Search Results (1,142)

The global rise in antimicrobial resistance poses a major threat to public health, with multidrug-resistant bacterial infections expected to surpass cancer in mortality by 2050. As traditional antibiotic pipelines stagnate, novel therapeutic alternatives are critically needed. Antimicrobial peptides (AMPs), particularly those derived from marine organisms, have emerged as promising antimicrobial candidates due to their broad-spectrum activity, structural diversity, and distinctive mechanisms of action. Unlike conventional antibiotics, AMPs can disrupt microbial membranes, inhibit biofilm formation, and even modulate immune responses, making them highly effective against resistant bacteria. This review highlights the potential of marine AMPs as next-generation therapeutics, emphasizing their efficacy against multidrug-resistant pathogens and biofilm-associated infections. Furthermore, marine AMPs show promise in combating persister cells and disrupting quorum sensing pathways, offering new strategies for tackling chronic infections. Despite their potential, challenges such as production scalability and limited clinical validation remain; nevertheless, the use of new technologies and bioinformatic tools is accelerating the discovery and optimization of these peptides, paving the way for bypassing these challenges. This review consolidates current findings on marine AMPs, advocating for their continued exploration as viable tools in the fight against antimicrobial resistance. Full article

Background: Trichosporon spp. are opportunistic fungi, capable of causing infection, especially in critically ill individuals who often use broad-spectrum antibiotics, invasive devices, and have comorbidities. Objectives The aim of this study was to analyze individuals’ clinical characteristics, evaluate tolerance to biocides, as well as biofilm formation and efflux pump activity in isolates of Trichosporon asahii. Methods: Clinical isolates of T. asahii collected between 2020 and 2023 from both hospitalized and non-hospitalized individuals, of both sexes, regardless of age, were tested for tolerance to sodium hypochlorite, hydrogen peroxide, benzalkonium chloride, and ethyl alcohol. Efflux pump activity was also assessed using ethidium bromide, and biofilm formation was measured with the Safranin test. Clinical parameters such as outcomes, source, and length of hospitalization were analyzed through electronic medical records. Results: A total of 37 clinical isolates of T. asahii were identified. Thirty-three (83.8%) isolates were from hospitalized individuals, with 81.82% collected in ICUs, an average hospital stay of 35 days, and a mortality rate of 51.6%. The tested strains displayed the largest mean inhibition zone for 2% sodium hypochlorite, indicating lower tolerance. A high level of efflux pump expression was detected among clinical isolates. Biofilm formation was detected in 25/67.5% of the isolates. Conclusions: These findings highlight the clinical relevance of T. asahii, particularly in critically ill individuals, and underscore the pathogen’s ability to tolerate biocides, express efflux pumps, and form biofilms, all of which may contribute to its persistence and pathogenicity in hospital environments. Enhanced surveillance and effective microbial control measures are essential to mitigate the risks associated with T. asahii infections. Full article

Biofilms are structured communities of microorganisms encased in a self-produced extracellular matrix, and they represent one of the most widespread forms of microbial life on Earth. Their presence poses serious challenges in both environmental and clinical settings. In natural and industrial systems, biofilms contribute to water contamination, pipeline corrosion, and biofouling. Clinically, biofilm-associated infections are responsible for approximately 80% of all microbial infections, including endocarditis, osteomyelitis, cystic fibrosis, and chronic sinusitis. A particularly critical concern is their colonization of medical devices, where biofilms can lead to chronic infections, implant failure, and increased mortality. Implantable devices, such as orthopedic implants, cardiac pacemakers, cochlear implants, urinary catheters, and hernia meshes, are highly susceptible to microbial attachment and biofilm development. These infections are often recalcitrant to conventional antibiotics and frequently necessitate surgical revision. In the United States, over 500,000 biofilm-related implant infections occur annually, with prosthetic joint infections alone projected to incur revision surgery costs exceeding USD 500 million per year—a figure expected to rise to USD 1.62 billion by 2030. To address these challenges, surface modification of medical devices has emerged as a promising strategy to prevent bacterial adhesion and biofilm formation. This review focuses on recent advances in chemical surface functionalization using non-antibiotic agents, such as enzymes, chelating agents, quorum sensing quenching factors, biosurfactants, oxidizing compounds and nanoparticles, designed to enhance antifouling and mature biofilm eradication properties. These approaches aim not only to prevent device-associated infections but also to reduce dependence on antibiotics and mitigate the development of antimicrobial resistance. Full article

Foodborne illness caused by bacterial pathogens is a global health concern and results in millions of infections annually. Therefore, food products typically undergo several processing stages, including sanitation steps, before being distributed in an attempt to remove pathogens. However, many sanitation methods have compounding effects on the color, texture, flavor, and nutritional quality of the product or do not effectively reduce the pathogens that food can be exposed to. Some bacterial pathogens particularly possess traits and tactics that make them even more difficult to mitigate such as biofilm formation. Non-thermal plasma sanitation techniques, including plasma-treated water (PTW), have proven to be promising methods that significantly reduce pathogenic bacteria that food is exposed to. Published work reveals that PTW can effectively mitigate both gram-positive and gram-negative bacterial biofilms. This study presents a novel analysis of the differences in antimicrobial effects of PTW treatment between biofilm-forming gram-positive bacteria, commonly associated with foodborne illness, that are sporulating (Bacillus cereus) and non-sporulating (Listeria monocytogenes). After treatment with PTW, the results suggest the following hypotheses: (1) that the non-sporulating species experiences less membrane damage but a greater reduction in metabolic activity, leading to a possible viable but non-culturable (VBNC) state, and (2) that the sporulating species undergoes spore formation, which may subsequently convert into vegetative cells over time. PTW treatment on gram-positive bacterial biofilms that persist in food processing environments proves to be effective in reducing the proliferating abilities of the bacteria. However, the variance in PTW’s effects on metabolic activity and cell vitality between sporulating and non-sporulating species suggest that other survival tactics might be induced. This analysis further informs the application of PTW in food processing as an effective sanitation method. Full article

Antimicrobial resistance (AMR) has emerged as one of the most pressing global health challenges of our time. Alarming projections of increasing mortality from resistant infections highlight the urgent need for innovative solutions. While many candidates have shown promise in preliminary studies, they often encounter challenges in terms of efficacy and safety during clinical translation. This review examines cutting-edge approaches to combat AMR, with a focus on engineered antimicrobial peptides, functionalized nanoparticles, and advanced genomic therapies, including Clustered Regularly Interspaced Short Palindromic Repeats-associated proteins (CRISPR-Cas systems) and phage therapy. Recent advancements in these fields are critically analyzed, with a focus on their mechanisms of action, therapeutic potential, and current limitations. Emphasis is given to strategies targeting biofilm disruption and quorum sensing interference, which address key mechanisms of resistance. By synthesizing current knowledge, this work provides researchers with a comprehensive framework for developing next-generation antimicrobials, highlighting the most promising approaches for overcoming AMR through rational drug design and targeted therapies. Ultimately, this review aims to bridge the gap between experimental innovation and clinical application, providing valuable insights for developing effective and resistance-proof antimicrobial agents. Full article

Healthcare-associated infection, mainly through medical device-associated infection, remains a critical issue in hospital care. Bacterial adhesion, proliferation, and biofilm formation on the device surface have been considered the foremost cause of medical device-associated infection. Different means have been explored to reduce microbial attachment and proliferation, including forming a bactericidal or microbial adhesion-resistant surface layer. Fear of limited bactericidal capability if the dead microbes remained adhered to the surface has withheld the widespread use of a bactericidal surface in medical devices if it was intended for long-term use. By contrast, constructing a microbial adhesion-resistant or antifouling surface, such as a surface with zwitterionic functionality, would be more feasible for devices intended to be used for the long term. Nevertheless, a sophisticated multi-step chemical reaction process would be needed. Instead, a simple immersion method that utilized a novel mussel-inspired catechol compound with zwitterionic sulfobetaine functionality, ZDS, was explored in this investigation for the surface modification of substrates with distinctively different surface characteristics, including titanium and polyvinyl chloride. Dopamine, NaIO₄ oxidants, and chemicals that could affect ionic interactions (NaCl and polyethyleneimine) were added to the ZDS-containing immersion solution to compare their effects on modifying titanium and PVC substrates. Furthermore, a layer-by-layer immersion method, in which the substrate was first immersed in the no-ZDS-added dopamine-containing solution, followed by the ZDS-containing solution, was also attempted on the PVC substrate. By properly selecting the immersion solution formulation and additional NaIO₄ oxidation modification, the antibacterial capability of ZDS-modified substrates can be optimized without causing cytotoxicity. The maximum antibacterial percentages against S. aureus were 84.2% and 81.7% for the modified titanium and PVC substrate, respectively, and both modified surfaces did not show any cytotoxicity. Full article

Listeria monocytogenes is a life-threatening bacterial foodborne pathogen that can persist in food-processing facilities for years. Although phages can control L. monocytogenes during food production, phage-resistant bacterial subpopulations can regrow in phage-treated environments. In this study, an L. monocytogenes hly defective strain, NJ05-Δhly, was produced, which considerably regulated the interactions between L. monocytogenes and phages. Specifically, we observed a 76.92-fold decrease in the efficiency of plating of the defective strain following infection with the Listeria phage vB-LmoM-NJ05. The lytic effect was notably diminished at multiplicities of infection of 1 and 10. Furthermore, the inactivation of LLO impaired biofilm formation, which was completely suppressed and eliminated following treatment with 10⁸ PFU/mL of phage. Additionally, phages protected cells from mitochondrial membrane damage and the accumulation of mitochondrial reactive oxygen species induced by L. monocytogenes invasion. Transcriptomic analysis confirmed these findings, revealing the significant downregulation of genes associated with phage sensitivity, pathogenicity, biofilm formation, and motility in L. monocytogenes. These results underscore the vital role of LLO in regulating the pathogenicity, phage susceptibility, and biofilm formation of L. monocytogenes. These observations highlight the important role of virulence factors in phage applications and provide insights into the potential use of phages for developing biosanitizers. Full article

Background/Objectives: There is an increasing incidence of fungal infections in conjunction with the rise in resistance to medical treatment. Antimicrobial resistance is frequently associated with virulence factors such as adherence and the capacity of biofilm formation, which facilitates the evasion of the host immune response and resistance to drug action. Novel therapeutic strategies have been developed to overcome antimicrobial resistance, including the use of different type of nanomaterials: metallic (Au, Ag, Fe₃O₄ and ZnO), organic (e.g., chitosan, liposomes and lactic acid) or carbon-based (e.g., quantum dots, nanotubes and graphene) materials. The objective of this study was to evaluate the action of nanoparticles of different synthesis and with different coatings on fungi of medical interest. Methods: Literature research was conducted using PubMed and Google Scholar databases, and the following terms were employed in articles published up to June 2025: ‘nanoparticles’ in combination with ‘fungal biofilm’, ‘Candida biofilm’, ‘Aspergillus biofilm’, ‘Cryptococcus biofilm’, ‘Fusarium biofilm’ and ‘dermatophytes biofilm’. Results: The utilization of nanoparticles was found to exert a substantial impact on the reduction in fungal biofilm, despite the presence of substantial variability in minimum inhibitory concentration (MIC) values attributable to variations in nanoparticle type and the presence of capping agents. It was observed that the MIC values were lower for metallic nanoparticles, particularly silver, and for those synthesized with polylactic acid compared to the others. Conclusions: Despite the limited availability of data concerning the stability and biocompatibility of nanoparticles employed in the treatment of fungal biofilms, it can be posited that these results constitute a significant initial step. Full article

Avian pathogenic Escherichia coli (APEC) is highly infective in poultry, causing significant economic losses to the poultry industry. As an extraintestinal pathogenic strain, adherence is a critical step in the infection. The functions of several adhesins, including type I, P, and Curli fimbriae, have been extensively studied. However, the roles of other adhesins, like Sfm, remain largely unexplored. Sfm is widely present in E. coli. Although the Sfm cluster is an ortholog of the fim gene cluster of Salmonella type I fimbriae, the biological function of Sfm in APEC has not yet been elucidated. To investigate whether Sfm in APEC CE129 plays a role in virulence, in this study, we constructed recombinant strains by expressing Sfm in the fimbriae-deficient strain SE5000. Additionally, a CE129 sfmA mutant strain was constructed. The resulting changes in adherence, biofilm formation, resistance to macrophage phagocytosis, and resistance to serum bactericidal ability were observed. The adherence ability of CE129ΔsfmA was reduced by 41%. HD-11 cells demonstrated a 30% increase in the phagocytosis of CE129ΔsfmA, and a 50% reduction in SE5000 (pBR322-sfm). The sfm deletion mutant showed a 23.9% reduction in the resistance to serum bactericidal ability, while SE5000 (pBR322-sfm) displayed a 32% increase. SE5000 (pBR322-sfm) exhibited a 34% increase in biofilm formation, and CE129ΔsfmA demonstrated a 21% decrease. Real-time PCR was employed to examine the impact of Sfm deletion on the transcription level of key virulence factors (fimA, fliC, papC, tsh, ompA, and iss). The results indicated that Sfm in CE129 is closely associated with bacterial adherence and survivability, contributing to biofilm formation and influencing the expression of key virulence factors. This study yields initial insight into the functional roles of Sfm in APEC and provides a foundation for the effective control of E. coli in the poultry industry. Full article

Background/Objectives: The formation of oral biofilms in periodontal pockets and around dental implants with induction of periodontitis or peri-implantitis is an increasing problem in dental health. The intelligent design of a biofilm makes the bacteria embedded in the biofilm matrix highly tolerant to antiseptic therapy, often resulting in tooth or implant loss. The question therefore arises as to which mouthwashes have eradication potential against oral biofilm. Methods: A human oral biofilm model was developed based on donated blood plasma combined with buffy coats, inoculated with oral pathogenic bacterial species found in periodontal disease (Actinomyces naeslundii, Fusobacterium nucleatum, Streptococcus mitis, and Porphyromonas gingivalis). Over a span of 7 days, we tested different mouth rinsing and antiseptic solutions (Chlorhexidine, Listerine^®, NaOCl, Octenisept^®, and Octenident^®) covering the matured biofilm with 24 h renewal. Phosphate-buffered saline (PBS) was used as a control. Bacterial growth patterns were detected via quantitative polymerase chain reaction (qPCR) after 2, 4, and 7 days of treatment. Results: While all groups showed initial bacterial reduction, the control group demonstrated strong regrowth from day 2 to 4. Listerine showed a near-significant trend toward bacterial suppression. Additionally, strain-specific efficacy was observed, with Octenisept^® being most effective against Streptococcus mitis, Octenident^® and NaOCl showing superior suppression of Actinomyces naeslundii, and Listerine^® outperforming other solutions in reducing Fusobacterium nucleatum. Donor-specific, individual variability further influenced treatment outcomes, with distinct trends in bacterial suppression and regrowth observed across donors. Conclusions: These findings underscore the complexity of biofilm-associated infections and highlight the importance of targeted therapeutic approaches for managing bacterial biofilms. In this experiment, the donor-specific outcomes of the antimicrobial effects of the solutions may indicate that genetic predisposition/tolerance to oral infections appears to play a critical role in the control of oral biofilms. Full article

The emergence of multidrug-resistant (MDR) bacteria and biofilm-associated infections has created a significant hurdle for conventional antibiotics, prompting the exploration of alternative strategies. Photodynamic therapy (PDT), a technique that utilizes photosensitizers activated by light to produce ROS, has emerged as a beacon of hope in the fight against MDR microorganisms. Among the natural photosensitizers, hypocrellins (A and B) have shown remarkable potential with their dual-mode photodynamic action, generating ROS via both Type I (electron transfer) and Type II (singlet oxygen) pathways. This unique action disrupts bacterial biofilms and inactivates MDR pathogens. The amphiphilic nature of hypocrellins further enhances their promise, enabling deep biofilm penetration and ensuring potent antibacterial effects even in hypoxic environments, surpassing the capabilities of synthetic photosensitizers. This study critically examines the antimicrobial properties of hypocrellin-based PDT, emphasizing its mechanisms, advantages over traditional antibiotics, and effectiveness against MDR pathogens. Comparative analysis with other photosensitizers, the role of nanotechnology-enhanced delivery systems, and future clinical applications are explored. Its combination with nanotechnology enhances therapeutic outcomes, providing a viable alternative to conventional antibiotics. Further clinical research is essential to optimize its application and integration into antimicrobial treatment protocols. Full article

Mink (Neogale vison) is a commercially farmed animal of global importance. However, disease outbreaks during farming not only cause significant economic losses but also substantially increase the risk of zoonotic infections. The identification and characterization of pathogenic bacteria remain a major bottleneck restricting the development of healthy and sustainable mink farming. In this study, an LB medium was used to isolate a pale-white, rod-shaped, Gram-negative bacterial strain, Qf-1, from minks with pneumonia. Based on morphological characteristics, biochemical properties, 16S rRNA gene sequencing, and average nucleotide identity (ANI) analysis, strain Qf-1 was identified as Huaxiibacter chinensis Qf-1. Under laboratory conditions, H. chinensis Qf-1 induced typical pneumonia symptoms in Kunming mice. Furthermore, whole-genome sequencing of H. chinensis Qf-1 revealed its genome to be 4.77 Mb and to contain a single chromosome and one plasmid. The main virulence genes of H. chinensis Qf-1 were primarily associated with flgB, flgC, flgG, aceA, hemL, tssC1, csgD, hofB, ppdD, hcpA, and vgrGA, functioning in motility, biofilm formation, colonization ability, and secretion systems. Our findings contribute to a better understanding of their pathogenic mechanisms, thereby laying a theoretical foundation for further investigation into the complex interactions between gut microbiota and the host. Full article

Multidrug-resistant (MDR) biofilm infections characterized by densely packed microbial communities encased in protective extracellular matrices pose a formidable challenge to conventional antimicrobial therapies and are a major contributor to chronic, recurrent and device-associated infections. These biofilms significantly reduce antibiotic penetration, facilitate the survival of dormant persister cells and promote horizontal gene transfer, all of which contribute to the emergence and persistence of MDR pathogens. Metal nanoparticles (MNPs) have emerged as promising alternatives due to their potent antibiofilm properties. However, conventional synthesis methods are associated with high costs, complexity, inefficiency and negative environmental impacts. To overcome these limitations there has been a global push toward the development of sustainable and eco-friendly synthesis approaches. Recent advancements have demonstrated the successful use of various plant extracts, microbial cultures, and biomolecules for the green synthesis of MNPs, which offers biocompatibility, scalability, and environmental safety. This review provides a comprehensive overview of recent trends and the latest progress in the green synthesis of MNPs including silver (Ag), gold (Au), platinum (Pt), and selenium (Se), and also explores the mechanistic pathways and characterization techniques. Furthermore, it highlights the antibiofilm applications of these MNPs emphasizing their roles in disrupting biofilms and restoring the efficacy of existing antimicrobial strategies. Full article

Microbial biofilms present a formidable challenge in ophthalmology. Their intrinsic resistance to antibiotics and evasion of host immune defenses significantly complicate treatments for ocular infections such as conjunctivitis, keratitis, blepharitis, and endophthalmitis. These infections are often caused by pathogens, including Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans, particularly in patients using contact lenses or intraocular implants—devices that serve as surfaces for biofilm formation. The global rise in antimicrobial resistance has intensified the search for alternative treatment modalities. In this regard, plant-derived antimicrobials have emerged as promising candidates demonstrating broad-spectrum antimicrobial and antibiofilm activity through different mechanisms from those of conventional antibiotics. These mechanisms include inhibiting quorum sensing, disrupting established biofilm matrices, and interfering with microbial adhesion and communication. However, the clinical translation of phytochemicals faces significant barriers, including variability in chemical composition due to environmental and genetic factors, difficulties in standardization and reproducibility, poor water solubility and ocular bioavailability, and a lack of robust clinical trials evaluating their efficacy and safety in ophthalmic settings. Furthermore, regulatory uncertainties and the absence of unified guidelines for approving plant-derived formulations further hinder their integration into evidence-based ophthalmic practice. This review synthesizes the current knowledge on the pathogenesis and treatment of biofilm-associated ocular infections, critically evaluating plant-based antimicrobials as emerging therapeutic agents. Notably, resveratrol, curcumin, abietic acid, and selected essential oils demonstrated notable antibiofilm activity against S. aureus, P. aeruginosa, and C. albicans. These findings support the potential of phytochemicals as adjunctive or alternative agents in managing biofilm-associated ocular infections. By highlighting both their therapeutic promise and translational limitations, this review contributes to the ongoing discourse on sustainable, innovative approaches to managing antibiotic-resistant ocular infections. Full article

Background/Objectives: Endophytic fungi are valuable sources of bioactive compounds with potential therapeutic applications. This study aimed to evaluate the antifungal activity of secondary metabolites produced by Fusarium sp. isolated from Dizygostemon riparius, with particular focus on the impact of culture medium supplementation with halogenated and metallic additives on metabolite production. Methods: The fungus was cultivated in standard Czapek medium and media supplemented with NH₄Br or MnCl₂. Methanolic extracts were obtained, fractionated, and chemically characterised via LC-ESI-HRMS. In vitro antifungal assays, including MIC and MFC determinations and biofilm inhibition tests, were performed against Candida albicans strains. In vivo toxicity and efficacy were assessed using Tenebrio molitor larvae. Results: Fifteen metabolites were annotated, including known antifungals such as fusaric acid and cyclosporin A. Fractions EMBr4 and EMC5 demonstrated fungicidal activity with MIC values close to fluconazole and significantly inhibited biofilm formation and maturation. In vivo, these fractions displayed low acute toxicity and improved survival in infected larvae, comparable to fluconazole treatment. Conclusions: The results indicate that culture medium modulation enhances the production of bioactive metabolites by Fusarium sp., leading to extracts with notable antifungal efficacy and safety. EMBr4 and EMC5 are promising candidates for further development as antifungal agents, particularly for targeting biofilm-associated Candida infections. These findings support the potential of endophytic fungi as sources of novel therapeutics and warrant further mechanistic and pharmacological investigations. Full article