Search Results (2,045)

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

Background/Objectives: The rapid emergence of multidrug-resistant bacterial infections demands innovative non-antibiotic therapeutic strategies. Dual-modal photoresponse therapy integrating photodynamic (PDT) and photothermal (PTT) effects offers a promising rapid antibacterial approach, yet designing single-material systems with synergistic enhancement remains challenging. This study aims to develop uniform Cu-based metal–organic framework micrometer cubes (Cu-BN) for efficient PDT/PTT synergy. Methods: Cu-BN cubes were synthesized via a one-step hydrothermal method using Cu(NO₃)₂ and 2-amino-p-benzoic acid. The material’s dual-mode responsiveness to visible light (420 nm) and near-infrared light (808 nm) was characterized through UV–Vis spectroscopy, photothermal profiling, and reactive oxygen species (ROS) generation assays. Antibacterial efficacy against multidrug-resistant Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was quantified via colony counting under dual-light irradiation. Results: Under synergistic 420 + 808 nm irradiation for 15 min, Cu-BN (200 μg/mL) achieved rapid eradication of multidrug-resistant E. coli (99.94%) and S. aureus (99.83%). The material reached 58.6 °C under dual-light exposure, significantly exceeding single-light performance. Photodynamic analysis confirmed a 78.7% singlet oxygen (¹O₂) conversion rate. This enhancement stems from PTT-induced membrane permeabilization accelerating ROS diffusion, while PDT-generated ROS sensitized bacteria to thermal damage. Conclusions: This integrated design enables spatiotemporal PDT/PTT synergy within a single Cu-BN system, establishing a new paradigm for rapid-acting, broad-spectrum non-antibiotic antimicrobials. The work provides critical insights for developing light-responsive biomaterials against drug-resistant infections. Full article

Aim: Antibiotic de-escalation (ADE) is essential, but appears to be underperformed although being possible, which we refer to as a ‘missed opportunity’. We aimed to analyze the ADE missed opportunities in Gram-negative bloodstream infections (BSIs) in a setting with a high antimicrobial resistance profile. Methods: A retrospective, two-centered cohort study was performed from 1 January 2018 to 30 June 2019, including adults with mono- or polymicrobial Gram-negative BSIs. All ADE episodes and 30-day mortality were noted. Results/Discussion: Out of 273 BSIs (43 ADE vs. 230 no-ADE episodes), 101 were considered a ‘missed’ opportunity of ADE (36.9%, 101/273). In multivariate analysis, ADE opportunities were missed 4.4 times more (OR = 4.4; 95% CI 1.24–15.9) in the presence of hematological malignancy and 6.2 times more (OR = 6.2; 95% CI 1.76–22.2) in ESBL. Contrary to this, ADE opportunities were missed 0.24 times less (OR = 0.24; 95% CI 0.09–0.61) among patients with E. coli BSIs, and 0.17 less (OR = 0.17; 95% CI 0.05–0.67) if ertapenem was used as an empirical agent. The ADE missed opportunity group had a higher mortality rate, which is statistically significant in univariate analysis, but not in multivariate analysis. Conclusion: The presence of ESBL and hematological malignancy were the significant barriers to appropriate ADE practice in our study. A good stewardship program must address physician hesitation in ADE practice. Full article

Background/Objectives: This study examines how seasonality, pollution, and sample type (water and sediment) influence the presence and distribution of antibiotic resistance genes (ARGs), with a focus on antibiotic resistance genes (ARGs) located on plasmids (the complete set of plasmid-derived sequences, including ARGs) in a tropical urban river. Methods: Samples were collected from three sites along a pollution gradient in the Virilla River, Costa Rica, during three seasonal campaigns (wet 2021, dry 2022, and wet 2022). ARGs in water and sediment were quantified by qPCR, and metagenomic sequencing was applied to analyze chromosomal and plasmid-associated resistance profiles in sediments. Tobit and linear regression models, along with multivariate ordination, were used to assess spatial and seasonal trends. Results: During the wet season of 2021, the abundance of antibiotic resistance genes (ARGs) such as sul-1, intI-1, and tetA in water samples decreased significantly, likely due to dilution, while intI-1 and tetQ increased in sediments, suggesting particle-bound accumulation. In the wet season 2022, intI-1 remained low in water, qnrS increased, and sediments showed significant increases in tetQ, tetA, and qnrS, along with decreases in sul-1 and sul-2. Metagenomic analysis revealed spatial differences in plasmid-associated ARGs, with the highest abundance at the most polluted site (Site 3). Bacterial taxa also showed spatial differences, with greater plasmidome diversity and a higher representation of potential pathogens in the most contaminated site. Conclusions: Seasonality and pollution gradients jointly shape ARG dynamics in this tropical river. Plasmid-mediated resistance responds rapidly to environmental change and is enriched at polluted sites, while sediments serve as long-term reservoirs. These findings support the use of plasmid-based monitoring for antimicrobial resistance surveillance in aquatic systems. Full article

Background/Objectives: Enterococci, particularly Enterococcus faecalis and Enterococcus faecium, are Gram-positive cocci that can cause severe infections in hospitalized patients. The rise of vancomycin-resistant enterococci (VRE) and vancomycin-variable enterococci (VVE) poses significant challenges in healthcare settings due to their resistance to multiple antibiotics. Methods: We conducted a point prevalence survey (PPS) to assess the prevalence of VRE and VVE colonization in hospitalized patients. Rectal swabs were collected from 160 patients and analyzed using molecular assays (MAs) and culture. Whole-genome sequencing (WGS) and core-genome multilocus sequence typing (cgMLST) were performed to identify the genetic diversity. Results: Of the 160 rectal swabs collected, 54 (33.7%) tested positive for the vanA and/or vanB genes. Culture-based methods identified 47 positive samples (29.3%); of these, 44 isolates were identified as E. faecium and 3 as E. faecalis. Based on the resistance profiles, 35 isolates (74.5%) were classified as VRE, while 12 (25.5%) were classified as VVE. WGS and cgMLST analyses identified seven clusters of E. faecium, with sequence type (ST) 80 being the most prevalent. Various resistance genes and virulence factors were identified, and this study also highlighted intra- and inter-ward transmission of VRE strains. Conclusions: Our findings underscore the potential for virulence and resistance of both the VRE and VVE strains, and they highlight the importance of effective infection control measures to prevent their spread. VVE in particular should be carefully monitored as they often escape detection. Integrating molecular data with clinical information will hopefully enhance our ability to predict and prevent future VRE infections. Full article

This study was undertaken to identify foodborne bacteria and fungi from different parts of eggs depending on their storage duration, organoleptic properties, total viable count, and antibiotic resistance profile. Thirty-two samples were randomly collected from commercial layer farms in Mymensingh. Following the protocol of sample preparation, outer-surface and inner-content samples were streaked onto various selective media. Isolation and identification were carried out by observing Gram staining and biochemical properties. Molecular detection was confirmed through a PCR assay using specific primers for Salmonella spp., E. coli, Staphylococcus spp., and fungus (Simplicillium spp. and Saccharomyces spp.). To determine the antibiotic resistance profile, the disk diffusion method was followed against nine antibiotic disks. The isolation rate of E. coli, Salmonella spp., and Staphylococcus spp. was 53.13%, 40.63%, and 40.63%, respectively, in the outer eggshell and 15.63%, 25%, and 15.63%, respectively, in the inner content of the eggs. Regarding the fungus content (yeast and mold), 100% was obtained in the outer eggshell, whereas there was an absence of fungus in the inner content. It was observed that all the isolates of E. coli, Salmonella spp., and Staphylococcus spp. were highly sensitive to either Ciprofloxacin or Levofloxacin and extremely resistant to Amoxicillin or Azithromycin drug disks or both. The data also shows that storage duration had a proportional relationship with TVC and an inversely proportional relationship with organoleptic properties. This study indicates that eggs harbor multidrug-resistant foodborne bacteria, which might constitute a public health hazard if these antibiotic-resistant bacteria are transferred to humans. Full article

Background/Objectives: Celiac disease (CD) is an autoimmune disorder characterized by small intestinal enteropathy triggered by gluten ingestion, often associated with gut dysbiosis. The most effective treatment is strict adherence to a gluten-free diet (GFD), which alleviates symptoms. This study uniquely integrates taxonomic, functional, and resistance profiling to evaluate the gut microbiota of women with CD on a GFD. Methods: To evaluate the long-term impact of a GFD, this study analyzed the gut microbiota of 10 women with CD on a GFD for over a year compared to 10 healthy controls with unrestricted diets. Taxonomic diversity (16S rRNA gene sequencing and the analysis of α and β-diversity), metabolic functionality (Biolog EcoPlates^®), and antibiotic resistance profiles (Cenoantibiogram) were assessed. Results: Metagenomic analysis revealed no significant differences in taxonomic diversity but highlighted variations in the abundance of specific bacterial genera. Women with CD showed increased proportions of Bacteroides, Streptococcus, and Clostridium, associated with inflammation, but also elevated levels of beneficial genera such as Roseburia, Oxalobacter, and Paraprevotella. Despite no significant differences in metabolic diversity, higher minimum inhibitory concentrations (MICs) in women in the healthy control group suggest that dietary substrates in unrestricted diets may promote the proliferation of fast-growing bacteria capable of rapidly developing and disseminating antibiotic resistance mechanisms. Conclusions: These findings indicate that prolonged adherence to a GFD in CD supports remission of gut dysbiosis, enhances microbiota functionality, and may reduce the risk of antibiotic resistance, emphasizing the importance of dietary management in CD. Full article

Carbapenem-resistant Klebsiella pneumoniae (CR-Kp) is eroding therapeutic options for urinary tract infections. We isolated a multidrug-resistant strain from the urine of a chronically bacteriuric patient and confirmed its identity by Vitek-2 and MALDI-TOF MS. Initial disk-diffusion profiling against 48 antibiotics revealed susceptibility to only 5 agents. One month later, repeat testing showed that tetracycline alone remained active, highlighting the strain’s rapidly evolving resistome. Given the scarcity of drug options, we performed an “aromatogram” with seven pure essential oils, propolis, and two commercial phytotherapeutic blends. Biomicin Forte^® produced a 30 mm bactericidal halo, while thyme, tea tree, laurel, and palmarosa oils yielded clear inhibition zones of 11–22 mm. These in vitro data demonstrate that carefully selected plant-derived products can target CR-Kp where conventional antibiotics fail. Integrating aromatogram results into One Health’s stewardship plans may therefore help preserve last-line antibiotics and provide adjunctive options for persistent urinary infections. Full article

Over the years, macromycete fungi have been used as a source of food, part of religious rites and rituals, and as a medicinal remedy. Species with strong health-promoting potential include Hericium erinaceus, Cordyceps militaris, Ganoderma lucidum, Pleurotus ostreatus, Flammulina velutipes, and Inonotus obliquus. These species contain many bioactive compounds, including β-glucans, endo- and exogenous amino acids, polyphenols, terpenoids, sterols, B vitamins, minerals, and lovastatin. The level of some biologically active substances is species-specific, e.g., hericenones and erinacines, which have neuroprotective properties, and supporting the production of nerve growth factor in the brain for Hericium erinaceus. Due to their high health-promoting potential, mushrooms and substances isolated from them have found applications in livestock nutrition, improving their welfare and productivity. This phenomenon may be of particular importance in the nutrition of laying hens and broiler chickens, where an increase in pathogen resistance to antibiotics has been observed in recent years. Gallus gallus domesticus is a key farm animal for meat and egg production, so the search for new compounds to support bird health is important for food safety. Studies conducted to date indicate that feed supplementation with mushrooms has a beneficial effect on, among other things, bird weight gain; bone mineralisation; and meat and egg quality, including the lipid profile and protein content and shell thickness, and promotes the development of beneficial microbiota, thereby increasing immunity. Full article

Nasal irrigation (NI) is an effective, safe, low-cost strategy for treating and preventing upper respiratory tract diseases. High-volume, low-pressure saline irrigations are the most efficient method for removing infectious agents, allergens, and inflammatory mediators. This article reviews clinical evidence supporting NI use in various conditions: nasal congestion in infants, recurrent respiratory infections, acute and chronic rhinosinusitis, allergic and gestational rhinitis, empty nose syndrome, and post-endoscopic sinus surgery care. NI improves symptoms, reduces recurrence, enhances the efficacy of topical drugs, and decreases the need for antibiotics and decongestants. During the COVID-19 pandemic, NI has also been explored as a complementary measure to reduce viral load. Due to the safe profile and mechanical cleansing action on inflammatory mucus, nasal irrigations represent a valuable adjunctive treatment across a wide range of sinonasal conditions. Full article

Background/Objetives: Antimicrobial Resistance (AMR) is a multifaceted issue that the World Health Organization (WHO) identifies as one of the primary threats to global health for humans, animals, and the environment. In Colombia, AMR has been extensively studied at the hospital level; however, there are limited environmental studies, particularly concerning leachates from landfills. The objective of this study was to identify and determine the genetic relationships, as well as the sensitivity profiles to antibiotics and heavy metals, of ten Pseudomonas mendocina isolates from a leachate pond. Methods: Identification was conducted using MALDI-TOF (Matrix-Assisted Laser Desorption/Ionization Time-of-Flight), while genotyping was performed via rep-PCR. Antibiotic susceptibility to β-lactams, aminoglycosides, and quinolones was assessed using the Kirby-Bauer method. Additionally, sensitivity profile to heavy metals was evaluated using the broth microdilution technique. Results: Rep-PCR analysis indicated that 60% (n = 6/10) of the isolates exhibited a clonal relationship. Sensitivity testing revealed that 30% (n = 3/10) of the isolates displayed reduced sensitivity to aminoglycosides and β-lactams. Finally, the broth microdilution showed that 90% (n = 9/10) of the isolates were tolerant to copper sulfate. Conclusions: These results provide evidence that landfill leachates may serve as a potential reservoir for bacteria harboring antimicrobial resistance determinants. Full article

Background/Objectives: Listeria monocytogenes is a foodborne pathogen of major public health concern due to its ability to invade host cells and cause severe illness. This study aimed to develop and validate a multi-tiered screening pipeline to identify Bacillus strains with probiotic potential against L. monocytogenes. Methods: A total of 26 Bacillus isolates were screened for antimicrobial activity, gastrointestinal resilience, and host cell adhesion. A fluorescence-based infection assay using mCherry-expressing HCT 116 cells was used to assess cytoprotection against L. monocytogenes NCTC 7973. Eight strains significantly improved host cell viability and were validated by quantification of intracellular CFU. Two top candidates were tested in a murine model of listeriosis. The genome of the lead strain was sequenced to evaluate safety and biosynthetic potential. Results: B. subtilis CECT 8266 completely inhibited intracellular replication of L. monocytogenes in HCT 116 cells, reducing bacterial recovery to undetectable levels. In vivo, it decreased splenic bacterial burden by approximately 6-fold. Genomic analysis revealed eight bacteriocin biosynthetic clusters and silent antibiotic resistance genes within predicted genomic islands, as determined by CARD and Alien Hunter analysis. The strain also demonstrated bile and acid tolerance, as well as strong adhesion to epithelial cells. Conclusions: The proposed pipeline enables efficient identification of probiotic Bacillus strains with intracellular protective activity. B. subtilis CECT 8266 is a promising candidate for translational applications in food safety or health due to its efficacy, resilience, and safety profile. Full article

Background: Esophageal achalasia is a rare motility disorder characterized by impaired lower esophageal sphincter (LES) relaxation and food stasis. Surgical interventions, including Heller myotomy with fundoplication or peroral endoscopic myotomy (POEM), effectively alleviate symptoms but induce significant anatomical and functional alterations. In various gastrointestinal surgeries, microbiota have been implicated in modulating clinical outcomes; however, their role in achalasia surgery remains unexplored. Methods: We performed a narrative literature search of various databases to identify studies exploring potential interactions between the gastroesophageal microbiota, achalasia pathophysiology, and surgical treatment, proposing clinical implications and future research avenues. Results: Chronic esophageal stasis in achalasia promotes local dysbiosis by facilitating aberrant bacterial colonization. Surgical restoration of esophageal motility and gastroesophageal transit induces substantial shifts in the microbial ecosystem. Analogous microbiota alterations following procedures such as fundoplication, gastrectomy, and bariatric surgery underscore the significant impact of mechanical modifications on microbial composition. Comprehensive microbiota profiling in patients with achalasia may enable the identification of dysbiotic phenotypes predisposed to complications, thereby providing personalized therapeutic interventions including probiotics, prebiotics, dietary modulation, or targeted antibiotic therapy. These insights hold promise for clinical benefits, including the mitigation of inflammation and infection, monitoring of surgical efficacy through microbial biomarkers, and optimization of postoperative nutritional strategies to reestablish microbial homeostasis, ultimately enhancing patient outcomes beyond conventional treatment paradigms. Conclusions: The gastroesophageal microbiota is a compelling mediator of surgical outcomes in achalasia. Future investigations integrating microbiological and inflammatory profiling are warranted to elucidate the functional role of the gastroesophageal microbiota and assess its potential as a biomarker and therapeutic target. Full article

This study assessed microbiological contamination in street-sold meat products, focusing on Enterobacterales and coagulase-negative staphylococci (CoNS) species and their antibiotic resistance. Chicken and mutton street foods like shawarma and brochettes were tested for bacterial load, species distribution. and resistance profiles. The results showed significant contamination, with Enterobacter cloacae (5.38 Log 10 CFU/g). Staphylococcus lentus and Staphylococcus xylosus were also common, reaching 6.23 Log 10 CFU/g in some samples. Contamination levels varied significantly by food type, with chicken shawarma showing the highest risk. Antimicrobial susceptibility testing revealed high multidrug resistance, particularly among E. cloacae and Staphylococcus species. Biofilm formation an indicator of resistance was observed mainly in staphylococci and enhanced under fed-batch culture. These findings highlight public health concerns tied to poor hygiene and undercooking in street food environments. The study emphasizes the need for improved hygiene practices, standardized cooking methods, and systematic food safety monitoring to reduce contamination and antibiotic resistance risks. Full article

Background and Objectives: Cancer patients are particularly susceptible to infections caused by multidrug-resistant Gram-negative bacteria (MDR GNB) due to chemotherapy- or radiation therapy-induced immunosuppression. Colistin is often prescribed as a last-resort agent for MDR GNB infection, but its clinical benefit in oncology patients remains unclear. This study aims to evaluate the mortality risk associated with colistin versus non-colistin regimens in cancer patient with MDR GNB infections, stratified by resistance profiles, infection sites, and concomitant medication use. Materials and Methods: A retrospective cohort study was conducted in adult cancer patients with MDR GNB infections that are resistant to at least three antibiotic classes and identified from at least two anatomical sites at a tertiary care hospital in Korea. Propensity score-matched in a 1:3 ratio either to the colistin group or non-colistin group and multivariate Cox hazard regression analyses were used to evaluate mortality in cancer patients with MDR GNB infections, primarily Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Results: A total of 85 patients (29 patients in the colistin and 56 patients in the non-colistin group) were included in the analysis. Overall, colistin use did not show a statistically significant mortality benefit compared to non-colistin regimens (hazard ratio (HR) 0.93, 95% CI 0.47–1.87). However, the subgroup analysis revealed that colistin had a potential association with significantly lower mortality in pneumonia patients with aminoglycoside-resistant infections (HR 0.04, 95% CI 0.002–0.69). Concomitant use of antipsychotics and benzodiazepines in selected resistance profiles also correlated with improved outcomes. In contrast, a potential association was found between concomitant macrolide use and increased mortality in patients with fluoroquinolone- or penicillin-resistant profiles. Conclusions: Colistin may offer survival benefits in selected high-risk cancer patients with MDR GNB pneumonia. Treatment outcomes are influenced by resistance profiles, infection sites, and concomitant medications, indicating the significant importance of individualized antimicrobial therapy and antimicrobial stewardship in oncology patients. Full article