Search Results (565)

Klebsiella pneumoniae is the second-most common opportunistic pathogen in clinical practice and has developed resistance to potent antibacterial drugs such as carbapenems. Therefore, developing safe and effective strategies for the prevention and treatment of K. pneumoniae infections remains a critical challenge. In this study, a strain named Tie-10 isolated from Antarctic samples demonstrated potent antibacterial activity against K. pneumoniae, which was subsequently identified as Bacillus nakamurai. The fermentation medium and culture conditions were systematically optimized through single-factor experiments, orthogonal array testing, and response surface methodology. The optimal medium composition was determined to be beef extract, peptone, and KNO₃. The culture conditions included a time of 24 h, temperature of 37 °C, pH of 7.0, and bottling volume of 80 mL. Antagonistic experiments demonstrated that the crude extract of B. nakamurai Tie-10 exhibited significant inhibitory activity against K. pneumoniae. The alkaline protease (AKP) assay demonstrated that the crude extract effectively disrupted the cellular integrity of K. pneumoniae, a finding further corroborated by scanning electron microscopy (SEM) analysis. Furthermore, the crude extract significantly inhibited extracellular protease secretion in K. pneumoniae, downregulated the expression of virulence-associated genes, and effectively disrupted biofilm formation. The study presented innovative strategies for the management and containment of K. pneumoniae infections. Full article

Background: Helicobacter pylori (H. pylori) is a major pathogen associated with a variety of gastrointestinal disorders, including gastritis, peptic ulcers, and gastric cancer. As a natural bioactive product, propolis exhibits multifaceted and multi-mechanistic effects. Due to its immunomodulatory, anti-inflammatory, and antioxidant properties, propolis has emerged as a promising therapeutic alternative, offering an innovative approach to managing H. pylori infections and providing new insights into addressing antibiotic resistance. Methods: This comprehensive review, synthesizing data from PubMed, ScienceDirect, and SciFinder, examines the mechanisms by which propolis combats H. pylori. Results: Propolis has demonstrated significant antibacterial efficacy against H. pylori in both in vitro and in vivo models. Its multitargeted mechanisms of action include direct inhibition of bacterial growth, interference with the expression of virulence factors, suppression of virulence-associated enzymes and toxin activity, immunomodulation, and anti-inflammatory effects. These combined actions alleviate gastric mucosal inflammation and damage, reduce bacterial colonization, and promote mucosal healing through antioxidant and repair-promoting effects. Furthermore, propolis disrupts oral biofilms, restores the balance of the oral microbiome, and exerts bactericidal effects in the oral cavity. Synergistic interactions between propolis and conventional medications or other natural agents highlight its potential as an adjunctive therapy. Conclusions: Propolis demonstrates dual functionality by inhibiting the release of inflammatory mediators and suppressing H. pylori growth, highlighting its potential as an adjuvant therapeutic agent. However, clinical translation requires standardized quality control and higher-level clinical evidence. Future research should focus on validating its clinical efficacy and determining optimal dosing regimens, and exploring its role in reducing H. pylori recurrence. Full article

Biofilms constitute a significant challenge in the therapy of infectious diseases, offering remarkable resistance to both pharmacological treatments and immunological elimination. This resilience is orchestrated through the regulation of extracellular polymeric molecules, metabolic dormancy, and quorum sensing, enabling biofilms to persist in both clinical and industrial environments. The resulting resistance exacerbates chronic infections and contributes to mounting economic burdens. This review examines the molecular and structural complexities that drive biofilm persistence and critically outlines the limitations of conventional diagnostic and therapeutic approaches. We emphasize advanced technologies such as super-resolution microscopy, microfluidics, and AI-driven modeling that are reshaping our understanding of biofilm dynamics and heterogeneity. Further, we highlight recent progress in biofilm-targeted therapies, including CRISPR-Cas-modified bacteriophages, quorum-sensing antagonists, enzyme-functionalized nanocarriers, and intelligent drug-delivery systems responsive to biofilm-specific cues. We also explore the utility of in vivo and ex vivo models that replicate clinical biofilm complexity and promote translational applicability. Finally, we discuss emerging interventions grounded in synthetic biology, such as engineered probiotic gene circuits and self-regulating microbial consortia, which offer innovative alternatives to conventional antimicrobials. Collectively, these interdisciplinary strategies mark a paradigm shift from reactive antibiotic therapy to precision-guided biofilm management. By integrating cutting-edge technologies with systems biology principles, this review proposes a comprehensive framework for disrupting biofilm architecture and redefining infection treatment in the post-antibiotic era. Full article

Xylella fastidiosa (Xf) is a Gram-negative bacterium responsible for severe diseases in several commercially significant crops, including olive, grapevine, citrus and almond. Its management is particularly challenging due to its transmission via widespread vector insects, its ability to form biofilms, its high genetic diversity and, sometimes, latent symptoms. Current control strategies focus on integrated and preventive approaches, including the use of resistant varieties, agronomic practices, and vector control through chemical and biological methods. Direct control of the bacterium has always been a complex challenge that includes strategies to limit vector presence and activity in the field; however, several compounds have recently been evaluated that are able to inhibit biofilm formation and Xf growth. This review provides an up-to-date summary of studies investigating the efficacy of various treatments based on organic compounds, synthetic molecules and salt- or metal-based formulations. By evaluating the results of in vitro and in vivo experiments, the most promising solutions were identified that address the main challenges and limitations of chemical control strategies. These include N-acetylcysteine and zinc- and copper-based formulations, which are effective and potentially transferable to the field for crops such as citrus and olive trees. Antimicrobial peptides and nanoparticles, on the other hand, have demonstrated high efficacy in vitro, although further studies directly in the field are required. The evidence emerging from the analyzed studies offer insights to guide future research towards more effective and sustainable management approaches to mitigate the spread and impact of Xf. Full article

Recurrent urinary tract infections (UTIs) pose a significant clinical challenge in both human and veterinary medicine, due to antibiotic-resistant and biofilm-forming bacteria. We hypothesized that high glucose levels in diabetic animals enhance biofilm formation and reduce antibiotic efficacy, promoting infection persistence. This study analyzed Escherichia coli from a diabetic female Labrador Retriever with recurrent UTIs over 18 months, focusing on antimicrobial resistance, biofilm-forming capacity, and genomic characterization. Most isolates (9/11) were resistant to ampicillin and fluoroquinolones. Whole genome sequencing of six selected isolates revealed that they belonged to the multidrug-resistant ST1193 lineage, a globally emerging clone associated with persistent infections. Phylogenetic analysis revealed clonal continuity across six UTI episodes, with two distinct clones identified: one during a coinfection in the second episode and another in the last episode. High-glucose conditions significantly enhanced biofilm production and dramatically reduced antibiotic susceptibility, as evidenced by a marked increase in minimum biofilm inhibitory concentrations (MBICs), which were at least 256-fold higher than the corresponding minimum inhibitory concentration (MIC). Sulfamethoxazole–trimethoprim demonstrated the strongest antibiofilm activity, though this was attenuated in glucose-supplemented environments. This research highlights the clinical relevance of glucosuria in diabetic patients and emphasizes the need for therapeutic strategies targeting biofilm-mediated antibiotic tolerance to improve the management of recurrent UTIs. Full article

Bacterial diseases are a major constraint to aquaculture productivity, driving extensive antibiotic use and raising concerns over antimicrobial resistance, environmental contamination, and food safety. Curcumin, a polyphenolic compound from Curcuma longa, exhibits broad-spectrum antimicrobial and immunomodulatory activities but is limited by poor water solubility, instability, and low bioavailability. This review was conducted through a literature search of Scopus, PubMed, Web of Science, and Google Scholar using targeted keywords, including curcumin nanoparticles, antibacterial, aquatic pathogens, nanotechnology, synthesis, and disease control. Titles and abstracts were screened for relevance, followed by full-text evaluation of selected studies. Key findings were critically analyzed and incorporated into the review. Findings from the literature indicate that curcumin nanoparticles, synthesized via milling, anti-solvent precipitation, ionic gelation, emulsification, spray drying, and metal/polymer nanocomposite formation, exhibit enhanced antibacterial activity against aquatic pathogens, including Aeromonas hydrophila, Vibrio parahaemolyticus, Escherichia coli, and Staphylococcus aureus. Optimally engineered curcumin nanoparticles (<100 nm, being mostly spherical, highly negatively charged) can penetrate bacterial membranes, disrupt biofilms, lower minimum inhibitory concentrations, and improve in vivo fish survival. Practical applications include dietary supplementation to boost fish immunity and growth, water disinfection to reduce pathogen loads, immersion therapy for external infections, and antimicrobial coatings for aquaculture equipment and surfaces, resulting in reduced infections and outbreaks, reduced mortality, improved water quality, and decreased antibiotic dependence. In conclusion, curcumin nanoparticles and curcumin-based nanocomposites present a versatile, eco-friendly approach to sustainable aquaculture disease management. However, further field-scale validation, safety assessment, and cost-effective production methods are necessary to enable commercial adoption. Full article

Background: Periprosthetic joint infections (PJIs) remain among the most challenging complications in orthopedic surgery, often requiring prolonged antibiotic therapy and complex surgical interventions. Oritavancin, a long-acting semisynthetic lipoglycopeptide approved for acute bacterial skin and skin structure infections, has emerged as a potential off-label agent in PJI treatment due to its favorable pharmacokinetic properties, potent Gram-positive coverage, and documented antibiofilm activity. Objectives: This comprehensive review aims to assess the current clinical and preclinical data regarding the potential use of oritavancin in the management of PJIs. Methods: A comprehensive literature search was conducted in three major databases. Results: Six studies were included. In vitro data demonstrated strong activity of oritavancin against methicillin-resistant Staphylococcus aureus and S. epidermidis biofilms, particularly in synergy with rifampin. Clinical reports described successful outcomes in both acute and chronic PJI cases, including those with limited surgical options. Weekly or monthly dosing regimens were well-tolerated and effective in suppressive and curative contexts. Adverse events were infrequent but included infusion-related reactions. Conclusions: Oritavancin represents a promising adjunct or alternative to conventional antimicrobial regimens in PJIs, particularly for outpatient management or in patients with multidrug-resistant Gram-positive infections. Further prospective studies are needed to define its role, optimal dosing, and long-term efficacy in this complex clinical setting. Full article

Pollution from synthetic polymers, particularly low-density polyethylene (LDPE), poses a significant environmental challenge due to its chemical stability and resistance to degradation. This study investigates an eco-biotechnological approach involving bacterial strains isolated from insect guts—Bacillus cereus LDPE-DB2 (from Achroia grisella) and Pseudomonas aeruginosa LDPE-DB26 (from Coptotermes formosanus)—which demonstrate the ability to degrade LDPE, potentially through the action of lignin-modifying enzymes. These strains exhibited notable biofilm formation, enzymatic activity, and mechanical destabilization of LDPE. LDPE-DB2 exhibited higher LDPE degradation efficiency than LDPE-DB26, achieving a greater weight loss of 19.8% compared with 11.6% after 45 days. LDPE-DB2 also formed denser biofilms (maximum protein content: 68.3 ± 2.3 µg/cm²) compared with LDPE-DB26 (55.2 ± 3.1 µg/cm²), indicating stronger surface adhesion. Additionally, LDPE-DB2 reduced LDPE tensile strength (TS) by 58.3% (from 15.3 MPa to 6.4 ± 0.4 MPa), whereas LDPE-DB26 induced a 43.1% reduction (to 8.7 ± 0.23 MPa). Molecular weight analysis revealed that LDPE-DB2 caused a 14.8% decrease in weight-averaged molecular weight (Mw) and a 59.1% reduction in number-averaged molecular weight (Mn), compared with 5.8% and 32.7%, respectively, for LDPE-DB26. Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and gel permeation chromatography (GPC) analyses revealed substantial polymer chain scission and crystallinity disruption. Gas chromatography–mass spectrometry (GC-MS) identified environmentally benign degradation products, including alkanes, alcohols, and carboxylic acids. This study demonstrates a sustainable route to polyethylene biotransformation using insect symbionts and provides insights for scalable, green plastic waste management strategies in line with circular economy goals. Full article

Aeromonas hydrophila is an important zoonotic bacterium that is related to multiple diseases in humans, terrestrial animals, and aquatic animals. Bacterial septicemia caused by A. hydrophila often results in high mortality and severe economic losses. Antibiotics, the major approach to dealing with bacterial infections, are limited due to the occurrence of antibiotic resistance. Anti-virulence strategies provide a promising approach to combat resistant bacterial infections. Here, growth curves, hemolysis, biofilm formation, and animal studies were performed to investigate the effect of fisetin against A. hydrophila. Moreover, RNA-seq technology was employed to determine the potent mechanism of fisetin. The results showed that fisetin could dose-dependently reduce the hemolytic activities mediated by aerolysin and hinder biofilm formation. Animal studies showed that treatment with 50 mg/kg fisetin could remarkably reduce the mortality to 40% in the infected group compared with fish in the fisetin-free group. Further, transcriptome analysis demonstrated that there were 565 differentially expressed genes (DEGs) after treatment with 16 μg/mL fisetin. Fisetin significantly impacted the pathways related to oxidative phosphorylation, the citrate cycle, and virulence factor regulation. Furthermore, 159 virulence-related genes were influenced after fisetin treatment. Collectively, these findings revealed that fisetin could mitigate the pathogenicity of A. hydrophila by affecting oxidative phosphorylation and the citrate cycle pathway as well as inhibiting the production of virulence factors. The study not only identified a powerful substance for managing A. hydrophila-associated diseases in aquaculture but also clarified the mechanism of plant medicines in controlling diseases caused by bacterial pathogens. Full article

Recent advances in microbiome research have highlighted the oral cavity as a complex and dynamic ecosystem, home to over 700 microbial species that play critical roles in both oral and systemic health. The oral microbiota not only maintains local tissue homeostasis but also serves as a reservoir for antimicrobial resistance (AMR) genes, contributing to the global spread of resistance. Frequent and sometimes inappropriate antibiotic use in dental practice, along with exposure to antiseptics and biocides, drives the emergence and horizontal transfer of resistance determinants within oral biofilms. This review synthesizes current knowledge on the molecular mechanisms and ecological drivers of AMR in the oral microbiome, emphasizing the clinical implications of dysbiosis and drug-resistant infections. The authors advocate for the development of dental clinical guidelines tailored to the unique characteristics of the oral microbiota, focusing on personalized therapy through molecular diagnostics, standardized AMR risk assessment, and the integration of non-antibiotic strategies such as probiotics and photodynamic therapy. Continuous education in antimicrobial stewardship and the implementation of oral-specific AMR surveillance is also highlighted as an essential component of effective resistance management. To support rational prescribing, a dedicated mobile application has been developed, leveraging microbiota data and resistance profiles to guide evidence-based, targeted therapy and reduce unnecessary antibiotic use. Collectively, these strategies aim to preserve antibiotic efficacy, ensure patient safety, and promote sustainable infection management in the dental field. Full article

Livestock-associated Staphylococcus species—particularly Staphylococcus aureus (S. aureus), Staphylococcus pseudintermedius (S. pseudintermedius), and coagulase-negative staphylococci (CoNS)—pose escalating threats to animal health, food safety, and public health due to their evolving antimicrobial resistance (AMR) profiles. This review synthesizes recent insights into the molecular epidemiology, resistance determinants, and host adaptation strategies of these pathogens across food-producing animals. We highlight the role of mobile genetic elements (MGEs), clonal dissemination, and biofilm formation in shaping multidrug resistance (MDR) patterns. Diagnostic advancements, including MALDI-TOF MS, whole-genome sequencing (WGS), and PCR-based assays, are discussed alongside treatment challenges arising from therapeutic failures and limited vaccine efficacy. The review critically examines current AMR surveillance gaps and the need for integrative One Health frameworks that encompass animals, humans, and the environment. Novel tools such as metagenomics, real-time genomic surveillance, and artificial intelligence (AI)-driven analytics are proposed to enhance predictive monitoring and resistance management. Together, these insights underscore the urgency of coordinated, evidence-based interventions to curb the spread of MDR staphylococci and safeguard One Health. Full article

Ensuring the safe reuse or discharge of treated wastewater is critical to achieving environmental sustainability, particularly in regions facing growing water stress. This study introduces a biological approach using Bacillus thuringiensis (Bt) biofilm formation as an indicator of treated wastewater quality from three wastewater treatment plants (WWTPs) in Deep East Texas. Treated wastewater samples were collected from chlorine and sulfur dioxide treatment stages at WWTPs in Nacogdoches, San Augustine, and San Jacinto counties. We assessed biofilm development through optical density and scanning electron microscopy (SEM) and evaluated changes in key anions (F⁻, Cl⁻, NO₂⁻, Br⁻, NO₃⁻, PO₄³⁻, and SO₄²⁻) using ion chromatography (IC). A two-tailed Student’s t-test was used to evaluate statistical significance (p ≤ 0.05). Remarkably, biofilm formation occurred in all samples, including those treated with chemical disinfectants, suggesting that microbial activity can still occur post-disinfection. Ion shifts, particularly the depletion of F⁻, NO₃⁻, and SO₄²⁻ and the release of Cl⁻, NO₂⁻, and PO₄³⁻, highlighted active microbial processes. These findings suggest that Bt biofilms can serve as sensitive, low-cost tools to monitor treated wastewater, offering critical insights into potential reuse risks and supporting more sustainable water management. Full article

Postharvest losses in fruits and vegetables, estimated at 20–50% globally, undermine food security and economic stability. Biological control agents (BCAs), including bacteria, yeasts, and fungi, are emerging as eco-friendly alternatives to synthetic fungicides. This review comprehensively analyzes advances in BCAs for postharvest disease control and highlights their mechanisms, impacts on produce quality, and integration into sustainable systems. Additionally, this review delves into the innovative role of nanotechnology-enhanced BCAs (Nano-BCAs), emphasizing nanoencapsulation, improved biofilm formation, targeted delivery, and antimicrobial synergy. While promising, Nano-BCA application requires risk assessment, regulatory clarity, and cost-effective scalability. This synthesis aims to guide future research and application toward sustainable, safe, and efficient postharvest disease management. Full article

Bovine mastitis, particularly that caused by Staphylococcus aureus, presents a major challenge to dairy production worldwide due to its economic impact, animal welfare concerns, and zoonotic potential. This narrative review synthesizes current literature on the epidemiology, pathogenesis, resistance patterns, and control strategies related to S. aureus-associated mastitis in dairy cattle. It highlights the pathogen’s virulence mechanisms, such as biofilm formation, immune evasion, and toxin production, that facilitate persistent infections. The review compiles global prevalence data, revealing significant geographic variation and disparities between clinical and subclinical cases. Antimicrobial resistance, especially the emergence of methicillin-resistant S. aureus (MRSA), is extensively examined alongside resistance gene profiles. Diagnostic approaches, including culture, PCR, MALDI-TOF MS, and AI-based systems, are evaluated for their sensitivity and field applicability. Additionally, the review addresses public health implications, zoonotic risks, and One Health perspectives, culminating in an exploration of prevention strategies, including improved hygiene, vaccination, dry cow therapy, and AI-driven herd management. The findings emphasize the urgent need for integrated surveillance, precision diagnostics, and targeted interventions to mitigate the burden of S. aureus mastitis. Full article

Pseudomonas aeruginosa poses significant health threats due to its multidrug-resistant profile, particularly affecting immunocompromised individuals. The pathogen’s ability to produce virulence factors and antibiotic-resistant biofilms, orchestrated through quorum-sensing (QS) mechanisms, complicates conventional therapeutic interventions. This review aims to critically assess the potential of anti-QS strategies as alternatives to antibiotics against P. aeruginosa infections. Comprehensive literature searches were conducted using databases such as PubMed, Scopus, and Web of Science, focusing on studies addressing QS inhibition strategies published recently. Anti-QS strategies significantly attenuate bacterial virulence by disrupting QS-regulated genes involved in biofilm formation, motility, toxin secretion, and immune evasion. These interventions reduce the selective pressure for resistance and enhance antibiotic efficacy when used in combination therapies. Despite promising outcomes, practical application faces challenges, including specificity of inhibitors, pharmacokinetic limitations, potential cytotoxicity, and bacterial adaptability leading to resistance. Future perspectives should focus on multi-target QS inhibitors, advanced delivery systems, rigorous preclinical validations, and clinical translation frameworks. Addressing current limitations through multidisciplinary research can lead to clinically viable QS-targeted therapies, offering sustainable alternatives to traditional antibiotics and effectively managing antibiotic resistance. Full article