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Bibliography on: Biofilm

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ESP: PubMed Auto Bibliography 26 Jun 2025 at 01:40 Created: 

Biofilm

Wikipedia: Biofilm A biofilm is any group of microorganisms in which cells stick to each other and often also to a surface. These adherent cells become embedded within a slimy extracellular matrix that is composed of extracellular polymeric substances (EPS). The EPS components are produced by the cells within the biofilm and are typically a polymeric conglomeration of extracellular DNA, proteins, and polysaccharides. Because they have three-dimensional structure and represent a community lifestyle for microorganisms, biofilms are frequently described metaphorically as cities for microbes. Biofilms may form on living or non-living surfaces and can be prevalent in natural, industrial and hospital settings. The microbial cells growing in a biofilm are physiologically distinct from planktonic cells of the same organism, which, by contrast, are single-cells that may float or swim in a liquid medium. Biofilms can be present on the teeth of most animals as dental plaque, where they may cause tooth decay and gum disease. Microbes form a biofilm in response to many factors, which may include cellular recognition of specific or non-specific attachment sites on a surface, nutritional cues, or in some cases, by exposure of planktonic cells to sub-inhibitory concentrations of antibiotics. When a cell switches to the biofilm mode of growth, it undergoes a phenotypic shift in behavior in which large suites of genes are differentially regulated.

Created with PubMed® Query: ( biofilm[title] NOT 28392838[PMID] NOT 31293528[PMID] NOT 29372251[PMID] ) NOT pmcbook NOT ispreviousversion

Citations The Papers (from PubMed®)

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RevDate: 2025-06-25

Shatri AMN, Bere SK, Bouman D, et al (2025)

Antimicrobial, Time-Kill Kinetics, and Biofilm Inhibition Properties of Diospyros lycioides Chewing Stick Used in Namibia Against Enterococcus faecalis.

Journal of tropical medicine, 2025:7544856.

Background: Medicinal plants are used in Namibia for oral hygiene and to treat oral diseases. Validating the content and efficacy of medicinal chewsticks used in communities helps to provide proof of concept of medicinal plants used as a complementary/alternative medicine for oral diseases. Aim: This study presents the first report on quantified phytoconstituents, antimicrobial, time-kill kinetics, and biofilm inhibition properties of Diospyros lycioides organic and aqueous extracts against Enterococcus faecalis. Methodology: Dry plant materials were ground into powder and macerated in methanol and distilled water. Different phytoconstituents were quantified by Folin-Ciocalteu colorimetric method, ferric reducing antioxidant power assay, and DPPH free radical scavenging. An antibacterial assay was performed using the agar well diffusion method and a resazurin 96-well-based assay. Kill-time assay was done at various concentrations over 4 h. Biofilm inhibition was done using the crystal violet method. Results: Higher total flavonoid, total phenol contents, and free radical scavenging abilities were reported in methanol twig extracts. Inhibition zones of 28 ± 0.82 mm, with MICs of 15.6 ± 0.00 μg/mL, are reported against E. faecalis. The bactericidal endpoint of D. lycioides organic extracts for E. faecalis was reached after 4 h of incubation at 8 × MIC (124.8 μg/mL). These were comparable to the positive control, gentamicin. The organic extracts showed ≥ 50% biofilm inhibition against root canal-infecting E. faecalis at concentrations between 7.8 and 500 μg/mL, indicating strong biofilm inhibition. Conclusion: The study demonstrated that D. lycioides crude extracts have promising antibacterial properties and can eradicate E. faecalis biofilms in root canal treatments.

RevDate: 2025-06-23

Zhang Z, Liu B, Chen W, et al (2025)

Corrigendum to "Enhancing sewer low-loss transportation by food waste microencapsulation treatment: Dual suppression of organic leaching and biofilm architecture-function for mitigating hazardous gases and blockage risks" [Water Research Volume 282 (2025) 123749].

RevDate: 2025-06-24

Lu M, Feng Q, Qin F, et al (2025)

Enhanced denitrification and fouling control in hydrogen-based membrane biofilm reactor using novel flat membrane module.

Bioresource technology, 435:132848 pii:S0960-8524(25)00814-4 [Epub ahead of print].

In hydrogen-based membrane biofilm reactors (H2-MBfR), the most critical concerns revolve removal rate and membrane fouling. This study introduces a novel flat membrane module to enhance denitrification efficiency and the operational stability of MBfR. The membrane module featured an additional layer of polyester material on outer side of the membrane. Experimental results demonstrated that membrane fouling occurred after one week, while the flocking layer extended the fouling-free operation to over eight weeks, representing an eightfold improvement at least. Low temperature and high loading were observed to impact the denitrification efficiency, although it maintained around 50 % without nitrite accumulation. Following the removal of operational disturbances, the MBfR rapidly restored with removal efficiencies reaching 93.8 % to 100 %. As the MBfR operated, microbial analysis revealed a decrease in microbial diversity, and differential expression levels of denitrification genes. The novel membrane module contributed to improving fouling control and removal flux.

RevDate: 2025-06-24
CmpDate: 2025-06-24

Şenel K, Uzun I, R Alqawasmi (2025)

An in vitro evaluation of biofilm removal from simulated root canals using sodium hypochlorite irrigation solution at various temperature settings.

PloS one, 20(6):e0325431.

BACKGROUND: Using sodium hypochlorite (NaOCl) irrigation solution at various temperatures is common for removing biofilms in root canals and the isthmus. Numerous studies have examined the impact of temperature on biofilm removal in extracted teeth. However, this study aimed to assess the effect of needle irrigation using NaOCl solution heated to different temperatures on the structure of E. faecalis biofilm in artificial teeth produced by 3D printing technology.

MATERIALS AND METHODS: The isthmus in the mesial canals of 55 artificial tooth samples, which were produced from the 3D model obtained by micro-CT of the mandibular first molars, was evaluated. The standard strain E. faecalis ATCC 19433 was used to infect artificial tooth specimens. The samples were divided into a control group and four experimental groups receiving sodium hypochlorite solutions at 21°C, 45°C, 60°C, and 150°C. Following irrigation, scanning electron microscope (SEM) imaging was conducted at varying magnifications to visualize the remaining biofilm areas in the root canals and the isthmus. The ImageJ program quantified biofilm areas in the isthmus region. Statistical analyses, including Shapiro-Wilks, Kruskal Wallis H, and t-tests, were conducted on the measurements. A p-value of < 0.05 was considered statistically significant.

CONCLUSIONS: The results did not differ between the control and 21 °C groups (p > 0.05). However, removal areas were larger in the 45°C, 60°C, and 150°C groups than in the control group (p < 0.05). No difference was observed in the biofilm removal efficiency in different isthmus regions (p > 0.05). The findings revealed that an increase in temperature enlarged the removal areas.

RevDate: 2025-06-24
CmpDate: 2025-06-24

Nishizawa M, Saleh B, Marcucio R, et al (2025)

A Unique Mouse Model for Quantitative Assessment of Biofilm Formation on Surgical Implants in Subcutaneous Abscess.

Journal of visualized experiments : JoVE.

To develop a novel biomaterial with antibacterial properties for orthopedic surgical procedures, establishing an experimental animal model of implant-related infections that closely mimics the pathological state is crucial. Additionally, a quantitative comparison with control samples is required to assess biofilm formation on materials. However, current animal models, which involve implanting each individual with a single material, may yield inconsistent outcomes due to the heterogeneity of infection status among subjects. Furthermore, accurately quantifying biofilm formation on materials in vivo remains challenging, and the findings may lack reliability. To address these issues, this study demonstrated a unique mouse model of implant-related infection that enables the simultaneous incubation of two implants with bacteria in an enclosed environment within a single mouse, forming an encapsulated subcutaneous abscess. A mature air pouch was initially created beneath the skin of the back. Two stainless steel wires were connected and placed into the pouch, followed by the inoculation of Xen 36, a bioluminescent strain of Staphylococcus aureus. By 14 days after inoculation, a subcutaneous abscess had formed around the wires. The biofilm was completely removed from the surface of each wire, and the dissolved bacterial suspensions were accurately measured using optimized methods to assess biofilm formation on the implant, determine colony-forming units, and perform quantitative polymerase chain reaction analysis. By leveraging the lux operon of the bioluminescent bacteria, the relative expression levels of luxA and 16S rRNA were used to determine the bacterial load within the biofilm on each wire. This optimized comparative analytical approach enables precise assessments of biofilm formation on two wires under uniform infection conditions within a single mouse model and may facilitate the advancement of biomaterials with antibacterial properties.

RevDate: 2025-06-24
CmpDate: 2025-06-24

Abban MK, Ayerakwa EA, A Isawumi (2025)

Biofilm and surface-motility profiles under polymyxin B stress in multidrug-resistant KAPE pathogens isolated from Ghanaian hospital ICUs.

Experimental biology and medicine (Maywood, N.J.), 250:10350.

The threat of antimicrobial resistance in Ghana is increasing with the recent emergence of KAPE pathogens (K. pneumoniae, A. baumannii, P. aeruginosa and Enterobacter species) from the hospital environment. As opportunistic pathogens, KAPE leverage the formation of biofilms and swarms to survive stringent environmental conditions. As research continues to investigate approaches that bacteria employ to exacerbate infection, this study explored biofilm and swarm formation in MDR KAPE pathogens under polymyxin B stress emerging from Ghanaian hospitals. The antimicrobial susceptibility profile of KAPE pathogens to conventional antibiotics and polymyxin B was investigated via antibiotic disk diffusion and broth microdilution assays. Biofilm inhibition and eradication assays, swarm motility and a resazurin-based metabolic assay were used to profile bacterial phenotypic characteristics under polymyxin B stress. The strains exhibited resistance to the tested antibiotics with a high level of resistance to polymyxin B (PMB) (≥512 μg/mL). Additionally, the strains formed biofilms and bacterial swarms at 37°C. In the presence of PMB (≥512 μg/mL), KAPE pathogens formed swarms with no significant reduction in bacterial swarms at 1,048 μg/mL. Biofilm was observed for all strains with PMB neither inhibiting nor eradicating at high PMB (2048 μg/mL). Additionally, there were no significant differences in the phenotypic and antimicrobial susceptibility profiles of clinical and environmental KAPE pathogens from Ghanaian ICUs. Overall, the study established that clinical and environmental KAPE pathogens from Ghanaian ICUs exhibit adaptive phenotypic and resistance characteristics that could potentially enhance bacterial survival during host colonization and infection. This could undermine treatment strategies and pose public health challenges in Ghana.

RevDate: 2025-06-23

Thibodeau AJ, Mouchet F, Nguyen VX, et al (2025)

Experimental assessment of antibiotic resistance in a Biofilm - Grazer system.

Environmental pollution (Barking, Essex : 1987) pii:S0269-7491(25)01055-3 [Epub ahead of print].

Antimicrobial resistance (AMR) is a growing global health threat, with environmental compartments such as soil, water, and biofilms playing key roles in the dissemination and persistence of resistance genes. In this study, we explored the dynamics of AMR within a controlled Biofilm-Grazer system using Xenopus laevis larvae and biofilms A and B collected from two distinct rivers in Occitanie, France (collected respectively upstream from the large city of Toulouse and downstream from a wastewater treatment plant). The objective of the study was to investigate bacterial interactions between gut microbiota and biofilms, as well as the modulation of ARG (Antibiotic Resistance Gene) abundance and diversity over a 12-day period. Results showed a decrease of resistome in Xenopus gut microbiota feeding on both biofilms compared to feeding on commercial feed. In addition, an increase of resistome of Biofilm B compared to Biofilm A was observed. Procruste analysis and Pearson's correlations revealed a link between bacterial communities changes and ARG abundances in biofilms. Rhodobacter genus could be an ARG host shared between compartments. Furthermore, bacterial immigration predominantly occurred from the gut to the biofilms, with both biofilms acting as reservoirs for ARGs. Notably, Biofilm B, collected from a more polluted river, demonstrated a higher relative abundance of aac3-IVa resistance genes in the gut microbiota of larvae, compared to Biofilm A and a higher immigration rate from biofilm to gut. These findings highlight the complexity of interactions between biofilm communities and the gut microbiota, which may influence AMR dissemination.

RevDate: 2025-06-25

Peng P, Yan X, Chen L, et al (2025)

Electroactive biofilm enhances synergistic degradation of sulfamethoxazole and roxarsone in actual livestock wastewater: extracellular electron transfer drives metabolic network remodeling.

Environmental research, 284:122173 pii:S0013-9351(25)01424-0 [Epub ahead of print].

Livestock wastewater is characterized by high concentrations of organic matter and diverse antibiotics. A major challenge in its anaerobic treatment is the effective degradation and thorough removal of coexisting antibiotic contaminants. In this study, an external voltage was applied to establish an electroactive biofilm, thereby enhancing the co-metabolic degradation of sulfamethoxazole and roxarsone. Application of +0.6 V (Ag/AgCl) increased the 72 h TOC removal efficiency to 52.1 %. At the same time, sulfamethoxazole and roxarsone removal efficiencies reached 90.8 % and 100 %, respectively. The results from liquid chromatography-mass spectrometry (HPLC-MS/MS) and density functional theory calculations revealed sulfamethoxazole degradation pathways: N-O bond cleavage and hydroxylation. Roxarsone degradation primarily involved nitro group reduction and C-As bond cleavage. The pharmacophore of sulfamethoxazole was effectively removed, and inorganic arsenic from roxarsone degradation was efficiently immobilized. Toxicity analysis confirmed that the electroactive biofilm notably reduced toxic intermediate accumulation. Elevated concentrations of NADH and ATP in the electroactive biofilm indicated enhanced microbial substrate metabolism and generation of more electron donors. The higher absolute abundance of the sulfamethoxazole degradation gene (SadABC) in the electroactive biofilm indicated that sulfamethoxazole degrading enzyme (sadABC) gained more electrons. Microbiome analysis revealed the upregulation of genes linked to extracellular electron transfer, the tricarboxylic acid (TCA) cycle, nitro-reduction, and sulfate reduction pathway, confirming the electroactive biofilm enhances substrate metabolism and co-metabolic antibiotic degradation. Electroactive biofilm offers a viable strategy for antibiotic removal in livestock wastewater.

RevDate: 2025-06-23

Zhang H, Jiang H, Jin L, et al (2025)

Self-corroding microelectrolysis enhanced membrane aeration electroactive biofilm for antibiotic and antibiotic resistance gene reduction.

Bioresource technology pii:S0960-8524(25)00821-1 [Epub ahead of print].

A three-dimensional bioelectrochemical system was developed by coupling self-corrosive Fe/C microelectrodes with a membrane-aerated electroactive biofilm reactor (IC-MAEBR) to enhance antibiotic and antibiotic resistance gene (ARG) reduction. The IC-MAEBR significantly enriched aromatic proteins as dominant fluorescent components in cathode biofilms, while exhibiting an elevated α-helix to (β-sheet + random coil) (62.8 %), enhanced biofilm dense. Besides, the coordinated action of applied potential and microelectrolysis reduced sul1 and sul2 abundances in cathode biofilms by -2.6 log2 and -1.6 log2, respectively, primarily through host microorganism inactivation. Although higher potential differences (0.75 V) narrowed SMX removal difference between membrane-aerated electroactive biofilm reactors (MAEBR) and IC-MAEBR, IC-MAEBR demonstrated superior performance at lower potentials (0.5 V), achieving rapid SMX degradation within 12 h and maintained accelerated removal kinetics even post-discharge cycles, outperforming MABR and MAEBR by 4.2 μg/L/h and 9.7 μg/L/h, respectively. This study provides new insights into microelectrolysis enhanced electroactive-biofilm in antibiotics and ARGs removal.

RevDate: 2025-06-23

Pu Y, Feng F, Hou Y, et al (2025)

Impact of yeast extract on bacterial metabolism and nickel microbiologically influenced corrosion: Insights into medium optimization and biofilm electron transfer mechanism.

Bioelectrochemistry (Amsterdam, Netherlands), 166:109027 pii:S1567-5394(25)00130-6 [Epub ahead of print].

Yeast extract (YE) serves as a complex nutrient source and plays a pivotal role in the formation and development of microbial biofilms. This work elucidates the critical role of YE in modulating the metabolic activity of Desulfovibrio vulgaris, characteristics of passive films, and the associated microbiologically influenced corrosion (MIC) behavior of nickel (Ni). The presence of YE suppresses corrosion processes linked to extracellular electron transfer (EET) by reducing the necessity for D. vulgaris to directly extract electrons from Ni. In the absence of YE, a greater number of D. vulgaris cells adhere to the Ni surface, forming biofilms with an increased reliance on EET from Ni, thereby exacerbating localized corrosion. This is evidenced by increased weight loss, deeper pitting, and elevated localized corrosion current density, establishing a clear correlation between YE availability and the mitigation of EET-mediated MIC. Meanwhile, YE mitigates EET-driven corrosion by regulating the biofilm structure, facilitating the formation of a protective layer, and modifying the passive film on Ni. A key implication of this work is the reconsideration of YE as a universal nutrient in MIC research, emphasizing the need for caution when using YE in MIC studies that focus on EET-driven mechanisms.

RevDate: 2025-06-24
CmpDate: 2025-06-24

Saci S, Houali K, Schena R, et al (2025)

Phenotypic and genotypic characterization of biofilm-producing avian pathogenic Escherichia coli (APEC) isolates from Algerian poultry: associations between antimicrobial resistance and virulence genes.

Veterinary research communications, 49(4):232.

Avian colibacillosis, caused by avian pathogenic Escherichia coli (APEC), represents a major threat to the poultry industry, leading to significant economic losses. This study aimed to characterize selected biofilm-producing APEC strains isolated from diseased chickens in the Tizi-Ouzou region of Algeria and to explore potential associations between antimicrobial resistance and the presence of virulence factors. Twenty-four confirmed biofilm-producing E. coli isolates were analyzed for serotype distribution, antimicrobial resistance patterns and virulence gene profiles. While none belonged to the O157 serogroup, all isolates demonstrated concerning resistance profiles, with high rates observed for tetracycline (83.3%), ampicillin (75%), and ciprofloxacin (62.5%). Notably, 40% of the strains exhibited biofilm-forming capability, predominantly showing weak to moderate production levels.Virulence gene profiling revealed traT, bcsA, and csgA as nearly ubiquitous (95.8%), with fimH present in 83.3% of isolates. Intermediate prevalence was noted for iutA (62.5%), fliC (45.8%), and agn43 (33.3%), while fyuA (29.2%) and several other virulence markers (kpsMT II, papC, cnf1, ibeA) occurred at lower frequencies (< 10%). Statistical analysis identified significant correlations between virulence gene content and phenotypic characteristics, including a positive association between virulence gene number and biofilm intensity (p < 0.05). Moreover, the fimH gene showed a strong positive correlation with resistance to the antibiotic nalidixic acid. Resistance to β-lactam antibiotics (cefotaxime, cefepime, aztreonam) was positively correlated (p < 0.05) with papC and ibeA, but negatively correlated with csgA. These findings underscore the complex interplay between antimicrobial resistance and virulence in Algerian biofilm-producing APEC strains, highlighting the need for enhanced surveillance programs and tailored intervention strategies. This study provides critical baseline data for developing effective control measures against colibacillosis poultry production systems.

RevDate: 2025-06-23

Olivan-Muro I, Guío J, Alonso-Tolo G, et al (2025)

Towards the control of biofilm formation in Anabaena (Nostoc) sp. PCC7120: novel insights into the genes involved and their regulation.

The New phytologist [Epub ahead of print].

Cyanobacteria are major components of biofilms in light-exposed environments, contributing to nutrient cycling, nitrogen fixation and global biogeochemical processes. Although nitrogen-fixing cyanobacteria have been successfully used in biofertilization, the regulatory mechanisms underlying biofilm formation remain poorly understood. In this work, we have identified 183 novel genes in Anabaena sp. PCC7120 potentially associated with exopolysaccharide (EPS) biosynthesis and biofilm formation, unveiling conserved and novel regulatory connections shared with phylogenetically distant bacteria. Anabaena possesses homologues of two-component systems such as XssRS and ColRS from Xanthomonas spp., and AnCrpAB from Methylobacillus, suggesting that these homologues play essential or advantageous roles in biofilm formation across diverse bacterial lineages. Additionally, Anabaena features homologues of several proteins exhibiting the GG-secretion motif typical of small proteins required for biofilm formation in unicellular cyanobacteria. A wide array of biofilm-related genes in Anabaena, including major gene clusters participating in the synthesis and translocation of EPS and key regulatory proteins involved in the control of biofilms in other bacteria are modulated by ferric uptake regulator proteins. These findings link the control of biofilm formation in Anabaena to environmental cues such as metal availability, desiccation and nitrogen levels, providing new insights to improve the use of nitrogen-fixing cyanobacterial biofilms in sustainable agriculture and environmental management.

RevDate: 2025-06-24
CmpDate: 2025-06-24

Ranava D, Lander SM, Kuan SY, et al (2025)

A promiscuous Bcd amino acid dehydrogenase promotes biofilm development in Bacillus subtilis.

NPJ biofilms and microbiomes, 11(1):112.

Glutamate dehydrogenase (GDH) resides at the crossroads of nitrogen and carbon metabolism, catalyzing the reversible conversion of L-glutamate to α-ketoglutarate and ammonium. GDH paralogs are ubiquitous across most species, presumably enabling functional specialization and genetic compensation in response to diverse conditions. Staphylococcus aureus harbors a single housekeeping GDH (GudB), whereas Bacillus subtilis encodes both a major and a minor GDH, GudB and RocG, respectively. In an unsuccessful attempt to identify an alternative GDH in S. aureus, we serendipitously discovered previously unrecognized GDH activity in two metabolic enzymes of B. subtilis. The hexameric Val/Leu/Ile dehydrogenase Bcd (formerly YqiT) catabolizes branched-chain amino acids and to a lesser extent glutamate using NAD[+] as a cofactor. Removal of gudB and rocG unmasks the dual NAD(P)[+]-dependent GDH activity of RocA, which otherwise functions as a 3-hydroxy-1-pyrroline-5-carboxylate dehydrogenase. Bcd homologs are prevalent in free-living and obligate bacteria but are absent in most, if not all, staphylococci. Despite low sequence homology, Bcd structurally resembles the GudB/RocG family and can functionally compensate for the loss of GudB in S. aureus. Bcd is essential for the full maturation of biofilms. B. subtilis lacking GDHs exhibits severe impairments in rugose architecture and colony expansion of biofilms. This study underscores the importance of metabolic redundancy and highlights the critical role of substrate promiscuity in GDHs during biofilm development.

RevDate: 2025-06-23

Yawen Z, Tiantian S, Yangyang S, et al (2025)

Dodecylmethylaminoethyl methacrylate inhibits the growth of Candida albicans and Enterococcus faecalis biofilm and the formation of osteoclast.

Archives of oral biology, 177:106331 pii:S0003-9969(25)00159-1 [Epub ahead of print].

OBJECTIVES: This study aimed to evaluate the antimicrobial ability on the dual-species biofilm formed by C. albicans and E. faecalis and osteoclysis inhibition of DMAEM.

DESIGN: DMAEM monomer was used to evaluate the antmicrobial ability on the dual-species biofilm of C. albicans and E. faecalis by biomass quantification, Scanning electron microscope and confocal laser scanning microscopy scanning, and RT-qPCR. The biosafty and inhibition ability on the dual-species biofilm and osteoclysis of the experimental root canal sealers containing DMAEM was tested by biomass quantification, Cell Counting kit-8, tartrate-resistant acid phosphatase staining, flow cytometry analysis, and RT-qPCR.

RESULTS: The biomass of the dual-species biofilm formed by C. albicans and E. faecalis was significantly decreased by 26.3-51.3 % under 8-256 μg/mL DMAEM. 8 μg/mL DMAEM could reduce E. faecalis's survival rate to 77.4 % (p < 0.001) and down-regulated its virulence gene expression. Meanwhile, the mycelium count proportion of C. albicans in the dual-species biofilm was reduced from 50 % to 0 % (p < 0.0001). The experimental sealers with DMAEM content could also decrease the survival rate of C.albicans and E.faecalis in the dual-species biofilm. Moreover, the elution of experimental root canal sealers containing ≤ 2.5 % DMAEM was biosafe and improved 81.0 % (p < 0.05) osteoclastic inhibition compared with it of unmodified sealers at least.

CONCLUSIONS: The antimicrobial ability on the dual-species biofilm formed by C. albicans and E. faecalis and osteoclastic inhibition of DMAEM suggested its potential clinical application of DMAEM in the treatment of periapical inflammation.

RevDate: 2025-06-23

Zhang S, Li Y, Jiang L, et al (2025)

Insights on the characteristics of plastic surface degradation and biofilm microorganisms: Exploring the impacts of three aerobic composting (AC) as well as UV irradiation and cycles of freeze-thaw (CFTs).

Journal of hazardous materials, 495:138960 pii:S0304-3894(25)01876-X [Epub ahead of print].

Organic fertilizers applied to soil often contain significant amounts of plastics, which typically undergo a process of aerobic composting (AC) that induces specific physical and chemical changes on their surfaces. In this study, we simulated the environmental actions of AC source plastic film under typical soil environmental exposure, exploring how AC affects the response of plastics to ultraviolet (UV) radiation and cycles of freeze-thaw (CFTs). The results showed that varying composting conditions significantly impacted the fungal and bacterial community structures on the plastic surface; and plastic degradation under AC present various surface properties, including embrittlement, wear, corrosion, and reduced transparency, with specific yellowing and breakage, and strong microbial adhesion. UV exposure exacerbated the degradation of plastics sourced from AC. Plastics subjected to both AC and UV displayed significant changes after experiencing intense stress from CFTs. The structures of polyethylene (PE) and polylactic acid (PLA) were severely disrupted, resulting in the formation of powder or debris. Moreover, PLA and polyvinyl chloride (PVC) showed slightly reduced yellowing and unsaturation, while releasing total dissolved solids (TDS), micro/nanoplastics and additives. This study highlights the distinct characteristics of plastic pollution originating from AC processes associated with organic fertilizer land-use.

RevDate: 2025-06-23

Adams CO, Campbell JA, Zhang B, et al (2025)

Legionella pneumophila type II secretome reveals a polysaccharide deacetylase that impacts intracellular infection, biofilm formation, and resistance to polymyxin- and serum-mediated killing.

mBio [Epub ahead of print].

Prior analyses suggested that the type II secretion system (T2SS) of Legionella pneumophila secretes ≥47 proteins beyond its 26 known substrates. Upon examination of mutants of wild-type strain 130b that lack those exoproteins most conserved across the Legionella genus, we discovered that protein "06635" majorly promotes L. pneumophila replication within amoebae. Immunoblotting, proteomics, and whole-cell enzyme-linked immunosorbent assay (ELISA) confirmed that 06635 exists in culture supernatants and on the bacterial outer surface and does so in a T2SS-dependent manner. Bioinformatic analyses identified 06635 as a novel member of the carbohydrate esterase family 4, whose members deacetylate bacterial surface polysaccharides, peptidoglycan, chitins, and/or xylans. Given 06635's T2SS-dependent secretion, low-level amino acid similarity to known peptidoglycan deacetylases, and the unaltered lysozyme resistance of a 06635 mutant, we pursued the hypothesis that 06635 deacetylates a polysaccharide on L. pneumophila's surface. Supporting this, the 06635 mutant exhibited increased binding to both wheat germ agglutinin (i.e., more surface N-acetylglucosamine) and antibodies that recognize acetylated lipopolysaccharide (LPS). Nuclear magnetic resonance (NMR) analysis of isolated mutant vs wild-type LPS confirmed that 06635 promotes LPS deacetylation. Thus, we designated 06635 as PdaA, for polysaccharide deacetylase A. Compatible with its altered surface, the pdaA mutant showed greater autoaggregation, increased biofilm formation, and heightened sensitivity to both polymyxin and human serum. Thus, we hypothesize that, following its secretion via the T2SS, PdaA deacetylates LPS, and perhaps other moieties, impacting many significant processes. While defining PdaA, we identified many more putative substrates of the L. pneumophila T2SS, bringing the size of the T2SS output to approximately 120.IMPORTANCELegionella pneumophila is the principal cause of Legionnaires' disease, an increasingly common form of pneumonia. Although prior work demonstrated that the bacterium utilizes its type II protein secretion system (T2SS) to survive in aquatic environments and to cause lung infection, the full scope and impact of this Legionella secretion system is still relatively underappreciated. By utilizing an expanded proteomic approach and testing newly made mutants in a wide range of assays, we have determined that the L. pneumophila type II secretome encompasses approximately 120 proteins, and among these proteins is a novel polysaccharide deacetylase (PdaA) that modulates the L. pneumophila surface and lipopolysaccharide, impacting intracellular infection, biofilm formation, and resistance to both antibiotics and human serum. Moreover, since T2SSs and homologs of PdaA were found in many other bacteria, our findings should also have implications for understanding other infectious diseases and environmental processes.

RevDate: 2025-06-24

Jordana-Lluch E, Escobar-Salom M, Torrens G, et al (2025)

Corticosteroids modulate biofilm formation and virulence of Pseudomonas aeruginosa.

Biofilm, 9:100289.

Corticosteroids are anti-inflammatory drugs commonly administered to patients with chronic obstructive pulmonary disease (COPD), cystic fibrosis and similar lung pathologies, in which persistent infections with Pseudomonas aeruginosa are frequent. However, their therapeutic value is debatable because of their adverse impact on host immunity. The aim of this work was to determine the impact of budesonide and fluticasone propionate on P. aeruginosa biology. We found that these corticosteroids attenuated its intrinsic pro-inflammatory properties (reduction of IL-8 release compared to controls ca. 15 % (budesonide) and 50 % (fluticasone propionate)) and cellular invasiveness (25 % and 40 % respectively). Corticosteroids enhanced P. aeruginosa biofilm formation in a time/dose-dependent manner (around 1.6-fold for the highest concentration, with this increase occurring more readily in sputum media)) and stimulated the release of extracellular DNA (2-fold increase), a key component of the biofilm matrix. Regarding the mechanisms involved, our results suggest that corticosteroids diffuse through P. aeruginosa's membrane influencing its fluidity and triggering cell envelope stress signalling pathways, as shown by an initial increase in mucA (σ[22] regulon) expression, outer membrane vesicle release and accumulation of cyclic diguanylate (c-di-GMP). Changes in the levels of this intracellular signalling molecule, responsible for the switch from planktonic to biofilm lifestyle, may explain some of the phenotypes observed. In conclusion, our data, first obtained with type strains and proved to be reproducible when using COPD clinical isolates, suggest that corticosteroids could mediate a faster acquisition of the phenotypic characteristics associated with P. aeruginosa long-term adaptation to the chronic lung niche without undergoing mutation.

RevDate: 2025-06-20

Sun S, Xin Q, Ma Z, et al (2025)

Self-Assembled Photothermal Particles Boost Synergistic Biofilm Eradication and Remineralization in Early Dental Caries Treatment.

Small (Weinheim an der Bergstrasse, Germany) [Epub ahead of print].

Dental caries, driven by dietary habits and microbial biofilms, remains a significant global health issue. In situ biomimetic remineralization is considered a promising method, but its low efficiency is a key challenge. Additionally, the interference of cariogenic bacteria further exacerbates the problem. In this study, self-assembled photothermal particles (PAEB) with light-boosted synergistic biofilm eradication and remineralization properties for caries treatment are reported. Composed by polyaspartic acid-stabilized amorphous calcium phosphate (Pasp-ACP) and ε-poly-L-lysine/baicalein (EPL-BC), PAEB enable efficient light-to-heat conversion under near-infrared light exposure due to polymerization and stacking of baicalein. The localized hyperthermia, accompanied with EPL-BC disrupts bacterial membranes and eradicates biofilm by more than 99%, which is seven times higher than the non-radiation group (12.86%) and ≈21 times higher than the fluoride group (4.35%). Meanwhile, the releasing of calcium and phosphate ions is accelerated for rapid remineralization, with highest hardness recovery (1.96 GPa) of all groups, comparable to untreated healthy enamel. Moreover, in vivo microbiome analysis confirms that PAEB selectively reduces the abundance of cariogenic Streptococcus spp. while maintaining overall microbial diversity and oral ecological balance, presenting a promising solution for non-invasive dental caries treatment. This photothermal-enhanced strategy gives a reference for the design of bioactive therapeutic dental materials.

RevDate: 2025-06-20

Zhao X, He G, Liu B, et al (2025)

The Influence of SDM on the Performance of the EGSB-Two-Stage A/O Biofilm Process for Pig Wastewater Treatment and Mechanism Investigation.

Water environment research : a research publication of the Water Environment Federation, 97(6):e70127.

To address the treatment of pig wastewater containing high levels of organic matter, this study investigated the impact of sulfadimethoxine (SDM) on the performance and underlying mechanisms of an expanded granular sludge bed (EGSB) combined with a two-stage anoxic/oxic (A/O) biofilm process. The reactor demonstrated robust organic loading tolerance (up to 12,195 mg/L COD) while maintaining stable treatment performance, achieving > 95% COD removal efficiency and 70%-80% ammonia nitrogen (NH3-N) elimination. Systematic analysis of sludge microstructure and microbial consortia was conducted through integrated techniques, including scanning electron microscopy (SEM) and high-throughput sequencing. The introduction of SDM induced significant restructuring of microbial architecture and population dynamics, with Proteobacteria (21.73%-89.74%), Firmicutes (5.54%-33.53%), Chloroflexi (1.22%-23.07%), Bacteroidetes (2.48%-12.23%), and Synergistetes (15.64%-26.86%) emerging as dominant phyla. Notably, Proteobacteria and Firmicutes demonstrated superior resistance under the reaction process. Concurrently, microbial analysis revealed a significant enrichment of nitrogen-phosphorus-removing genera Acinetobacter and Pseudomonas during the reaction process, establishing that these bacterial taxa play a central role in the biodegradation of organic pollutants. Therefore, the microorganisms exhibited adaptability to high-load antibiotic-containing environments, substantiating the hybrid reactor's potential for livestock and poultry breeding wastewater treatment. SUMMARY: The presence of antibiotics reduces the removal of conventional pollutants by the combined process. Antibiotics cause changes in microbial population structure. EGSB-two-stage A/O combination process can effectively treat high organic load wastewater.

RevDate: 2025-06-19

Li CH, Chao WH, Wu PC, et al (2025)

Remote biofilm dislodgment using focused acoustic vortex.

Ultrasonics sonochemistry pii:S1350-4177(25)00202-0 [Epub ahead of print].

Biofilms constitute a major challenge in treating implant-associated and chronic infections due to their structural resilience and drug resistance, particularly as implant demand rises due to aging populations. Conventional methods are often invasive, complex, and costly, while focused ultrasound (FUS) poses risks related to biocompatibility and tissue damage. Distinguished by its helical phase structure and rotational energy distribution, focused acoustic vortex (FAV) theoretically generates stronger rotational forces and acoustic streaming than FUS under identical acoustic conditions. This study investigates the feasibility of FAV technique for biofilm removal. Biofilms in vitro model were established using Escherichia coli, and a 2-MHz custom-built ultrasound transducer was employed to generate either FAV or FUS. Results indicated that FAV activation generated a centripetal vortical flow with rapid rotation, which was adjustable via acoustic pressure and duty cycle. Conversely, FUS generated solely outward acoustic streaming, exhibiting a flow velocity 43.6 % lower than that of FAV. At 1.75 MPa, implementing a 10 % duty cycle and a 180 s treatment, FAV removed 97 % of the biofilm, whereas FUS removed only 7 %. To achieve a comparable removal rate (95.8 %), FUS required 4 MPa for 10 minutes. Streaming velocity (R[2] = 0.99) exhibited a strong correlation with biofilm removal, while inertial cavitation (R[2] = 0.19) exhibited a weak correlation; thus, the former was identified as the primary contributing mechanism. Importantly, FAV treatment resulted in minimal thermal elevation (<5 °C) and no significant reduction in cell viability, demonstrating its biosafety under the applied acoustic parameters. Synergistic tests with antibiotics further suppressed biofilm regrowth for up to 72 h, reducing bacterial concentration by 91 %. Future work will focus on in vivo biofilm models and assessing the safety and efficacy of combined treatments to advance clinical applications.

RevDate: 2025-06-20

Alshehri T, Alkhalifah I, Alotaibi A, et al (2025)

The impact of Caralluma munbyana extracts on Streptococcus mutans biofilm formation.

Frontiers in dental medicine, 6:1575161.

BACKGROUND/OBJECTIVES: Caralluma plants have a wide range of anti-inflammatory and antimicrobial activities. This study aims to assess the antibacterial effect of water, methanol, and ethanol extracts of Caralluma munbyana against Streptococcus mutans biofilms.

METHODS: Three extracts of C. munbyana were prepared using water, methanol, and ethanol. Multiple concentrations ranging between 2.93 and 93.75 mg/ml were achieved, alongside a control group with no extract, and incubated with an overnight culture of S. mutans. In the following day, the total absorbance was measured at 595 nm. Then, the biofilms were fixed and stained with 0.5% crystal violet to measure the biofilm absorbance at 490 nm. One-way ANOVA and Tukey's post-hoc tests were applied to identify which specific concentrations differed from the control.

RESULTS: C. munbyana methanol and ethanol extracts significantly affected the total absorbance of S. mutans (P ≤ 0.001) at 46.87 and 93.75 mg/ml. For biofilm inhibition, C. munbyana water extract was effective (P ≤ 0.001) in reducing the biofilm growth at 23.44 (1.34 ± 0.08), 46.87 (1.31 ± 0.15), and 93.75 (1.04 ± 0.07) mg/ml when compared to the control (1.58 ± 0.11). More reduction was observed among methanol and ethanol extracts, as C. munbyana methanol extract significantly (P ≤ 0.001) inhibited the S. mutans biofilm growth at 23.44 (0.99 ± 0.15), 46.87 (0.12 ± 0.02), and 93.75 (0.09 ± 0.01) mg/ml. Similarly, C. munbyana ethanol extract's biofilm inhibition was observed at the concentrations of 23.44 (0.45 ± 0.12), 46.87 (0.10 ± 0.02), and 93.75 (0.09 ± 0.04) mg/ml.

CONCLUSION: These findings suggest that C. munbyana possesses antibacterial properties against S. mutans biofilms, particularly through its methanol and ethanol extracts.

RevDate: 2025-06-19

Abdelrazek HM, Ghozlan HA, Sabry SA, et al (2025)

Retraction notice to "Copper oxide nanoparticles (CuO-NPs) as a key player in the production of oil-based paint against biofilm and other activities" [Heliyon 10 (2024) e29758].

Heliyon, 11(9):e43267 pii:S2405-8440(25)01650-0.

[This retracts the article DOI: 10.1016/j.heliyon.2024.e29758.].

RevDate: 2025-06-21
CmpDate: 2025-06-18

Dias-Souza MV, Haq IU, Pagnin S, et al (2025)

Liposome-encapsulated antibiotics and biosurfactants: an effective strategy to boost biofilm eradication in cooling towers.

Microbial cell factories, 24(1):135.

An excessive amount of water is needed for cooling towers in oil refineries to cool the machinery. However, water has been observed to favor microbial growth and biofilms significantly. The microbial biofilms are usually treated with synthetic biocides, which are ineffective and generate toxic by-products harmful to the environment. This study explores using rhamnolipid and free or encapsulated antimicrobials in liposomes to control several bacterial species exhibiting low antimicrobial susceptibility in planktonic and biofilm forms. The antimicrobial efficacy of rhamnolipid was evaluated through minimum inhibitory concentration (MIC) tests, showing values between 0.244 and 31.25 µg/mL. Biofilm inhibition assays revealed that rhamnolipid significantly reduced biofilm viability, performing comparably to meropenem and more effectively than chloramphenicol. Liposomes were produced with initial diameters of 100 and 200 nm, and encapsulation efficiencies were 56.7% for rhamnolipid, 47.3% for meropenem, and 31.25% for chloramphenicol. Among the formulations, 100 nm rhamnolipid-loaded liposomes exhibited the highest antibiofilm efficacy, achieving up to 92% biofilm reduction in Stenotrophomonas maltophilia 94 (p < 0.01). Meropenem liposomes of 100 nm also performed better than their 200 nm counterparts, with up to 85% reduction in Pseudomonas aeruginosa biofilms (p < 0.05). No significant size-dependent differences were observed for chloramphenicol liposomes, with maximum inhibition around 60% at both sizes. Long-term stability and antibiofilm activity were evaluated exclusively for S. maltophilia 94 over 90 days of refrigerated storage (4 °C). Dynamic light scattering revealed significant vesicle size increases over time for both formulations (p < 0.05), yet their antibiofilm activity remained stable. Rhamnolipid liposomes (100 nm) maintained significantly higher efficacy than 200 nm vesicles throughout the period (p < 0.01). Meropenem liposomes retained considerable activity, though a moderate decrease was noted after 60 days. Scanning electron microscopy (SEM) at days 0 and 90 confirmed the antimicrobial impact of liposomal treatments: biofilms showed disrupted architecture, reduced extracellular matrix, and evident morphological damage to bacterial cells, supporting quantitative results. These findings demonstrate that liposome-encapsulated rhamnolipids and antibiotics are effective against resilient biofilms. The successful formulation and long-term stability of rhamnolipid liposomes highlight their potential as a sustainable and eco-friendly alternative for industrial biofilm control, reducing reliance on conventional biocides and minimizing environmental impact.

RevDate: 2025-06-20
CmpDate: 2025-06-18

Romero M, Luckett J, Dubern JF, et al (2025)

Combinatorial discovery of microtopographical landscapes that resist biofilm formation through quorum sensing mediated autolubrication.

Nature communications, 16(1):5295.

Bio-instructive materials that intrinsically inhibit biofilm formation have significant anti-biofouling potential in industrial and healthcare settings. Since bacterial surface attachment is sensitive to surface topography, we experimentally surveyed 2176 combinatorially generated shapes embossed into polymers using an unbiased screen. This identified microtopographies that, in vitro, reduce colonization by pathogens associated with medical device-related infections by up to 15-fold compared to a flat polymer surface. Machine learning provided design rules, based on generalisable descriptors, for predicting biofilm-resistant microtopographies. On tracking single bacterial cells we observed that the motile behaviour of Pseudomonas aeruginosa is markedly different on anti-attachment microtopographies compared with pro-attachment or flat surfaces. Inactivation of Rhl-dependent quorum sensing in P. aeruginosa through deletion of rhlI or rhlR restored biofilm formation on the anti-attachment topographies due to the loss of rhamnolipid biosurfactant production. Exogenous provision of N-butanoyl-homoserine lactone to the rhlI mutant inhibited biofilm formation, as did genetic complementation of the rhlI, rhlR or rhlA mutants. These data are consistent with confinement-induced anti-adhesive rhamnolipid biosurfactant 'autolubrication'. In a murine foreign body infection model, anti-attachment topographies are refractory to P. aeruginosa colonization. Our findings highlight the potential of simple topographical patterning of implanted medical devices for preventing biofilm associated infections.

RevDate: 2025-06-18

Kim IH, Shin JH, Jeong SB, et al (2025)

Compact and Cost-Effective Autofluorescence Sensor for Real-time Environmental Biofilm Monitoring.

Environmental research pii:S0013-9351(25)01422-7 [Epub ahead of print].

Biofilms, microbial communities embedded in extracellular polymeric substances (EPS), exhibit strong resistance to antimicrobial agents and physical cleaning, making their removal challenging. As persistent sources of contamination, biofilms pose significant challenges in industrial, medical, and environmental sectors. This study presents the development of compact, cost-effective sensor module for real-time biofilm monitoring under ambient light conditions. Using Staphylococcus epidermidis as a model biofilm, autofluorescence properties were analyzed, identifying 285 nm as the optimal excitation wavelength. Five sensor modules were evaluated for sensitivity, linearity, and cost efficiency, leading to the selection of the most suitable photodetector. A prototype was constructed by integrating a 285 nm LED, a photodetector, and a lock-in amplifier (LIA) to minimize environmental light interference. The compact sensor module (90 × 90 × 32 mm) demonstrated stable fluorescence detection under ambient light levels up to 200 lux. This study advances biofilm detection beyond laboratory-based methods, enabling real-time monitoring and management in industrial and everyday environments.

RevDate: 2025-06-18

Tang Y, Chen H, Deng J, et al (2025)

Flagellin deficiency drives multi-drug resistance in Salmonella through biofilm adaptation and efflux pump activation.

Veterinary microbiology, 307:110607 pii:S0378-1135(25)00242-1 [Epub ahead of print].

Salmonella remains a leading foodborne pathogen of global public health concern. Of particular clinical relevance is the monophasic variant of S. Typhimurium, serotyped as S. 4,[5],12:i:-, which has emerged as an increasingly prevalent multi-drug resistance (MDR) strain worldwide. Characterized by the absence of phase 2 flagellar antigen expression, this variant has drawn significant attention due to its association with antimicrobial resistance. In this study, we systematically investigated the impact of flagellin deficiency on antibiotic tolerance in S. Typhimurium and S. Choleraesuis through the construction of isogenic mutants rSC0196 (S. Typhimurium UK-1(ΔfljBΔfliC)) and rSC0199 (S. Choleraesuis C78-3(ΔfljBΔfliC)). Our findings reveal that flagellin gene deletion confers enhanced antibiotic resistance in both serovars, despite significantly impairing their biofilm-forming capacity. Intriguingly, while biofilm biomass was reduced in the mutants, the residual biofilms displayed markedly increased antibiotic tolerance. Further studies demonstrated that flagellin deficiency significantly upregulated efflux pump activity in both mutant strains. These findings provide compelling evidence that flagellin deletion may serve as a key driver of MDR in S. 4,[5],12:i:- clinical isolates, potentially through dual mechanisms involving biofilm phenotypic alterations and efflux pump potentiation. This work not only advances our fundamental understanding of flagellin function in Salmonella pathogenesis but also provides valuable insights for the development of novel antimicrobial strategies targeting flagellin-mediated pathways.

RevDate: 2025-06-18

Anandraj FN, Panda TK, Thangarasu S, et al (2025)

Persulfate salts to combat bacterial resistance in the environment through antibiotic degradation and biofilm disruption.

Water research, 284:123941 pii:S0043-1354(25)00849-8 [Epub ahead of print].

Antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs) have become a critical topic among researchers because of the excessive use of antibiotics in human and animal health care. Globally, it poses a serious threat to human health and the environment. Antibiotics are often poorly metabolized, with 30-90 % excreted into the environment, contaminating aquatic and ground ecosystems, and fostering resistance. Advanced oxidation processes (AOPs), particularly sulfate radical-based AOPs (SR-AOPs), offer promising solutions for degrading antibiotics and resistant biofilms. Persulfate (PS) and Peroxymonosulfate (PMS) are key oxidants in these processes, generating sulfate and hydroxyl radicals when activated by heat, UV light, or transition metals. PS with a redox potential of E°=2.01 V is an affordable and effective oxidant. However, PS requires activation for the degradation of contaminants. PMS is stable across a broad pH range and produces both sulfate and hydroxyl radicals, allowing it to function independently without activation. Thus, PMS serving as a versatile agent for environmental treatment. This review broadly describes the degradation mechanisms of different classes of antibiotics and biofilms. Despite these promising developments, SR-AOPs still face challenges in managing complex wastewater systems, which often contain multiple pollutants. Moreover, gaps remain in understanding of the toxicity of reaction intermediates and in optimizing the large-scale application of these processes. Future research should focus on the in-situ generation of sulfate radicals, combining different activation methods to enhance degradation efficiency, and developing sustainable and cost-effective approaches for large-scale wastewater treatment.

RevDate: 2025-06-20
CmpDate: 2025-06-18

Wang F, Chen S, Zhou J, et al (2025)

ARTP mutagenesis for genome-wide identification of genes important for biofilm regulation in spoilage bacterium Pseudomonas fluorescens PF08.

Applied and environmental microbiology, 91(6):e0021825.

Pseudomonas fluorescens is a vital food spoilage bacterium and commonly spoils foods in the form of biofilms. Yet its biofilm regulation strategies have not been fully revealed. Here, we conducted a genome-wide screen of genes important for biofilm regulation using atmospheric and room temperature plasma mutagenesis together with the whole-genome resequencing technology. Three genes (D7M10_RS02105, D7M10_RS27690, and D7M10_RS25705) encoding GGDEF-EAL domain-containing proteins were found to have different mutation manifestations between biofilm cells and free cells. On direct testing, null mutants of D7M10_RS02105 and especially D7M10_RS27690 exhibited significantly elevated cyclic di-GMP (c-di-GMP) levels. Further studies indicated that a higher level of c-di-GMP caused by the null mutant of D7M10_RS27690 triggered cell growth, the production of siderophore and exopolysaccharide as well as autoaggregation, and hindered cell motility, all of which together promote biofilm formation. RNA-sequencing analysis revealed the transcription profile regulated by D7M10_RS27690, mostly including flagellar assembly and peptidoglycan biosynthesis pathways. Therein, the downregulated genes enriched in flagellar assembly were verified by qRT-PCR; the result of which was in agreement with the decreased cell motility.IMPORTANCEBiofilms formed by spoilage bacterium Pseudomonas fluorescens will bring about food quality and safety issues. In this study, we present the establishment of a genetic method and verified its reliability and efficiency for identifying genes associated with biofilm regulation. The genes we discovered offer new perspectives on the mechanisms of biofilm regulation in spoilage bacterium P. fluorescens. Moreover, the gene screen method based on atmospheric and room temperature plasma mutagenesis and whole-genome resequencing-coupled technology overcomes the labor-intensive issues caused by traditional methods and should generally be suitable for identifying genes associated with biofilm formation or dispersion in other bacteria.

RevDate: 2025-06-18

Yang G, Yang R, Zhu X, et al (2025)

In vitro and in vivo activity of sodium houttuyfonate and sodium new houttuyfonate against Candida auris infection by affecting adhesion, aggregation, and biofilm formation abilities.

Microbiology spectrum [Epub ahead of print].

UNLABELLED: Candida auris is a rapidly spreading multidrug-resistant fungus that causes fatal infections under certain global conditions. Sodium houttuyfonate (SH) and sodium new houttuyfonate (SNH) are stable derivatives of houttuynin (decyl aldehyde) extracted from Houttuynia cordata, both possessing antifungal and antibacterial pharmacological activities. However, the inhibitory effects of SH and SNH on C. auris remain unclear. Therefore, this study aims to evaluate the potential activity and possible mechanisms of SH and SNH as antifungal agents against C. auris. First, our results showed that SH and SNH exhibit significantly inhibitory activity against fluconazole-resistant C. auris strains, but do not possess effective fungicidal activity. In addition, transcriptome and RT-qPCR studies revealed that SH and SNH can repress the expression of genes related to adhesion, aggregation, and biofilm formation. Next, we observed that SH and SNH can disrupt the adhesion and aggregation of early-stage C. auris. Furthermore, using the XTT assay, crystal violet staining, and confocal laser scanning microscopy, we found that the biofilm formation ability of C. auris was disrupted by SH and SNH. We also found that SH and SNH can potentially increase chitin content and expose β-1,3-glucan in the cell wall. Finally, infection models using Galleria mellonella larvae and mice with systemic candidiasis demonstrated that SH and SNH significantly inhibited the colonization and pathological damage of C. auris in vivo. Therefore, our presented results suggest that SH and SNH can effectively inhibit the growth, adhesion, aggregation, and biofilm formation to treat its colonization and pathological damage to the host of C. auris.

IMPORTANCE: Recently, the annual proportion of non-C. albicans infections has been rising. The most notable characteristic of C. auris is its resistance to drugs, including multidrug resistance, which results in treatment failures and poses significant challenges in controlling its spread. Sodium houttuyfonate (SH) and sodium new houttuyfonate (SNH) are effective and stable derivatives of houttuynin (decyl aldehyde) extracted from traditional Chinese herbal medicine Houttuynia cordata, both possessing antifungal and antibacterial pharmacological activities. However, the inhibitory effects of SH and SNH on C. auris remain unclear. Through in vitro and in vivo approaches, we have demonstrated that SH and SNH can effectively inhibit the growth, adhesion, aggregation, and biofilm formation to treat its colonization and pathological damage to the host of C. auris. Thus, our findings provide new insights into possible options for clinical applications in the anti-C. auris.

RevDate: 2025-06-18

Kurbatfinski N, Jurscisek JA, Wilbanks KQ, et al (2025)

Respiratory tract antimicrobial peptides more effectively killed multiple methicillin-resistant Staphylococcus aureus and nontypeable Haemophilus influenzae isolates after disruption from biofilm residence.

Microbiology spectrum [Epub ahead of print].

UNLABELLED: Bacteria newly released (NRel) from biofilm residence via multiple methodologies are commonly significantly more sensitive to antibiotics. We've induced NRel with this phenotype after incubation of biofilms formed by diverse human pathogens with an epitope-targeted monoclonal antibody directed at protective domains within bacterial DNABII proteins that provide structural support to the eDNA-dependent biofilm matrix. The observed heightened sensitivity was due, in part, to increased NRel membrane permeability. In three animal models of human biofilm-mediated infections, this monoclonal induced biofilm disruption with rapid concomitant bacterial clearance and disease resolution in the absence of any co-delivered antibiotic, which suggested a key role of innate immune effectors. Recently, we showed that NRel of the respiratory pathogen nontypeable Haemophilus influenzae (NTHI), as mediated by the DNABII-directed monoclonal, are also highly vulnerable to killing by human polymorphonuclear neutrophils (PMNs). Here, we extended these observations to show that the transient, yet highly vulnerable anti-DNABII NRel phenotype of three isolates of both NTHI and methicillin-resistant Staphylococcus aureus (MRSA) included significant sensitivity to killing by three antimicrobial peptides commonly expressed within the respiratory tract or by PMNs (e.g., human β-defensins 1 and 3 as well as the cathelicidin, LL-37). We envision induction of the NRel phenotype by delivery of this monoclonal antibody to patients with recalcitrant biofilm-mediated diseases to provide greatly improved medical management. Ideally, clearance of NRel will be mediated by innate immune effectors of an immunocompetent host or, if needed, by co-delivered traditional antibiotics, which are canonically ineffective against biofilm-resident bacteria but would be highly effective against NRel.

IMPORTANCE: Pathogenesis of most common chronic and/or recurrent bacterial diseases (e.g., middle ear infections, urinary tract infections, rhinosinusitis, among others) can be attributed to biofilms that are canonically highly resistant to both immune effectors and antibiotics. If we treat biofilms formed by diverse human pathogens with a targeted monoclonal antibody directed at protective domains of bacterial DNA-binding proteins integral to the structural stability of the eDNA-rich biofilm matrix, they are rapidly disrupted with concomitant release of the resident bacteria. These newly released (NRel) bacteria are transiently significantly more sensitive to killing by both traditional antibiotics and human PMNs, and herein, we showed that they are also more readily killed by antimicrobial peptides. Clinically, we hope to leverage this understanding of the NRel phenotype for better medical management of these challenging infections, as well as perhaps even limit or eliminate further contribution to the global antimicrobial resistance 'pandemic'.

RevDate: 2025-06-18

Wan Ahmad Kamil WN, Zainal M, Mokhtar M, et al (2025)

Aggregation and biofilm formation of mono- and co-culture Candida species and Staphylococcus aureus are affected by nutrients in growth media.

Biofouling [Epub ahead of print].

Candida species and Staphylococcus aureus coexist in nosocomial infections. These interkingdom interactions are associated with oral biofilm formation, leading to various oral diseases. This study elucidated the interkingdom interactions of these microorganisms, particularly their aggregation and biofilm formation, in three different media. Candida auris, Candida albicans, Candida lusitaniae, Candida dubliniensis, Candida parapsilosis, Candida glabrata and S. aureus were used in this study. Aggregation assays were conducted to determine planktonic interaction, and biofilm assays were performed to investigate intra- and interkingdom interactions in a static biofilm environment. Most Candida spp. exhibited a high auto-aggregation percentage in brain heart infusion broth supplemented with yeast extract (BHIYE). In addition, co-culture biofilm with S. aureus significantly reduced the total cell counts of Candida spp. compared to mono-culture (p < 0.05). In conclusion, co-aggregation, biofilm biomass and total cell count were species- and growth medium-dependent, and S. aureus interacted antagonistically with Candida spp.

RevDate: 2025-06-17

Yang J, Zhang L, Sun H, et al (2025)

Synergistic membrane-biofilm-sludge system coupling partial nitritation and anammox: achieving efficient nitrogen removal in high-ammonia/low-carbon condensate wastewater.

Bioresource technology pii:S0960-8524(25)00785-0 [Epub ahead of print].

Condensed wastewater treatment faces challenges from elevated ammonia-nitrogen levels (1972-2365 mg/L), a low carbon-to-nitrogen ratio (0.02-0.03), and inhibitory sulfides. To overcome these, a novel hybrid system integrating an effluent membrane-enhanced fixed-biofilm activated sludge (IFAS) reactor with partial nitritation/anammox (PN/A) was developed. The system demonstrated exceptional nitrogen removal performance at a maximum nitrogen removal rate of 1.5 kg N/(m[3]·d) with a nitrogen removal efficiency of 82.3 %. Denitrification enhanced advanced nitrogen removal with a low nitrate production ratio (4.5 %), minimizing secondary pollution risks. Microbial analysis revealed substantial enrichment of anaerobic ammonium-oxidizing bacteria, with Candidatus Brocadia dominating the biofilm community (24.3 %). Membrane-mediated biomass retention selectively enriched Nitrosomonas (10.1 %) in suspended sludge, while biofilm detachment promoted granular anammox biomass development and further elevated Candidatus Brocadia abundance by 4.8 %. This synergistic configuration enhances process stability for treating high-ammonia/low-carbon wastewater and promotes the practical implementation of IFAS-PN/A systems.

RevDate: 2025-06-17

Pan Y, Liu H, Liu Y, et al (2025)

Antimicrobial peptide-antibiotic synergy exerts anti-streptococcus suis infection by membrane disruption, ROS induction and biofilm inhibition.

International immunopharmacology, 161:115053 pii:S1567-5769(25)01043-4 [Epub ahead of print].

With the increasing emergence of antimicrobial resistance, the rise of multidrug-resistant Streptococcus suis (S. suis) has caused a great threat on global public health. The combination of antimicrobial peptide (AMP) and antibiotics is an efficient strategy to enhance antibacterial efficacy and combat bacterial antibiotic resistance. In this study, the antibacterial efficacy of chicken-derived AMP CATH-1 combined with tetracycline against S. suis infection was investigated in vitro and in vivo. The results showed that combination of CATH-1 and tetracycline exerted effectively anti-S. suis activity, which rapidly killed all tested bacteria in 60 min. In the mice infection model, CATH-1 combined with tetracycline improved survival rate of SC19-infected mice, reduced bacterial load in different tissues and alleviated the inflammatory response as well as inflammatory damage. Furthermore, CATH-1 reduced the emergence of bacterial resistance to tetracycline. Mechanically, CATH-1 disrupted cell membrane via SEM observation and SYTO9/PI staining. CATH-1 in combination with tetracycline aggravated reactive oxygen species (ROS) accumulation and proton motive force (PMF) disruption compared to CATH-1 or tetracycline alone. In addition, CATH-1 inhibited efflux pump function. Importantly, we identified a critical gene steAB associated with biofilm formation and CATH-1 alone or in combination with tetracycline inhibited biofilm formation. Our study shows effective anti-S. suis infection of CATH-1-tetracycline synergy, which provides the basis on the development of AMP as additives to antibiotics.

RevDate: 2025-06-17
CmpDate: 2025-06-17

Wang Y, Sun C, Cai L, et al (2025)

Osmotic and pH Stress-Responsive Two-Component System, OmpR/EnvZ, Modulates Type III Secretion, Biofilm Formation, Swimming Motility and Virulence in Acidovorax citrulli xjL12.

Molecular plant pathology, 26(6):e70107.

Acidovorax citrulli, the causal pathogen of bacterial fruit blotch of cucurbits, relies on a functional type III secretion system (T3SS) for pathogenicity. Two-component systems (TCSs) are primary signal transduction mechanisms for bacteria to detect and adapt to various environmental conditions. However, the role of TCS on regulating T3SS and other virulence factors in response to environmental stimuli is still poorly understood in A. citrulli. Here, we report the identification of a conserved TCS, OmpR/EnvZ, involved in hypersensitive response (HR) induction in Nicotiana benthamiana by screening a transposon-insertion library in the group II strain xjL12 of A. citrulli. Transcription analysis confirmed that OmpRAc/EnvZAc was upregulated in response to elevated osmotic pressure, low and high pH conditions, and host environment. Deletions of envZAc, ompRAc, or both envZAc and ompRAc in A. citrulli attenuated virulence to melon seedlings and mature leaf tissues, and delayed HR in N. benthamiana. OmpRAc was activated by EnvZAc and directly bound to the promoter region of hrpG, a major regulator of T3SS. This binding activated hrpG transcription and promoted T3SS assembly in T3SS-inducing medium, XVM2. Additionally, the OmpRAc/EnvZAc mutants of A. citrulli displayed reduced swimming motility due to impaired flagella formation, but also had enhanced biofilm formation and exopolysaccharide production. OmpRAc/EnvZAc regulation of these virulence factors in A. citrulli depended on its own conserved phosphorylation sites. This work illuminates a signalling pathway for regulating the T3SS and provides insights into the OmpR/EnvZ-mediated virulence regulatory network in A. citrulli.

RevDate: 2025-06-16

Yang Y, Chen N, Fan J, et al (2025)

Spatiotemporal Immunomodulation of Macrophages via NLRP3/IL-1β Pathway by Core-Shell Microneedles to Promote Healing of Biofilm-Infected Diabetic Ulcers.

Small (Weinheim an der Bergstrasse, Germany) [Epub ahead of print].

Macrophage phenotypic dysregulation, spatially by biofilm and dynamically in time, impedes the healing of diabetic ulcers (DUs). Effective treatment requires enabling spatiotemporal regulation of macrophage polarization, balancing the M1 pro-inflammatory antimicrobial response with the M2 anti-inflammatory tissue-regeneration response. Here, a core-shell microneedle system (LM-MG@MN) is proposed with spatiotemporal immunomodulation features, designed to spatially disrupt biofilm barriers and sequentially induce macrophage polarization from M0 to M1 and subsequently to M2 by regulating the NLRP3/IL-1β pathway. Glucose oxidase (GOX)-loaded 2D MXene nanosheets (MG) are encapsulated in a hyaluronic acid-β-cyclodextrin (HA-β-CD) matrix as the MN shell layer. The rapid dissolution of this shell triggers MG to induce pro-inflammatory polarization of macrophages from M0 to M1, aiding in clearing biofilm infections. Liposomes (LM) carrying the NLRP3 inflammasome inhibitor MCC950 are embedded within a methacrylate hyaluronic acid (HAMA) matrix in the MN core. In the later stages of wound healing, LM is released gradually from the core, promoting the anti-inflammatory polarization of macrophages from M1 to M2 and accelerating tissue regeneration by enhancing crosstalk with fibroblasts and endothelial cells. Additionally, RNA sequencing indicates that LM-MG@MN regulates macrophage metabolic reprogramming to enhance DUs healing. This spatiotemporal immunomodulation strategy offers a promising approach for clinical DUs treatment.

RevDate: 2025-06-16

Crippa BL, Valente PLM, Barros ELP, et al (2025)

Investigation of biofilm-associated genes and biofilm formation in Non-aureus Staphylococcus (NAS) isolated from cow's milk.

Biofouling [Epub ahead of print].

The isolation of non-aureus Staphylococcus (NAS) from the milk of both healthy cows and cows with mastitis has been frequently reported. However, there are few in-depth studies regarding their virulence profile and the ability of these microorganisms to form biofilms. Therefore, this research aimed to evaluate the biofilm formation capacity of NAS isolates from Brazilian milk. In this work, 309 NAS isolates were subjected to the Congo Red Agar (CRA) phenotypic test. Next, genotypic characterization was carried out by screening the bap, icaA, icaD, and MSCRAMMs genes: bbp, cna, ebps, eno, fib, fnbA, fnbB, clfA and clfB. Finally, ten isolates that presented the highest frequency of the genes analysed were selected to evaluate their ability to form biofilm on stainless-steel discs. t The number of cells (log10 CFU/cm[2]) in the biofilms was assessed at three time periods (24 h, 48 h, and 72 h) at a temperature of 25 °C. 35 NAS (11.32%) produced biofilms in the CRA test. Genotypic analysis showed the eno (38.5%) and bap (27.5%) genes were the most prevalent. In the analysis of biofilm formation on stainless steel, the factor 'growth time' had no significant effect on cell numbers. All selected isolates formed biofilm on stainless steel, and cell numbers were estimated to be in the 5.94 to 9.10 log10 CFU/m[2] range. These results provide evidence that NAS isolated from milk may represent a risk to human and animal health since they carry several virulence genes and demonstrate the ability to form biofilms.

RevDate: 2025-06-17

Tareau AS, Tahrioui A, Gonzalez M, et al (2025)

Squalamine and claramine A1 disperse Pseudomonas aeruginosa biofilm.

Biofilm, 9:100293.

Pseudomonas aeruginosa is an opportunistic pathogen that causes both acute and chronic infections, including pneumonia, bloodstream infections, urinary tract infections, and surgical site infections. It poses a significant threat to individuals with chronic lung conditions, particularly those with cystic fibrosis. Squalamine and claramine A1 have emerged as promising antibacterial compounds, exhibiting activity against a broad range of both Gram-positive and Gram-negative bacteria. Beyond their potent antibacterial properties, our findings reveal that sub-inhibitory concentrations of claramine A1 and squalamine can disperse pre-formed P. aeruginosa biofilm without impacting bacterial growth. While claramine A1, but not squalamine, enhances membrane fluidity, the structural difference between these compounds lies primarily in their spermine and spermidine moieties. Notably, we found that spermine, unlike spermidine, was able to both disperse biofilm and increase membrane fluidity. Together, our results suggest that while both compounds are effective at disrupting P. aeruginosa biofilm, they likely act through distinct mechanisms.

RevDate: 2025-06-17

Kuik C, de Boer C, van Hoogstraten SWG, et al (2025)

Proteomic signatures of Staphylococcus aureus biofilm maturation on orthopaedic implants.

Biofilm, 9:100287.

Implant-associated infections pose a significant clinical challenge in the orthopaedic field, often leading to implant failure and revision surgeries. These infections are hard to treat, particularly due to the formation of bacterial biofilms. Orthopaedic implant surfaces feature varying roughness and compositions to optimise implant osseointegration and performance. Highly polished surfaces are used in articulating areas of high shear force to minimise wear particle formation, while rough or porous surfaces enhance implant and bone fixation. However, increased surface roughness or porosity can also promote bacterial adhesion and biofilm formation, potentially elevating the risk of chronic infections. In this study, an automated single-pot solid-phase enhanced sample preparation protocol (SP3) workflow was developed to investigate the differences in proteomic response of immature and mature S. aureus biofilms on titanium (Ti) surfaces with varying roughness (polished, corundum-blasted), and a plasma-sprayed microporous calcium phosphate coated surface (plasmapore), representing clinically relevant orthopaedic implants. Mature biofilms showed increased proteins related to toxin activity and the tricarboxylic acid (TCA) cycle, while immature biofilms had elevated proteins tied to binding, catalytic activities, and metabolism, suggesting surface topography influences early biofilm formation. This study highlights potential protein targets for novel antimicrobial therapies and suggests testing these as coatings on Ti surfaces, with the proteomics platform serving as a tool to evaluate bacterial and host responses.

RevDate: 2025-06-15

Souza CM, Paulo EA, Souza NAA, et al (2025)

Enhanced biofilm formation by Candida tropicalis morphotypes under host-mimicking conditions: Insights into cell wall modifications and gene expression.

Microbial pathogenesis pii:S0882-4010(25)00532-7 [Epub ahead of print].

BACKGROUND AND OBJECTIVE: Candida tropicalis is an important fungal pathogen capable of colonizing diverse host niches. This study investigates how phenotypic switching influences biofilm formation by C. tropicalis under host-mimicking conditions, including simulative vaginal secretions (VS) and artificial urine (AU).

METHODS: Our study analyzed three morphotypes derived from the 49.07 switching system: a clinical strain (parental) and two phenotypic switching morphotypes, rough variant and rough revertant (RR). Biofilm formation on polystyrene was assessed under different culture conditions (AU, VS, and RPMI-1640). Biofilm characteristics, including filamentation, cell surface hydrophobicity, and cell wall composition (β-glucan, chitin, and mannan), were investigated. Additionally, the expression levels of Agglutinin-like sequence genes (CtrALS1, CtrALS3) and the EFG1 gene (Enhanced filamentous growth protein 1) was quantified using RT-qPCR.

RESULTS: Phenotypic switching morphotypes of C. tropicalis produced significantly more biofilm under host-like conditions compared to the parental strain. Increased filamentation in the rough variant and revertant correlated with biofilm biomass across all conditions. Switched morphotypes also exhibited higher cell surface hydrophobicity and altered cell wall composition, with increased β-glucan and variable chitin content under host-mimicking conditions. The RR morphotype showed higher expression of CtrALS3 and EFG1 compared to the parental strain in AU and VS.

CONCLUSIONS: Phenotypic switching influences important biofilm traits-hydrophobicity, filamentation, cell wall composition, and gene expression-in host-mimicking environments. These findings highlight the role of phenotypic switching in C. tropicalis adaptation to host niches, particularly vaginal fluids and urine.

RevDate: 2025-06-17
CmpDate: 2025-06-14

Lehmusvaara S, Sillanpää A, Wouters M, et al (2025)

M.marinum lacking epsH shows increased biofilm formation in vitro and boosted antibiotic tolerance in zebrafish.

NPJ biofilms and microbiomes, 11(1):109.

Recent discoveries have indicated that biofilm communities may play a role in natural drug tolerance of Mycobacterium tuberculosis. A transposon-based mutation library of a closely related species, Mycobacterium marinum, was used to identify clones in which the relative amount of extracellular DNA (eDNA), an important component of the extracellular matrix of biofilms, is altered. The disruption of a putative glycosyl transferase gene QDR78 11175, epsH, caused a substantial increase of the eDNA content of biofilms, and increased the growth rate and the biomass/cell in biofilm-forming conditions compared to wild-type. The increased abundance of biomass was mainly due to the elevated levels of eDNA and proteins in the extracellular matrix. The growth of the ΔepsH strain in the zebrafish was normal, but the mutant developed greater antibiotic tolerance in the adult zebrafish model. These results suggest that the extracellular matrix of biofilms increases antibiotic tolerance of mycobacteria during infection.

RevDate: 2025-06-14

Ju X, Sun H, Ruan C, et al (2025)

Prophage induction and quorum sensing enhance biofilm stability and resistance under ammonia-oxidizing bacteria-mediated oxidative stress.

Water research, 284:124010 pii:S0043-1354(25)00918-2 [Epub ahead of print].

Ammonia-oxidizing bacteria (AOB) and prophage-carrying bacteria are prevalent in water treatment and reuse systems, yet their interactions and implications for biofilm formation and microbial risks remain insufficiently understood. Here, we demonstrate that oxidative stress arising from the metabolism of the AOB Nitrosomonas europaea induces prophage activation in lysogenized Escherichia coli (λ+). This activation triggers cellular lysis, leading to the release of intracellular components (e.g., protein and DNA) and upregulated quorum sensing (QS) followed by biosynthesis and excretion of extracellular polymeric substance (EPS). Integrated transcriptomic and proteomic analysis revealed that the presence of N. europaea significantly upregulated QS- and EPS-related genes by 2.14-2.93 and 2.81-3.11 folds in E. coli (λ+), respectively. Surviving E. coli (λ+) exhibited enhanced prophage-bacterium symbiosis and activated toxin-antitoxin systems, enhancing their resilience to environmental stress. These microbial adaptations markedly increased EPS production, fostering biofilm development and conferring enhanced biofilm resilience to disinfectants and bacterial antibiotic tolerance. Furthermore, metagenomic analysis at the microbial community wide level demonstrated that ammonia addition-driven AOB enrichment stimulated multi-species biofilm formation, promoted bacterium-phage interactions, and increased bacterial antibiotic resistance. Overall, our findings reveal that oxidative stress driven by AOB accelerates biofilm development, an overlooked phenomenon with potential to exacerbate microbial risks.

RevDate: 2025-06-17
CmpDate: 2025-06-13

Kamwouo T, Bouttier S, Domenichini S, et al (2025)

Extracellular DNA filaments associated with surface polysaccharide II give Clostridioides difficile biofilm matrix a network-like structure.

NPJ biofilms and microbiomes, 11(1):108.

Clostridioides difficile is an anaerobic, spore-forming, Gram-positive bacterium, and a leading cause of healthcare-associated intestinal infections. Recurrences occur frequently, most of them being relapses. Apart from spores, C. difficile biofilm is hypothesized as a reservoir for relapses. Thus, increased knowledge on in vitro biofilm formation and characteristics is required. We finely characterized the matrix components in 4 C. difficile strains. Confocal microscopy revealed for the first time the presence of eDNA filaments connecting bacteria, with a spider's web-like organization. Biofilm disruption with DNase I suggests that eDNA, even in low abundance, plays a key role in the biofilm scaffold, maintaining biofilm cohesion by connecting bacteria. Observation of strong overlapping staining, particularly in the highest biofilm-producing strain tested between eDNA and polysaccharide II or lipoprotein CD1687, suggests that interactions between these components may enhance biofilm cohesion. Whereas autolysis does not appear to be a major way of matrix component release under our conditions, eDNA was sometimes associated with lipidic round shapes that can evoke vesicle structures. Together, these results suggest that the bacterial aggregation and structuring of the C. difficile biofilm involve several components of the matrix, including eDNA, interacting with each other to build the scaffold of biofilm.

RevDate: 2025-06-13

P AT, Jayakumar J, Vinod V, et al (2025)

Anti-Biofilm Activity of Lysostaphin-Functionalized Titanium Surfaces Against Staphylococcus aureus.

Microbial pathogenesis pii:S0882-4010(25)00525-X [Epub ahead of print].

Staphylococcus aureus has the ability to adhere to implant surfaces and form biofilms, which are highly resistant to standard antimicrobial treatments. These biofilm infections pose significant risks, particularly for patients with medical implants. This study investigates the covalent attachment of lysostaphin (Lst) to titanium (Ti) surface (Lst-Ti) and it's antibiofilm activities. Lst-Ti surfaces were characterized using energy-dispersive X-ray spectroscopy (SEM-EDS) confirming successful protein attachment. Biocompatibility was assessed through cell viability tests, revealing minimal hemolytic activity and excellent cytocompatibility. Antimicrobial assays demonstrated that Lst-Ti inhibited S. aureus growth and disrupted established biofilms, including those formed by methicillin-resistant S. aureus (MRSA). Scanning electron microscopy further validated the reduction in biofilm formation on the modified surfaces. These results suggest that Lst-Ti surfaces offer a promising strategy for preventing and treating implant-associated biofilm infections. Unlike antibiotic-loaded surfaces, Lst-Ti provides long-term antimicrobial protection without any release Lst protein, reducing the risk of antibiotic resistance and systemic absorption. This approach could enhance patient outcomes by reducing the need for implant removal in infection cases. Future in vivo studies will be necessary to confirm the clinical applicability of this approach.

RevDate: 2025-06-13

Zhang Y, Lin Y, Zhang J, et al (2025)

Diversity of optrA Genetic Structures in Enterococcus faecalis from Retail Chicken and the Differential Biofilm-Forming Abilities of Isolates at Non-Frozen Temperatures.

Journal of applied microbiology pii:8161686 [Epub ahead of print].

AIMS: This study aimed to explore the diversity of optrA genetic structures in Enterococcus faecalis from retail chicken and the variance in their biofilm-forming capabilities at refrigerated and room temperatures. By comprehensively studying these two traits, we aim to fully understand the transmission and biofilm-forming capabilities at non-frozen temperatures of optrA-positive E. faecalis.

METHODS AND RESULTS: Analysis of Chinese-sourced E. faecalis genomes in the database indicated that 65.76% were optrA-positive, with animals as the predominant hosts. In 2020, 15 optrA-carrying strains were isolated from 96 retail chicken samples from four Chinese supermarkets. The optrA gene was situated on plasmids or chromosomes. A novel optrA-carrying plasmid structure was identified, resulting from IS1485-mediated structural changes. Tn6674-like and Tn558-like structures mediated inter-chromosomal transfer of optrA, while IS1216E and ISEnfa1 promoted inter-plasmid transfer. Some isolates showed a greater tendency for biofilm formation at refrigerated temperature, and others at room temperature.

CONCLUSIONS: In conclusion, this research reveals the genetic intricacy of optrA-positive E. faecalis and their temperature-associated biofilm-forming behaviors, highlighting the necessity of monitoring food-related microbial hazards.

RevDate: 2025-06-15

Yilmaz Topcam MM, Prayoonwiwat N, Bruschi C, et al (2025)

Exogenous L-Cysteine and Its Transport Through CtaP Play a Role in Biofilm Formation, Swimming Motility, and Swarming Motility of Listeria monocytogenes.

Foods (Basel, Switzerland), 14(11):.

Listeria monocytogenes is of a significant concern for the food industry, largely due to its ability to form biofilms. Flagellar motility and environmental factors are crucial for biofilm formation. Cysteine is an important compound affecting the behavior of this bacterium; therefore, we investigated its role in growth, biofilm formation and motility of L. monocytogenes 10403S through a mutant in cysteine uptake (ΔctaP). Basal defined media (DM) and L-cysteine-supplemented DM were used. Biofilm formation was promoted by L-cysteine supplementation in both wild type (WT) and ΔctaP. Lower biofilm formation of ΔctaP compared to WT indicates the significance of the cysteine transporter and cysteine uptake. A negative correlation was found between growth and biofilm formation, especially in the presence of high L-cysteine concentrations. Motility experiments showed that as the L-cysteine concentration increased, the swarming motility of WT decreased. Furthermore, swimming motility of WT was enhanced with L-cysteine supplementation, while the swimming motility of ΔctaP remained unaffected. To evaluate the role of cysteine and CtaP in biofilm formation and motility, transcriptome analysis, comparing WT and ΔctaP in basal and L-cysteine-supplemented (1.57 and 3.67 mM) DM, was conducted at 37 °C. The investigation of biofilm-related genes explained the role of ctaP and revealed induced expression of flagella and chemotaxis genes by L-cysteine.

RevDate: 2025-06-15

Florit-Ruiz A, Rago L, Rojas A, et al (2025)

Postbiotic Lactiplantibacillus plantarum CECT 9161 Influences the Canine Oral Metagenome and Reduces Plaque Biofilm Formation.

Animals : an open access journal from MDPI, 15(11):.

Periodontal diseases are highly prevalent in dogs and intricately interconnected with the composition and functional attributes of the oral microbiota. The demand for non-invasive interventions to support oral health presents an opportunity for functional ingredients. The novel postbiotic heat-treated (HT) Lactiplantibacillus plantarum CECT 9161 inhibited growth and biofilm formation of oral microorganisms in vitro. The in vitro growth of saliva-derived biofilms was also inhibited and revealed microbiome modulation. Two doses of the postbiotic (LOW: 5 mg dog/day, HIGH: 25 mg/dog/day) were assessed in a placebo-controlled, double-blinded, 57-day clinical trial involving 60 dogs. Associations were found between the postbiotic, reduced plaque formation, and modulation of the oral microbiome, including increased abundance of genes involved in denitrification, heme and catechol biosynthesis, and oxidative stress reduction. The results suggest that HT Lactiplantibacillus plantarum CECT 9161 may support oral health in dogs by modifying the microbiome of supragingival plaque and reducing plaque formation.

RevDate: 2025-06-15
CmpDate: 2025-06-13

Lin LC, Tsai YC, NT Lin (2025)

Phage-Antibiotic Synergy Enhances Biofilm Eradication and Survival in a Zebrafish Model of Pseudomonas aeruginosa Infection.

International journal of molecular sciences, 26(11):.

Pseudomonas aeruginosa is a gram-negative opportunistic pathogen that poses a significant threat due to its increasing multidrug resistance, particularly in clinical settings. This study aimed to isolate and characterize a novel bacteriophage, phiLCL12, from hospital wastewater and evaluate its potential in combination with antibiotics to combat P. aeruginosa infections and biofilm formation. Transmission electron microscopy revealed that phiLCL12 possesses a long contractile tail. The isolated phage exhibited a broad host range of 82.22% and could adsorb up to 98% of its target within 4 min. It was effective against multidrug-resistant strains at both high and low multiplicities of infection (MOIs) levels in lysis tests. Taxonomic classification was determined using PhaGCN2 and Whole genomic analysis, and the results identified phiLCL12 as a member of the Pbunavirus. In vitro experiments demonstrated that phiLCL12 significantly enhanced biofilm clearance and inhibited biofilm formation when combined with sub-inhibitory concentrations of imipenem. Furthermore, in vivo experiments using a zebrafish model showed that phage-antibiotic synergy (PAS) improved survival rate compared to antibiotic treatment alone. This study demonstrates that phiLCL12 is effective in both eradicating and preventing P. aeruginosa biofilm formation. The combination of phiLCL12 and imipenem provides a synergistic effect, significantly enhancing survival outcomes in a zebrafish model. These findings highlight the potential of phage-antibiotic synergy as a promising therapeutic strategy against biofilm-associated infections.

RevDate: 2025-06-15
CmpDate: 2025-06-13

Górecka H, Guźniczak M, Buzalewicz I, et al (2025)

Alpha-Mangostin: A Review of Current Research on Its Potential as a Novel Antimicrobial and Anti-Biofilm Agent.

International journal of molecular sciences, 26(11):.

Alpha-mangostin (α-MG) is a prenylated xanthone extracted from the pericarp of the mangosteen tree (Garcinia mangostana) fruit. The compound exhibits a broad range of therapeutic properties, such as anti-inflammatory, antioxidative, and antimicrobial activity. This review highlights new findings in antibacterial studies involving α-MG, demonstrates its potent activity against Gram-positive bacteria, including Staphylococcus and Enterococcus genera, and describes the antibacterial mechanisms involved. Most cited literature comes from 2020 to 2025, highlighting the topic's relevance despite limited new publications in this period. The primary antibacterial mechanism of α-MG consists of the disruption of the bacterial membrane and increased bacterial wall permeability, leading to drug accumulation and cell lysis. Other mechanisms include genomic interference and enzyme activity inhibition, which impair metabolic pathways. α-MG can also disrupt biofilm formation, facilitate its removal, and prevent its maturation. Furthermore, α-MG presents strong synergistic action with common antibiotics and other phytochemicals, even against drug-resistant strains, facilitating infection treatment and allowing for reduced drug dosage. The main challenge in developing α-MG-based drugs is their low aqueous solubility; therefore, nanoformulations have been explored to improve its bioavailability and antibacterial stability. Extended research in this direction may enable the development of effective antibacterial and anti-biofilm therapies based on α-MG.

RevDate: 2025-06-12

Ruan Y, Li R, Zheng P, et al (2025)

AD1 Aptamer-Engineered Fluconazole-Loaded PLGA-PEG Nanoformulations Potentiate Antifungal Efficacy through Biofilm-Penetrating Targeting against Candida albicans.

ACS applied bio materials [Epub ahead of print].

In this work, aptamer AD1-modified poly(lactic-co-glycolic acid)-poly(ethylene glycol)-fluconazole nanoparticles (AD1-PLGA-PEG-FLUCZ) were prepared, enabling the antifungal drug FLUCZ to specifically target the biofilm of Candida albicans, prolonging its action time on the biofilm, and enhancing its killing effect. The analytical results demonstrated that the AD1-PLGA-PEG-FLUCZ nanoparticulate system achieved a FLUCZ loading capacity of 5.89 ± 0.07% with an encapsulation efficiency of 84.51 ± 0.18%. Physicochemical characterization revealed a uniform particle size distribution (390 nm) and stable surface charge (-30.45 mV). Furthermore, the formulation exhibited minimal hemolytic activity and low cytotoxicity in biocompatibility assessments. AD1-PLGA-PEG-FLUCZ adheres to the cell surface of C. albicans, causing severe cellular damage and collapse, prolonging its lag phase and shortening the logarithmic growth phase. AD1-PLGA-PEG-FLUCZ demonstrates significant inhibitory effects on C. albicans biofilms, with this inhibitory activity being concentration-dependent. AD1-PLGA-PEG-FLUCZ-treated mice infected with C. albicans biofilms demonstrated accelerated body weight recovery and near-normalization of the serum Mouse C-Reactive Protein levels. Concurrently, comparatively lower serum concentrations of ALT and AST were observed in the AD1-PLGA-PEG-FLUCZ treatment group, indicating minimized hepatocellular injury. H&E staining results revealed no detectable damage in the heart, liver, spleen, lung, and kidney tissues of mice treated with AD1-PLGA-PEG-FLUCZ. Furthermore, while C. albicans infection induced significant pulmonary pathology, the treated group exhibited near-complete restoration of lung tissue histology. Analysis using an in vivo imaging system in mice demonstrated that AD1-PLGA-PEG-FLUCZ exhibited significant accumulation in both the hip-infected area and lung tissue, indicating its pronounced targeting effect against C. albicans. In conclusion, AD1-PLGA-PEG-FLUCZ exhibits a targeted anti-C. albicans effect and holds promise as an agent for combating C. albicans.

RevDate: 2025-06-12

ElKenawy RH, Zaki MES, Essa SG, et al (2025)

Molecular study of candiduria in pediatric patients in in relation to biofilm formation and fluconazole tolerance.

Diagnostic microbiology and infectious disease, 113(2):116943 pii:S0732-8893(25)00266-4 [Epub ahead of print].

BACKGROUND: There are limited studies about the presence of Candida species (Candida spp.) and ABC genotypes in hospital acquired urinary tract infection (UTI) in children.

AIM: the study aimed at identification of Candida spp. associated with candiduria in children, detection of fluconazole tolerance and biofilm formation and genotyping of C. albicans.

METHOD: The study was conducted on pediatric patients with hospital-acquired UTI. A urine sample was cultured on the agar CHROM Candida. Molecular identification of Candida spp. was performed by nested polymerase chain reaction (PCR) and specific genotyping of C. albicans was performed by PCR. Biofilm production and fluconazole tolerance were tested for the isolates.

RESULTS: 97 children were included. Urinary catheters were inserted reported in 69.1 % of the children and previous antibiotic intake was reported in 34 % of them. The identified species were C. albicans (66 %) followed by Nakaseomyces glabrata (19.6 %), Candida tropicalis (11.3 %) and Candida kruzei (3.1 %). The ability of biofilm formation was 100 %. The Pichia kudriavzevii had a highest significant rate of fluconazole tolerance (66.7%), (P=0.045). Resistance to fluconazole was observed significantly with C. tropicalis (63.6%), (P=0.033). The common genotypes of C. albicans were A (60.9%) and C (39.1%). There was significant capacity of C. albicans genotype C to form strong biofilm (P<0.001).

CONCLUSION: The study found that C. albicans remains the most prevalent species in candiduria. The ability of Candida spp. to form biofilms was 100% among the isolates. Strong biofilm formation being significantly associated with increased fluconazole resistance and C. albicans genotype C.

RevDate: 2025-06-12

Zhao L, Zhang H, Zha L, et al (2025)

Bactericidal and anti-biofilm activity of ebastine against Staphylococcus aureus.

Letters in applied microbiology pii:8161046 [Epub ahead of print].

Drug repurposing, offers promising opportunities to address infections caused by multidrug-resistant bacteria. This study was to evaluate the bactericidal activity, anti-biofilm properties, and potential mechanisms of the antihistamine drug ebastine against S. aureus. The minimum inhibitory concentrations of ebastine against standard and clinical S. aureus isolates were determined using the broth microdilution method. The MIC values ranged from 2 to 8 µg·mL-1, indicating good activity against clinical drug-resistant strains. Time-kill curve analyses revealed a dose-dependent bactericidal effect. Regarding anti-biofilm activity, ebastine significantly inhibited biofilm formation at higher concentrations and demonstrated a moderate ability to eradicate preformed biofilms. Mechanistic studies revealed that ebastine exerted the antimicrobial effects by causing disruption to bacterial membrane integrity and inducing reactive oxygen species generation. Furthermore, safety evaluations showed that ebastine exhibited limited toxicity to mammalian cells, with negligible hemolytic effects and good overall safety profiles. This study provided new insights into the potential applications of ebastine in the field of antimicrobial therapy, highlighting its promise as a non-traditional antibacterial agent.

RevDate: 2025-06-13

Badge AK, Sharma I, Bankar NJ, et al (2025)

Integration of three-dimensional multicolor holography with microfluidic three-dimensional biofilm-on-a-chip technology for advancing the treatment of diabetic foot ulcers: An innovation in phage therapy.

Journal of research in medical sciences : the official journal of Isfahan University of Medical Sciences, 30:27.

RevDate: 2025-06-12

Matela AM, Siatkowski CW, Yan C, et al (2025)

Student-led experimental evolution reveals novel biofilm regulatory networks underlying adaptations to multiple niches.

bioRxiv : the preprint server for biology pii:2025.06.06.658356.

UNLABELLED: We established a research-education partnership known as EvolvingSTEM that provides secondary school students the opportunity to conduct authentic research experiments centered on microbial evolution. These experiments are currently conducted by thousands of high school students and can offer an unprecedented window into biofilm adaptation while building a community of young researchers. Providing high school students access to research experiences improves learning and can have positive and long-lasting impacts on their attitudes towards science. Moreover, student research can make impactful scientific contributions. Through EvolvingSTEM, students evolve populations of Pseudomonas fluorescens in a biofilm bead model and observe heritable changes in colony morphology. Genome sequencing of 70 mutants that they picked identified parallel mutations in genes known to regulate biofilm growth (wsp , yfiBNR , morA, fuzY). We also uncovered novel adaptations: loss-of-function mutations in phosphodiesterase PFLU0185 that did not alter colony morphology, and mutations affecting periplasmic disulfide bond formation producing small colonies. PFLU0185 mutations consistently reached high frequencies and phenotyping revealed roles in cyclic di-GMP regulation, biofilm formation, and motility, prompting us to name this gene bmo (b iofilm and mo tility o ptimizer). Competition experiments and microscopy demonstrated bmo mutants employ generalist strategies and coexist with the ancestor and specialist mutants through niche differentiation. Consequently, phenotypic diversity is maintained, with smooth (ancestral and bmo) colonies consistently outnumbering wrinkly and fuzzy variants. The study advances understanding of biofilm genetic architecture while demonstrating that student-led research can uncover mechanisms of microbial adaptation relevant to Pseudomonas infection biology and provide transformative STEM experiences.

IMPORTANCE: Bacterial biofilms dominate microbial life, yet their evolutionary genetics remain incompletely understood. This science education project engages thousands of high school students in experimental evolution, yielding discoveries about biofilm adaptation while transforming their science education. Selected mutants included PFLU0185/ bmo , a conserved phosphodiesterase that helps bacteria balance the competing demands of attachment and dispersal essential for biofilm life cycle success. The finding that smooth-colony generalists rather than conspicuous variants dominate biofilm adaptation adds to our understanding of the process of niche differentiation in biofilms. This work also demonstrates the power of distributed research networks for discovery of new genetic pathways of adaptation. Students gained authentic research experience, potentially inspiring them to join the next generation of scientists, while identifying mutants adapted to discrete conditions that maintain diversity within biofilms. This synergy between education and discovery offers a scalable model for addressing complex biological questions while developing scientific literacy in diverse classrooms.

RevDate: 2025-06-12

Sarkar S, Barnaby R, Nymon A, et al (2025)

Let-7b-5p loaded Mesenchymal Stromal Cell Extracellular Vesicles reduce Pseudomonas - biofilm formation and inflammation in CF Bronchial Epithelial Cells.

bioRxiv : the preprint server for biology pii:2025.05.28.656674.

UNLABELLED: Cystic Fibrosis (CF) is a multiorgan disease caused by mutations in the CFTR gene, leading to chronic pulmonary infections and hyperinflammation. Among pathogens colonizing the CF lung, Pseudomonas aeruginosa is predominant, infecting over 50% of adults with CF, and becoming antibiotic-resistant over time. Current therapies for CF, while providing tremendous benefits, fail to eliminate persistent bacterial infections, chronic inflammation, and irreversible lung damage, necessitating novel therapeutic strategies. Our group engineered mesenchymal stromal cell derived extracellular vesicles (MSC EVs) to carry the microRNA let-7b-5p as a dual anti-infective and anti-inflammatory treatment. MSC EVs are low-immunogenicity platforms with innate antimicrobial and immunomodulatory properties, while let-7b-5p reduces biofilm formation and inflammation. In a preclinical CF mice model, we reported that let-7b-5p-loaded MSC EVs reduced P. aeruginosa burden, immune cells, and proinflammatory cytokines in the lungs. We hypothesize four complementary mechanisms for the observed in-vivo effects of the let-7b-5p loaded MSC EVs: antimicrobial activity, anti-inflammatory properties, inhibition of antibiotic-resistant P. aeruginosa biofilm formation in CF airways, and stimulation of anti-inflammatory macrophage behaviors. This study focused on the second and third mechanisms and demonstrates that MSC EVs engineered to contain let-7b-5p effectively blocked the formation of antibiotic-resistant P. aeruginosa biofilms on primary human bronchial epithelial cells (pHBECs) while also reducing P. aeruginosa -induced inflammation. This approach holds promise for improving outcomes for people with CF. Future work will focus on optimizing delivery strategies and expanding the clinical applicability of MSC EVs to target other CF-associated pathogens.

NEW AND NOTEWORTHY: This is the first study demonstrating that let-7b-5p loaded Mesenchymal Stromal Cell Extracellular Vesicles (MSC EVs) block antibiotic-resistant P. aeruginosa biofilm formation and reduce inflammation in CF primary human bronchial epithelial cells.

RevDate: 2025-06-12

Puerner C, Morelli KA, Kerkaert JD, et al (2025)

Transcriptional analysis of developing Aspergillus fumigatus biofilms reveals metabolic shifts required for biofilm maintenance.

bioRxiv : the preprint server for biology pii:2025.06.02.657448.

UNLABELLED: Aspergillus fumigatus is a filamentous fungus found in compost and soil that can cause invasive and/or chronic disease in a broad spectrum of individuals. Diagnosis and treatment of aspergillosis often occur during stages of infection when A. fumigatus has formed dense networks of hyphae within the lung. These dense hyphal networks are multicellular, encased in a layer of extracellular matrix, and have reduced susceptibility to contemporary antifungal drugs, characteristics which are defining features of a microbial biofilm. A mode of growth similar to these dense hyphal networks observed in vivo can be recapitulated in vitro using a static, submerged biofilm culture model. The mechanisms underlying filamentous fungal cell physiology at different stages of biofilm development remain to be defined. Here, we utilized an RNA sequencing approach to evaluate changes in transcript levels during A. fumigatus biofilm development. These analyses revealed an increase in transcripts associated with fermentation and a concomitant decrease in oxidative phosphorylation related transcripts. Further investigation revealed that ethanol and butanediol fermentation is important for mature biofilm biomass maintenance. Correspondingly, a gene (silG), a predicted transcription factor, was observed to also be required for mature biofilm biomass maintenance. Taken together, these data suggest temporal changes in A. fumigatus metabolism during biofilm development are required to maintain a fully mature biofilm.

IMPORTANCE: Aspergillus fumigatus is the most common etiological agent of a collection of diseases termed aspergillosis. Invasive P ulmonary A spergillosis (IPA), a severe form of aspergillosis, is highlighted by invasive growth of fungal hyphae into host lung tissue. Strains that are susceptible to antifungal therapies in vitro frequently fail to respond to treatment in vivo, resulting in high mortality rates even with treatment. It is now appreciated that this decreased antifungal efficacy in vivo is, in part, likely due to biofilm-like growth of the fungus. A. fumigatus biofilms have been shown to develop regions of limited oxygen availability that are hypothesized to induce cell quiescence and drug resistance. Understanding the mechanisms by which A. fumigatus induces, develops, and maintains biofilms to evade antifungal therapies is expected to illuminate biofilm-specific therapeutic targets. Here we present transcriptomics data of developing A. fumigatus biofilms and from these data define genes related to fungal fermentation and regulation of transcription important for maintenance of mature A. fumigatus biofilms.

RevDate: 2025-06-11

Thakur R, S Yadav (2025)

Exopolysaccharides and biofilm forming microbial inoculant AB-13 acting in a consortium promotes growth of economically important medicinal plant Catharanthus roseus.

International journal of biological macromolecules pii:S0141-8130(25)05675-2 [Epub ahead of print].

Biofilm and Exopolysaccharides (EPS) from bioinoculants have previously displayed industrial applications but their role as plant probiotics is underexplored. In this study, biofilm forming and exopolysaccharides producing microbe (AB-13) was isolated and molecular characterization was done along with plant growth promoting traits. Biofilm and EPS characterization was done by biophysical techniques like XRD, FTIR and SEM-EDAX which revealed amorphous nature, signature carbohydrate related peaks and surface morphology. Under natural conditions, pot experiments on Catharanthus roseus were conducted by supplementation of microbial consortium containing AB-13 and a previously reported AB-11 isolates. Multiple branching in shoots, roots and early flowering with delayed senescence over control plants were observed. The consortium efficiently boosted the growth of C. roseus plants with maximum shoot length of 42 ± 1.54 cm and root length of 17.05 ± 1.36 cm with an increase of 11 % and 18 % respectively as compared to control. In consortium inoculated plants, the maximum fresh weight (37.32 ± 1.78 g) and dry weight (5.77 ± 0.27 g) with an increase of fresh weight (41.55 %), dry weight (50.59 %) and total chlorophyll content (43.88 %) was recorded, as compared to control. Thus, we can conclude that the above microbial consortium promoted growth and development of economically important plant C. roseus.

RevDate: 2025-06-11

Chen H, Song C, Wang Q, et al (2025)

Advanced treatment of coal gasification wastewater using a multistage aerated biofilm reactor with hydrophilic polyurethane carriers.

Journal of environmental management, 389:126141 pii:S0301-4797(25)02117-6 [Epub ahead of print].

To address the challenges posed by the complexity and recalcitrance of coal gasification wastewater (CGW), this study developed a multistage aerated biofilm reactor incorporating hydrophilic polyurethane as the biofilm carrier for advanced treatment of CGW. The results demonstrated that the reactor exhibited excellent resistance to shock loads and effectively treated high concentrations of ammonia nitrogen (NH4[+]-N) and refractory organic compounds. At hydraulic retention times (HRTs) of 24 h, 12 h, and 8 h, the NH4[+]-N removal efficiency consistently exceeded 97 %, with complete conversion to nitrate. Notably, at an HRT of 12 h, the chemical oxygen demand (COD) removal efficiency reached a maximum of 42.68 ± 9.27 %. Further analyses using three-dimensional fluorescence spectroscopy and gas chromatography-mass spectrometry revealed high removal efficiencies of 75.66 %, 76.58 %, and 63.89 % for alkanes, phenolic compounds, and phthalate esters, respectively. The reactor's robust biofilm stability was confirmed by the high protein-to-polysaccharide ratio in extracellular polymeric substances (EPS) ranging from 3.35 to 5.85, with tightly bound EPS correlating significantly with biofilm stability. Microbial community analysis identified Nitrosomonas as the dominant ammonia-oxidizing bacteria (AOB), alongside Nitrospira and Candidatus_Nitrotoga as the key nitrite-oxidizing bacteria (NOB). Simultaneously, dominant genera including PLTA13, Fimbriimonadaceae, Blastocatellia 11-24, and Ahniella played key roles in degrading refractory organic compounds. These findings highlight the promising potential of the multistage aerated biofilm reactor for the efficient advanced treatment of CGW.

RevDate: 2025-06-11
CmpDate: 2025-06-11

Ramos LA, Walls EC, Petrucci MS, et al (2025)

Growth and Polarization of A549 Human Alveolar Epithelial Cells as a Model to Study Biofilm Formation in Acinetobacter baumannii.

Methods in molecular biology (Clifton, N.J.), 2942:35-44.

Acinetobacter baumannii is an opportunistic pathogen that has a propensity to cause infections in immunocompromised patients. With the increasing incidence of antibiotic-resistant isolates, Acinetobacter baumannii has emerged as one of the most problematic pathogens in recent decades with the World Health Organization urging prioritization for additional research focusing on this nosocomial pathogen. The following protocol outlines the process of culturing and polarizing A549 human alveolar epithelial cells for infection with Acinetobacter baumannii to study biofilm formation. The protocol additionally outlines the process of fixing the infected A549 cells for downstream applications.

RevDate: 2025-06-11

Anonymous (2025)

RETRACTION: Preparation and Optimization of Hydrophilic Modified Pullulan Encapsulated Tetracycline for Significant Antibacterial and Anti-Biofilm Activity Against Stenotrophomonas maltophilia Isolates.

Chemistry & biodiversity [Epub ahead of print].

RevDate: 2025-06-12

Buzisa Mbuku R, Poilvache H, Maigret L, et al (2025)

Targeting Staphylococcus aureus biofilm-related infections on implanted material with a novel dual-action thermosensitive hydrogel containing vancomycin and a tri-enzymatic cocktail: in vitro and in vivo studies.

Biofilm, 9:100288.

Implant-associated infections remain a critical challenge due to the presence of biofilm-forming bacteria, which enhance tolerance to conventional treatments. This study investigates the efficacy of a tri-enzymatic cocktail (TEC; DNA/RNA endonuclease, endo-14-β-d-glucanase, β-N-acetylhexosaminidase) targeting biofilm matrix components combined with supratherapeutic doses of antibiotics encapsulated in a thermosensitive hydrogel (poloxamer P407) for local administration. In vitro, the hydrogel formulation enabled controlled release of active agents over 12 h. Vancomycin and TEC co-formulated in hydrogel achieved up to 3.8 Log10 CFU count reduction and 80 % biofilm biomass reduction on MRSA biofilms grown on titanium coupons, demonstrating enhanced efficacy as compared to individual active agents, with 1.3-3.2 log10 additional killing. Fluoroquinolone efficacy remained unchanged by enzyme addition. In vivo, in a model of tissue cages containing titanium beads implanted in the back of guinea pigs, hydrogel-delivered vancomycin maintained therapeutic levels for seven days. Coupled with an intraperitoneal administration of vancomycin for 4 days, a single local administration of hydrogel containing both vancomycin and TEC was more effective than hydrogels containing either vancomycin or TEC, achieving an additional 2.1 Log10 CFU reduction compared to local vancomycin, 2.3 Log10 compared to local TEC, and 4.3 Log10 compared to systemic vancomycin treatment alone. However, partial regrowth occurred at later stages, indicating room for further optimization. Nevertheless, these findings already underscore the potential of combining a high dose of antibiotic with an enzymatic cocktail in a sustained-release hydrogel delivery system as a promising strategy for improving the management of biofilm-associated implant infections.

RevDate: 2025-06-10

Han Z, Zheng X, Zhao Z, et al (2025)

Revealing the characteristics and nitrogen metabolism mechanism of Anammox biofilm assisted by nanoscale zero-valent iron.

Journal of environmental management, 389:126137 pii:S0301-4797(25)02113-9 [Epub ahead of print].

Biofilm was an advanced approach to facilitating anaerobic ammonium oxidation (Anammox) application owing to high biomass retention and stable performance. The characteristics, nitrogen removal kinetics and microbial metabolic mechanism of Anammox biofilm with intermittent dosing of nanoscale zero-valent iron (nZVI) were comprehensively revealed. Anammox biofilm was acclimated efficiently with nZVI assistance within 110 days. nZVI stimulated the secretion of EPS, especially T-EPS and PN, which showed key importances in biofilm formation. The nitrogen removal kinetics were accurately described and predicted by the modified Boltzmann model. High-throughput sequencing revealed that the microbial richness and diversity gradually declined, while AnAOB were enriched from 0.12 % to 1.34 %. Furthermore, key functional genes involved in the Anammox pathway (e.g., hdh and hzsA/B/C) were enriched by 427.90-596.49 %. Anammox process was the dominant in the system, cooperating with other pathways driven by the Fe(II)/Fe(III) cycle. This study provided innovative insights into the enhanced mechanism of nZVI on Anammox.

RevDate: 2025-06-10

Lin C, Lin F, Wang J, et al (2025)

Mupirocin-Piperine Microemulsion Hydrogels Accelerate Healing of Infected Wounds through Deep Penetration and Biofilm Disruption.

Molecular pharmaceutics [Epub ahead of print].

The emergence of bacteria resistant to multiple first-line antibiotics has created an urgent demand for effective alternatives and a comprehensive approach to the healing of infected wounds. This study developed synergistic microemulsion hydrogels (Mup-Pip-ME-gels) combining piperine's biofilm-disrupting properties with mupirocin's antibacterial activity to combat antibiotic resistance and enhance wound healing. The optimization of the formulation was carried out using a pseudoternary phase diagram and response surface methodology, resulting in a microemulsion with stable physical properties: an average particle size of 57.54 nm and a zeta potential of -15.3 mV. This microemulsion was then incorporated into hydroxypropyl methylcellulose-based hydrogels for further investigation. The results demonstrated that the hydrogels exhibited excellent stability, minimal skin irritation, and significantly enhanced cumulative permeation compared with commercial products (Bactroban). Mup-Pip-ME-gels showed the largest inhibition zones against both Staphylococcus aureus and MRSA, measuring 46.0 ± 0.20 and 50.5 ± 0.50 mm, respectively, and achieved a significant biofilm disruption with inhibition rates of 85.0 ± 0.3% and 81.2 ± 0.7%. Pharmacodynamic studies indicated a 2.2-fold increase in the wound healing rate and a significant reduction in bacterial count (P < 0.01) by day 7. Overall, by combining natural compounds and antibiotics, Mup-Pip-ME-gels enhance transdermal permeation and wound healing while addressing antibiotic resistance, offering an effective topical treatment for bacterial infections.

RevDate: 2025-06-10

Sandim GC, Sardi JCO, da Silva ACB, et al (2025)

Exploring the Antimicrobial Potential of a Peptide Against Mixed Biofilm of Staphylococcus aureus and Candida albicans.

Probiotics and antimicrobial proteins [Epub ahead of print].

Candida albicans and Staphylococcus aureus species are, respectively, the most common fungal and bacterial agents isolated from bloodstream infections worldwide. In addition, 20% of all C. albicans bloodstream infections have been shown to be polymicrobial in nature, and the bacterium Staphylococcus aureus is the third most common co-isolated organism. Finding an efficient treatment strategy for polymicrobial infections is a major challenge, as traditional therapies most often target only individual agents within specific realms. Thus, the present study investigated the antimicrobial and anti-biofilm polymicrobial activity of the peptide ITR-16, a new synthetic peptide against microorganisms with a high incidence in nosocomial infections. This peptide was tested against S. aureus and C. albicans in planktonic form and mono and polymicrobial biofilm. Synergism assays with other common antimicrobials were performed. The ITR-16 peptide was also tested for its preliminary acute toxicity in an in vivo model of Galleria mellonella. The ITR-16 peptide showed antimicrobial activity, with minimal inhibitory concentrations (MICs) ranging from 0.62 to 2.5 µM. And treatment with ITR-16 at 10 × MIC significantly reduced biofilm formation and viability of S. aureus and C. albicans strains in both monospecies and polymicrobial biofilms. Furthermore, it demonstrated low toxicity in the G. mellonella model at anti-biofilm concentrations. These results present a new molecule with potential polymicrobial anti-biofilm activity.

RevDate: 2025-06-10

Wang L, Hou W, Wang H, et al (2025)

Nontargeted metabolomics analysis to unravel the anti-biofilm mechanism of Citrocin on Listeria monocytogenes.

Microbiology spectrum [Epub ahead of print].

Listeria monocytogenes biofilm formation is an important cause of cross-contamination in food processing. Citrinin is a potential broad-spectrum antimicrobial peptide. However, the effects of Citrocin on L. monocytogenes and its biofilm, as well as the associated mechanisms, remain to be explored. In this study, we evaluated the anti-biofilm effect of the antimicrobial peptide Citrocin on the foodborne pathogen L. monocytogenes and analyzed its anti-biofilm mechanism from the perspectives of swarming motility, extracellular polysaccharide production, and metabolite level changes. The results showed that Citrocin had a significant inhibitory effect on the growth of L. monocytogenes, with a minimum inhibitory concentration (MIC) of 0.075 mg/mL and a minimum bactericidal concentration (MBC) of 0.15 mg/mL. Citrocin at concentrations of MIC, 2 × MIC, and 4 × MIC could prevent biofilm formation and remove established biofilms. Metabolomics analysis revealed that Citrocin at 0.3 mg/mL caused a significant differential expression of metabolites in biofilms, up- and downregulating 23 and 13 metabolites, consisting mainly of amino acids, organic acids, and fatty acids, respectively. In addition, Citrocin significantly enriched energy and amino acid metabolic pathways, including alanine, glutamate, aspartate metabolism, TCA cycle, and arginine biosynthesis. This work provides potential biofilm regulation strategies and serves as a theoretical basis for the prevention and treatment of listeriosis.IMPORTANCEListeria monocytogenes biofilm formation is an important cause of cross-contamination during food processing. We found that Citrocin, an antimicrobial peptide that is widely used in animal feed, has good antimicrobial and anti-biofilm effects against L. monocytogenes. We preliminarily explored the anti-biofilm mechanism of Citrocin in terms of swarming motility, extracellular polysaccharide production, and metabolomics. Our work demonstrated that Citrocin is an excellent antimicrobial agent, which is important for the control of food cross-contamination and the preventive treatment of listeriosis.

RevDate: 2025-06-09

Behm AM, Yao H, Eze EC, et al (2025)

Inhibitors of the Bacterioferritin Ferredoxin Complex Dysregulate Iron Homeostasis and Kill Acinetobacter baumannii and Biofilm-Embedded Pseudomonas aeruginosa Cells.

ACS infectious diseases [Epub ahead of print].

In Pseudomonas aeruginosa, the iron storage protein bacterioferritin (Bfr) contributes to buffering cytosolic free iron concentrations by oxidizing Fe[2+] and storing the resultant Fe[3+] in its internal cavity, and by forming a complex with a cognate ferredoxin (Bfd) to reduce the stored Fe[3+] and mobilize Fe[2+] to the cytosol. Small molecule derivatives of 4-aminoisoindoline-1,3-dione designed to bind P. aeruginosa Bfr (Pa Bfr) at the Bfd binding site accumulate in the P. aeruginosa cell, block the Pa Bfr-Bfd complex, inhibit iron mobilization from Pa Bfr, elicit an iron starvation response, are bacteriostatic to planktonic cells, and are bactericidal to biofilm-entrenched cells. A structural alignment of Pa Bfr and Acinetobacter baumannii Bfr (Ab Bfr) showed strong conservation of the Bfd binding site on Ab Bfr. Accordingly, the small molecule inhibitors of the Pa Bfr-Bfd complex accumulate in the A. baumannii cells, elicit an iron starvation response, are bactericidal to planktonic cells, and exhibit synergy with existing antibiotics. These findings indicate that the inhibition of iron mobilization from Bfr may be an antimicrobial strategy applicable to other Gram-negative pathogens.

RevDate: 2025-06-09

Afify MGE, Gomaa OM, El Kareem HA, et al (2025)

Promoting bacterial colonization and biofilm formation for enhanced biodegradation of low-density polyethylene microplastics.

Bioresources and bioprocessing, 12(1):59.

The accumulation of plastic waste presents a significant worldwide environmental challenge. This study aimed to isolate polyethylene-degrading bacteria from marine samples containing plastic waste. Four culturable bacterial isolates: Micrococcus luteus, Bacillus cereus, Enterococcus faecalis, and Actinomyces sp. were assessed for their biofilm formation, biosurfactant, and protease production. Gamma irradiation was used to induce structural changes and promote bacterial colonization and biofilm formation on low-density polyethylene microplastics (LDPE MPs). Optimal biofilm formation was achieved in minimal media supplemented with 30% tryptic soy broth, 10% biosurfactant, and 300 µM calcium chloride. The factorial design experiment demonstrated that adding media supplementation significantly improved bacterial colonization and biofilm formation when compared to gamma irradiation. This was supported with Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX) mapping, and Fourier Transform Infrared Spectroscopy (FTIR). The optimized LDPE MP degradation was achieved through a multi-step protocol: (1) samples are pre-treated to 40 kGy gamma irradiation, which resulted in 5.7% Gravimetric weight loss and structural and morphological changes, (2) incubation in biofilm inducing media overnight, and (3) further incubation in minimal media for 30 days. This approach resulted in a total weight loss of 22.5%. In conclusion, synergistic pre-treatment is recommended to promote biofilm and improve biodegradation of LDPE MPs by marine bacteria.

RevDate: 2025-06-09

Danelon M, Nunes GP, Sterzenbach T, et al (2025)

Enhancing antimicrobial properties of glass ionomer cement through metallic agent reinforcement: A systematic review and meta-analysis: Alteration of the biofilm with metallic metal agents.

Journal of dentistry pii:S0300-5712(25)00336-7 [Epub ahead of print].

OBJECTIVES: This systematic review and meta-analysis (SRM) aimed to assess the impact of incorporating metallic agents into glass ionomer cement (GIC) and resin-modified glass ionomer cement (RMGIC) on their microbiological properties and antibacterial activity.

DATA SOURCES: Following PRISMA guidelines, the SRM included studies published up to August 21, 2024.

STUDY SELECTION: The eligibility criteria included clinical trials, in situ, and in vitro studies. The data were analyzed using RevMan software, and bias risk was assessed with the Joanna Briggs Institute's Checklist for in vitro studies and the ROBINS-I tool for clinical trials.

RESULTS: Out of 2,393 screened records, 32 studies were included. Results showed that metallic agents like silver, zinc oxide, titanium dioxide, and copper enhanced the antimicrobial properties of GIC and RMGIC. Most studies reported superior antimicrobial effects compared to controls, with only two studies showing neutral effects. Meta-analysis revealed that GIC with 5% TiO₂ or 2% ZnO nanoparticles significantly reduced S. mutans viability, while silver zeolite at 1% and 5% concentrations showed strong effects. Similarly, adding silver or ZnO to RMGIC improved its activity against S. mutans and L. acidophilus. The studies showed a low risk of bias.

CONCLUSIONS: Metallic agents enhance the antimicrobial efficacy of GIC/RMGIC, offering a promising solution for biofilm control in dental restorations. However, further research is needed to optimize their clinical application, particularly through in vivo studies, and to assess their impact on mechanical, esthetic, and cytotoxic properties.

CLINICAL RELEVANCE: Incorporating metallic agents into GIC and RMGIC enhances their antibacterial properties, improving biofilm control in dental restorations. This modification may reduce the risk of secondary caries and prolong restoration longevity.

RevDate: 2025-06-09
CmpDate: 2025-06-09

Lei B, Liu J, Zhao S, et al (2025)

Plaque disclosing agent as a plaque control guide for oral hygiene in chronic periodontitis based on guided biofilm therapy: A retrospective cohort study.

Medicine, 104(23):e42782.

We assessed the effectiveness of plaque disclosing agents as a visual aid for biofilm removal during professional oral hygiene instruction. A total of 220 patients with chronic periodontitis were enrolled in the study and divided into a control group (CG; traditional interventions) and an observation group (OG; guided biofilm therapy concepts applied). Plaque index (PI), bleeding on probing (BOP), and pocket depth (PD) were compared between the 2 groups. Self-care efficacy scale scores were assessed and compared, and oral hygiene behaviors were evaluated. After a 3-month intervention, the PI, BOP, and PD in OG reduced compared with those in CG. The total scores of the self-care efficacy scale in OG were higher than those in CG. The application of guided biofilm therapy concepts in the treatment and maintenance of patients with chronic periodontitis proves effective in reducing PI, BOP, and PD levels, enhancing patients' oral health management abilities, and ensuring sustained therapeutic outcomes.

RevDate: 2025-06-09
CmpDate: 2025-06-09

Lekhwar R, Kumar S, Tripathi M, et al (2025)

Novel therapeutic strategies targeting infections caused by P. aeruginosa biofilm.

Molecular biology reports, 52(1):571.

Pseudomonas aeruginosa is a gram-negative clinical pathogen, particularly affecting immunocompromised patients, those with cystic fibrosis, and burn victims. It causes chronic infections, especially in hospital settings, and is a significant contributor to nosocomial infections. Its capacity to create biofilms resistant to antibiotics is the reason for its infamous persistence in clinical settings. P. aeruginosa infections can affect any area of the body because the bacteria's biofilm enables it to stick to any surface, living or non-living. One of the primary clinical challenges in treating P. aeruginosa biofilm is its noteworthy resistance to many classes of antibiotics. The bacterium's ability to acquire resistance through efflux pumps, beta-lactamase production, and genetic mutations complicates treatment options. Recently, multidrug- resistant (MDR) strains of P. aeruginosa are becoming increasingly prevalent, limiting the efficacy of traditional antibiotics and leading to the need for alternative therapies. There is an ongoing need for novel treatment options, including bacteriophage therapy, antimicrobial peptides, and vaccines. The rapid adaptability of P. aeruginosa and its ability to develop resistance underscores the importance of continued research into new therapeutic strategies. This review discusses the various therapeutic strategies like; antimicrobial therapy, targeting efflux pumps and biofilms of P. aeruginosa, phage therapy, immunotherapy and nanotechnology to explore the mechanisms, through which antimicrobial compounds interact with biofilm structures and the bacteria within.

RevDate: 2025-06-09

Peremore C, van 't Hof C, Nkosi CL, et al (2025)

Biofilm characterisation of the maize rot-causing pathogen, Fusarium verticillioides.

Biofouling [Epub ahead of print].

Biofilm formation was investigated in a maize rot-causing pathogen, Fusarium verticillioides. This work revealed that in vitro cultures produce structured, adherent communities with a dense extracellular matrix (ECM) surrounding hyphae that makes up the biomass of a matured biofilm. Pellicle containing exopolysaccharide had a hydrodynamic diameter of 4.19 nm and a low viscosity (0.022 dl/g). The exopolysaccharide was composed of amino sugars and unordered, facilitating stability through complexation with the anionic eDNA. Biofilm formation varied over different pH and temperature values, emphasising its role in promoting adaption, survival, and persistence in F. verticillioides, potentially contributing to its pathogenicity in maize. Collectively, the results provide valuable insights into biofilm structure and stress resistance in this fungus, and will serve as a foundation for future studies incorporating in planta infection systems.

RevDate: 2025-06-09

Cattò C, Fassi EMA, Grazioso G, et al (2025)

Insights on Zosteric Acid Analogues Activity Against Candida albicans Biofilm Formation.

ACS omega, 10(21):22285-22295.

Zosteric acid (ZA), or p-(sulphooxy)-cinnamic acid, is a secondary metabolite of the seagrass Zostera marina able to reduce biofilm formation of a wide range of bacteria and fungi, through a nonbiocidal mode of action. However, the lack of information concerning the specific chemical structural elements responsible for ZA's antibiofilm activity has hindered the scaling up of this green-based technology for real applications. In this study, a small library of molecules based on ZA scaffold diversity was screened against the eukaryotic fungus Candida albicans, in order to identify the key chemical features of ZA necessary for inhibiting fungal biofilm at sublethal concentrations. Results, supported by multivariate statistical analysis, revealed that the presence of (i) the trans (E) double bond, (ii) the free carboxylic group in the side chain, and (iii) the para substitution with a hydroxyl group were all instrumental for maintaining the antibiofilm activity of the molecules. Additionally, molecular modeling studies suggested that the best performing derivatives interacted with NADP-(H) quinone oxidoreductase, influencing the microbial redox balance.

RevDate: 2025-06-09

Yuan X, Chao C, Niu J, et al (2025)

Mechanistic insights into nitrogen removal performance and electron competition with mixed electron donor supply in a biofilm electrode reactor.

Eco-Environment & Health, 4(2):100153.

In this study, a unique electrode configuration in the form of an "inverted T" was developed in the biofilm electrode reactor (BER), enabling superior nitrogen removal via the synergistic effect of hydrogen autotrophic denitrification and heterotrophic denitrification. In contrast to the sole heterotrophic denitrification in the biofilm reactor (BR), weak electric stimulation in the BER system promoted in situ hydrogen production as well as electron transport and utilization, resulting in a notable 20% improvement in NO 3 - removal efficiency for both influent COD/N ratios. Conversely, notable NO 2 - accumulation occurred under both COD/N ratios, with concentrations ranging from 6.0 to 8.0 mg/L. The enrichment of non-heterotrophic denitrifiers, such as Thermomonas, Pelomonas, and Hydrogenophaga, was observed in the BER with a relative abundance exceeding 1.0%, contributing to the hydrogen autotrophic denitrification pathway. Based on the outcomes of the multiple electron donor utilization in the coexistence of different electron acceptor combinations, despite H2 serving as an additional electron donor in the BER, electron competition was still detectable. Notably, nitrite reductase (Nir) emerged as the weakest competitor, resulting in a constrained NO 2 - reduction capacity. Based on the analysis of the electron competition characteristic, the potential NO 3 - metabolic pathway in the BER system was primarily driven by heterotrophic denitrification processes. The introduced electricity in the BER system was favorable for facilitating nitrogen removal through in situ production of hydrogen, direct supply of electrons from the electrode, improvement of functional microbial activity, and enhancement of enzymatic activity.

RevDate: 2025-06-08
CmpDate: 2025-06-08

García-Viñola V, Ezenarro J, Reguant C, et al (2025)

Interaction effects of fumaric acid, pH and ethanol on the growth of lactic and acetic acid bacteria in planktonic and biofilm states.

Food microbiology, 131:104808.

The microbial stability of wine can be compromised by the presence of lactic acid bacteria (LAB) and acetic acid bacteria (AAB), which can cause spoilage via off flavour production, increased acetic acid production, or biofilm formation. To manage the growth of LAB in winemaking, fumaric acid (FA) has been proposed as an alternative to traditional antimicrobial agents, such as sulfur dioxide (SO2). This study aimed to evaluate the inhibitory effects of FA on the growth of LAB and AAB based on the influence of pH and ethanol in a synthetic wine-like medium. The research involved the determination of the individual, 2 × 2 combined, and combined minimum inhibitory concentrations (MICs) of fumaric acid, pH, and ethanol. Specifically, the MIC90 was defined as the concentration required to inhibit the growth of more than 90 % of the initial population, and the MIC50 was defined as the concentration required to inhibit the growth of more than 50 % of the initial population. These thresholds were assessed in 19 bacterial strains (13 LAB and 6 AAB strains) at pH values of 3.5 and 4.0 and ethanol concentrations of 0, 4, 8 and 12 % v/v. Additionally, the impact of FA on biofilm formation was evaluated in the ten bacterial strains that were observed to be most resistant to FA. The results revealed that the inhibitory effects of FA were enhanced at lower pH values and at higher ethanol concentrations. LAB strains (such as Oenococcus oeni) were particularly sensitive to FA, whereas non-Oenococcus LAB strains demonstrated resistance to concentrations exceeding 2 g/L under the tested pH (3.5-4.0) and ethanol (0-12 % v/v) conditions. AAB strains (such as Acetobacter aceti) tolerated FA concentrations greater than 2 g/L at pH 4.0 in the absence of ethanol; however, the susceptibility increased with increasing ethanol concentrations and decreasing pH. Furthermore, FA significantly inhibited biofilm formation (particularly at a pH of 3.5 and ethanol concentrations greater than 8 % v/v). In conclusion, when combined with low pH and high ethanol concentrations, FA offers a promising strategy for controlling bacterial growth and biofilm formation in winemaking. This approach has the potential to complement or replace the use of traditional chemical preservatives, such as SO2.

RevDate: 2025-06-08

Gopalasamy K, Krishnamoorthy S, Somasundaram J, et al (2025)

Impact of Multispecies Biofilm on the Chemical and Mechanical Characteristics of Radicular Dentin from Diabetic and Non-Diabetic Patients: An in-vitro Study.

Journal of endodontics pii:S0099-2399(25)00319-X [Epub ahead of print].

INTRODUCTION: This in-vitro study examined the effect of a multispecies biofilm on the chemical characteristics and mechanical properties of root dentin from patients with or without type 2 diabetes mellitus (DM).

METHODS: Intact mandibular molars were obtained from diabetic and non-diabetic donors. Rectangular root dentin beams were prepared and categorized based on age (40-60 and 61-80 years), presence/absence of DM, and the site of dentin beam extraction (mesiodistal/buccolingual). Pentosidine, collagen cross-linking ratio, and mineral-to-collagen ratio were determined by Fourier-transform infrared spectroscopy (FTIR) and fatigue resistance was evaluated by the four-point flexure test to failure with or without exposure to a multispecies biofilm for 21 days.

RESULTS: DM and biofilm exposure significantly increased pentosidine, mineral-to-collagen ratio, and collagen cross-linking ratio in root dentin from both age groups (P<.05). Control root dentin from the 61-80 years group had significantly lower fatigue strength than root dentin from the 40-60 years group (P<.05). DM reduced the fatigue resistance of root dentin but not significantly (P>.05). After biofilm exposure, root dentin with DM had significantly lower fatigue resistance than root dentin without DM (P<.05). Biofilm exposure significantly reduced the fatigue resistance of root dentin with or without DM when compared with the controls only in the 40-60 years group (P<.05).

CONCLUSIONS: Aging decreased the fatigue resistance of root dentin. DM and biofilm exposure increased pentosidine, mineral-to-collagen ratio, and collagen cross-linking in root dentin across both age groups. Biofilm exposure further reduced the fatigue resistance of root dentin with DM compared to root dentin without DM.

RevDate: 2025-06-09

Shankar S, Murthy AN, Rachitha P, et al (2025)

Retraction notice to "Silk sericin conjugated magnesium oxide nanoparticles for its antioxidant, anti-aging, and anti-biofilm activities" [Environ. Res. 223 (2023) 115421].

Environmental research, 282:122031 pii:S0013-9351(25)01282-4 [Epub ahead of print].

RevDate: 2025-06-08

Hennebique A, Monge-Ruiz J, Roger-Margueritat M, et al (2025)

The hospital sink drain biofilm resistome is independent of the corresponding microbiota, the environment and disinfection measures.

Water research, 284:123902 pii:S0043-1354(25)00810-3 [Epub ahead of print].

In hospitals, the transmission of antibiotic-resistant bacteria (ARB) may occur via biofilms present in sink drains, which can lead to infections. Despite the potential role of sink drains in the transmission of ARB in nosocomial infections, routine surveillance of these drains is lacking in most hospitals. As a result, there is currently no comprehensive understanding of the transmission of ARB and the dissemination of antimicrobial resistance genes (ARGs) and associated mobile genetic elements (MGEs) via sink drains. This study employed a multifaceted approach to monitor the total aerobic bacteria as well as the presence of carbapenemase-producing Enterobacterales (CPEs), the microbiota and the resistome of sink drain biofilms (SDBs) and hospital wastewater (WW) of two separate intensive care units (ICUs) in the same healthcare facility in France. Samples of SDB and WW were collected on a monthly basis, from January to April 2023, in the neonatal (NICU) and the adult (AICU) ICUs of Grenoble Alpes University Hospital. In the NICU, sink drain disinfection with surfactants was performed routinely. In the AICU, routine disinfection is not carried out. Culturable aerobic bacteria were quantified on non-selective media, and CPEs were screened using two selective agars. Isolates were identified by MALDI-TOF MS, and antibiotic susceptibility testing (AST) was performed on Enterobacterales and P. aeruginosa. The resistome was analyzed by high-throughput qPCR targeting >80 ARGs and MGEs. The overall bacterial microbiota was assessed via full-length 16S rRNA sequencing. No CPEs were isolated from SDBs in either ICU by bacterial culture. Culture-independent approaches revealed an overall distinct microbiota composition of the SDBs in the two ICUs. The AICU SDBs were dominated by pathogens containing Gram-negative bacterial genera including Pseudomonas, Stenotrophomona, Klebsiella, and Gram-positive Staphylococcus, while the NICU SDBs were dominated by the Gram-negative genera Achromobacter, Serratia, and Acidovorax, as well as the Gram-positive genera Weisella and Lactiplantibacillus. In contrast, the resistome of the SDBs exhibited no significant differences between the two ICUs, indicating that the abundance of ARGs and MGEs is independent of microbiota composition and disinfection practices. The AICU WW exhibited more distinct aerobic bacteria than the NICU WW. In addition, the AICU WW yielded 15 CPEs, whereas the NICU WW yielded a single CPE. All the CPEs were characterized at the species level. The microbiota of the NICU and AICU WW samples differed from their respective SDBs and exhibited distinct variations over the four-month period:the AICU WW contained a greater number of genes conferring resistance to quinolones and integron integrase genes, whereas the NICU WW exhibited a higher abundance of streptogramin resistance genes. Our study demonstrated that the resistome of the hospital SDBs in the two ICUs of the investigated healthcare institute is independent of the microbiota, the environment, and the local disinfection measures. However, the prevalence of CPEs in the WW pipes collecting the waste from the investigated drains differed. These findings offer valuable insights into the resilience of resistance genes in SDBs in ICUs, underscoring the necessity for innovative strategies to combat antimicrobial resistance in clinical environments.

RevDate: 2025-06-06

Zhang R, Li W, Guo Z, et al (2025)

Valence Electron Fluctuation in a High-Entropy Oxide Heterojunction Enables Collaborative Photodynamic and Mild-Thermal Therapy for Cutaneous Biofilm Infections.

ACS nano [Epub ahead of print].

Mild photothermal therapy combined with photodynamic therapy has emerged as an effective treatment for antibiotic-resistant infection. However, controlling operation temperature within a safe range during reactive oxygen species (ROS) production remains a challenge. Herein, we present a functional heterojunction consisting of Ti3C2Tx-MXene and (CoCrFeMnNi)3O4 high-entropy oxide (HEO) featuring a valence electron fluctuation effect, achieving a highly efficient treatment of biofilm-associated infections in wounds and abscesses under mild conditions where skin temperature remains below 42.3 °C. We found that under near-infrared light irradiation, photogenerated hot electrons from MXene are efficiently transferred to the HEO surface, serving as abundant electron sources. The electron fluctuation effect of the HEO enables the rapid enrichment and activation of oxygen molecules in microenvironments, significantly enhancing ROS generation. Simultaneously, the built-in electric field at the MXene-HEO interface suppresses electron-hole recombination, minimizing excessive heat generation and ensuring efficient photothermal-photodynamic synergy. The accelerated generation of ROS inhibits the synthesis of adenosine triphosphate (ATP) by disrupting the bacterial respiratory chain complex (RCC), which significantly inhibits the expression of ATP-dependent molecular chaperone genes groEL and ClpP, compromising bacterial heat resistance and virulence to achieve mild thermal therapy. Moreover, it also shows superior benefits in tissue regeneration, collagen deposition, and angiogenesis while alleviating the inflammation, exhibiting a robust solution for drug-resistant bacterial biofilms in cutaneous tissues. Our work highlights the potential of HEO functional heterojunctions for safe and effective mild-temperature biomedical therapies and paves the way for advanced strategies in combating biofilm-associated infections through rational material design and engineering.

RevDate: 2025-06-06
CmpDate: 2025-06-06

Ravidà A, Dias DR, Lemke R, et al (2025)

Efficacy of Decontamination Methods for Biofilm Removal from Dental Implant Surfaces and Reosseointegration: An AAP/AO Systematic Review on Peri-implant Diseases and Conditions.

The International journal of oral & maxillofacial implants.

PURPOSE: To evaluate the nonclinical evidence concerning the efficacy of different decontamination methods in facilitating reosseointegration, eliminating biofilm from implant surfaces, and their potential to induce adverse surface modifications and release of material remnants.

MATERIALS AND METHODS: Systematic electronic and manual searches were conducted to identify publications involving animal or human block biopsies, ex vivo/in situ studies, and in vitro studies. Mechanical, chemical, and electrolytic methods for implant decontamination were presented in a descriptive analysis.

RESULTS: A total of 121 studies were included, namely 46 involving animal/human biopsies, 39 ex vivo/in situ experiments, and 36 in vitro investigations. No modality demonstrated significant superiority in terms of reosseointegration outcomes. Ex vivo, in situ, and in vitro studies reported that greater biofilm removal from implant surfaces occurred with polyetheretherketone (PEEK) ultrasonic tips, air-powder abrasive (APA), erbium: yttrium-aluminum-garnet (Er:YAG) laser, and electrolytic cleaning. Minimal surface alterations were noted with soaked cotton pellets, APA, specific settings of Er:YAG laser, erbium, chromium: yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser, electrolytic treatment, and cold atmospheric plasma. Titanium or stainless steel curettes, ultrasonic tips, titanium brushes, and implantoplasty induced significant surface alterations and peak flattening of implant threads. Plastic and carbon curettes as well as PEEK ultrasonic tips and APA left material remnants.

CONCLUSIONS: Implant reosseointegration is possible following appropriate surface decontamination. Application of Er:YAG laser, electrolytic cleaning, and APA stand out as the methods that most closely embody the ideal characteristics of an effective decontamination protocol.

RevDate: 2025-06-05

Ferreira Fonseca de Fraga FB, Dalberto PF, Bizarro CV, et al (2025)

Egg proteins of Anagasta kuehniella (Lepidoptera: Pyralidae) inhibit Staphylococcus epidermidis biofilm formation.

Microbial pathogenesis pii:S0882-4010(25)00505-4 [Epub ahead of print].

Bacterial biofilms are increasing its tolerance to conventional antimicrobial treatments. In this context biofilm formation becomes an important target to control pathogenic bacteria. Arthropods are known to be an important source of natural products; however, investigations exploring the biological activities of arthropod eggs are scarce. So, in this study we investigated the antibiofilm activity of the Mediterranean flour moth Anagasta kuehniella compounds against Staphylococcus epidermidis. The antibiofilm activity of organic and aqueous extractions performed on the eggs was assessed using the crystal violet method and scanning electron microscopy (SEM). Egg's aqueous extract (AE) inhibits up to 65% biofilm formation by S. epidermidis. Heat and enzymatic treatments indicated that activity was related to protein. A partial purified active fraction (F9) was obtained by size exclusion chromatography and SDS-PAGE were performed using AE and F9. Mass spectrometry was used to identify the proteins in the F9. SEM analysis showed this fraction inhibits bacterial aggregates in treated S. epidermidis biofilms without alteration on bacterial cell morphology. Our results showed that proteins present in A. kuehniella eggs inhibit biofilm formation without killing S. epidermidis and reinforces the idea that arthropods are a potential source of natural products useful for biotechnology.

RevDate: 2025-06-05

Brindhadevi K, Le QH, Salmen SH, et al (2025)

Retraction notice to "In vitro biofilm inhibition efficacy of Aerva lanata flower extract against Gram negative and Gram-positive biofilm forming bacteria and toxicity analysis using Artemia salina" [Environ. Res. 238-P1 (2023) 117118].

Environmental research, 282:121993 pii:S0013-9351(25)01244-7 [Epub ahead of print].

RevDate: 2025-06-05

Wang CT, Vasumathi K, Tumboimbela JRW, et al (2025)

Temperature-driven changes in biofilm formation and electrochemical performance of deep-sea inoculum in microbial fuel cells.

Bioelectrochemistry (Amsterdam, Netherlands), 166:109012 pii:S1567-5394(25)00115-X [Epub ahead of print].

Microbial fuel cells (MFCs) generate electricity by converting organic materials and utilizing electroactive bacteria, where anodic biofilms play a vital role in electron transfer and controlling internal resistance. The adaptation of deep-sea microbial communities to diverse environmental conditions, particularly the effects of temperature on biofilm formation and MFC efficiency in high-salinity environments, remains under-explored. This study aims to fill this gap by examining how different temperatures (4 °C (F35), 25 °C (R35), and 37 °C (I35)) affect anodic biofilm formation and MFC performance. The research employs deep-sea sediment inoculum from the South China Sea to enhance understanding of microbial adaptability and optimize performance in extreme conditions. Among the tested conditions, I35 demonstrated the highest current and power densities at 172.49 mA/m[2] and 20.09 mW/m[2], representing increases of approximately 129 % and 350 % compared to F35. R35 displayed moderate output. Microbial analysis revealed that I35 had the highest CFU count at 7.67 × 10[7] CFU/mL, with Gram staining and colony morphology indicating greater diversity and a higher abundance of electroactive Gram-negative populations at elevated temperatures. Performance improved with increased temperature; however, the power gains were more significant than variations in microbial counts, underscoring the importance of microbial composition, biofilm conductivity, and electron transfer efficiency. Despite having viable bacteria, F35 showed low output due to a less electroactive community and considerable charge transfer resistance. These findings highlight the need to enhance microbial quality, not just quantity, to improve MFC performance in extreme conditions and support the future application of thermally adapted biofilms in high-salinity MFC systems.

RevDate: 2025-06-07

Ma L, Liu Y, Zheng X, et al (2025)

Isolation and characterization of methicillin-resistant Staphylococcus aureus phage SPB against MRSA planktonic cells and biofilm.

Frontiers in microbiology, 16:1554182.

Methicillin-resistant Staphylococcus aureus (MRSA) is a common antibiotic-resistant pathogen. MRSA and its biofilm pose a great threat to the food industry. In this study, we characterized the biological properties and antibacterial efficacy of phages through the double-layer plate method, transmission electron microscopy (TEM), whole-genome sequencing (WGS), bioinformatic analyses, fluorescence microscopy, and biofilm eradication assays. The results demonstrated that phage SPB is a virulent member of the genus Kayvirus (subfamily Twortvirinae), exhibited a broad host range spanning Staphylococcus species. It effectively lysed 97.3% (36/37) of clinical MRSA isolates and 100.0% (10/10) of coagulase-negative staphylococci strains tested. The optimal multiplicity of infection (MOI) was determined to be 1, with a latent period of 10 min. Environmental stability assays revealed that phage SPB maintained infectivity across temperatures ranging from 4°C to 50°C and pH values between 4 and 11. Genomic analysis showed that phage SPB possesses a 143,170 bp genome with a G+C content of 30.2%, encoding 218 putative coding sequences (CDSs), 3 tRNAs, and no virulence factors were identified through in software screening. Phage SPB exhibited potent inhibition of planktonic bacterial growth. Furthermore, at varying multiplicities of infection (MOIs), it significantly suppressed biofilm formation and eradicated pre-existing biofilms, with statistical significance (P < 0.001). These results suggest that phage SPB can be used as a potential antimicrobial agent to prevent and remove MRSA and its biofilm from food processing.

RevDate: 2025-06-04

Hamad D, Hassanein EHM, Salem SH, et al (2025)

Synthesis of ZIF-67 Nanoparticles for Camel Whey Protein Delivery: Promising Antioxidant, Anti-inflammatory, Anticancer Effects, and Anti-biofilm Activity.

Molecular biotechnology [Epub ahead of print].

Camel whey protein (CWP) offers various health benefits, including immune enhancement, anti-inflammatory, anticancer, and antibacterial properties. It also possesses antioxidant activity. However, its limited efficacy and stability restrict its broader application. Metal-organic frameworks (MOFs) are crystalline materials composed of multiple organic groups and metal ions, known for their unique structural properties. In this study, we aimed to synthesize and evaluate the biological activity of a CWP-Co-MOF conjugate. The structural characterization of the synthesized materials was conducted using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) analysis. The comparison of the XRD and FTIR patterns of ZIF-67, CWP and CWP-Co-MOF conjugate indicate successful conjugation of CWP with ZIF-67, confirming the structural integrity of the conjugate. The EDX maps further corroborate the effective conjugation of CWP with ZIF-67. The conjugated CWP-MOF nanoparticles (NPs) exhibited promising antioxidant activity, as assessed by the DPPH assay. Furthermore, they showed more potent anti-inflammatory effects in LPS-induced BV2 microglial cells and superior anticancer activity against HepG2 and Caco-2 cell lines, as determined by the MTT assay and flow cytometry, compared to free CWP. Additionally, the CWP-MOF-NPs exhibited enhanced antimicrobial properties and increased efficacy as an anti-biofilm agent against pathogenic bacteria.

RevDate: 2025-06-07
CmpDate: 2025-06-05

Nilsson DPG, Wiklund K, Malyshev D, et al (2025)

3D-printed temperature and shear stress-controlled rocker platform for enhanced biofilm incubation.

Scientific reports, 15(1):19575.

Growing biofilms of thermophilic (heat-loving) and psychrotrophic (cold-tolerant) bacteria pose several challenges due to specific environmental requirements. Thermophilic bacteria typically grow between 45 and 80 [Formula: see text]C, while psychrotrophic bacteria thrive between 0 and 15 [Formula: see text]C. Maintaining the precise temperature and fluid conditions required for biofilm growth can be technically challenging. To overcome these challenges, we designed the Bio-Rocker, a temperature- and shear stress-controlled rocker platform for biofilm incubation. The platform supports temperatures between - 9 and 99 [Formula: see text]C, while its digital controller can adjust the rocking speed from 1 to 99[Formula: see text]/s and set rocking angles up to ±19[Formula: see text]. This ability, together with data from analytical models and multi-physics simulations, provides control over the shear stress distribution at the growth surfaces, peaking at 2.4 N/m[Formula: see text]. Finally, we evaluated the system's ability to grow bacteria at different temperatures, shear stress, and materials by looking at the coverage and thickness of the biofilm, as well as the total biomass. A step-by-step guide, 3D CAD files, and controller software is provided for easy replication of the Bio-Rocker, using mostly 3D-printed and off-the-shelf components. We conclude that the Bio-Rocker's performance is comparable to high-end commercial systems like the Enviro-Genie (Scientific Industries) yet costs less than $350 dollars to produce.

RevDate: 2025-06-04
CmpDate: 2025-06-04

Li Y, Liu Y, Zheng B, et al (2025)

Multicellular behavior and genomic characterization of Salmonella Typhimurium in animal-derived food chains in Xinjiang, China: Phenotypic resistance, biofilm formation, and sequence types.

Food research international (Ottawa, Ont.), 214:116698.

Salmonella Typhimurium Is a globally significant foodborne pathogen that causes diseases in livestock and poultry, which can lead to human infections and fatalities through contaminated food. In this study, we investigated the prevalence of Salmonella Typhimurium in the animal-derived food chain in Xinjiang, China. Among 5075 samples, the detection rate of Salmonella was 8.26 % (419/5075). Of these isolates, 27.21 % (114/419) were identified as Salmonella Typhimurium. Phenotypic analysis revealed significant antibiotic resistance: 82.46 % (94/114) of the strains exhibited multidrug resistance (MDR), with high resistance rates to amoxicillin / clavulanic acid, ampicillin, and tetracycline. Congo red plate assays demonstrated that 62.28 % (71/114) of the strains exhibited multicellular behavior (RDAR morphotype). Biofilm formation assays indicated that 96.49 % (110/114) of the strains possessed biofilm-forming capabilities, with 18.18 % (20/110) showing strong biofilm formation. Notably, strains displaying multicellular behavior exhibited enhanced biofilm formation, and biofilm capability was positively correlated with antibiotic resistance phenotypes. Whole-genome sequencing of 40 representative strains identified four sequence types (ST19, ST34, ST99, ST128), with ST34 being the most predominant. Distinct host preferences were observed: ST34 strains originated exclusively from cattle and sheep, while ST19, ST99, and ST128 strains were isolated from geese and pigeons. Resistance gene profiling revealed that strains harboring resistance genes exhibited stronger resistance phenotypes, while ST99 and ST128 strains lacked detectable resistance genes. Plasmids R64, R478, and pKPC_CAV1321 were identified in cattle- and sheep-derived strains, whereas pSLT-BT and pSPCV plasmids were predicted in strains from geese and pigeons. Pan-genome analysis and phylogenetic reconstruction demonstrated distinct genetic clustering among ST types, with ST19 and ST128 showing closer evolutionary relationships. This study provides comprehensive insights into the prevalence, phenotypic characteristics, and genomic diversity of Salmonella Typhimurium in the animal-derived food chain in Xinjiang. Our findings contribute to region-specific pathogen control strategies, enhancing public health safety and consumer protection.

RevDate: 2025-06-08
CmpDate: 2025-06-04

Sanches CVG, Terada RSS, Ramos AL, et al (2025)

In vitro evaluation of biofilm formation by Streptococcus mutans and Candida albicans in orthodontic aligners.

Dental press journal of orthodontics, 30(2):e2524192.

INTRODUCTION: Aligners have been used by the orthodontic community for approximately 20 years, but little research has been carried out on the accumulation of biofilm on the surface of these aligners, as well as their possible impact on the oral ecosystem.

METHODS: Ten hemi-arches of Invisalign® brand orthodontic aligners were used. The hemi-arches were placed inside sterile flasks containing 25 mL of Gibbons and Nygaard broth, with standardized suspensions of the two microorganisms on the 0.5 MacFarland scale and incubated in aerophily (C. albicans) and microaerophily (S. mutans and mixed biofilm) at 37°C for 72h. The biofilm formed was removed by the multiple rinses method to quantify the microorganisms in the biofilms in CFU/mL. A qualitative analysis with scanning electron microscopy was performed to observe the structure of the formed biofilms.

RESULTS: It was observed the accumulation of a monospecies biofilm (S. mutans - 2.55 x 106 and C. albicans - 1.62 x 107) and mixed biofilm (S. mutans - 2.21 x 105 and C. albicans - 1.06 x 107) very robust on the surface of orthodontic aligners.

CONCLUSION: According to the results obtained, one can conclude that Invisalign® brand orthodontic aligners are susceptible to the accumulation of monospecies and mixed biofilms of S. mutans and C. albicans. Therefore, it is necessary to consider the possibility of Invisalign® users developing carious lesions associated with the biofilm formed by these two microbial species, and to guide the patient on the correct cleaning of the device during treatment.

RevDate: 2025-06-04

Wang L, Fu H, Zhao J, et al (2025)

Cascade Magnetic Hyperthermia Therapy for Biofilm Eradication and Bone Regeneration via Dual Osteoimmuno-regulation.

ACS nano [Epub ahead of print].

Infected bone defects (IBDs) treatment presents a great challenge in current orthopedics due to the complex nature of these defects, and the diversified demands involving infection control and subsequent bone regeneration. Current-available treatments often fail to address these multifaceted needs effectively. Herein, we propose a cascade magnetic hyperthermia therapy (cMHT) strategy using MNP-PEI-siCkip-1 (MPSC), a magnetogenetic nanoplatform constructed by coating siRNA for casein kinase-2 interacting protein-1 (siCkip-1) and polyethylenimine-carboxylic acid (PEI-COOH) on ZnCoFe2O4@ZnMnFe2O4 nanoparticles. These MPSCs were then embedded in gelatin methacryloyl (GelMA) to form a nanocatalytic nanoparticle-hydrogel composite (MSG), which exhibited a strong magnetothermal effect. During the disinfection period, the MSG hydrogel generates MHT (∼50 °C) under alternative magnetic field (AMF) to destroy dense biofilm, and catalytically produce hydroxyl radicals (•OH) in biofilm microenvironment (BME) for anti-infection. Increased •OH production also promotes the proinflammation regulation of innate immunity for bacteria eradication. After the infection elimination, AMF was tuned to induce mild MHT (∼41 °C, mMHT) to promote osteogenesis and suppress excessive inflammation. Gradual MSG hydrogels degradation releases MPSCs, delivering siCkip-1 possessing osteogenic and anti-inflammatory activities to osteoblasts and macrophages. This cascade magnetic hyperthermia therapy (cMHT) strategy offers a compelling solution to the multifaceted challenges of IBD treatment, addressing critical aspects such as infection control and bone regeneration. The innovative approach underscores a promising potential of cMHT as transformative therapeutic option for IBDs, which may lead to improved treatment outcomes.

RevDate: 2025-06-04
CmpDate: 2025-06-04

Scott E, C Burkhart (2025)

A Review of the Role of C. Acnes and its Biofilm in Dandruff Pathogenesis.

Journal of drugs in dermatology : JDD, 24(6):566-569.

Dandruff is a common skin condition affecting up to half of the world's population. Symptoms include pruritus, inflammation, and flaking. It is thought to be in part due to microbe dysbiosis. This paper aims to discuss the relationship between dandruff and Cutibacterium acnes (C. acnes). It will also explore the potential role of C. acnes's biofilm in the formation of the biological glue that sticks dandruff flakes together. Citation: Scott E, Burkhart C. A review of the role of Cutibacterium acnes and its biofilm in dandruff pathogenesis. J Drugs Dermatol. 2025;24(6):566-569. doi:10.36849/JDD.8648R1.

RevDate: 2025-06-04

Florenço AMA, de Moura SST, Dos Santos Medeiros SMFR, et al (2025)

β-Lapachone encapsulated into stealth liposomes: inhibition of biofilm and cell wall thickness of MRSA.

Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology] [Epub ahead of print].

RevDate: 2025-06-03

Zheng Z, Lyu H, Wang L, et al (2025)

Microplastic biofilm may shape microbial community enriched with antibiotic resistance genes to enhance nitrogen transformation under antibiotic stress.

Journal of hazardous materials, 494:138796 pii:S0304-3894(25)01712-1 [Epub ahead of print].

The response of nitrogen transformation to microplastic biofilm under antibiotics (ATs) stress as well as the interrelationships between functional genes and microorganisms in surface water are not very well understood and need further investigation. This study investigated the response of nitrogen transformation by analyzing changes in various nitrogen forms and explored the interaction between nitrogen transformation functions and antibiotic resistance genes (ARGs) under exposure to ATs (ciprofloxacin (CIP) and tetracycline (TC)) and PVC biofilm. Compared to the control, exposure to mature polyvinyl chloride (PVC) biofilm increased nitrate nitrogen (NO3[-]-N) and ammonia nitrogen (NH4[+]-N) removal by 12.48 % and 8.79 %, with the NO3[-]-N removal rate constant reaching 0.17. However, co-exposure to CIP significantly inhibited nitrogen transformation, reducing the NO3[-]-N removal rate constant to 0.08. In PVC biofilm, more active nitrogen transformation and enhanced horizontal transfer of ARGs led to a stronger positive correlation between nitrogen transformation genes (NTGs) and ARGs. Microorganisms carrying NTGs largely overlapped with ARGs host species, including Hydrogenophaga, Rhodococcus, and Ignavibacterium, which exhibited high abundance of both gene types. This indicated that PVC biofilm facilitated nitrogen transformation under ATs stress by enriching nitrogen transformation microorganisms carrying high ARGs abundance. These results extended knowledge of effects of ATs and microplastics (MPs) on nitrogen transformation in surface water and provided theoretical support for unique ecological effects of microplastic biofilm.

RevDate: 2025-06-03

Lormand JD, Savelle CH, Teschler JK, et al (2025)

Secreted retropepsin-like enzymes are essential for stress tolerance and biofilm formation in Pseudomonas aeruginosa.

mBio [Epub ahead of print].

Proteases regulate important biological functions. Here, we present the structural and functional characterization of three previously uncharacterized aspartic proteases in Pseudomonas aeruginosa. We show that these proteases have structural hallmarks of retropepsin peptidases and play redundant roles for cell survival under hypoosmotic stress conditions. Consequently, we named them retropepsin-like osmotic stress tolerance peptidases (Rlo). Our research shows that while Rlo proteases are homologous to RimB, an aspartic peptidase involved in rhizosphere colonization and plant infection, they contain N-terminal signal peptides and perform distinct biological functions. Mutants lacking all three secreted Rlo peptidases show defects in antibiotic resistance, biofilm formation, and cell morphology. These defects are rescued by mutations in the inactive transglutaminase transmembrane protein RloB and the cytoplasmic ATP-grasp protein RloC, two previously uncharacterized genes in the same operon as one of the Rlo proteases. These studies identify Rlo proteases and rlo operon products as critical factors in clinically relevant processes, making them appealing targets for therapeutic strategies against Pseudomonas infections.IMPORTANCEBacterial infections have become harder to treat due to the ability of pathogens to adapt to different environments and the rise of antimicrobial resistance. This has led to longer illnesses, increased medical costs, and higher mortality rates. The opportunistic pathogen Pseudomonas aeruginosa is particularly problematic because of its inherent resistance to many antibiotics and its capacity to form biofilms, structures that allow bacteria to withstand hostile conditions. Our study uncovers a new class of retropepsin-like proteases in P. aeruginosa that are required for biofilm formation and bacterial survival under stress conditions, including antibiotic exposure. By identifying critical factors that determine bacterial fitness and adaptability, our research lays the foundation for developing new therapeutic strategies against bacterial infections.

RevDate: 2025-06-03

Pandey NK, Alkhatib AEA, S Hazra (2025)

Draft genome sequence of biofilm-forming Pseudomonas aeruginosa HLHR and non-biofilm-producing Pseudomonas sp. HLMP isolated from vermicompost.

Microbiology resource announcements [Epub ahead of print].

We announce the draft genomes of Pseudomonas aeruginosa HLHR and Pseudomonas sp. HLMP isolated from a vermicompost sample.

RevDate: 2025-06-03

Agustín MDR, Genovese DB, Palencia Díaz MA, et al (2025)

Efficacy of natamycin to reduce adhesion and biofilm formation of multispecies yeast biofilms on variable flow conditions.

Biofouling [Epub ahead of print].

This study evaluated the effectiveness of natamycin (NAT) on multispecies yeast biofilms isolated from ultrafiltration membranes in an apple juice processing industry. Biofilms were developed on stainless steel surfaces using 12° Brix apple juice under static (SC) and laminar flow (LF) conditions. NAT (0.01 mM) was applied from the beginning of the adhesion stage (NAT T0) and on 24-h-preformed biofilms (NAT T24). NAT T0 significantly reduced attachment and biofilm formation by ∼4-log10 units after 48 h, while NAT T24 achieved reductions of 1.83 and 0.79-log10 units in SC and LF, respectively. The overall reduction in total cell count was significantly more pronounced and consistent under SC. This highlights the importance of preventing initial adhesion for controlling biofilm development. Additionally, these findings underscore the importance of evaluating antimicrobial agents in dynamic flow conditions that closely mimic real-world applications.

RevDate: 2025-06-03

Yu L, Xu L, Zhao Y, et al (2025)

The role of YbdO in regulating acid resistance and biofilm formation in avian pathogenic Escherichia coli.

Avian pathology : journal of the W.V.P.A [Epub ahead of print].

Avian pathogenic Escherichia coli (APEC) causes severe systemic infectious diseases known as colibacillosis in avian species, resulting in significant economic losses to the poultry industry worldwide, and threatening food security and human health. Previous studies show that acid resistance is an indispensable mechanism that allows E. coli to survive in the gastrointestinal tract; and biofilm formation results in persistent and recurrent infections in the host, and is the main reason for the difficult treatment of colibacillosis with antimicrobial agents. In this study, we confirmed YbdO as a transcriptional regulator that increased biofilm formation by upregulating the transcription of the biofilm-associated genes bcsE, csgD, pgaA, wcaD, fimH, and flhD and acid resistance by activating the expression of acid stress chaperone HdeA and acid stress response protein YqgB in APEC CE1. Additionally, electrophoretic mobility shift assay (EMSA) indicated that YbdO directly activated the expression of CsgD, HdeA and YqgB by directly binding to the promoters of csgD, hdeA and yqgB, respectively. These findings demonstrate the regulatory mechanism of YbdO on acid resistance and biofilm formation and enhance our understanding of how APEC improves the adaptability to environmental stresses, thereby increasing the pathogenicity of APEC. Therefore, this study might provide a paradigm for the regulation of biofilm formation and acid resistance that can be used to study other bacterial pathogens.

RevDate: 2025-06-03

van Dun SCJ, Knol R, Silva-Herdade AS, et al (2025)

Machine learning assisted classification of staphylococcal biofilm maturity.

Biofilm, 9:100283.

An increasing incidence of device-related, biofilm-associated infections has been observed in clinical practice worldwide. In vitro biofilm models are essential to study these burdensome infections and to design and test potential new treatment approaches. However, there is considerable variation in in vitro biofilm models, and a generally accepted systematic description of biofilm maturity - apart from incubation time - is lacking. Therefore, we proposed a scheme comprised of 6 different classes based on common topographic characteristics, i.e., the substrate, bacterial cells and extracellular matrix, identified by atomic force microscopy (AFM), to describe biofilm maturity independent of incubation time. Evaluation of a test set of staphylococcal biofilm images by a group of independent researchers showed that human observers were capable of classifying images with a mean accuracy of 0.77 ± 0.18. However, manual evaluation of AFM biofilm images is time-consuming, and subject to observer bias. To circumvent these disadvantages, a machine learning algorithm was designed and developed to aid in classification of biofilm images. The designed algorithm was capable of identifying pre-set characteristics of biofilms and able to discriminate between the six different classes in the proposed framework. Compared to the established ground truth, the mean accuracy of the developed algorithm amounted to 0.66 ± 0.06 with comparable recall, and off-by-one accuracy of 0.91 ± 0.05. This algorithm, which classifies AFM images of biofilms, has been made available as an open access desktop tool.

RevDate: 2025-06-03
CmpDate: 2025-06-03

Kincses A, Ghazal TSA, Veres K, et al (2025)

Phenolic compounds from Origanum majorana with biofilm-inhibitory activity against methicillin-resistant Staphylococcus aureus and Escherichia coli strains.

Pharmaceutical biology, 63(1):402-410.

CONTEXT: Antibiotic resistance in bacteria is a growing global problem, with biofilm formation and efflux pumps playing crucial roles in this issue.

OBJECTIVE: This study explores the effects of phenolic compounds of Origanum majorana against Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA) strains by inhibiting biofilm formation and efflux pumps.

MATERIALS AND METHODS: The methanolic extract of O. majorana was fractionated guided by an antibiofilm assay, and the active fractions were analyzed by multistep chromatographic separation to yield five pure compounds. Their structures were then determined using 1D and 2D nuclear magnetic resonance spectroscopy. The minimum inhibitory concentrations of the extracts, fractions, and isolated compounds were determined via the microdilution method in a 96-well plate. Antibiofilm activity was assessed using the crystal violet method, and the effect on efflux pumps was tested by a real-time ethidium bromide accumulation assay.

RESULTS: Arbutin (1), apigenin 7-O-glucoside (2), 6'-caffeoylarbutin (3), rosmarinic acid (4), and 2-deoxy-d-1,4-ribonolactone (5) were isolated from the aqueous methanolic extract. Compounds 1, 2, and 4 reduced E. coli biofilm formation by 24.82%-42.98% at 100 µM, whereas only arbutin (1) moderately suppressed biofilm formation of MRSA (23.15 ± 1.56% at 50 µM). Arbutin also demonstrated efflux pump inhibitory activity against MRSA (relative fluorescence index of 0.49 at 100 µM).

DISCUSSION AND CONCLUSIONS: The newly discovered natural antibiofilm agents show promise as candidates for treating biofilm-associated infections and combating antibiotic-resistant bacteria.

RevDate: 2025-06-03

Long X, He Y, Wang A, et al (2025)

Lysozyme Fiber-Inspired Versatile Supramolecular Hydrogel Against Drug-Resistant Pathogens and Biofilm Formation.

Advanced healthcare materials [Epub ahead of print].

Multidrug-resistant (MDR) bacterial infections pose a significant threat to human health, particularly when introduced by surgical contamination, resulting in early-stage implant-related biofilm infections and potential implant failure. Inspired by the structure and function of lysozyme fibers, a biomimetic supramolecular hydrogel is developed that mimics the lysozyme fiber architecture and encapsulates D-tyrosine (D-Tyr), integrating bactericidal and anti-biofilm functions within a self-assembled positively charged nanofibrous network. The peptide backbone with quaternary ammonium salt-modified fibers disrupts bacterial cell membranes through direct contact, thereby damaging structural integrity, causing cytoplasmic leakage and killing bacteria; meanwhile, D-Tyr's effective sustained release inhibits initial bacterial contamination and prevents subsequent biofilm formation. In vivo, experiments demonstrated that the hydrogel significantly accelerated the healing of Methicillin-resistant Staphylococcus aureus (MRSA)-infected skin abscesses and prevented implant-related biofilm infections during the preliminary stages of implantation. By exploiting synergistic bactericidal and anti-biofilm effects, this lysozyme fiber-inspired hydrogel offers a promising strategy to combat MDR bacterial infections and prevent biofilm-related implant complications.

RevDate: 2025-06-04

Shrestha P, Kim B, Han SR, et al (2025)

Unraveling the genetic mechanisms of UV radiation resistance in Bacillus through biofilm formation, sporulation, and carotenoid production.

Genomics, 117(4):111066 pii:S0888-7543(25)00082-5 [Epub ahead of print].

Bacillus species are Gram-positive bacteria that are rod-shaped, endospore-forming, and aerobic or facultatively anaerobic. With over 300 recognized species, Bacillus subtilis stands out as a well-studied model organism. The genus's various species exhibit a wide range of physiological capabilities, allowing them to thrive in diverse environmental conditions. Each cell produces a single endospore, which is highly resistant to heat, cold, radiation, desiccation, and disinfectants. Among Bacillus strains, those capable of producing spores, biofilms, and carotenoids demonstrate significant resilience to UV light. This review examines the genes involved in spore formation, biofilm development, and carotenoid synthesis, emphasizing their roles in UV radiation survival. We explore the interconnections between these processes and their combined contribution to UV resistance, focusing on the underlying genetic mechanisms. These insights will benefit researchers studying the genetic basis of UV radiation resistance in Bacillus species. IMPORTANCE: Bacteria employ adaptive strategies in extreme environments through rapid changes in gene expression, altering their phenotype for survival. Bacillus species, for example, defend against UV radiation by making spores, creating biofilms, and producing pigments. During sporulation, sigma factors (σ[F], σ[E], σ[G], and σ[K]) regulate gene expression to adapt to environmental shifts. It has been found that the spores of some species may contain pigments that strongly absorb UV radiation, playing a crucial role in spore UV resistance. UV light penetrates biofilm matrices minimally, mainly affecting surface cells, which produce compounds like mycosporine-like amino acids and carotenoids to shield against UV damage.

RevDate: 2025-06-02

Stabile Gouveia J, Paula Castro V, Rossi F, et al (2025)

Quantifying biofilm matrix components: effects of chlorhexidine and orthophthalaldehyde on Candida parapsilosis and Staphylococcus aureus.

Biofouling [Epub ahead of print].

Candida and Staphylococcus species are responsible for hospital-acquired infections, forming resilient biofilms. This study evaluated the impact of biocides on the biofilm matrix components of Candida parapsilosis and Staphylococcus aureus in monospecies and mixed biofilms. Proteins, carbohydrates, and extracellular DNA (eDNA) were quantified using the Bradford reagent, phenol-sulfuric acid, and silica column extraction with spectrophotometric readings at 260 and 280 nm. Biofilms were treated with 0.5% chlorhexidine (CLX) and 0.55% ortho-phthalaldehyde (OPA) for 3 and 10 min, respectively. Results showed a significant protein increase (8.6 ± 4.94 µg/mL for C. parapsilosis and 17.25 ± 1.86 µg/mL for S. aureus) after CLX and OPA exposure, especially in isolates 935 M, 936 C, and S. aureus biofilms (p < 0.01). Carbohydrates significantly decreased (p < 0.0001), with CLX generally more effective than OPA. eDNA levels increased across all samples. These findings suggest that CLX and OPA alter biofilm matrix composition, facilitating antimicrobial efficacy.

RevDate: 2025-06-02

Liu Y, Gates AD, Liu Z, et al (2025)

In vitro biofilm formation by a beneficial bacterium partially predicts in planta protection against rhizosphere pathogens.

The ISME journal pii:8154967 [Epub ahead of print].

Plant roots form associations with beneficial and pathogenic soil microorganisms. Although members of the rhizosphere microbiome can protect against pathogens, the mechanisms are poorly understood. We hypothesized that the ability to form a biofilm on the root surface is necessary for the exclusion of pathogens; however, it is not known if the same biofilm formation components required in vitro are necessary in vivo. Pseudomonas brassicacearum WCS365 is a beneficial strain that is phylogenetically closely related to an opportunistic pathogen Pseudomonas sp. N2C3 and confers protection against N2C3 in the rhizosphere. We used this plant-mutualist-pathogen model to screen collections of P. brassicacearum WCS365 increased attachment mutants (iam) and surface attachment defective (sad) transposon insertion mutants that form increased or decreased biofilm on abiotic surfaces, respectively. We found that whereas the P. brassicacearum WCS365 mutants had altered biofilm formation in vitro, only a subset of these mutants lost protection against N2C3. Non-protective mutants those involved in large adhesion protein (LapA) biosynthesis, flagellar synthesis and function, and O-antigen biosynthesis. We found that the inability of P. brassicacearum WCS365 mutants to grow in planta, and the inability to suppress pathogen growth, both partially contributed to loss of plant protection. We did not find a correlation between the extent of biofilm formed in vitro and pathogen protection in planta indicating that biofilm formation on abiotic surfaces may not fully predict pathogen exclusion in planta. Collectively, our work provides insights into mechanisms of biofilm formation and host colonization that shape the outcomes of host-microbe-pathogen interactions.

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ESP Quick Facts

ESP Origins

In the early 1990's, Robert Robbins was a faculty member at Johns Hopkins, where he directed the informatics core of GDB — the human gene-mapping database of the international human genome project. To share papers with colleagues around the world, he set up a small paper-sharing section on his personal web page. This small project evolved into The Electronic Scholarly Publishing Project.

ESP Support

In 1995, Robbins became the VP/IT of the Fred Hutchinson Cancer Research Center in Seattle, WA. Soon after arriving in Seattle, Robbins secured funding, through the ELSI component of the US Human Genome Project, to create the original ESP.ORG web site, with the formal goal of providing free, world-wide access to the literature of classical genetics.

ESP Rationale

Although the methods of molecular biology can seem almost magical to the uninitiated, the original techniques of classical genetics are readily appreciated by one and all: cross individuals that differ in some inherited trait, collect all of the progeny, score their attributes, and propose mechanisms to explain the patterns of inheritance observed.

ESP Goal

In reading the early works of classical genetics, one is drawn, almost inexorably, into ever more complex models, until molecular explanations begin to seem both necessary and natural. At that point, the tools for understanding genome research are at hand. Assisting readers reach this point was the original goal of The Electronic Scholarly Publishing Project.

ESP Usage

Usage of the site grew rapidly and has remained high. Faculty began to use the site for their assigned readings. Other on-line publishers, ranging from The New York Times to Nature referenced ESP materials in their own publications. Nobel laureates (e.g., Joshua Lederberg) regularly used the site and even wrote to suggest changes and improvements.

ESP Content

When the site began, no journals were making their early content available in digital format. As a result, ESP was obliged to digitize classic literature before it could be made available. For many important papers — such as Mendel's original paper or the first genetic map — ESP had to produce entirely new typeset versions of the works, if they were to be available in a high-quality format.

ESP Help

Early support from the DOE component of the Human Genome Project was critically important for getting the ESP project on a firm foundation. Since that funding ended (nearly 20 years ago), the project has been operated as a purely volunteer effort. Anyone wishing to assist in these efforts should send an email to Robbins.

ESP Plans

With the development of methods for adding typeset side notes to PDF files, the ESP project now plans to add annotated versions of some classical papers to its holdings. We also plan to add new reference and pedagogical material. We have already started providing regularly updated, comprehensive bibliographies to the ESP.ORG site.

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This is a must read book for anyone with an interest in invasion biology. The full title of the book lays out the author's premise — The New Wild: Why Invasive Species Will Be Nature's Salvation. Not only is species movement not bad for ecosystems, it is the way that ecosystems respond to perturbation — it is the way ecosystems heal. Even if you are one of those who is absolutely convinced that invasive species are actually "a blight, pollution, an epidemic, or a cancer on nature", you should read this book to clarify your own thinking. True scientific understanding never comes from just interacting with those with whom you already agree. R. Robbins

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Papers in Classical Genetics

The ESP began as an effort to share a handful of key papers from the early days of classical genetics. Now the collection has grown to include hundreds of papers, in full-text format.

Digital Books

Along with papers on classical genetics, ESP offers a collection of full-text digital books, including many works by Darwin and even a collection of poetry — Chicago Poems by Carl Sandburg.

Timelines

ESP now offers a large collection of user-selected side-by-side timelines (e.g., all science vs. all other categories, or arts and culture vs. world history), designed to provide a comparative context for appreciating world events.

Biographies

Biographical information about many key scientists (e.g., Walter Sutton).

Selected Bibliographies

Bibliographies on several topics of potential interest to the ESP community are automatically maintained and generated on the ESP site.

ESP Picks from Around the Web (updated 28 JUL 2024 )