibiotic resistance. This study focuses on isolating and characterizing bacteriophages specific to UPEC strains isolated from UTI samples. The isolated phages were assessed for their ability to target and lyse UPEC in vitro, focusing on their efficacy in disrupting biofilms, a key virulence factor contributing to UTI recurrence and antibiotic resistance. The morphological structure observed by TEM belongs to Myoviridae, the phage exhibited icosahedral symmetry with a long non-constricting tail, the approximate measurement of the phage head was 39nm in diameter, and the phage tail was 105.317nm in length. One-step growth experiments showed that the latent period was approximately 20 min, followed by a rise period of 40 min, and a growth plateau was reached within 20 min and the burst size observed was 26 phages/ infected bacterial cells. These phages were capable of killing cells within the biofilms, leading to a reduction in living cell counts after a single treatment. This study highlights the potential of phages to play a significant role in disrupting, inactivating, and destroying Uropathogenic Escherichia coli (UPEC) biofilms. Such findings could be instrumental in developing treatment strategies that complement antibiotics and disinfectants. The phage-antibiotic synergistic activity was compared to have the possibility to facilitate the advancement of focused and enduring alternatives to traditional antibiotic therapies for UTIs.},
}

@article {pmid38971825,
year = {2024},
author = {Choi, HY and Kim, WG},
title = {Tyrosol blocks E. coli anaerobic biofilm formation via YbfA and FNR to increase antibiotic susceptibility.},
journal = {Nature communications},
volume = {15},
number = {1},
pages = {5683},
pmid = {38971825},
issn = {2041-1723},
mesh = {*Biofilms/drug effects/growth & development ; *Phenylethyl Alcohol/analogs & derivatives/pharmacology ; *Anti-Bacterial Agents/pharmacology ; *Escherichia coli/drug effects ; *Pseudomonas aeruginosa/drug effects/physiology ; *Nitric Oxide/metabolism ; Escherichia coli Proteins/metabolism/genetics/antagonists & inhibitors ; Anaerobiosis/drug effects ; Microbial Sensitivity Tests ; Gene Expression Regulation, Bacterial/drug effects ; Cyclic GMP/metabolism/analogs & derivatives ; Bacterial Proteins/metabolism/genetics/antagonists & inhibitors ; },
abstract = {Bacteria within mature biofilms are highly resistant to antibiotics than planktonic cells. Oxygen limitation contributes to antibiotic resistance in mature biofilms. Nitric oxide (NO) induces biofilm dispersal; however, low NO levels stimulate biofilm formation, an underexplored process. Here, we introduce a mechanism of anaerobic biofilm formation by investigating the antibiofilm activity of tyrosol, a component in wine. Tyrosol inhibits E. coli and Pseudomonas aeruginosa biofilm formation by enhancing NO production. YbfA is identified as a target of tyrosol and its downstream targets are sequentially determined. YbfA activates YfeR, which then suppresses the anaerobic regulator FNR. This suppression leads to decreased NO production, elevated bis-(3'-5')-cyclic dimeric GMP levels, and finally stimulates anaerobic biofilm formation in the mature stage. Blocking YbfA with tyrosol treatment renders biofilm cells as susceptible to antibiotics as planktonic cells. Thus, this study presents YbfA as a promising antibiofilm target to address antibiotic resistance posed by biofilm-forming bacteria, with tyrosol acting as an inhibitor.},
}

*Biofilms/drug effects/growth & development
*Phenylethyl Alcohol/analogs & derivatives/pharmacology
*Anti-Bacterial Agents/pharmacology
*Escherichia coli/drug effects
*Pseudomonas aeruginosa/drug effects/physiology
*Nitric Oxide/metabolism
Escherichia coli Proteins/metabolism/genetics/antagonists & inhibitors
Anaerobiosis/drug effects
Microbial Sensitivity Tests
Gene Expression Regulation, Bacterial/drug effects
Cyclic GMP/metabolism/analogs & derivatives
Bacterial Proteins/metabolism/genetics/antagonists & inhibitors

@article {pmid38971078,
year = {2024},
author = {Ren, Y and Oleszkiewicz, JA and Uyaguari, M and Devlin, TR},
title = {Response and recovery of nitrifying moving bed biofilm reactor systems exposed to 1°C with varying levels of ammonia starvation.},
journal = {Water research},
volume = {261},
number = {},
pages = {122026},
doi = {10.1016/j.watres.2024.122026},
pmid = {38971078},
issn = {1879-2448},
abstract = {This study investigated the impact of varying total ammonia nitrogen (TAN) feed levels along with water temperature decreases on the performance of nitrifying moving bed biofilm reactor (MBBR) at 1 °C and its recovery at 3 °C. Five MBBR reactors were operated with different TAN concentrations as water temperature decreased from 20 to 3 °C: reactor R1 at 30 mg N/L, reactor R2 at 20 mg N/L, reactor R3 at 15 mg N/L, reactor R4 at 10 mg N/L and reactor R5 at 0 mg N/L. The corresponding biofilm characteristics were also analyzed to understand further nitrifying MBBR under different TAN feeding scenarios. The findings revealed that the higher TAN levels were before reaching 1 °C, the better nitrification performance and the more biomass grew. However, the highest TAN concentration (30 mg N/L) might negatively affect the nitrification performance, the activity of nitrifiers, and the growth of biofilms at 1 °C because of the toxic effects of un-ionized or free ammonia (FA). It was observed that the activities of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) were affected by FA concentrations ranging from 0.2 to 0.7 mg N/L at 1 °C, but they could gradually be adapted to such inhibitory environment, with NOB recovering more quickly and robustly than AOB. The study identified 20 mg N/L (67 % of maximum influent TAN at 1 °C in R2 as the optimal TAN feeding concentration, achieving over 90 % TAN removal and a surface area removal rate (SARR) of 0.78 ± 0.02 g N/m[2]·d at 1 °C. Meanwhile, R2 also exhibited the highest biofilm mass, with total solids at 13.3 mg/carrier and volatile solids at 11.3 mg/carrier. As TAN was removed, nitrite accumulation was observed at 1 °C, and higher influent TAN concentrations prior to 1 °C appeared to delay the accumulation. When water temperature increased from 1 °C to 3 °C, nitrification performance improved significantly in all reactors without nitrite accumulation, and the higher TAN feeding in the previous stage led to faster recovery. Compared with 20 °C, biofilm became thinner and denser at 1 °C and 3 °C. Furthermore, this study revealed significant shifts in microbial community composition and nitrifier abundances in response to changes in water temperature and influent TAN levels. The dominant nitrifiers were identified as Nitrosomonadaceae (AOB) and Nitrospiraceae (NOB). At 1 °C, the nitrifier abundances were significantly correlated with SARRs, FA, and biofilm density. R2, which exhibited the best nitrification performance, maintained higher nitrifier abundances at 1 °C.},
}

@article {pmid38971076,
year = {2024},
author = {Yu, M and Guo, W and Liang, Y and Xiang, H and Xia, Y and Feng, H},
title = {Towards rapid formation of electroactive biofilm: insights from thermodynamics and electric field manipulation.},
journal = {Water research},
volume = {261},
number = {},
pages = {121992},
doi = {10.1016/j.watres.2024.121992},
pmid = {38971076},
issn = {1879-2448},
abstract = {Electroactive biofilm (EAB) has garnered significant attention due to its effectiveness in pollutant remediation, electricity generation, and chemical synthesis. However, achieving precise control over the rapid formation of EAB presents challenges for the practical implementation of bioelectrochemical technology. In this study, we investigated the regulation of EAB formation by manipulating applied electric potential. We developed a modified XDLVO model for the applied electric field and quantitatively assessed the feasibility of existing rapid formation strategies for EAB. Our results revealed that electrostatic (EL) force significantly influenced EAB formation in the presence of the applied electric field, with the potential difference between the electrode and the microbial solution being the primary determinant of EL force. Compared to -0.2 V and 0 V vs.Ag/AgCl, EAB exhibited the highest electrochemical performance at 0.2 V vs.Ag/AgCl, with a maximum current density of 6.044 ± 0.10 A/m[2], surpassing that at -0.2 V vs.Ag/AgCl and 0 V vs.Ag/AgCl by 1.73 times and 1.31 times, respectively. Furthermore, EAB demonstrated the highest biomass accumulation, measuring a thickness of 25 ± 2 μm at 0.2 V vs. Ag/AgCl, representing increases of 1.67 and 1.25 times compared to -0.2 V vs.Ag/AgCl and 0 V vs.Ag/AgCl, respectively. The strong electrostatic attraction under the anodic potential promoted the formation of a monolayer of biofilm. Additionally, the hydrophilicity and hydrophobicity of the biofilm were altered following inversion culture. The Lewis acid-base (AB) attraction offset the electrostatic repulsion caused by negative charges, it is beneficial for the formation of biofilms. This study, for the first time, elucidated the difference in the formation of cathode and anode biofilm from a thermodynamic perspective in the context of electric field introduction, laying the theoretical foundation for the directional regulation of the rapid formation of typical electroactive biofilms.},
}

@article {pmid38969785,
year = {2024},
author = {Rafique, M and Naveed, M and Mumtaz, MZ and Niaz, A and Alamri, S and Siddiqui, MH and Waheed, MQ and Ali, Z and Naman, A and Rehman, SU and Brtnicky, M and Mustafa, A},
title = {Unlocking the potential of biofilm-forming plant growth-promoting rhizobacteria for growth and yield enhancement in wheat (Triticum aestivum L.).},
journal = {Scientific reports},
volume = {14},
number = {1},
pages = {15546},
pmid = {38969785},
issn = {2045-2322},
mesh = {*Triticum/microbiology/growth & development ; *Biofilms/growth & development ; *Rhizosphere ; *Plant Roots/microbiology/growth & development ; *Soil Microbiology ; Bacteria/classification/genetics/metabolism/growth & development/isolation & purification ; Plant Development ; Biomass ; },
abstract = {Plant growth-promoting rhizobacteria (PGPR) boost crop yields and reduce environmental pressures through biofilm formation in natural climates. Recently, biofilm-based root colonization by these microorganisms has emerged as a promising strategy for agricultural enhancement. The current work aims to characterize biofilm-forming rhizobacteria for wheat growth and yield enhancement. For this, native rhizobacteria were isolated from the wheat rhizosphere and ten isolates were characterized for plant growth promoting traits and biofilm production under axenic conditions. Among these ten isolates, five were identified as potential biofilm-producing PGPR based on in vitro assays for plant growth-promoting traits. These were further evaluated under controlled and field conditions for their impact on wheat growth and yield attributes. Surface-enhanced Raman spectroscopy analysis further indicated that the biochemical composition of the biofilm produced by the selected bacterial strains includes proteins, carbohydrates, lipids, amino acids, and nucleic acids (DNA/RNA). Inoculated plants in growth chamber resulted in larger roots, shoots, and increase in fresh biomass than controls. Similarly, significant increases in plant height (13.3, 16.7%), grain yield (29.6, 17.5%), number of tillers (18.7, 34.8%), nitrogen content (58.8, 48.1%), and phosphorus content (63.0, 51.0%) in grains were observed in both pot and field trials, respectively. The two most promising biofilm-producing isolates were identified through 16 s rRNA partial gene sequencing as Brucella sp. (BF10), Lysinibacillus macroides (BF15). Moreover, leaf pigmentation and relative water contents were significantly increased in all treated plants. Taken together, our results revealed that biofilm forming PGPR can boost crop productivity by enhancing growth and physiological responses and thus aid in sustainable agriculture.},
}

*Triticum/microbiology/growth & development
*Biofilms/growth & development
*Rhizosphere
*Plant Roots/microbiology/growth & development
*Soil Microbiology
Bacteria/classification/genetics/metabolism/growth & development/isolation & purification
Plant Development
Biomass

@article {pmid38969189,
year = {2024},
author = {Hasan, M and Kim, J and Liao, X and Ding, T and Ahn, J},
title = {Antibacterial activity of bacteriophage-encoded endolysins against planktonic and biofilm cells of pathogenic Escherichia coli.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {106780},
doi = {10.1016/j.micpath.2024.106780},
pmid = {38969189},
issn = {1096-1208},
abstract = {This study was designed to assess the possibility of using bacteriophage-encoded endolysins for controlling planktonic and biofilm cells. The endolysins, LysEP114 and LysEP135, were obtained from plasmid vectors containing the endolysin genes derived from Escherichia coli phages. The high identity (>96%) was observed between LysEP114 and LysEP135. LysEP114 and LysEP135 were characterized by pH, thermal, and lactic acid stability, lytic spectrum, antibacterial activity, and biofilm eradication. The molecular masses of LysEP114 and LysEP135 were 18.2 kDa, identified as muramidases. LysEP114 and LysEP135 showed high lytic activity against the outer membrane-permeabilized E. coli KCCM 40405 at below 37°C, between pH 5 to 11, and below 70 mM of lactic acid. LysEP114 and LysEP135 showed the broad rang of lytic activity against E. coli KACC 10115, S. Typhimurium KCCM 40253, S. Typhimurium CCARM 8009, tetracycline-resistant S. Typhimurium, polymyxin B-resistant S. Typhimurium, chloramphenicol-resistant S. Typhimurium, K. pneumoniae ATCC 23357, K. pneumoniae CCARM 10237, and Shigella boydii KACC 10792. LysEP114 and LysEP135 effectively reduced the numbers of planktonic E. coli KCCM by 1.7 and 2.1 log, respectively, when treated with 50 mM lactic acid. The numbers of biofilm cells were reduced from 7.3 to 4.1 log CFU/ml and 2.2 log CFU/ml, respectively, when treated with LysEP114- and LysEP135 in the presence of 50 mM lactic acid. The results suggest that the endolysins in combination with lactic acid could be potential alternative therapeutic agents for controlling planktonic and biofilm cells.},
}

@article {pmid38969185,
year = {2024},
author = {Jang, JH and Lee, JE and Kim, KT and Ahn, DU and Paik, HD},
title = {Anti-biofilm effect of enzymatic hydrolysates of ovomucin in Listeria monocytogenes and Staphylococcus aureus.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {106771},
doi = {10.1016/j.micpath.2024.106771},
pmid = {38969185},
issn = {1096-1208},
abstract = {Despite modern advances in food hygiene, food poisoning due to microbial contamination remains a global problem, and poses a great threat to human health. Especially, Listeria monocytogenes and Staphylococcus aureus are gram-positive bacteria found on food-contact surfaces with biofilms. These foodborne pathogens cause a considerable number of food poisoning and infections annually. Ovomucin (OM) is a water-insoluble gel-type glycoprotein in egg whites. Enzymatic hydrolysis can be used to improve the bioactive properties of OM. This study aimed to investigate whether ovomucin hydrolysates (OMHs) produced using five commercial enzymes (Alcalase®, Bromelain, α-Chymotrypsin, Papain, and Pancreatin) can inhibit the biofilm formation of L. monocytogenes ATCC 15313, L. monocytogenes H7962, S. aureus KCCM 11593, and S. aureus 7. Particularly, OMH prepared with papain (OMPP; 500 μg/mL) significantly inhibited biofilm formation in L. monocytogenes ATCC 15313, L. monocytogenes H7962, S. aureus KCCM 11593, and S. aureus 7 by 85.56%, 80.28%, 91.70%, and 79.00%, respectively. In addition, OMPP reduced the metabolic activity, exopolysaccharide production (EPS), adhesion ability, and gene expression associated with the biofilm formation of these bacterial strains. These results suggest that OMH, especially OMPP, exerts anti-biofilm effects against L. monocytogenes and S. aureus. Therefore, OMPP can be used as a natural anti-biofilm agent to control food poisoning in the food industry.},
}

@article {pmid38968915,
year = {2024},
author = {Eivazzadeh-Keihan, R and Nokandeh, SM and Aliabadi, HAM and Lalebeigi, F and Kashtiaray, A and Mahdavi, M and Sehat, S and Cohan, RA and Maleki, A},
title = {Unveiling the synergy: Biocompatible alginate-cellulose hydrogel loaded with silk fibroin and zinc ferrite nanoparticles for enhanced cell adhesion, and anti-biofilm activity.},
journal = {International journal of biological macromolecules},
volume = {275},
number = {Pt 1},
pages = {133412},
doi = {10.1016/j.ijbiomac.2024.133412},
pmid = {38968915},
issn = {1879-0003},
abstract = {Combining a biocompatible hydrogel scaffold with the cell-supportive properties of silk fibroin (SF) and the unique functionalities of ZnFe2O4 nanoparticles creates a promising platform for advanced nanobiomaterials. The research is centered on synthesizing a natural hydrogel using cellulose (Cellul) and sodium alginate (SA) combined with SF and zinc ferrite nanoparticles. A range of analytical and biological assays were conducted to determine the biological and physicochemical properties of the nanobiocomposite. The hemolysis and 2,5-diphenyl-2H-tetrazolium bromide (MTT) assays indicated that the SA-Cellul hydrogel/SF/ZnFe2O4 nanobiocomposite was a biocompatible against human dermal fibroblasts (Hu02) and red blood cells (RBC). In addition, aside from demonstrating outstanding anti-biofilm activity, the nanobiocomposite also promotes the Hu02 cells adhesion, showcasing the synergistic effect of incorporating SF and ZnFe2O4 nanoparticle. These promising results show that this nanobiocomposite has potential applications in various biomedical fields.},
}

@article {pmid38967798,
year = {2024},
author = {Li, M and Cruz, CD and Ilina, P and Tammela, P},
title = {High-throughput combination assay for studying biofilm formation of uropathogenic Escherichia coli.},
journal = {Archives of microbiology},
volume = {206},
number = {8},
pages = {344},
pmid = {38967798},
issn = {1432-072X},
mesh = {*Biofilms/drug effects/growth & development ; *Uropathogenic Escherichia coli/drug effects/physiology ; *High-Throughput Screening Assays/methods ; *Xanthenes/chemistry ; *Anti-Bacterial Agents/pharmacology ; *Gentian Violet/metabolism ; *Oxazines/pharmacology/metabolism/chemistry ; Microbial Sensitivity Tests ; Urinary Tract Infections/microbiology ; Humans ; },
abstract = {Uropathogenic Escherichia coli, the most common cause for urinary tract infections, forms biofilm enhancing its antibiotic resistance. To assess the effects of compounds on biofilm formation of uropathogenic Escherichia coli UMN026 strain, a high-throughput combination assay using resazurin followed by crystal violet staining was optimized for 384-well microplate. Optimized assay parameters included, for example, resazurin and crystal violet concentrations, and incubation time for readouts. For the assay validation, quality parameters Z' factor, coefficient of variation, signal-to-noise, and signal-to-background were calculated. Microplate uniformity, signal variability, edge well effects, and fold shift were also assessed. Finally, a screening with known antibacterial compounds was conducted to evaluate the assay performance. The best conditions found were achieved by using 12 µg/mL resazurin for 150 min and 0.023% crystal violet. This assay was able to detect compounds displaying antibiofilm activity against UMN026 strain at sub-inhibitory concentrations, in terms of metabolic activity and/or biomass.},
}

*Biofilms/drug effects/growth & development
*Uropathogenic Escherichia coli/drug effects/physiology
*High-Throughput Screening Assays/methods
*Xanthenes/chemistry
*Anti-Bacterial Agents/pharmacology
*Gentian Violet/metabolism
*Oxazines/pharmacology/metabolism/chemistry
Microbial Sensitivity Tests
Urinary Tract Infections/microbiology
Humans

@article {pmid38966810,
year = {2024},
author = {Wani, MY and Srivastava, V and El-Said, WA and Al-Bogami, AS and Ahmad, A},
title = {Inhibition of apoptosis and biofilm formation in Candida auris by click-synthesized triazole-bridged quinoline derivatives.},
journal = {RSC advances},
volume = {14},
number = {29},
pages = {21190-21202},
pmid = {38966810},
issn = {2046-2069},
abstract = {Candida auris, a recent addition to the Candida species, poses a significant threat with its association to numerous hospital outbreaks globally, particularly affecting immunocompromised individuals. Given its resistance to existing antifungal therapies, there is a pressing need for innovative treatments. In this study, novel triazole bridged quinoline derivatives were synthesized and evaluated for their antifungal activity against C. auris. The most promising compound, QT7, demonstrated exceptional efficacy with a minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of 0.12 μg mL[-1] and 0.24 μg mL[-1], respectively. Additionally, QT7 effectively disrupted mature biofilms, inhibiting them by 81.98% ± 8.51 and 89.57 ± 5.47 at MFC and 2× MFC values, respectively. Furthermore, QT7 induced cellular apoptosis in a dose-dependent manner, supported by various apoptotic markers such as phosphatidylserine externalization, mitochondrial depolarization, and reduced cytochrome c and oxidase activity. Importantly, QT7 exhibited low hemolytic activity, highlighting its potential for further investigation. Additionally, the physicochemical properties of this compound suggest its potential as a lead drug candidate, warranting further exploration in drug discovery efforts against Candida auris infections.},
}

@article {pmid38966782,
year = {2024},
author = {Rohilla, A and Kumar, V and Ahire, JJ},
title = {Unveiling the persistent threat: recent insights into Listeria monocytogenes adaptation, biofilm formation, and pathogenicity in foodborne infections.},
journal = {Journal of food science and technology},
volume = {61},
number = {8},
pages = {1428-1438},
pmid = {38966782},
issn = {0022-1155},
abstract = {Listeriosis is a severe disease caused by the foodborne pathogen Listeria monocytogenes, posing a significant risk to vulnerable populations such as the elderly, pregnant women, and newborns. While relatively uncommon, it has a high global mortality rate of 20-30%. Recent research indicates that smaller outbreaks of the more severe, invasive form of the disease occur more frequently than previously thought, despite the overall stable infection rates of L. monocytogenes over the past 10 years. The ability of L. monocytogenes to form biofilm structures on various surfaces in food production environments contributes to its persistence and challenges in eradication, potentially leading to contamination of food and food production facilities. To address these concerns, this review focuses on recent developments in epidemiology, risk evaluations, and molecular mechanisms of L. monocytogenes survival in adverse conditions and environmental adaptation. Additionally, it covers new insights into strain variability, pathogenicity, mutations, and host vulnerability, emphasizing the important events framework that elucidates the biochemical pathways from ingestion to infection. Understanding the adaptation approaches of L. monocytogenes to environmental stress factors is crucial for the development of effective and affordable pathogen control techniques in the food industry, ensuring the safety of food production.},
}

@article {pmid38965339,
year = {2024},
author = {Nair, VG and Srinandan, CS and Rajesh, YBRD and Narbhavi, D and Anupriya, A and Prabhusaran, N and Nagarajan, S},
title = {Biogenic amine tryptamine in human vaginal probiotic isolates mediates matrix inhibition and thwarts uropathogenic E. coli biofilm.},
journal = {Scientific reports},
volume = {14},
number = {1},
pages = {15387},
pmid = {38965339},
issn = {2045-2322},
support = {DST/WOS-B/HN-32/2021//Department of Science and Technology, Ministry of Science and Technology, India/ ; 67/5/2020-DDI/BMS//Indian Council of Medical Research/ ; },
mesh = {*Biofilms/drug effects/growth & development ; Humans ; *Tryptamines/pharmacology ; Female ; *Uropathogenic Escherichia coli/drug effects/physiology ; *Probiotics/pharmacology ; *Vagina/microbiology ; *Lactobacillus/drug effects/metabolism/physiology ; Escherichia coli Infections/microbiology/drug therapy/prevention & control ; Adult ; Anti-Bacterial Agents/pharmacology ; },
abstract = {Probiotics offer a promising prophylactic approach against various pathogens and represent an alternative strategy to combat biofilm-related infections. In this study, we isolated vaginal commensal microbiota from 54 healthy Indian women to investigate their probiotic traits. We primarily explored the ability of cell-free supernatant (CFS) from Lactobacilli to prevent Uropathogenic Escherichia coli (UPEC) colonization and biofilm formation. Our findings revealed that CFS effectively reduced UPEC's swimming and swarming motility, decreased cell surface hydrophobicity, and hindered matrix production by downregulating specific genes (fimA, fimH, papG, and csgA). Subsequent GC-MS analysis identified Tryptamine, a monoamine compound, as the potent bioactive substance from Lactobacilli CFS, inhibiting UPEC biofilms with an MBIC of 4 µg/ml and an MBEC of 8 µg/ml. Tryptamine induced significant changes in E. coli colony biofilm morphology, transitioning from the Red, Dry, and Rough (RDAR) to the Smooth and White phenotype, indicating reduced extracellular matrix production. Biofilm time-kill assays demonstrated a four-log reduction in UPEC viability when treated with Tryptamine, highlighting its potent antibacterial properties, comparable to CFS treatment. Biofilm ROS assays indicated a significant elevation in ROS generation within UPEC biofilms, suggesting a potential antibacterial mechanism. Gene expression studies with Tryptamine-treated samples showed a reduction in expression of curli gene (csgA), consistent with CFS treatment. This study underscores the potential of Tryptamine from probiotic Lactobacilli CFS as a promising antibiofilm agent against UPEC biofilms.},
}

*Biofilms/drug effects/growth & development
Humans
*Tryptamines/pharmacology
Female
*Uropathogenic Escherichia coli/drug effects/physiology
*Probiotics/pharmacology
*Vagina/microbiology
*Lactobacillus/drug effects/metabolism/physiology
Escherichia coli Infections/microbiology/drug therapy/prevention & control
Adult
Anti-Bacterial Agents/pharmacology

@article {pmid38965139,
year = {2024},
author = {Sahin, Z and Ozer, NE and Calı, A},
title = {Biofilm inhibition of denture cleaning tablets and carvacrol on denture bases produced with different techniques.},
journal = {Clinical oral investigations},
volume = {28},
number = {7},
pages = {413},
pmid = {38965139},
issn = {1436-3771},
mesh = {*Biofilms/drug effects ; *Candida albicans/drug effects ; *Denture Bases/microbiology ; *Cymenes/pharmacology ; *Surface Properties ; *Denture Cleansers/pharmacology ; *Materials Testing ; *Microscopy, Electron, Scanning ; Printing, Three-Dimensional ; Tablets ; },
abstract = {OBJECTIVES: This study compares the biofilm inhibition effects of denture cleaning tablets, carvacrol, and their combined use against Candida albicans on denture bases produced with different techniques. Additionally, the surface roughness and contact angles of these denture bases were evaluated.

MATERIALS AND METHODS: Test samples were prepared from four different denture base materials (cold-polymerized, heat-polymerized, CAD/CAM milling, and 3D-printed). The surface roughness and contact angles of the test samples were measured using a profilometer and goniometer, respectively. For the evaluation of biofilm inhibition, samples were divided into 5 subgroups: Corega and carvacrol, separately and combined treatments, positive (inoculated with C. albicans) and negative control (non-inoculated with C. albicans, only medium). Biofilm mass was determined using the crystal violet method. An additional prepared test sample for each subgroup was examined under scanning electron microscopy (SEM).

RESULTS: The surface roughness values of the 3D-printed test samples were found to be statistically higher than the other groups (P < .001). The water contact angle of all test materials was not statistically different from each other (P > .001). Corega and carvacrol, separately and combined, significantly decreased the amount of biofilm on all surfaces (P < .0001). Treatment of corega alone and in combination with carvacrol to the 3D-printed material caused less C. albicans inhibition than the other groups (P < .001; P < .05).

CONCLUSIONS: The surface roughness values of all test groups were within the clinically acceptable threshold. Although Corega and carvacrol inhibited C. albicans biofilms, their combined use did not show a synergistic effect.

CLINICAL RELEVANCE: Carvacrol may be used as one of the disinfectant agents for denture cleaning due to its biofilm inhibition property.},
}

*Biofilms/drug effects
*Candida albicans/drug effects
*Denture Bases/microbiology
*Cymenes/pharmacology
*Surface Properties
*Denture Cleansers/pharmacology
*Materials Testing
*Microscopy, Electron, Scanning
Printing, Three-Dimensional
Tablets

@article {pmid38965060,
year = {2024},
author = {Wu, W and Wang, Y and Yang, H and Chen, H and Wang, C and Liang, J and Song, Y and Xu, S and Sun, Y and Wang, L},
title = {Antibacterial And Biofilm Removal Strategies Based On Micro/nanomotors In The Biomedical Field.},
journal = {ChemMedChem},
volume = {},
number = {},
pages = {e202400349},
doi = {10.1002/cmdc.202400349},
pmid = {38965060},
issn = {1860-7187},
abstract = {Bacterial infection, which can trigger varieties of diseases and tens of thousands of deaths each year, poses serious threats to human health. Particularly, the new dilemma caused by biofilms is gradually becoming a severe and tough problem in the biomedical field. Thus, the strategies to address these problems are considered an urgent task at present. Micro/nanomotors (MNMs), also named micro/nanoscale robots, are mostly driven by chemical energy or external field, exhibiting strong diffusion and self-propulsion in the liquid media, which has the potential for antibacterial applications. In particular, when MNMs are assembled in swarms, they become robust and efficient for biofilm removal. However, there is a lack of comprehensive review discussing the progress in this aspect. Bearing it in mind and based on our own research experience in this regard, the studies on MNMs driven by different mechanisms orchestrated for antibacterial activity and biofilm removal are timely and concisely summarized and discussed in this work, aiming to show the advantages of MNMs brought to this field. In addition, an outlook was proposed, hoping to provide the fundamental guidance for future development in this area.},
}

@article {pmid38964021,
year = {2024},
author = {Alves, F and Nakada, PJT and Marques, MJAM and Rea, LDC and Cortez, AA and Pellegrini, VOA and Polikarpov, I and Kurachi, C},
title = {Complete photodynamic inactivation of Pseudomonas aeruginosa biofilm with use of potassium iodide and its comparison with enzymatic pretreatment.},
journal = {Journal of photochemistry and photobiology. B, Biology},
volume = {257},
number = {},
pages = {112974},
doi = {10.1016/j.jphotobiol.2024.112974},
pmid = {38964021},
issn = {1873-2682},
abstract = {Pseudomonas aeruginosa, a gram-negative bacterium, accounts for 7% of all hospital-acquired infections. Despite advances in medicine and antibiotic therapy, P. aeruginosa infection still results in high mortality rates of up to 62% in certain patient groups. This bacteria is also known to form biofilms, that are 10 to 1000 times more resistant to antibiotics compared to their free-floating counterparts. Photodynamic Inactivation (PDI) has been proved to be an effective antimicrobial technique for microbial control. This method involves the incubation of the pathogen with a photosensitizer (PS), then, a light at appropriated wavelength is applied, leading to the production of reactive oxygen species that are toxic to the microbial cells. Studies have focused on strategies to enhance the PDI efficacy, such as a pre-treatment with enzymes to degrade the biofilm matrix and/or an addition of inorganic salts to the PS. The aim of the present study is to evaluate the effectiveness of PDI against P. aeruginosa biofilm in association with the application of the enzymes prior to PDI (enzymatic pre-treatment) or the addition of potassium iodide (KI) to the photosensitizer solution, to increase the inactivation effectiveness of the treatment. First, a range of enzymes and PSs were tested, and the best protocols for combined treatments were selected. The results showed that the use of enzymes as a pre-treatment was effective to reduce the total biomass, however, when associated with PDI, mild bacterial reductions were obtained. Then, the use of KI in association with the PS was evaluated and the results showed that, PDI mediated by methylene blue (MB) in the presence of KI was able to completely eradicate the biofilm. However, when the PDI was performed with curcumin and KI, no additive reduction was observed. In conclusion, out of all strategies evaluated in the present study, the most promising strategy to improve PDI against P. aeruginosa biofilm was the use of KI in association with MB, resulting in eradication with 10[8] log bacterial inactivation.},
}

@article {pmid38963508,
year = {2024},
author = {Rouhi, A and Falah, F and Azghandi, M and Alizadeh Behbahani, B and Tabatabaei-Yazdi, F and Ibrahim, SA and Dertli, E and Vasiee, A},
title = {Investigating the Effect of Melittin Peptide in Preventing Biofilm Formation, Adhesion and Expression of Virulence Genes in Listeria monocytogenes.},
journal = {Probiotics and antimicrobial proteins},
volume = {},
number = {},
pages = {},
pmid = {38963508},
issn = {1867-1314},
abstract = {Listeria monocytogenes is a notable food-borne pathogen that has the ability to create biofilms on different food processing surfaces, making it more resilient to disinfectants and posing a greater risk to human health. This study assessed melittin peptide's anti-biofilm and anti-pathogenicity effects on L. monocytogenes ATCC 19115. Melittin showed minimum inhibitory concenteration (MIC) of 100 μg/mL against this strain and scanning electron microscopy images confirmed its antimicrobial efficacy. The OD measurement demonstrated that melittin exhibited a strong proficiency in inhibiting biofilms and disrupting pre-formed biofilms at concentrations ranging from 1/8MIC to 2MIC and this amount was 92.59 ± 1.01% to 7.17 ± 0.31% and 100% to 11.50 ± 0.53%, respectively. Peptide also reduced hydrophobicity and self-aggregation of L. monocytogenes by 35.25% and 14.38% at MIC. Melittin also significantly reduced adhesion to HT-29 and Caco-2 cells by 61.33% and 59%, and inhibited invasion of HT-29 and Caco-2 cells by 49.33% and 40.66% for L. monocytogenes at the MIC value. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) revealed melittin's impact on gene expression, notably decreasing inlB (44%) and agrA (45%) gene expression in L. monocytogenes. flaA and hly genes also exhibited reduced expression. Also, significant changes were observed in sigB and prfA gene expression. These results underscore melittin's potential in combating bacterial infections and biofilm-related challenges in the food industry.},
}

@article {pmid38963393,
year = {2024},
author = {Zhou, L and Lai, CY and Wu, M and Guo, J},
title = {Simultaneous Biogas Upgrading and Valuable Chemical Production Using Homoacetogens in a Membrane Biofilm Reactor.},
journal = {Environmental science & technology},
volume = {},
number = {},
pages = {},
doi = {10.1021/acs.est.4c02021},
pmid = {38963393},
issn = {1520-5851},
abstract = {Biogas produced from anaerobic digestion usually contains impurities, particularly with a high content of CO2 (15-60%), thus decreasing its caloric value and limiting its application as an energy source. H2-driven biogas upgrading using homoacetogens is a promising approach for upgrading biogas to biomethane and converting CO2 to acetate simultaneously. Herein, we developed a novel membrane biofilm reactor (MBfR) with H2 and biogas separately supplied via bubbleless hollow fiber membranes. The gas-permeable hollow fibers of the MBfR enabled high H2 and CO2 utilization efficiencies (∼98% and ∼97%, respectively) and achieved concurrent biomethane (∼94%) and acetate (∼450 mg/L/d) production. High-throughput 16S rRNA gene amplicon sequencing suggested that enriched microbial communities were dominated by Acetobacterium (38-48% relative abundance). In addition, reverse transcription quantitative PCR of the functional marker gene formyltetrahydrofolate synthetase showed that its expression level increased with increasing H2 and CO2 utilization efficiencies. These results indicate that Acetobacterium plays a key role in CO2 to acetate conversion. These findings are expected to facilitate energy-positive wastewater treatment and contribute to the development of a new solution to biogas upgrading.},
}

@article {pmid38962288,
year = {2024},
author = {Al Ansari, N and Abid, M},
title = {Enhancing Presurgical Infant Orthopedic Appliances: Characterization, Mechanics, and Biofilm Inhibition of a Novel Chlorhexidine-Halloysite Nanotube-Modified PMMA.},
journal = {International journal of biomaterials},
volume = {2024},
number = {},
pages = {6281972},
pmid = {38962288},
issn = {1687-8787},
abstract = {OBJECTIVES: This in vitro study aimed to develop a novel nanocomposite acrylic resin with inherent antimicrobial properties. This study evaluated its effectiveness against microbial biofilm formation, while also assessing its physical and mechanical properties.

METHODS: Polymethylmethacrylate (PMMA) was modified with four different concentrations of chlorhexidine halloysite nanotubes (CHX-HNTs): 1%, 1.5%, 3%, and 4.5 wt.% by weight, along with a control group (0 wt.% CHX-HNTs). The biofilm inhibition ability of the modified CHX-HNTs acrylic against Candida albicans, Staphylococcus aureus, Streptococcus pneumoniae, and Streptococcus agalactiae was assessed using microtiter biofilm test. In addition, ten samples from each group were then tested for flexural strength, surface roughness, and hardness. Statistical analysis was performed using one-way ANOVA and Tukey's test for comparison (P < 0.05).

RESULTS: CHX-HNTs effectively reduced the adhesion of Candida albicans and bacteria to the PMMA in a dose-dependent manner. The higher the concentration of CHX-HNTs, the greater the reduction in microbial adhesion, with the highest concentration (4.5 wt.%) showing the most significant effect with inhibition rates ≥98%. The addition of CHX-HNTs at any tested concentration (1%, 1.5%, 3%, and 4.5 wt.%) did not cause any statistically significant difference in the flexural strength, surface roughness, or hardness of the PMMA compared to the control group.

CONCLUSIONS: The novel integration of CHX-HNT fillers shows promising results as an effective biofilm inhibitor on acrylic appliances. This new approach has the potential to successfully control infectious diseases without negatively affecting the mechanical properties of the acrylic resin. Clinical Relevance. The integration of CHX-HNTs into presurgical infant orthopedic appliances should be thoroughly assessed as a promising preventive measure to mitigate microbial infections. This evaluation holds significant potential for controlling infectious diseases among infants with cleft lip and palate, thereby offering a valuable contribution to their overall well-being.},
}

@article {pmid38961344,
year = {2024},
author = {Yu, J and Han, W and Xu, Y and Shen, L and Zhao, H and Zhang, J and Xiao, Y and Guo, Y and Yu, F},
title = {Biofilm-producing ability of methicillin-resistant Staphylococcus aureus clinically isolated in China.},
journal = {BMC microbiology},
volume = {24},
number = {1},
pages = {241},
pmid = {38961344},
issn = {1471-2180},
support = {82202587//The Natural Science Fund of China/ ; },
mesh = {*Biofilms/growth & development ; China ; *Methicillin-Resistant Staphylococcus aureus/genetics/isolation & purification/physiology/drug effects/classification ; Humans ; *Staphylococcal Infections/microbiology ; *Anti-Bacterial Agents/pharmacology ; *Microbial Sensitivity Tests ; },
abstract = {BACKGROUND: Staphylococcus aureus, a commensal bacterium, colonizes the skin and mucous membranes of approximately 30% of the human population. Apart from conventional resistance mechanisms, one of the pathogenic features of S. aureus is its ability to survive in a biofilm state on both biotic and abiotic surfaces. Due to this characteristic, S. aureus is a major cause of human infections, with Methicillin-Resistant Staphylococcus aureus (MRSA) being a significant contributor to both community-acquired and hospital-acquired infections.

RESULTS: Analyzing non-repetitive clinical isolates of MRSA collected from seven provinces and cities in China between 2014 and 2020, it was observed that 53.2% of the MRSA isolates exhibited varying degrees of ability to produce biofilm. The biofilm positivity rate was notably high in MRSA isolates from Guangdong, Jiangxi, and Hubei. The predominant MRSA strains collected in this study were of sequence types ST59, ST5, and ST239, with the biofilm-producing capability mainly distributed among moderate and weak biofilm producers within these ST types. Notably, certain sequence types, such as ST88, exhibited a high prevalence of strong biofilm-producing strains. The study found that SCCmec IV was the predominant type among biofilm-positive MRSA, followed by SCCmec II. Comparing strains with weak and strong biofilm production capabilities, the positive rates of the sdrD and sdrE were higher in strong biofilm producers. The genetic determinants ebp, icaA, icaB, icaC, icaD, icaR, and sdrE were associated with strong biofilm production in MRSA. Additionally, biofilm-negative MRSA isolates showed higher sensitivity rates to cefalotin (94.8%), daptomycin (94.5%), mupirocin (86.5%), teicoplanin (94.5%), fusidic acid (81.0%), and dalbavancin (94.5%) compared to biofilm-positive MRSA isolates. The biofilm positivity rate was consistently above 50% in all collected specimen types.

CONCLUSIONS: MRSA strains with biofilm production capability warrant increased vigilance.},
}

*Biofilms/growth & development
China
*Methicillin-Resistant Staphylococcus aureus/genetics/isolation & purification/physiology/drug effects/classification
Humans
*Staphylococcal Infections/microbiology
*Anti-Bacterial Agents/pharmacology
*Microbial Sensitivity Tests

@article {pmid38960353,
year = {2024},
author = {Zhang, S and Huang, X and Dong, W and Wang, H and Hu, L and Zhou, G and Zheng, Z},
title = {Potential effects of Cu[2+] stress on nitrogen removal performance, microbial characteristics, and metabolism pathways of biofilm reactor.},
journal = {Environmental research},
volume = {},
number = {},
pages = {119541},
doi = {10.1016/j.envres.2024.119541},
pmid = {38960353},
issn = {1096-0953},
abstract = {Sequencing batch biofilm reactors (SBBR) were utilized to investigate the impact of Cu[2+] on nitrogen (N) removal and microbial characteristics. The result indicated that the low concentration of Cu[2+] (0.5 mg L[-1]) facilitated the removal of ammonia nitrogen (NH4[+]-N), total nitrogen (TN), nitrate nitrogen (NO3[-]-N), and chemical oxygen demand (COD). In comparison to the average effluent concentration of the control group, the average effluent concentrations of NH4[+]-N, NO3[-]-N, COD, and TN were found to decrease by 40.53%, 17.02%, 10.73%, and 15.86%, respectively. Conversely, the high concentration of Cu[2+] (5 mg L[-1]) resulted in an increase of 94.27%, 55.47%, 22.22%, and 14.23% in the aforementioned parameters, compared to the control group. Low concentrations of Cu[2+] increased the abundance of nitrifying bacteria (Rhodanobacter, unclassified-o-Sacharimonadales), denitrifying bacteria (Thermomonas, Comamonas), denitrification-associated genes (hao, nosZ, norC, nffA, nirB, nick, and nifD), and heavy-metal-resistant genes related to Cu[2+] (pcoB, cutM, cutC, pcoA, copZ) to promote nitrification and denitrification. Conversely, high concentration Cu[2+] hindered the interspecies relationship among denitrifying bacteria genera, nitrifying bacteria genera, and other genera, reducing denitrification and nitrification efficiency. Cu[2+] involved in the N and tricarboxylic acid (TCA) cycles, as evidenced by changes in the abundance of key enzymes, such as (EC:1.7.99.1), (EC:1.7.2.4), and (EC:1.1.1.42), which initially increased and then decreased with varying concentrations of Cu[2+]. Conversely, the abundance of EC1.7.2.1, associated with the accumulation of nitrite nitrogen (NO2[-]-N), gradually declined. These findings provided insights into the impact of Cu[2+] on biological N removal.},
}

@article {pmid38960350,
year = {2024},
author = {Ugya, AY and Hasan, DB and Ari, HA and Sheng, Y and Chen, H and Wang, Q},
title = {Antibiotic synergistic effect surge bioenergy potential and pathogen resistance of Chlorella variabilis biofilm.},
journal = {Environmental research},
volume = {259},
number = {},
pages = {119521},
doi = {10.1016/j.envres.2024.119521},
pmid = {38960350},
issn = {1096-0953},
abstract = {Tetracycline (TC) and ciprofloxacin (CF) induce a synergistic effect that alters the biochemical composition, leading to a decrease in the growth and photosynthetic efficiency of microalgae. But the current study provides a novel insight into stress-inducing techniques that trigger a change in macromolecules, leading to an increase in the bioenergy potential and pathogen resistance of Chlorella variabilis biofilm. The study revealed that in a closed system, a light intensity of 167 μmol/m[2]/s causes 93.5% degradation of TC and 16% degradation of CF after 7 days of exposure, hence availing the products for utilization by C. variabilis biofilm. The resistance to pathogens invasion was linked to 85% and 40% increase in the expression level of photosystem II oxygen-evolving enhancer protein 3 (PsbQ), and mitogen activated kinase (MAK) respectively. The results also indicate that a surge in light intensity triggers 49% increase in the expression level of lysophosphatidylcholine (LPC) (18:2), which is an important lipidomics that can easily undergo transesterification into bioenergy. The thermogravimetric result indicates that the biomass sample of C. variabilis biofilm cultivated under light intensity of 167 μmol/m2/s produces a higher residual mass of 45.5% and 57.5 under air and inert conditions, respectively. The Fourier transform infrared (FTIR) indicates a slight shift in the major functional groups, while the energy-dispersive X-ray spectroscopy (SEM-EDS) and X-ray fluorescence (XRF) indicate clear differences in the morphology and elemental composition of the biofilm biomass in support of the increase bioenergy potential of C. variabilis biofilm. The current study provides a vital understanding of a innovative method of cultivation of C. variabilis biofilm, which is resistant to pathogens and controls the balance between fatty acid and TAG synthesis leading to surge in bioenergy potential and environmental sustainability.},
}

@article {pmid38958241,
year = {2024},
author = {Zuo, XS and Wang, QY and Wang, SS and Li, G and Zhan, LY},
title = {The role of N-acetylcysteine on adhesion and biofilm formation of Candida parapsilosis isolated from catheter-related candidemia.},
journal = {Journal of medical microbiology},
volume = {73},
number = {7},
pages = {},
doi = {10.1099/jmm.0.001848},
pmid = {38958241},
issn = {1473-5644},
mesh = {*Biofilms/drug effects/growth & development ; *Acetylcysteine/pharmacology ; Humans ; *Candida parapsilosis/drug effects/genetics/physiology ; *Catheter-Related Infections/microbiology ; *Candidemia/microbiology ; Fungal Proteins/genetics/metabolism ; Antifungal Agents/pharmacology ; },
abstract = {Objectives. Anti-fungal agents are increasingly becoming less effective due to the development of resistance. In addition, it is difficult to treat Candida organisms that form biofilms due to a lack of ability of drugs to penetrate the biofilms. We are attempting to assess the effect of a new therapeutic agent, N-acetylcysteine (NAC), on adhesion and biofilm formation in Candida parapsilosis clinical strains. Meanwhile, to detect the transcription level changes of adhesion and biofilm formation-associated genes (CpALS6, CpALS7, CpEFG1 and CpBCR1) when administrated with NAC in C. parapsilosis strains, furthermore, to explore the mechanism of drug interference on biofilms.Hypothesis/Gap statement. N-acetylcysteine (NAC) exhibits certain inhibitory effects on adhesion and biofilm formation in C. parapsilosis clinical strains from CRBSIs through: (1) down-regulating the expression of the CpEFG1 gene, making it a highly potential candidate for the treatment of C. parapsilosis catheter-related bloodstream infections (CRBSIs), (2) regulating the metabolism and biofilm -forming factors of cell structure.Methods. To determine whether non-antifungal agents can exhibit inhibitory effects on adhesion, amounts of total biofilm formation and metabolic activities of C. parapsilosis isolates from candidemia patients, NAC was added to the yeast suspensions at different concentrations, respectively. Reverse transcription was used to detect the transcriptional levels of adhesion-related genes (CpALS6 and CpALS7) and biofilm formation-related factors (CpEFG1 and CpBCR1) in the BCR1 knockout strain, CP7 and CP5 clinical strains in the presence of NAC. To further explore the mechanism of NAC on the biofilms of C. parapsilosis, RNA sequencing was used to calculate gene expression, comparing the differences among samples. Gene Ontology (GO) enrichment analysis helps to illustrate the difference between two particular samples on functional levels.Results. A high concentration of NAC reduces the total amount of biofilm formation in C. parapsilosis. Following co-incubation with NAC, the expression of CpEFG1 in both CP7 and CP5 clinical strains decreased, while there were no significant changes in the transcriptional levels of CpBCR1 compared with the untreated strain. GO enrichment analysis showed that the metabolism and biofilm-forming factors of cell structure were all regulated after NAC intervention.Conclusions. The non-antifungal agent NAC exhibits certain inhibitory effects on clinical isolate biofilm formation by down-regulating the expression of the CpEFG1 gene, making it a highly potential candidate for the treatment of C. parapsilosis catheter-related bloodstream infections.},
}

*Biofilms/drug effects/growth & development
*Acetylcysteine/pharmacology
Humans
*Candida parapsilosis/drug effects/genetics/physiology
*Catheter-Related Infections/microbiology
*Candidemia/microbiology
Fungal Proteins/genetics/metabolism
Antifungal Agents/pharmacology

@article {pmid38955982,
year = {2024},
author = {Teixeira, IM and de Moraes Assumpção, Y and Paletta, ACC and Antunes, M and da Silva, IT and Jaeger, LH and Ferreira, RF and de Oliveira Ferreira, E and de Araújo Penna, B},
title = {Investigation on biofilm composition and virulence traits of S. pseudintermedius isolated from infected and colonized dogs.},
journal = {Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]},
volume = {},
number = {},
pages = {},
pmid = {38955982},
issn = {1678-4405},
support = {Coordenação de Aperfeiçoamento de Pessoal de Nível Superior//Coordenação de Aperfeiçoamento de Pessoal de Nível Superior/ ; Conselho Nacional de Desenvolvimento Científico e Tecnológico//Conselho Nacional de Desenvolvimento Científico e Tecnológico/ ; Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro//Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro/ ; Bill and Melinda Gates Foundation//Bill and Melinda Gates Foundation/ ; },
abstract = {Staphylococcus pseudintermedius, which is part of the skin microbiome of dogs, causes a variety of opportunistic infections. These infections may become more difficult to treat due to the formation of biofilm. The capacity of S. pseudintermedius to form biofilm, as well as the associated genes, has not been elucidated. This study evaluated the production and composition of S. pseudintermedius biofilm. Samples were collected from both infected dogs and asymptomatic dogs. Isolates were identified using mass spectrometry and Multiplex-PCR. Biofilm production and composition were assessed using a quantitative microtiter plate assay. The presence of ica operon genes and sps genes was investigated using conventional PCR. The investigation of Agr type and virulence genes was conducted in silico on 24 sequenced samples. All strains could produce strong biofilms, with most of the isolates presenting a polysaccharide biofilm. 63.6% of the isolates carried the complete ica operon (ADBC). All samples showed the presence of the genes spsK, spsA, and spsL, while the distribution of other genes varied. Agr type III was the most prevalent (52.2%). All sequenced samples carried the cytotoxins hlb, luk-S, luk-F, as well as the exfoliative toxins siet and se_int. No isolate displayed other exfoliative toxins. Only LB1733 presented a set of different enterotoxins (sea, seb, sec_canine, seh, sek, sel, and seq). Our findings suggest that S. pseudintermedius is a strong producer of biofilm and carries virulence genes.},
}