Various pathogens have the ability to grow on food matrices and instruments. This grow may reach to form biofilms. Bacterial biofilms are community of microorganisms embedded in extracellular polymeric substances (EPSs) containing lipids, DNA, proteins, and polysaccharides. These EPSs provide a tolerance and favorable living condition for microorganisms. Biofilm formations could not only contribute a risk for food safety but also have negative impacts on healthcare sector. Once biofilms form, they reveal resistances to traditional detergents and disinfectants, leading to cross-contamination. Inhibition of biofilms formation and abolition of mature biofilms is the main target for controlling of biofilm hazards in the food industry. Some novel eco-friendly technologies such as ultrasound, ultraviolet, cold plasma, magnetic nanoparticles, different chemicals additives as vitamins, D-amino acids, enzymes, antimicrobial peptides, and many other inhibitors provide a significant value on biofilm inhibition. These anti-biofilm agents represent promising tools for food industries and researchers to interfere with different phases of biofilms including adherence, quorum sensing molecules, and cell-to-cell communication. This perspective review highlights the biofilm formation mechanisms, issues associated with biofilms, environmental factors influencing bacterial biofilm development, and recent strategies employed to control biofilm-forming bacteria in the food industry. Further studies are still needed to explore the effects of biofilm regulation in food industries and exploit more regulation strategies for improving the quality and decreasing economic losses.

Cronobacter sakazakii, an opportunity foodborne pathogen, could contaminate a broad range of food materials and cause life-threatening symptoms in infants. The bacterial envelope structure contribute to bacterial environment tolerance, biofilm formation and virulence in various in Gram-negative bacteria. DsbA and PepP are two important genes related to the biogenesis and stability of bacterial envelope. In this study, the DsbA and PepP were deleted in C. sakazakii to evaluate their contribution to stress tolerance and virulence of the pathogen. The bacterial environment resistance assays showed DsbA and PepP are essential in controlling C. sakazakii resistance to heat and desiccation in different mediums, as well as acid, osmotic, oxidation and bile salt stresses. DsbA and PepP also played an important role in regulating biofilm formation and motility. Furthermore, DsbA and PepP deletion weaken C. sakazakii adhesion and invasion in Caco-2, intracellular survival and replication in RAW 264.7. qRT-PCR results showed that DsbA and PepP of C. sakazakii played roles in regulating the expression of several genes associated with environment stress tolerance, biofilm formation, bacterial motility and cellular invasion. These findings indicate that DsbA and PepP played an important regulatory role in the environment resisitance, biofilm formation and virulence of C. sakazakii, which enrich understanding of genetic determinants of adaptability and virulence of the pathogen.

Grey mould caused by Botrytis cinerea is a devastating disease responsible for large losses to agricultural production, and B. cinerea is a necrotrophic model fungal plant pathogen. Membrane proteins are important targets of fungicides and hotspots in the research and development of fungicide products. Wuyiencin affects the permeability and pathogenicity of B. cinerea, parallel reaction monitoring revealed the association of membrane protein Bcsdr2, and the bacteriostatic mechanism of wuyiencin was elucidated. In the present work, we generated and characterised ΔBcsdr2 deletion and complemented mutant B. cinerea strains. The ΔBcsdr2 deletion mutants exhibited biofilm loss and dissolution, and their functional activity was illustrated by reduced necrotic colonisation on strawberry and grape fruits. Targeted deletion of Bcsdr2 also blocked several phenotypic defects in aspects of mycelial growth, conidiation and virulence. All phenotypic defects were restored by targeted gene complementation. The roles of Bcsdr2 in biofilms and pathogenicity were also supported by quantitative real-time RT-PCR results showing that phosphatidylserine decarboxylase synthesis gene Bcpsd and chitin synthase gene BcCHSV II were downregulated in the early stages of infection for the ΔBcsdr2 strain. The results suggest that Bcsdr2 plays important roles in regulating various cellular processes in B. cinerea. KEY POINTS: • The mechanism of wuyiencin inhibits B. cinerea is closely associated with membrane proteins. • Wuyiencin can downregulate the expression of the membrane protein Bcsdr2 in B. cinerea. • Bcsdr2 is involved in regulating B. cinerea virulence, growth and development.

Multi-drug-resistant Staphylococcus aureus infections necessitate novel antibiotic development. D-3263, a transient receptor potential melastatin member 8 (TRPM8) agonist, has potential antineoplastic properties. Here, we reported the antibacterial and antibiofilm activities of D-3263. Minimum inhibitory concentrations (MICs) against S. aureus, Enterococcus faecalis and E. faecium were ≤ 50 µM. D-3263 exhibited bactericidal effects against clinical methicillin-resistant S. aureus (MRSA) and E. faecalis strains at 4× MIC. Subinhibitory D-3263 concentrations effectively inhibited S. aureus and E. faecalis biofilms, with higher concentrations also clearing mature biofilms. Proteomic analysis revealed differential expression of 29 proteins under 1/2 × MIC D-3263, influencing amino acid biosynthesis and carbohydrate metabolism. Additionally, D-3263 enhanced membrane permeability of S. aureus and E. faecalis. Bacterial membrane phospholipids phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and cardiolipin (CL) dose-dependently increased D-3263 MICs. Overall, our data suggested that D-3263 exhibited potent antibacterial and antibiofilm activities against S. aureus by targeting the cell membrane.

Microorganisms, including potential pathogens, can colonise plastic surfaces in aquatic environments. This study investigates the colonisation of plastic pellets by Escherichia coli (E. coli) as a proxy for faecal pathogens in aquatic environments. Plastic pellets from a polluted beach were placed in seawater aquaria spiked with E. coli. Diverse bacteria, primarily from the Proteobacteria phylum, rapidly colonised the pellets within 24 h, with notable species known for plastic or hydrocarbon degradation. Over 26 days, biofilms formed on the plastic surfaces, reaching bacterial populations of up to 6.8·105 gene copies (gc) of the 16S rRNA mm-2. E. coli, was detected in the pellets for up to 7 days using culture methods, exhibiting varying attachment densities regardless of source or environmental factors. The study highlights plastic biofilms as reservoirs for E. coli, contributing to the survival and persistence of faecal bacteria in aquatic systems. These findings deepen our understanding of the risks associated with plastic pollution in marine settings, offering insights into the behaviour of faecal indicators and their implications for water quality assessments, while providing valuable information on potential pathogen dissemination within plastic-associated microbial communities.

Oceanic facilities and equipment corrosion present considerable economic and safety concerns, predominantly due to microbial corrosion. Early detection of corrosive microbes is pivotal for effective monitoring and prevention. Yet, traditional detection methods often lack specificity, require extensive processing time, and yield inaccurate results. Hence, the need for an efficient real-time corrosive microbe monitoring technology is evident. Pseudomonas aeruginosa, a widely distributed microorganism in aquatic environments, utilizes its production of quinone-like compounds, specifically pyocyanin (PYO), to corrode metals. Here, we report a novel fiber optic surface plasmon resonance (SPR) sensor modified by the C-terminal of BrlR protein (BrlR-C), which is a specific receptor of PYO molecule, to detect P. aeruginosa in aquatic environments. The results showed that the sensor had a good ability to recognize PYO in the concentration range of 0-1 μg/mL, and showed excellent sensing performance in real-time monitoring the growth status of P. aeruginosa. With a strong selectivity of PYO, the sensor could clearly detect P. aeruginosa against other bacteria in seawater environment, and exhibited excellent anti-interference ability against variations in pH, temperature and pressure and other interfering substances. This study provides a useful tool for monitoring corrosive P. aeruginosa biofilm in aquatic environments, which is a first of its kind example that serves as a laboratory model for the application of fiber optic technology in real-world scenarios to monitoring biofilms in microbial corrosion and biofouling.

UNASSIGNED: Widespread opportunistic pathogens pose a serious threat to global health, particularly in susceptible hospital populations. The escalating crisis of antibiotic resistance highlights the urgent need for novel antibacterial agents and alternative treatment approaches. Traditional Chinese Medicine (TCM) and its compounds have deep roots in the treatment of infectious diseases. It has a variety of active ingredients and multi-target properties, opening up new avenues for the discovery and development of antimicrobial drugs.
UNASSIGNED: This study focuses on assessing the efficacy of the Shensheng-Piwen changed medicinal powder (SPC) extracts against opportunistic pathogen infections by broth microdilution and agar disc diffusion methods. Additionally, biofilm inhibition and eradication assays were performed to evaluate the antibiofilm effects of SPC extracts.
UNASSIGNED: Metabolite profiles were analyzed by LC-MS. Furthermore, the potential synergistic effect between SPC and Metal-Organic Framework (MOF) was investigated by bacterial growth curve analysis. The results indicated that the SPC extracts exhibited antibacterial activity against S. aureus, with a minimum inhibitory concentration (MIC) of 7.8 mg/mL (crude drug concentration). Notably, at 1/2 MIC, the SPC extracts significantly inhibited biofilm formation, with over 80% inhibition, which was critical in tackling chronic and hospital-acquired infections. Metabolomic analysis of S. aureus revealed that SPC extracts induced a notable reduction in the levels of various metabolites, including L-proline, L-asparagine. This suggested that the SPC extracts could interfere with the metabolism of S. aureus. Meanwhile, the growth curve experiment proved that SPC extracts and MOFs had a synergistic antibacterial effect.
UNASSIGNED: In conclusion, the present study highlights the potential of SPC extracts as a novel antibacterial agent against S. aureus infections, with promising biofilm inhibition properties. The observed synergistic effect between SPC extracts and MOFs further supports the exploration of this combination as an alternative treatment approach.

Vibrio parahaemolyticus possesses two distinct type VI secretion systems (T6SS), namely T6SS1 and T6SS2. T6SS1 is predominantly responsible for adhesion to Caco-2 and HeLa cells and for the antibacterial activity of V. parahaemolyticus, while T6SS2 mainly contributes to HeLa cell adhesion. However, it remains unclear whether the T6SS systems have other physiological roles in V. parahaemolyticus. In this study, we demonstrated that the deletion of icmF2, a structural gene of T6SS2, reduced the biofilm formation capacity of V. parahaemolyticus under low salt conditions, which was also influenced by the incubation time. Nonetheless, the deletion of icmF2 did not affect the biofilm formation capacity in marine-like growth conditions, nor did it impact the flagella-driven swimming and swarming motility of V. parahaemolyticus. IcmF2 was found to promote the production of the main components of the biofilm matrix, including extracellular DNA (eDNA) and extracellular proteins, and cyclic di-GMP (c-di-GMP) in V. parahaemolyticus. Additionally, IcmF2 positively influenced the transcription of cpsA, mfpA, and several genes involved in c-di-GMP metabolism, including scrJ, scrL, vopY, tpdA, gefA, and scrG. Conversely, the transcription of scrA was negatively impacted by IcmF2. Therefore, IcmF2-dependent biofilm formation was mediated through its effects on the production of eDNA, extracellular proteins, and c-di-GMP, as well as its impact on the transcription of cpsA, mfpA, and genes associated with c-di-GMP metabolism. This study confirmed new physiological roles for IcmF2 in promoting biofilm formation and c-di-GMP production in V. parahaemolyticus.

UNASSIGNED: Stenotrophomonas is a prominent genus owing to its dual nature. Species of this genus have many applications in industry and agriculture as plant growth-promoting rhizobacteria and microbial biological control agents, whereas species such as Stenotrophomonas maltophilia are considered one of the leading gram-negative multi-drug-resistant bacterial pathogens because of their high contribution to the increase in crude mortality and significant clinical challenge. Pathogenic Stenotrophomonas species and most clinical isolates belong to the Stenotrophomonas maltophilia complex (SMc). However, a strain highly homologous to S. terrae was isolated from a patient with pulmonary tuberculosis (TB), which aroused our interest, as S. terrae belongs to a relatively distant clade from SMc and there have been no human association reports.
UNASSIGNED: The pathogenicity, immunological and biochemical characteristics of 610A2T were systematically evaluated.
UNASSIGNED: 610A2T is a new species of genus Stenotrophomonas, which is named as Stenotrophomonas pigmentata sp. nov. for its obvious brown water-soluble pigment. 610A2T is pathogenic and caused significant weight loss, pulmonary congestion, and blood transmission in mice because it has multiple virulence factors, haemolysis, and strong biofilm formation abilities. In addition, the cytokine response induced by this strain was similar to that observed in patients with TB, and the strain was resistant to half of the anti-TB drugs.
UNASSIGNED: The pathogenicity of 610A2T may not be weaker than that of S. maltophilia. Its isolation extended the opportunistic pathogenic species to all 3 major clades of the genus Stenotrophomonas, indicating that the clinical importance of species of Stenotrophomonas other than S. maltophilia and potential risks to biological safety associated with the use of Stenotrophomonas require more attention.

UNASSIGNED: Conventional biofilters, which rely on bacterial activity, face challenges in eliminating hydrophobic compounds, such as aromatic compounds. This is due to the low solubility of these compounds in water, which makes them difficult to absorb by bacterial biofilms. Furthermore, biofilter operational stability is often hampered by acidification and drying out of the filter bed.
UNASSIGNED: Two bioreactors, a bacterial biofilter (B-BF) and a fungal-bacterial coupled biofilter (F&B-BF) were inoculated with activated sludge from the secondary sedimentation tank of the Sinopec Yangzi Petrochemical Company wastewater treatment plant located in Nanjing, China. For approximately 6 months of operation, a F&B-BF was more effective than a B-BF in eliminating a gas-phase mixture containing benzene, toluene, ethylbenzene, and para-xylene (BTEp-X).
UNASSIGNED: After operating for four months, the F&B-BF showed higher removal efficiencies for toluene (T), ethylbenzene (E), benzene (B), and para-X (p-Xylene), at 96.9%, 92.6%, 83.9%, and 83.8%, respectively, compared to those of the B-BF (90.1%, 78.7%, 64.8%, and 59.3%). The degradation activity order for B-BF and F&B-BF was T > E > B > p-X. Similarly, the rates of mineralization for BTEp-X in the F&B-BF were 74.9%, 66.5%, 55.3%, and 45.1%, respectively, which were higher than those in the B-BF (56.5%, 50.8%, 43.8%, and 30.5%). Additionally, the F&B-BF (2 days) exhibited faster recovery rates than the B-BF (5 days).
UNASSIGNED: It was found that a starvation protocol was beneficial for the stable operation of both the B-BF and F&B-BF. Community structure analysis showed that the bacterial genus Pseudomonas and the fungal genus Phialophora were both important in the degradation of BTEp-X. The fungal-bacterial consortia can enhance the biofiltration removal of BTEp-X vapors.