Search Results (9,711)

Background/Objectives: Multidrug-resistant (MDR) Escherichia coli is a critical One Health challenge, with rising resistance in both humans and animals. The present study aimed to compare antimicrobial resistance (AMR) profiles of E. coli isolates from hospitalized patients and food-producing animals in Satu Mare, a county located in northwestern Romania. Methods: Between 2022–2023, 701 samples were collected, leading to 571 non-duplicate E. coli isolates (420 human, 151 animal). Human strains were recovered from 21 hospital departments and originated from feces, urine, blood, sputum, ear secretions, cerebrospinal fluid, purulent wound secretions, and puncture fluids. Animal isolates were obtained from ceca collected at local slaughterhouses serving farms in north-west Romania, including samples from turkeys, broilers, and pigs. Antimicrobial susceptibility testing was performed against eight antimicrobials (amikacin, ampicillin, cefotaxime, ceftazidime, cefepime, ciprofloxacin, gentamicin, sulfamethoxazole/trimethoprim) using standardized methods. Resistance classification followed international definitions of MDR. Statistical associations between host species and resistance were assessed with chi-square tests. Results: Resistance levels were consistently higher in E. coli strains isolated from animals compared with those from humans (p < 0.05). Among human isolates, resistance to ampicillin (41.9%), ciprofloxacin (41.4%), and sulfamethoxazole/trimethoprim (45.7%) approached, but did not exceed 50%. In contrast, E. coli strains recovered from animals showed markedly higher resistance, exceeding 50% for ampicillin (78.8%), ciprofloxacin (65.6%), and cefotaxime (55.0%). Amikacin retained full activity against all animal isolates, whereas 2.8% of human strains were resistant. Overall, multidrug resistance (MDR) was observed in 70.0% of E. coli isolates from humans and 79.7% from animals, with the highest resistance burden in pig-derived isolates. Conclusions: The study underscores the veterinary sector as a key contributor to the maintenance and spread of MDR E. coli. Even in clinically healthy animals, resistance levels exceeded those observed in human isolates. These findings emphasize the need for coordinated One Health monitoring and stricter antimicrobial use policies in livestock to reduce transmission risks across human and animal populations. Full article

The emergence and global dissemination of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli (ESBL-E. coli) represent a major public health concern. However, the characterization and capacity for horizontal gene transfer (HGT) of ESBL-E. coli in captive black bears remain substantially understudied. In the present study, 19 ESBL-E. coli strains were successfully identified (13.38%, 19/142). A total of 11 sequence types (STs) were identified from 19 ESBL-E. coli strains using MLST. This included eight known types (ST10, ST2690, ST208, ST695, ST4160, ST540, ST3865 and ST2792) and three new STs. Antimicrobial susceptibility testing demonstrated that all 19 ESBL-E. coli exhibited high resistance to KZ (100.00%), CRO (78.95%), and CTX (73.68%). Polymerase chain reaction (PCR) screening for 14 β-lactam antibiotic resistance genes (ARGs) and their variants revealed that bla_CTX-M was the most prevalent, followed by bla_SHV, bla_TEM, and bla_DHA. Furthermore, eight β-lactamase variants were detected, including five bla_CTX-M variants (bla_CTX-M-15, bla_CTX-M-3, bla_CTX-M-14, bla_CTX-M-55, and bla_CTX-M-27) and one variant each of bla_SHV-1, bla_TEM-1, and bla_DHA-14. Conjugation assays revealed that eight ESBL-E. coli strains were capable of conjugative transfer. Five plasmid types (IncFII, IncW, IncFrepB, IncY, and IncHI1) and three mobile genetic elements (MGEs) (IS26, ISEcp1, and trbC) were identified as co-transferred with bla_CTX-M. ESBL-E. coli poses a potential threat to captive black bears and may lead to further transmission. Consequently, the implementation of continuous surveillance and targeted interventions is imperative to prevent the transmission of ESBL-E. coli. Full article

Background/Objectives: Pediatric infectious-disease admissions are common but heterogeneous. We characterized clinical, microbiological, and therapeutic patterns and identified high-risk subgroups relevant to antimicrobial stewardship. Methods: In an observational cohort of 136 children stratified by age, we recorded symptoms, diagnoses, culture results, pathogens, antibiotic therapy, and outcomes. A composite risk score integrating age and clinical/microbiological parameters was assessed. Results: Outcomes were generally favorable: intensive care unit (ICU) transfer 8.8% (95% confidence interval [CI]: 4.6–15.1), mortality 0.7% (95% CI: 0.1–3.9), and median length of stay (LOS) 10 days (interquartile range [IQR] 8–12). Pneumonia was the leading diagnosis (44.9%; 95% CI: 36.3–53.6). Among isolates, Escherichia coli (47.1%) and Klebsiella species (spp.) (27.9%) predominated. Pneumonia correlated with prolonged LOS (p = 0.006), and gastroenteritis with ICU transfer (p = 0.038) and longer LOS (p = 0.018). Mixed E. coli + Klebsiella infections were linked to prolonged stay (p = 0.021). The composite score identified a high-risk stratum with higher ICU transfer (p = 0.004) and prolonged stay (p = 0.006). Conclusions: Although overall outcomes were favorable, risk was not uniform. An age-stratified, multifactorial assessment—integrating clinical presentation, microbiology, and a composite score—identified pediatric subgroups with worse prognoses, supporting targeted monitoring and stewardship-aligned, age-aware empiric therapy. External validation is warranted. Full article

Background: The escalating burden of antimicrobial resistance (AMR) poses a critical threat to public health in Pakistan, with rates of high antibiotic consumption and limited standardized surveillance on AMR rates. Our study aimed to carry out a multicentric surveillance of AMR to generate regional antibiograms for Northern Punjab, Pakistan, to guide empirical antimicrobial therapy and stewardship efforts. Methods: A laboratory-based, retrospective cross-sectional study was conducted over a six-month period across three tertiary care hospitals. Socio-demographic, clinical, and microbiological data (including specimen type and antibiotic prescription rates) were collected from N = 485 patients with confirmed bacterial infections. Antimicrobial susceptibility testing was performed based on Clinical Laboratory Standards Institute (CLSI) recommendations. Statistical analyses were carried out using SPSS v.22.0. Results: In our study setting, Gram-positive bacteria were common causes (60.0%) of infections, with Staphylococcus aureus (12.2%) and Streptococcus pneumoniae (10.3%) being the most relevant. Among Gram-negative bacteria (40.0%), Escherichia coli (14.0%) and Pseudomonas aeruginosa (5.8%) were shown to be important pathogens. Overall, 25.0% of S. aureus isolates were methicillin-resistant (MRSA), while ~30% of E. coli showed resistance to third-generation cephalosporins (3GCs). Enterobacterales species had highly variable susceptibility rates (40–70%) for fluoroquinolones. Meropenem and vancomycin/linezolid retained high efficacy (>90%) against most Gram-negative and Gram-positive isolates, respectively. In all healthcare settings studied, ceftriaxone was the most frequently prescribed antibiotic. Conclusions: High levels of resistance against first-line antibiotics were noted in our setting of Northern Punjab, Pakistan, underscoring the critical need for robust antimicrobial stewardship programs, tailored to local institutional contexts, capabilities, and needs. The regional antibiogram developed based on our data may provide vital evidence for informing local empirical treatment guidelines, which need to be continuously updated. Full article

The non-medicinal parts of Polygonatum sibiricum (P. sibiricum) and Gentiana scabra (G. scabra) are abundant but underutilized in Liaoning Province, China, creating an environmental burden. Solid-state fermentation (SSF) offers a strategy to enhance their bioactivity, yet triple microbial co-fermentation remains underexplored. This study applied a triple microbiota—featuring Aspergillus niger (A. niger), Bacillus subtilis (B. subtilis), and Saccharomyces cerevisiae (S. cerevisiae)—to ferment the stems and leaves of both plants. Antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was assessed via the Kirby–Bauer test, while Liquid Chromatography–Tandem Mass Spectrometry (LC–MS/MS)-based non-targeted metabolomics identified differential metabolites and enriched pathways. Co-fermentation significantly increased the inhibition zones to 17.4 ± 0.8 mm for E. coli and 17.7 ± 0.3 mm for S. aureus, a 1.8-fold improvement over the unfermented controls (p < 0.001). Among the 2976 metabolites detected, 1236 were differentially expressed, with Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis highlighting activation of aminoacyl-tRNA biosynthesis, ABC transporter, and phenylalanine–tyrosine–tryptophan pathways. Differential abundance analysis indicated that the aminoacyl-tRNA pathway (DA score > 0.9) is critical for antimicrobial peptide synthesis. Phenylalanine derivatives, including 4-hydroxybenzaldehyde, which increased over 430-fold (Log₂ FC = 8.78), contributed to membrane-disruptive antibacterial effects. Mechanistically, A. niger hydrolyzes cellulose to release precursors, B. subtilis synthesizes antimicrobial peptides, and S. cerevisiae enhances metabolite solubility and excretion, collectively boosting antibacterial activity by 80%, suggesting a potent synergistic interaction among the triple microbiota. This cascade mechanism provides a scalable approach for valorizing approximately 55 million tons of traditional Chinese medicine (TCM) waste annually. Full article

Background/Objectives: Due to the numerical dominance of environmental and commensal strains, understanding antimicrobial resistance (AMR) transmission in Escherichia coli requires consideration of non-clinical as well as pathogenic isolates. In this cross-sectional study, associations between the genetic context of non-clinical E. coli and AMR carriage are examined in isolates sampled from different niches within a One Health continuum. Methods: Two hundred eighty-eight E. coli isolates collected in Alberta, Canada (2018–2019) from wastewater, well water, feces of broiler chickens and feedlot cattle, and retail beef and chicken meat were selected from existing surveillance collections using a stratified random sampling structure. Using short-read whole genome assemblies, phylogenetic relationships were inferred from pan-genome multiple sequence alignments. Principal coordinate analysis and permutational analysis of variance (PERMANOVA) of a Jaccard dissimilarity matrix derived from gene presence/absence data were used to investigate contributions of source and AMR strata to observe genetic dissimilarity. Population clustering and gene under- or over-representation by source and cluster were also explored. Results: Minimal phylogenetic segregation of isolates was noted based on source or AMR strata, and both contributed significant but small proportions of observed genetic dissimilarity, with the largest proportion attributed to phylogroup. There was notable diversity of E. coli within and between sources; however, in some larger clusters, differential gene presence/absence was potentially linked to ecological niche rather than source of isolation. Conclusions: This study highlights the ecological complexity of AMR in E. coli in non-clinical contexts, offering a novel lens on how niche-specific factors can influence population structure and AMR carriage. It also provides insight into apparent discrepancies in the literature regarding clustering of E. coli by source. These findings support a more integrative One Health approach to AMR surveillance, emphasizing the need to account for microbial diversity and niche-specific adaptation across interconnected systems. Full article

Urinary tract infections (UTIs) are a global health concern, with over 150 million cases annually, primarily caused by Escherichia coli. Due to anatomical differences, females, especially children and postmenopausal women, are four times more susceptible. Crucially, E. coli has developed widespread antimicrobial resistance (AMR), including resistance to broad-spectrum agents and the emergence of Extended-Spectrum Beta-Lactamase (ESBL)-producing strains. This retrospective study analyzed hospital records from 95 female patients with positive urine cultures at Siblin Governmental Hospital in 2024. Patients were stratified into three age categories: children (≤18 years), adults (18–64 years) and elderly patients (>64 years). Statistical analysis using SPSS focused on descriptive resistance patterns and differences across age groups. Overall, cephalothin (85.7%) and cefaclor (78.49%) exhibited the highest resistance rates. Conversely, tigecycline (97.22%) and ertapenem (91.67%) showed the highest susceptibility. Resistance patterns varied significantly by age. For instance, elderly patients showed high resistance to agents like Augmentin (52.5%) and cefixime (66.1%), while the pediatric group (≤18 years) displayed exceptionally high resistance to cefixime (90.0%). E. coli isolates show high resistance to conventionally used antibiotics, complicating UTI treatment. These findings highlight the need for continuous local surveillance, particularly focusing on third-generation cephalosporins and beta-lactamase production. Ultimately, age is a critical factor that must be considered when determining empirical antibiotic therapy for UTIs. Full article

Mastitis caused by Escherichia coli and Streptococcus uberis remains one of the leading causes of antimicrobial use in dairy cattle, contributing to resistance development and economic losses. This study evaluated the therapeutic potential of the natural flavonoid morin in clinical mastitis in dairy cows. The in vitro antimicrobial activity of morin (1–3% w/v) was assessed by disk diffusion, and the 3% formulation was selected for an in vivo field trial. Seventy-two Holstein–Friesian cows with mastitis caused by E. coli or S. uberis were randomly assigned to one of three intramammary treatments: 3% morin, phosphate-buffered saline, or an antibiotic, serving as a positive control. Somatic cell count (SCC) and clinical scores were monitored for seven days. In E. coli infections, morin significantly reduced somatic cell scores at 144 h and 168 h and improved clinical scores from 48 h onward, showing efficacy comparable to antibiotics. In S. uberis mastitis, morin induced clinical improvement at 96–168 h but resulted in slower and smaller SCC reduction than antibiotic control therapy. Phosphate-buffered saline produced no significant changes. These results indicate that morin exerts anti-inflammatory and supportive effects in bovine mastitis, particularly in Gram-negative infections, but is less effective against S. uberis. Further studies on pharmacokinetics, bacteriological cure rates, and optimized formulations are warranted to confirm its clinical utility. Full article

The growing need for effective antimicrobial polymeric materials has prompted extensive development of functional chitosan derivatives with enhanced physicochemical and biological properties. In this work, the conjugates of chitosan with 4-anisaldehyde (ChT-AA) were synthesised through Schiff base formation at various molar ratios and characterised using FT-IR, ¹H NMR, and thermal analysis techniques (TGA/DSC). The spectral data confirmed the successful formation of imine (C=N) linkages and the incorporation of aromatic anisaldehyde fragments into the chitosan structure. Thermal analysis demonstrated increased stability and a higher glass transition temperature for ChT-AA compared with native chitosan, indicating reduced polymer chain mobility and enhanced structural rigidity. Viscoelastic gels based on the synthesised ChT-AA (1:3) and methylcellulose were prepared and evaluated for their rheological properties and antimicrobial performance. Rheological studies revealed non-Newtonian shear-thinning behaviour of these gels with pronounced thixotropy, confirming reversible network recovery after shear deformation. Antimicrobial evaluation of chitosan, its 4-anisaldehyde conjugate (ChT–AA, 1:3), and free 4-anisaldehyde revealed distinct activity patterns. The gels showed no inhibition in the disk diffusion assay, likely due to limited diffusion of the active components. In liquid media, both ChT and ChT–AA exhibited identical minimum inhibitory concentrations (MICs) against E. coli (0.313 mg/mL) and C. albicans (1.250 mg/mL), whereas ChT–AA showed two-fold stronger activity against S. aureus (0.313 mg/mL vs. 0.625 mg/mL for ChT). Free 4-anisaldehyde was most active against S. aureus (MIC = 0.175 mg/mL) but less effective against the other strains, confirming its narrower spectrum. These results indicate moderate antimicrobial efficacy in solution but limited activity in gel form due to restricted diffusion. Full article

Melia azedarach L. (Meliaceae) exhibits potential as a source of bioactive antibacterial compounds. In this study, the effect of solvent polarity on ultrasound-assisted extraction of M. azedarach leaves and twigs was evaluated in relation to their phytochemical composition and antibacterial activity against both non-resistant and multidrug-resistant bacteria. The results showed that solvent polarity significantly affected the extraction yield, with methanol and water producing yields above 10%. The methanol extracts of twigs and leaves exhibited the strongest antibacterial activity, showing greater potency against Escherichia coli than Bacillus subtilis. Consistent with these findings, the methanol extracts inhibited the growth of multidrug-resistant enteropathogenic E. coli K1-1, resulting in inhibition zone diameters of 10.93 mm (leaf) and 7.73 mm (twig). Furthermore, the methanol extract contained the highest levels of phenolic, flavonoid, and hydroxyl-rich compounds, which were associated with its antibacterial properties. In silico analysis further revealed that isofucosterol, meliasenin, and melianone exhibited strong predicted binding affinities to key antibacterial proteins, particularly those involved in multidrug-resistant bacterial mechanisms. Full article

Background: Escherichia coli (E. coli) bacteremia is a significant cause of mortality, particularly in older adults. Limited data exists on clinical outcomes in octogenarians. This study aims to evaluate the clinical outcomes of E. coli bacteremia in octogenarians and determine whether appropriate empirical therapy leads to improved outcomes in this specific population. Methods: We conducted a retrospective cohort study of hospitalized patients with E. coli bacteremia at Beilinson Hospital from January 2012 to December 2022. Clinical characteristics, bacteremia sources, antibiotic resistance patterns, and patient outcomes were analyzed. The primary outcome was 30-day mortality. Multivariate regression was used to assess the impact of empirical antibiotic appropriateness on mortality. Results: The study included 2717 patients, of which 1042 (38%) were 80 years or older. Older patients had more comorbidities with increased rates of ischemic heart disease (20% vs. 14%, p < 0.01) and congestive heart failure (19% vs. 9%, p < 0.01). Patients with 3rd generation cephalosporin resistant strains were more likely to receive inappropriate empiric antibiotic therapy (54% vs. 23%, p < 0.01). Although appropriate empirical therapy was associated with improved survival in univariate analysis (19% vs. 28%, p < 0.01), it was not an independent predictor of 30-day mortality in multivariate analysis [adjusted OR = 1.10, 95% CI (0.64–1.81), p = 0.7]. A lower SOFA score [adjusted OR = 0.17, CI95% (0.01–0.31), p < 0.01] was associated with decreased 30-day mortality. Hypoalbuminemia was significantly associated with increased 30-day mortality [adjusted OR = 2.49, CI95% (0.1.56–3.97), p < 0.01]. Conclusions: E. coli bacteremia in octogenarians is associated with significant mortality. While timely appropriate antibiotic therapy is crucial, mortality appears to be more influenced by overall health status, comorbidities, and infection severity. Future research should focus on addressing these factors and developing personalized care strategies to improve survival in this high-risk group. Full article

Duck viral hepatitis (DVH), a highly contagious disease, is caused primarily by duck hepatitis A virus (DHAV). The viral genotypes exhibit significant diversity, creating a challenge as monovalent vaccines fail to provide cross-genotype protection in ducklings. This study aimed to design a multi-epitope peptide vaccine targeting different genotypes of DHAV. Using immunoinformatics approaches, we systematically identified key antigenic determinants, including linear B-cell epitopes, cytotoxic T-cell epitopes (CTL), and helper T-cell epitopes (HTL). Based on these, a novel vaccine candidate was developed. The vaccine construct was subjected to rigorous computational validation: (1) Molecular docking with Toll-like receptors (TLRs) predicted immune interaction potential. (2) Molecular dynamics simulations assessed complex stability. (3) In silico cloning ensured prokaryotic expression feasibility. Then, we conducted preliminary experimental validation for the actual effect of the vaccine candidate, including recombinant protein expression in E. coli, enzyme-linked immunosorbent assay (ELISA) quantification of humoral responses, and Western blot analysis of cross-reactivity. ELISA results demonstrated that the vaccine candidate could induce high-titer antibodies in immunized animals, with potency reaching up to 1:128,000, and the immune serum showed strong reactivity with recombinant VP proteins. Western blot analysis using duck sera confirmed epitope conservancy across genotypes. Collectively, the multi-epitope vaccine candidate developed in this study represents a highly promising broad-spectrum strategy against DHAV. The robust humoral immunity it elicits, coupled with its demonstrated cross-reactivity, constitutes compelling proof-of-concept, laying a solid foundation for advancing to subsequent challenge trials and translational applications. Full article

To enhance the L-threonine synthesis level in Escherichia coli, this study constructed screening markers rich in L-threonine rare codons. By replacing all the threonine codons in the protein sequences with a high proportion of threonine with L-threonine rare codons and linking them to the fluorescent proteins with the same replacement, high-throughput screening of L-threonine production mutant strains was achieved. To address the metabolic imbalance caused by overexpression of a single enzyme, an artificial multi-enzyme complex system was constructed based on the principle of cellulosome self-assembly. By co-locating ThrC-DocA and ThrB-CohA, the substrate transfer path was shortened, achieving a 31.7% increase in L-threonine production. Furthermore, combined with multi-copy chromosomal integration technology via CRISPR-associated transposase (MUCICAT) technology, the thrC-docA-thrB-cohA gene cluster was integrated into the genome of the high-yield strains obtained through screening, eliminating the plasmid-dependent metabolic burden and significantly enhancing genetic stability. The modular assembly of metabolic pathways by using cellulosome elements provides a new paradigm for the optimization of complex pathways and lays a theoretical and technical foundation for the efficient production of L-threonine. Full article

Background/Objectives: The incidence of early-onset colorectal cancer (EOCRC) is rising worldwide, although its biological and clinical features remain incompletely understood. Emerging evidence implicates gut microbial dysbiosis as a key driver of EOCRC pathogenesis, acting through complex interactions with host genetics, mucosal immunity, and early-life exposures. This review synthesizes current evidence on EOCRC-specific microbial signatures, delineates host–microbiome interactions, and evaluates how these insights may inform precision prevention, early detection, and therapeutic strategies. Methods: A systematic literature search was conducted in PubMed, Scopus, and Web of Science up to August 2025, using combinations of “early-onset colorectal cancer,” “gut microbiome,” “dysbiosis,” and “host–microbiome interactions.” Both clinical and preclinical studies were included. Extracted data encompassed microbial composition, mechanistic insights, host-related factors, and microbiome-targeted interventions. Evidence was synthesized narratively to highlight consistent patterns, methodological limitations, and translational implications. Results: EOCRC is consistently associated with enrichment of pro-inflammatory and genotoxic taxa (e.g., Fusobacterium nucleatum, colibactin-producing Escherichia coli, enterotoxigenic Bacteroides fragilis) and depletion of short-chain fatty acid–producing commensals. Multi-omics analyses reveal distinct host–microbiome signatures influenced by germline predisposition, mucosal immunity, sex, and early-life exposures. However, substantial methodological heterogeneity persists. Collectively, these data point to candidate microbial biomarkers for early detection and support the rationale for microbiome-targeted preventive and adjunctive therapeutic approaches. Conclusions: EOCRC harbors unique microbial and host–environmental features that distinguish it from late-onset disease. Integrating host determinants with microbiome signatures provides a framework for precision prevention and tailored therapeutic strategies. Future priorities include harmonizing methodologies, validating microbial biomarkers in asymptomatic young adults, and rigorously testing microbiome-targeted interventions in clinical trials. Full article

Gleichenella pectinata, known as ‘Star fern’, is a species traditionally used by Amazonian indigenous communities to treat various diseases. The objective of this study was to evaluate the bioactive compounds and antioxidant, antimicrobial, antitumor, and anti-inflammatory activities of G. pectinata leaves. The study included the determination of physicochemical parameters (pH, soluble solids, titratable acidity, moisture, and ash), phytochemical screening, mineral analysis by atomic absorption and quantification of bioactive compounds (vitamin C, organic acids, carotenoids, chlorophylls, and phenols) by liquid chromatography (RRLC). Antioxidant (ABTS and DPPH), antimicrobial (ATCC bacteria and fungi, and multi-resistant strains), antitumor and anti-inflammatory activities were evaluated. The results showed the presence of acetogenins, high concentrations of malic acid (56,559.7 mg/100 g DW), β-carotene (266.6 mg/100 g DW), chlorophyll b (684.7 mg/100 g DW), ferulic acid (3163.5 mg/100 g DW) and quercetin glucoside (945.9 mg/100 g DW). The freeze-dried ethanolic extracts showed greater efficacy against Pseudomonas aeruginosa ATCC (12.0 mg/mL) and multidrug-resistant strains of E. coli (6.6 mg/mL) and P. aeruginosa (6.6 mg/mL). In addition, the extract exhibited moderate antiproliferative activity (IC₅₀: 0.98–1.98 mg/mL) in hepatocellular and cervical carcinoma cell lines. In conclusion, this study provides the first evidence of the antitumor and bioactive potential of G. pectinata, supporting its value as a natural source of functional compounds with potential pharmacological applications. Full article