Search Results (2,026)

Background/Objectives: Salmonella enterica (S. enterica) is a major poultry-associated foodborne pathogen and a persistent public health concern. The global rise in antimicrobial resistance has accelerated the search for alternative control strategies, including the use of bacteriophages. However, their successful application requires a comprehensive evaluation of their biological performance, genomic safety, and functional proteins. This study aimed to characterize Salmonella phage WP110 and assess its potential as a biocontrol agent in broiler-associated production systems. Methods: Phage WP110 was evaluated against 251 S. enterica isolates from broiler-related sources. Adsorption kinetics, one-step growth, environmental stability (temperature and pH), and effective multiplicity of infection (MOI) were determined using Salmonella Kentucky S1H28. Whole-genome sequencing (WGS) and bioinformatic analyses were performed for genome annotation, taxonomic classification, and safety evaluation. In addition, protein structural prediction of a putative endolysin (WP110-gp057) was conducted using AlphaFold2, followed by structural comparison and molecular docking with peptidoglycan. Biocontrol efficacy was evaluated in contaminated rice husk, chicken meat, and on non-food materials. Results: Phage WP110 demonstrated a broad lytic spectrum, lysing 248/251 S. enterica isolates (98.8%). It adsorbed rapidly (within 3–15 min) to host cells and exhibited a latent period of ~20 min with a burst size of 134 particles per infected cell. Phage WP110 remained stable at 4–45 °C and pH 5–11 but was inactivated at ≥75 °C and pH 2. Complete bacterial inactivation in broth assay was achieved at an MOI of 10⁴. Genomic analysis revealed a 110,216 bp linear dsDNA genome (39.74% GC) comprising 204 ORFs, 25 tRNAs, and long direct terminal repeats, with no detectable antibiotic resistance genes. Phylogenetic and intergenomic analyses classified phage WP110 as a novel species within the genus Epseptimavirus. Structural modeling of WP110-gp057 revealed conserved catalytic residues and high structural similarity to T5 endolysin, while docking analysis supported a structurally plausible interaction with peptidoglycan at the predicted active-site groove, consistent with its proposed role in host cell wall degradation. In application models, phage WP110 significantly reduced Salmonella contamination in rice husk (up to 4.3 log CFU/g), chicken meat (up to 1.7 log CFU/g), and on non-food material surfaces (0.7–1.5 log CFU reduction). Conclusions: Phage WP110 is a broad-host-range lytic phage with favorable infection kinetics, environmental robustness, and genomic safety. Its functionally supported endolysin and strong antibacterial efficacy across broiler-associated matrices highlight its potential as a biocontrol agent for Salmonella mitigation in poultry value chain. Full article

Antimicrobial resistance is a critical global challenge that necessitates the development of durable, material-based strategies to limit pathogen survival and transmission. Conventional cleaning and disinfection methods only provide transient protection due to rapid surface re-contamination. This study investigates the fabrication of polyethylene terephthalate (PET) surfaces designed for antibacterial applications via femtosecond laser-induced micro- and nanostructuring. Surface texturing was performed using a Ti:sapphire femtosecond laser (wavelength λ = 800 nm, pulse duration τ = 70 fs) at peak laser fluences (F) of 2.04 J/cm² and 4.08 J/cm², generating hierarchical surface textures with controlled morphology, spacing, and geometry through ultrafast, non-contact laser processing while preserving the bulk properties of PET. The resulting patterns, including parallel and intersecting microchannels decorated with laser-induced nanostructures, enabled tunable surface roughness and wettability, with water contact angles ranging from 33.21° to 118.2°. Comprehensive surface characterization, including morphological, topographical, and wettability analyses, was performed to establish structure–property relationships associated with previously reported antibacterial surface design principles. However, direct antibacterial performance was not evaluated in the present study and will be the subject of future investigations. In addition, the durability of the laser-structured PET was evaluated under simulated real-life conditions, including thermal cycling, ultraviolet exposure, abrasion, chemical resistance, and dust contamination. The structured surfaces demonstrated high structural and functional stability following environmental testing. The results indicate that the laser-induced surface modifications remain stable under conditions representative of prolonged practical use, supporting their potential long-term applicability for antibacterial and self-cleaning PET surfaces. Full article

The rapid emergence and dissemination of antimicrobial resistance (AMR) among bacterial pathogens, particularly the ESKAPE group (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.), represents one of the most pressing global public health challenges, contributing to increased morbidity, mortality, and healthcare costs. The limited development of new antibiotic classes over the past two decades has intensified the search for structurally novel antimicrobial agents and adjuvants capable of overcoming multidrug resistance. Natural products continue to serve as an invaluable source of anti-infective drug leads owing to their remarkable structural diversity and broad spectrum of biological activities. Mangrove ecosystems, located at the interface of terrestrial and marine environments, harbor highly diverse microbial communities, including fungi that have evolved under extreme environmental conditions and produce a wide range of unique secondary metabolites. Beyond their ecological significance, mangrove-associated fungi have emerged as prolific producers of bioactive compounds with promising antibacterial activity against multidrug-resistant pathogens. This review comprehensively summarizes recent advances (2018–2026) in the discovery of antibacterial metabolites from mangrove-associated fungi active against ESKAPE pathogens, which discusses their structural diversity, reported antimicrobial activities, and emerging strategies for accelerating natural product discovery, including genome mining, metabolomics, OSMAC, adaptive laboratory evolution, and artificial intelligence-assisted approaches. A total of 139 chemically distinct metabolites (Compounds 1–139) isolated from mangrove-associated fungi are critically reviewed, highlighting their potential as promising leads for the development of next-generation antimicrobial agents against ESKAPE pathogens. Full article

Multidrug-resistant hypervirulent Klebsiella pneumoniae caused by the improper use of antibiotics has become a major threat to the dairy industry and public health, posing a major challenge to the treatment of bovine mastitis. The resurgence of phage (and its lysozyme therapy) provides a novel strategy to combat such infections. In this study, bovine Klebsiella pneumoniae phage vB_Kpn_B01 nucleic acid was used as a template to successfully achieve the prokaryotic expression of its endolysin. The results of protein gene annotation and prediction showed that Lysin K had the function of lyase, and was designated Lysin K. After optimizing the production conditions, Lysin K could be produced in a soluble form after induction with 0.25 mmol/L IPTG at 37 °C for 16 h, and the concentration was 100 μg/mL after purification. The stability test confirmed that Lysin K can maintain stable antibacterial activity over a wide temperature and pH range. The minimum inhibitory concentration (MIC) of Lysin K was 0.01 μg/mL and remained stable in milk. The Lysin K showed strong lysis activity in vitro and could effectively lyse three types of multidrug-resistant hypervirulent Klebsiella pneumoniae. In the mouse mastitis model induced by Klebsiella pneumoniae KP18 (10⁸ CFU/mL), the intervention of Lysin K can significantly reduce the bacterial load, alleviate the inflammatory response, and restore the normal functional structure of the target mammary gland. In summary, Lysin K has valuable application prospect in the prevention and treatment of bovine mastitis caused by drug-resistant Klebsiella pneumoniae and the development of phage lysin preparations. Full article

The escalating crisis of bacterial antimicrobial resistance necessitates the discovery of novel antibacterial agents with distinct mechanisms of action. Ursolic acid (UA), a naturally abundant pentacyclic triterpenoid, serves as a promising scaffold for structural modification. In this study, a series of 26 novel UA derivatives (A1–A7 and B1–B19) were designed and synthesized by introducing various substituents at the C-28 carboxyl group via a chloroacetyl chloride linker. Their antibacterial activities were evaluated against S. aureus, S. epidermidis, E. coli, and P. aeruginosa using the microbroth dilution method. Among them, compound B1 exhibited the most potent activity, with a minimum inhibitory concentration (MIC) of 37.5 μg/mL against S. aureus and 75 μg/mL against E. coli. Antibacterial kinetic and time-kill curve assays confirmed the sustained bactericidal effect of B1. Furthermore, B1 significantly inhibited biofilm formation in both S. aureus and E. coli in a time-dependent manner. Molecular docking studies revealed that B1 binds spontaneously to the S. aureus SarA protein through three hydrogen bonds and π-π stacking interactions, providing a structural basis for its antibacterial and anti-biofilm activities. This study demonstrates that piperazine-modified UA derivative B1 is a promising antibacterial candidate and offers a new strategy for the structural optimization of ursolic acid. Full article

Acinetobacter baumannii is a microorganism of major global clinical importance, whose carbapenem-resistant phenotype is considered a priority target for the development of new antimicrobial agents. Carbapenem-resistant A. baumannii is associated with healthcare-associated infections and exhibits high mortality rates, prolonged hospital stays, and extensive use of intensive care units. As a control strategy, green-synthesized silver nanoparticles have gained increasing attention. Based on this, the aim of this study was to synthesize a novel triphasic silver nanocomposite, characterize it, and evaluate its antibacterial activity against extensively drug-resistant and pan-drug-resistant isolates. The nanocomposite was synthesized using cell-free bacterial supernatant and was physicochemically characterized regarding concentration, size, morphology, and crystallinity. Its antibacterial activity was assessed using broth microdilution and time–kill assays, followed by toxicity assays using human erythrocytes. A nanoscale and stable nanocomposite was obtained and was composed of metallic silver, silver chloride, and silver phosphate, which exhibited antibacterial activity against all tested isolates. In the toxicity assay, the nanocomposite demonstrated low toxicity and a high selectivity index. These findings demonstrate that Ag/AgCl/Ag₃PO₄ nanocomposite exhibits strong activity against resistant phenotypes for which therapeutic options are limited, highlighting its potential as a control strategy against this pathogen. Full article

The isoxazole-5-one ring system is a central structure in many synthetic bioactive molecules, showing a wide range of biological activities, including antibacterial, antitumor, anticorrosion, antifungal, antituberculosis, and antioxidant. They are also applied as agrochemicals with potential fungicidal effects. Given various applications, these pharmaceutically and biologically significant heterocyclic compounds have attracted the attention of chemistry researchers. This study aimed to investigate the application of glycerol as a reaction medium for the three-component synthesis of arylidenisoxazol-5(4H)-one derivatives. The results of the optimized investigations revealed that 3.0 mL of glycerol is the best reaction medium. Evaluation of the effect of reaction temperature showed that the best temperature for this strategy is 60 °C. In the present environmentally friendly study, the desired heterocyclic compounds were quickly synthesized via a one-pot three-component reaction of two keto-esters with hydroxylamine hydrochloride and a number of aryl/heteroaryl aldehydes. This synthetic approach has significant merits, such as cost-effectiveness of the reaction medium, rapid green synthesis, operational simplicity, easy workup, avoiding chromatographic purification, sustainability, acceptable yields, and relatively inexpensive as well as commercially available starting materials. Full article

Cryptococcus neoformans and Cryptococcus gatti are the two most common pathogenic species of the encapsulated yeast genus Cryptococcus and have been linked to fatal neurologic infections in both immunocompromised and healthy individuals. Cryptococcosis, which includes AIDS-defining diseases such as cryptococcal meningitis and meningoencephalitis, is the most frequent fungal infection of the central nervous system, with Africa having the greatest fatality rate. The goal of this study was to identify and characterize C. neoformans from pigeon and bat droppings, which are thought to be environmental reservoirs for the yeast and to determine their relatedness to clinical species. A total of 588 dried and 55 moist pigeon droppings, as well as 50 moist bat droppings, were collected from 18 sites in Ghana’s Greater Accra and Western regions, from sources which included markets, a church, households, and a public park. Seven clinical archived C. neoformans isolates were also retrieved from the Central Laboratory of the Korle-Bu Teaching Hospital (KBTH), Greater Accra. Using conventional methods and partial Multi-Locus Sequence Typing (MLST), 49 Cryptococcus neoformans var grubii were isolated from dried pigeon droppings only, yielding a prevalence of 7%. The sequence type (ST)/MLST group could not be defined based on the available data, although the allele types of the housekeeping genes in some of the isolates were identified. Some clinical strains had allele types that were found among the environmental strains, giving preliminary evidence of possible genetic relatedness, highlighting the need for more comprehensive genomic surveillance approaches, to better characterize environmental and clinical cryptococcal isolate transmission patterns and genetic relationships. This work also adds to the global literature supporting pigeon droppings as favorable ecological niches for Cryptococcus. This study was conducted within a One Health framework, recognizing the interconnected roles of environmental reservoirs, animal-associated sources, and human health in the epidemiology of Cryptococcus infections. Full article

The growing global crisis of antimicrobial resistance (AMR) urgently demands non-classical therapies capable of evading established resistance mechanisms. Bacterial ferroptosis-like death, an iron-dependent process driven by lipid peroxidation, offers a promising strategy to circumvent conventional drug resistance. However, the clinical translation of ferroptosis-like inducers is hindered by poor water solubility and off-target systemic toxicity. Featuring tunable physicochemical characteristics and proven clinical biosafety, liposomes stand out as a viable platform to resolve these translational bottlenecks. Although antibacterial nanomedicines have been extensively investigated, the specific synergies between liposomal engineering and bacterial ferroptosis-like pathways remain underexplored. To bridge this gap, this review systematically delineates the molecular cascades of bacterial ferroptosis-like death and highlights unique mechanistic advantages of liposomes. Importantly, liposome-mediated ferroptosis-like antibacterial therapy faces prominent translational challenges, including biosafety concerns, insufficient stability, and targeting limitations. This review further outlines advanced liposomal engineering strategies to tackle the above obstacles and discusses pressing questions that should be the focus of future ferroptosis-like research. By integrating multidisciplinary research outcomes, this review may provide insights and feasible design guidelines to advance the translational development of liposomal ferroptosis-like inducers against AMR infections. Full article

Prosthetic joint infections (PJIs) remain a major challenge in orthopedic surgery due to the increasing prevalence of antimicrobial-resistant pathogens and their ability to form biofilms on implant surfaces. Local delivery of non-traditional antimicrobials through implant-associated biomaterials represents a promising strategy for preventing bacterial colonization while minimizing systemic antibiotic exposure. This study evaluated the antimicrobial activity and cytocompatibility of two bacteriophages (Phage K and Phage F1) and two antimicrobial peptide dendrimers (AMPDs; TNS18 and G3KL) against clinical isolates of Staphylococcus aureus and Staphylococcus epidermidis recovered from PJIs. Antimicrobial efficacy was assessed using solid and liquid culture assays, while cytocompatibility was evaluated using human osteoblast progenitor cells. Biofilm formation was also investigated under various in vitro conditions. Phages K and F1 demonstrated strong antibacterial activity against S. aureus isolates, whereas TNS18 showed pronounced inhibitory effects against S. epidermidis. All agents exhibited appropriate osteoblast compatibility, except Phage F1, at the highest multiplicity of infection tested. Biofilm formation was observed under several culture conditions, although substantial variability in biofilm stability limited the quantitative assessment of antimicrobial activity. These findings demonstrate complementary antimicrobial activity profiles between bacteriophages and AMPDs and support their further investigation as candidates for implant-associated antimicrobial delivery systems and orthopedic implant coatings. Full article

Post-operative infections remain a challenge in implant surgery, leading to prolonged treatment, increased costs, and implant failure. Localized antibiotic-delivery coatings are a promising strategy to reduce infection risk while maintaining biocompatibility. Here, we evaluate cold atmospheric pressure plasma (CAP) spraying as a solvent-free method to deposit polyvinyl alcohol (PVA) layers containing amikacin on stainless steel and to identify plasma parameters that control release and antibacterial activity. A 3 × 3 factorial design varied nozzle distance (15, 20, 25 mm) and speed (10, 15, 20 cm/s). Surface morphology was assessed by optical microscopy, amikacin release quantified by HPLC-HRMS, and antibacterial activity tested against Staphylococcus aureus and Escherichia coli using Kirby–Bauer disc diffusion. Two-way ANOVA with Tukey post hoc tests and nonparametric validation were applied. Cold plasma spraying speed significantly affected drug release, whereas distance and the interaction term were not significant. Lower spraying speeds produced thicker, more porous coatings with greater cumulative release and larger inhibition zones. Drug release profiles were best described by Weibull and first-order models, showing an initial burst followed by sustained release. These findings indicate that CAP spraying enables solvent-free fabrication of antibiotic-loaded PVA coatings with tunable release, and optimizing spraying speed improves coating mass, drug delivery, and antibacterial performance. Full article

Infection associated with orthopedic implants remains a major challenge in the development of biomimetic materials for bone tissue engineering. Surface modification strategies are widely employed to transform bioinert metallic substrates into bioactive interfaces that promote tissue integration while preventing bacterial colonization. This study investigated the effect of incorporating silver nanoparticles (nAg) into hydroxyapatite–barium titanate (HA–BT) coatings on their structural, mechanical, piezoelectric, biological, and antibacterial properties. Raw materials were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM), whereas coatings were evaluated by XRD, scanning electron microscopy (SEM), tensile adhesion testing, electrochemical analysis, piezoresponse force microscopy (PFM), cell viability, and antibacterial assays. The coatings exhibited secondary phases, including β-tricalcium phosphate (β-TCP), tetracalcium phosphate (TTCP), and calcium oxide (CaO), generated during atmospheric plasma spraying (APS), while no silver oxide phases were detected after nAg incorporation. SEM observations revealed homogeneous phase distribution and strong coating–substrate adhesion. The addition of nAg did not significantly affect adhesive strength (44.58 ± 2.2 MPa for HA30BT and 43.28 ± 2.8 MPa for HA30BT–nAg). Protein adsorption studies indicated moderate albumin affinity (K_ads = 0.45) for nAg-containing coatings. Both coatings exhibited piezodynamic activity with d₃₃ values of approximately 13 pm/V. MTT assays confirmed non-cytotoxic behavior, with viability reductions below 2%. Osteocalcin expression demonstrated comparable osteogenic activity in coatings with and without nAg, regardless of low-intensity pulsed ultrasound stimulation. These findings highlight the potential of HA–BT–nAg coatings as multifunctional surfaces for bone regeneration and infection prevention. Full article

Antimicrobial resistance (AMR) among pathogens involved in intra-abdominal infections (IAIs) represents a critical and escalating clinical challenge. The interconnected nature of antimicrobial resistance, spanning human medicine, veterinary practice, agricultural use and environmental reservoirs, has required coordinated international responses based on the ‘One Health’ principle. This study presents an update on efforts underway worldwide to develop new antibiotics, novel combined antimicrobial agents, and alternatives to classic therapies for IAIs. New antibiotics or compounds with antibacterial activity are currently in various stages of clinical trials, including several fluoroquinolones, beta-lactamase inhibitors, and polymyxin analogues. To reduce the risk of bacterial resistance, various additions to antimicrobial treatments are being explored, such as nanoparticles (NPs), antimicrobial peptides (AMPs), bacteriophages, the CRISPR/Cas system, and probiotics. Each modality offers distinct mechanisms that circumvent established resistance pathways, including multi-target membrane disruption, sequence-specific gene editing, and microbiome restoration. Current preclinical and clinical evidence is synthesized, and key translational barriers, including delivery challenges, safety concerns, regulatory complexity, and the need for IAI-specific pharmacokinetic data are critically examined. In conclusion, the convergence of novel antibiotic agents and non-traditional antimicrobial strategies reviewed herein provides the foundation for a new paradigm in the management of drug-resistant IAIs. The transition from a monotherapy-centric approach to an integrated, multi-modal treatment framework, guided by rapid diagnostics and informed by antimicrobial stewardship, will be essential to preserve therapeutic efficacy against AMR threats of the coming decades. Full article

Implant-associated infections remain one of the leading causes of failure in orthopaedic and dental implants, necessitating the development of multifunctional surface coatings capable of simultaneously enhancing corrosion resistance, bioactivity, and antibacterial performance. The aim of this study was to investigate how picosecond laser surface treatment modifies the structural, physicochemical, mechanical, electrochemical, bioactive, and antibacterial properties of magnetron-sputtered TiO₂/CuO coatings on Ti6Al4V alloy. Structural characterisation revealed that laser treatment transformed the predominantly amorphous TiO₂ matrix into a more crystalline rutile-containing structure while preserving the CuO phase. The laser surface-treated (LST) surface exhibited increased surface hydroxylation, enhanced wettability, and a slightly higher release of Cu ions. In addition to modifying the surface chemistry, laser treatment improved the mechanical characteristics of the coating, contributing to its overall durability and suitability for biomedical implant environments. Electrochemical impedance spectroscopy demonstrated that both coatings significantly improved the corrosion resistance of Ti6Al4V in simulated body fluid, whereas the laser-treated coating showed superior long-term stability and passive layer evolution. Following immersion, both surfaces promoted the formation of Ca–P-rich hydroxyapatite deposits, indicating favourable bioactivity. Antibacterial testing against Staphylococcus aureus revealed reductions in bacterial viability of 67% and 74% for the AD and LST coatings, respectively. The enhanced antibacterial performance of the laser-treated surface was attributed to the combined effects of increased crystallinity, surface hydroxylation, hydrophilicity, and copper ion release. The novelty of this work lies in demonstrating that picosecond laser post-treatment can simultaneously tailor the crystallinity, surface chemistry, morphology, corrosion resistance, bioactivity, and antibacterial performance of magnetron-sputtered TiO₂/CuO coatings without compromising coating integrity, thereby providing a promising multifunctional surface modification strategy for biomedical implants. Full article

With the rapid expansion of intensive aquaculture, the frequent outbreak of diseases and the overuse of antibiotics have become increasingly critical issues. Therefore, developing green and efficient antibiotic alternatives is essential for the sustainable growth of the industry. As a novel probiotic, Bacillus velezensis has shown great potential in improving the disease resistance of aquatic animals, owing to its excellent spore-forming ability, broad-spectrum antibacterial activity, and immunoregulatory functions. This paper systematically reviews the main mechanisms by which B. velezensis enhances disease resistance in aquatic animals, including directly inhibiting pathogens through the secretion of various lipopeptides and polyketides such as surfactin, iturin, and fengycin; interfering with pathogen quorum sensing systems via quorum quenching enzymes, thereby suppressing virulence factor expression and biofilm formation; modulating intestinal microbiota structure to increase the abundance of beneficial bacteria while reducing pathogenic proliferation; and activating the non-specific immune system of the host to upregulate immune-related indicators such as acid phosphatase, superoxide dismutase, and key cytokines (such as IL-1β, TNF-α). In addition, this review summarizes the application effects of B. velezensis on improving aquaculture water quality and promoting host growth. Furthermore, the potential ecological impacts on natural microbial communities and strain-dependent biosafety risks are evaluated. Finally, current research limitations—such as strain-specific functional differences, insufficient in-depth analysis of mechanisms, and inconsistent application outcomes—are discussed. Future prospects for promoting the efficient and stable application of B. velezensis in aquaculture through strategies including gene editing, multi-omics integration, and precise formulation compounding are also proposed. Full article