Search Results (1,009)

Escherichia coli O157:H7 represents a major food safety concern, with cattle serving as the primary reservoir host. A better understanding of the interactions between O157 and the potential physiochemical indicators to which it is exposed to in the cattle hindgut would lend insight into the O157 colonization process and aid in the development of effective preharvest interventions to control O157 in its reservoir host. Bovine bile and oxygen are two universal cues that O157 is exposed to upon entry into the cattle hindgut and that vary between different segments of the gastrointestinal tract. Here, we exposed E. coli O157:H7 strain EDL933 to whole bovine bile powder and oxygen, both individually and in combination, and assessed the transcriptomic and phenotypic responses. Under aerobic conditions, EDL933 increased the expression of adiC, and increased biofilm production in vitro, while anaerobic conditions increased the expression of fimbrial genes, including ydeR and fimA. Bovine bile induced the expression of pathways responsible for quorum sensing and the utilization of mucus-derived sugars. These findings suggest that bovine bile and oxygen impact the transcriptomic and phenotypic characteristics of EDL933 in vitro. Full article

Shiga toxin-producing Escherichia coli (STEC) is a zoonotic pathogen of global relevance whose persistence in food processing environments is frequently mediated by biofilm formation. The acquisition of stx prophages and associated regulatory mutations can impose adaptive restrictions on this phenotype. This study analyzed 216 whole-genome sequences (WGS) to investigate the genomic determinants of biofilm formation in a diverse collection of E. coli isolates (STEC and non-STEC) isolated from cattle feedlots. Genomes were characterized for serogroup, MLST, stx subtyping, integrity of the mlrA and rpoS regulators, single nucleotide polymorphisms (SNPs) in the csg/bcs operons, antimicrobial resistance (AMR) genes, and plasmid replicons. The biofilm phenotype was quantitatively evaluated using a crystal violet assay at 15 °C for 96 h. Results demonstrated higher biofilm forming ability among non-STEC isolates compared to STEC strains, with strains simultaneously carrying both stx1 and stx2 exhibiting the lowest prevalence of biofilm formation (3.3%). Although the rpoS mutation did not show a significant overall association (p = 0.354) with biofilm formation, it was universally present across all O157:H7 isolates, and likely enhanced mlrA disruption toward csgD repression. In addition, stx-positive isolates accumulated significantly more SNPs in the curli (csg) and cellulose (bcs) structural genes. Exploratory gene-level association tests and multiple correspondence analysis further indicated that stx status was associated with broader differences in non-stx accessory gene composition. In addition, there was no statistical association between AMR classes and biofilm-forming capacity. Furthermore, STEC strains demonstrated a lower frequency of resistance to aminoglycosides, phenicols, and tetracyclines. Finally, the plasmid replicons IncX1 and IncFII(pSE11) were present and associated with biofilm-positive isolates. In conclusion, biofilm suppression in STEC suggests a multifactorial and evolutionary phage-induced regulatory trade-off, whereas biofilm persistence in non-STEC strains is independently driven by mobile genetic elements and potential accessory determinants. Full article

Background: Prosthetic joint infection (PJI) following total shoulder arthroplasty (TSA) is a rare but clinically relevant complication, largely attributable to the distinctive shoulder skin microbiome, predominantly composed of Cutibacterium acnes and coagulase-negative staphylococci (CoNS), which are considered low-virulence pathogens. Standard skin disinfection protocols do not completely prevent bacterial infiltration into the surgical field; therefore, the World Health Organization (WHO) recommends the use of intraoperative irrigation to reduce the risk of shoulder PJIs. Recently, the use of povidone–iodine (PVI) irrigation has been shown to significantly reduce both bacterial load and diversity after TSA; however, its activity against C. acnes remains suboptimal. Therefore, the aim of this study was to evaluate improved in vitro disinfection protocols by combining PVI and hydrogen peroxide for use as intraoperative irrigation in shoulder arthroplasty, which is characterized by a distinctive microbiome. Methods: In vitro broth dilution assays and time-kill experiments were performed to test PVI and H₂O₂, alone or in combination, against CoNS, Staphylococcus aureus, and Escherichia coli as representative aerobic bacteria, and against C. acnes as an anaerobic pathogen. Results: The results revealed that, when used alone, PVI exerted a more pronounced bactericidal effect against staphylococci, whereas H₂O₂ was more effective against C. acnes, even at a high bacterial inoculum, although at cytotoxic concentrations, particularly for PVI. Notably, when the disinfectants were used in combination, bacterial killing was achieved against all the tested pathogens, starting from short exposure times, mainly 3 min, and at low concentrations. Moreover, the antiseptics significantly reduced mature biofilm, although complete eradication was not achieved. Conclusions: A targeted irrigation protocol to prevent shoulder PJI can be achieved by combining PVI and H₂O₂ at non-toxic concentrations and for short exposure times that do not interfere with operating room costs or increase the risk of infection. Full article

Antibiotic resistance in Gram-negative bacteria poses a global health threat, and poultry farming provides an important reservoir for multidrug-resistant pathogens. Our study aimed to characterize the faecal microbiota and acquired resistome of Ross-308 roosters in Hungary. Amplicon and shotgun metagenomics revealed a faecal microbiota dominated by the Firmicutes, Bacteroidota, and Proteobacteria and a diverse faecal resistome, including qnrB and an aadA1-bearing integron. Culture-based screening of an antibiotic-free rooster yielded the MDR Escherichia coli strain K1G, displaying resistance also to third-generation cephalosporins and fluoroquinolones. Whole-genome sequencing classified K1G as a serotype O23:H16-ST453 avian pathogenic E. coli (APEC) strain featuring a set of chromosomal virulence factors (including astA, hlyE, lpfA, and iss) and three plasmids: a phage-like plasmid, a mosaic virulence plasmid (carrying bla_TEM-1b, hlyF, iutA, ompT, iucD, and cvaC), and an IncC type 1 resistance plasmid harbouring bla_CMY-2. The detection of identical or closely related ST453 E. coli strains also in broiler meat in Hungary highlights a potential risk of transmission to humans through the food chain. Moreover, the carriage of multiple acquired antibiotic resistance genes in E. coli K1G indicates that individual chickens can harbour or transmit antibiotic resistance even in the absence of direct antibiotic exposure. Full article

The transition toward reusable food packaging driven by European circular economy regulations introduces new food safety challenges related to microbial persistence and cross-contamination. GS-2 is a novel, food-safe antimicrobial formulation developed for use as a coating on reusable packaging materials. In the present study, the intrinsic antimicrobial activity of GS-2 was evaluated in liquid suspension against foodborne bacterial (Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella enterica Agona) and fungal pathogens (Aspergillus flavus and Aspergillus niger), and the transcriptomic response of L. monocytogenes following sublethal GS-2 exposure was investigated. GS-2 exhibited concentration-dependent microbicidal activity, with strong reductions observed at ≥2.8–3.0% against bacterial strains and A. flavus, while A. niger demonstrated resistance. Among bacteria, L. monocytogenes showed the greatest sensitivity, with populations reduced below detection limits at 3% GS-2. To elucidate mechanistic responses, RNA sequencing was performed on L. monocytogenes exposed to sublethal GS-2 concentrations (0.1–1.0%). Transcriptomic analyses using discrete and continuous models revealed a pronounced adaptive stress response at 0.5% GS-2, characterized by coordinated upregulation of pathways involved in carbon, nitrogen, and nucleotide metabolism. At higher sublethal concentrations (1%), transcriptional profiles shifted toward growth arrest and cellular damage management. These findings support GS-2 as a promising antimicrobial for enhancing the microbial safety of reusable food packaging systems. Full article

Rapid, point-of-care detection of Escherichia coli O157:H7 remains an unmet clinical need, as culture and molecular methods are slow and poorly suited to decentralized or emergency settings. A label-free, monolithic aptasensor biochip was fabricated in a standard 65 nm CMOS process, featuring three aptamer-functionalized gold sensing pads with matched reference pads for differential readout. A 37-mer DNA aptamer targeting the E. coli O157:H7 lipopolysaccharide was immobilized via thiol–gold self-assembled monolayer chemistry. Binding events were transduced into surface-potential shifts, amplified by an on-chip analog front-end (~100 V/V gain, 101.5 µW), and evaluated using calibration standards, patient specimens, and hospital environmental samples, with fluorescence microscopy for validation. The sensor achieved 47.42 mV/decade sensitivity across 1–10,000 CFU/mL, an IUPAC detection limit near 3.74 CFU/mL, and an empirical LOD of about 11 CFU/mL, with outputs tracking bacterial load and ~5.7% matrix-related deviation. Hospital samples were detectable to 28 CFU/mL. Because the patient-derived and hospital-acquired cohorts (n = 10 and n = 6, respectively) were assembled for pilot analytical and matrix-tolerance characterization rather than for diagnostic-accuracy determination, these results establish detectability and matrix robustness in real clinical and environmental specimens rather than clinical diagnostic sensitivity or specificity, which will require a larger, prospectively enrolled cohort in future work. Sensor kinetics followed Langmuir-type adsorption, saturating within 16–25 min for target pathogens versus slower responses for non-target strains. Selectivity tests against six bacterial species showed discrimination, with cross-reactivity decreasing from related E. coli pathotypes to Enterobacteriaceae to Gram-positive species. Inter-pad variability stayed below 1.5 mV, supporting this compact, low-power platform for scalable, enrichment-free point-of-care pathogen detection. Full article

Background/Objectives: Lactic acid bacteria (LAB) are essential drivers of food fermentation, yet systematic metabolic comparisons across different LAB strains remain underexplored. This study characterized and contrasted the metabolic fingerprints of Lactiplantibacillus plantarum and Lacticaseibacillus rhamnosus in vegetable fermentation and subsequently evaluated whether the same untargeted metabolomics pipeline could be applied to rapid foodborne pathogen detection. Methods: A multi-platform untargeted metabolomics strategy integrating GC-MS and UPLC-Q-TOF-MS was applied to profile four experimental conditions: non-fermented control, L. plantarum monoculture, L. rhamnosus monoculture, and mixed-culture fermentation. Multivariate statistical tools (PCA and PLS-DA) were used to identify differential metabolites and perturbed pathways. The identical analytical workflow was then applied to beef samples artificially contaminated with Escherichia coli O157:H7, Salmonella enterica, or Listeria monocytogenes. Results: Across all samples, 847 metabolites were annotated, of which 312 showed significant abundance changes upon fermentation. PLS-DA delivered robust group discrimination (R²X = 0.89, R²Y = 0.95, Q² = 0.91). Organic acids (32.0%) and amino acids (24.0%) dominated the metabolic landscape, with lactic acid, acetic acid, diacetyl, and acetoin as the most elevated compounds. KEGG analysis highlighted glycolysis/gluconeogenesis, pyruvate metabolism, and branched-chain amino acid degradation as the most heavily rewired pathways. When the same pipeline was applied to pathogen detection, it yielded AUC values of 0.89, 0.87, and 0.88 for E. coli O157:H7, S. enterica, and L. monocytogenes, respectively, with detection times of 18 h, 24 h, and 30 h. Conclusions: This work delivers a side-by-side metabolic atlas of two prominent LAB species and demonstrates the technical portability of an untargeted metabolomics pipeline from a fermentation model system to a pathogen detection scenario. The identified biomarker panels warrant further validation in diverse food matrices, and translation to routine monitoring will require matrix-specific model training and validation. Full article

Extraintestinal pathogenic Escherichia coli (ExPEC) causes severe infections in humans and animals, yet bovine isolates remain poorly characterized. Here, we report the first complete genome of a bovine ExPEC strain, BN01 (serotype O101:H9-ST10-phylogroup A), isolated from calf meningoencephalitis. Unlike classical ExPEC that typically belong to B2/D phylogroups and O1/O2/O18 serotypes, BN01 represents the A-ST10-O101 sublineage that has emerged as predominant among bovine ExPEC populations. The genome comprises a chromosome encoding 197 virulence factors, with cdiA uniquely identified in BN01 compared to six other representative ExPEC genomes—a contact-dependent growth inhibition system, and three distinct plasmids: a conjugative ESBL carrier (blaCTX-M-164, IncI1), a bovine-associated multidrug resistance island (IncY), and a mobilization-ready vector (IncFII). Animal virulence assays demonstrated that intraperitoneal challenge with E. coli BN01 caused 80% mortality (8/10 mice) within the observation period and yielded an LD₅₀ of 10^6.3 CFU/mouse. These findings demonstrate that high-risk ExPEC can occur in phylogroups typically associated with commensal strains, expanding the conventional understanding of phylogroup–virulence associations. They highlight the need to assess the zoonotic potential of livestock-associated atypical lineages and support integrated genomic surveillance under the One Health framework. Full article

Syndromic multiplex-PCR panels deliver rapid, comprehensive detection of pathogens and resistance determinants in acute infections, but their unrestricted use can generate a high proportion of negative results with substantial economic and stewardship implications. We retrospectively analysed all BioFire FilmArray meningitis/encephalitis (ME), upper-respiratory (RP2.1), pneumonia (PN) and gastrointestinal (GI) determinations performed at the UOSD Microbiology and Virology of P.O. “Vito Fazzi”, ASL Lecce (Apulia, Italy) between 1 July 2024 and 30 April 2026. Repeat determinations from the same patient with the same panel were identified in the laboratory information system and removed before any analysis, so that each determination analysed corresponds to a distinct diagnostic episode. Across 5381 determinations (CNS, n = 761; upper respiratory, n = 2601; lower respiratory, n = 399; gastrointestinal, n = 1620), 59.3% were negative for every target, with a steep appropriateness gradient: 90.0% negativity for the ME panel and 77.1% for the gastrointestinal panel versus 44.2% for the upper-respiratory and 26.6% for the pneumonia panel. CNS positives were predominantly viral (75%), led by enterovirus; Streptococcus pneumoniae was the only consistent bacterial agent. Human rhinovirus/enterovirus dominated the respiratory ecology; influenza A was almost entirely H3 and H1N1pdm09, but 8.1% of influenza-A–positive specimens were equivocal or non-subtypeable and were never referred for sequencing, an avoidable surveillance blind spot for novel/zoonotic (avian) influenza. Pneumonia-panel resistance markers (mecA/C–MREJ, CTX-M, KPC, NDM) clustered in Enterobacterales co-infections. The gastrointestinal panel was dominated by diarrhoeagenic Escherichia coli pathotypes (chiefly EPEC and EAEC) and Clostridioides difficile toxin, its 77% negativity identifying a second over-utilised stream. We argue for CSF-pleocytosis gating, tiered/reflex respiratory algorithms, gastrointestinal-panel gating to community-onset diarrhoea, and mandatory reflex sequencing of unsubtypeable influenza A. Full article

Bacterial terminal oxidases are essential for growth and may provide protection against environmental stressors. Bacteria often have to cope with ammonia, which, although an essential nutrient, is toxic at high concentrations. Here, we studied the influence of ammonia on the cell growth of three different Escherichia coli respiratory mutants, each possessing a single terminal oxidase: cytochrome bd-I, cytochrome bd-II, or cytochrome bo₃. We also investigated the effect of ammonia on O₂ consumption in cytochrome bd-II-only cells and membranes, as well as in the isolated bd-II enzyme. Using microcalorimetry, spectrophotometry and high-resolution respirometry, the following new results were obtained: (i) At pH 8.3, the addition of ammonia to both bd-I-only and bd-II-only cell cultures has virtually no effect on growth. In contrast, the growth of bo₃-only cells is significantly impaired. (ii) The addition of ammonia to bd-II-only intact cells at pH 8.3 not only fails to inhibit their respiration but also accelerates O₂ consumption. The same is observed with bd-II-only isolated membranes and detergent-solubilized bd-II enzyme. The maximum increase in cytochrome bd-II O₂ consumption rate is approximately 150%. Physiological aspects of the findings are discussed, and molecular mechanisms for ammonia-induced acceleration of O₂ consumption by cytochrome bd-II are suggested. Full article

Freshwater contamination by phosphate and pathogenic bacteria requires low-cost multifunctional treatment materials. Unlike previous studies that use a single biogenic agent to synthesize a single nanoparticle type, this work uses one fixed Aloe vera extraction protocol to generate three chemically distinct nanoparticles (Ag, CuO, Fe₃O₄) on the same waste-derived carbon support, enabling a direct, extract-controlled comparison of nanoparticle identity on water-treatment performance. Activated carbon (AC) was prepared from waste wattle bark (Acacia mearnsii) by steam activation at 700 °C and functionalized with biogenically synthesized Ag, CuO, and Fe₃O₄ nanoparticles (NPs) using Aloe vera extract as a reducing and stabilizing agent. Average nanoparticle sizes were 43 nm for Ag, 59 nm for CuO, and 13 nm for Fe₃O₄. FTIR, PXRD, SEM-EDS, TEM, DLS, TGA, and BET analysis characterized the materials. Among the composites, Fe₃O₄NPs/AC showed the best phosphate removal performance, achieving 93% removal and a maximum adsorption capacity of 9.3 mg/g under acidic conditions, compared with 3.3 mg/g for pristine AC. Equilibrium data were better described by the Freundlich model (R² = 0.999), indicating adsorption on a heterogeneous surface. Ag NPs/AC exhibited complete inactivation of both Escherichia coli and Staphylococcus aureus within 2 h, while CuO NPs/AC (a more economical alternative) achieved near-complete inactivation of both bacteria within 6 h. AC from spent wattle bark and functionalized with green-synthesized nanoparticles is thus a promising platform for combined phosphate removal and antibacterial water treatment. Consistent with their respective roles, Fe₃O₄ NPs/AC was evaluated exclusively for phosphate adsorption, while Ag NPs/AC and CuO NPs/AC were evaluated exclusively for antibacterial activity; no single composite was tested for both functions. Full article

Water-soluble blue microbial pigments with antioxidant activity remain rare, and their host-level protective mechanisms are poorly understood. Here, we identified the genetic basis of blue pigment biosynthesis in the glacier-derived strain Arthrobacter antioxidans QL17. Heavy-ion mutagenesis yielded a hyperpigmented mutant (M157) and a pigment-deficient mutant (M186), and pigment yield was positively associated with hydrogen peroxide (H₂O₂) tolerance. Genome mining identified MWM45_RS16760 as the sole core biosynthetic gene in a candidate nonribosomal peptide synthetase (NRPS)-like cluster. The encoded protein displayed an adenylation–peptidyl carrier protein–thioesterase (A-PCP-TE) architecture with a predicted L-glutamine-specific A domain, and its transcript abundance paralleled pigment production across the three strains. Phylogenetic analysis placed MWM45_RS16760 in a distinct actinomycete-associated indigoidine-like lineage separated from the characterized BpsA and IndC branches. Heterologous expression in Escherichia coli reconstructed a blue-pigment-producing phenotype, increased H₂O₂ tolerance, and was accompanied by enhanced extracellular DPPH and ABTS radical-scavenging activities in the culture supernatant. Comparative transcriptomics further revealed coordinated activation of oxidative-stress and proteostasis responses alongside repression of tryptophan biosynthesis and flagellar assembly. These findings identify MWM45_RS16760 as a candidate indigoidine-like NRPS associated with blue pigment biosynthesis and oxidative-stress resistance, with heterologous expression linked to enhanced radical scavenging and coordinated transcriptional reprogramming, expanding the phylogenetic and functional diversity of indigoidine-like systems. Full article

Objectives: Increasing antimicrobial resistance among foodborne pathogens, particularly extended-spectrum β-lactamase (ESBL) and plasmid-mediated AmpC β-lactamase (pAmpC) production, has become a major public health concern worldwide. This study aimed to determine the presence of Salmonella Enteritidis, Salmonella Typhimurium, and Escherichia coli O157:H7 in bovine carcasses and to evaluate their antibiotic resistance profiles together with ESBL and pAmpC resistance characteristics. Methods: A total of 300 bovine carcasses were examined for the presence of Salmonella spp. and E. coli O157:H7 using culture-based isolation methods following ISO 6579-1 and FDA guidelines, respectively. The isolates were confirmed by molecular methods, and stx1, stx2, eae, and hly were investigated in E. coli O157:H7 isolates. Antimicrobial susceptibility testing was performed according to EUCAST guidelines. ESBL and pAmpC production were determined phenotypically and subsequently characterized by molecular methods. Results: A total of 25 Salmonella spp. (32% S. Enteritidis and 68% S. Typhimurium) and 20 E. coli O157:H7 isolates were recovered from different bovine carcasses. stx2 was the most frequently detected virulence gene. Of the 31 phenotypically ESBL-positive isolates, 29 carried at least one ESBL-associated gene. The predominant ESBL gene was bla_CTX-M (79.3%), followed by bla_TEM and bla_SHV (37.9%). Among CTX-M gene groups, CTX-M-25 was the most prevalent (94.4%). Phenotypic pAmpC production was detected in 13 isolates, while 17 isolates carried at least one pAmpC-associated gene, with FOX identified as the predominant gene group. All isolates were resistant to pefloxacin, followed by gentamicin (93.3%) and cefoxitin (55.5%). Multidrug resistance was detected in 34 (75.6%) isolates. Conclusions: The detection of ESBL-producing, pAmpC-positive, and multidrug-resistant Salmonella spp. and Escherichia coli O157:H7 isolates in bovine carcasses indicates the presence of antimicrobial-resistant foodborne pathogens in the beef production chain. These findings highlight the need for continued monitoring of antimicrobial resistance and effective control measures at the slaughterhouse level. Full article

Most traditional photocatalysts exist in powder form and have the disadvantage of being difficult to recycle and causing secondary pollution to the environment after use. To overcome this drawback, this study combined natural biopolymer (silk fibroin (SF)) with a previously developed titanium-based photocatalytic material P/Ag/Ag₂O/Ag₃PO₄/TiO₂ (PAgT) and fabricated a novel SF/PAgT fiber membrane via electrospinning. During the synthesis process, through adjusting the mass concentration of the PAgT dopant (0–0.30 g/mL), a series of photocatalytic fiber membranes were prepared. The morphology and structure of the as-prepared membranes were characterized by various analytical methods, including scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), contact angle (CA) and thermogravimetric analysis (TGA). The SEM images confirmed that the SF/PAgT composite membrane possessed a protrusive and spindle-shaped structure. FT-IR results verified that the primary structure of SF in all the as-prepared SF/PAgT membranes belonged to the Silk II type. The binding of SF with the PAgT photocatalyst did not disrupt the chemical structure and original properties of SF. Moreover, the XRD and CA measurements indicated that the SF/PAgT-4 fiber membrane exhibited the stronger diffraction peaks of anatase TiO₂ crystal structure and enhanced hydrophilicity. The experimental results clarified that the PAgT photocatalyst was successfully loaded onto the SF fiber membrane by electrospinning. To evaluate the performance of the developed visible-light-driven photocatalytic fiber membranes, Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) were selected as representative bacteria strains. The results demonstrated that SF/PAgT-4 exhibited the optimal antibacterial activity and can completely inactivate 10⁷ CFU/mL of E. coli and S. aureus within just 30 min and 60 min treatment, respectively, indicating the optimal doping mass concentration of PAgT during the synthesis process was 0.20 g/mL. Furthermore, the scavenger study proved that during the photocatalytic disinfection process by SF/PAgT-4, all three radicals, including ·OH, h⁺ and ·O₂⁻, participated in the current photocatalytic disinfection system. They were capable of attacking the bacterial cells, causing the cell membrane injury, thereby leading to the intracellular component leakage and inducing extensive bacterial inactivation. Hence, by virtue of its excellent recyclability (during five cycles) and thermal stability (below 250 °C), the developed SF/PAgT-4 fiber membrane holds immense potential for highly efficient and sustainable utilization in practical water treatment applications. Full article

Shiga toxin–producing Escherichia coli (STEC) are important zoonotic pathogens that can disseminate through environmental water systems, yet data from Southern Italy remain scarce. The aim of this study was to investigate the occurrence and genetic characteristics of STEC isolated from surface water samples collected from rivers and lakes in the Apulia region (Southern Italy). A total of 120 samples were processed according to ISO/TS 13136:2012, followed by whole genome sequencing (WGS) for isolate confirmation and characterization. Overall, 20% of the samples were stx-positive in screening. STEC strains were isolated from 4.2% of stx-positive enrichments, corresponding to one sample out of a total of 120 (0.8%). The isolate was identified as O139:H1, carrying the stx2e subtype and belonging to sequence type ST1. Genomic analysis revealed multiple virulence-associated determinants, including the complete F18 fimbrial operon (fedA-F), hlyA, csgA, gad, chuA, yehA-D, and ompT, along with stress-resistance and tellurite-resistance genes. The strain was susceptible to all antibiotics tested. The genomic profile suggests a swine-associated lineage with multiple environmental persistence traits but limited antimicrobial resistance. The detection of a swine-associated STEC strain in surface waters highlights potential environmental dissemination pathways and underscores the importance of continued monitoring within integrated water–livestock surveillance frameworks. Full article