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Bibliography on: Biofilm

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ESP: PubMed Auto Bibliography 31 Jan 2026 at 01:41 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: 2026-01-30
CmpDate: 2026-01-30

Xie F, Jiang L, Lu Y, et al (2026)

Self-healing quaternized chitosan-phenylboronic hydrogel with ceria nanozymes and stem-cell exosomes simultaneously eradicates MRSA biofilm and regenerates diabetic wounds.

Carbohydrate polymers, 377:124882.

Diabetic wounds represent a major clinical challenge due to their susceptibility to bacterial biofilm infections, persistent oxidative stress, and impaired tissue regeneration. Current therapeutic approaches typically address these pathological factors individually, limiting their overall efficacy in achieving complete wound closure. There is thus an urgent need for integrated platforms capable of simultaneously targeting multiple barriers to healing. Here we show that a self-healing hydrogel composed of quaternized chitosan-phenylboronic acid (QCSP), ceria nanoparticles (CeNPs), and embryonic stem cell-derived exosomes (ESC-Exo) effectively eradicates methicillin-resistant Staphylococcus aureus (MRSA) biofilms, scavenges reactive oxygen species, and promotes tissue regeneration in diabetic mice. The QCSP matrix provides inherent antibacterial activity and injectable, self-healing properties, while CeNPs function as catalytic antioxidants through reversible Ce[3+]/Ce[4+] redox cycling. Incorporation of ESC-Exo further enhances angiogenesis and re-epithelialization. In an MRSA-infected diabetic wound model, this multifunctional hydrogel achieves near-complete wound closure within 12 days alongside significant biofilm clearance and collagen deposition. This work demonstrates that integrating natural polymer-based hydrogels with nanozymes and bioactive exosomes offers a promising strategy for managing complex chronic wounds.

RevDate: 2026-01-30

Chourashi R, Weiner JM, Hoang T-M, et al (2026)

The Pseudomonas aeruginosa PrrF sRNAs and PqsA promote biofilm formation at body temperature.

Journal of bacteriology [Epub ahead of print].

Pseudomonas aeruginosa is a gram-negative opportunistic pathogen that causes both acute and chronic infections in vulnerable populations. Treatment of P. aeruginosa infections is increasingly challenging due to multi-drug resistance, and biofilm formation during infection further increases antibiotic tolerance. Iron, which is sequestered by the host innate immune system, is also a key nutrient that is required for P. aeruginosa biofilm formation. The iron-responsive PrrF small regulatory RNAs (sRNAs) are key to P. aeruginosa's iron starvation response, promote the production of the Pseudomonas quinolone signal (PQS) quorum sensing molecule, and are required for virulence in murine lung infection. Prior work showed that the PrrF sRNAs are dispensable for biofilm formation; however, these studies were performed using flow-cell biofilms grown at room temperature. Here, we demonstrate a temperature dependency for PrrF in P. aeruginosa biofilm formation: the genes for these sRNAs are required for optimal biofilm formation at 37°C but not 25°C. We further show that a ∆pqsA mutant, which lacks production of PQS and related metabolites, phenocopies the ∆prrF mutant. These studies demonstrate the importance of the PrrF sRNAs in P. aeruginosa biofilm formation at body temperature and reveal a previously underappreciated role of temperature in iron homeostasis and P. aeruginosa biofilm physiology.IMPORTANCEBiofilm formation is a critical virulence trait for many microbial pathogens that confers tolerance to the host immune system and antimicrobials. Pseudomonas aeruginosa is an opportunistic pathogen that forms biofilms resulting in treatment failure. Iron is a known requirement for P. aeruginosa biofilm formation, yet the precise role of iron in biofilm physiology remains unclear. Here, we show that temperature alters the requirement for the PrrF small regulatory RNAs, key components of P. aeruginosa's iron starvation response, for biofilm formation. Specifically, PrrF is required for the optimal formation of flow-cell biofilms at 37°C but not at 25°C, yet most flow-cell biofilm studies are conducted at 25°C. These results demonstrate a previously underappreciated role of temperature in P. aeruginosa biofilm physiology.

RevDate: 2026-01-30

López-Ramos RP, Merino L, Angarita-Díaz MDP, et al (2026)

Streptococcus dentisani and Streptococcus mutans in dental biofilm of preschoolers with and without early childhood caries: a cross-sectional study.

European archives of paediatric dentistry : official journal of the European Academy of Paediatric Dentistry [Epub ahead of print].

AIM: To quantify Streptococcus dentisani and Streptococcus mutans in the dental biofilms of preschoolers with and without early childhood caries (ECC) and to assess their relationships with ECC-associated factors.

METHODS: A cross-sectional study involving 204 dental biofilm samples from children aged 3 to 5 years was conducted. ECC was diagnosed according to the International Caries Detection and Assessment System (ICDAS II) criteria. DNA was extracted from the dental biofilm samples, and S. dentisani and S. mutans were quantified via quantitative polymerase chain reaction (qPCR). Additional data were collected on oral hygiene status, salivary pH, cariogenic diet, and oral hygiene habits. Multivariate linear regression was employed to evaluate the relationships between ECC and the concentrations of S. dentisani and S. mutans (expressed in CFU/ng DNA), adjusting for confounding variables.

RESULTS: The mean concentration of S. dentisani in children with ECC was 0.52 log10 CFU/ng DNA lower than that in caries-free children after adjustment for confounders. Frequent consumption of sweets was associated with a 0.65 log10 CFU/ng DNA reduction in S. dentisani levels. Conversely, children with poor oral hygiene had significantly higher concentrations of S. mutans (2.39 log10 CFU/ng DNA).

CONCLUSION: S. dentisani was more abundant in the caries-free biofilm dental samples of children, whereas S. mutans predominated in those with ECC. These findings indicate that both bacteria may play a role in distinguishing between oral health and disease.

RevDate: 2026-01-30
CmpDate: 2026-01-30

Gaayathiri Devi E, MK Nisha (2026)

In silico analysis of Barleria cuspidata compounds against Streptococcus mutans biofilm-associated proteins.

In silico pharmacology, 14(1):45.

UNLABELLED: Dental caries is a prevalent chronic infection caused by tooth-adherent cariogenic bacteria, mainly Streptococcus mutans, which demineralize tooth structure and lead to plaque formation. The present study evaluated the potential of Barleria cuspidata leaf extract (BCLE) to combat tooth decay by investigating its effects on S. mutans, a major contributor to dental caries, using both in vitro and in silico approaches. BCLE strongly inhibited the growth of S. mutans, showing a zone of inhibition of 17.4 mm at 150 µ g/mL, with a minimum inhibitory concentration (MIC) of 1 mg/mL. At twice the MIC (2 mg/mL), it exhibited bactericidal effects, prevented acid production, reduced cell surface hydrophobicity, and inhibited biofilm formation. Thirty-six major compounds revealed from Gas chromatography-mass spectrometry results of BCLE were subjected to molecular docking with the receptors, dextranase, N-terminal, and central regions comprising the third A-repeat through the first P-repeat (A3VP1) of antigen I/II, glucan binding protein C, deoxycytidylate deaminase, and dextran glucosidase that coordinates with the demineralization of tooth structure and plaque formation. Out of thirty-six compounds docked, the top fourteen showed no violations for the drug-likeness feature except monoethylhexylphthalate, pentadecanoic acid, and 3-hydroxy carbofuran phenol. Among them, Octadecanedioic acid represented the highest inhibition with deoxycytidylate deaminase (SmdCD) (PDB ID: 5C2O), and the complex, further analyzed for molecular dynamic simulation for 100ns, was found to be stable from 60-100ns with strong ionic and hydrogen bond interactions. Thus, the study suggested that the anti-cariogenic effect of BCLE would be beneficial in exploring the co-existence of plant extract and inventing novel herbal medicines to enhance caries protection.

SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40203-025-00529-9.

RevDate: 2026-01-29

Shahadat MN, Siddique AB, Ahmed S, et al (2026)

High prevalence of class 1 integron, biofilm formation, and antimicrobial resistance profiles of Escherichia coli isolated from cattle, water, and soil in Bangladesh.

BMC microbiology pii:10.1186/s12866-026-04786-2 [Epub ahead of print].

BACKGROUND: Antimicrobial resistance (AMR) is a global threat. Escherichia coli is an important reservoir of resistance genes, and the coexistence of mcr with class 1 integron (intI1) is alarming, mcr confers resistance to colistin, a last-resort antibiotic, while intI1 often carries multiple transferable resistance determinants. Although colistin use in livestock is banned in Bangladesh, data on colistin-resistant E. coli in food animals, particularly cattle, remain scarce. This study investigated multidrug-resistance patterns, biofilm formation, and the prevalence of intI1 and its association with mcr and other resistance determinants in E. coli from Bangladeshi cattle.

METHODS: A total of 254 samples (feces, rectal swabs, soil, and water) were collected from cattle farms across three divisions of Bangladesh (Dhaka, Sylhet, and Barisal). E. coli isolates were identified using culture methods and confirmed with the VITEK-2 system and PCR. Antimicrobial susceptibility testing was performed using VITEK-2 system following CLSI guidelines. The presence of class 1 integron and mcr (mcr-1 to mcr-5) genes was detected by PCR. Biofilm formation was assessed using the crystal violet assay. Statistical analysis was conducted in R using Chi-square exact test, with significance set at p < 0.05.

RESULTS: E. coli was detected in 76.4% of samples, with the highest prevalence in feces (86.8%). Antimicrobial testing revealed complete sensitivity to several antibiotics, but resistance occurred to cefuroxime (33%), ciprofloxacin (26.8%), and amoxicillin-clavulanic acid (22.2%), with all isolates showing intermediate response to colistin. Overall, 29.4% of isolates were MDR, though no XDR or PDR were detected. Class 1 integron was present in 52.6% and the mcr-1 gene in 21.7%, both significantly associated with MDR (p < 0.001). Water isolates showed the highest proportion of strong biofilm producers (25.5%).

CONCLUSION: This study reveals a high prevalence of class 1 integron and the mcr-1 gene in MDR E. coli from food animals in Bangladesh, highlighting their role in resistance dissemination and the public health risk of colistin resistance. The strong association of integron with MDR and mcr-1 underscores the need for prudent antibiotic use, routine surveillance, and stronger antimicrobial stewardship in livestock to limit the spread of resistance to humans.

RevDate: 2026-01-29
CmpDate: 2026-01-29

Bogachev MI, Baranov PS, Sinitca AM, et al (2026)

Non-contact identification of opportunistic pathogens in mixed biofilm contaminations by hyperspectral imaging.

Analytica chimica acta, 1388:345098.

BACKGROUND: Biofilms are present on almost all surfaces in households, healthcare and medical equipment, foods, industrial and water supply systems, and often contain opportunistic pathogens that represent one of the key public health hazards. The highest risks are imposed by ESKAPEE pathogens, as well as mixed bacterial-fungal communities often exhibiting multiple drug resistance, this way challenging public healthcare.

RESULTS: Here we show how recent developments in hyperspectral imaging technology, complemented by advanced image analysis and machine learning methods, create a unique framework for the potential design of non-contact monitoring systems operating at the macroscale. We could successfully identify five key pathogenic bacteria and a common pathogenic yeast, C. albicans, that frequently occur on surfaces in monospecies and mixed biofilms consisting of combinations of various strains using hyperspectral imaging in the visible, near-infrared, and short-wave infrared spectral bands. Our results indicate that the above pathogenic species could be identified in monocultural biofilms with 95-99.5 % accuracy, while in more frequently occurring mixed biofilms obtained by combining different microorganisms, the accuracy ranges from 90 to 92 % for gram-negative E. coli, K. pneumoniae, and P. aeruginosa to 96-99 % for fungi and gram-positive E. faecalis and S. aureus, respectively, under in vitro conditions.

SIGNIFICANCE: Based on our results, we believe that hyperspectral imaging represents a promising and highly efficient technology for the rapid, regular, non-contact monitoring of various equipment and surfaces to detect bacterial and fungal pathogens in situ.

RevDate: 2026-01-29

Diehl A, Lindemann F, Cremer N, et al (2026)

Conservation and specificity in Bacillus biofilm dynamics: on structure and function of B. cereus Camelysins.

Journal of molecular biology pii:S0022-2836(26)00034-3 [Epub ahead of print].

The B. cereus family comprises members highly pathogenic for mammals or insects, with B. anthracis and B. thuringiensis respectively as notable examples. The biofilm operon of these bacteria encodes two TasA-like proteins, the 60% identical Camelysins CalY1 and CalY2. In this study, we observed that at neutral pH CalY2 alone polymerizes readily into filaments, whereas CalY1 forms a polydispersed mixture of oligomers without filament formation. However, at basic or acidic pH CalY1 also modestly polymerizes. CalY2 polymerization into filaments involves ß-sheet remodeling via donor strand complementation, as demonstrated here by a combination of NMR and AlphaFold studies. In contrast to TasA of B. subtilis, this process is spontaneous and does not require initiation by a TapA homolog. NMR studies show that the functionally relevant region (β1-β2-β3) of the CalY2 monomer structure closely resembles that of B. subtilis TasA, and differs from AlphaFold models. A survey of AlphaFold 2 predictions on 12 homologous B. cereus group Camelysins yielded only four correctly predicted β1-β2-β3 segments, which decreased to one when using AlphaFold 3. Since crucial residues in the protomer contact region are conserved among TasA-like proteins, we investigated whether family members of different species could form mixed filaments. NMR revealed features in CalY2 filaments that are structurally conserved with TasA filaments but sequentially different, promoting specificity. These interactions and differences, respectively, involve the C-terminus and the beginning of β3, which most likely hinder joint TasA and CalY1 copolymerization. A protease activity could not be observed for the heterologously expressed B. cereus Camelysins. SIGNIFICANCE: The B. cereus group includes extremely harmful and surprisingly benign bacterial strains. The Anthrax-toxin-producing B. anthracis is one of the most toxic bacterial threats to man, whereas B. thuringiensis toxin is used as a biological insecticide. Other B. cereus strains pose problems in food production and medical implant usage. These bacteria can exist as biofilms allowing them to survive and proliferate, an essential feature of which are protein filaments. Here we characterize the B. cereus Camelysins CalY1 and CalY2 and compare their structure and filament formation with B. subtilis filaments to understand principles determining patterns of conservation and specificity. This investigation provides the basis for developing novel means to suppress or enhance biofilms with potential benefits for plant protection.

RevDate: 2026-01-29

Li W, Li J, Wu Y, et al (2026)

Artificial regulation of aerobic and anaerobic layers interface enhanced efficient nitrogen removal by weaving insulating grid and conductive carbon fiber in membrane aerated biofilm reactor.

Bioresource technology pii:S0960-8524(26)00155-0 [Epub ahead of print].

Artificial regulation of aerobic and anaerobic biofilm thickness is crucial for enhancing nitrogen removal efficiency of the membrane aerated biofilm reactor (MABR). In this study, conductive aeration membrane modules were fabricated by physical weaving technology to couple MABR with microbial electrochemistry for efficient nitrogen removal. Insulating grids of different thickness and conductive carbon fibers were woven onto the aeration membrane to form aerobic and anaerobic layers. When the total biofilm thickness reached 254 μm (150 μm aerobic layer and 104 μm anaerobic layer), the TN removal efficiency (89.49 ± 2.89 %) was optimal. 16S rRNA gene sequencing and metagenomics analysis confirmed that the aerobic and anaerobic layers in the biofilm were completely separated, but there was a synergistic effect in nitrogen removal. The composite cathode structure provides a mechanism for efficient spatial coupling between the aerobic and anaerobic layers, establishing a basis for regulating biofilm stratification.

RevDate: 2026-01-29

Soares LGP, Sérgio AFA, da Silva APLT, et al (2026)

Er:YAG (λ2940nm) microablation of supragingival biofilm in patients with fixed orthodontic appliances.

Journal of photochemistry and photobiology. B, Biology, 276:113373 pii:S1011-1344(26)00020-5 [Epub ahead of print].

The objective of the study was to evaluate the efficacy of the Er:YAG laser in controlling supragingival biofilm in patients wearing fixed orthodontic appliances. In this randomized, single-session, pre-post intervention study, the sample consisted of 18 individuals undergoing orthodontic treatment at the Prof. José Édimo Soares Martins Center for Orthodontics and Facial Orthopedics, FOUFBA. The Er:YAG laser (λ2940 nm, 0.8 W, 20 Hz, ED = 0.16 J/cm[2], t = 30s) was applied to the cervical region of the right mandibular lateral incisor, at an average distance of 10 mm from the tooth surface. The collections occurred before the intervention (Control Group) and after irradiation with Er:YAG (Laser Group). The samples were inoculated in Petri dishes for visual counting of colony-forming units (CFU). After tabulation and logarithmic transformation of the data obtained, the ANOVA test (General Linear Model) was applied to verify the existence of a significant difference between the groups. Results showed that the logarithmic means of the Control and Laser Groups' CFU count were 5.08 ± 0.71 and 3.04 ± 0.88, respectively. The group comparison showed a significant decrease (ANOVA, F = 58.43; p < 0.001), with a 99% reduction in CFU. In conclusion, Er:YAG laser microablation quickly reduces biofilm in orthodontic patients, offering a promising adjunct to conventional hygiene.

RevDate: 2026-01-29

K V, CT Wang (2026)

Influence of synthesis temperature of eggshell-derived hydroxyapatite on biofilm formation and microbial fuel cell performance.

Bioelectrochemistry (Amsterdam, Netherlands), 170:109235 pii:S1567-5394(26)00021-6 [Epub ahead of print].

Microbial fuel cells (MFCs) enable simultaneous wastewater treatment and bioelectricity generation, but their performance is often constrained by poor bacterial adhesion and slow anode electron transfer. Hydroxyapatite (HA) can address these limitations; however, most studies rely on commercial HA and rarely examine biowaste-derived sources or synthesis-route effects. In this study, eggshell-derived HA was synthesized via room-temperature precipitation (CHP) and hydrothermal treatment at 250 °C for 3 h (CHH), then blended with carbon to fabricate composite anodes. Dual-chamber MFCs inoculated with Shewanella putrefaciens were evaluated using electrochemical analyses (CV, EIS, polarization) and biofilm characterization (CFU counts, crystal violet staining, SEM). CHH achieved a peak power density of 0.164 W m[-2], approximately 167% higher than bare carbon and 23-33% higher than carbon and CHP. CHP exhibited slightly lower peak power but superior sustained output over a wider current-density range, attributed to its low-crystallinity structure and rapid early colonization. The results demonstrate that HA nanostructure, governed by synthesis route, directly influences biofilm formation and electron transfer. Overall, eggshell-derived HA anodes significantly enhance MFC performance, establishing a clear synthesis-nanostructure-biofilm-performance relationship.

RevDate: 2026-01-29

Brandquist ND, T Kielian (2026)

Differential sensitivity of leukocyte populations to Staphylococcus aureus biofilm.

Infection and immunity [Epub ahead of print].

Staphylococcus aureus is a leading cause of prosthetic joint infection (PJI) typified by biofilm formation. Anti-inflammatory granulocytic myeloid-derived suppressor cells (G-MDSCs) represent the main leukocyte population in a mouse model of S. aureus PJI, followed by neutrophils (PMNs), and macrophages (Mφs), which is also seen during human PJI. Defining how each leukocyte population responds to S. aureus biofilm vs planktonic bacteria could have important implications for how S. aureus evades immune detection to facilitate biofilm persistence. This study compared the kinetics of leukocyte death and relationship to mitochondrial ROS (mtROS) production following exposure to planktonic S. aureus or biofilm. Mφs were exquisitely sensitive to S. aureus biofilm with toxicity observed within 15 min following biofilm co-culture, whereas G-MDSCs and PMNs were more resilient, with appreciable survival out to 6 h. In contrast, G-MDSC viability was significantly decreased after extended exposure to planktonic S. aureus compared to PMNs and Mφs. Although leukocyte death coincided with increased mtROS production across all leukocyte populations, inhibiting mtROS had no impact on leukocyte survival following biofilm co-culture, suggesting alternative cell death triggers. Caspase-1-dependent pyroptosis was observed in PMNs, whereas Mφs and G-MDSCs were targeted by necrosis since an inhibitor of H2O2-induced necrosis improved cell survival of both populations, whereas programmed cell death inhibitors had no effect. These findings may account, in part, for the abundance of G-MDSCs and PMNs, but not Mφs, during PJI based on differential susceptibility to biofilm-induced cytotoxicity.

RevDate: 2026-01-29
CmpDate: 2026-01-29

Er H, İ Kaleli (2026)

[Investigation of Antibiotic Resistance Profiles, Molecular Epidemiology and Biofilm Formation in Corynebacterium striatum Isolated from Clinical Samples].

Mikrobiyoloji bulteni, 60(1):1-13.

This study aimed to evaluate the antibiotic resistance profiles, molecular epidemiology, and biofilm formation of Corynebacterium striatum isolated from clinical samples in our hospital. A total of 132 C.striatum isolates were included in the study. Antimicrobial susceptibility testing was performed using the disk diffusion method in accordance with the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Resistance genes were determined using polymerase chain reaction. Biofilm formation was investigated using the microtiter plate method. Clonal relationships in isolates were examined using the Pulsed Field Gel Electrophoresis (PFGE) method. All isolates were found to be susceptible to vancomycin and linezolid. Resistance rates among the isolates were quite high, with resistance to ciprofloxacin, penicillin, clindamycin, rifampin, tetracycline, gentamicin and erythromycin observed in 100.0%, 98.5%, 97.0%, 99.2%, 100.0%, 90.2%, and 74.2% of the isolates, respectively. bla/ampC, ermX, aac(3)-XI, aphA1, gyrA, and tetA genes were detected as 99.2%, 96.2%, 93.2%, 91.7%, 100.0% and 43.8%, respectively. In isolates positive for the aphA1 and aac(3)-XI genes, the gentamicin resistance rate and in isolates positive for the ermX gene, the clindamycin and erythromycin resistance rates were found as significantly higher (p< 0.05). Biofim formation was detected in 28% of the isolates. The similarity ratio of the isolates was determined to be 85%. The four main clusters, A, B, C, and D showed 32 different PFGE patterns. The clustering rate was determined to be 96.0%. In conclusion, the high rates of phenotypic and genotypic antimicrobial resistance among C.striatum strains in our hospital are quite remarkable.

RevDate: 2026-01-29
CmpDate: 2026-01-29

Luo X, Wang S, Yang Y, et al (2025)

Engineered Pseudomonas aeruginosa phages with quorum-quenching enzyme or depolymerase for inhibition of biofilm formation.

Frontiers in microbiology, 16:1752980.

Pseudomonas aeruginosa is a major cause of healthcare-associated infections and a significant threat to global health, primarily due to its ability to form biofilms that protect it from host immune responses and block antibiotic efficacy. While bacteriophages (phages) are emerging as potential antimicrobial agents, their effectiveness is often limited by these bacterial biofilms. This study aimed to enhance the biofilm-disrupting capabilities of phages through genetic engineering. First, we validated the in vitro biofilm-inhibitory effects of two enzymes: the quorum-quenching lactonase (Aiia) and a phage-derived depolymerase (DP). To demonstrate their potential, we then used CRISPR-Cas9 to engineer the P. aeruginosa phage PaGZ-1 to express these biofilm-disrupting genes. The resulting engineered phages demonstrated superior inhibition of biofilm formation compared to the wild-type phage. Notably, the PaGZ-1-Aiia variant showed significant promise in both inhibiting biofilm formation and disrupting established biofilms. Our findings provide a straightforward method for introducing exogenous genes into non-model P. aeruginosa phage genomes, offering a novel and potentially effective strategy for combating drug-resistant, biofilm-forming infections.

RevDate: 2026-01-29

Zhao J, Huang S, Yang Y, et al (2026)

Dental plaque biofilm-targeting composite nanomaterials: advances and outlook.

Biomaterials science [Epub ahead of print].

The disruption of oral microbial homeostasis is a major cause of periodontal disease, and the formation of pathogenic plaque biofilms is a key driver of disease progression. Extracellular polymeric substances (EPS) within dental plaque biofilms provide structural support and a protective barrier, rendering these biofilms markedly resistant to conventional antimicrobial strategies. Owing to their favorable physicochemical properties, biocompatibility, and multifunctionality, nanomaterials have attracted widespread attention as potential drug-delivery platforms and therapeutic agents targeting EPS across inorganic, organic, natural-product-derived, and composite systems. This review concentrates on recent advances in the use of nanomaterials, especially nanozymes, for degrading the EPS matrix and treating dental plaque biofilms. It explicates mechanisms by which nanomaterials act, including inhibition of EPS production and adhesion, degradation of polysaccharides and proteins, targeting of extracellular DNA (eDNA), and exploitation of negative surface charge to disrupt biofilm integrity; and we also explored the potential of polypeptide-folded artificial enzymes as multifunctional nanocarriers in combination with other therapeutic modalities. Collectively, these studies furnish a theoretical rationale and technical support for the development of novel, effective antimicrobial strategies and may open new avenues for periodontal therapy. The review also summarizes current challenges in the field of nanomaterial-based and EPS-targeted periodontal treatment and discusses possible approaches to address these obstacles.

RevDate: 2026-01-29
CmpDate: 2026-01-29

Salman , Yasmin A, Rahatuzzaman , et al (2026)

Bacterial Diversity in Fish Farms: Relation to Biofilm Formation, Antibiotic Resistance, and Heavy Metal Tolerance.

Journal of basic microbiology, 66(1):e70150.

The emergence of multidrug-resistant (MDR) bacteria is facilitated by the excessive and inappropriate use of antibiotics in aquaculture. This study assessed antibiotic resistance profiles and heavy metal responses of bacteria isolated on Thiosulfate Citrate Bile Salts Sucrose (TCBS) agar from six sample types across three fish farms, yielding 51 isolates belonging to nine genera and 12 bacterial classes, with Staphylococcus being the most predominant genus. Although they appeared as Gram-positive on TCBS agar, 16S rRNA sequencing confirmed their taxonomic identity, indicating that TCBS selectivity requires reevaluation. Half of the isolates were multidrug-resistant (50.98%), and MDR and MAR index >0.2 were more frequent in Gram-negative (71%) than in Gram-positive isolates (33%). The most prevalent resistance determinants were tetM (62.7%) and tetA (54.9%), while only one isolate carried a carbapenemase gene. Biofilm formation was observed in 80.4% of isolates. Heavy metal susceptibility followed the order Cd[2+] > Cr[6+] > Zn[2+] > Pb[2+], and co-exposure to Cd[2+], Zn[2+], and Cr[6+] (40 ppm) significantly increased resistance to imipenem. These findings indicate that aquaculture environments may act as reservoirs for co-resistant pathogens, posing potential risks to food safety and public health.

RevDate: 2026-01-28

Klesiewicz K, Mrowiec P, Kania K, et al (2026)

Vancomycin-resistant enterococci in healthcare settings: clonal analysis, resistance profiles, and biofilm formation of strains isolated from hospitalized patients.

Folia microbiologica [Epub ahead of print].

Multidrug-resistant bacteria, including vancomycin-resistant Enterococci (VRE), are a significant public health threat. This study aimed to perform molecular characterization of E. faecium and E. faecalis isolates with respect to glycopeptide and phenotypic resistance, and clonal relatedness. A total of 45 isolates (41 E. faecium, 4 E. faecalis) were obtained from clinical specimens collected at the University Hospital in Kraków, Poland. Isolates were screened on chromogenic media, identified by Matrix-Assisted Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) and tested for antimicrobial susceptibility and the presence of vanA/vanB genes. Biofilm formation was assessed on culture media, and clonal relationships were determined using PFGE. Among the isolates, 86.7% harbored vanA and 13.3% vanB genes. E. faecium remained resistant mainly to ampicillin and teicoplanin, but susceptible to tigecycline and linezolid. E. faecalis showed partial susceptibility to ampicillin, tigecycline and linezolid, but frequent resistance to teicoplanin and reduced susceptibility to imipenem. Biofilm assessment revealed that 88.9% of isolates produced high biofilm levels. PFGE analysis identified several clonal groups among Enterococcus faecium, with clone A being the most prevalent (9 strains). The predominance of clonal strains and their robust biofilm production underscore the dissemination potential of VRE in hospital settings. High levels of antibiotic resistance highlight the limited therapeutic options available. Comprehensive preventive and control measures are essential to mitigate transmission of multidrug-resistant pathogens in healthcare environments. These findings provide recent epidemiological data on VRE circulation and highlight the clinical relevance of a dominant, biofilm-forming clonal lineage in a tertiary-care setting.

RevDate: 2026-01-28

Mohd Daud IS, Mahmud Ab Rashid NK, Palmer J, et al (2026)

From extraction to application: Nanoemulsified lemongrass oil for biofilm and spore control in food preservation.

International journal of food microbiology, 450:111654 pii:S0168-1605(26)00033-4 [Epub ahead of print].

Bacillus cereus is a spore-forming, toxin-producing pathogen that poses a persistent threat to global food safety due to its resistance to heat, disinfectants, and its ability to form biofilms. This review highlights the antimicrobial potential of lemongrass essential oil (LEO) and its major compound, citral, from traditional use to its modern application through nanoemulsion systems. It critically examines how extraction methods affect citral content and bioactivity, and how nanoemulsification enhances LEO's stability, solubility, and efficacy against B. cereus spores and biofilms. Applications include dairy, meat, and fresh produce preservation, where LEO-based coatings, packaging, and sanitizers offer clean-label alternatives to synthetic preservatives. The review also explores regulatory and safety concerns and identifies gaps in sensory effects, long-term stability, and dosing optimization. Overall, citral-rich LEO nanoemulsions represent a promising, sustainable strategy to improve microbial safety and shelf life in food systems affected by B. cereus.

RevDate: 2026-01-28

Bhattrai S, Sun Z, Jenkins M, et al (2026)

Biofilm formation by clinical Clostridium perfringens isolates and its suppression by thymol.

Poultry science, 105(4):106409 pii:S0032-5791(26)00039-8 [Epub ahead of print].

Necrotic enteritis (NE) caused by Clostridium perfringens imposes major health and economic losses in broiler production, especially with coccidiosis co-infection. Beyond toxin secretion, C. perfringens forms biofilms that enhance persistence and reduce treatment efficacy. Thymol, a phenol from thyme, has broad antimicrobial and antibiofilm activities, but its effects on C. perfringens biofilms are not well defined. We profiled 23 clinical isolates, genotyped them (all cpa[+], most cpβ2[+]; eight netB[+]; tpeL detected only in LLY_TpeL17), quantified biofilm biomass by 0.1% crystal violet staining (OD570) with and without 1% glucose, and tested thymol (6.25-1600 µg/mL) in a microplate model for effects on planktonic growth (OD590) and biofilm formation. Biofilm capacity varied widely, and glucose increased baseline biomass. Thymol inhibited planktonic growth and biofilm biomass in a dose-dependent manner, with the minimum inhibitory concentration (MIC) values of approximately 100 µg/mL in glucose-deprived medium and 200 µg/mL in 1% glucose-supplemented medium, where biofilm formation was significantly reduced at sub-MIC concentrations (25-50 µg/mL) under both conditions. In mature 72-h biofilms from high-biofilm producers, a 3-h thymol exposure reduced metabolic activity (resazurin RFU) and biomass, with strong effects at 50-100 µg/mL and near-baseline signals at ≥200 µg/mL. These findings reveal substantial isolate-to-isolate variability and support thymol as a promising natural antimicrobial and antibiofilm agent for NE control in poultry.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Av VR, Dubal ZB, O R VK, et al (2026)

Enterotoxin and biofilm producing Staphylococcus aureus and MRSA isolates from animal source foods sold in Assam.

Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology], 57(1):45.

Animal-derived foods (ADF) are carriers of toxin-producing multidrug-resistant (MDR) S. aureus strains, posing a global food safety risk. We evaluated the toxin and biofilm production capabilities of S. aureus isolates from ADF marketed in Assam, India. Of the 138 staphylococcal isolates, 29 (21.01%) were identified as S. aureus, mostly isolated from raw milk. Resistance to chloramphenicol (13.79%), erythromycin (68.96%), penicillin (93.10%), enrofloxacin (20.68%), tetracycline (55.17%), trimethoprim-sulfamethoxazole (20.68%), linezolid (6.89%), cefoxitin (55.17%), and oxacillin (48.27%) was noted. Approximately 82.75% isolates were MDR, whereas 27.58% carried mecA gene, indicating methicillin-resistant S. aureus. PCR toxinotyping revealed pvl (20.69%), sea (37.93%), and sed (17%) genes. Additionally, 6.89% isolates harbored seb, sei, and tst genes; all lacked eta, etb, see, seg genes. A significant difference (P < 0.05) was observed in sea and sei genes across food sources. Biofilm-forming genes were detected as icaA (65.51%), icaB (34%), icaC (48.27%), icaD (27.58%), clfA (51.72%), clfB and fnbA (44.82%). At least one biofilm-associated gene was found in 72.41% of isolates, while two or more genes were present in 80.95%. Approximately 87.5% of mecA-positive isolates contained at least one biofilm-associated gene. A significant difference (P < 0.05) was noted in icaA, icaD, clfB, and fnbA across the different ADF sources.

RevDate: 2026-01-28

Adhikary R, Poddar S, Patel D, et al (2026)

Draft genomes of four multidrug-resistant (MDR) Gammaproteobacteria from biofilm on hemodialysis catheters in Gujarat, India.

Microbiology resource announcements [Epub ahead of print].

Four Gram-negative bacteria, viz. Pseudomonas aeruginosa HL_CHRF_S30, Klebsiella quasipneumoniae HL_CHRU_S36A, Enterobacter bugandensis HL_CHRU_S49, and Acinetobacter haemolyticus HL_CHRU_S74 were isolated from the biofilm of the catheter tip of 152 renal failure patients. Multiple antibiotic-resistant gene cassettes were predicted by whole-genome analysis of these Gammaproteobacteria to develop antibiotic resistance.

RevDate: 2026-01-28

Diarrassouba A, Rekiki A, Loubière C, et al (2026)

Medical Fabrics with Non-Antibiotic, Supramolecular Antimicrobial Coatings: A Preventive Approach to Combat Biofilm Formation and Bacterial Dissemination.

Advanced healthcare materials [Epub ahead of print].

Infections caused by bacterial colonization and biofilm formation on wounds and dressings present critical challenges to wound care, often impeding healing. Here, we report an antibiotic-free preventive strategy based on medical fabric coated with supramolecular antimicrobial assemblies. Using layer-by-layer dip coating technique, we functionalized medical fabric with polyarginine (PAR30) and hyaluronic acid (HA144) polymers, biopolymers that synergistically exhibited intrinsic antimicrobial activity. Coatings deposition and structural integrity were validated by confocal microscopy and ATR-FTIR spectroscopy. Antibacterial performance was assessed using the AATCC100 standard test method, showed strong efficacy against both Gram-negative and Gram-positive clinical pathogens. In vivo wound infection models, employing bioluminescent methicillin-resistant Staphylococcus aureus (MRSA), were used to evaluate biofilm prevention. Coated and uncoated fabrics were either pre-inoculated with MRSA or applied to pre-infected wounds to assess their antimicrobial and anti-biofilm effects. The coated fabrics showed potent antibacterial activity, achieving ≥6 log-reduction in bacterial load within 24 h compared to uncoated fabrics. Bioluminescence imaging confirmed infection development in wounds covered with uncoated fabrics, while coated fabrics prevented infection with a ≥6 log-reduction in bacterial load on fabrics and a ≥4 log-reduction in wound biopsies. Additionally, coated fabrics inhibited biofilm formation and bacterial proliferation in wound beds inoculated with MRSA. Comprehensive in vitro and in vivo biocompatibility assessments demonstrated the safe profile of the coated fabrics for clinical use. These findings highlight the antimicrobial efficiency of coated fabrics in minimizing bacterial colonization and biofilm formation on wounds and textiles. This safe and effective first-in-class, innovative approach offers a promising preventive strategy against biofilm formation and addresses antimicrobial-resistant strains like MRSA in wound care.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Ravi A, I Pan (2025)

Mitigating gut dysbiosis induced by biofilm-forming pathogens: therapeutic potential of LAB-derived bacteriocins.

Frontiers in microbiology, 16:1721987.

INTRODUCTION: The gut-brain axis plays a critical role in bidirectional communication system connecting intestinal and neurological health. Imbalance in this system, often caused by gut dysbiosis and pathogenic biofilm formation, can result in inflammation, intestinal barrier dysfunction, and microbial imbalance.

METHODS: LAB isolates were screened for antimicrobial and antibiofilm activity against Escherichia coli and Serratia marcescens. The most effective strain, C82, was identified through morphological, biochemical and 16S rDNA sequencing. Bacteriocin production, and stability were assessed and optimized. The functional efficacy of the bacteriocin was tested in a zebrafish larval gut dysbiosis model.

RESULTS: Lactiplantibacillus pentosus C82, confirmed through 16S rDNA sequencing (NCBI GenBank submission ID: SUB14502111, accession number PP860573), demonstrated strong antimicrobial activity, with inhibition zones of 1.2 cm against E. coli and 1.4 cm against S. marcescens. The bacteriocin reduced inflammation and improved gut barrier integrity. It upregulated IL-10, Claudin-5a, ZO-1, Nfe2l2a, and Hmox1a, while downregulating TNF-α, csgD, and bsmA.

DISCUSSION AND CONCLUSION: These results establish L. pentosus C82 bacteriocin as a safe, stable, and potent natural antimicrobial agent with significant antibiofilm, antioxidative, and gut-protective effects. It shows promise as a bio-therapeutic candidate for restoring microbial balance, addressing gut dysbiosis, and influencing the gut-brain axis. However, the study was limited to short-term evaluation in zebrafish larvae, which may not fully represent the complexity of the mammalian gut. Further research involving long-term exposure and higher animal models is necessary to validate its therapeutic potential.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Yu X, Zhang Y, Yao Y, et al (2025)

Biofilm-mediated immune dysregulation in chronic pulmonary diseases: mechanisms and clinical implications.

Frontiers in microbiology, 16:1736384.

Microbial biofilms are increasingly recognized as critical modulators of chronic airway inflammation and immune dysregulation in pulmonary diseases. This review summarizes current evidence on how biofilm formation and persistence alter host immune responses, contributing to the pathogenesis of chronic lung disorders. We first outline the characteristics of respiratory biofilms and the major pathogens involved. We then discuss how biofilms reshape innate and adaptive immunity-impairing pattern recognition receptor signaling, promoting neutrophil extracellular trap (NET) formation, altering macrophage polarization, and skewing T-cell differentiation. These immune alterations sustain low-grade inflammation, tissue remodeling, and immune tolerance, driving disease progression in chronic obstructive pulmonary disease, bronchiectasis, severe asthma, and even lung cancer. We further highlight emerging diagnostic biomarkers and therapeutic approaches targeting biofilm-associated immune pathways, including combined antibiofilm and immunomodulatory strategies. Finally, we identify key knowledge gaps and propose future research directions, emphasizing multi-omics approaches and personalized interventions to better define and target biofilm-driven immune dysregulation in chronic respiratory diseases.

RevDate: 2026-01-28

Juliet R, R Nachimuthu (2025)

Correction: Carbapenem-resistant Klebsiella pneumoniae from clinical infections: a multifactorial analysis of resistance, virulence, and biofilm potential.

Frontiers in cellular and infection microbiology, 15:1762026.

[This corrects the article DOI: 10.3389/fcimb.2025.1712034.].

RevDate: 2026-01-28
CmpDate: 2026-01-28

Małaszczuk M, Pawlak A, P Krzyżek (2025)

Salmonellosis as a One Health-One Biofilm Challenge: Biofilm Formation by Salmonella and Alternative Eradication Strategies in the Post-Antibiotic Era.

Pharmaceuticals (Basel, Switzerland), 19(1): pii:ph19010061.

Non-typhoidal Salmonella (NTS) are globally distributed zoonotic pathogens of major concern within the One Health-One Biofilm framework. Fluoroquinolone-resistant Salmonella strains are included by the World Health Organization (WHO) in the Bacterial Priority Pathogens List as high-risk agents. A key virulence determinant of Salmonella is its ability to form biofilms, which may display multidrug-resistant (MDR) characteristics and contribute to bacterial persistence and treatment failure. Animals, particularly poultry and reptiles, represent important reservoirs of Salmonella, and reptile-associated salmonellosis (RAS) may manifest as extraintestinal infections in humans. In the post-antibiotic era, there is an urgent need to identify effective alternatives to conventional therapies. This review summarizes current knowledge on Salmonella biofilms, with particular attention to their MDR potential, and discusses possible strategies for their prevention and eradication, including specific immunoprophylaxis, bacteriophage therapy, and alternative antimicrobials. The promising antimicrobials include plant-based compounds/extracts, bacteriocins, fatty acids, and synthetic/semi-synthetic substances. The integration of vaccination, phage therapy, and novel anti-biofilm compounds may provide a sustainable alternative to antibiotics in controlling Salmonella infections and aligns with the principles of the One Health approach.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Damar-Çelik D, Mataraci-Kara E, İstanbullu-Tosun A, et al (2025)

Evaluation of the In Vitro Synergistic Activity of Ceftazidime/Avibactam Against Stenotrophomonas maltophilia Strains in Planktonic and Biofilm Cell Cultures.

Pharmaceuticals (Basel, Switzerland), 19(1): pii:ph19010001.

Background/Objectives: Stenotrophomonas maltophilia (SM) is a significant cause of hospital-acquired infections in immunocompromised and critical care patients. This study investigates the impact of combining ceftazidime/avibactam (CZA) with conventional antibiotics on SM obtained from various sources in planktonic and biofilm cell cultures. Methods: Using broth microdilution, the MICs of different antibiotics, including CZA, were determined on 37 SM strains. CZA's bactericidal and synergistic effectiveness were examined through in vitro time-kill curve tests with tigecycline (TGC), chloramphenicol (CHL), levofloxacin (LVX), colistin (CS), and amikacin (AMK). In addition, synergistic activity was investigated against SM biofilm cell cultures, and antibiotic Mutant Prevention Concentrations (MPCs) were tested against SM isolates. Results: Compared to ceftazidime (CAZ), CZA was four times more efficient against 37 SM strains. Unlike TGC and CHL, CS, AMK, and CZA had 2-4 times higher MBCs than MICs. All studied antibiotics were bactericidal at 1× or 4× MIC doses against SM bacteria, except for CZA. The combinations of CZA with LVX and CZA with AMK or CS demonstrated synergistic effects in four out of seven (57%) strains and in three out of seven (43%) strains, respectively, when tested at doses equivalent to the MIC. Moreover, all antibiotic combinations with CZA showed a synergistic effect at dosages four times the MIC. Additionally, CZA and the tested drugs synergistically inhibited SM biofilm formation, and MPC values were 8-16 times the MIC. Conclusions: The results of this study indicate that combining CZA with LVX and CS was more effective against SM strains. These combinations might provide alternatives for treating SM pathogens in both planktonic and biofilm cell cultures.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Wuersching SN, Manghofer D, Stawarczyk B, et al (2026)

Surface Properties of Dental Materials Influence the In Vitro Multi-Species Biofilm Formation.

Polymers, 18(2): pii:polym18020288.

This study examined the association between biofilm growth and surface properties of 3D printed, milled, and conventional materials used for manufacturing fixed dental prostheses. Disc-shaped specimens were produced and finished from five 3D-printing resins (VarseoSmile Crown plus [VSC], NextDent C&B MFH [ND], VarseoSmile Temp [VST], Temp PRINT [TP], P Pro Crown & Bridge [P]), two polymer milling blocks (composite: TetricCAD [TC], PMMA: TelioCAD [TEL]), two conventional polymer materials (Tetric EvoCeram [TEC], Protemp 4 [PT]), and zirconia (ZR). Surface roughness (Ra), wettability, interfacial tension (IFT) and surface topography were examined. Three-day biofilms were grown on the specimens using A. naeslundii, S. gordonii, S. mutans, S. oralis, and S. sanguinis in a multi-species suspension. Biofilms were quantified by crystal violet staining and with a plating and culture method (CFU/mL). Linear regression analysis was computed to demonstrate associations between the surface properties and biofilm growth. The strength of this relationship was quantified by calculating Spearman's ρ. TC exhibited the highest, and TP the lowest IFT. TEC showed the highest Ra, while TEL had the lowest, with significant differences detected particularly between milled and 3D-printed specimens. TP specimens exhibited the highest biofilm mass, while ZR surfaces retained the least. Bacterial viability within the biofilms remained similar across all tested materials. There was a strong negative correlation between total IFT and biofilm mass, and a moderate positive correlation between Ra and CFU/mL. Surface properties are shaped by material composition, microstructure, and manufacturing methods and play a crucial role in biofilm formation on dental restorations.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Risheq S, Venugopal A, Sancho A, et al (2026)

Sustained Release Varnish of Chlorhexidine for Prevention of Biofilm Formation on Non-Absorbable Nasal and Ear Sponges.

Pharmaceutics, 18(1): pii:pharmaceutics18010096.

Background: Non-absorbable polyvinyl alcohol sponges (Merocel) are widely used in otolaryngology for nasal and ear packing but are prone to bacterial colonization and biofilm formation, which may increase infection risk and drive frequent use of systemic antibiotics. Sustained-release drug delivery systems enable prolonged local antiseptic activity at the site of packing while minimizing systemic exposure. Methods: We developed a sustained-release varnish containing chlorhexidine (SRV-CHX) and coated sterile Merocel sponges. Antibacterial, in vitro, activity against Staphylococcus aureus and Pseudomonas aeruginosa was evaluated using kinetic diffusion assays on agar, optical density (OD600) measurements of planktonic cultures, drop plate, ATP-based viability assays, biofilm analysis by MTT metabolic assay, crystal violet bio-mass staining, high-resolution scanning electron microscopy (HR-SEM), and spinning disk confocal microscopy. Results: SRV-CHX-coated sponges produced sustained zones of inhibition on agar plates for up to 37 days against S. aureus and 39 days against P. aeruginosa, far exceeding the usual 3-5 days of clinical sponge use. Planktonic growth was significantly reduced compared with SRV-placebo, and a bactericidal effect persisted for up to 16 days for S. aureus and 5 days for P. aeruginosa before becoming predominantly bacteriostatic. Biofilm formation was markedly inhibited, with suppression of metabolic activity and biomass for at least 33 days for S. aureus and up to 16 days for P. aeruginosa. HR-SEM and confocal imaging confirmed sparse, discontinuous biofilms and predominance of non-viable bacteria on SRV-CHX-coated sponges compared with dense, viable biofilms on the placebo controls. Conclusions: Coating Merocel sponges with SRV-CHX provides prolonged antibacterial and anti-biofilm activity against clinically relevant pathogens. This strategy may reduce dependence on systemic antibiotics and improve infection control in nasal and ear packing applications in otolaryngology.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Dubinenko G, Senkina E, Golovina K, et al (2025)

Tailorable Antibacterial Activity and Biofilm Eradication Properties of Biocompatible α-Hydroxy Acid-Based Deep Eutectic Solvents.

Pharmaceutics, 18(1): pii:pharmaceutics18010016.

Background/Objectives: Deep eutectic solvents (DESs) have recently gained attention for their antimicrobial properties, particularly because they target both planktonic bacteria and biofilms. Among these, DESs based on α-hydroxy acids (αHAs) are of interest due to their inherent antibacterial properties and favorable biocompatibility. However, effects of the αHA molecular structure and hydrogen bonding ability within a DES formulation on biological activity has not yet been thoroughly investigated. Methods: This study systematically investigates DESs formed by combining glycolic acid, lactic acid or tartaric acid with either choline chloride or tetraethylammonium chloride. Results: All DESs demonstrate broad-spectrum antibacterial activity against Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa and effectively inhibit biofilm formation while exhibiting low cytotoxicity toward 3T3-L1 fibroblasts. Conclusions: DES formation enhances antibacterial efficacy while attenuating cytotoxicity compared to the individual components, thereby decoupling bactericidal activity from toxicity. Physicochemical characterization confirms the formation of a eutectic phase and reveals that biological activity is primarily governed by acidity rather than by the specific αHA structure or eutectic strength. These results provide new insights into structure-function relationships in DESs and establish a design strategy for biocompatible, non-cytotoxic antimicrobial agents.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Kaliniak S, Deptuła P, Spałek J, et al (2025)

Ceragenins in Combination with Ivacaftor Prevent the Formation of Biofilm by Bacteria That Cause Rhinosinusitis.

Pharmaceutics, 18(1): pii:pharmaceutics18010001.

Background/Objectives: Ceragenins (CSAs) maintain strong antibacterial activity even in cystic fibrosis (CF) sputum. Ivacaftor (IVA), a CF transmembrane regulator modulator, provides significant clinical benefits in CF therapy. Based on these properties, we hypothesized that the combination of CSAs and IVA, due to their antibacterial and biofilm-penetrating abilities, may also be beneficial in the treatment of chronic rhinosinusitis (CRS), including CRS in CF patients. Notably, the physicochemical properties of biofilms in chronic rhinosinusitis (CRS) resemble those in CF sputum. Methods: We determined the minimal inhibitory and bactericidal concentrations (MIC and MBC) and the fractional inhibitory concentration index (FICI) for ceragenins (CSA-13, CSA-44, CSA-131), ivacaftor (IVA), selected conventional antibiotics, and their combinations against both reference and clinical strains. Bacterial viability within biofilms was also evaluated following exposure to these agents. Atomic force microscopy (AFM) was used to analyze the morphology and nanomechanical properties of Staphylococcus aureus and Pseudomonas aeruginosa. In addition, rheological measurements of Pseudomonas aeruginosa biofilms treated with CSAs combined with IVA were performed using a rotational rheometer. Results: The tested agents demonstrated anti-biofilm activity against bacterial strains associated with CRS development. IVA enhanced the anti-biofilm effects of both CSAs and tested antibiotics. CSAs exhibited low MIC and MBC values, confirming their efficacy against tested pathogens. AFM showed that CSA-44, IVA, vancomycin, and their combinations altered the nanomechanical properties of Pseudomonas aeruginosa and Staphylococcus aureus cells. Interestingly, the addition of IVA induced aggregation of S. aureus cells. CSAs reduced the stiffness of P. aeruginosa biofilms, and co-treatment with IVA resulted in a further decrease in biofilm stiffness. Conclusions: These findings indicate that ceragenins, particularly in combination with ivacaftor, represent a promising therapeutic strategy for challenging chronic infections caused by the studied bacteria. This supports further research aimed at developing new treatment methods for CRS.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Szabóová T, Gregová G, Király J, et al (2026)

Prevalence of Biofilm-Forming and Antibiotic-Resistant Coagulase-Negative Staphylococci Isolated from Hospitalized Patients in an Orthopedic Clinic.

Pathogens (Basel, Switzerland), 15(1): pii:pathogens15010120.

Methicillin-resistant coagulase-negative staphylococci (MRCoNS) are a major cause of infectious diseases, owing to their ability to form biofilms and colonize community and hospital environments. MRCoNS strains were identified using biochemical tests, an MALDI-TOF MS analyzer, and PCR-based 16S rRNA gene confirmation. This study was designed to assess antibiotic resistance and biofilm-forming capacity and to determine the presence of the mecA, mecC, agrA, srtA, icaABCD, bap, fnbAB, and clfAB genes in MRCoNS isolates. From patients undergoing random screening during hospitalization in the Orthopedics Clinic in Slovakia, 28 strains of MRCoNS were identified: S. epidermidis (n = 10), S. hominis (n = 8), S. haemolyticus (n = 4), S. lugdunensis (n = 3), while S. simulans, S. pasteuri, and S. warneri were detected only once. The highest rates of resistance were observed for ampicillin, oxacillin, rifampicin, trimethoprim (100%), and erythromycin (62%). The mecA gene was detected in 12 analyzed isolates. In 12 isolates, MDR, strong efflux pump activity, and strong or moderate biofilm formation were simultaneously detected. Our findings highlight the problems posed by biofilm-forming, resistant CoNS in hospitalized patients and the importance of diagnostics, separation, rapid treatment, and proper hospital hygiene.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Shaikh S, Mekonnen A, Saleem AN, et al (2026)

A Predictive Computational Framework for Staphylococcus aureus Biofilm Growth Stages in Hydrodynamic Conditions.

Pathogens (Basel, Switzerland), 15(1): pii:pathogens15010118.

Biofilms formed by Staphylococcus aureus on medical devices and tissue surfaces are a major contributor to persistent infections due to their resistance to antibiotics. Hydrodynamic forces in physiological and device-associated environments significantly influence biofilm development, yet the dynamics of detachment and regrowth under flow remain poorly quantified. In this study, biofilm surface coverage was measured in microfluidic flow assays across combinations of shear rates and nutrient concentrations. A computational workflow was used to segment biofilm trajectories into three kinetic phases-growth, exodus, and regrowth-based on surface coverage dynamics. Each phase was modeled using parametric functions, and fitted parameters were interpolated across experimental conditions to reconstruct biofilm lifecycles throughout the flow-nutrient conditions. The analysis revealed that intermediate shear rates triggered early detachment events while suppressing subsequent regrowth, whereas lower and higher shear regimes favored biofilm persistence. The resulting model enables quantitative comparison of condition-specific biofilm behaviors and identifies key thresholds in mechanical and nutritional inputs that modulate biofilm stability. These findings establish a phase-resolved framework for studying S. aureus biofilms under hydrodynamic stress and support future development of targeted strategies to control biofilm progression in clinical and engineered systems.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Chen G, Chen J, Wang X, et al (2026)

Fusobacterium nucleatum Enhances Intestinal Adaptation of Vibrio cholerae via Interspecies Biofilm Formation.

Microorganisms, 14(1): pii:microorganisms14010211.

Biofilm formation represents a key survival strategy employed by Vibrio cholerae to adapt to the complex intestinal environment of the host. While most previous studies on V. cholerae biofilms have focused on genetic regulation and monospecies cultures, its ability to form dual-species biofilms with other intestinal pathogens is still poorly understood. In this study, using samples from both cholera patients and healthy individuals, Fusobacterium nucleatum was identified as a bacterium capable of co-aggregating with V. cholerae. Untargeted metabolomic analysis revealed that F. nucleatum-derived metabolites, specifically 6-hypoxanthine, enhance biofilm formation in V. cholerae. Further validation confirmed that these F. nucleatum-derived metabolites upregulate the biofilm-associated regulatory gene vpsT. In an adult mouse model, co-infection with F. nucleatum and V. cholerae significantly enhanced the intestinal adaptability of V. cholerae compared to infection with V. cholerae alone. Together, these findings elucidate the mechanism enabling the co-infection of F. nucleatum and V. cholerae in the host intestine, thereby shedding new light on how other pathogenic bacteria can assist in V. cholerae infection.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Mahapatra S, S Ankri (2025)

The Role of Biofilm-Derived Compounds in Microbial and Protozoan Interactions.

Microorganisms, 14(1): pii:microorganisms14010064.

Biofilms are more than just structural microbial communities. They are dynamic chemical ecosystems that synthesize a range of extracellular compounds involved in functions that extend beyond biofilm architecture. From quorum-sensing molecules like acyl-homoserine lactones (AHLs) to short-chain fatty acids (SCFAs), phenazines, indoles, and reactive sulfur species (RSS), biofilm-derived metabolites can impact the physiology and behavior of microorganisms living in the same ecosystem, including other bacteria and protozoa. It has recently been demonstrated that such molecules may also modulate competition between microbes, promote cooperation, and impact motility, differentiation, or virulence of free-living and parasitic protozoa. This review aims to discuss biofilm compounds that mediate interspecies or interkingdom interactions and their involvement in regulating gut and environmental microbiomes functions, and host-pathogen relationships with special emphasis on protozoan activity and the infection outcome. This review will also address how this chemical dialog can be explored to identify new therapeutic interventions against microbial infections and parasitic diseases.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Yan C, Li X, Zhang G, et al (2026)

The Regulatory Role of Quorum Sensing-Mediated Amino Acid Metabolism in Biofilm Formation and Motility of Hafnia alvei H4.

Foods (Basel, Switzerland), 15(2): pii:foods15020281.

The spoilage phenotype of microorganisms is a key mechanism leading to food spoilage, but how their metabolic environment affects the spoilage phenotype remains unclear. This study utilized metabolomics and spoilage phenotype analysis to reveal metabolic differences between different quorum sensing (QS) genotypes of Hafnia. alvei H4 and their impact on spoilage phenotypes. Ultra-high performance liquid chromatography-fluorescence detection revealed that the QS system participated in the differential metabolic regulation of eight amino acids, with serine exerting the most significant influence on the spoilage phenotype. Subsequent studies demonstrated that QS-promoted serine inhibited bacterial motility by affecting the biosynthesis of rhamnolipid (rather than c-di-GMP) and inhibiting flagellar/chemotactic genes expression. Moreover, QS-promoted serine induced the difference of bacterial inner membrane, further inhibiting bacterial motility. These findings provided fundamental information for the control of biofilms conformation within complex food nutritional background.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Elbehiry A, AI Alajaji (2026)

Next-Generation Strategies for Controlling Foodborne Pathogens: Precision Antimicrobials, Biofilm Disruption, and Emerging Molecular Interventions.

Foods (Basel, Switzerland), 15(2): pii:foods15020194.

Foodborne diseases remain a major global challenge because pathogenic microorganisms persist in food systems, often protected by biofilms and increasing resistance to conventional chemical preservatives and sanitizers. Control strategies that were effective in the past are becoming less reliable in complex processing environments, creating a need for more precise and adaptable food-safety approaches. This review examines emerging technologies that shift food safety from broad, reactive control toward targeted, data-driven intervention. Biological tools, including bacteriophages, phage-derived enzymes, bacteriocins, quorum-sensing inhibitors, and gene-guided antimicrobial systems, are discussed for their capacity to selectively control specific pathogens while limiting unintended effects on beneficial microbiota. The review also addresses nano-enabled strategies that improve antimicrobial stability, delivery, and performance, along with plant-derived and microbial bioactive compounds that support clean-label and sustainable preservation. In parallel, advances in anti-biofilm surface engineering, such as nano-textured, contact-active, and responsive materials, are examined as preventive measures to reduce microbial attachment and persistence on food-contact surfaces. Beyond individual interventions, this review emphasizes integration within coordinated multi-hurdle systems supported by real-time monitoring and predictive analytics. Emerging digital frameworks, including digital twins of food-processing lines, are highlighted as tools to link detection, risk prediction, and targeted control. Finally, remaining knowledge gaps, regulatory challenges, and research priorities are identified, highlighting the need for realistic testing, long-term safety evaluation, standardized validation, and collaborative efforts to translate precision food-safety technologies into dependable real-world applications.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Ilieva L, Baev V, Marhova M, et al (2026)

Potential of Fermented Food-Derived Lactiplantibacillus Cell-Free Supernatants to Control Staphylococcus aureus Growth and Biofilm Development.

International journal of molecular sciences, 27(2): pii:ijms27020760.

Staphylococcus aureus biofilms represent a critical healthcare challenge, driving chronic infections and antimicrobial resistance. This study investigates the anti-staphylococcal efficacy of two Lactiplantibacillus strains isolated from traditional Bulgarian pickled vegetables (turshiya): L. plantarum IZITR_24 and L. paraplantarum IZITR_13. Combining whole genome sequencing (WGS) with functional assays, we established a robust genotype-to-phenotype framework to characterize their antimicrobial arsenal. Based on WGS, we identified conserved plantaricin (plnJK, plnEF) clusters in both isolates, with IZITR_13 additionally carrying genes for pediocin and enterolysin A-alongside the confirmed absence of virulence factors. Reconstituted lyophilized cell-free supernatants (LCFSs) were evaluated in dose-response microtiter assays to determine the minimum biofilm inhibitory concentration (MBIC) and minimum inhibitory concentration (MIC). Both strains demonstrated clear, dose-dependent inhibitory activity against the S. aureus growth and biofilm formation. Microscopy (SEM/CLSM) confirmed significant biofilm disruption and cell membrane permeabilization. The observed consistency between genome-inferred capacity and phenotypes highlights the strong predictive value of a genome-first screening approach for selecting bacteriocin-producing lactic acid bacteria (LAB). These findings position IZITR_24 and IZITR_13 as promising postbiotic producers with potent antibiofilm activity against S. aureus. By utilizing their stable postbiotic products rather than relying on live colonization, this study proposes a targeted, antibiotic-sparing strategy to combat persistent staphylococcal biofilms.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Pompilio A, G Di Bonaventura (2026)

An Unexpected Inverse Relationship Between Biofilm Formation and Antibiotic Resistance in Stenotrophomonas maltophilia.

Antibiotics (Basel, Switzerland), 15(1): pii:antibiotics15010085.

Background/Objectives: Stenotrophomonas maltophilia is an opportunistic pathogen causing severe infections, particularly in patients with cystic fibrosis (CF). Its intrinsic multidrug resistance and biofilm-forming capacity complicate treatment. Although biofilms are generally associated with antimicrobial tolerance, the relationship between biofilm formation and planktonic antibiotic resistance in S. maltophilia remains poorly understood. This study investigated the association between antibiotic resistance profiles and biofilm production in clinical isolates from CF and non-CF patients. Methods: A total of 86 clinical isolates (40 from CF airways and 46 from non-CF patients) were analyzed. Susceptibility to seven antibiotics was assessed by disk diffusion, and multidrug resistance profiles were defined using standard criteria. Biofilm formation was quantified after 24 h using a crystal violet microtiter plate assay and categorized by using a semiquantitative scale. Results: High resistance rates were observed, particularly to meropenem (87.2%), ciprofloxacin (80.2%), and rifampicin (72.1%). CF isolates exhibited significantly higher resistance to piperacillin/tazobactam and a greater prevalence of multidrug resistance. Biofilm formation was detected in 94.2% of isolates, with strong or powerful producers predominating. However, CF isolates formed significantly less biofilm than non-CF isolates. Notably, resistance to piperacillin/tazobactam and meropenem was associated with reduced biofilm biomass and a lower proportion of high biofilm producers. Across all isolates, an inverse correlation was observed between the number of antibiotic resistances and biofilm biomass. These trends persisted after stratification by clinical origin, although some comparisons did not reach statistical significance. Conclusions: This study reveals an unexpected inverse relationship between planktonic antibiotic resistance and biofilm-forming capacity in S. maltophilia. Enhanced biofilm production may represent an alternative persistence strategy in more antibiotic-susceptible strains, with important implications for infection management and therapeutic failure.

RevDate: 2026-01-28
CmpDate: 2026-01-28

Teskey SJL, Khoma L, Lorbes M, et al (2026)

Nitric Oxide-Releasing Gels in the Context of Antimicrobial Stewardship, Biofilm Management, and Wound-Repair Biology.

Antibiotics (Basel, Switzerland), 15(1): pii:antibiotics15010054.

Topical antibiotics have long been used for the prevention and treatment of superficial skin and soft tissue infections; however, increasing evidence indicates that their clinical value is undermined by rising antimicrobial resistance, high rates of allergic sensitization, inadequate activity against biofilms, and a lack of wound-healing properties. Agents such as bacitracin, neomycin, polymyxin B, mupirocin, and fusidic acid act through narrow, target-specific mechanisms that facilitate resistance selection and provide limited benefit in chronic or polymicrobial wound environments. Contemporary antimicrobial stewardship frameworks therefore discourage routine use of topical antibiotics and increasingly favor non-antibiotic antiseptics with broad-spectrum activity and low resistance risk, including silver, iodine, polyhexamethylene biguanide, octenidine, and medical-grade honey. These modalities, however, primarily serve to reduce microbial burden and do not directly address the underlying biological impairments that prevent healing. Nitric oxide-releasing gels (NORGs) represent a novel class of topical antimicrobials that combine multi-target bactericidal activity with physiologic pro-healing effects. Nitric oxide exerts potent antimicrobial and antibiofilm effects via oxidative and nitrosative stress, disruption of metabolic pathways, inhibition of DNA replication, and interference with quorum sensing. Simultaneously, nitric oxide enhances angiogenesis, modulates inflammation, improves microvascular perfusion, and promotes fibroblast and keratinocyte function. Preclinical models and early-phase clinical studies demonstrate broad-spectrum efficacy-including activity against multidrug-resistant organisms-with favorable tolerability and minimal risk of resistance development. Although the current evidence base remains preliminary, NORGs offer a promising antimicrobial platform with the potential to reduce reliance on topical antibiotics while simultaneously addressing key barriers to wound healing. Larger randomized controlled trials, direct comparisons with established advanced dressings, and robust pharmacoeconomic evaluations are needed to define their optimal role within stewardship-aligned wound-care practice.

RevDate: 2026-01-28
CmpDate: 2026-01-27

Kotay SM, Parikh HI, Gweon HS, et al (2026)

Biofilm removal in hospital sink drains drives unintended surges in antibiotic resistance.

npj antimicrobials and resistance, 4(1):5.

The prevalence and proliferation of antimicrobial-resistant bacteria is considered one of the critical issues of our time. Wastewater is a habitat for complex microbial communities where bacteria share antimicrobial-resistance genes through horizontal gene transfer. Hospital wastewater plumbing systems are an ideal reservoir for environmental and pathogenic bacteria to interface and exchange antimicrobial-resistance genes. Replacement of contaminated plumbing may be the most intuitive and widely deployed response to the detection and colonization of highly-resistant potentially pathogenic bacteria in hospital sink drains. In this study, we analyzed sink-drain biofilms from six intensive-care patient rooms using shotgun metagenomic sequencing and microbial culture. We show an evident shift in biofilm community structure toward increased abundance of Enterobacteriaceae following plumbing replacement. Higher resistome load and abundance of clinically relevant resistance and typically encountered mobile genes in the newly replaced plumbing was also observed. Taken together, these finding suggest that exchanging contaminated plumbing for new plumbing may actually have the unexpected consequence of increased abundance of Enterobacterales and antimicrobial-resistance genes in the sink drains. Disruption of preexisting complex environmental biofilms may result in an unintended microbial population shifts and a potential subsequent increase in the amount of antimicrobial-resistant Enterobacterales which are targeted for elimination.

RevDate: 2026-01-27

Yang W, Wang X, Liu S, et al (2026)

Dual-species biofilm formation of Pseudomonas fluorescens and Hafnia alvei and their susceptibility to penicillin V acylase from Lactiplantibacillus plantarum YP4-1-2.

International journal of food microbiology, 450:111657 pii:S0168-1605(26)00037-1 [Epub ahead of print].

Food spoilage typically arises from bacterial consortia rather than individual species. Pseudomonas fluorescens and Hafnia alvei employ quorum sensing (QS)-mediated biofilm formation to accelerate spoilage in salmon. This study constructed a dual-species biofilm model of P. fluorescens and H. alvei to simulate the actual spoilage environment in salmon, and investigated the anti-biofilm potential of penicillin V acylase (LpPVA) from Lactiplantibacillus plantarum YP4-1-2 against mono- and dual-species systems. The results showed that a more compact dual-species biofilm with elevated levels of AHLs, higher metabolic activity, and greater extracellular polymeric substances (EPS) was observed when P. fluorescens and H. alvei were co-cultured at a ratio of 1:1. In salmon juice, the inhibitory effect of LpPVA against P. fluorescens, H. alvei, and dual-species biofilm were significantly higher than that in the LB medium, reaching 66.93%, 70.71%, and 63.66% respectively. LpPVA also significantly reduced AHL levels and suppressed both metabolic activity and EPS production in P. fluorescens, H. alvei, and dual-species biofilms, with inhibitory rates on AHLs of 97.23%, 95.18% and 98.30%, respectively; on metabolic activity of 50.16%, 47.08% and 51.16%, respectively; and on extracellular polysaccharides and proteins of 75.78% and 40.10%, 78.63% and 46.01%, 67.42% and 50.68%, respectively. Additionally, LpPVA down-regulated QS-related genes and biofilm-related genes to inhibit biofilm formation. The study demonstrates that the interactions between P. fluorescens and H. alvei in a dual-species promoted the formation of complex biofilm structures by increasing AHLs, and their sensitivity to LpPVA provides a novel strategy for controlling multi-species contamination in aquatic products.

RevDate: 2026-01-27
CmpDate: 2026-01-27

Schöpf C, Geschwindt A, Knapp M, et al (2025)

Amphibian-Derived Peptide Analog TB_KKG6K: A Powerful Drug Candidate Against Candida albicans with Anti-Biofilm Efficacy.

Journal of fungi (Basel, Switzerland), 12(1): pii:jof12010011.

Candida albicans, a commensal and opportunistic fungal pathogen, is a major clinical concern due to its ability to cause infections ranging from mild mucosal conditions to life-threatening systemic diseases, particularly in immunocompromised patients. Its capacity to form biofilms on medical devices further complicates treatment by enhancing antifungal resistance and immune evasion. In the search for novel therapeutic strategies, the lysine-enriched amphibian-derived temporin B analog, TB_KKG6K, has emerged as a promising antifungal agent. This study demonstrates that TB_KKG6K exhibits potent fungicidal activity against planktonic C. albicans cells, with a low potential to induce adaptation or resistance. TB_KKG6K has no adverse impact on the anti-Candida efficacy of standard antifungal drugs when applied in combination, interacting additively with amphotericin B and caspofungin in a fungicidal mode of action. Additionally, TB_KKG6K effectively reduces biofilm maturation on silicone elastomers, a material commonly used in medical devices, further highlighting its therapeutic potential. These data together with our previous documentation of minimal cytotoxicity and irritation potential in human cells makes TB_KKG6K a strong candidate for combating both planktonic and biofilm-associated C. albicans infections. These findings underscore the dual efficacy of TB_KKG6K and its potential to address the challenges posed by C. albicans in clinical settings.

RevDate: 2026-01-27
CmpDate: 2026-01-27

Sato Y, Watanabe Y, Ayabe T, et al (2026)

Inhibition of Streptococcus Biofilm Formation by 6'-Sialyllactose and N-Acetylneuraminic Acid.

Dentistry journal, 14(1): pii:dj14010041.

Background/Objectives: Oral hygiene is crucial for maintaining overall health, as poor oral care can lead to various systemic diseases. Although xylitol is widely used to inhibit plaque formation, more effective agents are needed to control oral biofilms. Herein, we evaluated the inhibitory effects of sialyllactose (SL), a type of human milk oligosaccharide (HMO), and its partial structure N-acetylneuraminic acid (Neu5Ac) against Streptococcus biofilm. Methods: Under a CO2 atmosphere, Streptococcus mutans and mixed Streptococcus species were each cultivated in vitro, and the inhibitory effects of HMOs [2'-fucosyllactose, 3'-sialyllactose (3'-SL) and 6'-sialyllactose (6'-SL)] and Neu5Ac on biofilm formation were evaluated. Bacterial biofilm formation was quantified using the crystal violet assay. Biofilm architecture and viability were visualized using confocal laser-scanning microscopy (CLSM) with SYTO9/propidium iodide staining. Transcriptomic responses of S. mutans biofilms to the test compounds were analyzed by RNA-Seq. Statistical analysis was performed using one-way analysis of variance followed by Tukey's test. Results: SLs and Neu5Ac at 100 mM significantly inhibited S. mutans biofilm formation, with stronger effects than those of xylitol. The inhibitory effects varied among HMOs, with 6'-SL being more effective than 3'-SL and Neu5Ac being most effective. These effects were consistent in assays targeting biofilms formed by other S. mutans strains and in a mixed biofilm comprising Streptococcus species. Gene expression analysis suggested that the inhibitory mechanism involves the physical inhibition of surface adhesion and stress-induced regulation of gene expression. Conclusions: This study provides insights into the physiological significance of HMOs in the oral cavities of humans. HMOs exhibited potential as functional foods to control oral biofilm formation and reduce the risk of oral and systemic diseases.

RevDate: 2026-01-27

Hosseinali Z, Jeddi F, Niapour A, et al (2026)

Inhibition of Biofilm Formation and Gene Expression by Silicon Dioxide Nanoparticles and Zinc Oxide/Zeolite Nanocomposites on Streptococcus mutans.

Recent advances in anti-infective drug discovery pii:RAAIDD-EPUB-152819 [Epub ahead of print].

BACKGROUND: Streptococcus mutans (S. mutans) is recognized as the primary oral pathogen responsible for dental caries. The formation of biofilms on tooth surfaces is a crucial virulence factor for S. mutans. This study aimed to investigate the antimicrobial and anti-biofilm effects of silicon dioxide nanoparticles (SiO2 NPs) and zinc oxide/zeolite nanocomposites (ZnO/Zeolite NCs) on S. mutans gene expression and biofilm formation.

METHODS: Minimum inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), sub-MIC, safranin staining, growth curve analysis, and MTT assays were performed to evaluate the anti-biofilm properties of the nanoparticles. The expression levels of the ftf, gtfB, vicR, and gbpB genes were evaluated by real-time PCR. Cytotoxic effects of the nanoparticles were measured by the MTT assay with human gingival fibroblast (HGF2PI2) cells.

RESULTS: Both SiO2 NPs and ZnO/Zeolite NCs effectively inhibited S. mutans biofilm formation, with MTT assay results showing a 79% inhibition by SiO2 NPs and 95% by ZnO/Zeolite NCs. Additionally, both nanoparticles reduced the transcription levels of the ftf, gtfB, vicR, and gbpB genes, with no toxic effects observed on HGF2PI2 cells at a concentration of 32 mg/ml.

DISCUSSION: These findings suggest that SiO2 NPs and ZnO/Zeolite NCs are promising agents against S. mutans biofilms, with potential applications in oral care products.

CONCLUSION: SiO2 NPs and ZnO/Zeolite NCs show significant potential for preventing biofilm formation by S. mutans, representing effective and cost-efficient antibacterial options for oral health.

RevDate: 2026-01-27
CmpDate: 2026-01-27

Jasim HF, Majeed NS, Salam AA, et al (2026)

Antibiotic Resistance, Biofilm Genes, and smeDEF Efflux Pump in Clinical Stenotrophomonas maltophilia Isolates From Iran.

MicrobiologyOpen, 15(1):e70222.

Stenotrophomonas maltophilia is a nosocomial and opportunistic microorganism with increasing antibiotic resistance rates. This study aimed to assess its biofilm production capacity, antibiotic resistance distribution, and the prevalence of biofilm- and resistance-related genes in clinical isolates. In this multiinstitutional study, 230 isolates were collected from hospitals across Iran between 2022 and 2024. Resistance trends were evaluated using disc diffusion and minimal inhibitory concentration E test methods, per Clinical and Laboratory Standards Institute guidelines. Crystal violet staining assessed biofilm production, while polymerase chain reaction (PCR) sequencing identified biofilm- and resistance-related genes. Real-time PCR was used to evaluate the relative expression of the smeD, smeE, and smeT genes, calibrated against TMP/SMX-sensitive control strains. Susceptibility rates to trimethoprim/sulfamethoxazole (TMP/SMX), levofloxacin, and minocycline were 97.39%, 93.47%, and 93.04%, respectively. TMP/SMX-resistant strains showed 19.8- and 16-fold higher expression of smeD and smeE, compared with sensitive isolates. The spgM gene was detected in all isolates, and 93.04% (n = 214) were biofilm producers, with most showing moderate-biofilm formation (n = 89, 38.70%). Additionally, the rpfF gene was closely associated with strong-biofilm formation (p ≤ 0.05). The L2, L1, smqnr, sul2, and sul1 resistance genes were identified in 214 (93.04%), 181 (78.69%), 135 (58.7%), 136 (59.1%), and 127 (55.2%) isolates, respectively. Our findings demonstrate that most isolates remain sensitive to TMP/SMX, while resistance to alternative antibiotics is rising. Moreover, biofilm production appears significantly associated with the rpfF gene.

RevDate: 2026-01-26

Shi L, Xu M, Tang S, et al (2026)

Study on drug resistance, biofilm formation, phylogenetic and virulence gene analysis of Escherichia coli from diarrheic lambs.

BMC veterinary research pii:10.1186/s12917-026-05296-z [Epub ahead of print].

RevDate: 2026-01-26

Ayenero ME, Kumar R, Wang HC, et al (2026)

The transcriptional regulator AphB[vp] is involved in virulence gene expression and biofilm formation in Vibrio parahaemolyticus.

International journal of biological macromolecules pii:S0141-8130(26)00430-7 [Epub ahead of print].

Acute hepatopancreatic necrosis disease (AHPND) is a serious bacterial disease impacting shrimp farming worldwide. The disease was originally found to be caused by a specific strain of Vibrio parahaemolyticus harboring a unique ~70-kbp plasmid encoding the binary PirA[vp] and PirB[vp] toxins. We have previously shown that AphB[vp] regulates the expression of these toxins. In this study, we investigated the role of AphB[vp] in regulating key genes associated with V. parahaemolyticus virulence and survival by using next-generation sequencing (NGS) of wild-type (3HP) and aphB[vp]-deleted mutant (ΔaphB[vp]) strains. Our RT-qPCR validation of NGS data showed that 6 genes, hns[vp], dgc[vp], t6ss[vp], tssB[vp], ifp[vp] and DNA mtase[vp] were significantly downregulated in the ΔaphB[vp] compared to the 3HP, while vcrH[vp] was upregulated. Electrophoretic mobility shift assays (EMSA) confirmed that AphB[vp] directly binds to the promoter regions of hns[vp], dgc[vp] and t6ss[vp]. Notably, AlphaFold structural prediction indicates that DGC[vp] is a diguanylate cyclase involved in producing cyclic-di-GMP (c-di-GMP), a key second messenger for bacterial biofilm formation and persistence. An intracellular c-di-GMP assay further showed that the concentration of c-di-GMP in the ΔaphB[vp] was significantly lower than in the 3HP, while crystal violet staining and scanning electron microscopy revealed significant changes in both the biomass and structure of the biofilm formed by the ΔaphB[vp]. Collectively, our findings suggest that AphB[vp] could be a key regulator for V. parahaemolyticus virulence and biofilm formation. This study of the integrated AphB[vp] regulatory network deepens our understanding of the pathogenesis of AHPND and offers potential targets for disease control strategies.

RevDate: 2026-01-28
CmpDate: 2026-01-26

Luu CH, Moonshi SS, Nepal A, et al (2026)

Antithrombotic and antibacterial surface coating based on spiky silver nanoparticles: A counterattack against clotting and biofilm.

Materials today. Bio, 37:102762.

Blood-contacting medical devices such as vascular grafts, stents, and catheters are indispensable in life-saving interventions but remain prone to thrombosis and bacterial infection. These complications are often synergistic, with clot formation facilitating bacterial colonisation and biofilm growth, yet most surface coatings lack active countermeasures once thrombi or biofilms have developed. In this study, we hypothesised that integrating spiky silver-coated iron oxide nanoparticles (AgIONPs) with poly(ethylene glycol) (PEG) into a surface coating could provide both passive and active protection. AgIONPs offer strong photothermal properties under 808 nm laser irradiation for on-demand thrombolysis and biofilm disruption, while PEG contributes antifouling, anticoagulant, and biocompatible characteristics. The optimised AgIONPs-PEG coating exhibited safe photothermal heating (<45 °C), effectively lysed thrombi in static and dynamic models, and disrupted most biofilm biomass after a single irradiation cycle. Antithrombogenicity assays confirmed PEG's ability to reduce biofouling and improve haemocompatibility. Biocompatibility was further validated through in vitro, in ovo, and in vivo assays, with reduced immune-mediated inflammation. These findings highlight a multifunctional, responsive coating that could extend the lifespan and reliability of blood-contacting devices, offering a promising platform for next-generation photothermal materials in biomedical applications.

RevDate: 2026-01-28
CmpDate: 2026-01-26

Dee Manuel MP, Shih YH, Hsia SM, et al (2026)

Evaluating thymol vapor for biofilm removal and biocompatibility in curved root canal models in vitro.

Journal of dental sciences, 21(1):323-332.

BACKGROUND/PURPOSE: Conventional irrigants such as chlorhexidine and sodium hypochlorite have strong antimicrobial properties but high cytotoxicity, limiting their use in regenerative endodontics. We hypothesized that thymol vapor could provide effective antibacterial activity with lower cytotoxicity.

MATERIALS AND METHODS: The antimicrobial activity of thymol in both liquid and vapor phases was tested against Enterococcus faecalis, Streptococcus mutans, and Aggregatibacter actinomycetemcomitans using a resin block model simulating curved root canals. The effect of thymol vapor, alone or with mechanical instrumentation, was tested on early-stage biofilms removal. Cytotoxicity was assessed using MTT assays in L-929 fibroblasts and MG-63 osteoblast-like cells, and pro-inflammatory cytokine gene expression (IL-1β, TNF-α, IL-6) was measured via qRT-PCR.

RESULTS: Thymol exhibited minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) values of 0.8-1.0 mg/mL in planktonic cultures. In early-stage biofilms models, 10-100 mg/mL liquid thymol and 5.0 mg/mL thymol vapor significantly reduced bacterial viability. Combining 1.0 mg/mL thymol vapor with mechanical instrumentation enhanced early-stage biofilms removal, particularly against E. faecalis. Direct exposure to thymol and chlorhexidine caused significant cytotoxicity, while 1.0 mg/mL vapor showed lower cytotoxic and did not significantly induce pro-inflammatory cytokine genes in L-929 cells. At higher concentrations, MG-63 cells exhibited increased cytokine expression.

CONCLUSION: This study is the first to propose thymol vapor for biofilm removal in curved root canal models and to demonstrate its antibacterial activity with lower cytotoxicity than conventional irrigants. Its potential as an adjunct in regenerative endodontics merits further investigation, particularly in relation to immunomodulatory effects.

RevDate: 2026-01-28
CmpDate: 2026-01-26

Enggardipta RA, Akizuki M, Bando M, et al (2026)

Trimethyl chitosan: Antibacterial activity on Enterococcus faecalis biofilm and cytocompatibility on human periodontal ligament fibroblasts cells.

Journal of dental sciences, 21(1):150-158.

BACKGROUND/PURPOSE: Effective disinfection of the root canal system remains a major challenge due to complex anatomy and the persistence of biofilm-forming bacteria such as Enterococcus faecalis. Trimethyl chitosan (TMC), a quaternized chitosan derivative, has shown promising antimicrobial properties but has not been extensively studied for endodontic use. This study aimed to evaluate the antibacterial and antibiofilm efficacy of TMC against E. faecalis and assess its cytocompatibility with human periodontal ligament fibroblasts (HPdLFs).

MATERIALS AND METHODS: The E. faecalis biofilm formation in the presence of TMC and antibacterial activity of TMC against mature E. faecalis biofilms were evaluated using crystal violet staining, adenosine triphosphate assays, colony forming unit counting, scanning electron microscopy, and fluorescence microscopy. The expression of genes associated with E. faecalis biofilm formation, such as ace, esp, and gelE, was determined. Moreover, cytocompatibility of TMC with HPdLFs was assessed using a cell counting kit-8 assay.

RESULTS: TMC significantly inhibited biofilm formation by E. faecalis and in the mature E. faecalis biofilm, TMC interfered with the total biofilm biomass, reduced bacterial numbers, weakened the biofilm structure, and upregulated ace, esp, and gelE expression. Furthermore, a lower concentration of TMC maintained HPdLFs viability.

CONCLUSION: This study highlights the potential of TMC as a novel irrigating material owing to its antibacterial and antibiofilm activities against E. faecalis and its cytocompatibility with HPdLFs.

RevDate: 2026-01-25

Marzullo P, Presentato A, Campisciano V, et al (2026)

Surficial N[+] Charge Density as Key Factor for Inhibition of Pseudomonas Biofilm Formation in Non-Leaching Quaternary Ammonium-Modified Polydimethylsiloxane Coatings.

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

Marine biofouling represents significant environmental and economic concerns, highlighting the need for sustainable and non-leaching antifouling materials. In this work, we developed cross-linked polydimethylsiloxane (PDMS) coatings functionalized with methyldimethoxysilanes bearing quaternary ammonium groups and alkyl side chains of two different lengths (C8 and C12). [29]Si and [13]C solid-state nuclear magnetic resonance (CP-MAS NMR) and Fourier-transform infrared spectroscopy (FTIR) confirmed the successful incorporation of silanes into the polymer matrix. Surface analysis was carried out by fluorescein assay, surface roughness, and contact angle measurements. Antifouling assays against Pseudomonas delhiensis PS27, a robust Gram-negative strain exhibiting strong resilience to environmental stresses, demonstrated notable biofilm inhibition in coatings with higher charge surface density without affecting the physiological fitness of planktonic cells. An observed minimum effective value of surface charge density (6.23 ± 0.76)·10[16] N[+]/cm[2] for biofilm inhibition was observed. These findings suggest a link between surficial N[+] charge density and antifouling efficacy. The developed coatings represent a promising and durable strategy for environmentally friendly fouling prevention in marine and aquatic environments.

RevDate: 2026-01-24

Zhang X, Quan M, Zong Z, et al (2026)

Ursodeoxycholic acid inhibits biofilm formation and bacterial adhesion of Clostridioides difficile.

Anaerobe pii:S1075-9964(26)00003-X [Epub ahead of print].

UDCA exhibits limited direct bacteriostatic activity against Clostridioides difficile with a high MIC90 of >128 μg/mL against 121 clinical strains. However, compared with vancomycin, UDCA significantly impedes biofilm formation and bacterial adherence at subinhibitory concentrations, which may be the therapeutic advantages of UDCA and support this old drug to be further developed for CDI prevention.

RevDate: 2026-01-25

Zhang K, Gao J, Guo Y, et al (2026)

Distinct influence of preservatives on microbial community and resistance gene in bio-carriers biofilm and microplastics biofilm as revealed in sulfur autotrophic denitrification coupled with anammox system.

Environmental research, 294:123831 pii:S0013-9351(26)00159-3 [Epub ahead of print].

Microplastics (MPs) can act as a carrier of microorganisms and form a distinct ecological niche. Methylparaben (MeP) and benzethonium chloride (BZC) are commonly used as preservatives in daily life and co-exist with MPs in wastewater environment. This study comprehensively examined the diverse characteristics of resistance genes (RGs) and the microbial communities in both bio-carriers biofilm and MPs biofilm, along with the performance variations in sulfur autotrophic denitrification coupled with anammox (SAD/A) under co-exposure to MeP (0.5 mg/L) and BZC (0.5-2 mg/L). Results showed that co-exposure to 0.5 mg/L MeP and 2 mg/L BZC decreased the total nitrogen removal efficiency of SAD/A (from 95.16% to 75.36%). Preservatives exhibited the enhanced effect on the prevalence of intracellular RGs and extracellular RGs, which was stronger in MPs biofilm (1.33 × 10[5]-1.53 × 10[6] copies/ng DNA) than in bio-carriers biofilm (3.58 × 10[5]-9.08 × 10[6] copies/ng DNA). Stappia, Microbacterium and Acidovorax identified as pathogenic bacteria, exhibited higher abundance in MPs biofilm (0.46%-2.11%) than in bio-carriers biofilm (0.24%-1.71%). In both bio-carriers biofilm and MPs biofilm, the microbial community assembly was predominantly driven by stochastic processes, with preservatives inducing enrichment of potential RGs hosts. These findings provided important insights into different ecological characteristics of MPs and bio-carriers in SAD/A system under preservatives exposure, which offers references for the management and risk assessment of preservatives and MPs.

RevDate: 2026-01-23
CmpDate: 2026-01-23

Sakai R, Zhao Y, M Robert (2026)

LOTUS: A low-cost time-lapse automated imaging system for spatio-temporal analysis of microbial colony or biofilm development.

PloS one, 21(1):e0339652.

The proliferation of low-cost single-board computers and 3D printers has considerably accelerated open science. In the life sciences, for both research and educational purposes, there is a growing trend to develop affordable imaging systems rather than purchasing specialized commercial instruments. However, existing solutions often lack diversity of imaging modes or adequate throughput. To fill this gap, we developed LOTUS, a low-cost (~$550 USD) automated imaging system built from 3-D printed components that integrates motorized sample positioning with interchangeable light-emitting diodes (LED) sources and optical filters for spatio-temporal analysis of microbial colony or biofilm development. LOTUS images up to nine samples at fixed time intervals (e.g., 20 min) in four modes: bright-field transillumination (biomass), bright-field epi-illumination (morphology), and dual-color epi-fluorescence (gene expression or other types of reporter analysis). Validation experiments demonstrated stable and reproducible timing and positioning accuracy over 3 days and homogeneity of LED illumination and captured images enabling semi-quantitative analysis. We demonstrated LOTUS capabilities by imaging E. coli biofilms expressing fluorescent reporter proteins (GFPmut2 and mCherry) over 5 days and tracking fluorescence intensity dynamics following sub-MIC ampicillin treatment. LOTUS represents a versatile and cost-effective semi-quantitative platform for parallel monitoring of colony or biofilm development and fluorescent reporter expression pattern. This open-source system makes automated time-lapse live imaging accessible for research and educational applications.

RevDate: 2026-01-23

Zhou Q-Q, Y Wan (2026)

Mechanisms of microbial colonization in biofilm-associated infections of hemodialysis catheters and advances in surface modification technologies.

Clinical microbiology reviews [Epub ahead of print].

SUMMARYHemodialysis catheter-related bloodstream infections (CRBSIs), primarily driven by microbial colonization and biofilm formation, represent a major cause of morbidity and mortality in patients with end-stage renal disease. Key pathogens such as Staphylococcus aureus and Pseudomonas aeruginosa employ sophisticated virulence mechanisms, including microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) and quorum-sensing (QS) systems, to establish resilient biofilms. Surface modification technologies-encompassing antibacterial coatings, antithrombotic modifications, antibiofilm technologies, surface topological optimization, and tip design innovations-offer promising "anti-colonization" strategies to prevent infections. Notably, while tunneled and non-tunneled catheters exhibit distinct biofilm dynamics and clinical risk profiles, emerging multifunctional coatings demonstrate the potential for enhancing long-term catheter safety and performance. However, the clinical translation of these innovations requires overcoming challenges related to biocompatibility, long-term durability, and scalable manufacturing, necessitating interdisciplinary collaboration.

RevDate: 2026-01-23
CmpDate: 2026-01-23

Adkins PE, Yarawsky AE, AB Herr (2026)

The secreted staphylococcal biofilm protein Sbp forms biomolecular condensates in the presence of DNA.

Protein science : a publication of the Protein Society, 35(2):e70485.

Staphylococcus epidermidis is the leading cause of device-related infections, primarily due to its ability to form biofilms, surface-adherent bacterial communities that confer remarkable resistance to antibiotics and host defenses. Small basic protein, Sbp, is a 16-kDa protein expressed by S. epidermidis that has been shown to be crucial for biofilm formation, but little is known about its function. Sbp features a high proportion of basic residues as well as several predicted regions of intrinsic disorder. Consistent with its high positive charge density, Sbp is shown here to interact with double-stranded DNA, a ubiquitous component of the biofilm matrix, forming soluble complexes or large aggregates with short or longer DNA oligonucleotides, respectively. The observed multivalent interaction of Sbp with DNA along with its predicted disorder suggested that it might form biomolecular condensates with DNA. Confocal and differential interference contrast microscopy revealed that Sbp and dsDNA form phase-separated droplets and/or solid aggregates, depending on the concentration and stoichiometry of Sbp and DNA as well as the DNA oligonucleotide length. Fluorescence recovery after photobleaching experiments demonstrated that Sbp-DNA condensate droplets initially exhibit liquid-like behavior but gradually transition to a gel-like state. This work provides the first evidence that Sbp binds DNA and undergoes biomolecular condensation, revealing a previously unrecognized mechanism that may contribute to biofilm matrix organization in S. epidermidis.

RevDate: 2026-01-22

Einarsson GG, Das S, Silversides JA, et al (2026)

Biofilm communities above and below the cuff of endotracheal tubes are spatially homogenous.

Respiratory research pii:10.1186/s12931-025-03485-2 [Epub ahead of print].

RevDate: 2026-01-22

Pathoor NN, Ganesh PS, Gopal RK, et al (2026)

Attenuation of biofilm-encoding genes and virulence attributes in clinical isolates of Acinetobacter baumannii by essential oil derived from Myroxylon balsamum.

Scientific reports, 16(1):2861.

RevDate: 2026-01-22

Yang Y, Huang Y, Wang Z, et al (2026)

Microbial insights into simultaneous linear alkylbenzene sulfonate and nitrogen removal from greywater in a biofilm reactor under varying treatment loadings.

Environmental research pii:S0013-9351(26)00122-2 [Epub ahead of print].

The unpredictable treatment loadings of greywater present a challenge for decentralized greywater treatment. This study developed a gravity-flow self-oxygenating granular activated carbon-based multifunctional dynamic biofilm reactor (GAC-MDBfR) for the efficient and low-energy removal of linear alkylbenzene sulfonates (LAS) and nitrogen from source-diverted greywater under varying hydraulic loadings (0.58-2.00 m[3]/(m[2]·d)). The results showed that the GAC-MDBfR exhibited efficient and simultaneous removal of organics and nitrogen over a hydraulic loading (HL) range of 0.58-1.00 m[3]/(m[2]·d). Optimal greywater purification occurred at an HL of 1.00 m[3]/(m[2]·d), achieving removal ratios of chemical oxygen demand, NH4[+]-N, total nitrogen, and LAS of 95.6%, 99.1%, 82.5% and 97.0%, respectively. Higher HLs and fluctuating pollutant loadings resulted in compromised biofilm stability, along with high LAS biotoxicity and insufficient contact between pollutants and biofilm microbes, leading to reduced pollutant removal efficiency. The underlying microbial mechanism behind the effect of HL on GAC-MDBfR performance was investigated. Higher HLs led to a decrease in microbial diversity and the relative abundance of functional microorganisms involved in nitrogen and LAS metabolism. Furthermore, trends in the abundance of enzymes associated with LAS and nitrogen metabolism under different HLs were examined. The relative abundances of NH4[+]-N and LAS metabolic enzymes were governed by both hydraulic and pollutant loadings, whereas the relative abundances of NO3[-]-N metabolic enzymes were unaffected by the HL. These findings contribute to the development of the GAC-MDBfR and provide valuable insights for the biofilm reactors in treating greywater of varying quality and quantity, ultimately contributing to efficient and low-energy greywater treatment.

RevDate: 2026-01-22

Magalhães AP, Jorge P, Neiva J, et al (2026)

Contribution of viable but non culturable cells and small colony variants in antibiotic insusceptibility and therapeutic failure against S. aureus and P. aeruginosa biofilm co-infections.

Microbial pathogenesis pii:S0882-4010(26)00038-0 [Epub ahead of print].

P: aeruginosa and S. aureus are often co-isolated from biofilm-associated infections, such as those afflicting cystic fibrosis (CF) patients. Biofilms, along with the interspecies interactions, play a significant role in fostering antibiotic insusceptibility, contributing to infection chronicity. Previously, we showed that S. aureus adopts a viable but non-culturable (VBNC) state in biofilms with P. aeruginosa. Here, we aimed to gain insight into the impact of VBNC and phenomena such as phenotypic switching on antimicrobial treatment and vice-versa. Single- and dual-species biofilms of two isolates from each species were characterised in terms of viability, culturability, clonal diversification, and pathogenic potential, upon treatment with ciprofloxacin and vancomycin. Data show that S. aureus became less susceptible to antibiotics in its VBNC state induced by P. aeruginosa and by the treatments. P. aeruginosa's susceptibility to ciprofloxacin diminished in dual-species biofilms, suggesting mutual benefits. Following treatment, S. aureus persisted as VBNC in the dual-species biofilm and its tolerance to ciprofloxacin endured after planktonic regrowth. P. aeruginosa triggered S. aureus's small colony variants (SCV), but P. aeruginosa's rugose SCV probably explains S. aureus's protection due to enhanced biofilm formation. This work sheds light on P. aeruginosa and S. aureus' co-increased tolerance to antibiotics, with cooperative interactions, phenotypic diversification, and VBNC underpinning this and the persistence of S. aureus within P. aeruginosa biofilms. This work is the first relating S. aureus's decreased susceptibility in dual-species biofilms to its VBNC state. Findings highlight the importance of microbial ecology, viability and colony morphotyping studies when designing treatments for multispecies infections.

RevDate: 2026-01-22

Sidikjan N, Li Y, Chen Y, et al (2026)

Multimedia profiling of metal resistance genes in the Yangtze Estuary: Biofilm dominance and community-driven regulatory pathways.

Ecotoxicology and environmental safety, 310:119769 pii:S0147-6513(26)00098-9 [Epub ahead of print].

Biofilms are critical microbial assemblages that function as sinks and potential reservoirs of metal resistance genes (MRGs) in contaminated aquatic systems. In this study, metagenomic sequencing and environmental profiling were employed to characterize MRGs distribution, heavy metal contamination, and microbial community structure across water, sediment, and biofilm samples in the Yangtze Estuary. Biofilms exhibited significantly higher concentrations of heavy metals and MRGs than other matrices, particularly for key genes such as corS (Cu-resistance), nrsS (Ni-resistance), and pbrA (Pb-resistance). Ecological risk assessment identified cadmium as the primary risk contributor, especially in biofilms. Partial redundancy analysis revealed that microbial community composition was the dominant factor shaping MRGs distribution, rather than metal concentrations alone. Network and canonical correspondence analyses further demonstrated strong co-occurrence patterns between MRGs and antibiotic resistance genes (ARGs), regulated by eutrophication (TN, Chl-a) and heavy metals (Pb, Cd, Cu). Notably, Pb-resistance genes in biofilm communities were significantly enriched and closely associated with Cyanobacteria and Proteobacteria, reflecting a multi-stage co-occurrence pattern potentially involving pbrT, pbrA, cadD, and czcD. These findings highlight the ecological significance of biofilms in MRGs enrichment, dissemination, and risk propagation in estuarine ecosystems under combined pollution stress.

RevDate: 2026-01-22
CmpDate: 2026-01-22

Htay TKK, Hathaway MR, J Daniel (2026)

Piperine inhibits biofilm formation and efflux activity and dysregulates lipid metabolism in Mycobacterium abscessus.

PloS one, 21(1):e0341420 pii:PONE-D-25-47157.

The nontuberculous Mycobacterium abscessus is a human pathogen that causes chronic lung infections and soft tissue infections. The bacterium forms biofilms and efflux pumps contribute to its tolerance of antibiotics. Efflux pumps also transport lipids and other molecules to the bacterial outer cell surface for biofilm formation. The effects of piperine, an alkaloid derived from black pepper, on biofilm formation, efflux activity and lipid biosynthesis in M. abscessus have not been reported. We report that, at sub-minimum inhibitory concentration levels, piperine inhibits biofilm formation in M. abscessus by more than 90%. We investigated lipid biosynthesis from exogenously supplied radiolabeled 14C-palmitic acid in M. abscessus during its log-phase growth and during biofilm formation and examined the effects of piperine. We report that piperine dysregulates the biosynthesis of major lipids in M. abscessus during biofilm formation. Piperine inhibited the biosynthesis of the neutral storage lipid triacylglycerol during biofilm formation by nearly 80% and the biosynthesis of the polar lipid trehalose monomycolate by 50%. In contrast, piperine stimulated the biosynthesis of the major polar lipid phosphatidylethanolamine during biofilm formation. Piperine inhibited efflux activity in M. abscessus by nearly 70%. Piperine enhanced the efficacies of four commonly used antibiotics used to treat M. abscessus infections. The minimum inhibitory concentration of clarithromycin was decreased by more than 16-fold by piperine and that of amikacin and cefoxitin by about 5-fold. The efficacy of ciprofloxacin was improved by more than 2-fold by piperine. This is the first report on the effects of piperine on lipid biosynthesis, efflux activity and biofilm formation in M. abscessus that highlights the potential importance of piperine as an adjunct therapy to treat nontuberculous mycobacterial infections.

RevDate: 2026-01-22

George SD, Amerson-Brown MH, Sousa LGV, et al (2026)

Spatial organization of Gardnerella species, Prevotella bivia, and Fannyhessea vaginae in the bacterial vaginosis biofilm.

Infection and immunity [Epub ahead of print].

Key bacterial vaginosis (BV)-associated bacteria implicated in biofilm formation include Gardnerella species, Prevotella bivia, and Fannyhessea vaginae. We investigated their spatial organization in the BV biofilm over time from longitudinal vaginal specimens obtained from women with incident BV (iBV) using peptide nucleic acid-fluorescence in situ hybridization (PNA-FISH). Heterosexual women with optimal vaginal microbiota self-collected vaginal specimens twice daily for 60 days or until iBV development (Nugent score 7-10 on ≥4 consecutive specimens). Women who developed iBV were matched to healthy controls by age, race, and contraceptive method. Gardnerella spp., P. bivia, and F. vaginae were quantified using PNA-FISH 2 days pre-iBV, the day of iBV, and 2 days post-iBV across five optical layers (z, z + 2, z + 4, z + 6, and z + 8 μm). Total counts of all three bacterial species were significantly higher on the day of iBV compared to 2 days pre-iBV (P = 0.011) and remained elevated 2 days post-iBV. Across most layers and time points, pooled mean Gardnerella spp. counts were significantly higher than F. vaginae counts (P ≤ 0.022-0.0003). On the day of iBV and 2 days post-iBV, pooled mean counts of Gardnerella spp. and F. vaginae progressively increased across most biofilm layers (P ≤ 0.043-0.0012). Controls had significantly lower counts of Gardnerella spp. and F. vaginae. P. bivia had low counts in all specimens. During the critical time period surrounding iBV, Gardnerella spp. are abundant throughout the developing biofilm and facilitate F. vaginae incorporation at later time points and higher biofilm layers. Additional research, including other Prevotella spp., is needed.IMPORTANCEBacterial vaginosis (BV) is the most common vaginal infection in reproductive-age women worldwide with a global prevalence of 30%. Recurrence rates can be up to 60% within 1 year of treatment. While BV is characterized as a polymicrobial biofilm infection, the exact etiology remains unknown. The BV biofilm may persist after antibiotic treatment, possibly due to incomplete eradication by current antimicrobial therapies, contributing to recurrent infection. Data are limited in evaluating the spatial formation of the BV biofilm around the time of incident BV. Providing a better understanding of this critical time period in incident BV pathogenesis is necessary to inform the development of prevention methods aimed at inhibiting biofilm formation and improving long-term treatment outcomes.

RevDate: 2026-01-22

Baborski A, Rohland O, Wuenschmann T, et al (2026)

Biofilm-derived bile duct microbiota in liver transplantation: high-quality genomes of Klebsiella pneumoniae, Enterococcus faecalis, and Enterococcus faecium.

Microbiology resource announcements [Epub ahead of print].

We present draft genomes of Klebsiella pneumoniae (K. pneumoniae), Enterococcus faecalis (E. faecalis), and Enterococcus faecium (E. faecium) isolated from a bilioenteric catheter after liver transplantation. Genome sizes were 5.58 Mb, 2.95 Mb, and 2.78 Mb, with G+C contents of 57.25%, 37.6%, and 37.99%, respectively, highlighting biofilm-associated bile duct colonizers.

RevDate: 2026-01-21

Jayasekara LACB, Watchaputi K, Butkinaree C, et al (2026)

Overcoming Candida albicans biofilm drug resistance via azole-sophorolipid synergy.

Scientific reports pii:10.1038/s41598-026-36278-8 [Epub ahead of print].

Antimicrobial resistance is a momentous global threat, demanding innovative approaches to combat drug-resistant pathogens. As a prevalent fungal pathogen, Candida albicans exhibits increasing resistance to conventional antifungals, especially the azoles. This study explores a novel approach combining sophorolipids (SLs), a glycolipid biosurfactant, with clinical azoles, including fluconazole (FLZ), itraconazole (ITZ), and ketoconazole (KCZ), against C. albicans biofilms. SLs from the yeast Starmerella riodocensis exhibited promising metabolic reduction and antibiofilm activity against Candida biofilms, with a biofilm inhibitory concentration (BIC50) of 512 mg/L. Among the tested azoles, ITZ exhibited the highest antibiofilm efficacy, prompting further investigation of SLs combinations. The ITZ-SLs combination markedly enhanced antibiofilm activity against preformed biofilms, with ITZ and SLs concentrations reduced by 16-fold and 4-fold, respectively, compared with their individual treatments (achieving a BIC50 of 1 mg/L ITZ and 128 mg/L SLs). Quantitative real-time polymerase chain reaction analysis revealed significant downregulation of essential biofilm-associated genes such as BCR1, EFG1, and CDC28, demonstrating SLs's ability to inhibit various stages of biofilm development and stability. Thus, the synergy observed with azole drugs, particularly ITZ and SLs, was highly effective in biofilm removal, highlighting the compatibility of anti-biofilm biosurfactant SLs with some antifungal agents.

RevDate: 2026-01-21

Wang X, Wang X, Bao Z, et al (2026)

Gelatin-based injectable hydrogel with dual ROS generation and biofilm disruption for infected wound healing.

International journal of biological macromolecules pii:S0141-8130(26)00325-9 [Epub ahead of print].

Chronic wounds present a major clinical challenge due to methicillin-resistant Staphylococcus aureus (MRSA) biofilm formation. Here, we developed an injectable gelatin-based hydrogel (Pgel-EGCG-DMY) with dynamic spatiotemporal antibacterial activity. By integrating epigallocatechin gallate (EGCG) and dihydromyricetin (DMY), the hydrogel enabled pH-responsive release, synergistically induces reactive oxygen species (ROS) generation and MRSA biofilm disruption. The hydrogel exhibited robust mechanical property, self-healing ability, and achieved>90% antibacterial efficacy against MRSA via combined ROS induction and gene expression (lrgA/B, mprF, narK/nasA, and saeR/S). In vivo, it accelerated tissue repair by downregulating pro-inflammatory cytokines (TNF-α, IL-1β), upregulating anti-inflammatory factors (IL-10, TGF-β), and promoting angiogenesis. This intelligent hydrogel platform offers a promising strategy for treating drug-resistant wound infections.

RevDate: 2026-01-21

Baird R, Gogoi D, Forde L, et al (2026)

Inhibition of Pseudomonas aeruginosa biofilm formation by peptidyl-arginine deiminases 2 and 4.

Journal of innate immunity pii:000550256 [Epub ahead of print].

Pseudomonas aeruginosa (P. aeruginosa) is a significant pathogen associated with chronic infections, particularly in immunocompromised individuals. Its ability to form biofilms, combined with antibiotic resistance, plays a critical role in the persistence of these infections. Peptidyl-arginine deiminases (PADs), including PAD2 and PAD4 isoforms, are involved in neutrophil phagocytic killing of P. aeruginosa. The aim of this study was to investigate the impact of PAD enzymes on biofilm development and virulence factor production by P. aeruginosa, with focus on the multidrug resistant strain, PGO2330. Crystal-violet biofilm assays and confocal scanning laser microscopy were employed to assess the effects of PADs on biofilm formation. Cell motility assays, qPCR for quorum sensing (QS) gene expression and QS-related virulence factor assays were performed. This study reports that 20 nM of PAD2 and PAD4 reduced PGO2330 biofilm formation to 67.9±5.6% (p=0.0002) and 68.2±4.2% (p=0.0002), respectively. This effect was likely due to PAD2 and PAD4 reducing PGO2330 surface attachment (p<0.0001) and twitching motility (p<0.0001 and p=0.0190, respectively). PGO2330 exposed to PAD2 and PAD4 showed reduced lasR, lasI, rhlR, rhll and mvrf gene expression and reduced levels of extracellular DNA, rhamnolipid, pyocyanin and protease activity. Overall, the results revealed that in addition to inhibiting P. aeruginosa biofilm formation, PADs decrease the production of QS-related virulence factors, advancing knowledge of the antimicrobial properties of PAD enzymes and supporting further research into the development of PAD-based therapeutics.

RevDate: 2026-01-21
CmpDate: 2026-01-21

Omelchenko O, Gutiérrez AV, Diaz M, et al (2026)

Evolved populations of Listeria monocytogenes related to biofilm formation and biocide stress in the context of food production environment niches.

Microbial genomics, 12(1):.

Cleaning and disinfection of food production environments (FPE) are fundamental components of food safety programmes designed to control microbial pathogens and prevent food contamination. Yet, FPE can still harbour foodborne pathogens, including Listeria monocytogenes, a significant concern to food manufacturers and health authorities due to the high mortality rate associated with invasive listeriosis. Mechanisms contributing to L. monocytogenes persistence in FPE include biofilm formation and reduced susceptibility to biocides, such as benzalkonium chloride (BC), for which several mechanisms are known. We hypothesized that prolonged exposure to disinfectants and other FPE-associated stressors would drive L. monocytogenes adaptation, resulting in the accumulation of genetic mutations linked to biofilm formation and reduced biocide susceptibility. To test this, we developed a biofilm persistence model, which studied 30 consecutive passages of biofilm-associated cells grown on stainless steel under sub-inhibitory BC concentrations. Whole-genome sequencing of evolved populations identified mutations that were associated with biofilm lineages and/or BC exposure. Non-synonymous mutations were identified in genes and pathways involved in metal homeostasis, stress response and pyrimidine biosynthesis. In addition, reduced susceptibility to BC arose through multiple independent mutations within the fepRA operon, encoding FepR transcriptional repressor and FepA MATE efflux pump. These mutations were observed across both planktonic and biofilm lifestyles, resulting in a comparable level of reduced susceptibility to BC in both states. Several loci with fixed mutations associated with biofilm lineages were identified, including the ykoK riboswitch leader, the pyrimidine synthesis operon and the stress response-related gene rsbU. Collectively, these findings provide new insights into the genetic mechanisms underlying L. monocytogenes biofilm persistence and reduced biocide susceptibility in the context of FPE and reveal novel targets potentially exploited by L. monocytogenes to establish and maintain niches in unfavourable environments.

RevDate: 2026-01-21

Zaidi S, Srivastava N, Ghosh M, et al (2026)

Anti-biofilm and anti-virulence activity of a rare actinobacteria Nocardia sp. EMB45 against Pseudomonas aeruginosa.

Archives of microbiology, 208(3):145.

RevDate: 2026-01-21
CmpDate: 2026-01-21

Moisés LS, Viotto HEDC, Coelho SRG, et al (2026)

Biofilm formation of mixed Candida albicans and methicillin-sensitive Staphylococcus aureus and surface properties of a 3D-printed denture base resin under different printing parameters.

Journal of applied oral science : revista FOB, 34:e20250526 pii:S1678-77572026000100603.

OBJECTIVE: To evaluate the formation of mixed-species biofilms of Candida albicans and methicillin-sensitive Staphylococcus aureus (MSSA) on the surface of a 3D-printed denture base resin, as well as its surface properties, under varying printing parameters.

METHODOLOGY: Discs (n=40 per group, 10×1.2 mm) of a denture base resin (priZma 3D Bio Denture) were fabricated using two 3D-printers-Liquid Crystal Display (LCD) and Digital Light Processing (DLP)-at three different angles (0°, 45°, or 90°). Surface roughness was measured using a digital profilometer and expressed as Ra (µm). For surface energy (SE) analysis, contact angles were measured using a tensiometer. Discs were incubated at 37 °C for 90 minutes and 48 hours to enable biofilm formation using C. albicans and MSSA inocula. Cell viability was assessed by colony-forming unit (CFU/mL) counts, and metabolic activity was evaluated using the XTT assay (absorbance). Microbial counts and XTT results were analyzed by three-way ANOVA (printer type, printing angle, incubation period). Surface roughness was analyzed by two-way ANOVA (printer type, printing angle), with Tukey's test and a significance level of 0.05.

RESULTS: For both CFU/mL and XTT assays, incubation period was the only significant factor (p<0.001 and p=0.006, respectively), while other factors and interactions were not statistically significant (p>0.05). Surface roughness was significantly influenced by printer type, printing angle, and their interaction (p=0.027). The LCD 0° and LCD 90° groups produced smoother surfaces compared with LCD 45° (p=0.002), which showed similar values to all DLP groups regardless of angle (p>0.05). The DLP printer did not show significant roughness variations across the tested angles (p>0.05). The LCD groups presented numerically lower SE values compared to the DLP groups.

CONCLUSION: The LCD system performs better than DLP in reducing surface roughness at 0° and 90°. Moreover, the analyzed factors did not significantly affect microbial adhesion or the formation of mixed-species biofilms.

RevDate: 2026-01-21

Hou CY, Lin YT, Wu JS, et al (2026)

Application of combining microbubbles with sanitizers to inactivate biofilm on stainless steel and polyvinyl chloride.

Journal of applied microbiology pii:8435311 [Epub ahead of print].

AIMS: Biofilm is a continuing issue of food microbial safety. This study combined microbubble (MB) with 50 mg/L sodium hypochlorite (NaClO) or chlorine dioxide (ClO2) to inactivate the biofilms of Salmonella Typhimurium and Staphylococcus aureus on stainless steel (SS) and polyvinyl chloride (PVC).

METHODS AND RESULTS: The biofilms were treated with the combinations of MB and NaClO (NMB) or ClO2 (CMB). After 10-min treatment, populations of S. Typhimurium on SS were below the detection limit (1.1 log CFU piece-1) for NMB and 2.6 log CFU piece-1 for CMB; the populations on PVC were 1.6 and 3.3 log CFU piece-1 for NMB and CMB, respectively. For S. aureus, 7.5-min NMB and CMB treatments reduced the populations on SS to below the detection limit and 1.6 log CFU piece-1, respectively; and to 1.3 log CFU piece-1 on PVC. Compared with water washing and sanitizers alone, NMB and CMB obtained an additional 5 to 6 log reductions. Higher residual populations of both bacteria were obtained on PVC, and S. Typhimurium had higher residual populations on both surfaces. Observation under a scanning electron microscope revealed that no biofilm remained on the NMB-treated SS and PVC pieces, but biofilm remained on the NaClO and water-treated pieces. Furthermore, calcofluor white staining confirmed that NMB treatment achieved the greatest removal of extracellular substances.

CONCLUSION: This is the first study showing that the combinations of MB and sanitizers inactivate the biofilm of these two bacteria on SS and PVC and demonstrate the potential for application in the food industry.

RevDate: 2026-01-21

da Silva Barbosa G, Rodrigues de Sousa B, de Oliveira Ferro L, et al (2026)

Anti-Sporothrix brasiliensis potential and anti-biofilm activity of Psidium guajava L. hydroacetone extract.

Natural product research [Epub ahead of print].

Sporothrix brasiliensis is the primary cause of sporotrichosis in Brazil. Reports of therapeutic failures with itraconazole treatment exist. We evaluated the antifungal activity of the hydroacetone extract of Psidium guajava in planktonic cells and biofilms of S. brasiliensis. The extract was obtained from the leaves, and high-performance liquid chromatography was performed. Broth microdilution tests were performed according to the CLSI M38. The strains were subjected to biofilm formation, and the antifungal activity of the extract against a strong producer strain was determined. The extract inhibited planktonic cells with minimum inhibitory concentrations (MICs) of ≤ 2 to 8 µg/mL. The metabolic activity of the strain with strong biofilm formation was inhibited with MICs of 16 and 32 µg/mL. The anti-Sporothrix activity of the hydroacetone extract of P. guajava serves as a basis for future studies for developing new drugs for the treatment of sporotrichosis.

RevDate: 2026-01-21
CmpDate: 2026-01-21

Silva Urco SE, Miguel Soto SY, Olaechea Alejo RM, et al (2025)

[Edta concentration in the effectiveness of antimicrobial photodynamic therapy with curcumin on streptococcus mutans biofilm].

Revista cientifica odontologica (Universidad Cientifica del Sur), 14(1):e277.

OBJECTIVE: Evaluate the optimal concentration of ethylenediaminetetracetic acid (EDTA) in curcumin-mediated antibacterial photodynamic therapy (aPDT) with blue LED light on S. mutans biofilms.

MATERIALS AND METHODS: Biofilms of S. mutans grown on resin discs were used, exposed to two concentrations of EDTA (1% and 17%). The experimental groups included: negative control, positive control (chlorhexidine), 1% EDTA, 17% EDTA, 100 μM curcumin, 100 μM curcumin + 1% EDTA, and 100 μM curcumin + 17% EDTA, with and without exposure to blue LED light, except for the positive control. Bacterial viability was assessed by counting colony-forming units (CFU/ml) after treatment application. Data were analyzed using one-way ANOVA adjusted by a generalized linear model (GLM) (p < 0,05).

RESULTS: The groups treated with 100µM curcumin and 100 μM curcumin + 1% EDTA, activated with blue LED light, showed the greatest reduction in bacterial viability. The combination with 17% EDTA did not significantly enhance the effect of aPDT.

CONCLUSIONS: The addition of EDTA did not significantly enhance the activity of curcumin-mediated aPDT against S. mutans biofilms. The 1% EDTA concentration showed results comparable to the use of curcumin alone, suggesting that higher concentrations do not provide additional benefit.

RevDate: 2026-01-21
CmpDate: 2026-01-21

Ma A, Wang J, Song W, et al (2026)

Genetically engineered bacteria with jacketed biofilm for enhancing drug delivery into tumor.

Materials today. Bio, 36:102692.

Tumor-targeted bacteria have emerged as promising drug carriers due to their intrinsic motility and hypoxia-homing property. Therapeutic agents can be loaded onto the bacterial surface, enabling their active delivery into tumor tissues. However, premature drug release during systemic circulation-likely triggered by various physiological/physical factors-inevitably results in reduced efficacy or increased off-target toxicity. Here, we present a genetic engineering strategy that enables E. coli MG1655 (EC) to autonomously produce a biofilm "jacket" on its surface (termed MEC) by regulating the expression of the biofilm-associated Csg gene cluster. This biofilm coating markedly enhances drug adsorption (1.7-fold increase for the model drug indocyanine green, ICG) and effectively prevents off-target leakage during systemic circulation. Benefiting from its tumor-homing capability and biofilm-mediated protection, MEC can deliver substantially more ICG into tumor inner regions. In murine tumor models, MEC-mediated delivery achieves significantly enhanced intratumoral drug retention and photothermal efficacy in comparison with the wild-type bacterial carrier. This work demonstrates an effective tumor-targeted drug delivery strategy based on genetically engineered biofilm technology, offering a promising avenue for precision bacterial oncology.

RevDate: 2026-01-20
CmpDate: 2026-01-21

Namiki T, Takada K, Hayakawa S, et al (2026)

Candida Tropicalis Biofilm Formation Under Secondary Bile Salt Sodium Deoxycholate.

Current microbiology, 83(3):144.

Candida species are components of the normal intestinal microbiota and are under constant exposure to bacterial metabolites, including secondary bile salts. Secondary bile salts are produced by commensal bacteria in the intestine and not only affect lipid absorption through emulsification but also have great effects on other microorganisms. Here, we examined the effect of a secondary bile salt, sodium deoxycholate (NaDCA), on the formation of biofilms by Candida tropicalis. In contrast to C. albicans, C. tropicalis tended to maintain its absolute biofilm biomass and surface hydrophobicity in the presence of NaDCA. Fluorescent 3D microscopic imaging of the biofilm revealed that NaDCA treatment reduced filamentous projection to the top of the biofilm. RNA-seq analysis revealed that some genes, especially those associated with iron metabolism, were differentially expressed in NaDCA-treated C. tropicalis. Although NaDCA altered the appearance of C. tropicalis biofilms, analysis of the expression of key virulence factor genes encoding agglutinin-like sequences and candidalysin revealed that these genes were less affected by NaDCA in C. tropicalis than in C. albicans. High-iron exposure had a negative effect on C. tropicalis biofilm biomass. These results suggest a difference in the intestinal niche occupied by C. albicans and C. tropicalis according to the local availability of secondary bile salts.

RevDate: 2026-01-20

Özer NE, Niran B, Çalı A, et al (2026)

In-vitro evaluation of the effectiveness of various disinfection procedures in reducing biofilm formation on customized implant abutments of different designs.

Scientific reports pii:10.1038/s41598-025-26007-y [Epub ahead of print].

To investigate the effectiveness of 80% ethanol and 2% chlorhexidine gel in reducing Pseudomonas aeruginosa (P. aeruginosa) biofilm formation on different types of customized implant abutments, using the crystal violet staining method. Three types of implant abutments were tested: Ti-base, monoblock titanium, and zirconia hybrid abutment. A total of 84 abutments were prepared and divided into four groups for each abutment type (n = 7): negative control (no biofilm), positive control (biofilm, no disinfection), ultrasonic cleaning with 80% ethanol for 5 min, and immersion in 2% chlorhexidine gel for 10 min. All abutments were incubated with P. aeruginosa for 24 h. Biofilm formation was quantified using the crystal violet staining method, and bacterial adhesion was confirmed in the positive control group via scanning electron microscopy. Statistical analysis was performed using one-way ANOVA and Tukey's test. There was no significant difference in bacterial retention among the different abutment designs tested (p > 0.05). The analyses revealed that both cleaning methods significantly reduced biofilm formation in all abutment types (p < 0.05) but were not superior to each other (p > 0.05). Both ethanol- and chlorhexidine-based disinfection protocols were effective in reducing Pseudomonas aeruginosa biofilm formation on different abutment designs under in-vitro conditions.

RevDate: 2026-01-20

Wang R, Niu S, Y Jiang (2026)

Adsorption of heavy metals by biofilm-coated microplastics in aquatic environments: Mechanisms, isotherm and kinetic processes, and influencing factors.

The Science of the total environment, 1015:181388 pii:S0048-9697(26)00045-8 [Epub ahead of print].

Microplastics (MPs) and heavy metals (HMs) are pervasive co-contaminants in environmental systems, where their synergistic interactions may amplify ecological risks. Notably, biofilm-coated microplastics (B-MPs), ubiquitous in aquatic environments, exhibit distinct physicochemical properties that govern heavy metal (HM) adsorption behaviors. Despite a surge in research on B-MPs-mediated HM adsorption, mechanistic drivers, quantitative modeling, and multifactorial regulation are still lack of systematic elucidation. This critical review synthesizes current advances to systematically decode adsorption mechanisms, adsorption isothermal/kinetic models, hierarchical controls spanning biofilm traits, microplastic characteristics, metal properties, and environmental conditions. The difference in HM adsorption between by B-MPs and naked MPs (N-MPs) are also systematically discusses. Key findings reveal that electrostatic interactions and surface complexation generally dominate the adsorption of HMs onto B-MPs, with kinetics best described by pseudo-second-order models and isothermal processes fitting Freundlich or Langmuir models. Several key aspects necessitate further elucidation, including competitive adsorption phenomena and their interplay with microbial metabolic shifts in multimetallic systems, the influence of plastic-derived dissolved organic matter (DOM), dynamic adsorption processes during biofilm formation, and the repercussions of pH-induced alterations in biofilm architecture and extracellular polymeric substance (EPS) composition. By bridging current insights with environmental realism, this work identifies understudied knowledge-high-environmentally relevant research models, biofilm succession dynamics, long-term HM retention, multifactorial influencing effects, AI-assisted exploring approaches-that warrants prioritization in future research.

RevDate: 2026-01-20

Han X, Wang P, Zhang H, et al (2026)

Novel Regulatory Interplay between FtsH and Spo0A∼P in Bacillus cereus 0-9 Biofilm Formation: A Potential Target for Antibiofilm Strategies.

Journal of agricultural and food chemistry [Epub ahead of print].

The biofilm formation of Bacillus cereus brings new challenges to food hygiene control. We investigated the multifunctional role of FtsH, an ATP-dependent metalloprotease, in regulating biofilm formation and environmental adaptation in B. cereus 0-9. Through homologous recombination, we generated ΔftsH and related mutants, subsequently evaluating their biofilm production using crystal violet staining, colonial morphology, and sporulation capacity, respectively. Transcriptional analysis using luminescent reporter strains revealed that biofilm-associated genes (sipW and calY) are downregulated in a FtsH-dependent manner in the mutants. Our findings demonstrate FtsH modulates Spo0E protein stability (confirmed by Western blot) and consequently influences Spo0A phosphorylation levels. Thus, FtsH as a crucial regulator of both sporulation and biofilm formation in B. cereus 0-9, mirroring its function in Bacillus subtilis while differing from Bacillus anthracis. It provides novel insights into bacterial stress response mechanisms and offers potential applications for developing biofilm eradication strategies, thereby addressing critical disinfection challenges in food processing environments.

RevDate: 2026-01-20

Massano F, Afonso AC, Sousa M, et al (2026)

The action of selected monoterpenes as biofilm control agents and antibiotic resistance modifiers.

Biofouling [Epub ahead of print].

Multidrug-resistant bacteria in biofilms are a growing public health threat, due to their resistance to conventional antibiotics. Phytochemicals are attractive candidates because of their structural diversity and ability to potentiate antimicrobial activity. This study investigated the antibiofilm and resistance-modifying effects of two monoterpenes, menthol and linalool, alone and in combination with ten antibiotics, against Escherichia coli and Staphylococcus epidermidis. Menthol exhibited MIC and MBC of 800 µg/mL against E. coli and the same MIC against S. epidermidis, while linalool showed MICs of 800 µg/mL and 400 µg/mL, respectively. Combination assays revealed enhanced activity of erythromycin with both monoterpenes against E. coli and of amoxicillin with menthol against S. epidermidis, although sessile cells were largely unaffected. When applied individually, both monoterpenes caused a 3-log reduction in culturable E. coli biofilm cells. The overall findings highlight the antibiofilm activity of linalool and, particularly, menthol, supporting their role as antibiotic adjuvants against biofilm-associated infections.

RevDate: 2026-01-20

Prabhu PP, J Nambi Krishnan (2026)

Comprehensive assessment of photo-oxidative degradation and biofilm colonization on microplastic pellets in simulated marine environment.

Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering [Epub ahead of print].

Microplastics (MPs) have emerged as a noteworthy environmental concern due to their pervasive presence and potential ecological impact. This study investigates the degradation of three commonly used plastics-polyethylene (PE), polypropylene (PP), and Nylon-6 (N6) under artificial aging conditions mimicking natural sunlight exposure and chemical oxidation in seawater. MP pellets were exposed to varying concentrations of hydrogen peroxide (H2O2) in artificially simulated seawater with controlled temperature at 60 °C, 300 RPM agitation, and UV irradiation. The chemical, morphological, and physical changes in the MP pellets over a 160-h period was characterized with Attenuated Total Reflectance Fourier-Transform Infrared Spectroscopy (ATR-FTIR), Field Emission Scanning Electron Microscopy (FE-SEM), Stereomicroscopy, and Particle size analysis (PSA). The results indicate that the degradation patterns and mechanical stability of the plastics varied based on the polymer type and exposure conditions. The PE exhibited significant degradation characterized by the formation of hydroxyl and carbonyl groups along with surface roughening and mechanical instability. The PP showed less degradation compared to PE attributed to its higher melting point and UV stability. The N6 displayed intermediate degradation influenced by amide linkages and mechanical strength. Additionally, this study investigated the formation and characterization of biofilms on MP fragments under simulated marine conditions over a 305-day period. FE-SEM analysis revealed distinct morphologies of biofilm development and Crystal Violet staining quantified the biofilm biomass on the aged PE, PP, N6 pellets. Confocal microscopic analyses using Hoechst-33342 and AO/PI staining further elucidated biofilm composition, highlighting varied microbial densities and cell viability on MP surfaces. These observations contribute to the understanding of the complex processes governing microplastic degradation and emphasize the importance of considering environmental factors in evaluating plastic pollution.

RevDate: 2026-01-20

Anonymous (2026)

Correction to: 4-Ethoxybenzoic acid interferes with the spatiotemporal dynamics of Staphylococcus aureus ATCC 6538 biofilm formation.

Journal of applied microbiology, 137(1):.

RevDate: 2026-01-19

Subramaniyan Y, Megha KS, Adithyan K, et al (2026)

Effect of metabolites on the survival and biofilm formation of Pantoea piersonii (Basionym: Kalamiella piersonii) in synthetic urine media.

BMC microbiology pii:10.1186/s12866-025-04684-z [Epub ahead of print].

RevDate: 2026-01-19

Sana SS, Mishra V, Vadde R, et al (2026)

Curcuma longa debranched starch assisted synthesis of cerium oxide nanoparticles and its antioxidant, anticancer, antimicrobial, and anti-biofilm activities.

Scientific reports pii:10.1038/s41598-026-35249-3 [Epub ahead of print].

Nowadays, there is a growing emphasis on eco-friendly methods for synthesizing metal nanoparticles (NPs), that avoid chemical processes and the production of harmful substances. In this study, we present a novel green approach for preparing cerium oxide nanodots (CeO2NPs) using Curcuma longa debranched starch as a reducing and capping agent via the sol-gel method. The prepared CeO2NPs were characterized using various techniques, including UV-vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and zeta potential (ζ). An absorption peak of the particles at 315 nm was detected in the UV-Vis spectrum. Spherical CeO2NPs were observed by SEM and TEM with a 2-4 nm NP range. Energy-dispersive X-ray spectroscopy (EDX) analysis showed that the Ce, oxygen and carbon contents were 68.33 wt%, 25.59 wt and 6.07 wt%, respectively. The CeO2NPs exhibited antioxidant activity with an IC[50] value of 3.2 ± 0.23 µg/mL, and 3.66 ± 0.18 µg/mL for DPPH and ABTS free radical scavenging assays, respectively. Furthermore, CeO2NPs exhibited antibacterial activity against Corynebacterium diphtheriae, Klebsiella pneumoniae, Salmonella typhi, and Escherichia coli and antibiofilm activity against Corynebacterium diphtheriae and Escherichia coli. The in vitro cytotoxicity of CeO2NPs against HepG2 cells (IC[50] of 178 ± 14 µg/mL) was dose-dependent as evaluated using the MTT assay. These results collectively suggest the diverse functions of CeO2NPs, showcasing their potential as antioxidants, anticancer and antibacterial agents, and their usefulness in biomedical applications.

RevDate: 2026-01-19

Mekureyaw MF, Pandey C, Sorty AM, et al (2026)

Biofilm formation by Pseudomonas putida KT2440 contributes to improve tomato drought stress resilience and priming for enhanced gene regulation.

Journal of plant physiology, 317:154704 pii:S0176-1617(26)00017-9 [Epub ahead of print].

Pseudomonas putida KT2440 is a plant growth-promoting rhizobacterium (PGPR), known to enhance tolerance to pathogen infection, but its role in drought stress mitigation remains largely unexplored. This study aimed to assess whether inoculation with KT2440 improves tomato tolerance to drought. Inoculation with the KT2440 wild type (WT) significantly improved ecophysiological drought stress responses by increasing leaf water potential and photosynthetic rate. It also resulted in an impact on the holobiont cell physiology through modulation of the activity signature of key enzymes of carbohydrate (e.g., PGM and vacInv) and antioxidant (e.g., GR, MDHAR, and cwPOX) metabolism under drought conditions. To functionally assess the role of biofilm formation in drought response, biofilm-deficient mutants KT2440 Alg, with only one gene cluster for the exopolysaccharide alginate deleted, and KT2440 Q, with four exopolysaccharide gene clusters (alg, bcs, pea and peb) deleted, were used. Inoculation with these two mutants led to reduced drought resilience, with partial or complete loss of protective effects in the Alg and Q mutants, respectively. This was reflected in lowered leaf water potential, photosynthetic rate, and reduced antioxidant and carbohydrate metabolism enzyme activities compared to inoculation with the corresponding wild type. Global RNA sequencing revealed that under drought conditions 360 % more genes were differentially regulated in the presence of KT2440 WT compared to the mock inoculated control, whereas this value decreased again to only 140 % more differentially regulated genes after recovery from the drought stress. Thus, KT2440 specifically primes the plant for a much more pronounced transcriptional response only during the impact of drought, thus providing resilience protection on demand. This priming for enhanced abiotic stress responsiveness was partially dependent on the ability to form biofilm. Both under well-watered and drought stress the number of differentially regulated genes was strongly reduced in plants inoculated with KT2440 Q compared to WT. Gene ontology and expression analyses showed significant upregulation of pathways involved in photosynthesis, phytohormone signaling, antioxidant metabolism, and drought resilience in KT2440-inoculated plants. Although KT2440 WT showed higher biofilm formation compared to the Alg and Q mutants, the strains did not differ in their ability for root colonization. These findings provide novel insights into the contribution of biofilm formation to PGPR-mediated drought tolerance and protection on demand via priming for enhanced transcriptional regulation under stress, supporting the potential of KT2440 for environmentally friendly mitigating of drought stress responses in crops.

RevDate: 2026-01-19

Bao X, Li B, Wang Y, et al (2026)

The CpxA/R system mediates the regulation of TolC on biofilm formation by extraintestinal pathogenic Escherichia coli in response to medium osmolarity.

Journal of applied microbiology pii:8429791 [Epub ahead of print].

AIMS: Hyperosmolarity is widely used for food preservation by inhibiting bacterial survival and growth. Therefore, it is of great significance to reveal bacterial osmotic-response mechanism. Biofilm formation presents a significant challenge for the control and prevention of pathogenic bacteria. Our previous study showed that inactivation of the efflux protein TolC in extraintestinal pathogenic Escherichia coli (ExPEC) decreased biofilm formation by affecting curli production in a medium osmolarity-dependent manner. This study aims to explore the role of the two-component CpxA/R system in mediating TolC regulation of ExPEC biofilm formation in response to osmolarity.

METHODS AND RESULTS: Various mutants derived from the parental ExPEC ΔtolC strain were constructed, and their abilities to form biofilms and produce curli fimbriae in different osmotic media were evaluated using crystal violet staining, scanning electron microscopy, Congo red assay, and real-time quantitative PCR. The results showed that the disruption of CpxA/R system by deleting the gene encoding histidine kinase-CpxA or response regulator-CpxR, or by introducing a point mutation at the phosphorylation site of CpxA, significantly compromised the effect of TolC inactivation on ExPEC biofilm formation and curli biosynthesis under both NaCl- and sucrose-induced osmotic stresses.

CONCLUSIONS: Our study firstly demonstrate that the CpxAR system mediated the regulation of TolC inactivation on ExPEC biofilm formation and curli production in response to both NaCl- and sucrose-induced osmotic stresses. These findings expand the regulatory network of bacterial biofilm formation and osmotic-responsiveness, contributing to exploring potential targets for preventing and controlling pathogenic bacteria.

RevDate: 2026-01-19

Yu F, Wang M, Hu J, et al (2026)

RatA regulates growth, biofilm formation, motility, and virulence in avian pathogenic Escherichia coli.

Journal of applied microbiology pii:8429785 [Epub ahead of print].

AIMS: Avian pathogenic Escherichia coli (APEC) causes colibacillosis, incurring significant economic losses. Toxin-antitoxin (TA) systems regulate bacterial virulence, biofilm formation, and antibiotic resistance. This study focuses on RatA, a toxin characterized as a ribosomal large subunit from our Tn5 transposon mutant library biofilm screen. In the clinical isolate APEC81, ratA is co-transcribed with its putative antitoxin gene, ratB, in the ratAB operon. This study aims to characterize the function of ratA in APEC and determine if ratB affects its regulation.

METHODS AND RESULTS: We found that deletion of ratA (ΔratA and ΔratAB) significantly impaired bacterial growth, biofilm formation, and motility, while deletion of the antitoxin gene ratB had no observable effect, indicating that RatA acts independently of RatB in modulating these traits. Further analysis identified four key active sites (V34, W103, F117, F147) essential for RatA binding to coenzyme Q. Mutating these sites recapitulated the ΔratA phenotype, confirming their functional importance.In host-pathogen interactions assays, the ΔratA mutant exhibited markedly reduced adhesion and invasion in HD-11 macrophages, diminished colonization in murine tissues, and a weakened capacity to provoke host inflammatory responses.

CONCLUSION: Studies demonstrate RatA as a central virulence factor in APEC, governing multiple pathogenic traits-from bacterial fitness to host interaction. These results underscore the potential of ratA as a target for anti-virulence strategies against APEC infections.

RevDate: 2026-01-19
CmpDate: 2026-01-19

Bahkali NA, Lambarte RNA, Sumague TS, et al (2025)

Busulfan inhibits Pseudomonas aeruginosa growth and reduces biofilm biomass and pyocyanin production.

Frontiers in cellular and infection microbiology, 15:1721773.

BACKGROUND: Pseudomonas aeruginosa remains a serious threat in clinical settings, especially among patients who are immunocompromised, receiving chemotherapy, or in intensive care units. With the rise of antibiotic resistance, drug repurposing offers a promising alternative strategy. Busulfan, an anticancer alkylating agent that induces DNA cross-linking and cytotoxic effects in cancer cells, may exert similar effects on microorganisms, as reported for other alkylating agents.

METHODS: This study evaluated the antibacterial potential of busulfan against P. aeruginosa. Initially, the antimicrobial activity of busulfan was assessed using the microdilution method, followed by investigations of key virulence factors of the PAO1 strain after treatment.

RESULTS: Busulfan inhibited bacterial growth in a dose-dependent manner, with 84% inhibition observed at 108 μg/mL, whereas bactericidal activity was only observed at much higher concentrations (MBC >512 and <1,024 μg/mL). Busulfan significantly reduced biofilm formation by 55%, decreased live-cell viability by 67% as observed using confocal laser scanning microscopy (CLSM), decreased pyocyanin production by 57%, and impaired iron chelation by 25%. Moreover, moderate synergy with gentamicin was observed at higher concentrations of busulfan. However, treatment with 108 μg/mL busulfan showed no effect on PAO1 hemolysis or motility.

CONCLUSION: Overall, busulfan demonstrates antimicrobial activity against P. aeruginosa, particularly through its effects on virulence factors. These preliminary results support the potential value of busulfan for repurposing, although further studies are needed to clarify its mechanism and therapeutic relevance.

RevDate: 2026-01-19
CmpDate: 2026-01-19

Tang Y, Xu Z, Li C, et al (2026)

Inhibition of Growth and Biofilm Formation in Staphylococcus aureus by LLY-507.

ACS omega, 11(1):2021-2033.

The emergence of methicillin-resistant Staphylococcus aureus (MRSA) as a prevalent antibiotic-resistant pathogen underscores the urgent need for novel antibacterial agents. This study investigates the potential of LLY-507 against Gram-positive bacteria, particularly S. aureus, focusing on its antibacterial and antibiofilm properties. Here, our data exhibited the favorable antibacterial activity of LLY-507 with MIC50 and MIC90 values of 25 μM against S. aureus. Additionally, LLY-507 at sub-MIC concentrations effectively reduced the planktonic growth and biofilm formation of S. aureus. Proteomic analysis of S. aureus treated with LLY-507 revealed the classification of the functional proteins with significant expression level alterations in bacterial metabolism, particularly amino acid biosynthesis. Furthermore, we demonstrated the disruption of S. aureus cell integrity by LLY-507 through scanning electron microscopy (SEM) assay, membrane permeability assays, and direct binding experiments between LLY-507 and cardiolipin. Lastly, the effectiveness of LLY-507 was proven in vivo using the Galleria mellonella infection model. Overall, these findings highlight the promising antibacterial and antibiofilm activities of LLY-507 against S. aureus and provide insights into its mechanism of action, implicating its potential as a lead compound for developing novel antibacterial agents targeting Gram-positive bacteria.

RevDate: 2026-01-19
CmpDate: 2026-01-19

Mo D, Pan M, Wei Y, et al (2026)

Near-infrared light-driven photocatalytic reactive oxygen species-generating antibacterial and self-shrinking hybrid hydrogels for combating drug-resistant bacterial biofilm infection and accelerating wound healing.

Bioactive materials, 59:396-420.

The development of wound dressings with tunable antibacterial activity and controllable self-shrinkage remains an intractable medical task for treating drug-resistant bacterial biofilm-infected wounds. Herein, we prepared a near-infrared-light (NIR)-controlled hydrogel (Co-BOS@C/F Gel) using an oxygen vacancy (OV)-rich cobalt (Co)-doped bismuth oxysulfide (Co-Bi2O2-XS, Co-BOS) photocatalyst as the guest molecule and a hydrazide-modified chondroitin sulfate/aldehyde-terminated Pluronic F127 hydrogel (C/F Gel) as the host carrier. First, the two-dimensional Co-BOS photocatalysts were synthesized via a one-step liquid-phase ion-exchange method. Co doping decreased the band gap, increased the number of OVs, and promoted charge transfer. Co-BOS also exhibited excellent photothermal performance (η = 34.09 %) and strong photocatalytic reactive oxygen species (ROS)-generating ability. The Co-BOS@C/F Gel formed via a dynamic Schiff reaction showed good temperature sensitivity, adhesion, hemostasis, and electrical conductivity and unique NIR-light-driven self-shrinkage. It exhibited broad-spectrum antibacterial activity against various bacteria and eliminated 95 % of the methicillin-resistant Staphylococcus aureus (MRSA) biofilm using photothermal therapy/antibacterial photocatalytic therapy. Integrated transcriptomic analyses revealed that the Gel operates via multiple antibacterial mechanisms, including the regulation of oxidative stress pathways and metabolic networks. Furthermore, this Gel significantly promoted cell proliferation and migration. In a mouse model of MRSA biofilm-infected wounds, the Co-BOS@C/F Gel under NIR light adaptively covered irregular wounds, eliminated MRSA biofilms, and accelerated wound closure. Without NIR light, the gel effectively promoted collagen deposition and angiogenesis. This study provides an innovative "kill four birds with one stone" strategy to treat drug-resistant bacteria-infected wounds and promotes the application of hybrid hydrogels in the biomedical field.

RevDate: 2026-01-19
CmpDate: 2026-01-19

Hemmingsen LM, N Škalko-Basnet (2026)

Breaking biofilm barriers in skin wounds: Membrane-Active antimicrobials in an era of resistance.

Current research in pharmacology and drug discovery, 10:100249.

Chronic wounds remain a significant challenge for healthcare systems worldwide, placing a considerable burden on both patients and resources. Their management is further complicated by the persistence of biofilm-forming bacteria and an escalating problem of antimicrobial resistance, both of which restrict the effectiveness of conventional therapies. Antimicrobial compounds with a rapid onset of action and activity that is not solely dependent on bacterial metabolism represent promising alternatives for bacterial and biofilm eradication. Among these, membrane-active antimicrobials (MAAs), including antimicrobial peptides, peptidomimetics, and other membrane-disrupting compounds, constitute a particularly interesting group of agents. Recent investigations have revealed diverse mechanisms through which MAAs compromise biofilm integrity, ranging from permeabilization of bacterial membranes to interference with quorum sensing and extracellular polymeric substances. Furthermore, pharmaceutical innovations such as nanoparticle-based carriers, hydrogel matrices, and scaffold-based delivery systems have shown potential to enhance MAA stability, optimize and prolong release profiles, improve antimicrobial and anti-biofilm efficacy, increase tissue penetration, and mitigate cytotoxicity concerns. By integrating insights from microbiology, materials science, and drug development, this short review aims to outline the challenges posed by biofilms in chronic wounds, appraise the antimicrobial and anti-biofilm activity of MAAs, and discuss how advanced delivery strategies might expand their clinical efficacy.

RevDate: 2026-01-19
CmpDate: 2026-01-19

Ababneh Q, Alawneh D, Jaradat Z, et al (2026)

Biofilm Formation in Clinical Acinetobacter baumannii Is Influenced by Isolate Source and Is Inversely Correlated With Antibiotic Resistance.

BioMed research international, 2026:9348199.

Acinetobacter baumannii is a troublesome bacterium that is highly prevalent in hospital settings, particularly in intensive care units (ICUs). Biofilm is one of the main virulence factors that makes A. baumannii a successful pathogen, enabling it to survive the harshest environments. This study aimed to corrolate the biofilm-forming capacity of clinical A. baumannii isolates with their antibiotic resistance phenotypes and isolation sources. A total of 327 clinical isolates originated from different hospitals, were recovered from diverse clinical specimens collected from patients admitted to the ICU and non-ICU wards. The isolates were characterized for their resistance phenotypes and biofilm formation capacities. Most A. baumannii isolates showed high resistance patterns against all examined antibiotics. Based on the resistance profiles, 81.2% and 12.3% of isolates were classified into extensively resistant (XDR) and multidrug-resistant (MDR), respectively. Moreover, the number of the ICU isolates exhibiting the XDR phenotype (86.7%) was higher than non-ICU XDR isolates (76.4%). The biofilm-forming capacity varied among the isolates, with most of the isolates forming either strong (44.3%) or weak biofilms (25.7%). Additionally, the fraction of ICU isolates with a strong capacity to form biofilms (60.7%, 91/150) was higher compared with the non-ICU isolates (30.5%, 54/177). We found a significantly higher tendency to form biofilms in isolates that are susceptible to 10 out of the 17 antibiotics (p = 0.014-0.002), including three carbapenems. In addition, a significant difference in the ability to form biofilms was revealed between the isolates originating from different hospitals and clinical specimens. Notably, a higher tendency to form biofilms was associated with susceptible strains isolated from blood (p = 0.024-0.04) and cerebrospinal fluid (p = 0.001-0.009). Our findings indicate that investigating the biofilm formation capacity of clinical A. baumannii strains could help identify patients requiring short or extended therapeutic treatments.

RevDate: 2026-01-19
CmpDate: 2026-01-19

Li X, Guo H, Hu G, et al (2026)

Exploring the antibacterial mechanism and biofilm inhibition of Plantago asiatica L. extract against Bacillus cereus with application in milk.

Current research in food science, 12:101298.

Plantago asiatica L. is an edible and medicinal plant with notable antibacterial activity. However, its antibacterial effects against Bacillus cereus have not yet been investigated. In this study, its extract exhibited a minimum inhibitory concentration (MIC) of 50 μg/mL against B. cereus ATCC 11778 and demonstrated effectiveness against antibiotic-resistant strains. Antibacterial activity, confirmed through growth kinetics and microscopy, was linked to cell membrane damage and disruption of genomic DNA and protein profiles. Beyond planktonic cells, the extract significantly combated biofilms, a key virulence factor, reducing biomass by over 77 % and key matrix components. Transcriptomic analysis provided mechanistic depth, revealing that the extract interfered with central metabolism, virulence, and membrane transport, and downregulated three key biofilm-related genes. This multi-faceted mechanism was validated in a practical food application, where 1 mg/mL of the extract completely inhibited bacterial growth in skim milk within 24 h. This study is the first to comprehensively demonstrate the dual antibacterial and antibiofilm efficacy of P. asiatica L. extract against B. cereus, establishing its potential as a novel, multi-targeted biointervention agent for the food industry.

RevDate: 2026-01-19
CmpDate: 2026-01-19

Herrera-Galindo J, Alcantara-Rosales CA, Ojeda OM, et al (2026)

Inactivation of Cysteine Synthase CysK-A enhances flocculation, biofilm formation, and sensitivity to oxidative stress in Azospirillum brasilense Sp7.

Biofilm, 11:100335.

Cysteine biosynthesis is a critical metabolic pathway for bacterial physiology. However, the full impact on the lifestyle of the plant-beneficial bacterium Azospirillum brasilense Sp7 is not completely understood. Our previous work identified a cysteine synthase A (CysK-A) as a key enzyme in cysteine synthesis in A. brasilense Sp7, but its inactivation did not lead to cysteine auxotrophy, suggesting functional redundancy in this type of enzyme. Here, we comprehensively characterized an A. brasilense AR cysK-A mutant, revealing a multifaceted phenotype that highlights the indispensable role of CysK-A. The cysK-A mutant exhibited a growth defect that was rescued by genetic and chemical complementation, underscoring the importance of de novo cysteine synthesis for optimal metabolic fitness. Furthermore, the cysK-A mutant displayed a striking hyper-aggregative behavior, characterized by significantly enhanced flocculation, biofilm formation, and exopolysaccharide production. Confocal microscopy revealed an abundance of ovoid, cyst-like cells. This transition toward a sessile lifestyle, induced by cysteine limitation stress, correlated with the intracellular accumulation of cyclic-di-GMP, as determined by a c-di-GMP biosensor assay. Additionally, the cysK-A mutant exhibited increased sensitivity to exogenous hydrogen peroxide stress, a deficiency that was restored by cysK-A complementation. The mutation also led to enhanced adhesion to radish seeds; however, it did not result in statistically significant differences in overall radish seedling colonization after seven days, possibly due to compensatory mechanisms. Collectively, our findings establish CysK-A as crucial for optimal growth, stress tolerance, and the regulation of aggregative behaviors in A. brasilense Sp7, providing insights into the adaptive strategies employed by this important plant-associating bacterium.

RevDate: 2026-01-19
CmpDate: 2026-01-19

Salazar-Sánchez A, Ghigo JM, Martínez-Ballesteros I, et al (2026)

Identification of biofilm-associated genes in Arcobacter butzleri.

Biofilm, 11:100344.

Arcobacter butzleri is an emerging zoonotic and foodborne pathogen isolated from human diarrhoeal samples and environmental sources. Despite its increasing clinical relevance, functional studies in this species have been limited by the lack of effective genetic tools. In this study, we report the first successful application of random transposon mutagenesis using the EZ-Tn5 transposome system in three A. butzleri strains. Transformation efficiency was found to be strain-dependent, with only one strain (P8) yielding enough mutants for phenotypic screening. A total of 56 mutants were characterised with 29 different disrupted genes, all exhibiting significantly reduced biofilm formation, and ten strains showing reduced or abolished motility. Furthermore, the phenotype of some mutants was also associated with lactate metabolism, methionine auxotrophy, cold sensibility and resistance to several antimicrobials. The identification of multiple independent insertions at identical nucleotide positions suggests possible insertional hotspots, although no conserved sequence motifs were identified. Overall, our findings provide novel insights into the gene functions associated with biofilm formation and other phenotypes in A. butzleri. This work not only represents a significant technical advancement for the genetic manipulation of this bacterium species but also establishes a foundation for future functional genomics studies aimed at elucidating the pathogenicity and environmental adaptability of A. butzleri.

RevDate: 2026-01-19
CmpDate: 2026-01-19

Wang YH, D'Amico I, Whalen J, et al (2026)

Experimental evolution in the cystic fibrosis chemical environment reveals early TCA cycle flux as a central regulator of Mycobacterium abscessus biofilm formation.

Biofilm, 11:100343.

Mycobacterium abscessus (MAB) is an emerging opportunistic pathogen that can cause severe, recalcitrant pulmonary infections in susceptible groups, including people with cystic fibrosis (CF). MAB forms biofilms during human infection and in environmental reservoirs such as household plumbing systems, and biofilm formation renders MAB more drug tolerant. However, our limited understanding of the regulatory systems governing mycobacterial biofilm formation undercuts our ability to disperse MAB biofilms and potentially increase treatment efficacy. Using experimental evolution, we demonstrate that selective pressure from synthetic cystic fibrosis sputum medium (SCFM1) drives the emergence of evolved MAB lineages that more readily aggregate in different environmental conditions. Whole-genome sequencing identified mutations in genes coding for two putative IclR family transcriptional regulators, which we named MraA and MraB, as responsible for the increase in aggregation. Using RNA-seq, we revealed that MraA and MraB share a regulon composed largely of genes involved in the early tricarboxylic acid (TCA) cycle and glutamate metabolism. Targeted metabolomic analysis confirmed that both mutants had increased levels of TCA cycle intermediates citrate/isocitrate and α-ketoglutarate (AKG), suggesting that in WT both MraA and MraB suppress flux through those metabolites. We found we could increase both citrate/isocitrate and AKG pools in WT MAB by supplementing SCFM1 with acetate, thereby increasing biofilm formation without increasing expression of the MraA/B regulon and demonstrating a specific causal relationship between those metabolites and biofilm formation. Finally, we show that acetate-induced, agar-suspended biofilms confer antibiotic tolerance. Altogether, we demonstrate how MAB carbon flux can be redirected by selective pressures in a CF sputum-like chemical environment to increase biofilm formation and drug tolerance. We propose a model in which MraA and MraB control flux of citrate/isocitrate/AKG and thereby feed into a metabolism-based biofilm regulatory system in MAB.

RevDate: 2026-01-19

Sengupta B, Alrubayan M, Kolla M, et al (2025)

AI-Based Detection of Optical Microscopic Images of Pseudomonas aeruginosa in Planktonic and Biofilm States.

Information (Basel), 16(4):.

Biofilms are resistant microbial cell aggregates that pose risks to the health and food industries and produce environmental contamination. The accurate and efficient detection and prevention of biofilms are challenging and demand interdisciplinary approaches. This multidisciplinary research reports the application of a deep learning-based artificial intelligence (AI) model for detecting biofilms produced by Pseudomonas aeruginosa with high accuracy. Aptamer DNA-templated silver nanocluster (Ag-NC) was used to prevent biofilm formation, which produced images of the planktonic states of the bacteria. Large-volume bright-field images of bacterial biofilms were used to design the AI model. In particular, we used U-Net with ResNet encoder enhancement to segment biofilm images for AI analysis. Different degrees of biofilm structures can be efficiently detected using ResNet18 and ResNet34 backbones. The potential applications of this technique are also discussed.

RevDate: 2026-01-18
CmpDate: 2026-01-18

Vadaga BS, Sharma S, Batchu R, et al (2026)

Unveiling the role of outer membrane proteins (OMPs) in biofilm formation and Harnessing them for targeting biofilm-forming bacterial infections.

World journal of microbiology & biotechnology, 42(2):49.

Biofilms are surface-attached bacterial consortia, which account for 80% of the world's microbial biomass, and are responsible for 75% of human infections. These surface bacterial communities have enhanced their ability to withstand unfavourable conditions and resist antimicrobial treatments due to the presence of outer membrane proteins (OMPs). Outer membrane proteins (OMPs) play a central role in biofilm formation by mediating adhesion, matrix assembly, and intercellular interactions, and they are increasingly being targeted for novel antibacterial therapies to disrupt biofilm-related infections. OMPs play a crucial role in biofilm formation, as these proteins contribute to the assembly and architecture of the biofilm matrix, interact with other matrix proteins, and influence surface hydrophobicity and cell aggregation. Notably, genetic modifications or deletions of OMPs can increase or decrease biofilm formation, indicating their regulatory influence on matrix composition and biofilm morphology. Incidentally, biofilm poses significant challenges in industry and abiotic medical equipment. OMPs offer excellent targets to mitigate biofilm-forming infections, since blocking their function can reduce bacterial adhesion and disrupt biofilm integrity. Furthermore, antimicrobial peptides as well as nanotechnology-based therapeutics are under development to target OMPs, allowing for innovative approaches that circumvent traditional resistance mechanisms seen in biofilms. This review underscores the significance of key OMPs in devising strategies to combat biofilm-associated infections and offers a concise overview of their structure, function, and immunoprotective role. By targeting outer membrane proteins, emerging therapies seek to address the persistence and antibiotic resistance of biofilm-forming bacteria, representing a promising direction in the treatment of chronic and multidrug-resistant infections.

RevDate: 2026-01-19

Chen F, Boylan D, Khan FZ, et al (2024)

Patterning Bacterial Cells on Quasi-Liquid Surfaces for Biofilm Morphological Control.

Advanced functional materials, 34(45):.

Bacterial cells within biofilms exhibit resistance to antibiotics, presenting persistent health risks. Current approaches to inhibit biofilm formation have limitations due to their poor biofilm morphological control. For instance, bactericidal surfaces suffer from the accumulation of dead cells that compromise their antibacterial efficacy, and existing antifouling surfaces fail to inhibit biofilm formation. In this work, exceptional biofilm suppression is achieved on quasi-liquid surfaces (QLS) with patterned surface chemistry where live bacterial cells are guided from slippery to sticky patterned destinations. These surfaces consist of 50 μm slippery and 10 μm sticky stripes. Live bacterial cells are directed to congregate on the sticky patterns, resulting in reduced biofilm biomass and surface coverage compared to uniform slippery surfaces. The patterned biofilm produces sparser extracellular matrix, thus reducing the barrier for antibiotic penetration and treatment. The innovative approach to direct cell migration on patterned QLS represents a promising strategy for inhibiting biofilm formation and combating biofilm-associated infections.

RevDate: 2026-01-18

Thakur V, Juneja A, Raza M, et al (2026)

Antimicrobial effects of four different probiotic compositions and delivery forms on clear aligner biofilm: A randomized single-blind crossover trial.

Journal of the World federation of orthodontists pii:S2212-4438(25)00828-8 [Epub ahead of print].

BACKGROUND: To evaluate the short-term antimicrobial effects of consumer probiotic formulations on bacterial load and biofilm accumulation on clear orthodontic aligners using a randomized four-period crossover design.

METHODS: Twenty Invisalign users completed four 7-day intervention periods separated by 14-day washouts. Interventions comprised: (1) probiotic gummy (Bonatona; Bacillus coagulans, 1.5 × 10⁹ CFU/dose), (2) probiotic rinse (Perfora; proprietary multi-strain blend, 1.5 × 10⁹ CFU/10 mL), (3) probiotic capsule (HealthKart; multi-strain, 3.0 × 10¹⁰ CFU/dose), and (4) probiotic drink (Yakult Original; Lacticaseibacillus paracasei Shirota, ∼6.5 × 10⁹ CFU/65 mL). Products were used as labelled; Labelled strains included Bacillus coagulans, Lacticaseibacillus paracasei Shirota, and proprietary multi-strain Lactobacillus/Bifidobacterium blends (10⁹-10¹⁰ CFU/dose). No independent verification of strain identity or viability was undertaken. After each period, 5-mm discs from standardized aligner sites were analysed for total viable counts (CFU/mL) and for biofilm matrix (EPS) and viability using confocal laser scanning microscopy (CLSM) with Concanavalin A staining. Primary analysis used linear mixed-effects models with treatment, period, and sequence as fixed effects and subject as a random intercept. Least-squares means (95 % CI) and Bonferroni-adjusted contrasts are reported. Trial registered at CTRI/2024/08/072820.

RESULTS: All four probiotic delivery forms produced significant reductions in total viable counts and EPS fluorescence compared with pre-intervention controls (P < 0.001). CFU reductions ranged from 0.62-1.06 log₁₀ (mean reduction 3.8-4.3 × 10³ CFU/mL), with the probiotic drink showing the largest decrease (LS-mean difference vs. baseline = 1.055 log₁₀ CFU; 95% CI: 0.93-1.18; P < 0.001). Similar reductions were observed in CLSM fluorescence (mean differences 93-145 AU; all P < 0.001).

CONCLUSIONS: Short-term use of consumer probiotics delivered as a drink, rinse, gummy, or capsule, demonstrated statistically significant antimicrobial reductions in aligner biofilm. The probiotic drink yielded the greatest effect. Given the short intervention duration and label-only verification of probiotic content, these findings should be interpreted as preliminary. Larger, species-resolved studies with longer follow-up and comparison against routine mechanical cleaning are needed before clinical recommendations can be established.

RevDate: 2026-01-18

Rocha IV, Martins LR, Pimentel MIS, et al (2026)

Post-pandemic molecular epidemiology of β-lactam resistance and biofilm formation in multidrug-resistant Acinetobacter baumannii from a Brazilian tertiary hospital.

Microbial pathogenesis pii:S0882-4010(26)00033-1 [Epub ahead of print].

BACKGROUND: Multidrug-resistant (MDR) Acinetobacter baumannii has emerged as a critical post-pandemic pathogen, combining antimicrobial resistance with biofilm formation, severely complicating infection control. We aimed to characterize the genetic mechanisms of β-lactams resistance and biofilm-forming capacity of MDR A. baumannii isolates from a Brazilian tertiary hospital, in the post-COVID-19 pandemic period.

METHODS: A. baumannii isolates were collected from various clinical specimens between 2023/2024. Species identification was performed using the Phoenix BD® system. Antimicrobial susceptibility testing was performed by broth microdilution. β-lactamase genes were investigated by PCR, and biofilm formation was quantified using crystal violet assay. Growth kinetics were analyzed spectrophotometrically.

RESULTS: Among 78 isolates, 98.7% exhibited MDR profiles while remaining susceptible to colistin. Strong biofilm production occurred in 71.8% of isolates, particularly from rectal swabs. Dominant resistance genes included blaOXA-23 (66.7%), blaOXA-24 (19.2%), and blaOXA-143 (12.9%), with blaNDM-1 in 3.9%. Isaba1 was associated with blaOXA-23 (44.2%) and blaADC (92.3%). The bap gene was detected in 28.2% of the isolates, while blaKPC/GES/IMP/SPM/PER-1 were absent. Biofilm-forming groups displayed distinct growth patterns.

CONCLUSION: Our study demonstrates that most A. baumannii isolates exhibit MDR profiles and robust biofilm formation. The widespread presence of β-lactamase genes and biofilm-producing strains underscores the necessity for enhanced molecular surveillance and biofilm-focused infection control measures in critical care units. These findings provide valuable insights into the genetic mechanisms driving resistance and biofilm formation in post-pandemic clinical settings. To mitigate the persistence and spread of high-risk MDR clones, hospitals should integrate genetic resistance profiling and biofilm-targeted strategies into infection control protocols.

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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 )