Search Results (1,573)

Objectives: Seawater-immersed burn wounds are highly susceptible to contamination, persistent inflammation, oxidative stress, and delayed healing, while current irrigation solutions remain suboptimal for such acute injuries. This study aimed to evaluate the therapeutic efficacy and underlying mechanisms of plasma-activated water (PAW) as a novel irrigation strategy for these complex wounds. Methods: The antibacterial efficacy of PAW against marine pathogens was first evaluated in vitro. Subsequently, a rat model of seawater-immersed burn injury was established in male Sprague-Dawley (SD) rats to assess the therapeutic effects of PAW irrigation on wound healing, infection control, and underlying biological mechanisms. Results: In vitro, PAW significantly eradicated two major marine pathogens, Vibrio vulnificus and Vibrio parahaemolyticus (p < 0.001). In vivo, PAW markedly accelerated wound closure, achieving complete healing in 23.60 ± 6.50 days vs. 38.67 ± 2.08 days (Normal saline group) and 58.33 ± 10.97 days (Model group) (p < 0.05). PAW significantly reduced bacterial burden, modulated inflammation by decreasing interleukin-6 and increasing interleukin-10, and alleviated oxidative stress, as evidenced by reduced malondialdehyde levels and enhanced superoxide dismutase activity. Histological evaluation demonstrated enhanced re-epithelialization, collagen deposition, and increased expression of vascular endothelial growth factor and platelet endothelial cell adhesion molecule-1. No adverse effects on serum biochemistry or major organ histopathology were observed. Conclusions: PAW may be a safe, promising, and multifunctional irrigation strategy that promotes seawater-immersed burn healing through coordinated antibacterial, anti-inflammatory, antioxidant, and pro-angiogenic effects, highlighting its strong potential for clinical translation. Full article

Listeria monocytogenes (Lm) is an important zoonotic foodborne pathogen that causes severe rhombencephalitis in ruminants. The trigeminal ganglion is a critical node for Lm invasion of the central nervous system via neural pathways. However, the roles of key virulence factors InlA, InlB, and LLO from ovine-derived Lm in trigeminal ganglion neuron infection remain unclear. In this study, LM90SB2, an ovine-derived Lm strain isolated from a sheep with encephalitis in Xinjiang, China, was used as the wild type, and its ΔInlAB double-gene deletion and ΔInlABO triple-gene deletion mutants were constructed. Primary mouse trigeminal ganglion cells (TGCs) were infected with these strains, and cell-association and invasion assays, bacterial colonization analysis, cell scratch tests, Western blotting, and qRT-PCR were performed to explore the effects of InlA, InlB, and LLO on Lm infection of TGCs and their regulatory roles in host adhesion molecules N-cadherin and NCAM1. The results showed that the wild-type LM90SB2 had significantly stronger cell-association, invasion, and colonization abilities in TGCs than the ΔInlAB and ΔInlABO mutants (p < 0.01 or p < 0.0001). LM90SB2 infection significantly upregulated the mRNA and protein expression levels of N-cadherin and NCAM1 in TGCs and enhanced TGC migration, while these effects were gradually attenuated with the sequential deletion of InlA, InlB and LLO. This study clarifies the synergistic roles of InlA, InlB, and LLO in mediating the infection of trigeminal ganglion neurons by ovine-derived Lm and reveals the molecular mechanism by which Lm promotes neural invasion by regulating the expression of host cell adhesion molecules. Our findings provide important experimental data for elucidating the neural invasion pathway of Lm in ruminants and lay a theoretical foundation for the development of targeted prevention and control strategies for ruminant listeriosis in veterinary clinical practices. Full article

Fusobacterium nucleatum (Fn) has emerged as one of the most extensively studied tumor-associated opportunistic pathogens in colorectal cancer (CRC). The central question in Fn–CRC research has shifted from species-level detection or enrichment toward identifying specific lineages with enhanced persistence and tumor-promoting potential under defined host and ecological contexts. Accumulating evidence suggests substantial heterogeneity within Fn at the subspecies and clade levels. Among these, the F. nucleatum subsp. animalis C2 (Fna C2) lineage has been proposed as a candidate high-risk clade with potentially greater adaptability to the gastrointestinal tract and tumor microenvironment. However, current support for Fna C2 is derived mainly from ecological enrichment, comparative genomics, inferred metabolic features, and limited functional observations, while direct clinical and mechanistic validation at the clade level remains limited. Fn has been implicated in CRC progression through multiple interconnected processes, including adhesion and colonization, host signaling activation, inflammatory amplification, immune suppression, and metabolic adaptation. Notably, these pathogenic outputs are unlikely to be uniformly distributed across all Fn lineages, but instead appear to be shaped by the combined influence of bacterial lineage, host molecular context, microbial community structure, and spatial organization within the tumor microenvironment. In this review, we summarize the lineage heterogeneity of Fn, its association with CRC, and the underlying host–pathogen interaction mechanisms. We further discuss implications for high-resolution stratification, risk classification, and clinical translation, emphasizing the need to move from species-level associations toward lineage-resolved and context-aware frameworks. Full article

Polyurethanes (PUs) are widely used in biomedical applications; however, their surface properties critically determine bacterial colonization and cell response. In this study, medical-grade PU films were modified using low-pressure C₃H₂F₄ plasma (50 W, 300 s, 0.2 mbar), and the resulting changes in surface chemistry, wettability, topography, bacterial adhesion, and cell compatibility were evaluated. X-ray photoelectron spectroscopy (XPS) analysis confirmed the incorporation of fluorine-containing groups (CF₂, CF₃) and the appearance of an F 1s signal at ~688.3 eV. Plasma treatment increased the water contact angle from 92.6° ± 5.6° to 97.9° ± 3.1° and elevated the root mean square (RMS) surface roughness (Sq) from 39.0 nm to 77.3 nm. Surface free energy slightly decreased after plasma treatment due to reductions in both polar and dispersive components. Quantitative adhesion assays revealed strain-dependent effects. For S. aureus DSM 4910, S. epidermidis DSM 28319, and P. aeruginosa DSM 22644, no consistent reduction in adhesion was observed on plasma-treated surfaces. In contrast, E. coli DSM 18039 demonstrated significantly higher adhesion on modified PU at all incubation times, reaching 5.96 ± 0.44 logCFU/mL after 240 min compared to 5.05 ± 0.27 log colony-forming units per milliliter (logCFU/mL) on unmodified PU. Fluorescence microscopy confirmed increased surface coverage by E. coli on fluorinated samples. Biocompatibility studies using A549 cells showed no cytotoxic effects. Cell spreading area remained comparable between surfaces (1188.6 vs. 1185.1 µm²; p = 0.958). However, cells on plasma-treated PU exhibited reduced major axis length (38.6 vs. 46.7 µm; p < 0.001) and decreased focal adhesion area (8.88 vs. 10.94 µm²; p = 0.002), indicating moderate alterations in cell morphology without compromised viability. These results demonstrate that C₃H₂F₄ plasma fluorination moderately increases PU hydrophobicity and nanoscale roughness, induces strain-dependent changes in bacterial adhesion—particularly enhancing E. coli colonization—while fully preserving mammalian cell viability and showing no cytotoxic effects of the modified surface. Full article

Galectins are a functionally diverse family of β-galactosyl-binding lectins that are ubiquitously present in animal species, with key roles in development and immune regulation. Recently, galectins have been found to recognize microbial glycosylated moieties, but the detailed mechanisms of their innate immune functions in mucosal epithelia have remained elusive. The zebrafish (Danio rerio) represents an ideal genetically tractable model to address these questions, as the skin, gills, and gut display mucosal surfaces exposed to the environment. In this study, we investigated the range of endogenous and microbial glycans that are recognized by zebrafish galectin Drgal1 present in epidermal mucus, which would be consistent with defense functions against a bacterial challenge. Results revealed that zebrafish galectin isoform Drgal1-L2 can recognize selected bacterial glycans, as well as zebrafish mucus glycans and cell-surface receptors for bacterial adhesins such as fibronectin (K_D = 1.593 × 10⁻⁶ M) and CD147 (K_D = 1.115 × 10⁻⁶ M). Furthermore, preliminary experiments revealed that Drgal1-L2 may hinder bacterial adhesion to epidermal mucus in about 50% at 2.5 μg/mL. Our results suggest that Drgal1-L2 present in epidermal mucus can prevent access of pathogenic bacteria to the epithelial cell surface by alternate or synergic binding to bacterial glycans and to zebrafish mucus components and epithelial receptors for bacterial adhesins. Thus, the present study provides key information for the testing of the abovementioned hypothesis by implementing gene-silencing approaches targeting both zebrafish Drgal1-L2 and its ligands. Full article

Streptococcus agalactiae, also known as Group B Streptococcus (GBS), is a major pathogen responsible for mastitis in dairy cows. It causes persistent and difficult-to-treat mammary infections, leading to reduced milk production. Baicalein, a flavonoid compound, exhibits anticancer, anti-inflammatory, and antibacterial activities; however, its specific mechanism of action against GBS remains unclear. This study aimed to investigate the mechanism by which baicalein inhibits GBS invasion of bovine mammary epithelial cells (bMECs). The results showed that baicalein at concentrations of 4 μg/mL or higher effectively inhibited 50% of the invasion of bMECs by GBS strain HB31 and exerted a concentration-dependent inhibitory effect on bacterial adhesion. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of baicalein against HB31 were both greater than 1024 μg/mL. Therefore, the antibacterial effect of baicalein alone may not fully account for its mechanism; other pathways likely contribute to the reduced invasiveness of GBS. To elucidate the mechanism by which baicalein inhibits GBS invasiveness, this study investigated both bacterial metabolism and gene expression. Metabolomic analysis revealed that baicalein treatment led to the downregulation of amino acid metabolites, including alanine and aspartic acid, as well as nucleotide metabolites such as adenine and UMP in GBS HB31. Additionally, the NADH/NAD⁺ ratio increased while ATP levels decreased, indicating that the overall metabolic activity of GBS was suppressed. Transcriptomic analysis focused on changes in invasion-associated virulence genes. The results showed that the expression of pbsP, an invasion-associated virulence gene, was significantly reduced, while the expression of hylB and cfb showed downward trends that did not reach statistical significance. In contrast, the expression of cylE and the two-component system vicKR was upregulated. The upregulation of cylE may be related to baicalein-induced oxidative stress in HB31. Furthermore, HB31 suppressed Nrf2-HO-1 mRNA expression, whereas baicalein activated the Nrf2 signaling pathway and reduced HB31-induced IL-6 and NF-κBmRNA expression. These findings provide new insights for the development of anti-virulence therapeutic strategies targeting GBS. Full article

Chronic wounds resulting from bacterial infection remain one of the main challenges in clinical practice. There is a pressing need to develop an injectable hydrogel sealant with multifunctional properties, including remodeling capabilities, self-healing, painless removal, and antibacterial activity, to promote tissue remodeling. In this work, aldehyde carboxymethylated agarose (ACMA) is employed for the first time as a bio-template. Dopamine (DA) is introduced onto the ACMA template via a reversible Schiff-base reaction, endowing it with biomineralization properties to synthesize DA-modified ACMA-Ag nanoparticles (ACMA-DA-Ag). Further, the prepared ACMA-DA-Ag, which possesses both antibacterial activity and injectable behavior, is incorporated into a guar gum hydrogel through the formation of borate/diol bonds, thereby forming a multiple-dynamic-bond crosslinked network. This hydrogel demonstrates adequate mechanical strength, injectability, remodeling capabilities, and self-healing performance. It can reassemble into a new hydrogel within 4 ± 0.6 min upon simple physical contact, and supports tissue adhesion. Furthermore, the hydrogel effectively covers irregular-shaped wound and can be removed without causing secondary injury. More importantly, this multifunctional hydrogel is cost-effective, easy to synthesize, and simple to use, significantly accelerating skin regeneration and promoting the formation of skin appendages, such as hair follicles. The outcome of this research not only serves a tissue sealant for wound healing, but also presents a new strategy for creating novel polysaccharide-based biomaterials. Full article

The growing need for sustainable strategies to reduce agro-industrial waste has stimulated interest in valorizing winery by-products as sources of high-value bioactive compounds. Wine lees, rich in phenolic compounds with well-documented antimicrobial activity, remain largely underutilized in the development of functional materials. In most cases, incorporation of bioactive agents relies on physical adsorption, which often results in weak adhesion and limited durability. In this study, phenolic extracts derived from wine lees and grape seed extract were incorporated into bacterial cellulose (BC) to develop bioactive materials with antimicrobial and antioxidant functionality. Two strategies were investigated: (i) direct immersion of BC in phenolic extracts and (ii) incorporation of extracts in BC membranes pre-modified with carboxymethyl cellulose (CMC) to enhance phenolic affinity and retention. The resulting materials were characterized for total phenolic content, antioxidant activity, and antimicrobial performance against bacterial strains (Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus). CMC-pretreated membranes significantly enhanced phenolic incorporation and antimicrobial performance, achieving a 99.9% reduction in E. coli after 24 h, while S. Typhimurium and S. aureus counts were below the detection limit (LOD < 1.0 log₁₀ CFU/mL). These findings demonstrate the potential of wine lees as a sustainable source of bioactive compounds for the development of antimicrobial cellulose-based materials, supporting circular bioeconomy strategies and their potential application in food packaging. Full article

Streptococcus canis is an opportunistic pathogen that colonises the mucosal surfaces and skin of its host. Though predominantly a veterinary pathogen affecting cats and dogs, S. canis has also been identified as the causative agent in severe human disease. IdeC is a secreted cysteine protease of S. canis that has a high specificity for IgG, cleaving at the hinge region. We show here that the protein binds back to the surface of the bacteria. Additionally, the protein contains a conserved Arg-Gly-Asp (RGD) motif, the minimal peptide sequence required for integrin binding. Several bacterial proteins containing RGD motifs have been implicated in adhesion and invasion of host cells. This RGD motif along with the ability of IdeC to bind back to the bacterial surface after secretion is the basis for this study into a potential secondary function of IdeC in adhesion and/or invasion. We used protein-coated latex beads to investigate the interaction of IdeC with epithelial and endothelial cells and, further, the extent to which the RGD motif is involved in this interaction by utilising an RGD->RGE recombinant protein. We also report here that the deletion of IdeC in S. canis results in a significant reduction in invasion into epithelial cells. Full article

Titanium alloys are widely used in dental implants due to their excellent mechanical properties. However, their inertness and poor antibacterial activity cause interfacial loosening and failure, shortening service life. This study integrates surface microtexturing with coating technologies, employing modified light-curing composite resins to boost the bioactivity of medical titanium alloys via surface modification. The results reveal that surface microtexturing enlarges the coating-substrate contact area by 42.5% compared with rough surfaces, concurrently diminishing stress per unit area, and the coating on microtextured Ti-6Al-4V (TC4) surfaces achieves adhesion with a damaged area of only 0.5%, thereby notably enhancing adhesion between the coating and TC4 matrix. In comparison, with rough surfaces (surface roughness of 0.658 μm), smooth TC4 planes (surface roughness of 0.014 μm) show a significantly reduced bacterial colony count (from 130 ± 6 to 42 ± 3) with an antibacterial rate of 67.7%, as the water contact angle on TC4 surfaces increases with decreasing roughness (reaching 80.95° on the smoothest surface), making bacterial adhesion more challenging and reducing colonization. The composite resin coating based on a mixture of titanium-doped hydroxyapatite and titanium dioxide (Ti-HA/TiO₂) further improves the antibacterial rate to 74.6% through a photocatalytic synergistic effect and endows TC4 with excellent remineralization capacity—mineralization deposits appear on the coated surface after 3 days of immersion in artificial saliva, while no obvious deposits are found on uncoated rough and smooth surfaces even after 7 days—thereby enhancing its bioactivity effectively. This study on the modification of Ti-based implant surfaces will enrich the field by introducing new technologies and methodologies. These advancements provide a theoretical basis for improvement of the remineralization capacity and antibacterial properties of Ti-based dental implants, thereby promoting broader biomedical applications. Full article

Background/Objectives: Klebsiella pneumoniae (K. pneumoniae) is a leading cause of serious hospital-acquired and community-acquired infections, with limited treatment options, especially for immunocompromised and critically ill patients. No licensed vaccine is currently available. The FimA antigen, a key fimbrial subunit essential for bacterial adhesion and invasion, represents a promising vaccine target. However, little is known about the immunodominant antibody responses against invasive K. pneumoniae. This study aimed to evaluate the immunogenicity and protective efficacy of recombinant FimA protein, to fine-map its immunodominant linear B-cell epitopes, and to assess the individual and combined protective capacity of these epitopes against both standard and clinically isolated K. pneumoniae strains. Methods: A murine model of lethal K. pneumoniae challenge was used. Recombinant FimA protein was administered to evaluate immunogenicity and protective efficacy. Immunodominant linear B-cell epitopes were identified by overlapping peptide ELISA using immune antisera. The identified epitopes were synthesized and conjugated to keyhole limpet hemocyanin (KLH). Mice were immunized with individual epitope-KLH conjugates or a mixture of all four, then challenged with the standard strain ATCC700721 or with multiple clinical isolates of distinct multilocus sequence types (MLST). Epitope-specific antibody responses (total IgG and IgG subclasses) and survival rates were measured. Results: Immunization with full-length recombinant FimA conferred 90% protection against lethal challenge with the standard strain ATCC700721 and induced robust IgG1-dominant antibody responses. Four novel immunodominant linear B-cell epitopes were identified: FimA_97–114, FimA_103–120, FimA_109–126, and FimA_145–160. Structural mapping revealed that the first three epitopes reside within the α-helical region, while FimA_145–160 is located in the β-sheet domain. These epitopes are highly conserved, exhibiting 100% sequence identity across 36 diverse K. pneumoniae strains. Among individual epitope-KLH conjugates, FimA_109–126-KLH induced the highest epitope-specific antibody titers, followed by FimA_103–120-KLH. Immunization with a mixture of all four epitope-KLH conjugates elicited significant cross-protection against multiple clinical isolates, achieving survival rates of 60%, 50%, 50%, and 40% against strains 10CYZ, 13LGY, 19ZXQ, and 22CZY, respectively. Protective immunity was primarily associated with IgG1 subtype responses. Conclusions: This study provides the first fine-mapping and protective evaluation of immunodominant linear B-cell epitopes within K. pneumoniae FimA. The identification of highly conserved, functionally relevant B-cell epitopes and the demonstration of cross-protection conferred by a multi-epitope formulation underscore the potential of FimA-based epitope-driven vaccines. These findings offer a promising strategy for the development of broadly protective vaccines against K. pneumoniae infections. Full article

Photothermal therapy (PTT) has emerged as a promising medical strategy for controlled and targeted drug delivery, due to its ability to trigger rapid release while minimizing damage to surrounding environments. Among different near-infrared (NIR)-responsive nanomaterials, carbon materials are of particular interest due to their multifunctional properties, with graphene oxide (GO) being a powerful photothermal therapy agent that can accelerate stimuli-responsive drug release. Herein, novel stimuli-responsive hydrogels based on polyvinyl alcohol (PVA), gelatin (Gel) and GO, loaded with natural quercetin (Q) were developed and evaluated for their physico-chemical properties, antibacterial and antifungal activities, photothermal Q release, and cellular metabolic activity. Upon NIR laser irradiation, after 10 min, Q was released twice as fast compared to conventional drug release without stimulation. The rapid release of Q by applying light radiation highlights the suitability of these hydrogels for controlled drug delivery applications. The PVA:Gel:GO/Q-hydrogels exhibited strong antimicrobial and antifungal performance (≥90% microbial reduction at higher GO concentrations). Furthermore, a significant reduction in S. aureus adhesion and invasion indicates the sample’s potential to mitigate bacterial infections. The PVA:Gel:GO/Q formulations exhibited high biocompatibility in Human Dermal Fibroblasts (HDF), demonstrating that Q improves the safety of PVA:Gel:GO-loaded hydrogels. These results offer promising potential for PVA:Gel:GO/Q hydrogels as advanced materials for photothermal-triggered drug delivery and antimicrobial applications. Full article

Bacterial biofilms are structured microbial communities enclosed within a self-produced extracellular polymeric substance matrix composed of polysaccharides, proteins, extracellular DNA, and lipids. This matrix promotes adhesion, structural stability, and the development of heterogeneous microenvironments that restrict antimicrobial penetration and shield bacteria from host immune responses. As a result, biofilms are major contributors to chronic, recurrent, device-related, and difficult-to-treat infections, posing a major challenge for clinical management and antimicrobial stewardship. This review summarizes current understandings of biofilm biology, its clinical relevance, including the stages of biofilm development, the composition and protective roles of the matrix, and the physiological heterogeneity that arises during maturation. It also examines key mechanisms underlying biofilm tolerance and resistance, such as limited antibiotic diffusion, and sequestration, enzymatic inactivation, efflux pump upregulation, persister cell formation, and horizontal gene transfer. In addition, it highlights important clinical settings in which biofilms are implicated, including cystic fibrosis, chronic wounds, osteomyelitis, implant- or device-associated infections, and breast implant illness, in which persistent implant-associated biofilms and the resulting chronic inflammatory milieu have been hypothesized to contribute to local and systemic manifestations in a subset of patients. The review further discusses conventional and emerging approaches for biofilm detection alongwith real-time monitoring. Biofilm-associated infections remain difficult to eradicate because persistence is driven by multiple interconnected protective mechanisms. Effective management therefore requires integrated strategies that combine accurate detection with multifaceted therapies, including antibiotics alongside matrix-disrupting enzymes, quorum-sensing inhibitors, bacteriophages, metabolic reactivators, and nanotechnology-based delivery systems. Advances in multi-omics and system-level modeling will be essential for developing next-generation strategies to prevent, monitor, and treat biofilm-associated disease. Full article

Lactiplantibacillus plantarum LP28 (LP28), isolated from traditional Taiwanese dried tofu, has been demonstrated to have substantial probiotic potential because it increases the production of short-chain fatty acids (SCFAs) and strengthens anti-inflammatory responses. In this study, the safety of LP28 was assessed using both in vitro and in vivo approaches, including whole-genome sequence analysis, the Ames bacterial reverse mutation assay, a chromosomal aberration test, a rodent peripheral blood micronucleus test, a 28-day subacute oral toxicity assay, and an assessment of hemolytic activity. In vitro phenotypic evaluation revealed that LP28 exhibited no hemolytic activity and was susceptible to all the tested antibiotics except kanamycin. In vivo assessments revealed no significant alterations in reticulocyte counts or micronuclei incidence in ICR mice, and SD rats exhibited no subacute toxicity at an oral LP28 dosage of 2000 mg/kg body weight/day for 28 days. Moreover, a whole-genome sequence analysis of LP28 revealed the absence of antimicrobial resistance genes, harmful virulence factors, and genes associated with biogenic amine synthesis. Additionally, the presence of genes involved in stress responses (e.g., acid, bile salt, heat, osmotic, and oxidative stresses) and adhesion-related genes was confirmed. Furthermore, LP28 contains six genes (plnA, plnE, plnF, plnJ, plnK, and plnN) that encode bacteriocin precursor peptides, suggesting the potential for enhanced probiotic effects through the production of antimicrobial plantaricins. These findings highlight the potential of LP28 as a safe and effective probiotic for human consumption. Full article

The objective of this study is to evaluate the efficiency of surgical instruments’ manual cleaning versus automated cleaning in an ultrasonic cleaner for the removal of biofilms on surgical forceps contaminated with Staphylococcus epidermidis and Pseudomonas aeruginosa. Subsequently, the residual microbial load was quantified through microbiological culture, aiming to evaluate the effectiveness of biofilm removal under different reprocessing conditions. Cleaning is an essential step in the processing of surgical instruments to ensure the effective removal of dirt and microorganisms. Through adhesion, microorganisms can attach to surfaces and form biofilms, organized structures surrounded by an extracellular matrix consisting of various components, which favor metabolic exchanges, adaptation, resistance, and bacterial dispersion. These biofilms increase the pathogenic potential of microorganisms, contributing to the occurrence of Healthcare-Associated Infections, and to avoid these, it is essential that preventive measures aimed at microbial reduction are adopted. Automated cleaning proved more effective than manual cleaning, and the combined approach achieved the greatest microbial reduction, though persistent contamination was still observed. The ability of adhesion and biofilm formation on the surfaces of surgical instruments is regarded as a challenge for complete microbial removal. These findings enhance the need for more rigorous reprocessing protocols and complementary strategies to ensure greater safety in the use of reusable instruments in clinical practice. Full article