@article {pmid39615850,
year = {2024},
author = {Gómez-Martínez, D and Selvin, MA and Nilsson, AK and Carmona, E and Ngou, JS and Kristiansson, E and Nilsson, RH and Corcoll, N},
title = {Environmental concentrations of the fungicide tebuconazole alter microbial biodiversity and trigger biofilm-released transformation products.},
journal = {Chemosphere},
volume = {},
number = {},
pages = {143854},
doi = {10.1016/j.chemosphere.2024.143854},
pmid = {39615850},
issn = {1879-1298},
abstract = {Freshwater microbial communities are integral components of riverine biodiversity. The ecological effects of toxic chemical pollutants, such as fungicides (e.g., tebuconazole), on microbial abundance and diversity are needed for risk assessment and regulation. The emergence of RNA metabarcoding approaches allow us to describe at unprecedented resolution the microbial diversity of the active part of a microbial community. Our study assesses the ecotoxicological impact of chronic and acute tebuconazole exposures on fungal, bacterial, and algal biomass and biodiversity of aquatic fungi and bacteria in stream biofilms using an RNA metabarcoding approach. In addition, the study uses HPLC-MS to evaluate the capability of biofilms to metabolize tebuconazole. Natural biofilm communities from a Swedish stream were exposed chronically (24 days) and acutely (96 hours) to environmental concentrations of tebuconazole (10 and 100 μg/L) in microcosms conditions. The diversity and community structure of fungi and bacteria was assessed by ITS2 and 16S cDNA amplicon-sequencing, respectively. Biofilms chronically exposed to tebuconazole produced and released unidentified transformation products into the water column, suggesting a biotransformation capability following 24 days of uninterrupted exposure. The fungal biomass markedly decreased by a biomass loss of 40% when chronically exposed to 10 μg/L, and 60% when chronically exposed to 100 μg/L. Bacterial and algal biomass remained comparable with the controls in all tebuconazole treatments. Fungal and bacterial alpha diversity metrics were not significantly impacted, although a decreasing trend in fungal richness was observed with the treatments. However, beta diversity was significantly impacted in both fungal and bacterial compartments. Chronic exposures resulted in a shift in community composition, where taxa potentially more tolerant to tebuconazole (i.e. Lecanoromycetes) replaced more sensitive taxa (i.e. Malasseziomycetes). This study indicates that tebuconazole at environmental concentrations might pose a risk to freshwater systems, mainly due to its high toxicity to fungi.},
}

@article {pmid39615760,
year = {2024},
author = {Ni, M and Pan, Y and Gong, J and Chen, Z and Li, D and Huang, Y and Li, L and Ding, Y and Bi, Z},
title = {Glycogen-accumulating organisms promote phosphate recovery from wastewater by pilot-scale biofilm sequencing batch reactor: Performance and mechanism.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {131910},
doi = {10.1016/j.biortech.2024.131910},
pmid = {39615760},
issn = {1873-2976},
abstract = {A high phosphate (P) recovery concentration was achieved in pilot-scale biofilm sequencing batch reactor (BSBR) with a low carbon source (C) cost. Especially, a high-abundance glycogen-accumulating organisms (GAOs) (13.93-31.72%) was detected that was accompanied by a high P recovery concentration of BSBR. High-abundance GAOs obtain additional C through various C compensation pathways (split tricarboxylic acid cycle (TCA cycle), glyoxylate shunt and gluconeogenesis), thus reducing the need to compete with polyphosphate-accumulating organisms (PAOs) for C and weakening the adverse effects on P recovery by PAO cells. Under the action of N-acyl homoserine lactones (AHLs)-mediated quorum sensing (QS), GAOs promoted the secretion of a large amount of extracellular polymeric substances (EPS), which helped to realize the P recovery of EPS-dominated biofilms (68.02%-96.89%). This study provides a low-carbon technology for the recovery of high concentration P from municipal wastewater, and improves the ecological theory of P recovery in collaboration with GAOs and PAOs.},
}

@article {pmid39615759,
year = {2024},
author = {Zhang, H and Zhang, J and Fan, S and Lu, J and Zhang, W and Ding, W},
title = {Synthetic biofilm community for efficient phosphorus removal from high-salinity wastewater.},
journal = {Bioresource technology},
volume = {418},
number = {},
pages = {131902},
doi = {10.1016/j.biortech.2024.131902},
pmid = {39615759},
issn = {1873-2976},
abstract = {Substantial amounts of phosphorus are discharged into water bodies, leading to an urgent need to develop methods for phosphorus removal. Here, 12 novel polyphosphate-accumulating organisms were identified from marine biofilms through genomic screening and incorporated into a stable community for phosphorus removal from high-salinity water. The synthetic biofilm community achieved an 82% removal efficiency in a marine broth medium. Electron microscopy showed storage of polyphosphate particles in the bacterial cells. Metatranscriptomic analysis indicated expression changes of genes for phosphate transport, as well as relevant metabolic pathways. In particular, pst genes encoding transporters with high phosphate affinity were downregulated at high-phosphorus concentration, whereas pit genes encoding transporters with low phosphate affinity were constitutively expressed. Furthermore, the synthetic biofilm community exhibited remarkable efficiency in removing over 92% of phosphorus from fish farming facility wastewater. Taken together, synthetic community using marine biofilm bacteria is a new strategy of phosphorus removal.},
}

@article {pmid39615517,
year = {2024},
author = {Cordero García-Galán, E and Medel-Plaza, M and Pozo-Kreilinger, JJ and Sarnago, H and Lucía, Ó and Rico-Nieto, A and Esteban, J and Gomez-Barrena, E},
title = {In vivo reduction of biofilm seeded on orthopaedic implants.},
journal = {Bone & joint research},
volume = {13},
number = {12},
pages = {695-702},
pmid = {39615517},
issn = {2046-3758},
support = {//Fundación Mutua Madrileña/ ; },
abstract = {AIMS: Electromagnetic induction heating has demonstrated in vitro antibacterial efficacy over biofilms on metallic biomaterials, although no in vivo studies have been published. Assessment of side effects, including thermal necrosis of adjacent tissue, would determine transferability into clinical practice. Our goal was to assess bone necrosis and antibacterial efficacy of induction heating on biofilm-infected implants in an in vivo setting.

METHODS: Titanium-aluminium-vanadium (Ti6Al4V) screws were implanted in medial condyle of New Zealand giant rabbit knee. Study intervention consisted of induction heating of the screw head up to 70°C for 3.5 minutes after implantation using a portable device. Both knees were implanted, and induction heating was applied unilaterally keeping contralateral knee as paired control. Sterile screws were implanted in six rabbits, while the other six received screws coated with Staphylococcus aureus biofilm. Sacrifice and sample collection were performed 24, 48, or 96 hours postoperatively. Retrieved screws were sonicated, and adhered bacteria were estimated via drop-plate. Width of bone necrosis in retrieved femora was assessed through microscopic examination. Analysis was performed using non-parametric tests with significance fixed at p ≤ 0.05.

RESULTS: The width of necrosis margin in induction heating-treated knees ranged from 0 to 650 μm in the sterile-screw group, and 0 to 517 μm in the biofilm-infected group. No significant differences were found between paired knees. In rabbits implanted with sterile screws, no bacteria were detected. In rabbits implanted with infected screws, a significant bacterial load reduction with median 0.75 Log10 colony-forming units/ml was observed (p = 0.016).

CONCLUSION: Induction heating was not associated with any demonstrable thermal bone necrosis in our rabbit knee model, and might reduce bacterial load in S. aureus biofilms on Ti6Al4V implants.},
}

@article {pmid39614912,
year = {2024},
author = {Petchimuthu, R and Sundar, K and Balakrishnan, V},
title = {Characterization, immobilization and evaluation of anti-Pseudomonas aeruginosa biofilm activity of alginate lyase from marine bacterium, Enterobacter tabaci RAU2C.},
journal = {Biotechnology letters},
volume = {47},
number = {1},
pages = {9},
pmid = {39614912},
issn = {1573-6776},
support = {KARE/VC/R&D/SMPG/2023-2024/01//Kalasalingam Academy of Research and Education/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Polysaccharide-Lyases/metabolism/pharmacology/chemistry ; *Pseudomonas aeruginosa/drug effects/physiology/enzymology ; *Enzymes, Immobilized/metabolism/chemistry/pharmacology ; *Enterobacter/drug effects/enzymology/physiology ; Hydrogen-Ion Concentration ; *Anti-Bacterial Agents/pharmacology ; Alginates/chemistry/pharmacology/metabolism ; Temperature ; Kinetics ; Enzyme Stability ; },
abstract = {Alginate lyases have the potential to be used as a therapeutic agent for P. aeruginosa infections. The present work was focused on the characterization of free and immobilized alginate lyase produced by marine bacteria, Enterobacter tabaci RAU2C isolated previously in the laboratory for alginate lyase production and exploring the potential of alginate lyase as an anti-biofilm agent against the P. aeruginosa biofilm. RAU2C alginate lyase was immobilized using an epoxy-activated curdlan matrix by three different methods. Further, the free and immobilized were characterized for its optimal pH and temperature. The effect of alginate concentration on alginate lyase activity was assessed and the kinetic parameters were evaluated. The anti-biofilm activity of the crude alginate lyase was studied using biofilm inhibition and disruption assays in microtiter plates with crystal violet. The biofilm disruption by RAU2C alginate lyase was also ascertained by microscopic analysis. The immobilization matrix prepared using method 3 had a better binding capacity compared to other methods. Both soluble and immobilized alginate lyase exhibited optimal activity at 37 °C and pH 7.0. Km and Vmax of soluble and immobilized alginate lyase were found to be 3.38 mg/mL, 22.98 mg/mL min and 3.67 mg/mL and 26.59 mg/mL min respectively. Both microtiter assay and microscopic analysis confirmed the prevention and dispersal of pre-existing biofilms by crude RAU2C alginate lyase, highlighting its potential as an anti-biofilm agent against P. aeruginosa. The study highlights the efficacy of RAU2C alginate lyase as an anti-biofilm agent in controlling P. aeruginosa biofilms.},
}

*Biofilms/drug effects/growth & development
*Polysaccharide-Lyases/metabolism/pharmacology/chemistry
*Pseudomonas aeruginosa/drug effects/physiology/enzymology
*Enzymes, Immobilized/metabolism/chemistry/pharmacology
*Enterobacter/drug effects/enzymology/physiology
Hydrogen-Ion Concentration
*Anti-Bacterial Agents/pharmacology
Alginates/chemistry/pharmacology/metabolism
Temperature
Kinetics
Enzyme Stability

@article {pmid39614893,
year = {2024},
author = {Nath, R and Lahiri, D and Nag, M and Mahapatra, D and Bhattacharya, M and Dutta, K and Bhattacharya, D},
title = {Antibiofilm activity of exopolysaccharide-mediated ZnO nanoparticle against Pseudomonas aeruginosa biofilm.},
journal = {Naunyn-Schmiedeberg's archives of pharmacology},
volume = {},
number = {},
pages = {},
pmid = {39614893},
issn = {1432-1912},
abstract = {Exopolysaccharides (EPSs) are the group of biological macromolecules those play a potent role in protecting the bacteria from any sorts of stress. They exhibit multifunctional roles in natural and bioactive product science hence exhibits various types of medical and biochemical applications. EPS ensures the storage of nutrients, produce antigens to create defense mechanism during infection, and is also responsible for the formation of biofilm and cell adhesion. Green synthesis of ZnO nanoparticle mediated by EPS from Lactobacillus sp. which is a type of lactic acid bacteria (LAB) is a novel approach for its application in the food industry as it exhibits antimicrobial and antibiofilm potential. In this study, Lactobacillus sp. was cultivated in Lactobacillus broth media (LBM) and glucose mineral salt media (GMSM) to identify the best suitable media that would provide maximum amount of EPS, and it was observed that the two media exhibited maximum yield of 0.8 g/L and 0.6 g/L respectively after 48-h incubation. SEM, EDS, and XRD were used for characterizing the green synthesized ZnONPs from the EPS and was observed that the NPs were synthesized. 62.6% and 67.6% ZnONPs were observed in LBM-ZnONP and GMSM-ZnONP respectively from XRD analysis. UV spectroscopic detection showed corresponding peak of the nanoparticle formed at 349 nm which confirmed the production of ZnO NPs. Scanning electron microscopic (SEM) images and Fourier transform infrared spectroscopy (FT-IR) established the average size, shape, and composition of the nanoparticles. The peaks of the FT-IR also revealed the presence of the C = H and N-H stretching (1 H). It was also observed that the average size of LBM ZnONPs were 60.578 nm whereas GMSM ZnONPs were 53.09 nm. Viability studies exhibited that the NPs brought considerable reduction of the sessile cells of P. aeuginosa. It was further observed that the cells treated with NPs did not show revival. The NPs were able to inhibit the quorum sensing (QS) mechanism of Pseudomonas aeruginosa thereby preventing the development of virulence. Out of the two NPs, it was observed that GMSM ZnONPs showed better efficacy in comparison to LBM ZnONPs. Thus, the study concludes that EPS-mediated NPs can be used effectively in the process of treating the biofilm.},
}

@article {pmid39614781,
year = {2024},
author = {Janež, N and Ladányi, M and Sterniša, M and Jug, B and Zupan, T and Peternel, T and Sebastijanović, A and Perišić Nanut, M and Karničar, K and Taler-Verčič, A and Turk, D and Klančnik, A and Štrancar, J and Sabotič, J},
title = {Exposure to specific fungal lectins during adhesion impairs biofilm formation of Listeria on polystyrene.},
journal = {Microbial biotechnology},
volume = {17},
number = {12},
pages = {e70040},
pmid = {39614781},
issn = {1751-7915},
support = {J2-50064//Javna Agencija za Raziskovalno Dejavnost RS/ ; J4-1771//Javna Agencija za Raziskovalno Dejavnost RS/ ; J4-2543//Javna Agencija za Raziskovalno Dejavnost RS/ ; J4-4555//Javna Agencija za Raziskovalno Dejavnost RS/ ; P4-0116//Javna Agencija za Raziskovalno Dejavnost RS/ ; P4-0127//Javna Agencija za Raziskovalno Dejavnost RS/ ; P4-0432//Javna Agencija za Raziskovalno Dejavnost RS/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Listeria/drug effects/physiology/growth & development ; *Lectins/pharmacology/metabolism ; *Listeria monocytogenes/physiology/drug effects/growth & development ; *Bacterial Adhesion/drug effects ; *Polystyrenes ; Fungal Proteins/metabolism/genetics ; Microbial Viability/drug effects ; Fungi/physiology/drug effects ; Temperature ; Anti-Bacterial Agents/pharmacology ; },
abstract = {Listeria monocytogenes is a pathogenic bacterium that can form biofilms in food processing plants, allowing the bacteria to survive despite the control measures applied. As the surface of the bacteria is covered with versatile polysaccharides and proteins, these influence the interactions of the bacterium with any surface. The unique properties and high stability of fungal proteins make them good candidates for the control of bacteria by targeting surface structures. We screened a group of fungal lectins and protease inhibitors from different fungal species, protein folds and known targets for their antibacterial and antibiofilm activity against model strains of Listeria innocua and Listeria monocytogenes. Several of them significantly decreased the viability of biofilm bacteria, but had no effect on bacterial growth parameters at 37°C and thus had no antibacterial activity. Fungal lectins significantly impaired biofilm development even at room temperature, which was attributed to exposure to lectins during adhesion. The tested fungal proteins also reduced biofilm development on biological model surfaces. The observed antibiofilm activity of fungal proteins suggests that they have the potential to modulate interactions between bacteria and/or between bacteria and surfaces, which could be used in the future to reduce surface contamination by Listeria.},
}

*Biofilms/drug effects/growth & development
*Listeria/drug effects/physiology/growth & development
*Lectins/pharmacology/metabolism
*Listeria monocytogenes/physiology/drug effects/growth & development
*Bacterial Adhesion/drug effects
*Polystyrenes
Fungal Proteins/metabolism/genetics
Microbial Viability/drug effects
Fungi/physiology/drug effects
Temperature
Anti-Bacterial Agents/pharmacology

@article {pmid39612475,
year = {2024},
author = {Lopez, AE and Mayoral, J and Zheng, H and Cianciotto, NP},
title = {Legionella pneumophila IrsA, a novel, iron-regulated exoprotein that facilitates growth in low-iron conditions and modulates biofilm formation.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0231324},
doi = {10.1128/spectrum.02313-24},
pmid = {39612475},
issn = {2165-0497},
abstract = {To discover new factors that are involved in iron acquisition by Legionella pneumophila, we used RNA-Seq to identify the genes that are most highly induced when virulent strain 130b is cultured in a low-iron chemically defined medium. Among other things, this revealed 14915, a heretofore uncharacterized gene that is predicted to be transcriptionally regulated by Fur and to encode a novel, ~15 kDa protein. 14915 was present in all L. pneumophila strains examined and had homologs in a subset of the other Legionella species. Compatible with it containing a classic signal sequence, the 14915 protein was detected in bacterial culture supernatants in a manner dependent upon the L. pneumophila type II secretion system. Thus, we designated 14915 as IrsA for iron-regulated, secreted protein A. Based on mutant analysis, the irsA gene was not required for optimal growth of strain 130b in low-iron media. However, after discovering that the commonly used laboratory-derived strain Lp02 has a much greater requirement for iron, we uncovered a growth-enhancing role for IrsA after examining an Lp02 mutant that lacked both IrsA and the Fe[2+]-transporter FeoB. The irsA mutant of 130b, but not its complemented derivative, did, however, display increased biofilm formation on both plastic and agar surfaces, and compatible with this, the mutant hyper-aggregated. Thus, IrsA is a novel, iron-regulated exoprotein that modulates biofilm formation and, under some circumstances, promotes growth in low-iron conditions. For this study, we determined and deposited in the database a complete and fully assembled genome sequence for strain 130b.IMPORTANCEThe bacterium Legionella pneumophila is the principal cause of Legionnaires' disease, a potentially fatal form of pneumonia that is increasing in incidence. L. pneumophila exists in many natural and human-made water systems and can be transmitted to humans through inhalation of contaminated water droplets. L. pneumophila flourishes within its habitats by spreading planktonically, assembling into biofilms, and growing in larger host cells. Iron acquisition is a key determinant for L. pneumophila persistence in water and during infection. We previously demonstrated that L. pneumophila assimilates iron both by secreting a non-protein iron chelator (siderophore) and by importing iron through membrane transporters. In this study, we uncovered a novel, secreted protein that is highly iron-regulated, promotes L. pneumophila's growth in low-iron media, and impacts biofilm formation. We also identified uncharacterized, IrsA-related proteins in other important human and animal pathogens. Thus, our results have important implications for understanding iron assimilation, biofilm formation, and pathogenesis.},
}

@article {pmid39612218,
year = {2024},
author = {De Bleeckere, A and van Charante, F and Debord, T and Vandendriessche, S and De Cock, M and Verstraete, M and Lamret, F and Lories, B and Boelens, J and Reffuveille, F and Steenackers, HP and Coenye, T},
title = {A novel synthetic synovial fluid model for investigating biofilm formation and antibiotic susceptibility in prosthetic joint infections.},
journal = {Microbiology spectrum},
volume = {},
number = {},
pages = {e0198024},
doi = {10.1128/spectrum.01980-24},
pmid = {39612218},
issn = {2165-0497},
abstract = {UNLABELLED: There is growing evidence that bacteria encountered in prosthetic joint infections (PJIs) form surface-attached biofilms on prostheses, as well as biofilm aggregates embedded in synovial fluid and tissues. However, in vitro models allowing the investigation of these biofilms and the assessment of their antimicrobial susceptibility in physiologically relevant conditions are currently lacking. To address this, we developed a synthetic synovial fluid (SSF2) model and validated this model by investigating growth, aggregate formation, and antimicrobial susceptibility using multiple PJI isolates belonging to various microorganisms. In this study, 18 PJI isolates were included belonging to Staphylococcus aureus, coagulase-negative staphylococci, Cutibacterium acnes, Streptococcus spp., Enterococcus spp., Pseudomonas aeruginosa, Escherichia coli, and Candida spp. Growth and aggregate formation in SSF2 were evaluated using light microscopy and confocal laser scanning microscopy. The biofilm preventing concentration (BPC) and minimal biofilm inhibitory concentration (MBIC) of relevant antibiotics were determined using a resazurin-based viability staining. BPC and MBIC values were compared to conventional susceptibility parameters (minimal inhibitory concentration and minimal bactericidal concentration) determined with conventional approaches. The SSF2 medium allowed isolates to grow and form biofilm-like aggregates varying in size and shape between different species. For most isolates cultured in SSF2, a reduced susceptibility to the tested antibiotics was observed when compared to susceptibility data obtained in general media. These data indicate that the in vitro SSF2 model could be a valuable addition to evaluate the antimicrobial susceptibility of biofilm-like aggregates in the context of PJI.

IMPORTANCE: Infections after joint replacement are rare but can lead to severe complications as they are difficult to treat due to the ability of pathogens to form surface-attached biofilms on the prosthesis as well as biofilm aggregates in the tissue and synovial fluid. This biofilm phenotype, combined with the microenvironment at the infection site, substantially increases antimicrobial tolerance. Conventional in vitro models typically use standard growth media, which do not consider the microenvironment at the site of infection. By replacing these standard growth media with an in vivo-like medium, such as the synthetic synovial fluid medium, we hope to expand our knowledge on the aggregation of pathogens in the context of PJI. In addition, we believe that inclusion of in vivo-like media in antimicrobial susceptibility testing might be able to more accurately predict the in vivo susceptibility, which could ultimately result in a better clinical outcome after antimicrobial treatment.},
}

@article {pmid39611239,
year = {2024},
author = {Wyatt, KH and Cieslik, J and Dieleman, CM and Kane, ES and Rober, AR and Sullivan, B and Turetsky, MR},
title = {Legacy Effects of Plant Community Structure Are Manifested in Microbial Biofilm Development With Consequences for Ecosystem CO2 Emissions.},
journal = {Global change biology},
volume = {30},
number = {12},
pages = {e17603},
pmid = {39611239},
issn = {1365-2486},
support = {1636476//Division of Environmental Biology/ ; 2011257//Division of Environmental Biology/ ; 2011286//Division of Environmental Biology/ ; 2141285//Division of Environmental Biology/ ; RJVA-PNW-01-JV-11261952-231//Pacific Northwest Research Station/ ; },
mesh = {*Carbon Dioxide/analysis/metabolism ; *Biofilms/growth & development ; *Ecosystem ; Carbon Cycle ; Plants/microbiology ; Seasons ; Autotrophic Processes ; Groundwater/microbiology/chemistry ; Hydrology ; },
abstract = {To better understand linkages between hydrology and ecosystem carbon flux in northern aquatic ecosystems, we evaluated the relationship between plant communities, biofilm development, and carbon dioxide (CO2) exchange following long-term changes in hydrology in an Alaskan fen. We quantified seasonal variation in biofilm composition and CO2 exchange in response to lowered and raised water table position (relative to a control) during years with varying levels of background dissolved organic carbon (DOC). We then used nutrient-diffusing substrates (NDS) to evaluate cause-effect relationships between changes in plant subsidies (i.e., leachates) and biofilm composition among water table treatments. We found that background DOC concentration determined whether plant subsidies promoted net autotrophy or heterotrophy on NDS. In conditions where background DOC was ≤ 40 mg L[-1], plant subsidies promoted an autotrophic biofilm. Conversely, when background DOC concentration was ≥ 50 mg L[-1], plant subsidies promoted heterotrophy. Greater light attenuation associated with elevated levels of DOC may have overwhelmed the stimulatory effect of nutrients on autotrophic microbes by constraining photosynthesis while simultaneously allowing heterotrophs to outcompete autotrophs for available nutrients. At the ecosystem level, conditions that favored an autotrophic biofilm resulted in net CO2 uptake among all water table treatments, whereas the site was a net source of CO2 to the atmosphere in conditions that supported greater heterotrophy. Taken together, these findings show that hydrologic history interacts with changes in dominant plant functional groups to alter biofilm composition, which has consequences for ecosystem CO2 exchange.},
}

*Carbon Dioxide/analysis/metabolism
*Biofilms/growth & development
*Ecosystem
Carbon Cycle
Plants/microbiology
Seasons
Autotrophic Processes
Groundwater/microbiology/chemistry
Hydrology

@article {pmid39610831,
year = {2024},
author = {Willett, MR and Codd, SL and Seymour, JD and Kirkland, CM},
title = {Relaxation-weighted MRI analysis of biofilm EPS: Differentiating biopolymers, cells, and water.},
journal = {Biofilm},
volume = {8},
number = {},
pages = {100235},
pmid = {39610831},
issn = {2590-2075},
abstract = {Biofilms are a highly complex community of microorganisms embedded in a protective extracellular polymeric substance (EPS). Successful biofilm control requires a variety of approaches to better understand the structure-function relationship of the EPS matrix. Magnetic resonance imaging (MRI) is a versatile tool which can measure spatial structure, diffusion, and flow velocities in three dimensions and in situ. It is well-suited to characterize biofilms under natural conditions and at different length scales. MRI contrast is dictated by T 1 and T 2 relaxation times which vary spatially depending on the local chemical and physical environment of the sample. Previous studies have demonstrated that MRI can provide important insights into the internal structure of biofilms, but the contribution of major biofilm components-such as proteins, polysaccharides, and cells-to MRI contrast is not fully understood. This study explores how these components affect contrast in T 1 -and T 2 -weighted MRI by analyzing artificial biofilms with well-defined properties modeled after aerobic granular sludge (AGS), compact spherical biofilm aggregates used in wastewater treatment. MRI of these biofilm models showed that certain gel-forming polysaccharides are a major source of T 2 contrast, while other polysaccharides show minimal contrast. Proteins were found to reduce T 2 contrast slightly when combined with polysaccharides, while cells had a negligible impact on T 2 but showed T 1 contrast. Patterns observed in the model biofilms served as a reference for examining T 2 and T 1 -weighted contrast in the void spaces of two distinct AGS granules, allowing for a qualitative evaluation of the EPS components which may be present. Further insights provided by MRI may help improve understanding of the biofilm matrix and guide how to better manage biofilms in wastewater, clinical, and industrial settings.},
}

@article {pmid39610010,
year = {2024},
author = {Bertl, K and Al-Said, M and Mourad, A and Mayol, M and Lopes da Silva, Z and Papia, E and Stavropoulos, A},
title = {Reduced Biofilm Accumulation on Implants Treated With Implantoplasty-An In Situ Trial With a Within-Subject Comparison.},
journal = {Clinical and experimental dental research},
volume = {10},
number = {6},
pages = {e70043},
pmid = {39610010},
issn = {2057-4347},
support = {//This study was funded by the authors' institutions./ ; },
mesh = {Humans ; *Biofilms ; Male ; Female ; *Dental Implants/microbiology ; Adult ; *Surface Properties ; Titanium ; Middle Aged ; Young Adult ; Dental Prosthesis Design ; },
abstract = {OBJECTIVES: This study aimed to evaluate potential differences in biofilm accumulation on three different implant surfaces: turned surface (TS), modified surface (MS), and modified surface treated with implantoplasty (IPS), using a within-subject comparison.

MATERIAL AND METHODS: Ten volunteers wore individualized splints containing three titanium implants with different surfaces (TS, MS, and IPS) on each buccal side of the splint. The implant position (anterior, central, and posterior) was randomly assigned among the three implants on each side. Volunteers were instructed to wear the splint for 72 h and to remove it only for eating, drinking, and performing standard oral hygiene; the splint itself was not cleaned. After 72 h, the implants were carefully removed from the splint, and the accumulated biofilm was assessed using a crystal violet assay by measuring intensity/absorbance at 570 nm.

RESULTS: All volunteers reported no deviations from the instructions. The lowest mean amount of biofilm (0.405 ± 0.07) was detected on implants of the IPS group, followed by implants of the MS (0.463 ± 0.06) and TS group (0.467 ± 0.07). A multilevel mixed-effects linear regression analysis confirmed that implants of the IPS group accumulated a significantly lower amount of biofilm than the other surfaces (p < 0.001); however, no significant difference was detected between implants of the TS and MS groups (p = 0.806).

CONCLUSIONS: Implantoplasty can generate a surface significantly less conducive to biofilm accumulation in the short term compared to pristine implants with turned or modified surfaces.

TRIAL REGISTRATION: clinicaltrials.gov identifier: NCT06049121.},
}

Humans
*Biofilms
Male
Female
*Dental Implants/microbiology
Adult
*Surface Properties
Titanium
Middle Aged
Young Adult
Dental Prosthesis Design

@article {pmid39609958,
year = {2024},
author = {Khursheed, H and Qasim, R},
title = {SYNERGISTIC ANTIBIOFILM ACTIVITY OF PROBIOTIC LACTOBACILLUS ACIDOPHILUS AND PUNICA GRANATUM L., AGAINST PSEUDOMONAS AERUGINOSA BIOFILM.},
journal = {Journal of Ayub Medical College, Abbottabad : JAMC},
volume = {36},
number = {2},
pages = {245-250},
doi = {10.55519/JAMC-02-12876},
pmid = {39609958},
issn = {1819-2718},
mesh = {*Biofilms/drug effects ; *Pseudomonas aeruginosa/drug effects ; *Lactobacillus acidophilus/drug effects/physiology ; *Pomegranate ; *Probiotics ; *Plant Extracts/pharmacology ; Humans ; Drug Synergism ; },
abstract = {BACKGROUND: Antibiotic resistance is one of the most urgent public health concerns. Biofilm formation is well linked with chronic wounds, chronic obstructive pulmonary disease, urinary tract infections, and cystic fibrosis. Our goal was to assess the biofilm activity of P. aeruginosa and the individual and combined anti-biofilm forming activity of probiotic Lactobacillus acidophilus and Pomegranate peel extract Punica granatum L., against P. aeruginosa.

METHODS: A total of 150 swabs of urine, blood, pus, and CSF were collected from PNS Shifa Hospital Karachi, and P. aeruginosa was isolated and identified according to standard bacteriological methods. The ability of P. aeruginosa to form biofilms was assessed using a microtiter plate assay.

RESULTS: The anti-biofilm forming activity of pomegranate peels extract against P. aeruginosa was 29.26±19.09 whereas the anti-biofilm forming activity of Lactobacillus acidophilus against P. aeruginosa was 0.5×106. When used in combination, there was significant synergistic activity between Punica granatum L. (pomegranate peel extract) and Lactobacillus acidophilus.

CONCLUSIONS: The unique synergistic mixture of natural product extracts and probiotics has demonstrated more efficiency against rapidly evolving pathogens, serving as promising candidates for developing biofilm inhibitors and perhaps proving as possible environmentally friendly agents against bacteria that produce antibiotic-resistant biofilms.},
}

*Biofilms/drug effects
*Pseudomonas aeruginosa/drug effects
*Lactobacillus acidophilus/drug effects/physiology
*Pomegranate
*Probiotics
*Plant Extracts/pharmacology
Humans
Drug Synergism

@article {pmid39609837,
year = {2024},
author = {Zhang, HL and Wang, HW and Yang, JH and Chen, JJ and Liu, J and Shi, QC and Zhao, HC and Chen, MX and Yang, R and Ji, QT and Wang, PY},
title = {From dansyl-modified biofilm disruptors to β-cyclodextrin-optimized multifunctional supramolecular nanovesicles: their improved treatment for plant bacterial diseases.},
journal = {Journal of nanobiotechnology},
volume = {22},
number = {1},
pages = {739},
pmid = {39609837},
issn = {1477-3155},
support = {2022YFD1700300//National Key Research and Development Program/ ; No. GCC[2023]008//Innovation Program for High-level Talents of Guizhou Province/ ; ZK[2022]017//Guizhou Provincial S&T Project/ ; Guidakechuangtuan[2023]03//Research and Innovation Team of Guizhou University/ ; Guidazhuanjihe[2024]02//Natural Science Special Project of Guizhou University/ ; Qiankehezhongyindi (2023) 001//Central Government Guides Local Science and Technology Development Fund Projects/ ; 111 Program, D20023//Program of Introducing Talents of Discipline to Universities of China/ ; },
mesh = {*Biofilms/drug effects ; *Plant Diseases/microbiology/prevention & control ; *beta-Cyclodextrins/chemistry ; *Xanthomonas/drug effects ; Anti-Bacterial Agents/pharmacology/chemistry ; Dansyl Compounds/chemistry/pharmacology ; Nanoparticles/chemistry ; Citrus/chemistry ; },
abstract = {BACKGROUND: Bacterial diseases caused by phytopathogenic Xanthomonas pose a significant threat to global agricultural production, causing substantial economic losses. Biofilm formation by these bacteria enhances their resistance to environmental stressors and chemical treatments, complicating disease control. The key to overcoming this challenge lies in the development of multifunctional green bactericides capable of effectively breaking down biofilm barriers, improving foliar deposition properties, and achieving the control of bacterial diseases.

RESULTS: We have developed a kind of innovative green bactericide from small-molecule conception to eco-friendly supramolecular nanovesicles (DaPA8@β -CD) by host-guest supramolecular technology. These nanoscale assemblies demonstrated the ability to inhibit and eradicate biofilm formation, while also promoted foliar wetting and effective deposition properties, laying the foundation for improving agrochemical utilization. Studies revealed that DaPA8@β -CD exhibited significant biofilm inhibition (78.66% at 7.0 µ g mL[- 1]) and eradication (83.50% at 25.0 µ g mL[- 1]), outperforming DaPA8 alone (inhibition: 59.71%, eradication: 66.79%). These nanovesicles also reduced exopolysaccharide formation and bacterial virulence. In vivo experiments showed enhanced control efficiency against citrus bacterial canker (protective: 78.04%, curative: 50.80%) at a low dose of 200 µ g mL[- 1], superior to thiodiazole-copper-20%SC and DaPA8 itself.

CONCLUSION: This study demonstrates the potential of DaPA8@β -CD nanovesicles as multifunctional bactericides for managing Xanthomonas -induced plant diseases, highlighting the advantages of using host-guest supramolecular technology to enhance agrochemical bioavailability.},
}

*Biofilms/drug effects
*Plant Diseases/microbiology/prevention & control
*beta-Cyclodextrins/chemistry
*Xanthomonas/drug effects
Anti-Bacterial Agents/pharmacology/chemistry
Dansyl Compounds/chemistry/pharmacology
Nanoparticles/chemistry
Citrus/chemistry

@article {pmid39608581,
year = {2024},
author = {Werneburg, GT and Vasavada, SP and Miller, AW},
title = {Reply to Editorial Comment on "Indwelling urological device biofilm composition and characteristics in the presence and absence of infection.},
journal = {Urology},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.urology.2024.11.049},
pmid = {39608581},
issn = {1527-9995},
}

@article {pmid39608508,
year = {2024},
author = {Xu, S and Feng, Y and Li, H and Huang, H and Chen, Q and Zhu, B and Liu, A and Xu, Y and Jin, X and Gui, S and Lu, X},
title = {Natural TPs inhibit biofilm formation by Multidrug-resistant Acinetobacter baumannii and biofilm-induced pulmonary inflammation.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107172},
doi = {10.1016/j.micpath.2024.107172},
pmid = {39608508},
issn = {1096-1208},
abstract = {Multidrug-resistant Acinetobacter baumannii (MDRAB) infections cause elevated rates of patient deaths in intensive care units owing to the high antibiotic resistance of the clinical isolates. The advent of multidrug-resistant A. baumannii (MDRAB) strains and the formation of their biofilms are cause for concern. Tea polyphenols (TPs), which exhibit antimicrobial activity, is an ideal alternative strategy for lowering the incidence of nosocomial bacterial infections. This study was conducted to determine the effects of TPs on MDRAB. The antimicrobial and anti-biofilm activities of TPs against MDRAB were investigated in vitro using the propidium iodide assay, scanning electron microscopy, transmission electron microscopy, crystalline violet staining and real-time quantitative PCR (qPCR). The in vivo anti-biofilm and anti-inflammatory effects of TPs were studied using a rat model of MDRAB biofilm-induced pulmonary inflammation. TPs effectively inhibited the proliferation of MDRAB and damaged its cell membrane. Additionally, they inhibited MDRAB biofilm formation by reducing the content of microbial extracellular polymeric substances and altering the expression of genes related to biofilm formation. Moreover, TPs reduced pathological features of lung injury and alleviated MDRAB biofilm-induced pneumonia in rats with a tracheal cannula, attenuating the inflammatory response by inhibiting NF-κB signaling. Our findings suggest that the anti-biofilm and anti-inflammatory activities of TPs render these naturally active compounds favorable candidates for the treatment of tracheal catheter-related infections.},
}

@article {pmid39608432,
year = {2024},
author = {Wang, B and Ma, P and Liu, M and Huang, R and Qiu, Z and Pan, L and Wang, J and Liu, Y and Zhang, Q},
title = {Enhancement of microalgae co-cultivation culture on self-settling performance and water purification capacity of microalgae biofilm.},
journal = {Environmental research},
volume = {},
number = {},
pages = {120342},
doi = {10.1016/j.envres.2024.120342},
pmid = {39608432},
issn = {1096-0953},
abstract = {Cultivating microalgae for the remediation of aquaculture wastewater provides a promising solution for pollution control. However, the economic viability of this approach faces challenges due to the high costs associated with microalgal biomass harvesting. This study aims to address this issue by immobilizing microalgae onto coral velvet carriers, enhancing the efficiency of biomass recovery. Four types of microalgae were screened: Chlorella sp., Isochrysis galbana, Chaetoceros sp., and Nannochloropsis sp. Among them, Isochrysis galbana exhibited the best self sedimentation rate, achieving a self sedimentation rate of 94.36%. Chlorella sp. demonstrated the best denitrification rate, with a nitrate removal rate of 100% and an inorganic nitrogen removal rate of 79.13%. In addition, this study found that extracellular polymeric substances(EPS) affects the self-settling performance of microalgae, and the results emphasize the key role of tightly-bound EPS(TB-EPS) content in determining self settling efficiency. Furthermore,the assessments of the purification of simulated aquaculture wastewater were conducted, comparing the outcomes of co-cultivation with mono-culture. The co-cultivation strategy showed exceptional efficacy, achieving a 100% removal rate for NO3[-]-N by the 5th day. In contrast, mono-cultures of Chlorella sp. and Isochrysis galbana showed removal rates of 77.76% and 45.72%, respectively, at the same interval. Applying of the co-cultivation microalgal biofilm to treat the actual aquaculture wastewater showed remarkable denitrification performance, attaining a 100% removal rate for NO3[-]-N by the 7th day. The study proposes the co-cultivation of Chlorella sp. and Isochrysis galbana for treating aquaculture wastewater and explores the potential application of immobilization technology to remove nitrogen-containing pollutants.},
}

@article {pmid39606745,
year = {2024},
author = {Muturi, P and Wachira, P and Wagacha, M and Mbae, C and Kavai, SM and Mugo, MM and Mohamed, M and González, JF and Kariuki, S and Gunn, JS},
title = {Salmonella Typhi Haplotype 58 biofilm formation and genetic variation in isolates from typhoid fever patients with gallstones in an endemic setting in Kenya.},
journal = {Frontiers in cellular and infection microbiology},
volume = {14},
number = {},
pages = {1468866},
pmid = {39606745},
issn = {2235-2988},
mesh = {*Salmonella typhi/genetics/isolation & purification/drug effects ; Humans ; *Biofilms/growth & development ; *Typhoid Fever/microbiology/epidemiology ; Kenya ; *Genetic Variation ; *Gallstones/microbiology/complications ; Haplotypes ; Whole Genome Sequencing ; Anti-Bacterial Agents/pharmacology ; Genotype ; Feces/microbiology ; Male ; Endemic Diseases ; Female ; Adult ; Carrier State/microbiology ; },
abstract = {Although typhoid fever has largely been eliminated in high-income countries, it remains a major global public health concern especially among low- and middle-income countries. The causative agent, Salmonella enterica serovar Typhi (S. Typhi), is a human restricted pathogen with a limited capacity to replicate outside the human host. Human carriers, 90% of whom have gallstones in their gallbladder, continue to shed the pathogen for an ill-defined period of time after treatment. The genetic mechanisms involved in establishing the carrier state are poorly understood, but S. Typhi is thought to undergo specific genetic changes within the gallbladder as an adaptive mechanism. In the current study, we aimed to identify the genetic differences in longitudinal clinical S. Typhi isolates from asymptomatic carriers with gallstones in a typhoid endemic setting in Nairobi, Kenya. Whole-genome sequences were analyzed from 22 S. Typhi isolates, 20 from stool samples, and 2 from blood samples, all genotype 4.3.1 (H58). Out of this, 19 strains were from four patients also diagnosed with gallstones, of whom three had typhoid symptoms and continued to shed S. Typhi after treatment. All isolates had point mutations in the quinolone resistance-determining region (QRDR), and only sub-lineage 4.3.1.2.EA3 encoded multidrug resistance genes. There was no variation in antimicrobial resistance patterns among strains from the same patient/household. Non-multidrug resistant (MDR) isolates formed significantly stronger biofilms in vitro than the MDR isolates, p<0.001. A point mutation within the treB gene (treB A383T) was observed in strains isolated after clinical resolution from patients living in 75% of the households. For missense mutations in Vi capsular polysaccharide genes, tviE P263S was also observed in 18% of the isolates. This study provides insights into the role of typhoid carriage, biofilm formation, AMR genes, and genetic variations in S. Typhi during asymptomatic carriage.},
}

*Salmonella typhi/genetics/isolation & purification/drug effects
Humans
*Biofilms/growth & development
*Typhoid Fever/microbiology/epidemiology
Kenya
*Genetic Variation
*Gallstones/microbiology/complications
Haplotypes
Whole Genome Sequencing
Anti-Bacterial Agents/pharmacology
Genotype
Feces/microbiology
Male
Endemic Diseases
Female
Adult
Carrier State/microbiology

@article {pmid39605964,
year = {2024},
author = {Jia, J and Liu, Q and Zhao, E and Li, X and Xiong, X and Wu, C},
title = {Biofilm formation on microplastics and interactions with antibiotics, antibiotic resistance genes and pathogens in aquatic environment.},
journal = {Eco-Environment & Health},
volume = {3},
number = {4},
pages = {516-528},
pmid = {39605964},
issn = {2772-9850},
abstract = {Microplastics (MPs) in aquatic environments easily support biofilm development, which can interact with other environmental pollutants and act as harbors for microorganisms. Recently, numerous studies have investigated the fate and behavior of MP biofilms in aquatic environments, highlighting their roles in the spread of pathogens and antibiotic resistance genes (ARGs) to aquatic organisms and new habitats. The prevalence and effects of MP biofilms in aquatic environments have been extensively investigated in recent decades, and their behaviors in aquatic environments need to be synthesized systematically with updated information. This review aims to reveal the development of MP biofilm and its interactions with antibiotics, ARGs, and pathogens in aquatic environments. Recent research has shown that the adsorption capabilities of MPs to antibiotics are enhanced after the biofilm formation, and the adsorption of biofilms to antibiotics is biased towards chemisorption. ARGs and microorganisms, especially pathogens, are selectively enriched in biofilms and significantly different from those in surrounding waters. MP biofilm promotes the propagation of ARGs through horizontal gene transfer (HGT) and vertical gene transfer (VGT) and induces the emergence of antibiotic-resistant pathogens, resulting in increased threats to aquatic ecosystems and human health. Some future research needs and strategies in this review are also proposed to better understand the antibiotic resistance induced by MP biofilms in aquatic environments.},
}

@article {pmid39604799,
year = {2024},
author = {Li, B and Xu, Z and Wang, R and Nie, R and Tao, Z and Huang, X},
title = {Mineralizing Biofilm towards Sustainable Conversion of Plastic Wastes to Hydrogen.},
journal = {Angewandte Chemie (International ed. in English)},
volume = {},
number = {},
pages = {e202416577},
doi = {10.1002/anie.202416577},
pmid = {39604799},
issn = {1521-3773},
abstract = {The integration of inorganic materials with biological machinery to convert plastics into fuels offers a promising strategy to alleviate environmental pollution and energy crisis. Herein, we develop a type of hybrid living material via biomineralization of CdS onto Shewanella oneidensis-based biofilm, which is capable of sustainable hydrogen production from poly(lactic acid) (PLA) wastes under daylight. We reveal that the formed biofilm microstructure provides an independent anaerobic microenvironment that simultaneously supports cellular viability, maintains hydrogenase activity, and preserves the functional stability of CdS, giving rise to the efficient plastic-to-hydrogen conversion efficiency as high as 3751 μmol H2 g-1 PLA. Besides, by genetically engineering transmembrane pili conduit and incorporating conductive nanomaterials to strengthen the electron transfer across cellular interface and biofilm matrices, we show that the conversion efficiency is further enhanced to 5862 μmol H2 g-1 PLA. Significantly, we exhibit that a long-term sustainable plastic-to-hydrogen conversion of 63 d could be achieved by periodically replenishing PLA wastes. Overall, by the synergistic integration of biotic-abiotic characteristics the developed biofilm-based biomineralized hybrid living material is anticipated to provide a new platform toward the efficient conversion of plastic wastes into valuable fuels, and bridge the gap between environmental contamination and green energy production.},
}

@article {pmid39604718,
year = {2024},
author = {de Oliveira, RS and Gonçalves, AR and Ajulo, AA and Oliveira, LR and Lanna, AC and de Filippi, MCC},
title = {Survey and genomic characterization of Serratia marcescens on endophytism, biofilm, and phosphorus solubilization in rice plants.},
journal = {Environmental science and pollution research international},
volume = {},
number = {},
pages = {},
pmid = {39604718},
issn = {1614-7499},
support = {20.19.03.012.00.00//Empresa Brasileira de Pesquisa Agropecuária/ ; },
abstract = {Serratia marcescens, isolated from the rhizosphere of rice crops, has the potential to improve the acquisition of scarce minerals and provide plant growth. Rice seeds microbiolized with S. marcescens and non-microbiolized seeds were sown in a culture medium enriched with non-labile phosphorus, and the roots were analyzed in WinRhizo. The plant segments were documented by scanning electron microscopy (SEM) and incubated in an NBRIP culture medium. DNAs from endophytic colonies were extracted and analyzed by PCR. The genome of S. marcescens was annotated using subsystem technology to detect genes involved in phosphorus solubilization, biofilm production, and growth promotion. The root system increased in area, volume, and length by 61.5, 31.5, and 101%, respectively. Halos were formed around segments of microbiolized plants, indicating the solubilization of non-labile phosphorus. SEM detected the presence of biofilms and microcolonies, identified as S. marcescens by the molecular markers. Genome annotation found genes with potential functions in plant growth promotion, including genes involved in the biosynthesis of indole-3-acetic acid, phosphate solubilization, and biofilm production. In the low phosphorus crop, the treated plants showed a 181% increase in total biomass. S. marcescens solubilizes non-labile phosphorus, colonizes endophytes, modifies the architecture of the root system, and promotes the growth of rice plants, and can be considered a biofertilizer for growing upland rice.},
}

@article {pmid39604369,
year = {2024},
author = {Li, M and Zeng, Z and Wang, X and Liu, Y and Wei, H and Liu, J and Zhu, S and Jiang, Q and Zhang, K and Wu, Y and Liu, S and Kim, J and Liao, Q and Zhang, L},
title = {Mechanisms of S. agalactiae promoting G. vaginalis biofilm formation leading to recurrence of BV.},
journal = {NPJ biofilms and microbiomes},
volume = {10},
number = {1},
pages = {138},
pmid = {39604369},
issn = {2055-5008},
support = {61927819//National Natural Science Foundation of China (National Science Foundation of China)/ ; },
mesh = {*Biofilms/growth & development ; *Streptococcus agalactiae/genetics/physiology ; *Carbon-Sulfur Lyases/genetics/metabolism ; Humans ; *Bacterial Proteins/genetics/metabolism ; *Coculture Techniques ; Female ; *Gardnerella vaginalis/genetics/physiology ; *Vaginosis, Bacterial/microbiology ; *Homoserine/analogs & derivatives/metabolism ; Recurrence ; Lactones/metabolism ; Gene Expression Regulation, Bacterial ; Microbial Interactions ; },
abstract = {Previous research has established that the formation of Gardnerella vaginalis (GV) biofilm is one of the primary reasons for bacterial vaginosis (BV) recurrence. This study was the first to explore the impact of Streptococcus agalactiae (group B Streptococcus, GBS) on GV biofilm in a co-culture scenario. The results revealed that GBS could significantly increased the GV biomass in 48-hours dual-species biofilms. The luxS gene of GBS was significantly higher in dual-species biofilm, while knockdown of the luxS gene resulted in a significant decrease in mono- and dual-species biofilms. Meanwhile, in vitro addition of AI-2 (product of luxS gene) substantially increased biofilm biomass. Furthermore, we found that the expression of two genes related to biofilm formation was notably elevated in GV after receiving AI-2 signals. Collectively, these findings suggest that GBS enhances GV biofilm formation via luxS/AI-2 in an in vitro co-culture model, which in turn may promotes recurrence of BV.},
}

*Biofilms/growth & development
*Streptococcus agalactiae/genetics/physiology
*Carbon-Sulfur Lyases/genetics/metabolism
Humans
*Bacterial Proteins/genetics/metabolism
*Coculture Techniques
Female
*Gardnerella vaginalis/genetics/physiology
*Vaginosis, Bacterial/microbiology
*Homoserine/analogs & derivatives/metabolism
Recurrence
Lactones/metabolism
Gene Expression Regulation, Bacterial
Microbial Interactions

@article {pmid39603219,
year = {2024},
author = {Ijzerman, MM and Raby, M and Letwin, NV and Black, T and Kudla, YM and Osborne, RK and Sibley, PK and Prosser, RS},
title = {Pesticide presence in stream water, suspended sediment and biofilm is strongly linked to upstream catchment land use and crop type.},
journal = {Ecotoxicology and environmental safety},
volume = {288},
number = {},
pages = {117382},
doi = {10.1016/j.ecoenv.2024.117382},
pmid = {39603219},
issn = {1090-2414},
abstract = {Pesticide pollution can present high ecological risks to aquatic ecosystems. Small streams are particularly susceptible. There is a need for reproducible and readily available methods to identify aquatic regions at risk of pesticide contamination. There is currently a limited understanding of the relationship between upstream catchment land use and the presence of pesticides in multiple aquatic matrices. The aim of this study was to develop empirical relationships between different land uses and the levels of pesticides detected in multiple aquatic matrices. The inclusion of biofilm and suspended sediment as monitoring matrices has recently been proven effective for the characterization of pesticide exposure in stream ecosystems. Ten streams in Ontario, Canada with a variety of upstream catchment land uses were sampled in 2021 and 2022. Water, suspended sediment and biofilm were collected and analyzed from each site for the presence of approximately 500 different pesticides. Each of the three matrices exhibited distinctive pesticide exposure profiles. We found a significant relationship between the percentage of agriculture and urban land use and the detection of multiple pesticides in water, sediment and biofilm (logistic regressions, P<0.05). Statistically significant probabilistic models capable of predicting pesticide detections based on upstream catchment land use were developed. High-resolution cover crop maps identified soybeans, corn and other agriculture (e.g., vegetables, berries, canola) as the key variables associated with individual pesticide detection frequencies in each of the three matrices (linear regressions, P<0.05). Soybean land use was also the strongest predictor of site-wide pesticide pollution. This modelling approach using upstream catchment land use variables has the potential to be a powerful tool to identify streams at risk of pesticide pollution.},
}

@article {pmid39602230,
year = {2024},
author = {Millot, M and Imbert, C and Pouget, C and Girardot, M and Mambu, L},
title = {Lichen and its Microbiome as an Untapped Source of Anti-biofilm Compounds.},
journal = {Chemistry & biodiversity},
volume = {},
number = {},
pages = {e202401557},
doi = {10.1002/cbdv.202401557},
pmid = {39602230},
issn = {1612-1880},
abstract = {Lichen substances have been firstly described in the 1870s and most of them have been evaluated for their activity on planktonic microorganisms (bacteria and fungi). More recently, microorganisms colonizing the lichen thallus have been isolated and identified giving access to a wild diversity of culturable microorganisms. The increasing research in lichens associated microbiome in recent years, has emphased a wide range of metabolites as a potential source of bioactive compounds. In parallel, humans are facing microbial resistance to conventional antimicrobial drugs. One of the reasons is the biofilm lifestyle of microorganisms. Indeed, the aggregation of microbial communities inside biofilms is now well-known and characterized and some possible ways to fight and destroy biofilms are identified (quorum sensing inhibitors,…). The present review aims to summarize the anti-biofilm potential of lichen metabolites and those from their associated microorganisms (bacteria and/or fungi). Are the metabolites isolated from lichens and their associated fungi displaying any anti-biofilm activity? This literature synthesis highlights the metabolites of interest as new anti-biofilm drugs and shows the lack of current biological research dealing with biofilm and lichen metabolites. Only two lichen metabolites, usnic acid and evernic acid, have been evaluated both as antifungal and antibacterial biofilm compounds.},
}

@article {pmid39600574,
year = {2024},
author = {Gangwar, R and Salem, MM and Maurya, VK and Bekhit, MM and Singh, N and Amara, AAAF and Sahu, RK and Ibrahim, MA},
title = {Exploring time-killing and biofilm inhibition potential of bioactive proteins extracted from two varieties of Pleurotus ostreatus.},
journal = {Frontiers in microbiology},
volume = {15},
number = {},
pages = {1456358},
pmid = {39600574},
issn = {1664-302X},
abstract = {INTRODUCTION: Dental caries, caused by oral microbial pathogens, are a global health concern, further exacerbated by the presence of methicillin-resistant Staphylococcus aureus (MRSA). Bioactive proteins and peptides (BAPs) exhibit potent antimicrobial properties, targeting multiple cellular mechanisms within pathogens, reducing the likelihood of resistance development. Given the antimicrobial potential of BAPs, this study aimed to compare the efficacy of BAPs extracted from cultivated (Pleurotus ostreatus, PoC) and wild (Pleurotus ostreatus, PoW) mushrooms against pathogens responsible for dental caries.

METHODS: BAPs were extracted from both PoC and PoW using a TCA-acetone method. Antimicrobial activities were tested against seven bacteria and one fungus using agar well diffusion and MIC determination. Antibiofilm activity was assessed via modified CV assay, while DPPH and erythrocyte lysis tests evaluated free radical scavenging.

RESULTS: PoC showed superior antimicrobial efficacy, with lower MIC and MBC values, and disrupted biofilm integrity at increasing concentrations. PoW exhibited better antioxidant activity with higher DPPH scavenging, though its antimicrobial efficacy was slightly lower than PoC.

DISCUSSION: Both PoC and PoW BAPs inhibited dental pathogens, with PoC showing stronger inhibition against MRSA and nystatin-resistant Candida albicans. This suggests BAPs may target additional cellular mechanisms beyond membranes, PBPs, and ergosterols. Despite PoW's stronger antioxidant properties, both BAPs had comparable antibiofilm activity. These findings suggest complementary actions of BAPs from PoC and PoW both, in treating dental caries, offering broad-spectrum antimicrobial and antioxidant benefits.},
}

@article {pmid39600232,
year = {2024},
author = {Hurlow, J and Wolcott, RD and Bowler, PG},
title = {Clinical management of chronic wound infections: The battle against biofilm.},
journal = {Wound repair and regeneration : official publication of the Wound Healing Society [and] the European Tissue Repair Society},
volume = {},
number = {},
pages = {},
doi = {10.1111/wrr.13241},
pmid = {39600232},
issn = {1524-475X},
abstract = {Bacteria constitute the most abundant life form on earth, of which the majority exist in a protective biofilm state. Since the 1980s, we have learned much about the role of biofilm in human chronic infections, with associated global healthcare costs recently estimated at ~$386 billion. Chronic wound infection is a prominent biofilm-induced condition that is characterised by persistent inflammation and associated host tissue destruction, and clinical signs that are distinct from signs of acute wound infection. Biofilm also enables greater tolerance to antimicrobial agents in chronic wound infections compared with acute wound infections. Given the difficulty in eliminating wound biofilm, a multi-targeted strategy (namely biofilm-based wound care) involving debridement and antimicrobial therapies were introduced and have been practiced since the early 2000s. More recently, acknowledgement of the speed at which biofilm can develop and hence quickly interfere with wound healing has highlighted the need for an early anti-biofilm strategy to combat biofilm before it takes control and prevents wound healing. This strategy, referred to as wound hygiene, involves multiple tools in combination (debridement, cleansing, and antimicrobial dressings) to maximise success in biofilm removal and encourage wound healing. This review is intended to highlight the issues and challenges associated with biofilm-induced chronic infections, and specifically address the challenges in chronic wound management, and tools required to combat biofilm and encourage wound healing.},
}

@article {pmid39599508,
year = {2024},
author = {Taner, F and Baddal, B and Theodoridis, L and Petrovski, S},
title = {Biofilm Production in Intensive Care Units: Challenges and Implications.},
journal = {Pathogens (Basel, Switzerland)},
volume = {13},
number = {11},
pages = {},
pmid = {39599508},
issn = {2076-0817},
abstract = {The prevalence of infections amongst intensive care unit (ICU) patients is inevitably high, and the ICU is considered the epicenter for the spread of multidrug-resistant bacteria. Multiple studies have focused on the microbial diversity largely inhabiting ICUs that continues to flourish despite treatment with various antibiotics, investigating the factors that influence the spread of these pathogens, with the aim of implementing sufficient monitoring and infection control methods. Despite joint efforts from healthcare providers and policymakers, ICUs remain a hub for healthcare-associated infections. While persistence is a unique strategy used by these pathogens, multiple other factors can lead to persistent infections and antimicrobial tolerance in the ICU. Despite the recognition of the detrimental effects biofilm-producing pathogens have on ICU patients, overcoming biofilm formation in ICUs continues to be a challenge. This review focuses on various facets of ICUs that may contribute to and/or enhance biofilm production. A comprehensive survey of the literature reveals the apparent need for additional molecular studies to assist in understanding the relationship between biofilm regulation and the adaptive behavior of pathogens in the ICU environment. A better understanding of the interplay between biofilm production and antibiotic resistance within the environmental cues exhibited particularly by the ICU may also reveal ways to limit biofilm production and indivertibly control the spread of antibiotic-resistant pathogens in ICUs.},
}

@article {pmid39597869,
year = {2024},
author = {Maris, M and Martu, MA and Maris, M and Martu, C and Anton, DM and Pacurar, M and Earar, K},
title = {Clinical and Microbiological Periodontal Biofilm Evaluation of Patients with Type I Diabetes.},
journal = {Journal of clinical medicine},
volume = {13},
number = {22},
pages = {},
pmid = {39597869},
issn = {2077-0383},
abstract = {Background/Objectives: The purpose of this study was to assess the microbial composition and density of subgingival plaque samples for periodontal pathogens while correlating the values with glycemic control levels via glycated hemoglobin (HbA1c), a type of hemoglobin that has chemically linked glucose, in type I diabetes individuals who will undergo complex oral rehabilitation through orthodontic treatment and implant surgery. Methods: A cohort of 42 adults with type I diabetes were included in this study. The subjects sustained a comprehensive periodontal clinical examination as well as microbiological assessments of their subgingival plaque samples through quantitative real-time PCR. The samples were collected from the two deepest pockets of each subject. Results: The highest number of periodontopathogenic bacteria was observed in the pockets of 5-7 mm. T. forsythia showed the highest prevalence (20.48%), with decreasing numbers as follows: T. denticola (13.31%), P. gingivalis (11.26%), A. actinomycetemcomitans (7%), and P. intermedia (4.9%). T. denticola and T. forsythia were significantly more commonly observed in individuals with elevated HbA1c serum levels. No correlation was observed between P. gingivalis, A. actinomycetemcomitans, P. intermedia presence, and the HbA1c value. Conclusions: Periodontopathogenic agents' presence in subgingival biofilm samples varied in accordance with the pocket probing depth and metabolic control of the diabetic individuals. In our study, the appearance of these periodontopathogenic agents was linked to lowered metabolic control in patients with type I diabetes mellitus.},
}

@article {pmid39597697,
year = {2024},
author = {Nagy-Radványi, L and Ormai, E and Koloh, R and Ángyán, VD and Kocsis, B and Bencsik-Kerekes, E and Szabó, P and Csikós, E and Farkas, Á and Horváth, G and Kocsis, M and Balázs, VL},
title = {Biofilm Inhibition Activity of Fennel Honey, Fennel Essential Oil and Their Combination.},
journal = {Microorganisms},
volume = {12},
number = {11},
pages = {},
pmid = {39597697},
issn = {2076-2607},
support = {NKFIH PD 147156//Fund of National Research, Development and Innovation Office/ ; NKFIH PD 142122//Fund of National Research, Development and Innovation Office/ ; EKÖP-24-4-I-PTE-113//GYTK KA-2024- 05 and by University Research Scholarship Program of the Ministry for Culture and Innovation from the Source of the National Research, Development and Innovation Fund/ ; EKÖP-24-4-II-PTE-114//GYTK KA-2024- 05 and by University Research Scholarship Program of the Ministry for Culture and Innovation from the Source of the National Research, Development and Innovation Fund/ ; },
abstract = {The eradication of bacterial biofilms remains a persistent challenge in medicine, particularly because an increasing number of biofilms exhibit resistance to conventional antibiotics. This underscores the importance of searching for novel compounds that present antibacterial and biofilm inhibition activity. Various types of honey and essential oil were proven to be effective against a number of biofilm-forming bacterial strains. The current study demonstrated the effectiveness of the relatively unexplored fennel honey (FH), fennel essential oil (FEO), and their combination against biofilm-forming bacterial strains Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and Escherichia coli, with a series of in vitro experiments. The authenticity of FH and FEO was checked with light microscopy and gas chromatography-mass spectrometry, respectively. Minimum inhibitory concentrations were determined using the microdilution method, and antibiofilm activity was assessed with crystal violet assay. Structural changes in bacterial cells and biofilms, induced by the treatments, were monitored with scanning electron microscopy. FEO and FH inhibited the biofilm formation of each bacterial strain, with FEO being more effective compared to FH. Their combination was the most effective, with inhibitory rates ranging between 87 and 92%, depending on the bacterial strain. The most sensitive bacterium was E. coli, while P. aeruginosa was the most resistant. These results provide justification for the combined use of honey and essential oil to suppress bacterial biofilms and can serve as a starting point to develop an effective surface disinfectant with natural ingredients.},
}

@article {pmid39597686,
year = {2024},
author = {Sebbane, N and Abramovitz, I and Kot-Limon, N and Steinberg, D},
title = {Mechanistic Insight into the Anti-Bacterial/Anti-Biofilm Effects of Low Chlorhexidine Concentrations on Enterococcus faecalis-In Vitro Study.},
journal = {Microorganisms},
volume = {12},
number = {11},
pages = {},
pmid = {39597686},
issn = {2076-2607},
abstract = {BACKGROUND: Endodontic treatment failures are often linked to the persistence of Enterococcus faecalis in the root canal system. This study aimed to investigate the antibacterial/antibiofilm mechanism of chlorhexidine (CHX), particularly at low concentrations, against E. faecalis, to improve endodontic treatment protocols.

METHODS: The antibacterial activity of CHX (0.125-20 μg/mL) was evaluated against E. faecalis ATCC 29212 using various assays, including planktonic growth inhibition, colony-forming units (CFUs), membrane permeability and potential assays, high-resolution scanning electron microscopy (HR-SEM), confocal laser scanning microscopy of biofilms, biomass and metabolic activity assays on matured biofilm, and quantitative real-time PCR for gene expression. Statistical analysis was performed using Student's t-test and ANOVA.

RESULTS: CHX demonstrated concentration-dependent inhibition of E. faecalis, significantly reducing planktonic growth and CFUs. Membrane assays showed increased permeability and depolarization, indicating damage. HR-SEM revealed morphological changes, such as pore formation, while confocal microscopy showed a reduction in biofilm mass and extracellular substances. Gene expression analysis indicated the downregulation of virulence genes and upregulation of stress response genes.

CONCLUSIONS: CHX at low concentrations disrupts E. faecalis at multiple levels, from membrane disruption to gene expression modulation, affecting mature biofilm. These findings support the refinement of endodontic disinfection protocols to reduce microbial persistence.},
}

@article {pmid39597673,
year = {2024},
author = {Gallina, NLF and Irizarry Tardi, N and Li, X and Cai, A and Horn, MJ and Applegate, BM and Reddivari, L and Bhunia, AK},
title = {Assessment of Biofilm Formation and Anti-Inflammatory Response of a Probiotic Blend in a Cultured Canine Cell Model.},
journal = {Microorganisms},
volume = {12},
number = {11},
pages = {},
pmid = {39597673},
issn = {2076-2607},
support = {2021-38420-34058//USDA-NIFA/ ; 1016249//USDA-NIFA/ ; },
abstract = {Gut dysbiosis and an inflamed bowel are growing concerns in mammals, including dogs. Probiotic supplements have been used to restore the natural microbial community and improve gastrointestinal health. Biofilm formation, antimicrobial activities, and immunological responses of probiotics are crucial to improving gut health. Thus, we tested a commercial probiotic blend (LabMAX-3), a canine kibble additive comprising Lactobacillus acidophilus, Lacticaseibacillus casei, and Enterococcus faecium for their ability to inactivate common enteric pathogens; their ability to form biofilms; epithelial cell adhesion; and their anti-inflammatory response in the Madin-Darby Canine Kidney (MDCK) cell line. Probiotic LabMAX-3 blend or individual isolates showed a strong inhibitory effect against Salmonella enterica, Listeria monocytogenes, enterotoxigenic Escherichia coli, and Campylobacter jejuni. LabMAX-3 formed biofilms comparable to Staphylococcus aureus. LabMAX-3 adhesion to the MDCK cell line (with or without lipopolysaccharide (LPS) pretreatment) showed comparable adhesion and biofilm formation (p < 0.05) to L. casei ATCC 334 used as a control. LabMAX-3 had no cytotoxic effects on the MDCK cell line during 1 h exposure. The interleukin-10 (IL-10) and tumor necrosis factor alpha (TNFα) ratio of LabMAX-3, compared to the L. casei control, showed a significant increase (p < 0.05), indicating a more pronounced anti-inflammatory response. The data show that LabMAX-3, a canine kibble supplement, can improve gastrointestinal health.},
}

@article {pmid39597647,
year = {2024},
author = {Niazy, AA and Alrashed, MM and Lambarte, RNA and Niazy, AA},
title = {5-Fluorouracil Inhibits Bacterial Growth and Reduces Biofilm in Addition to Having Synergetic Effects with Gentamicin Against Pseudomonas aeruginosa.},
journal = {Microorganisms},
volume = {12},
number = {11},
pages = {},
pmid = {39597647},
issn = {2076-2607},
abstract = {Pseudomonas aeruginosa is a multidrug-resistant pathogen known for chronic infections, mainly due to biofilm formation. This study aimed to explore the potential repurposing of 5-fluorouracil (5-FU), an anticancer drug, to treat P. aeruginosa infections. Firstly, we investigated the inhibitory effects of 5-FU on bacterial growth using the microdilution method. Secondly, the impact of 5-FU on biofilm formation and disassembly was assessed via biofilm biomass measurements with the crystal violet staining method and confocal microscopy analyses. Lastly, the potential synergy between 5-FU and the antibiotics gentamicin and meropenem was evaluated using a checkerboard assay. Results revealed that 5-FU inhibited bacterial growth in a dose-dependent manner, with 100% inhibition observed at concentrations of 25 µg/mL and higher. Also, 70% and 100% reductions in biofilm biomass were demonstrated at concentrations of 12 and 100 µg/mL, respectively. Controversy, these higher concentrations unexpectedly increased biofilm biomass in pre-formed biofilms. Synergistic interactions were observed between 5-FU and gentamicin in both growth inhibition (FICI 0.31) and biofilm inhibition (ZIP 14.1), while no synergy was found with meropenem. These findings highlight the potential of 5-FU as an adjunctive therapy for P. aeruginosa infections, especially in combination with gentamicin. However, further research is required to address 5-FU limitations against mature biofilms.},
}

@article {pmid39597626,
year = {2024},
author = {Galelli, ME and Cristóbal-Miguez, JAE and Cárdenas-Aguiar, E and García, AR and Paz-González, A and Sarti, GC},
title = {The Effects of Seed Inoculation with Bacterial Biofilm on the Growth and Elemental Composition of Tomato (Solanum lycopersicum L.) Cultivated on a Zinc-Contaminated Substrate.},
journal = {Microorganisms},
volume = {12},
number = {11},
pages = {},
doi = {10.3390/microorganisms12112237},
pmid = {39597626},
issn = {2076-2607},
abstract = {Biofilm obtained from Bacillus subtilis subsp. spizizenii inoculated on vegetable seeds has been shown to have plant growth-promoting capacity. Seed inoculation with biofilm produced by this strain could also reduce the adverse effects on plant growth caused by soil or substrate heavy metal overabundance. Therefore, the objective of this work was to evaluate the impact of biofilm inoculated on tomato (Solanum lycopersicum L.) seeds, which were planted on a substrate with artificially added zinc. First, seeds of the Río Grande tomato variety were exposed to increasing zinc concentrations, namely: 50, 100, 200, and 400 ppm, with and without bacterial biofilm inoculation. Zinc addition and seed inoculation affected germination parameters. For example, an extra 200 and 400 ppm of zinc led to high toxicity. Biofilm inoculation, however, reduced the noxious effects of excess zinc, bringing acute toxicity down to moderate. Then, tomato plants growing from inoculated and non-inoculated seeds were cropped for 4 months in both substrates with 400 ppm zinc and without added zinc. Extra zinc addition significantly (p < 0.05) reduced tomato root and shoot biomass, plant height, and fruit number at harvest time. However, seed biofilm inoculation avoided the harmful effect of zinc on plant growth parameters, fruit yield, and fruit quality. The roots and shoots of plants growing on contaminated substrates showed very noticeable increases in zinc levels compared to the control, while fruits only showed a much weaker zinc gain, even if this was significant (p < 0.05). Moreover, root shoot and fruit concentrations of elements other than zinc, (nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, manganese, copper, lead, and cadmium) were not or only weakly affected by the addition of this metal to the substrate. In summary, the biofilm of B. subtilis proved to be effective as a bioinoculant to alleviate negative effects on tomatoes cropped in a substrate with excess zinc.},
}

@article {pmid39597620,
year = {2024},
author = {Grzech-Leśniak, Z and Szwach, J and Lelonkiewicz, M and Migas, K and Pyrkosz, J and Szwajkowski, M and Kosidło, P and Pajączkowska, M and Wiench, R and Matys, J and Nowicka, J and Grzech-Leśniak, K},
title = {Effect of Nd:YAG Laser Irradiation on the Growth of Oral Biofilm.},
journal = {Microorganisms},
volume = {12},
number = {11},
pages = {},
doi = {10.3390/microorganisms12112231},
pmid = {39597620},
issn = {2076-2607},
support = {SKN 255//Wroclaw Medical University/ ; },
abstract = {BACKGROUND: Oral microbiota comprises a wide variety of microorganisms. The purpose of this study was to evaluate the effects of Nd:YAG laser with a 1064 nm wavelength on the in vitro growth of Candida albicans, Candida glabrata, and Streptococcus mutans clinical strains, as well as their biofilm. The study also aimed to determine whether the parameters recommended for photobiomodulation (PBM) therapy, typically used for tissue wound healing, have any additional antibacterial or antifungal effects.

MATERIAL AND METHODS: Single- and dual-species planktonic cell solution and biofilm cultures of Streptococcus mutans, Candida albicans, and Candida glabrata were irradiated using an Nd:YAG laser (LightWalker; Fotona; Slovenia) with a flat-top Genova handpiece. Two test groups were evaluated: Group 1 (G-T1) exposed to low power associated parameters (irradiance 0.5 W/cm[2]) and Group 2 (G-T2) with higher laser parameters (irradiance 1.75 W/cm[2]). Group 3 (control) was not exposed to any irradiation. The lasers' effect was assessed both immediately after irradiation (DLI; Direct Laser Irradiation) and 24 h post-irradiation (24hLI) of the planktonic suspension using a quantitative method (colony-forming units per 1 mL of suspension; CFU/mL), and the results were compared with the control group, in which no laser was applied. The impact of laser irradiation on biofilm biomass was assessed immediately after laser irradiation using the crystal violet method.

RESULTS: Nd:YAG laser irradiation with photobiomodulation setting demonstrated an antimicrobial effect with the greatest immediate reduction observed in S. mutans, achieving up to 85.4% reduction at the T2 settings. However, the laser's effectiveness diminished after 24 h. In single biofilm cultures, the highest reductions were noted for C. albicans and S. mutans at the T2 settings, with C. albicans achieving a 92.6 ± 3.3% reduction and S. mutans reaching a 94.3 ± 5.0% reduction. Overall, the T2 settings resulted in greater microbial reductions compared to T1, particularly in biofilm cultures, although the effectiveness varied depending on the microorganism and culture type. Laser irradiation, assessed immediately after using the crystal violet method, showed the strongest biofilm reduction for Streptococcus mutans in the T2 settings for both single-species and dual-species biofilms, with higher reductions observed in all the microbial samples at the T2 laser parameters (p < 0.05) Conclusion: The Nd:YAG laser using standard parameters typically applied for wound healing and analgesic effects significantly reduced the number of Candida albicans; Candida glabrata; and Streptococcus mutans strains.},
}

@article {pmid39597612,
year = {2024},
author = {Chen, R and Saint Bezard, J and Swann, MJ and Watson, F and Percival, SL},
title = {An In Vitro Artificial Wound Slough-Biofilm Model Developed for Evaluating a Novel Antibiofilm Technology.},
journal = {Microorganisms},
volume = {12},
number = {11},
pages = {},
doi = {10.3390/microorganisms12112223},
pmid = {39597612},
issn = {2076-2607},
abstract = {Eschar and slough in wounds serve as a reservoir for microorganisms and biofilms, damaged/devitalised cells, and inflammatory chemokines/cytokines, which work to initiate and prolong persistent inflammation and increase the risk of infection. Biofilm-related inflammation and infections are considered to be highly prevalent in acute wounds and chronic wounds. As slough is known to harbour biofilms, measuring the efficacy of antimicrobials in killing microbes both within and under slough is warranted. This highlights the need for more clinically relevant wound biofilm models to address this significant clinical need. Consequently, in this study, we developed an in vitro artificial wound slough (AWS) biofilm model produced by forming a biofilm below a layer of AWS, the latter of which was composed of the main protein components reported in wound eschar and slough, namely collagen, elastin, and fibrin. The model was employed to investigate the antibiofilm and antibacterial efficacy of a new patented smart next-generation antibiofilm technology composed of silver-zinc EDTA complexes and designed as a family of multifunctional metal complexes referred to as MMCs, in a liquid format, and to determine both the performance and penetration through AWS to control and manage biofilms. The results demonstrated the ability of the AWS-biofilm model to be employed for the evaluation of the efficacy of a new antibiofilm and antimicrobial next-generation smart technology. The results also demonstrated the potential for the proprietary EDTA multifunctional metal complexes to be used for the disruption of biofilms, such as those that form in chronic wounds.},
}

@article {pmid39597514,
year = {2024},
author = {Kostoglou, D and Apostolopoulou, M and Lagou, A and Didos, S and Argiriou, A and Giaouris, E},
title = {Investigating the Potential of L(+)-Lactic Acid as a Green Inhibitor and Eradicator of a Dual-Species Campylobacter spp. Biofilm Formed on Food Processing Model Surfaces.},
journal = {Microorganisms},
volume = {12},
number = {11},
pages = {},
doi = {10.3390/microorganisms12112124},
pmid = {39597514},
issn = {2076-2607},
support = {5046750//EPAnEk-NRSF 2014-2020/ ; },
abstract = {Campylobacter spp. are prevalent foodborne bacterial enteric pathogens. Their inclusion in biofilms on abiotic surfaces is considered a strategy that facilitates their extraintestinal survival. Organic acid (OA) treatments could be used in a green approach to decontaminate various surfaces. This work aimed to evaluate the inhibitory and eradicative effects of L(+)-lactic acid (LA), a naturally occurring OA, on a dual-species biofilm formed on two food processing model surfaces (polystyrene and stainless steel) by three selected foodborne Campylobacter spp. isolates (two C. jejuni and one C. coli). The influence of aerobiosis conditions (microaerophilic, aerobic and CO2 enriched) on the resistance of the established biofilms to the acid was also tested. In parallel, the predominant metabolites contained in the planktonic media of biofilm monocultures and mixed-culture biofilm were comparatively analyzed by an untargeted metabolomics approach. Results revealed that LA inhibited mixed-culture biofilm formation by more than 2 logs (>99%) on both surfaces when this was applied at its highest tested concentration (4096 μg/mL; 0.34% v/v). However, all the preformed mixed-culture biofilms (ca. 10[6-7] CFU/cm[2]) could not be eradicated even when the acid was used at concentrations exceeding 5% v/v, denoting their extremely high recalcitrance which was still influenced by the abiotic substratum, and the biofilm-forming aerobiosis conditions. The metabolic analysis revealed a strain-specific metabolite production which might also be related to the strain-specific biofilm-forming and resistance behaviors and resulted in the distinct clustering of the different samples. Overall, the current findings provide important information on the effectiveness of LA against biofilm campylobacteria and may assist in mitigating their risk in the food chain.},
}

@article {pmid39597505,
year = {2024},
author = {Høiby, N and Moser, C and Ciofu, O},
title = {Pseudomonas aeruginosa in the Frontline of the Greatest Challenge of Biofilm Infection-Its Tolerance to Antibiotics.},
journal = {Microorganisms},
volume = {12},
number = {11},
pages = {},
doi = {10.3390/microorganisms12112115},
pmid = {39597505},
issn = {2076-2607},
abstract = {P. aeruginosa biofilms are aggregates of bacteria surrounded by a self-produced matrix which binds to some antibiotics such as aminoglycosides. P. aeruginosa biofilms are tolerant to antibiotics. The treatment of biofilm infections leads to a recurrence of symptoms after finishing antibiotic treatment, although the initial clinical response to the treatment is frequently favorable. There is a concentration gradient of oxygen and nutrients from the surface to the center of biofilms. Surface-located bacteria are multiplying and metabolizing, whereas deeper located bacteria are dormant and tolerant to most antibiotics. Colistin kills dormant bacteria, and combination therapy with colistin and antibiotics which kills multiplying bacteria is efficient in vitro. Some antibiotics such as imipenem induce additional production of the biofilm matrix and of chromosomal beta-lactamase in biofilms. Biofilms present a third Pharmacokinetic/Pharmacodynamic (PK/PD) micro-compartment (first: blood, second: tissue, third: biofilm) which must be taken into consideration when calculations try to predict the antibiotic concentrations in biofilms and thereby the probability of target attainment (PTA) for killing the biofilm. Treating biofilms with hyperbaric oxygen to wake up the dormant cells, destruction of the biofilm matrix, and the use of bacteriophage therapy in combination with antibiotics are promising possibilities which have shown proof of concept in in vitro experiments and in animal experiments.},
}

@article {pmid39596757,
year = {2024},
author = {Grygiel, I and Bajrak, O and Wójcicki, M and Krusiec, K and Jończyk-Matysiak, E and Górski, A and Majewska, J and Letkiewicz, S},
title = {Comprehensive Approaches to Combatting Acinetobacter baumannii Biofilms: From Biofilm Structure to Phage-Based Therapies.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {13},
number = {11},
pages = {},
doi = {10.3390/antibiotics13111064},
pmid = {39596757},
issn = {2079-6382},
abstract = {Acinetobacter baumannii-a multidrug-resistant (MDR) pathogen that causes, for example, skin and soft tissue wounds; urinary tract infections; pneumonia; bacteremia; and endocarditis, particularly due to its ability to form robust biofilms-poses a significant challenge in clinical settings. This structure protects the bacteria from immune responses and antibiotic treatments, making infections difficult to eradicate. Given the rise in antibiotic resistance, alternative therapeutic approaches are urgently needed. Bacteriophage-based strategies have emerged as a promising solution for combating A. baumannii biofilms. Phages, which are viruses that specifically infect bacteria, offer a targeted and effective means of disrupting biofilm and lysing bacterial cells. This review explores the current advancements in bacteriophage therapy, focusing on its potential for treating A. baumannii biofilm-related infections. We described the mechanisms by which phages interact with biofilms, the challenges in phage therapy implementation, and the strategies being developed to enhance its efficacy (phage cocktails, engineered phages, combination therapies with antibiotics). Understanding the role of bacteriophages in both biofilm disruption and in inhibition of its forming could pave the way for innovative treatments in combating MDR A. baumannii infections as well as the prevention of their development.},
}

@article {pmid39596741,
year = {2024},
author = {Tortella Fuentes, G and Fincheira, P and Rubilar, O and Leiva, S and Fernandez, I and Schoebitz, M and Pelegrino, MT and Paganotti, A and Dos Reis, RA and Seabra, AB},
title = {Nanoparticle-Based Nitric Oxide Donors: Exploring Their Antimicrobial and Anti-Biofilm Capabilities.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {13},
number = {11},
pages = {},
doi = {10.3390/antibiotics13111047},
pmid = {39596741},
issn = {2079-6382},
support = {220003/WT_/Wellcome Trust/United Kingdom ; },
abstract = {Background: Nitric oxide (NO) is an antimicrobial and anti-biofilm agent with significant potential for combating biofilm-associated infections and antibiotic resistance. However, owing to its high reactivity due to the possession of a free radical and short half-life (1-5 s), the practical application of NO in clinical settings is challenging. Objectives: This review explores the development of NO-releasing nanoparticles that provide a controlled, targeted delivery system for NO, enhancing its antimicrobial efficacy while minimizing toxicity. The review discusses various NO donors, nanoparticle platforms, and how NO disrupts biofilm formation and eradicates pathogens. Additionally, we examine the highly encouraging and inspiring results of NO-releasing nanoparticles against multidrug-resistant strains and their applications in medical and environmental contexts. This review highlights the promising role of NO-based nanotechnologies in overcoming the challenges posed by increasing antibiotic resistance and biofilm-associated infections. Conclusions: Although NO donors and nanoparticle delivery systems show great potential for antimicrobial and anti-biofilm uses, addressing challenges related to controlled release, toxicity, biofilm penetration, resistance, and clinical application is crucial.},
}

@article {pmid39596734,
year = {2024},
author = {Avila-Novoa, MG and Solis-Velazquez, OA and Guerrero-Medina, PJ and Martínez-Chávez, L and Martínez-Gonzáles, NE and Gutiérrez-Lomelí, M},
title = {Listeria monocytogenes in Fruits and Vegetables: Antimicrobial Resistance, Biofilm, and Genomic Insights.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {13},
number = {11},
pages = {},
doi = {10.3390/antibiotics13111039},
pmid = {39596734},
issn = {2079-6382},
abstract = {BACKGROUND/OBJECTIVES: Listeria monocytogenes is a foodborne pathogen that can infect both humans and animals and cause noninvasive gastrointestinal listeriosis or invasive listeriosis. The objectives of this study were to determine the genetic diversity of L. monocytogenes; the genes associated with its resistance to antibiotics, benzalkonium chloride (BC), and cadmium chloride (CdCl2); and its biofilm formation.

METHODS: A total of 132 fresh fruits (44 samples) and vegetables (88 samples) were selected for this study. The genetic diversity of the isolates and the genes associated with their antibiotic resistance were determined using PCR amplification; meanwhile, their levels of susceptibility to antibiotics were determined using the agar diffusion method. Their levels of resistance to BC and CdCl2 were determined using the minimum inhibitory concentration method, and their capacity for biofilm formation was evaluated using the crystal violet staining method.

RESULTS: A total of 17 L. monocytogenes strains were collected: 12.8% (17/132) from fresh fruits and vegetables in this study. The isolates of L. monocytogenes belonged to phylogenetic groups I.1 (29.4% (5/17); serotype 1/2a) and II.2 (70.5% (12/17); serotype 1/2b); strains containing Listeria pathogenicity islands (LIPIs) were also identified at prevalence rates of 100% for LIPI-1 and LIPI-2 (17/17), 29.4% for LIPI-3 (5/17), and 11.7% for LIPI-4 (2/17). The antibiotic susceptibility tests showed that the L. monocytogenes isolates exhibited six different multiresistant patterns, with multiple antibiotic resistance (MAR) index of ≥0.46 (70.5%; 12/17); additionally, the genes Ide, tetM, and msrA, associated with efflux pump Lde, tetracycline, and ciprofloxacin resistance, were detected at 52.9% (9/17), 29.4% (5/17), and 17.6% (3/17), respectively. The phenotypic tests showed that 58.8% (10/17) of cadmium-resistant L. monocytogenes isolates had a co-resistance of 23.5% (4/17) to BC. Finally, all strains of L. monocytogenes exhibited moderate biofilm production.

CONCLUSIONS: The results of this study contribute to our understanding of the persistence and genetic diversity of L. monocytogenes strains isolated from fresh fruits and vegetables; in addition, their resistance to CdCl2, which is correlated with co-resistance to BC disinfectant, is helpful for the food industry.},
}

@article {pmid39596709,
year = {2024},
author = {Lannes-Costa, PS and Fernandes, IR and Pena, JMS and Costa, BRFV and Cunha, MMLD and Ferreira-Carvalho, BT and Nagao, PE},
title = {Antibiotic Resistance and Presence of Persister Cells in the Biofilm-like Environments in Streptococcus agalactiae.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {13},
number = {11},
pages = {},
doi = {10.3390/antibiotics13111014},
pmid = {39596709},
issn = {2079-6382},
support = {PDR10 E-26/204.521/ 2021//Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro/ ; E-26/210.373/2024//Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro/ ; PrInt 88887.3115972018-00//Coordenação de Aperfeicoamento de Pessoal de Nível Superior/ ; Finance Code 001//Coordenação de Aperfeicoamento de Pessoal de Nível Superior/ ; },
abstract = {Objectives: This study investigated antibiotic resistance and presence of persister cells in Streptococcus agalactiae strains belonging to capsular types Ia/ST-103, III/ST-17, and V/ST-26 in biofilm-like environments. Results: S. agalactiae strains were susceptible to penicillin, clindamycin, and erythromycin. Resistance genes were associated with tetM (80%), tetO (20%), ermB (80%), and linB (40%). Persister cells were detected in bacterial strains exposed to high concentrations of penicillin, clindamycin, and erythromycin. S. agalactiae capsular type III/ST-17 exhibited the highest percentage of persister cells in response to penicillin and clindamycin, while type Ia/ST-103 presented the lowest percentages of persister cells for all antimicrobials tested. Additionally, persister cells were also detected at lower levels for erythromycin, regardless of capsular type or sequence type. Further, all S. agalactiae isolates presented efflux pump activity in ethidium bromide-refractory cell assays. LIVE/DEAD fluorescence microscopy confirmed the presence of >85% viable persister cells after antibiotic treatment. Conclusions: These findings suggest that persister cells play a key role in the persistence of S. agalactiae during antibiotic therapy, interfering with the treatment of invasive infections. Monitoring persister formation is crucial for developing strategies to combat recurrent infections caused by this pathogen.},
}

@article {pmid39596695,
year = {2024},
author = {Sánchez, MC and Hernández, P and Velapatiño, Á and Cuba, E and Ciudad, MJ and Collado, L},
title = {Illumina Sequencing in Conjunction with Propidium Monoazide to Identify Live Bacteria After Antiseptic Treatment in a Complex Oral Biofilm: A Study Using an Ex Vivo Supragingival Biofilm Model.},
journal = {Antibiotics (Basel, Switzerland)},
volume = {13},
number = {11},
pages = {},
doi = {10.3390/antibiotics13111000},
pmid = {39596695},
issn = {2079-6382},
abstract = {Background/Objectives: The evaluation of the efficacy of antibacterial treatments in complex oral ecosystems is limited by the inability to differentiate live from dead bacteria using omic techniques. The objective of this study was therefore to assess the ability of the combination of the 16S rRNA Illumina sequencing methodology and the action of propidium monoazide (PMA) to study viable bacterial profiles in oral biofilms after exposure to an antiseptic compound. Methods: Cariogenic supragingival biofilms were developed in an ex vivo model for 96 h, using saliva from healthy volunteers. The biofilms were treated with 0.12% chlorhexidine (CHX) combined with 0.05% cetylpyridinium chloride (CPC), for 60 s, using phosphate buffered saline as a control. After exposure, each biofilm was treated or not with PMA to then extract the bacterial DNA, quantify it by Qubit, quantify the bacterial population using qPCR, and perform the metataxonomic study of the samples using Illumina 16S rRNA sequencing. Results: A significantly lower DNA concentration in the PMA-treated biofilms (p < 0.05 compared with those not exposed to PMA) was observed. The viable bacterial count obtained by qPCR differed significantly from the total bacterial count in the biofilm samples exposed to the antiseptic (p < 0.05). The viable microbiome differed significantly from the total bacterial profile of the samples treated with CHX/CPC after exposure to PMA (p < 0.05 at the α- and β-diversity levels). Conclusions: The combination of Illumina 16S rRNA sequencing and PMA helps solve the inability to evaluate the efficacy of antibacterial treatments in the bacterial profile of complex ecosystems such as oral biofilms.},
}

@article {pmid39596287,
year = {2024},
author = {Krzyżek, P},
title = {Helicobacter pylori Efflux Pumps: A Double-Edged Sword in Antibiotic Resistance and Biofilm Formation.},
journal = {International journal of molecular sciences},
volume = {25},
number = {22},
pages = {},
doi = {10.3390/ijms252212222},
pmid = {39596287},
issn = {1422-0067},
mesh = {*Helicobacter pylori/drug effects/metabolism/genetics/physiology ; *Biofilms/drug effects/growth & development ; *Anti-Bacterial Agents/pharmacology ; *Bacterial Proteins/metabolism/genetics ; *Membrane Transport Proteins/metabolism/genetics ; Humans ; Drug Resistance, Bacterial ; Helicobacter Infections/drug therapy/microbiology ; },
abstract = {Helicobacter pylori is a major pathogen associated with various gastric diseases. Despite decades of research, the treatment of H. pylori remains challenging. One of the primary mechanisms contributing to failures of therapies targeting this bacterium is genetic mutations in drug target sites, although the growing body of scientific data highlights that efflux pumps may also take part in this process. Efflux pumps are proteinaceous transporters actively expelling antimicrobial agents from the interior of the targeted cells and reducing the intracellular concentration of these compounds. Considering that efflux pumps contribute to both antimicrobial resistance and biofilm formation, an in-depth understanding of their properties may constitute a cornerstone in the development of novel therapeutics against H. pylori. In line with this, the aim of the current review is to describe the multitude of efflux pumps produced by H. pylori and present the data describing the involvement of these proteins in tolerance and/or resistance to various classes of antimicrobial substances.},
}

*Helicobacter pylori/drug effects/metabolism/genetics/physiology
*Biofilms/drug effects/growth & development
*Anti-Bacterial Agents/pharmacology
*Bacterial Proteins/metabolism/genetics
*Membrane Transport Proteins/metabolism/genetics
Humans
Drug Resistance, Bacterial
Helicobacter Infections/drug therapy/microbiology

@article {pmid39596223,
year = {2024},
author = {Phuengmaung, P and Chongrak, C and Saisorn, W and Makjaroen, J and Singkham-In, U and Leelahavanichkul, A},
title = {The Coexistence of Klebsiella pneumoniae and Candida albicans Enhanced Biofilm Thickness but Induced Less Severe Neutrophil Responses and Less Inflammation in Pneumonia Mice Than K. pneumoniae Alone.},
journal = {International journal of molecular sciences},
volume = {25},
number = {22},
pages = {},
doi = {10.3390/ijms252212157},
pmid = {39596223},
issn = {1422-0067},
support = {HEAF67300087//Thailand Science research and Innovation Fund Chulalongkorn University/ ; },
mesh = {Animals ; *Biofilms/growth & development ; *Klebsiella pneumoniae/physiology ; *Candida albicans/physiology ; *Neutrophils/immunology/metabolism ; Mice ; *Klebsiella Infections/microbiology/immunology ; Mice, Inbred C57BL ; Cytokines/metabolism ; Inflammation/pathology ; Extracellular Traps/metabolism ; Pneumonia/microbiology/immunology ; Humans ; },
abstract = {Due to the possible coexistence of Klebsiella pneumoniae (KP) and Candida albicans (CA), strains of KP and CA with biofilm production properties clinically isolated from patients were tested. The production of biofilms from the combined organisms (KP+CA) was higher than the biofilms from each organism alone, as indicated by crystal violet and z-stack immunofluorescence. In parallel, the bacterial abundance in KP + CA was similar to KP, but the fungal abundance was higher than CA (culture method), implying that CA grows better in the presence of KP. Proteomic analysis was performed to compare KP + CA biofilm to KP biofilm alone. With isolated mouse neutrophils (thioglycolate induction), KP + CA biofilms induced less prominent responses than KP biofilms, as determined by (i) neutrophilic supernatant cytokines (ELISA) and (ii) neutrophil extracellular traps (NETs), using immunofluorescent images (neutrophil elastase, myeloperoxidase, and citrullinated histone 3), peptidyl arginine deiminase 4 (PAD4) expression, and cell-free DNA. Likewise, intratracheal KP + CA in C57BL/6 mice induces less severe pneumonia than KP alone, as indicated by organ injury (serum creatinine and alanine transaminase) (colorimetric assays), cytokines (ELISA), bronchoalveolar lavage fluid parameters (bacterial culture and neutrophil abundances using a hemocytometer), histology score (H&E stains), and NETs (immunofluorescence on the lung tissue). In conclusion, the biofilm biomass of KP + CA was mostly produced from CA with less potent neutrophil activation and less severe pneumonia than KP alone. Hence, fungi in the respiratory tract might benefit the host in some situations, despite the well-known adverse effects of fungi.},
}

Animals
*Biofilms/growth & development
*Klebsiella pneumoniae/physiology
*Candida albicans/physiology
*Neutrophils/immunology/metabolism
Mice
*Klebsiella Infections/microbiology/immunology
Mice, Inbred C57BL
Cytokines/metabolism
Inflammation/pathology
Extracellular Traps/metabolism
Pneumonia/microbiology/immunology
Humans

@article {pmid39596184,
year = {2024},
author = {Wang, Z and Wu, Y and Liu, M and Chen, L and Xiao, K and Huang, Z and Zhao, Y and Wang, H and Ding, Y and Lin, X and Zeng, J and Peng, F and Zhang, J and Wang, J and Wu, Q},
title = {The Gene Cluster Cj0423-Cj0425 Negatively Regulates Biofilm Formation in Campylobacter jejuni.},
journal = {International journal of molecular sciences},
volume = {25},
number = {22},
pages = {},
doi = {10.3390/ijms252212116},
pmid = {39596184},
issn = {1422-0067},
support = {2023YFD1801000//National Key Research and Development Program of China/ ; 2020B0301030005//Guangdong Major Project of Basic and Applied Basic Research/ ; 2021TQ06N119//Talent Support Project of Guangdong/ ; 2022GDASZH-2022020402-1//Guangdong Academy of Sciences Project/ ; },
mesh = {*Biofilms/growth & development ; *Campylobacter jejuni/genetics/physiology/growth & development/metabolism ; *Multigene Family ; *Bacterial Proteins/genetics/metabolism ; *Gene Expression Regulation, Bacterial ; Quorum Sensing/genetics ; Flagella/genetics/metabolism ; Fatty Acids/metabolism ; },
abstract = {Campylobacter jejuni (C. jejuni) is a zoonotic foodborne pathogen that is widely distributed worldwide. Its optimal growth environment is microaerophilic conditions (5% O2, 10% CO2), but it can spread widely in the atmospheric environment. Biofilms are thought to play an important role in this process. However, there are currently relatively few research works on the regulatory mechanisms of C. jejuni biofilm formation. In this study, a pan-genome analysis, combined with the analysis of biofilm phenotypic information, revealed that the gene cluster Cj0423-Cj0425 is associated with the negative regulation of biofilm formation in C. jejuni. Through gene knockout experiments, it was observed that the Cj0423-Cj0425 mutant strain significantly increased biofilm formation and enhanced flagella formation. Furthermore, pull-down assay revealed that Cj0424 interacts with 93 proteins involved in pathways such as fatty acid synthesis and amino acid metabolism, and it also contains the quorum sensing-related gene luxS. This suggests that Cj0423-Cj0425 affects fatty acid synthesis and amino acid metabolism, influencing quorum sensing and strain motility, ultimately inhibiting biofilm formation.},
}

*Biofilms/growth & development
*Campylobacter jejuni/genetics/physiology/growth & development/metabolism
*Multigene Family
*Bacterial Proteins/genetics/metabolism
*Gene Expression Regulation, Bacterial
Quorum Sensing/genetics
Flagella/genetics/metabolism
Fatty Acids/metabolism

@article {pmid39595342,
year = {2024},
author = {Huang, Y and Chen, P and Cao, H and Zhou, Z and Xu, T},
title = {Characterization of Pseudomonas aeruginosa Isolated from Bovine Mastitis in Northern Jiangsu Province and Correlation to Drug Resistance and Biofilm Formability.},
journal = {Animals : an open access journal from MDPI},
volume = {14},
number = {22},
pages = {},
doi = {10.3390/ani14223290},
pmid = {39595342},
issn = {2076-2615},
support = {32102731//National Natural Science Foundation of China/ ; 2023M732994//China Postdoctoral Science Foundation/ ; IJRLD-KF202214//The Open Project Program of International Joint Research Laboratory in Universities of Jiangsu Province of China for Domestic Animal Germplasm Resources and Genetic Improvement/ ; },
abstract = {This study aimed to provide experimental support for the prevention and treatment of Pseudomonas aeruginosa infections and to elucidate the epidemiological distribution of resistance and virulence genes of Pseudomonas aeruginosa from mastitis in dairy cows in the northern part of Jiangsu Province and their relationship with the biofilm-forming ability of the strains. Mastitis presents a significant challenge within dairy farming, adversely impacting the health of dairy cows and precipitating substantial economic losses in milk production. In this study, Pseudomonas aeruginosa (PA) was isolated and identified from mastitis milk samples in Jiangsu Province, China. In order to characterize the isolates, multilocus sequence typing (MLST), drug resistance phenotypes, virulence genes, and biofilm formations were detected. The isolation and identification of pathogenic bacteria from 168 clinical mastitis milk samples using 16S rRNA and PCR revealed 63 strains of Pseudomonas aeruginosa, which were determined to be highly homologous according to phylogenetic tree analysis. In addition, the MLST indicated five major ST types, namely ST277, ST450, ST571, ST641, and ST463. The susceptibility to 10 antimicrobials was determined, and it was found that 63 strains of Pseudomonas aeruginosa did not have a strong resistance to the antimicrobials in general. However, there were differences in the phenotypes' resistance to antimicrobials among the different ST types. It was also found that the more resistant the strains were to antimicrobials, the lower the carriage of virulence genes detected. The biofilm content was measured using the semi-quantitative crystal violet method. It was found that there were a few strains with medium or strong biofilm-forming abilities. However, the number of virulence genes carried by the 63 strains of Pseudomonas aeruginosa was inversely proportional to the biofilm-forming ability. It was also found that there were significantly more Pseudomonas aeruginosa in the biofilm state than in the planktonic state and that strains with strong biofilm-forming abilities were more resistant to antimicrobials.},
}

@article {pmid39594124,
year = {2024},
author = {Hu, M and Zhou, Z and Liu, C and Zhan, Z and Cui, Y and He, S and Shi, X},
title = {Roles of Response Regulators in the Two-Component System in the Formation of Stress Tolerance, Motility and Biofilm in Salmonella Enteritidis.},
journal = {Foods (Basel, Switzerland)},
volume = {13},
number = {22},
pages = {},
pmid = {39594124},
issn = {2304-8158},
support = {32172316//National Natural Science Foundation of China/ ; 2023M742281//China Postdoctoral Science Foundation/ ; },
abstract = {Two-component systems (TCS) of Salmonella enterica serovar Enteritidis are composed of a histidine kinase and a response regulator (RR) and represent a critical mechanism by which bacteria develop resistance to environmental stress. Here, we characterized the functions of RRs in TCS in the formation of stress tolerance, motility and biofilm using twenty-six S. Enteritidis RR-encoding gene deletion mutants. The viability results unraveled their essential roles in resistance to elevated temperature (GlrR), pH alterations (GlrR, TctD, YedW, ArcA and YehT), high salt (PhoB, BaeR, CpxR, PhoP, UvrY and TctD), oxidative stress (PhoB, YedW, BaeR, ArcA, PhoP, UvrY, PgtA and QseB) and motility (ArcA, GlnG, PgtA, PhoB, UhpA, OmpR, UvrY and QseB) of S. Enteritidis. The results of the crystal violet staining, microscopy observation and Congo red binding assays demonstrated that the absence of ArcA, GlnG, PhoP, OmpR, ZraR or SsrB in S. Enteritidis led to a reduction in biofilms and an impairment in red/dry/rough macrocolony formation, whereas the absence of UvrY exhibited an increase in biofilms and formed a brown/smooth/sticky macrocolony. The results indicated the regulatory effects of these RRs on the production of biofilm matrix, curli fimbriae and cellulose. Our findings yielded insights into the role of TCSs, making them a promising target for combating S. Enteritidis.},
}

@article {pmid39593330,
year = {2024},
author = {Rodrigues Carneiro, C and Nogueira Leite, N and de Abreu Oliveira, AV and Dos Santos Oliveira, M and Wischral, D and Renon Eller, M and Gonçalves Machado, S and de Oliveira, EB and Edgard Luera Pena, W},
title = {Mathematical modeling for the prediction of biofilm formation and removal in the food industry as strategy to control microbiological resistance.},
journal = {Food research international (Ottawa, Ont.)},
volume = {197},
number = {Pt 1},
pages = {115248},
doi = {10.1016/j.foodres.2024.115248},
pmid = {39593330},
issn = {1873-7145},
mesh = {*Biofilms/growth & development ; *Food Microbiology ; *Models, Theoretical ; Food Industry ; Food Handling/methods ; Food Contamination/prevention & control ; Food Safety ; Bacterial Adhesion ; },
abstract = {The formation of biofilms in the food industry poses significant economic, social, and public health challenges. Concurrently, mathematical models have emerged as promising tools for investigating microbial contamination and biofilm dynamics. This study evaluates the application of these models, highlighting their ability to identify critical parameters influencing microbial adhesion and to develop strategies for disrupting biofilm formation. Furthermore, it explores how mathematical modeling can address current limitations in food safety, discussing practical challenges such as the complexity of biological systems and the necessity for experimental validation of proposed models. In this context, the review assesses both the potential and the challenges associated with employing mathematical models for microbial control in food processing, examining the specifics of existing models. Additionally, it underscores the need for a comprehensive understanding of biofilm formation mechanisms and control techniques to fully leverage the benefits of these models. The findings demonstrate that mathematical modeling is a viable, innovative, and promising approach for optimizing biofilm prevention and control strategies in the food industry. To achieve more effective biofilm management and ensure consumer food safety, future research should focus on applying these models to various real-world scenarios.},
}

*Biofilms/growth & development
*Food Microbiology
*Models, Theoretical
Food Industry
Food Handling/methods
Food Contamination/prevention & control
Food Safety
Bacterial Adhesion

@article {pmid39593289,
year = {2024},
author = {Anamul Hasan Chowdhury, M and Ashrafudoulla, M and Isaïe Ulrich Mevo, S and Mahamud, AGMSU and Sanat Anjum Reem, C and Jie-Won Ha, A and Ha, SD},
title = {Efficacy of orange terpene against Escherichia coli biofilm on beef and food contact surfaces.},
journal = {Food research international (Ottawa, Ont.)},
volume = {197},
number = {Pt 1},
pages = {115204},
doi = {10.1016/j.foodres.2024.115204},
pmid = {39593289},
issn = {1873-7145},
mesh = {*Biofilms/drug effects/growth & development ; *Escherichia coli/drug effects ; *Stainless Steel ; *Food Microbiology ; *Red Meat/microbiology ; *Terpenes/pharmacology ; Animals ; *Microbial Sensitivity Tests ; Cattle ; Anti-Bacterial Agents/pharmacology ; Citrus sinensis/chemistry ; Polyethylene Terephthalates/chemistry ; Rubber ; Polyethylene/chemistry ; Humans ; Food Contamination/prevention & control ; },
abstract = {Foodborne pathogen Escherichia coli frequently causes foodborne infections. In our study, we investigated the antibiofilm activity of orange terpene (OT) against E. coli biofilms on a food surface (beef) and different surfaces that come into touch with food, including stainless steel (SS), polyethylene terephthalate (PET), low-density polyethylene (LDPE), and rubber (SR). The study findings revealed that OT significantly (P < 0.05) eliminated 48-h-old biofilms from all food contact surfaces (SS: 2.09 log CFU/cm[2], PET: 1.95 log CFU/cm[2], LDPE: 1.94 log CFU/cm[2], and SR: 1.4 log CFU/cm[2]). Additionally, on beef surfaces, OT at a minimum inhibitory concentration (MIC) of 0.13 % demonstrated the ability to inhibit biofilm development by approximately 1.5 log CFU/cm[2] and reduced pre-formed biofilms by 2.02 log CFU/cm[2]. Our sensory evaluations showed that it had no adverse impacts on beef color and texture, although it slightly altered the natural odor of beef. Quantitative and qualitative assessments showed that OT has strong bactericidal actions on biofilm populations. It significantly altered cell surface hydrophobicity, reduced cellular ATP levels, and inhibited cell auto-aggregation in planktonic cells (P < 0.05). As a result, our findings emphasize the antibacterial potentiality of OT in reducing the biofilm of E. coli in the food sector.},
}

*Biofilms/drug effects/growth & development
*Escherichia coli/drug effects
*Stainless Steel
*Food Microbiology
*Red Meat/microbiology
*Terpenes/pharmacology
Animals
*Microbial Sensitivity Tests
Cattle
Anti-Bacterial Agents/pharmacology
Citrus sinensis/chemistry
Polyethylene Terephthalates/chemistry
Rubber
Polyethylene/chemistry
Humans
Food Contamination/prevention & control

@article {pmid39592778,
year = {2024},
author = {Sur, S and Sathiavelu, M},
title = {Functional profiling of the rhizospheric Exiguobacterium sp. for dimethoate degradation, PGPR activity, biofilm development, and ecotoxicological risk.},
journal = {Scientific reports},
volume = {14},
number = {1},
pages = {29361},
pmid = {39592778},
issn = {2045-2322},
mesh = {*Dimethoate/toxicity/metabolism ; *Biofilms/drug effects/growth & development ; *Biodegradation, Environmental ; *Rhizosphere ; Soil Microbiology ; Gas Chromatography-Mass Spectrometry ; Indoleacetic Acids/metabolism ; Soil Pollutants/toxicity/metabolism ; Hydrogen Cyanide/metabolism ; Ammonia/metabolism ; Ecotoxicology ; Hexachlorocyclohexane/metabolism ; },
abstract = {This study introduces an indigenous bacterial strain, Exiguobacterium sp. (L.O), isolated from sugarcane fields in Sevur, Tamil Nadu, which has adapted to prolonged exposure to dimethoate. The strain demonstrated the capability to utilize 150 ppm of dimethoate as its sole carbon source, achieving a remarkable degradation rate of 95.87% within 5 days in mineral salt media. Gas chromatography-mass spectrometry (GC-MS) analyses identified the presence of intermediate by-products formed during degradation, like methyl diethanol amine and aspartyl glycine ethyl ester. Notably, phosphorothioic O, O, S-acid, an expected end product in the degradation of dimethoate, was also identified, further confirming the strain's effective metabolic breakdown of the pesticide. Further degradation study and analysis of changes in functional group was performed by FTIR, and a hypothetical degradation pathway was elucidated showing the course of dimethoate metabolism by the strain. Exiguobacterium sp. (L.O) also displayed significant plant growth-promoting traits, including the production of HCN, IAA, and ammonia and the formation of biofilms, which enhance its utility in agricultural applications. The ecotoxicity study revealed the degradation by-products exhibited reduced toxicity compared to the parent compound dimethoate, highlighting the strain's potential not only for bioremediation but also for supporting sustainable agricultural practices. This research presents a novel application of Exiguobacterium sp. (L.O), integrating the bioremediation of the organophosphate pesticide dimethoate with agricultural enhancement. This approach is critical for addressing the challenges associated with pesticide pollution in agricultural practices. This study is likely the first to demonstrate the application of this strain in the degradation of dimethoate, as suggested by an extensive review of the literature.},
}

*Dimethoate/toxicity/metabolism
*Biofilms/drug effects/growth & development
*Biodegradation, Environmental
*Rhizosphere
Soil Microbiology
Gas Chromatography-Mass Spectrometry
Indoleacetic Acids/metabolism
Soil Pollutants/toxicity/metabolism
Hydrogen Cyanide/metabolism
Ammonia/metabolism
Ecotoxicology
Hexachlorocyclohexane/metabolism

@article {pmid39590782,
year = {2024},
author = {Domingos, LTS and de Moraes, DC and Santos, MFC and Curvelo, JAR and Bayona-Pacheco, B and Marquez, EA and Martinez, AWB and Berlinck, RGS and Ferreira-Pereira, A},
title = {Batzelladine D, a Marine Natural Product, Reverses the Fluconazole Resistance Phenotype Mediated by Transmembrane Transporters in Candida albicans and Interferes with Its Biofilm: An In Vitro and In Silico Study.},
journal = {Marine drugs},
volume = {22},
number = {11},
pages = {},
pmid = {39590782},
issn = {1660-3397},
mesh = {*Biofilms/drug effects ; *Fluconazole/pharmacology ; *Candida albicans/drug effects ; *Drug Resistance, Fungal/drug effects ; *Antifungal Agents/pharmacology ; Animals ; *Caenorhabditis elegans/drug effects/microbiology ; *Saccharomyces cerevisiae/drug effects ; Membrane Transport Proteins/metabolism/genetics/drug effects ; Biological Products/pharmacology ; Microbial Sensitivity Tests ; Phenotype ; Computer Simulation ; Fungal Proteins/metabolism/genetics ; },
abstract = {Numerous Candida species are responsible for fungal infections; however, Candida albicans stands out among the others. Treatment with fluconazole is often ineffective due to the resistance phenotype mediated by transmembrane transporters and/or biofilm formation, mechanisms of resistance commonly found in C. albicans strains. A previous study by our group demonstrated that batzelladine D can inhibit the Pdr5p transporter in Saccharomyces cerevisiae. In the present study, our aim was to investigate the efficacy of batzelladine D in inhibiting the main efflux pumps of Candida albicans, CaCdr1p and CaCdr2p, as well as to evaluate the effect of the compound on C. albicans biofilm. Assays were conducted using a clinical isolate of Candida albicans expressing both transporters. Additionally, to allow the study of each transporter, S. cerevisiae mutant strains overexpressing CaCdr1p or CaCdr2p were used. Batzelladine D was able to reverse the fluconazole resistance phenotype by acting on both transporters. The compound synergistically improved the effect of fluconazole against the clinical isolate when tested in the Caenorhabditis elegans animal model. Moreover, the compound disrupted the preformed biofilm. Based on the obtained data, the continuation of batzelladine D studies as a potential new antifungal agent and/or chemosensitizer in Candida albicans infections can be suggested.},
}

*Biofilms/drug effects
*Fluconazole/pharmacology
*Candida albicans/drug effects
*Drug Resistance, Fungal/drug effects
*Antifungal Agents/pharmacology
Animals
*Caenorhabditis elegans/drug effects/microbiology
*Saccharomyces cerevisiae/drug effects
Membrane Transport Proteins/metabolism/genetics/drug effects
Biological Products/pharmacology
Microbial Sensitivity Tests
Phenotype
Computer Simulation
Fungal Proteins/metabolism/genetics

@article {pmid39590685,
year = {2024},
author = {Zhang, R and Wiederhold, N and Calderone, R and Li, D},
title = {Biofilm Formation in Clinical Isolates of Fusarium.},
journal = {Journal of fungi (Basel, Switzerland)},
volume = {10},
number = {11},
pages = {},
pmid = {39590685},
issn = {2309-608X},
abstract = {Many microbial pathogens form biofilms, assemblages of polymeric compounds that play a crucial role in establishing infections. The biofilms of Fusarium species also contribute to high antifungal resistance. Using our collection of 29 clinical Fusarium isolates, we focused on characterizing differences in thermotolerance, anaerobic growth, and biofilm formation across four Fusarium species complexes commonly found in clinical settings. We investigated the role of carbon sources, temperature, and fungal morphology on biofilm development. Using fluorescence microscopy, we followed the stages of biofilm formation. Biofilms were screened for sensitivity/resistance to the antifungals voriconazole (VOR), amphotericin B (AmB), and 5-fluorocytosine (5-FC). Our findings revealed generally poor thermotolerance and growth under anaerobic conditions across all Fusarium species. VOR was more effective than AmB in controlling biofilm formation, but the combination of VOR, AmB, and 5-FC significantly reduced biofilm formation across all species. Additionally, Fusarium biofilm formation varied under non-glucose carbon sources, highlighting the species' adaptability to different nutrient environments. Notably, early stage biofilms were primarily composed of lipids, while polysaccharides became dominant in late-stage biofilms, suggesting a dynamic shift in biofilm composition over time.},
}

@article {pmid39590365,
year = {2024},
author = {Khan, MA and Azam, M and Younus, H},
title = {In Silico and In Vitro Studies to Explore the Effect of Thymoquinone on Isocitrate Lyase, Biofilm Formation, and the Expression of Some Virulence Genes in Candida albicans.},
journal = {Current issues in molecular biology},
volume = {46},
number = {11},
pages = {12951-12967},
pmid = {39590365},
issn = {1467-3045},
support = {2023-SDG-I-HMSRC-36570//Qassim University, represented by the Deanship of Scientific Research/ ; },
abstract = {Thymoquinone (TQ), a bioactive compound from black cumin (Nigella sativa), has demonstrated a broad range of therapeutic effects. The aim of this study is to evaluate the antifungal efficacy of TQ by targeting key virulence factors in Candida albicans, specifically focusing on isocitrate lyase (ICL) activity, biofilm formation, and gene expression. This study explored TQ's impact on ICL, a decisive enzyme in the glyoxylate cycle, along with its effect on hyphal formation, biofilm development, and the virulent gene expression of C. albicans through in silico and in vitro studies. Molecular docking revealed a binding energy of -6.4 kcal/mol between TQ and ICL, indicating moderate affinity. The stability of the ICL-TQ complex was validated through 50 ns molecular dynamics simulations, showing the root mean square deviation (RMSD) values of 0.35 nm for ICL and 0.38 nm for the complex. In vitro studies further validated these findings, showing a dose-dependent inhibition of ICL activity. TQ at 2 µg/mL reduced enzyme activity by 57%, and at 4 µg/mL, by 91.4%. Additionally, TQ disrupted the yeast-to-hyphae switch, a key virulence factor, with 1 and 2 µg/mL doses significantly inhibiting hyphal formation. The biofilm formation was similarly affected, with a 58% reduction at 2 µg/mL and an 83% reduction at 4 µg/mL. TQ also downregulated the ALS1 and HWP1 genes that are associated with adhesion and biofilm development, demonstrating its broad-spectrum antifungal activity. These findings suggest that TQ is a promising candidate for antifungal therapies, targeting multiple virulence factors in C. albicans and potentially overcoming biofilm-associated drug resistance. Future research should focus on in vivo validation, optimization for clinical applications, and expanding its spectrum against other drug-resistant fungal species.},
}

@article {pmid39590364,
year = {2024},
author = {Emeka, PM and Badger-Emeka, LI and Thirugnanasambantham, K},
title = {Virtual Screening and Meta-Analysis Approach Identifies Factors for Inversion Stimulation (Fis) and Other Genes Responsible for Biofilm Production in Pseudomonas aeruginosa: A Corneal Pathogen.},
journal = {Current issues in molecular biology},
volume = {46},
number = {11},
pages = {12931-12950},
pmid = {39590364},
issn = {1467-3045},
support = {KSRG-2023-107//King Salman center For Disability Research/ ; },
abstract = {Bacterial keratitis caused by Pseudomonas aeruginosa is indeed a serious concern due to its potential to cause blindness and its resistance to antibiotics, partly attributed to biofilm formation and cytotoxicity to the cornea. The present study uses a meta-analysis of a transcriptomics dataset to identify important genes and pathways in biofilm formation of P. aeruginosa induced keratitis. By combining data from several studies, meta-analysis can enhance statistical power and robustness, enabling the identification of 83 differentially expressed candidate genes, including fis that could serve as therapeutic targets. The approach of combining meta-analysis with virtual screening and in vitro methods provides a comprehensive strategy for identifying potential target genes and pathways crucial for bacterial biofilm formation and development anti-biofilm medications against P. aeruginosa infections. The study identified 83 candidate genes that exhibited differential expression in the biofilm state, with fis proposed as an ideal target for therapy for P. aeruginosa biofilm formation. These techniques, meta-analysis, virtual screening, and invitro methods were used in combination to diagnostically identify these genes, which play a significant role in biofilms. This finding has highlighted a hallmark target list for P. aeruginosa anti-biofilm potential treatments.},
}

@article {pmid39589820,
year = {2024},
author = {Babeer, A and Liu, Y and Ren, Z and Xiang, Z and Oh, MJ and Pandey, NK and Simon-Soro, A and Huang, R and Karabucak, B and Cormode, DP and Chen, C and Koo, H},
title = {Ferumoxytol nanozymes effectively target chronic biofilm infections in apical periodontitis.},
journal = {The Journal of clinical investigation},
volume = {},
number = {},
pages = {},
doi = {10.1172/JCI183576},
pmid = {39589820},
issn = {1558-8238},
abstract = {Bacterial biofilms are pervasive and recalcitrant to current antimicrobials, causing numerous infections. Iron oxide-nanozymes, including an FDA-approved formulation (ferumoxytol, FMX), show potential against biofilm infections via catalytic activation of hydrogen peroxide (H2O2). However, clinical evidence on its efficacy and therapeutic mechanisms is lacking. Here, we investigate whether FMX-nanozymes can treat chronic biofilm infections and compare their bioactivity to gold-standard sodium hypochlorite (NaOCl), a potent but caustic disinfectant. Clinical performance was assessed in patients with apical periodontitis, an intractable endodontic infection affecting half of the global adult population. Data show robust antibiofilm activity by a single application of FMX with H2O2 achieving results comparable to NaOCl without adverse effects. FMX binds efficiently to bacterial pathogens Enterococcus faecalis and Fusobacterium nucleatum and remains catalytically active without being affected by dental tissues. This allows for effective eradication of endodontic biofilms via on-site free-radical generation without inducing cytotoxicity. Unexpectedly, FMX promotes growth of stem cells of apical papilla (SCAP), with transcriptomic analyses revealing upregulation of proliferation-associated pathways and downregulation of cell-cycle suppressor genes. Notably, FMX activates SCAP pluripotency and WNT/NOTCH signaling that induces its osteogenic capacity. Together, we show FMX nanozymes are clinically effective against severe chronic biofilm infection with pathogen targeting and unique stem cell-stimulatory properties, offering a regenerative approach to antimicrobial therapy.},
}

@article {pmid39589773,
year = {2024},
author = {Titouche, Y and Akkou, M and Djaoui, Y and Chergui, A and Mechoub, D and Bentayeb, L and Fatihi, A and Nia, Y and Hennekinne, JA},
title = {Investigation of Biofilm Formation Ability and Antibiotic Resistance of Staphylococcus aureus Isolates from Food Products.},
journal = {Foodborne pathogens and disease},
volume = {},
number = {},
pages = {},
doi = {10.1089/fpd.2024.0121},
pmid = {39589773},
issn = {1556-7125},
abstract = {Staphylococcus aureus is one of the major causes of foodborne diseases and its presence in food products may poses a public health challenge. The aims of this study were to assess in vitro the capacity of S. aureus isolates from foods to form biofilm and to determine their antibiotic susceptibility. A total of 80 S. aureus isolates were characterized. The slime production ability was evaluated by congo-red agar (CRA) and the biofilm formation was carried out by microtiter-plate method (MPM). Resistance of isolates to eight antibiotics was determined using disc diffusion method. Sixty-four (80%) of the isolates were slime producers on congo-red agar. However, all isolates were biofilm producers on microtiter-plate method. The highest resistance profiles were ascribed to penicillin G (91.25%) and tetracycline (41.25%). Twelve isolates were methicillin-resistant (MRSA) harboring the mecA gene. All of these MRSA isolates were negative for the genes of the Panton Valentine leukocidine (lukF/S-PV). Typing of the MRSA isolates indicated that they belonged to three spa-types including t024, t450 and t688. The presence of biofilm producers and multidrug resistant isolates (MRSA) in food samples can represent a risk for public health. Therefore, an efficient control and effective measures were needed along the production chain to ensure the food safety.},
}

@article {pmid39589428,
year = {2024},
author = {Liu, Y and Fang, B and Wuri, G and Lan, H and Wang, R and Sun, Y and Zhao, W and Hung, WL and Zhang, M},
title = {From Biofilm to Breath: The Role of Lacticaseibacillus paracasei ET-22 Postbiotics in Combating Oral Malodor.},
journal = {Journal of agricultural and food chemistry},
volume = {},
number = {},
pages = {},
doi = {10.1021/acs.jafc.4c07381},
pmid = {39589428},
issn = {1520-5118},
abstract = {Previous studies demonstrated that sufferers with halitosis can be significantly improved with Lacticaseibacillus paracasei ET-22 (ET-22) postbiotics intervention. The objectives of this investigation were to identify the primary components responsible for inhibiting oral malodor. This study demonstrated that cell-free supernatants (CFSs) were more effective in inhibiting production of volatile sulfur compounds (VSCs). Untargeted metabolomics identified CFSs as primarily consisting of organic acids, lipids, peptides, and nucleotides. Among the potential active components, phenyllactic acid (PLA) and peptide GP(Hyp)GAG significantly inhibited microbial-induced VSCs production, with VSC concentrations reduced by 42.7% and 44.6%, respectively. Given the correlation between biofilms and halitosis, microstructural changes in biofilms were examined. PLA suppressed the biomass of the biofilm by 41.7%, while the biofilm thickness was reduced from 202.3 to 70.0 μm. GP(Hyp)GAG intervention reduced the abundance of Fusobacterium nucleatum and Streptococcus mutans within the biofilm, and the expression of biofilm-forming genes FadA and Gtfb were also suppressed by 41.8% and 59.4%. Additionally, the VSC production capacities were reduced due to the decrease in VSC producing bacteria (F. nucleatum, Prevotella intermedia, and Solobacterium moorei) and down-regulation of Cdl and Mgl genes. Collectively, the current study proved that PLA and GP(Hyp)GAG may be the main contributors to halitosis inhibition by ET-22 postbiotics.},
}

@article {pmid39589111,
year = {2024},
author = {Mu, K and He, M and Chen, H and Liu, T and Fan, Y and Tao, Y and Feng, H and Huang, Q and Xiao, Y and Chen, W},
title = {Tetracycline induces wsp operon expression to promote biofilm formation in Pseudomonas putida.},
journal = {Applied and environmental microbiology},
volume = {},
number = {},
pages = {e0107124},
doi = {10.1128/aem.01071-24},
pmid = {39589111},
issn = {1098-5336},
abstract = {The overuse and wanton discharge of antibiotics produces a threat to bacteria in the environment, which, in turn, stimulates the more rapid emergence of antibiotic-resistant bacteria. Pseudomonas putida actively forms biofilms to protect the population under tetracycline stress, but the molecular mechanism remains unclear. This study found that tetracycline at sub-minimal inhibitory concentrations increased cyclic diguanylate (c-di-GMP), a second messenger that positively regulates biofilm formation. Four c-di-GMP-metabolizing proteins were found to be involved in the tetracycline-mediated biofilm promotion, including DibA, WspR, PP_3242, and PP_3319. Among them, the diguanylate cyclase WspR displayed the most significant effect on c-di-GMP level and biofilm formation. WspR belongs to the wsp operon comprising seven genes (wspA-wspF and wspR). The wsp operon contained six promoters, including one major start promoter (PwspA) and five internal promoters (PwspB, PwspC, PwspD, PwspF, and PwspR), and tetracycline promoted the activity of PwspA. The stress-response sigma factor RpoS directly bound to PwspA and positively regulated its activity under tetracycline stress. Moreover, RpoS was required for tetracycline to induce PwspA activity and promote biofilm formation. Our results enrich the transcriptional regulation of the wsp operon and reveal the mechanism by which tetracycline promotes biofilm formation in P. putida.IMPORTANCEThe overuse and wanton discharge of antibiotics produces a threat to bacteria in the environment, which, in turn, stimulates the more rapid emergence of antibiotic-resistant bacteria. The Pseudomonas putida actively forms biofilm against antibiotic threats, but the mechanism remains unclear. Here, our results showed that tetracycline treatment at sub-minimal inhibitory concentrations could induce the expression of the Wsp system via the sigma factor RpoS in P. putida, resulting in elevated c-di-GMP levels, which leads to increased biofilm formation. The wsp operon contains one major promoter and five internal promoters, and RpoS directly binds to the major promoter to promote its activity.},
}

@article {pmid39589067,
year = {2024},
author = {Popczyk, P and Ghinet, A and Bortolus, C and Kamus, L and Lensink, MF and de Ruyck, J and Sendid, B and Dubar, F},
title = {Antifungal and anti-biofilm effects of hydrazone derivatives on Candida spp.},
journal = {Journal of enzyme inhibition and medicinal chemistry},
volume = {39},
number = {1},
pages = {2429109},
doi = {10.1080/14756366.2024.2429109},
pmid = {39589067},
issn = {1475-6374},
mesh = {*Biofilms/drug effects ; *Antifungal Agents/pharmacology/chemistry/chemical synthesis ; *Hydrazones/pharmacology/chemistry/chemical synthesis ; *Candida/drug effects ; *Microbial Sensitivity Tests ; Structure-Activity Relationship ; *Dose-Response Relationship, Drug ; Molecular Structure ; Animals ; Humans ; },
abstract = {Worldwide, invasive candidiasis are a burden for the health system due to difficulties to manage patients, to the increasing of the resistance of the current therapeutics and the emergence of naturally resistant species of Candida. In this context, the development of innovative antifungal drugs is urgently needed. During invasive candidiasis, yeast is submitted to many stresses (oxidative, thermic, osmotic) in the human host. In order to resist in this context, yeast develops different strategy, especially the biosynthesis of trehalose. Starting from the 3D structural data of TPS2, an enzyme implicated in trehalose biosynthesis, we identified hydrazone as an interesting scaffold to design new antifungal drugs. Interestingly, our hydrazone derivatives which demonstrate antifungal and anti-biofilm effects on Candida spp., are non-toxic in in vitro and in vivo models (Galleria mellonella).},
}

*Biofilms/drug effects
*Antifungal Agents/pharmacology/chemistry/chemical synthesis
*Hydrazones/pharmacology/chemistry/chemical synthesis
*Candida/drug effects
*Microbial Sensitivity Tests
Structure-Activity Relationship
*Dose-Response Relationship, Drug
Molecular Structure
Animals
Humans

@article {pmid39588812,
year = {2024},
author = {Frison, SS and Borges, EL and Guedes, ACM and Honorato-Sampaio, K},
title = {Biofilm and Its Characteristics in Venous Ulcers.},
journal = {Journal of wound, ostomy, and continence nursing : official publication of The Wound, Ostomy and Continence Nurses Society},
volume = {51},
number = {6},
pages = {445-453},
pmid = {39588812},
issn = {1528-3976},
mesh = {Humans ; *Biofilms ; *Varicose Ulcer/microbiology/physiopathology ; Male ; Female ; Aged ; Middle Aged ; Brazil ; Wound Healing/physiology ; Aged, 80 and over ; Pseudomonas aeruginosa/pathogenicity ; Adult ; },
abstract = {PURPOSE: The aim of the study was to analyze the characteristics of the biofilm of venous ulcers in terms of location and formation and to relate the presence of the biofilm to ulcer characteristics including duration, injured area, and necrotic tissue.

DESIGN: Descriptive clinical study.

MATERIALS AND METHODS: We obtained 2 biopsy fragments (tissue samples) from 44 patients with venous ulcers treated at a public outpatient clinic in a university hospital in Belo Horizonte, Brazil. Ulcers were photographed and classified according to the duration. In addition, the wound size and proportion of wound surface covered by necrotic tissue were measured. One fragment from each ulcer underwent microbiological analysis, while the other was analyzed using transmission electron microscopy. Data analysis was limited to fragments from patients with bacteria in the microbiological analysis.

RESULTS: Data analysis is based on samples obtained from 21 ulcers in 21 patients who had bacteria in their ulcer based on microbiologic analysis of a tissue sample. Most ulcers were open for 2 to 10 years, 57% (n = 12) were 16 cm2 or smaller, and the proportion of the wound bed covered by necrotic tissue coverage varied widely. Of the 21/44 patients (48%) with bacteria in their ulcers, only 3 patients had bacterial biofilm present in the transmission electron microscopy, corresponding to 7% of the 44 patients. Pseudomonas aeruginosa was the most frequent bacterium, identified in 10 fragments. The biofilm was not present on the surface but in a layer slightly below it. The detection of biofilms was not directly related to the duration of the ulcer. It was not possible to establish a correlation between the size of the lesion and the presence of these microorganisms due to the small sample size.

CONCLUSIONS: Our findings indicate that detecting biofilm in venous ulcers is challenging, as it does not uniformly occur throughout the wound bed, can occur at different depths, and is often not present on the wound surface. There is a need to develop studies that can contribute to the detection of biofilm in clinical practice.},
}

Humans
*Biofilms
*Varicose Ulcer/microbiology/physiopathology
Male
Female
Aged
Middle Aged
Brazil
Wound Healing/physiology
Aged, 80 and over
Pseudomonas aeruginosa/pathogenicity
Adult

@article {pmid39588362,
year = {2024},
author = {Debener, N and Heine, N and Legutko, B and Denkena, B and Prasanthan, V and Frings, K and Torres-Mapa, ML and Heisterkamp, A and Stiesch, M and Doll-Nikutta, K and Bahnemann, J},
title = {Optically accessible, 3D-printed flow chamber with integrated sensors for the monitoring of oral multispecies biofilm growth in vitro.},
journal = {Frontiers in bioengineering and biotechnology},
volume = {12},
number = {},
pages = {1483200},
pmid = {39588362},
issn = {2296-4185},
abstract = {The formation of pathogenic multispecies biofilms in the human oral cavity can lead to implant-associated infections, which may ultimately result in implant failure. These infections are neither easily detected nor readily treated. Due to high complexity of oral biofilms, detailed mechanisms of the bacterial dysbiotic shift are not yet even fully understood. In order to study oral biofilms in more detail and develop prevention strategies to fight implant-associated infections, in vitro biofilm models are sorely needed. In this study, we adapted an in vitro biofilm flow chamber model to include miniaturized transparent 3D-printed flow chambers with integrated optical pH sensors - thereby enabling the microscopic evaluation of biofilm growth as well as the monitoring of acidification in close proximity. Two different 3D printing materials were initially characterized with respect to their biocompatibility and surface topography. The functionality of the optically accessible miniaturized flow chambers was then tested using five-species biofilms (featuring the species Streptococcus oralis, Veillonella dispar, Actinomyces naeslundii, Fusobacterium nucleatum, and Porphyromonas gingivalis) and compared to biofilm growth on titanium specimens in the established flow chamber model. As confirmed by live/dead staining and fluorescence in situ hybridization via confocal laser scanning microscopy, the flow chamber setup proved to be suitable for growing reproducible oral biofilms under flow conditions while continuously monitoring biofilm pH. Therefore, the system is suitable for future research use with respect to biofilm dysbiosis and also has great potential for further parallelization and adaptation to achieve higher throughput as well as include additional optical sensors or sample materials.},
}

@article {pmid39587976,
year = {2024},
author = {Yan, N and Zhou, H and Jin, P and Li, T and Liu, Q and Ning, H and Ma, Z and Feng, L and Jin, T and Deng, Y and Wu, Z},
title = {A Multifunctional Cobalt-Containing Implant for Treating Biofilm Infections and Promoting Osteointegration in Infected Bone Defects Through Macrophage-Mediated Immunomodulation.},
journal = {Advanced science (Weinheim, Baden-Wurttemberg, Germany)},
volume = {},
number = {},
pages = {e2409200},
doi = {10.1002/advs.202409200},
pmid = {39587976},
issn = {2198-3844},
support = {JL06120001H//Joint Laboratory of Plasma Application Technology Funding/ ; R2023063//Hunan Provincial Health High-Level Talent Scientific Research Project/ ; },
abstract = {Treating bone infections and ensuring bone recovery is one of the major global problems facing modern orthopedics. Prolonged antibiotic use may increase the risk of antimicrobial resistance, and inflammation caused by biofilms can obstruct tissue healing, making bone infection treatment even more challenging. The optimal treatment strategy combines immune response modification to promote osteogenesis with effective bacterial infection removal that does not require long-term antibiotic use. A one-step plasma immersion ion implantation approach is used to create titanium alloy implants incorporating cobalt. According to experimental findings, cobalt-containing titanium implants exhibit improved antibacterial activity by efficiently disrupting biofilm formations and reducing Methicillin-resistant Staphylococcus aureus adherence by over 80%. Additionally, the implants exhibit superior anti-inflammatory and osseointegration properties. RNA sequencing analysis reveals the potential mechanism of Co[2+] in regulating the polarization of macrophages toward the anti-inflammatory M2 phenotype, which is crucial for creating an immune environment conducive to bone healing. Concurrently, these implants promote osteogenic differentiation while suppressing osteoclast activity, further supporting bone repair. Overall, without exogenous recombinant proteins or antibiotics, the implants effectively eradicate infections and expedite bone repair, offering a novel therapeutic strategy for complex skeletal diseases with clinical promise.},
}

@article {pmid39586542,
year = {2024},
author = {Wu, J and Thompson, TP and O'Connell, NH and McCracken, K and Powell, J and Gilmore, BF and Dunne, CP and Kelly, SA},
title = {Extended-Spectrum β-Lactamase-Producing Bacteria from Hospital Wastewater Pipes: Isolation, Characterisation, and Biofilm Control using Common Disinfectants.},
journal = {The Journal of hospital infection},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.jhin.2024.11.013},
pmid = {39586542},
issn = {1532-2939},
abstract = {Hospital wastewater systems have been identified as reservoirs for antibiotic-resistant bacteria, with biofilms harbouring extended-spectrum β-lactamase (ESBL)-producing microorganisms posing significant infection risk. This study focuses on the antimicrobial susceptibility and biofilm control of ESBL-producing bacteria from wastewater pipes from a tertiary care teaching hospital in Ireland, which had experienced endemic infection outbreaks caused by ESBL-producing bacteria. Following isolation of ESBL-producers on selective agar antibiotic susceptibility profiles were determined for a number of antibiotics assessed for their ability to form biofilms. Biofilm eradication studies using the commercially available disinfectants bleach, Optizan[TM], Virkon[TM], and Clinell[TM] were performed on selected isolates. ESBL-producing bacteria (n=39 isolates) showed a high degree of resistance to β-lactams. Biofilm-forming ability ranged from non-adherent to strongly adherent and appeared to be source dependent, suggesting the characteristics of the pipe environment played an important role in biofilm formation. All disinfectants showed effective biofilm eradication under suggested working conditions. Effectiveness was significantly reduced following reductions in concentration and contact time, with only Clinell[TM] showing significant biofilm reduction against all isolates at all concentrations and contact times tested. Of the chlorine-based formulations, Optizan[TM] frequently outperformed bleach at lower concentrations and treatment times. Biofilm eradication was strain dependent, with varying disinfectant response profiles observed from biofilms from different Stenotrophomonas maltophilia isolates. This study highlights the high degree of ESBL-producing bacteria recovery from patient-facing hospital wastewater apparatus. Their ability to form resident biofilms and act as potential reservoirs of infection emphasises the need for rigorous and effective infection control practices.},
}

@article {pmid39586513,
year = {2024},
author = {Abdullah, HD and Kamal, I and Sabry, SA and Elghany, MA and Hakim Ramadan, AE},
title = {Effective tailoring of cefepime into bilosomes: A promising nanoplatform for enhancing oral absorption, extending half-life, and evaluating biocompatibility, antibacterial, anti-biofilm, anti-breast cancer activity, ex-vivo, and in-vivo studies.},
journal = {International journal of pharmaceutics},
volume = {},
number = {},
pages = {125001},
doi = {10.1016/j.ijpharm.2024.125001},
pmid = {39586513},
issn = {1873-3476},
abstract = {The clinical implication of cefepime HCl (CEF) is compromised owing to restricted oral bioavailability and harmful adverse effects without any authorized oral formulation available. The present investigation provides an innovative sustained-release oral drug delivery strategy that tackles the challenges of limited oral bioavailability and prolongs the half-life of CEF. Accordingly, CEF was loaded into a bilosome, a liposome or noisome-based vesicle employing bile salt as a permeation enhancer. Despite its hydrophilic nature, the drug was effectively loaded into bilosomes. Nine various formulas were fabricated by a reverse phase evaporation method. The resulting vesicles increased the encapsulation efficiency (EE %) from 39.31 ± 0.03 % to 63.09 ± 0.01 %, drug loading capacity (DLC %) from 6.99 ± 0.25 to 42.91 ± 0.11 %, the particle size (PS) from 264 ± 13.52 nm to 405.40 ± 8.91 nm, and the polydispersity index (PDI) values ranged from 0.243 ± 0.040 to 0.430 ± 0.050. The zeta potential (ZP) changed from - 35.67 ± 3.73 mV to - 62.21 ± 2.21 mV. Further, the release profile exhibited dual release pattern within 24 h, with the percentage of release (CR %) expanding from 42 ± 0.13 % to 69.16 ± 0.09 %. The selected formula was found to be B3 with EE % = 56.61 ± 0.02 %, PS = 264 ± 13.52 nm, ZP = - 62.21 ± 2.21 mV, PDI = 0.430 ± 0.050, CR % = 52.94 ± 0.06 %, and IC50 of 3.4 ± 0.40 µg/ml against MCF-7 cells with scattered spherical non-agglomerated vesicles. Additionally, it exhibited higher anti-MRSA biofilm, relative bioavailability (5.1 fold), and antimicrobial capacity against P. aeruginosa, E. coli, B. subtilis, and S. aureus compared to pure CEF. Our data demonstrate that bilosome is a powerful nanocarrier for oral delivery of cefepime, boosting its biological impacts and pharmacokinetic profile.},
}

@article {pmid39586337,
year = {2024},
author = {Patra, S and Saha, S and Singh, R and Tomar, N and Gulati, P},
title = {Biofilm Battleground: Unveiling the hidden challenges, current approaches and future perspectives in combating biofilm associated bacterial infections.},
journal = {Microbial pathogenesis},
volume = {},
number = {},
pages = {107155},
doi = {10.1016/j.micpath.2024.107155},
pmid = {39586337},
issn = {1096-1208},
abstract = {A biofilm is a complex aggregation of microorganisms, either of the same or different species, that adhere to a surface and are encased in an extracellular polymeric substances (EPS) matrix. Quorum sensing (QS) and biofilm formation are closely linked, as QS genes regulate the development, maturation, and breakdown of biofilms. Inhibiting QS can be utilized as an effective approach to combat the impacts of biofilm infection. The impact of biofilms includes chronic infections, industrial biofouling, infrastructure corrosion, and environmental contamination as well. Therefore, a deep understanding of biofilms is crucial for enhancing public health, advancing industrial processes, safeguarding the environment, and deepening our knowledge of microbial life as well. This review aims to offer a comprehensive examination of challenges posed by bacterial biofilms, contemporary approaches and strategies for effectively eliminating biofilms, including the inhibition of quorum sensing pathways, while also focusing on emerging technologies and techniques for biofilm treatment. In addition, future research is projected to target the challenges associated with the bacterial biofilms, striving to develop new approaches and improve existing strategies for their effective control and eradication.},
}

@article {pmid39586149,
year = {2024},
author = {Hajiaghaalizadeh, M and Sheikharabi, M and Jazi, MS and Alhashem, R and Hosseini, SS},
title = {Anti-biofilm activity of carvacrol-thymoquinone nanocarriers on vulvovaginal candidiasis isolates.},
journal = {Diagnostic microbiology and infectious disease},
volume = {111},
number = {2},
pages = {116606},
doi = {10.1016/j.diagmicrobio.2024.116606},
pmid = {39586149},
issn = {1879-0070},
abstract = {Given the recurrent nature of vulvovaginal candidiasis (VVC), the restricted availability of effective antifungal agents, and the recent rise in drug resistance, this study sought to assess the antifungal efficacy of carvacrol-thymoquinone delivered via a nanocarrier on Candida isolates obtained from patients with VVC. Isolates were identified using phenotypic and genotypic methods. Nanocarriers were synthesized using the thin-film hydration method. The antifungal activity of carvacrol-thymoquinone was evaluated using the broth microdilution method (CLSIM27-A3). The impact of nanocarriers on the biofilm formation capabilities of Candida isolates was assessed using the MTT assay. Data were analyzed using the Mann-Whitney U test. The nanocarrier exhibited a spherical morphology with a diameter measuring 50 nm. The nano-formulated drug combination could inhibit biofilm formation in C. albicans at half the minimum inhibitory concentration and in C. glabrata at the minimum inhibitory concentration. Our results suggest that the carvacrol-thymoquinone nanocarrier can be studied further in vivo for potential use in the treatment of recurrent VVC.},
}

@article {pmid39585926,
year = {2024},
author = {Prentice, JA and Kasivisweswaran, S and van de Weerd, R and Bridges, AA},
title = {Biofilm dispersal patterns revealed using far-red fluorogenic probes.},
journal = {PLoS biology},
volume = {22},
number = {11},
pages = {e3002928},
doi = {10.1371/journal.pbio.3002928},
pmid = {39585926},
issn = {1545-7885},
abstract = {Bacteria frequently colonize niches by forming multicellular communities called biofilms. To explore new territories, cells exit biofilms through an active process called dispersal. Biofilm dispersal is essential for bacteria to spread between infection sites, yet how the process is executed at the single-cell level remains mysterious due to the limitations of traditional fluorescent proteins, which lose functionality in large, oxygen-deprived biofilms. To overcome this challenge, we developed a cell-labeling strategy utilizing fluorogen-activating proteins (FAPs) and cognate far-red dyes, which remain functional throughout biofilm development, enabling long-term imaging. Using this approach, we characterize dispersal at unprecedented resolution for the global pathogen Vibrio cholerae. We reveal that dispersal initiates at the biofilm periphery and approximately 25% of cells never disperse. We define novel micro-scale patterns that occur during dispersal, including biofilm compression during cell departure and regional heterogeneity in cell motions. These patterns are attenuated in mutants that reduce overall dispersal or that increase dispersal at the cost of homogenizing local mechanical properties. Collectively, our findings provide fundamental insights into the mechanisms of biofilm dispersal, advancing our understanding of how pathogens disseminate. Moreover, we demonstrate the broad applicability of FAPs as a powerful tool for high-resolution studies of microbial dynamics in complex environments.},
}

@article {pmid39584338,
year = {2024},
author = {Yang, C and Ran, L and Yang, Z and Hu, H and Wei, W and Yang, H and Zhu, M and Yu, Y and Fu, L and Chen, H},
title = {[Screening of active components in Chinese medicine with effects on Escherichia coli biofilm based on molecular docking].},
journal = {Sheng wu gong cheng xue bao = Chinese journal of biotechnology},
volume = {40},
number = {11},
pages = {4120-4137},
doi = {10.13345/j.cjb.240113},
pmid = {39584338},
issn = {1872-2075},
mesh = {*Biofilms/drug effects ; *Escherichia coli/drug effects/genetics/metabolism ; *Molecular Docking Simulation ; *Drugs, Chinese Herbal/pharmacology/chemistry ; Tannins/pharmacology/chemistry ; Cinnamates/pharmacology/chemistry/metabolism ; Benzofurans/pharmacology/chemistry ; Depsides/pharmacology/chemistry/metabolism ; Rosmarinic Acid ; Anti-Bacterial Agents/pharmacology/chemistry ; Escherichia coli Proteins/metabolism/genetics ; Medicine, Chinese Traditional ; },
abstract = {By targeting the key gene csgD involved in the biofilm formation of Escherichia coli, we employed molecular docking and molecular dynamics simulation to screen the active components of Chinese medicine with inhibitory effects on the biofilm formation from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). After the anti-biofilm properties of the active components were validated in vitro, data-independent acquisition (DIA) proteomics was employed to further identify the differential proteins involved in interfering with the biofilm formation of Escherichia coli. The mechanisms of inhibition were explored with consideration to the phenotype. Through virtual screening, we identified four candidate active components, including tannic acid, narirutin, salvianolic acid B, and rosmarinic acid. Among them, tannic acid demonstrated significant inhibitory effect on the biofilm formation of E. coli. The analysis of differential proteins, combined with relevant phenotype validation, suggested that tannic acid primarily affected E. coli by intervening in pilus assembly, succinic acid metabolism, and the quorum sensing system. This study provided a lead compound for the development of new drugs against biofilm-associated infections in the future.},
}

*Biofilms/drug effects
*Escherichia coli/drug effects/genetics/metabolism
*Molecular Docking Simulation
*Drugs, Chinese Herbal/pharmacology/chemistry
Tannins/pharmacology/chemistry
Cinnamates/pharmacology/chemistry/metabolism
Benzofurans/pharmacology/chemistry
Depsides/pharmacology/chemistry/metabolism
Rosmarinic Acid
Anti-Bacterial Agents/pharmacology/chemistry
Escherichia coli Proteins/metabolism/genetics
Medicine, Chinese Traditional

@article {pmid39583991,
year = {2024},
author = {Gomez-Lopez, A and Fernandez-Fernandez, C},
title = {Molecular characterization of gliotoxin synthesis in a biofilm model of Aspergillus fumigatus.},
journal = {Biofilm},
volume = {8},
number = {},
pages = {100238},
pmid = {39583991},
issn = {2590-2075},
abstract = {Mycelial growth as biofilm structures and the activation of secondary metabolism leading to the release of low-molecular-weight molecules (known as secondary metabolites), are among the previously described strategies used by the filamentous fungi Aspergillus fumigatus to adapt and survive. Our study unveils that A. fumigatus strains can activate mechanisms linked to the production of gliotoxin, a crucial metabolite for Aspergillus, in the established in vitro biofilm model. Gliotoxin production exhibits strain- and time-dependent patterns and is associated -in a coordinated manner-with the expression levels of several genes involved in its regulation and synthesis. The transcriptional study of some of these genes by qPCR shows temporal inter-strain differences, which correlate with those obtained when evaluating the amounts of metabolites produced. Given that A. fumigatus forms biofilm structures within the site of infection, understanding the regulation of gliotoxin biosynthesis may have a role in the evolution of Aspergillus infection and guide diagnostic and treatment strategies.},
}

@article {pmid39582781,
year = {2024},
author = {Wen, T and Zhao, Y and Fu, Y and Chen, Y and Li, X and Shi, C and Xian, D and Zhao, W and Yang, D and Lu, C and Wu, C and Pan, X and Quan, G},
title = {"On-demand" nanosystem-integrated microneedles for amplified triple therapy against recalcitrant bacteria and biofilm growth.},
journal = {Materials today. Bio},
volume = {29},
number = {},
pages = {101327},
pmid = {39582781},
issn = {2590-0064},
abstract = {Phototherapy has emerged to eradicate recalcitrant bacteria without causing drug resistance, but it is often accompanied by considerable limitations owing to a high tolerance of recalcitrant bacteria to heat and oxidative damage, leading to low efficiency of monotherapy and unwanted side effects. Assuming that employing antimicrobial peptides (AMPs) to disrupt bacterial membranes could reduce bacterial tolerance, a multifunctional "on-demand" nanosystem based on zeolitic imidazolate framework-8 (ZIF-8) with metal ions for intrinsic antibacterial activity was constructed to potently kill methicillin-resistant Staphylococcus aureus (MRSA). Then, microneedles (MNs) were used to transdermally deliver the ZIF-8-based nanosystem for localized skin infection. After MNs insertion, the nanoplatform could specifically deliver the loaded therapeutic components to bacterial infection sites through employing hyaluronic acid (HA) as a capping agent, thus realizing the "on-demand" payload release triggered by excess hyaluronidase secreted by MRSA. The prepared nanosystem and MNs were confirmed to exert an amplified triple therapy originating from membranolytic effect, phototherapy, and ion therapy, thus displaying a powerful bactericidal and MRSA biofilm destruction ability. This intelligent antimicrobial strategy may bring a dawn of hope for eradicating multidrug-resistant bacteria and biofilms.},
}

@article {pmid39581889,
year = {2024},
author = {Zaffar, R and Nazir, R and Hameed, J and Rather, MA},
title = {Biofilm and Extracellular Polymeric Substance (EPS) synergy: Revealing Staphylococcus's role in nitrate bioremediation.},
journal = {World journal of microbiology & biotechnology},
volume = {40},
number = {12},
pages = {391},
pmid = {39581889},
issn = {1573-0972},
support = {SR/WOS-A/LS-232/2018//Department of Science and Technology, Ministry of Science and Technology, India/ ; },
mesh = {*Biofilms/growth & development ; *Biodegradation, Environmental ; *Staphylococcus/metabolism/isolation & purification/growth & development/physiology ; *Extracellular Polymeric Substance Matrix/metabolism ; *Nitrates/metabolism ; India ; Lakes/microbiology ; Denitrification ; },
abstract = {Staphylococcus species, traditionally associated with pathogenicity, are gaining attention for their role in environmental bioremediation, particularly nitrate reduction, which is crucial for mitigating eutrophication. In this study, denitrifying, biofilm-forming Staphylococcus strains were isolated from Dal Lake, India. Biofilm formation was quantified using a microtiter plate assay, and extracellular polymeric substances (EPS) were measured by dry weight. Statistical analysis revealed a strong positive correlation between EPS production and nitrate removal efficiency (r = 0.96, p < 0.001), with EPS accounting for 92% of the variance in nitrate reduction (R[2] = 0.92). Among the isolates, Staphylococcus epidermidis exhibited the highest nitrate reduction at 87% (SD = 2.3%), followed by S. succinus at 83% (SD = 2.1%), S. equorum at 77% (SD = 2.5%), and Staphylococcus sp. at 70% (SD = 2.8%). The consistency of these findings was confirmed by boxplot analysis, and the regression model's robustness was validated by residual plots showing minimal systematic error. This research work provides the first evidence of the nitrate-reducing capabilities of these Staphylococcus species, underscoring their potential in sustainable bioremediation strategies for aquatic environments. The significant correlation between EPS production and nitrate reduction highlights the critical role of biofilms in enhancing microbial remediation processes. The study not only advances the understanding of Staphylococcus in non-pathogenic roles but also suggests that these strains could be pivotal in bioremediation technologies, potentially influencing future environmental management practices.},
}

*Biofilms/growth & development
*Biodegradation, Environmental
*Staphylococcus/metabolism/isolation & purification/growth & development/physiology
*Extracellular Polymeric Substance Matrix/metabolism
*Nitrates/metabolism
India
Lakes/microbiology
Denitrification

@article {pmid39581435,
year = {2024},
author = {Ono, K and Hayashi, JI and Suzuki, Y and Yamashita, M and Nishikawa, K and Higuchi, N and Goto, R and Ohno, T and Nishida, E and Yamamoto, G and Kikuchi, T and Hasegawa, Y and Mitani, A},
title = {Photodynamic disruption of a polymicrobial biofilm of two periodontal species using indocyanine green-loaded nanospheres.},
journal = {Photodiagnosis and photodynamic therapy},
volume = {},
number = {},
pages = {104421},
doi = {10.1016/j.pdpdt.2024.104421},
pmid = {39581435},
issn = {1873-1597},
abstract = {OBJECTIVE: Antimicrobial photodynamic therapy (aPDT) is considered a potential treatment for biofilm infections, which have become an increasing health issue because of the rise in antimicrobial resistance. This study aimed to evaluate the bactericidal effect of aPDT using indocyanine green-loaded nanospheres with chitosan coating (ICG-Nano/c) against polymicrobial periodontal biofilms.

METHODS: Composite biofilms of Porphyromonas gingivalis and Streptococcus gordonii were constructed in 96-well plates, and aPDT with ICG-Nano/c and an 810 nm diode laser was performed either by direct irradiation or transmitting irradiation through a 3-mm-thick gingival model. The efficacy of ICG-Nano/c-based aPDT was compared with antibiotics (minocycline and amoxicillin). Additionally, attenuated aPDT under sublethal conditions was used to investigate gene expression related to the antioxidant response (oxyR and sod of P. gingivalis) and biofilm formation via quorum sensing (luxS of both species) with real-time polymerase chain reaction.

RESULTS: ICG-Nano/c-based aPDT significantly reduced the bacterial load in the biofilm, achieving at least a 2 log10 reduction in colony-forming units within 5 minutes for both irradiation methods. After 6 hours of treatment, the bactericidal effects of aPDT and antibiotics were similar, but after 32 hours, antibiotics were more effective, particularly against P. gingivalis. Attenuated aPDT showed a slight increase in sod expression in P. gingivalis, while luxS expression decreased in both bacteria.

CONCLUSION: The ICG-Nano/c-based aPDT system exerted a certain degree of bactericidal activity against a composite biofilm of periodontal bacteria. Therefore, it has potential as an alternative option or adjunctive therapy to conventional antibiotics in periodontal treatment.},
}

@article {pmid39580490,
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 = {Nature communications},
volume = {15},
number = {1},
pages = {10184},
pmid = {39580490},
issn = {2041-1723},
support = {3P01AI083211//U.S. Department of Health & Human Services | NIH | National Institute of Allergy and Infectious Diseases (NIAID)/ ; F32NS126302//U.S. Department of Health & Human Services | NIH | National Institute of Neurological Disorders and Stroke (NINDS)/ ; },
mesh = {*Biofilms/growth & development ; *Staphylococcus aureus/genetics/physiology/immunology ; *Single-Cell Analysis/methods ; *Sequence Analysis, RNA/methods ; Gene Expression Regulation, Bacterial ; Gene Regulatory Networks ; Animals ; Virulence/genetics ; Humans ; },
abstract = {Biofilm formation is an important mechanism of survival and persistence for many bacterial pathogens. These multicellular communities contain subpopulations of cells that display metabolic and transcriptional diversity along with recalcitrance to antibiotics and host immune defenses. Here, we present 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. BaSSSh-seq captures extensive transcriptional heterogeneity during biofilm compared to planktonic growth. We quantify and visualize transcriptional regulatory networks across heterogeneous biofilm subpopulations and identify gene sets that are associated with a trajectory from planktonic to biofilm growth. BaSSSh-seq also detects alterations in biofilm metabolism, stress response, and virulence induced by distinct immune cell populations. This work facilitates the exploration of biofilm dynamics at single-cell resolution, unlocking the potential for identifying biofilm adaptations to environmental signals and immune pressure.},
}

*Biofilms/growth & development
*Staphylococcus aureus/genetics/physiology/immunology
*Single-Cell Analysis/methods
*Sequence Analysis, RNA/methods
Gene Expression Regulation, Bacterial
Gene Regulatory Networks
Animals
Virulence/genetics
Humans

@article {pmid39579939,
year = {2024},
author = {Semeshchenko, D and Veiga, MF and Visus, M and Farinati, A and Huespe, I and , and Buttaro, MA and Slullitel, PA and , },
title = {Povidone-iodine and Silver-nitrate are Equally Effective in Eradicating Staphylococcal Biofilm Grown on a Titanium Surface: An in vitro Analysis.},
journal = {The Journal of hospital infection},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.jhin.2024.11.012},
pmid = {39579939},
issn = {1532-2939},
abstract = {BACKGROUND: There is no consensus on the irrigation solution and concentration that should be used when performing a debridement, antibiotics, and implant retention (DAIR)-surgery.

AIM: To determine the minimum-biofilm-eradication-concentration of five antibacterial solutions and compare their efficacy in eradicating Staphylococcal biofilm embedded on a titanium surface.

METHODS: Methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) ATCC standard strains were grown over porous Ti-6Al-4V acetabular screw-caps. Antibacterial solutions were povidone iodine, rifampicin, silver nitrate, copper sulphate, chlorhexidine. Minimum biofilm eradication concentration (MBEC) values were calculated for MSSA and MRSA. After 24 hours, screw-caps were exposed 3 minutes to each solution. Bacterial separation from each specimen was performed with vortex agitation and footprint on agar plate in triplicate. Colony forming units (CFU) were counted pre- and post-agitation, and the delta of CFU/ml was calculated for each solution. A three-fold log reduction in CFU was considered a measure of solution efficacy. Comparison between groups was made with Fisher's test.

FINDINGS: MBEC values for MSSA and MRSA, respectively, were as follows: 8000 ug/mL and 16000 ug/ml for povidone iodine; 64 ug/mL and 128 ug/mL for rifampicin; 10000 ug/mL and 5120 ug/mL for silver nitrate; 900 ug/mL and 900 ug/mL for copper sulphate; 16 ug/mL and 32 ug/mL for chlorhexidine. Rifampicin, copper sulphate and chlorhexidine were ineffective against MSSA and MRSA biofilm compared to povidone iodine (p<0.01) and silver nitrate (p=0.015) that had a delta CFU reduction >8 log. Povidone iodine and silver nitrate showed negative footprints without visible MSSA (p=0.005) and MRSA (p=0.014).

CONCLUSIONS: Povidone iodine and silver nitrate were the only irrigating solutions capable of eradicating at least 99.9% of 24-hour biofilm.},
}

@article {pmid39579902,
year = {2024},
author = {Díaz-Muñiz, CA and Nieto-Delgado, C and IIhan, ZE and Rittmann, BE and Ontiveros-Valencia, A},
title = {Lead removal by its precipitation with biogenic sulfide in a membrane biofilm reactor.},
journal = {The Science of the total environment},
volume = {},
number = {},
pages = {177578},
doi = {10.1016/j.scitotenv.2024.177578},
pmid = {39579902},
issn = {1879-1026},
abstract = {We evaluated the feasibility of using hydrogen (H2)-based membrane biofilm reactors (MBfRs) to promote the growth of hydrogenotrophic sulfate-reducing bacteria (SRB) to remove lead (Pb) through its precipitation as lead sulfide (PbS) via biogenic sulfide (HS[-]) production. Two MBfRs (R1 and R2) were set-up to treat synthetic water rich in sulfate (SO4[2-]) (585 mg/L) and Pb (50, 100, or 250 mg/L). R1 had one influent that had the Pb and synthetic media mixed together; R2 received the Pb solution and synthetic medium through separate influent lines. Oxygen (O2) and nitrate (NO3[-]) were secondary electron acceptors in R1 and R2, respectively. R1 and R2 produced enough HS[-] (> 73 mg/L) to precipitate Pb, and Pb removal reached >97 %. Chemical equilibrium calculations identified which solids were possible in each stage of operation. Precipitation of Pb with phosphate (PO4[3-]) occurred in the feed solution in R1, but phosphate precipitation was avoided in the R2 influent. The predominant Pb precipitate inside R2 was PbS, which was confirmed by SEM-EDX analysis. The microbial communities of R1 and R2 were dominated by two SRB - Desulfomicrobium and Fusibacter - along with sulfur oxidizer Thiovirga and denitrifier Thauera. Although the presence of electron acceptors other than SO4[2-] enabled other respiratory metabolisms, they did not prevent SO4[2-] reduction to HS[-] or the precipitation of PbS.},
}

@article {pmid39579496,
year = {2024},
author = {He, X and Sheng, X and Yao, X and Wang, Y and Zhang, L and Wang, H and Yuan, L},
title = {The anti-biofilm effect of α-amylase/glycopolymer-decorated gold nanorods.},
journal = {Colloids and surfaces. B, Biointerfaces},
volume = {246},
number = {},
pages = {114393},
doi = {10.1016/j.colsurfb.2024.114393},
pmid = {39579496},
issn = {1873-4367},
abstract = {The continuous evolution of bacteria and the formation of biofilm have exacerbated resistance issues, highlighting the urgent need for new antibacterial materials. In this study, L-fucose was polymerized to synthesize thiolated poly(2-(L-fucose) ethyl methacrylate) (PFEMA-SH), which was subsequently co-modified with α-amylase onto gold nanorods (GNR) to prepare the antibacterial nanoparticle composite, GNR-Amy-PFEMA (G-A-P). These nanomaterials exhibit both photothermal and enzymatic properties, enabling G-A-P to effectively sterilize and disperse biofilm. Under near-infrared light irradiation, the temperature of G-A-P composite increases significantly, leading to bacterial cell damage and biofilm disruption. The G-A-P composite demonstrated nearly 100 % eradication of planktonic bacteria after 5 min of irradiation and achieved a 70.9 % reduction in mature biofilm biomass, with a 3.37-log decrease in the number of bacteria within the biofilm. These composites display strong antimicrobial activity and hold great potential for the removal of Pseudomonas aeruginosa biofilm. Furthermore, the ability of G-A-P to reduce biofilm formation without the use of traditional antibiotics suggests that it may offer an antibiotic-free alternative for managing biofilm-related infections.},
}

@article {pmid39579303,
year = {2024},
author = {Chen, YY and Liu, ZS and Chen, BY and Tam, HM and Shia, WY and Yu, HH and Chen, PW},
title = {Effects of Heat-Killed Probiotic Strains on Biofilm Formation, Transcription of Virulence-Associated Genes, and Prevention of UTIs in Mice.},
journal = {Probiotics and antimicrobial proteins},
volume = {},
number = {},
pages = {},
pmid = {39579303},
issn = {1867-1314},
support = {YSHV 112-07//Taipei Veterans General Hospital/ ; YSHV 112-07//Taipei Veterans General Hospital/ ; grants 112-2313-B-005-037//National Science and Technology Council/ ; },
abstract = {Urinary tract infections (UTIs) pose a substantial healthcare challenge, exacerbated by the biofilm-forming abilities and antibiotic resistance of uropathogens. This study investigated the inhibition of biofilm formation (anti-biofilm) and dispersion of pre-established biofilm properties of 18 heat-killed probiotics and their supernatants against four antibiotic-resistant uropathogens: UPEC, Klebsiella pneumoniae (KP), Methicillin-resistant Escherichia coli (MREC), and Methicillin-resistant Staphylococcus pseudintermedius (MRSP). Supernatants from 14 probiotic strains significantly (P < 0.001) inhibited UPEC biofilm formation, reducing it by 20-80%, and also showed promise in removing existing biofilms by 10-60% (P < 0.001). Eight strains significantly (P < 0.05 to < 0.001) inhibited MREC biofilm formation, with four strains achieving 50-80% dispersion. Seventeen strains of heat-killed probiotics directly inhibited UPEC biofilm formation by 10-60% (P < 0.05 to < 0.001), but were less effective against MREC and MRSP (10-50% reduction; P < 0.05 to < 0.001) and had limited impact on KP (10% reduction; P < 0.05 to < 0.001). Notably, heat-killed probiotic like LGA, LGC, LGD, TP-8, and TP-4 showed the most significant inhibitory and dispersion of biofilm activity. RT-qPCR analysis further revealed these inactivated probiotics downregulated genes associated with pili and biofilm formation (fimA, csgA) and upregulated genes linked to quorum sensing (luxS, qseBC, sdiA). Therefore, these findings suggest that paraprobiotic treatment could inhibit the formation of pili and biofilms and promote biofilm dispersion. In an animal model, mice given paraprobiotic formulations I (16 strains) and II (a specific mixture) for 2 weeks showed reduced urinary bacterial load (P < 0.05). Paraprobiotic I notably reduced morbidity from bacteriuria (> 10[5] CFU/ml) by 5 to 30% within the first 5 days post-infection compared to placebo. These findings highlight the potential of specific heat-killed probiotics in combating biofilms and preventing UTIs.},
}

@article {pmid39578969,
year = {2024},
author = {Srivastava, N and Deka, S and Kumar, L},
title = {A dual-action strategy of propenyl guaethol: pilY-mediated biofilm inhibition and augmenting aminoglycoside antibiofilm activity against Pseudomonas aeruginosa through in vitro and in silico studies.},
journal = {Journal of biomolecular structure & dynamics},
volume = {},
number = {},
pages = {1-16},
doi = {10.1080/07391102.2024.2429021},
pmid = {39578969},
issn = {1538-0254},
abstract = {Flavoring compounds are natural or synthetic substances that enhance the food flavor. Research studies have demonstrated that flavoring compounds may have biological activities. In food industry, P. aeruginosa dominates spoilage and contamination of food products. Human exposure to P. aeruginosa may lead to serious infections. P. aeruginosa forms complex biofilms with extracellular slime matrix, providing protection against antimicrobial agents. The present study investigates the role of a flavouring food additive, propenyl guaethol (PG) against Pseudomonas aeruginosa biofilms. Our results demonstrate a significant impact of PG on biofilm forming ability, bacterial attachment, and motility phenotypes. The polystyrene tube assay demonstrates notable inhibition of biofilm formation by P. aeruginosa at 50 and 25 µg/ml (p < 0.01). PG showed marked inhibition of biofilms in combination with gentamicin, kanamycin, and streptomycin. Additionally, PG inhibits twitching, swarming, and swimming motility of P. aeruginosa (p < 0.01). Scanning electron microscopy, fluorescent microscopy, and light microscopy showed thinner biofilms with low exopolysaccharide matrix (EPS) in the presence of PG. Moreover, the role of PG was also evaluated using molecular docking and molecular dynamics simulation to understand the interaction of PG with bacterial type-IV pili subunit, PilY1. PG showed favourable interactions and stable complex formation with type-IV pili subunit (PilY1). The present study highlights the antibiofilm properties of PG, suggesting its potential as a biofilm control flavoring compound.},
}

@article {pmid39577523,
year = {2024},
author = {Salim, A and Sathishkumar, P},
title = {Therapeutic efficacy of chitosan-based hybrid nanomaterials to treat microbial biofilm and their infections - A review.},
journal = {International journal of biological macromolecules},
volume = {},
number = {},
pages = {137850},
doi = {10.1016/j.ijbiomac.2024.137850},
pmid = {39577523},
issn = {1879-0003},
abstract = {Antimicrobial resistance, the biggest issue facing the global healthcare sector, quickly emerged and spread due to the frequent use of antibiotics in regular treatments. The investigation of polymer-based nanomaterials as possible antibiofilm treatment agents is prompted by the growing ineffectiveness of conventional therapeutic techniques against these resistant bacteria species. So far, several articles have been published on microbial biofilm eradication using various polymer-based nanomaterials due to their therapeutic efficacy and biocompatibility nature. Despite their potential, a comprehensive review of the chitosan-based hybrid nanomaterials to treat microbial biofilm and infections is lacking. This review provides a comprehensive investigation of the current state of therapeutic efficacy, various nanoformulations, advantages, limitations, and regulations of chitosan-based hybrid nanomaterials for biofilm treatment. Special attention is given to the application of chitosan-based nanomaterials in wound care, urinary tract infections (UTIs), and dental biofilms are discussed, highlighting their role in managing biofilm-associated complications. Researchers will be better able to comprehend and develop unique, marketable chitosan-based nanomaterials with increased activity to treat biofilm infections in near future with the aid of this review.},
}

@article {pmid39574716,
year = {2024},
author = {Kivimaki, SE and Dempsey, S and Camper, C and Tani, JM and Hicklin, IK and Blaby-Haas, CE and Brown, AM and Melville, SB},
title = {Type IV pili-associated secretion of a biofilm matrix protein from Clostridium perfringens that forms intermolecular isopeptide bonds.},
journal = {bioRxiv : the preprint server for biology},
volume = {},
number = {},
pages = {},
doi = {10.1101/2024.11.04.621531},
pmid = {39574716},
issn = {2692-8205},
abstract = {UNLABELLED: Clostridium perfringens is a Gram-positive anaerobic spore-forming bacterial pathogen of humans and animals. C. perfringens also produces type IV pili (T4P) and has two complete sets of T4P-associated genes, one of which has been shown to produce surface pili needed for cell adherence. One hypothesis about the role of the other set of T4P genes is that they could comprise a system analogous to the type II secretion systems (TTSS) found in Gram-negative bacteria, which is used to export folded proteins from the periplasm through the outer membrane to the extracellular environment. Gram-positive bacteria have a similar secretion barrier in the thick peptidoglycan (PG) layer, which blocks secretion of folded proteins >25 kD. To determine if the T4P-associated genes comprise a Gram-positive TTSS, the secretome of mutants lacking type IV pilins were examined and a single protein, a von Willebrand A domain containing protein BsaC (CPE0517) was identified as being dependent on PilA3 for secretion. BsaC is in an operon with a signal peptidase and two putative biofilm matrix proteins with homology to Bacillus subtilis TasA. One of these proteins, BsaA, was shown by another group to produce high mol wt oligomers. We analyzed BsaA monomer interactions with de novo modeling, which projected that the monomers formed isopeptide bonds as part of a donor strand exchange process. Mutations in residues predicted to form the isopeptide bonds led to loss of oligomerization, supporting the predicted bond formation process. Phylogenetic analysis showed the BsaA family of proteins are widespread among bacteria and archaea but only a subset are predicted to form isopeptide bonds.

IMPORTANCE: For bacteria to secrete folded proteins to the environment, they have to overcome the physical barriers of an outer membrane in Gram-negative bacteria and the thick peptidoglycan layer in Gram-positive bacteria. One mechanism to do this is the use of a Type II secretion system in Gram-negative bacteria, which has a similar structure as type IV pili and is modeled to act as a piston that pumps folded proteins through the outer membrane to the environment. Clostridium perfringens , like all or most all of the clostridia, has type IV pili and, in fact, has two sets of pilus-associated genes. Here we present evidence that C. perfringens uses one set of pilus genes to secrete a biofilm associated protein and may be responsible for secreting the main biofilm protein BsaA. We show that BsaA monomers are, unlike most other biofilm matrix proteins, linked by intermolecular isopeptide bonds, enhancing the physical strength of BsaA fibers.},
}

@article {pmid39574578,
year = {2024},
author = {Keim, K and Bhattacharya, M and Crosby, HA and Jenul, C and Mills, K and Schurr, M and Horswill, A},
title = {Polymicrobial interactions between Staphylococcus aureus and Pseudomonas aeruginosa promote biofilm formation and persistence in chronic wound infections.},
journal = {bioRxiv : the preprint server for biology},
volume = {},
number = {},
pages = {},
doi = {10.1101/2024.11.04.621402},
pmid = {39574578},
issn = {2692-8205},
abstract = {Chronic, non-healing wounds are a leading cause of prolonged patient morbidity and mortality due to biofilm-associated, polymicrobial infections. Staphylococcus aureus and Pseudomonas aeruginosa are the most frequently co-isolated pathogens from chronic wound infections. Competitive interactions between these pathogens contribute to enhanced virulence, persistence, and antimicrobial tolerance. P. aeruginosa utilizes the extracellular proteases LasB, LasA, and AprA to degrade S. aureus surface structures, disrupt cellular physiology, and induce cell lysis, gaining a competitive advantage during co-infection. S. aureus evades P. aeruginosa by employing aggregation mechanisms to form biofilms. The cell wall protein SasG is implicated in S. aureus biofilm formation by facilitating intercellular aggregation upon cleavage by an extracellular protease. We have previously shown that proteolysis by a host protease can induce aggregation. In this study, we report that P. aeruginosa proteases LasA, LasB, and AprA cleave SasG to induce S. aureus aggregation. We demonstrate that SasG contributes to S. aureus biofilm formation in response to interactions with P. aeruginosa proteases by quantifying aggregation, SasG degradation, and proteolytic kinetics. Additionally, we assess the role of SasG in influencing S. aureus biofilm architecture during co-infection in vivo, chronic wound co-infections. This work provides further knowledge of some of the principal interactions that contribute to S. aureus persistence within chronic wounds co-infected with P. aeruginosa, and their impact on healing and infection outcomes.},
}

@article {pmid39574143,
year = {2024},
author = {MacLean, J and Bartholomäus, A and Blukis, R and Liebner, S and Wagner, D},
title = {Metatranscriptomics of microbial biofilm succession on HDPE foil: uncovering plastic-degrading potential in soil communities.},
journal = {Environmental microbiome},
volume = {19},
number = {1},
pages = {95},
pmid = {39574143},
issn = {2524-6372},
support = {02WPL1449D//Bundesministerium für Bildung und Forschung/ ; I-044-16-0//Helmholtz-Gemeinschaft/ ; },
abstract = {BACKGROUND: Although plastic pollution is increasing worldwide, very little is known about the microbial processes that take place once plastic debris is incorporated into the soil matrix. In this study, we conducted the first metatranscriptome analysis of polyethylene (PE)-associated biofilm communities in highly polluted landfill soil and compared their gene expression to that of a forest soil community within a 53-day period.

RESULTS: Our findings indicate that the microbial population present in soil contaminated with plastic debris is predisposed to both inhabit and degrade plastic surfaces. Surprisingly, the microbial community from undisturbed forest soil contained a diverse array of plastic-associated genes (PETase, alkB, etc.), indicating the presence of an enzymatic machinery capable of plastic degradation. Plastic-degrading taxa were upregulated in the early stages of biofilm formation. During the maturation of the biofilm, the alkB1/alkM transcripts, which encode PE-degrading enzymes, and transporters such as fadL, livG, livF, livH, and livM were upregulated, along with transcripts associated with the fatty acid β-oxidation pathway.

CONCLUSIONS: In this study, we address the underlying patterns of gene expression during biofilm development in a PE-associated plastisphere in soil and address the pressing question of whether natural microbial communities have the potential to biodegrade petrochemical-based plastic in the soil environment.},
}

@article {pmid39572965,
year = {2024},
author = {Shrestha, S and Basnet, A and Maharjan, R and Basnet, B and Joshi, P},
title = {Biofilm-Associated Multidrug-Resistant and Methicillin-Resistant Staphylococcus aureus Infections.},
journal = {Journal of Nepal Health Research Council},
volume = {22},
number = {2},
pages = {410-418},
pmid = {39572965},
issn = {1999-6217},
mesh = {*Biofilms/drug effects ; Humans ; Cross-Sectional Studies ; Female ; Male ; Child, Preschool ; *Methicillin-Resistant Staphylococcus aureus/drug effects/isolation & purification ; Nepal/epidemiology ; Infant ; *Staphylococcal Infections/microbiology/epidemiology/drug therapy ; *Drug Resistance, Multiple, Bacterial ; Child ; *Anti-Bacterial Agents/pharmacology ; *Microbial Sensitivity Tests ; Adolescent ; Staphylococcus aureus/drug effects/isolation & purification ; Prevalence ; },
abstract = {BACKGROUND: The ability of Staphylococcus aureus to form biofilmsâ€"architectural complexes that cause chronic and recalcitrant infectionsâ€"along with its notorious variant, methicillin-resistant Staphylococcus aureus (MRSA), leads to multidrug-resistant (MDR) infections that are challenging to treat with antibiotics. This cross-sectional study investigated the prevalence of S. aureus infections in Kanti Children’s Hospital and characterized the antibiograms of MDR, MRSA, and biofilm-forming strains, along with their coexistence.

METHODS:  S. aureus strains were isolated and identified from clinical samples and tested for antibiograms following standard microbiology guidelines. MDR strains were non-susceptible to at least one agent in three antimicrobial categories, whereas MRSA strains were cefoxitin-resistant. The microtiter plate method was used to detect biofilms. Statistical analyses were performed using SPSS version 17.0.

RESULTS:  S. aureus was detected in 9.0% (11.4-6.6%, 95% Confidence Interval) of 543 samples, primarily from pus (79.6%, 39/49). Children aged 1 to <3 years most commonly contracted infections (30.6%, 15/49), and males (67.4%, 33/49) had twice as many infections as females (32.7%, 16/49). As high as 84.7% (83/98) of strains were penicillin-resistant, while 18.4% (27/147) were aminoglycoside-resistant. MDR accounted for 79.6% (39/49) of all S. aureus infections, while MRSA and biofilm-formers accounted for 67.6% (33/49) and 24.5% (12/49), respectively. Fluoroquinolone resistance in non-MDR-MRSA-biofilm-formers, MDR-MRSA, MDR-biofilm-formers, and MRSA-biofilm-formers was 31.3%, 46.8%, 58.3%, and 60.0%, respectively, while aminoglycoside resistance was 0%, 32.3%, 50.0%, and 45.0%, and penicillin resistance was 87.5%, 85.5%, 100.0%, and 100.0%.

CONCLUSIONS:  MDR-isolates and MRSA caused nearly four-fifths of S. aureus infections. Compared to MDR and MRSA strains, biofilm-formers triggered higher levels of antimicrobial resistance.},
}

*Biofilms/drug effects
Humans
Cross-Sectional Studies
Female
Male
Child, Preschool
*Methicillin-Resistant Staphylococcus aureus/drug effects/isolation & purification
Nepal/epidemiology
Infant
*Staphylococcal Infections/microbiology/epidemiology/drug therapy
*Drug Resistance, Multiple, Bacterial
Child
*Anti-Bacterial Agents/pharmacology
*Microbial Sensitivity Tests
Adolescent
Staphylococcus aureus/drug effects/isolation & purification
Prevalence

@article {pmid39572562,
year = {2024},
author = {Guo, J and Van De Ven, WT and Skirycz, A and Thirumalaikumar, VP and Zeng, L and Zhang, Q and Balcke, GU and Tissier, A and Dehesh, K},
title = {An evolutionarily conserved metabolite inhibits biofilm formation in Escherichia coli K-12.},
journal = {Nature communications},
volume = {15},
number = {1},
pages = {10079},
pmid = {39572562},
issn = {2041-1723},
support = {R01GM107311-8//U.S. Department of Health & Human Services | NIH | National Institute of General Medical Sciences (NIGMS)/ ; },
mesh = {*Biofilms/drug effects/growth & development ; *Escherichia coli K12/genetics/metabolism/drug effects/physiology ; *Escherichia coli Proteins/metabolism/genetics ; *Gene Expression Regulation, Bacterial ; *Fimbriae, Bacterial/metabolism/genetics ; Oxidative Stress ; Promoter Regions, Genetic ; Erythritol/analogs & derivatives/metabolism/pharmacology ; },
abstract = {Methylerythritol cyclodiphosphate (MEcPP) is an intermediate in the biosynthesis of isoprenoids in plant plastids and in bacteria, and acts as a stress signal in plants. Here, we show that MEcPP regulates biofilm formation in Escherichia coli K-12 MG1655. Increased MEcPP levels, triggered by genetic manipulation or oxidative stress, inhibit biofilm development and production of fimbriae. Deletion of fimE, encoding a protein known to downregulate production of adhesive fimbriae, restores biofilm formation in cells with elevated MEcPP levels. Limited proteolysis-coupled mass spectrometry (LiP-MS) reveals that MEcPP interacts with the global regulatory protein H-NS, which is known to repress transcription of fimE. MEcPP prevents the binding of H-NS to the fimE promoter. Therefore, our results indicate that MEcPP can regulate biofilm formation by modulating H-NS activity and thus reducing fimbriae production. Further research is needed to test whether MEcPP plays similar regulatory roles in other bacteria.},
}

*Biofilms/drug effects/growth & development
*Escherichia coli K12/genetics/metabolism/drug effects/physiology
*Escherichia coli Proteins/metabolism/genetics
*Gene Expression Regulation, Bacterial
*Fimbriae, Bacterial/metabolism/genetics
Oxidative Stress
Promoter Regions, Genetic
Erythritol/analogs & derivatives/metabolism/pharmacology

@article {pmid39572453,
year = {2024},
author = {Méndez, A and Sanmartín, P and Balboa, S and Trueba-Santiso, A},
title = {Environmental Proteomics Elucidates Phototrophic Biofilm Responses to Ornamental Lighting on Stone-built Heritage.},
journal = {Microbial ecology},
volume = {87},
number = {1},
pages = {147},
pmid = {39572453},
issn = {1432-184X},
support = {04_IN606D_2021_2598528//Programa de Doutoramento Industrial - Xunta de Galicia/ ; ED431F 2022/14//FONTES project - Xunta de Galicia/ ; ED431F 2022/14//FONTES project - Xunta de Galicia/ ; ED431C 2022/09//Competitive Reference Group (GRC) grant - GEMAP/ ; ED431C 2022/09//Competitive Reference Group (GRC) grant - GEMAP/ ; RYC2020-029987-I//Ramón y Cajal contract - Spanish State Research Agency (AEI)/ ; ED431C-2021/37//Competitive Reference Group (GRC) - Biogroup/ ; ED431C-2021/37//Competitive Reference Group (GRC) - Biogroup/ ; },
mesh = {*Biofilms/radiation effects/growth & development ; *Proteomics ; Light ; Phototrophic Processes ; Cyanobacteria/metabolism/radiation effects/physiology ; Chlorophyta/radiation effects/metabolism/physiology ; Proteome ; Lighting ; },
abstract = {Recent studies are showing that some lights suitable for illuminating the urban fabric (i.e. that do not include the red, green and blue sets of primary colours) may halt biological colonisation on monuments, mainly that caused by phototrophic subaerial biofilms (SABs), which may exacerbate the biodeterioration of substrates. However, the light-triggered mechanisms that cause changes in the growth of the phototrophs remain unknown. Environmental proteomics could be used to provide information about the changes in the SAB metabolism under stress inflicted by nocturnal lighting. Here, laboratory-produced SABs, composed of Chlorophyta, Streptophyta and Cyanobacteriota, were subjected to three types of lighting used for monuments: cool white, warm white and amber + green (potentially with a biostatic effect). A control without light (i.e. darkness) was also included for comparison. The nocturnal lighting impaired the capacity of the SABs to decompose superoxide radicals and thus protect themselves from oxidative stress. Cool white and warm white light both strongly affected the proteomes of the SABs and reduced the total peptide content, with the extent of the reduction depending on the genera of the organisms involved. Analysis of the photo-damaging effect of amber + green light on the biofilm metabolism revealed a negative impact on photosystems I and II and production of photosystem antenna protein-like, as well as a triggering effect on protein metabolism (synthesis, folding and degradation). This research provides, for the first-time, a description of the proteomic changes induced by lighting on SABs colonising illuminated monuments in urban areas.},
}

*Biofilms/radiation effects/growth & development
*Proteomics
Light
Phototrophic Processes
Cyanobacteria/metabolism/radiation effects/physiology
Chlorophyta/radiation effects/metabolism/physiology
Proteome
Lighting

@article {pmid39572363,
year = {2024},
author = {Kim, HT and Çakmak, G and Jo, YH and Jee, EB and Cho, JH and Yoon, HI and Yilmaz, B},
title = {Surface properties and biofilm formation on resins for subtractively and additively manufactured fixed dental prostheses aged in artificial saliva: Effect of material type and surface finishing.},
journal = {The Journal of prosthetic dentistry},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.prosdent.2024.10.039},
pmid = {39572363},
issn = {1097-6841},
abstract = {STATEMENT OF PROBLEM: Additive manufacturing (AM) and subtractive manufacturing (SM) have been widely used for fabricating resin-based fixed dental prostheses. However, studies on the effects of material type (AM or SM resin) and surface finishing (polishing or glazing) on the surface properties and biofilm formation are lacking.

PURPOSE: The purpose of this in vitro study was to investigate the effects of material type and surface finishing on the surface roughness, wettability, protein adsorption, and microbial adhesion of the AM and SM resins marketed for fixed restorations under artificial saliva-aged conditions.

MATERIAL AND METHODS: Disk-shaped specimens (∅10×2 mm) were fabricated using 3 types of resins: AM composite resin with fillers (AMC), AM resin without fillers (AMU), and SM composite resin with fillers (SMC). Each resin group was divided into 2 subgroups based on surface finishing: polished (P) and glazed (G). Therefore, 3 polished surface groups (AMCP, AMUP, and SMCP) and 3 glazed surface groups (AMCG, AMUG, and SMCG) were prepared. Specimens were then categorized according to aging condition in artificial saliva. Surface roughness (Ra and Sa), contact angle, surface free energy (SFE), protein adsorption, and microbial adhesion were measured. The data were analyzed using a nonparametric factorial analysis of variances and post hoc tests with Bonferroni correction (α=.05).

RESULTS: When nonaged, significant interactions between material type and surface finishing were detected for Ra, contact angle, SFE, protein adsorption, and microbial adhesion (P≤.008). AMCP showed higher Ra and microbial adhesion than AMUP and SMCP, and higher contact angle and protein adsorption than SMCP (P<.001). AMCG had lower SFE than AMUG (P=.005) and higher bacterial adhesion than SMCG (P<.001). AMC had higher Sa than AMU and SMC (P≤.006). When aged, significant interactions between material type and surface finishing were detected for Ra, Sa, protein adsorption, and microbial adhesion (P≤.026). The contact angle and SFE were significantly affected only by the material type (P≤.001), as AMC exhibited higher wettability than SMC (P≤.004). AMCP had higher Ra and microbial adhesion than AMUP and SMCP (P≤.003). AMCP had higher Sa and protein adsorption than SMCP (P≤.004). AMCG showed lower Ra and higher protein adsorption than AMUG (P≤.001).

CONCLUSIONS: Both material type and surface finishing significantly affected surface properties and biofilm formation. AMCP exhibited higher surface roughness, protein adsorption, and microbial adhesion compared with SMCP. Glazing may reduce the differences in surface-biofilm interactions between AMC and SMC.},
}

@article {pmid39567638,
year = {2024},
author = {Matsumoto, Y and Nakayama, M and Shimizu, Y and Koganesawa, S and Kanai, H and Sugiyama, Y and Kurakado, S and Sugita, T},
title = {Role of Hog1-mediated stress tolerance in biofilm formation by the pathogenic fungus Trichosporon asahii.},
journal = {Scientific reports},
volume = {14},
number = {1},
pages = {28761},
pmid = {39567638},
issn = {2045-2322},
support = {JP23K06141//Japan Society for the Promotion of Science/ ; JP23fk0108679h0401//Japan Agency for Medical Research and Development/ ; },
mesh = {*Biofilms/growth & development ; *Oxidative Stress ; *Mitogen-Activated Protein Kinases/metabolism/genetics ; Animals ; *Fungal Proteins/genetics/metabolism ; Bombyx/microbiology ; Mutation ; Gene Expression Regulation, Fungal ; Stress, Physiological ; Trichosporon/genetics/physiology ; Basidiomycota ; },
abstract = {Trichosporon asahii, a dimorphic fungus, causes bloodstream infections in immunocompromised patients with neutropenia. Biofilms are formed on the surfaces of medical devices such as catheters as T. asahii transitions morphologically from yeast to hyphae in the host environment. Oxidative stress tolerance and morphological changes of T. asahii are regulated by Hog1, a mitogen-activated protein kinase. The role of Hog1 in the biofilm formation by T. asahii, however, has remained unknown. In the present study, we demonstrated that a hog1 gene-deficient T. asahii mutant formed excess biofilm under a rich medium in vitro, but did not form biofilm in an in vivo evaluation system using silkworms. The hog1 gene-deficient T. asahii mutant formed a greater amount of biofilm than the parent strain in vitro. Under an oxidative stress condition in vitro, however, lower amounts of biofilm were formed by the hog1 gene-deficient T. asahii mutant than by the parent strain. In an in vivo evaluation system using silkworms, lower amounts of biofilm were formed by the hog1 gene-deficient T. asahii mutant than by the parent strain. Our findings suggest that Hog1 regulates biofilm formation by T. asahii in response to host environmental conditions, including oxidative stress.},
}

*Biofilms/growth & development
*Oxidative Stress
*Mitogen-Activated Protein Kinases/metabolism/genetics
Animals
*Fungal Proteins/genetics/metabolism
Bombyx/microbiology
Mutation
Gene Expression Regulation, Fungal
Stress, Physiological
Trichosporon/genetics/physiology
Basidiomycota

@article {pmid39566691,
year = {2024},
author = {An, X and Chen, S and Fu, J and Yang, C and Xiao, Y and Zhou, Z},
title = {Metabolic coupling of aerobic methane oxidation and short-cut nitrification and denitrification for anaerobic effluent treatment in photo-sequencing batch biofilm reactor.},
journal = {Bioresource technology},
volume = {},
number = {},
pages = {131845},
doi = {10.1016/j.biortech.2024.131845},
pmid = {39566691},
issn = {1873-2976},
abstract = {This study explored the use of algae to supply oxygen in situ as an alternative to mechanical aeration for anaerobic effluent treatment in a photo-sequencing batch biofilm reactor (PSBBR). By establishing alternating aerobic (dissolved oxygen (DO) > 2 mg /L)/anoxic conditions (<0.5 mg-DO/L) through a 6-h off/6-h on biogas sparging cycle and continuous illumination (1500-3000 lx), the PSBBR achieved a significant ammonia removal rate of 15-25 mg N L[-1]d[-1]. This system demonstrated robust partial nitrification and nitrite reduction activities, coupled with aerobic methane oxidation. Metagenomic analysis revealed the enrichment of key microbial groups, including Leptolyngbyaceae, Methylocystis, Nitrosomonas and Hyphomicrobium. The key functional genes of methane (mmo, mdh, gfa, frm and fdh) and nitrogen (amo, hao, narGHI, and napAB) metabolisms were identified, while notably lacking nitrite oxidation genes. In conclusion, this study provides a promising post-treatment approach for anaerobic effluent through integrating biogas utilization with efficient nitrogen removal.},
}

@article {pmid39566593,
year = {2024},
author = {Cui, W and Liang, X and Xiao, W and Wang, Y and Liu, F and Chen, S and Long, J and Jin, Y and Duan, G and Yang, H},
title = {The role and mechanism of efflux pump norB in biofilm formation of Staphylococcus aureus.},
journal = {Gene},
volume = {},
number = {},
pages = {149105},
doi = {10.1016/j.gene.2024.149105},
pmid = {39566593},
issn = {1879-0038},
abstract = {Staphylococcus aureus (S. aureus) is one of the notorious bacteria responsible for community and hospital infections. It can attach to the indwelling medical devices to form biofilms, which increases resistance to antibiotics and causes frequent chronic or persistent infections. This study attempted to determine the contribution and mechanism between the efflux pump norB gene and biofilm development in S. aureus. The expression levels of norB gene were detected by quantitative real-time polymerase chain reaction (qRT-PCR). The norB gene knockout strain USA300 ΔnorB was constructed by homologous recombination technology. Crystal violet staining was utilized to detect the biofilm formation ability. Differentially expressed genes between norB knockout strains and wild-type strains were screened by RNA-Seq technology and verified by qRT-PCR. In comparison to strains with weak biofilm development capacity, higher expression levels of the norB gene were detected in S. aureus strains that showed strong biofilm forming capabilities. The expression levels of norB were significantly up-regulated in biofilm bacteria in comparison to planktonic bacteria. The knockout of norB gene reduced the biofilm formation ability in S. aureus. The deletion of norB gene up-regulated the expression of genes related to biofilm formation including agrD, sdrC, sdrD, agrB, agrC, fnbB, nuc, lytS, lrgA, sdrE, agrA and saeS, and down-regulated the expression of genes related to biofilm formation including clfA, icaR, sarA and rot. In conclusion, the efflux pump norB gene serves as a crucial role in the production of biofilm, thus rendering it a promising avenue for biofilm suppression.},
}

@article {pmid39566588,
year = {2024},
author = {Bamberger, MH},
title = {Editorial Comment on Indwelling Urological Devise Biofilm Composition and Characteristics in the Presence and Absence of Infection.},
journal = {Urology},
volume = {},
number = {},
pages = {},
doi = {10.1016/j.urology.2024.11.016},
pmid = {39566588},
issn = {1527-9995},
}

@article {pmid39566460,
year = {2024},
author = {Xia, L and Wang, J and Chen, M and Li, G and Wang, W and An, T},
title = {Biofilm formation mechanisms of mixed antibiotic-resistant bacteria in water: Bacterial interactions and horizontal transfer of antibiotic-resistant plasmids.},
journal = {Journal of hazardous materials},
volume = {481},
number = {},
pages = {136554},
doi = {10.1016/j.jhazmat.2024.136554},
pmid = {39566460},
issn = {1873-3336},
abstract = {Over 95 % of bacteria on water supply pipeline surfaces exist in biofilms, which are hotspots for antibiotic resistance gene (ARG) transmission. This study established mixed biofilm culture systems on a metal iron substrate using Escherichia coli: antibiotic-sensitive bacteria (ASB) and antibiotic-resistant bacteria (ARB). The growth rate and extracellular polymeric substances (EPS) content of mixed biofilm surpassed single-species biofilms due to synergistic interactions among different bacteria. However, the composition of mixed biofilms formed by ASB and ARB became unstable after 72 h, linked to reduced polysaccharide proportions in EPS and inter-bacterial competition. The bacterial composition and conjugative transfer frequency of ARGs in mixed biofilms indicate that biofilm formation significantly enhances horizontal transfer of ARGs. Notably, the conjugative transfer frequency of the mixed biofilm formed by two ARB increased 100-fold within five days. In contrast, the conjugative transfer frequency in the mixed biofilm formed by ASB and ARB was unstable; inter-bacterial competition led to plasmid loss associated with horizontal transfer of ARGs, ultimately resulting in biofilm shedding. Furthermore, genes associated with ARG transfer and biofilm growth up-regulated by 1.5 - 6 and 2 - 7 times, respectively, in mixed biofilm. These findings highlight a mutually reinforcing relationship between biofilm formation and horizontal ARG transmission, with significant environmental implications.},
}

@article {pmid39566251,
year = {2024},
author = {Yao, S and Chen, Y and Zhang, X and Dong, Z},
title = {Enhanced corrosion resistance and biofilm inhibition of TC4 with slight Cu addition against marine Pseudomonas aeruginosa.},
journal = {Bioelectrochemistry (Amsterdam, Netherlands)},
volume = {162},
number = {},
pages = {108852},
doi = {10.1016/j.bioelechem.2024.108852},
pmid = {39566251},
issn = {1878-562X},
abstract = {Ti-6Al-4V (TC4) alloy is widely utilized as the structural material in marine industries owing to its low density, high specific strength, and favorable corrosion resistance. However, as biofouling drastically alters, some reported the major deleterious effect of bacteria has imposed a challenge to improve microbiologically influenced corrosion (MIC) resistance. A further opportunity for solving this problem is Cu micro-alloying, which was inspired by adding Cu for biomedical applications. Herein, a Ti-6Al-4V alloy with slight Cu addition (TC4-Cu) was exposed to 2216E media inoculated with Pseudomonas aeruginosa (P. A.), and then investigated compared to TC4. TC4-Cu exhibits lower corrosion current, more denser passive film, and lower weight loss with weaker pitting (a maximum pitting depth of 0.2 μm), compared to TC4 with a maximum pitting crater depth of 9.6 μm. Those demonstrated that the presence of Cu significantly improved the MIC resistance, and inhibited the proliferation of P. A., leading to a good antimicrobial efficacy against marine P. A. Moreover, besides the well-known bactericidal role, Cu ions were transferred to form Cu2O and CuO, constituting protective corrosion products, and thus improving the anti-microbial properties of TC4-Cu.},
}

@article {pmid39562179,
year = {2024},
author = {Xu, L and Lu, B and Xie, K and Fan, W and Fang, S and Zhu, J and Yang, J and Xu, B},
title = {Photothermal Nano-Immunotherapy Against Methicillin-Resistant Staphylococcus aureus (MRSA) Biofilm Infections.},
journal = {Advanced healthcare materials},
volume = {},
number = {},
pages = {e2403318},
doi = {10.1002/adhm.202403318},
pmid = {39562179},
issn = {2192-2659},
support = {2022CCZC02//Traditional Chinese Medicine Inheritance Innovation Research project in Anhui Province/ ; 2022AH051251//Anhui Provincial Scientific Research Compilation Project/ ; 2022AH010076//Anhui Provincial Scientific Research Compilation Project/ ; 2023AH053407//Anhui Provincial Scientific Research Compilation Project/ ; 2408085MH197//Natural Science Foundation project of Anhui Province/ ; },
abstract = {Methicillin-resistant Staphylococcus aureus (MRSA) biofilm infections are a prevalent type of biofilm-associated infection with a poor prognosis and antibiotic resistance. The senescence of immune cells in the immune microenvironment contributes to biofilm formation. In this study, Ti3C2 MXene-PVA nanosheets loaded with metformin (Met@TiC) are developed for the treatment of MRSA biofilm infections. Nanosheets utilize near-infrared light to induce photothermal effects and provide direct bactericidal activity against biofilm structures. Met, which is known for its anti-inflammatory and anti-senescence properties, modulates immune responses by revitalizing the function of senescent macrophages within the biofilm microenvironment, thereby enhancing their phagocytic and biofilm-eradicating capabilities. The efficacy of this nanoplatform both in vitro and in an MRSA biofilm infection mouse model, demonstrating its potential as a photothermal nanoimmunotherapy for combating MRSA biofilm infections is validated. In summary, the Met@TiC nanoplatform offers a significant alternative to clinical solutions for MRSA biofilm infections.},
}

@article {pmid39562098,
year = {2025},
author = {Tian, X and Hu, H and Fan, L and Yang, J and Zhao, H and Zhang, L and Hu, D and Hao, G and Du, F and Wang, P},
title = {Smart β-cyclodextrin-dominated helical supramolecular dendritic assemblies improve the foliar affinity and biofilm disruption for treating alarming bacterial diseases.},
journal = {Carbohydrate polymers},
volume = {348},
number = {Pt A},
pages = {122823},
doi = {10.1016/j.carbpol.2024.122823},
pmid = {39562098},
issn = {1879-1344},
mesh = {*Biofilms/drug effects ; *beta-Cyclodextrins/chemistry/pharmacology ; *Anti-Bacterial Agents/pharmacology/chemistry ; Dendrimers/chemistry/pharmacology ; Plant Leaves/chemistry ; Animals ; },
abstract = {Recent outbreaks of alarming bacterial diseases have significantly impacted global agricultural productivity. Conventional bactericides exhibit certain limitations in efficiently impeding biofilm formation and annihilating biofilm-dispersed pathogens, and often expose to high off-target movement during foliar spraying. Here, we produce an innovative helical dendrimer-like supramolecular material (PhA28@β-CD) assembled by a bioactive small-molecule 2-chlorophenylisopropanolamine (PhA28) and β-cyclodextrin (β-CD) through host-guest recognition principle. In this system, the advisable optimization by a macrocyclic oligosaccharide-β-CD significantly enhances the water-solubility, biocompatibility, and bioavailability of PhA28. At a low-dose of 6.8 μg/mL, PhA28@β-CD discloses an outstanding biofilm disruption rate of 82.4 %, notably exceeding that of PhA28 (60.6 %), which thereby reduces the biofilm-associated virulence. Meanwhile, the self-assembled PhA28@β-CD possesses superior wetting and dispersing properties on hydrophobic leaves, leading to effective foliar deposition and prolong retention of active components. In vivo studies reveal that PhA28@β-CD exhibits superior curative (66.0 %) and protective (72.6 %) activities against citrus canker at 200 μg/mL, markedly surpassing those of the existing bactericide thiodiazole‑copper (46.8 % and 52.2 %) and single PhA28. This material also has broad-spectrum control efficiency (53.0 % ~ 59.5 %) against rice bacterial blight. This research lays the groundwork for developing carbohydrate-optimized multifunctional dendrimer-like assemblies aimed at disrupting biofilms and improving sustained bioavailability to combat bacterial diseases.},
}

*Biofilms/drug effects
*beta-Cyclodextrins/chemistry/pharmacology
*Anti-Bacterial Agents/pharmacology/chemistry
Dendrimers/chemistry/pharmacology
Plant Leaves/chemistry
Animals

@article {pmid39561505,
year = {2024},
author = {Bellavita, R and Casciaro, B and Nocerino, V and Palladino, S and Loffredo, MR and Dardano, P and De Stefano, L and Falcigno, L and D'Auria, G and Galdiero, S and Falanga, A},
title = {Myxinidin-analogs able to sequester Fe(III): Metal-based gun to combat Pseudomonas aeruginosa biofilm.},
journal = {Journal of inorganic biochemistry},
volume = {263},
number = {},
pages = {112774},
doi = {10.1016/j.jinorgbio.2024.112774},
pmid = {39561505},
issn = {1873-3344},
abstract = {Bacteria have developed a tendency to form biofilms, where bacteria live in organized structures embedded in a self-produced matrix of DNA, proteins, and polysaccharides. Additionally, bacteria need iron(III) as an essential nutrient for bacterial growth and secrete siderophore groups that sequester it from the environment. To design a molecule able both to inhibit the bacteria and to sequester iron, we developed two hydroxamate-based peptides derived from an analog (WMR-4), previously developed in our lab, of the antimicrobial peptide myxinidin. In detail, we proposed a combination of WMR-4 with the hydroxamic acid resulting in the peptides WMR-7 and WMR-16 which differ for the length of the linker between the antimicrobial moiety and the siderophore. Both peptides were characterized through a set of different biophysical experiments to investigate their ability to sequester Fe[3+]. The peptide‑iron(III) complexes were studied through the UV-visible spectroscopy in organic solvent to eliminate water competition, and in acidic water to avoid iron precipitation. The complexes were also characterized by performing electrochemistry, circular dichroism and NMR spectroscopy experiments. In addition, we demonstrated the ability of peptide‑iron(III) complexes to inhibit the biofilm of Pseudomonas aeruginosa and to have an impact on the cell motility. This metal-based approach consisting in a hydroxamic acid conjugation represents a promising strategy to enhance the antibiofilm activity of antimicrobial peptides against one of most dangerous bacteria such as Pseudomonas aeruginosa.},
}

@article {pmid39561392,
year = {2024},
author = {Basnet, A and Chand, AB and Bajracharya, S and Shrestha, MR and Shrestha, S and Tamang, B and Dulal, M and Pokhrel, N and Shrestha, LB},
title = {Biofilm Formation and Plasmid-Mediated Quinolone Resistance Genes at Varying Quinolone Inhibitory Concentrations in Quinolone-Resistant Bacteria Superinfecting COVID-19 Inpatients.},
journal = {The American journal of tropical medicine and hygiene},
volume = {},
number = {},
pages = {},
doi = {10.4269/ajtmh.24-0276},
pmid = {39561392},
issn = {1476-1645},
abstract = {The likelihood of antimicrobial failure in COVID-19 patients with bacterial superinfection arises from both phenotypic (biofilms) and genotypic mechanisms. This cross-sectional study aimed to determine the inhibitory concentrations of quinolones-nalidixic acid, norfloxacin, ciprofloxacin, ofloxacin, and levofloxacin-in biofilm formers (minimum biofilm inhibitory concentration [MBIC]) and nonformers (minimum inhibitory concentration [MIC]) and correlate inhibitory concentrations with plasmid-mediated quinolone resistance (PMQR) genes in quinolone-resistant bacteria isolated from COVID-19 inpatients. Quinolone-resistant bacteria (n = 193), verified through disc diffusion, were tested for quinolone inhibitory concentrations using broth microdilution and biofilm formation using microtiter plate methods. The polymerase chain reaction was used to detect PMQR genes. Study variables were analyzed using SPSS v.17.0, with a significance level set at P <0.05. MIC-to-MBIC median fold increases for ciprofloxacin, ofloxacin, and levofloxacin were 128 (2-8,192), 64 (4-1,024), and 32 (4-512) in gram-positive cocci (GPC, n = 43), respectively, whereas they were 32 (4-8,192), 32 (4-2,048), and 16 (2-1,024) in fermentative gram-negative bacilli (F-GNB, n = 126) and 16 (4-4,096), 64 (2-64), and 16 (8-512) in nonfermentative gram-negative bacilli (NF-GNB, n = 24). In biofilm-forming F-GNB and NF-GNB, qnrB (10/32 versus 3/10), aac(6')-Ib-cr (10/32 versus 4/10), and qnrS (9/32 versus 0/10) genes were detected. A 32-fold median increase in the MIC-to-MBIC of ciprofloxacin was significantly (P <0.05) associated with qnrA in F-GNB and qnrS in NF-GNB. Biofilms formed by F-GNB and NF-GNB were significantly associated with the aac(6')-Ib-cr and qnrS genes, respectively. Nearly one-third of the superinfecting bacteria in COVID-19 patients formed biofilms and had at least one PMQR gene, thus increasing the need for quinolones at higher inhibitory concentrations.},
}

@article {pmid39559081,
year = {2024},
author = {Calo', L and Rodolico, D and Galli, J},
title = {Direct Biofilm Visualization in Voice Prosthesis.},
journal = {Indian journal of otolaryngology and head and neck surgery : official publication of the Association of Otolaryngologists of India},
volume = {76},
number = {6},
pages = {6090-6091},
pmid = {39559081},
issn = {2231-3796},
}

@article {pmid39557280,
year = {2024},
author = {Reis, FN and Câmara, JVF and Abuna, G and Moraes, SM and da Silva, NDG and Ventura, TMO and Araujo, TT and Rodrigues, CMVBF and Pardi, V and Murata, RM and Buzalaf, MAR},
title = {Resveratrol alters oral biofilm in vitro and in vivo.},
journal = {Journal of dentistry},
volume = {},
number = {},
pages = {105466},
doi = {10.1016/j.jdent.2024.105466},
pmid = {39557280},
issn = {1879-176X},
abstract = {OBJECTIVE: To evaluate the ability of resveratrol to reduce dental caries in vitro and in vivo.

METHODS: In part 1, a microcosm biofilm protocol was employed. One hundred twenty-six bovine enamel specimens were treated with: Resveratrol (50, 100, 200, 400 µg/mL), Phosphate buffered saline (negative control), Dimethyl sulfoxide (negative control) and 0.12% Chlorhexidine (positive control). The biofilm was produced from the saliva of 10 volunteers, under 0.2% sucrose exposure for 5 days, and daily treated with the solutions (1 min). At the end of the experimental period, resazurin and viable plate count assays were performed. Enamel demineralization was evaluated by transverse microrradiography (TMR). In part 2, 12 volunteers participated in a triple-blind crossover protocol for 7 weeks, according to the following treatments: 1) 100 mg/L resveratrol; 2) 0.05% NaF (226 mg/L F); 3) 100 mg/L resveratrol + 0.05% NaF; 4) Deionized water (negative control). Biofilm samples were collected from both sides of the mouth 12 h after the use of the solutions.

RESULTS: Resveratrol at 50 and 200 µg/mL significantly reduced biofilm metabolic activity and mutans streptococci, respectively. Chlorhexidine was an effective treatment to significantly reduce all parameters, being an important antimicrobial and anticaries agent in vitro. Resveratrol alone or associated with NaF modulates several caries-associated bacteria in vivo.

CONCLUSION: The present study represents the first step regarding the use of resveratrol within the concept of acquired enamel pellicle and biofilm engineering to prevent dental caries.},
}

@article {pmid39557100,
year = {2024},
author = {Fan, XY and Zhou, SL and Yang, Y and Cao, SB and Niu, Y and Zheng, MY and Zhao, JR},
title = {Impact of carbon/nitrogen ratio on sequencing batch biofilm reactors initiated with different seed sludges for treating actual mariculture effluents.},
journal = {Bioresource technology},
volume = {417},
number = {},
pages = {131838},
doi = {10.1016/j.biortech.2024.131838},
pmid = {39557100},
issn = {1873-2976},
abstract = {The impact of carbon/nitrogen (C/N) ratio on sequencing batch biofilm reactor (SBBR) initiated with different seed sludges for treating actual mariculture effluent was explored. Increasing the C/N ratio significantly enhanced the nitrogen removal efficiency, achieving average removal efficiency of 95% for ammonia nitrogen and 73% for total nitrogen at ratio of 30, while the impact of seed sludge was minimal. High C/N ratio promoted the secretion of tightly bound extracellular polymeric substances (TB-EPS), which showed significant correlation with nitrogen removal. Interactions between bacteria and archaea were enhanced and conditionally rare or abundant taxa were the keystone taxa. High C/N ratio inhibited the relative abundance of ammonia-oxidizing archaea (Candidatus_Nitrosopumilus) and bacteria (Nitrosomonas), but promoted the heterotrophic nitrification-aerobic denitrification bacteria (Halomonas). The expression of nitrogen removal functional genes significantly correlated with functional genera. This study emphasized the crucial role of high C/N ratios in biological nitrogen removal from actual mariculture effluent.},
}

@article {pmid39556104,
year = {2024},
author = {You, Z and Yu, H and Zhang, B and Liu, Q and Xiong, B and Li, C and Qiao, C and Dai, L and Li, J and Li, W and Xin, G and Liu, Z and Li, F and Song, H},
title = {Engineering Exopolysaccharide Biosynthesis of Shewanella oneidensis to Promote Electroactive Biofilm Formation for Liquor Wastewater Treatment.},
journal = {ACS synthetic biology},
volume = {},
number = {},
pages = {},
doi = {10.1021/acssynbio.4c00417},
pmid = {39556104},
issn = {2161-5063},
abstract = {Microbial electrochemical systems (MESs), as a green and sustainable technology, can decompose organics in wastewater to recover bioelectricity. Electroactive biofilms, a microbial community structure encased in a self-produced matrix, play a decisive role in determining the efficiency of MESs. However, as an essential component of the biofilm matrix, the role of exopolysaccharides in electroactive biofilm formation and their influence on extracellular electron transfer (EET) have been rarely studied. Herein, to explore the effects of exopolysaccharides on biofilm formation and EET rate, we first inhibited the key genes responsible for exopolysaccharide biosynthesis (namely, so_3171, so_3172, so_3177, and so_3178) by using antisense RNA in Shewanella oneidensis MR-1. Then, to explore the underlying mechanisms why inhibition of exopolysaccharide synthesis could enhance biofilm formation and promote the EET rate, we characterized cell physiology and electrophysiology. The results showed inhibition of exopolysaccharide biosynthesis not only altered cell surface hydrophobicity and promoted intercellular adhesion and aggregation, but also increased biosynthesis of c-type cytochromes and decreased interfacial resistance, thus promoting electroactive biofilm formation and improving the EET rate of S. oneidensis. Lastly, to evaluate and intensify the capability of exopolysaccharide-reduced strains in harvesting electrical energy from actual liquor wastewater, engineered strain Δ3171-as3177 was further constructed to treat an actual thin stillage. The results showed that the output power density reached 380.98 mW m[-2], 11.1-fold higher than that of WT strain, which exhibited excellent capability of harvesting electricity from actual liquor wastewater. This study sheds light on the underlying mechanism of how inhibition of exopolysaccharides impacts electroactive biofilm formation and EET rate, which suggested that regulating exopolysaccharide biosynthesis is a promising avenue for increasing the EET rate.},
}