With evolving lifestyles, consumer demand for fresh fruits and vegetables has increased. However, these products are susceptible to contamination by foodborne bacteria from farm to table. To investigate the contamination status of foodborne bacteria in commercially available fresh fruits, vegetables, and their ready-to-eat (RTE) products in Shijiazhuang City, a total of 406 samples were collected from 2024 to 2025. Staphylococcus aureus (S. aureus), Clostridium perfringens (C. perfringens), diarrheagenic Escherichia coli (diarrheagenic E. coli), and Salmonella were identified and analyzed for genomic characteristics using traditional biochemical tests and whole genome sequencing (WGS). The results showed that the detection rate of S. aureus was 4.68% (19/406), of which 5 isolates were identified as methicillin-resistant S. aureus (MRSA), accounting for 1.23% (5/406). The detection rate of C. perfringens was 8.37% (34/406), and the detection rate of diarrheagenic E. coli was 0.25% (1/406). No Salmonella was detected. Genomic characterization revealed that S. aureus strains were predominantly ST59 and ST22, with the MRSA strains primarily identified as ST59-SCCmec-IVa (2B)-t437. A total of 20 enterotoxin genes were detected, with 94.74% (18/19) of the strains carrying at least one enterotoxin gene. The sea gene was the most prevalent (52.63%, 10/19), and the tsst-1 gene, which can cause toxic shock syndrome, was detected in 2 strains. C. perfringens isolates were divided into 30 STs, exhibiting high genetic diversity. All toxin types were classified as type A. The mprF gene showed the highest carriage rate of resistance genes (94.12%, 32/34), and the main resistance profile was mprF + cplR (55.88%, 19/34). The diarrheagenic E. coli isolate was identified as enterotoxigenic E. coli (ETEC) and carried multiple antimicrobial resistance genes. This study systematically reveals the contamination levels and molecular characteristics of common foodborne bacteria in fresh fruits, vegetables, and their RTE products sold in Shijiazhuang for the first time.

Thermal processing inactivates foodborne bacteria but does not necessarily destroy their DNA, membrane vesicles, or bacteriophage particles. Such residues persist in pasteurized milk and heat-treated meat and are ingested by consumers. Whether this material can transfer antimicrobial resistance genes (ARGs) to gut bacteria remains untested: the only direct human evidence of foodborne resistance-gene transfer involved live bacteria, not material released from heat-killed cells. This narrative review synthesizes evidence on the post-thermal fate of extracellular DNA, membrane vesicles, and bacteriophages, grading that evidence explicitly from detection of a target sequence, through structural integrity, to demonstrated transfer under realistic conditions. Persistence of ARG sequences after pasteurization is well documented, whereas functional transfer from foodborne dead-cell material has not been demonstrated in vivo. A Genetic Legacy Index (GLI) is proposed as a conceptual measurement framework-not a validated index-combining extracellular DNA abundance, ARG load, and ARG-mobile genetic element linkage, with an illustrative formula, normalization strategy, and validation agenda. Current finished-product microbiological criteria are predominantly culture-based and do not establish limits for extracellular or dead-cell genetic material, although integrated antimicrobial resistance surveillance increasingly includes molecular detection and whole-genome sequencing. The GLI is therefore proposed as a research and surveillance tool rather than a product-release criterion: a first step toward evaluating an unquantified exposure pathway within One Health surveillance of the food chain.

This study investigated the intestinal carriage of extended-spectrum cephalosporin-resistant (ESC-R) Enterobacterales in farmed sea bream (Sparus aurata) marketed in Algiers. A total of 108 intestinal samples were collected from seven fishmongers between 2023 and 2024. ESC-R Enterobacterales were detected in 16.7% of the samples (18/108), including Klebsiella pneumoniae (n = 9), Escherichia coli (n = 8), and Klebsiella michiganensis (n = 1). Whole-genome sequencing confirmed the presence of genes conferring an extended-spectrum β-lactamase phenotype in 17 isolates (mostly blaCTX-M-15) and an AmpC cephalosporinase phenotype in one isolate. Moreover, the mcr-1.1 and fosA3 genes, which respectively confer resistance to colistin and fosfomycin, were detected in a single E. coli isolate. To the best of our knowledge, this is the first report of plasmid-mediated colistin resistance in Algerian aquaculture. Most isolates (72.2%) exhibited a multidrug-resistant (MDR) phenotype, mainly involving resistance to tetracyclines, sulfonamide-trimethoprim, and streptomycin. Several sequence types (STs) identified in this study, including the high-risk clones E. coli ST131 and K. pneumoniae ST37, have previously been reported in humans and animals. In addition, two ESC-R Aeromonas caviae isolates were recovered. These findings demonstrate the occurrence of ESC-resistant bacteria in the intestinal microbiota of farmed sea bream marketed in Algiers and underscore the need for integrated One Health surveillance to better understand the role of aquaculture in the emergence, maintenance, and dissemination of MDR bacteria and antimicrobial resistance determinants.

The aim of this study was to characterize invasive listeriosis in Türkiye and identify predictors of in-hospital mortality. This multicenter retrospective observational study included adult patients with laboratory-confirmed Listeria monocytogenes infection from 26 centers between 2015 and 2024. Clinical, demographic, laboratory, and treatment data were collected. Patients were classified based on infection type. Univariate analyses were followed by multivariable logistic regression to determine independent predictors of mortality. A total of 129 patients were included (mean age 62.1 ± 16.9 years; 65.9% male). The in-hospital mortality rate was 54.8%. Deceased patients were older and had more frequent comorbidities. Bacteremia without central nervous system involvement was more common among nonsurvivors. Lower Glasgow Coma Scale (GCS) scores, lower platelet counts, higher CRP levels, and more frequent blood culture positivity were observed in patients who died. In multivariable analyses, higher GCS scores were associated with lower odds of mortality (adjusted odds ratio [OR] 0.71 per 1-point increase, 95% confidence interval [CI] 0.59-0.86), as were higher platelet counts (adjusted OR: 0.94 per 10,000/µL increase, 95% CI: 0.89-0.99), whereas blood culture positivity was associated with higher odds of mortality (adjusted OR: 3.19, 95% CI: 1.04-9.82). Invasive listeriosis is associated with high mortality in Türkiye. Admission GCS score, platelet count, and blood culture positivity were independently associated with mortality and may help identify patients at increased risk of death.

Streptococcus agalactiae (Group B Streptococcus) is a leading causative agent of sepsis, pneumonia and meningitis in neonates and is also a major pathogen responsible for bovine mastitis, posing a substantial threat to food safety and public health via the dairy production chain. The ability of S. agalactiae to form biofilms in the host enhances its resistance to conventional antibiotics and host immune defenses, thereby contributing to persistent and chronic infections. This study aimed to evaluate the antibacterial, antibiofilm, and combined antibacterial effects of dihydromyricetin (DMY) against the S. agalactiae strain GBS2 isolated from bovine mastitis. DMY exhibited significant antibacterial activity against GBS2, with a minimum inhibitory concentration and minimum bactericidal concentration of 0.5 mg/mL. Crystal violet staining and confocal laser scanning microscopy analyses demonstrated that DMY effectively inhibited and disrupted biofilm formation, resulting in looser and less dense biofilm structures compared to untreated controls. Furthermore, reverse transcription-quantitative PCR (RT-qPCR) results revealed that DMY modulated the transcript levels of biofilm-associated genes (csrR, srtA, fbsC, cpsE, and luxS). Additionally, DMY markedly potentiated the antibacterial effect of penicillin G, ciprofloxacin, oxacillin, and vancomycin. These findings suggest that DMY could serve as a natural antibiofilm agent for controlling S. agalactiae contamination in the dairy industry, thereby contributing to the prevention of foodborne infections and reducing reliance on conventional antibiotics.

Shiga toxin-producing Escherichia coli (STEC), a zoonotic foodborne pathogen, has become a critical global public health issue. This study investigates molecular traits and antimicrobial resistance (AMR) mechanisms of STEC strains derived from retail meat products sourced from domestic production in Liaocheng city, Shandong province, China, to inform health risk assessment. Using quantitative real-time polymerase chain reaction (qPCR), phenotypic AMR testing, and whole-genome sequencing (WGS), 38 STEC isolates were identified from 400 retail meat products, with an isolation rate of 9.5%. Significant differences in STEC isolation rates were detected among different meat types, and mutton exhibited a relatively high isolation rate of 26.09%. Genomic virulence analysis showed that there were higher proportions of single stx2 (58.33%) and dual stx1/stx2 genotypes (33.33%) in mutton isolates than in beef (stx2: 48.00%, dual stx1/stx2: 12.00%), and only the stx2 gene was found in pork isolates. STEC isolates exhibited marked serotypic diversity, including O128ac:H2, O168:H7, O178:H7, O2:H25, and O6:H10. Multilocus sequence typing analysis revealed heterogeneous sequence type (ST) distributions among isolates, with ST10, ST25, and ST2722 as dominant STs, suggesting diverse contamination sources. STEC isolates exhibited high phenotypic resistance to tetracycline (TET) (68.42%), which corresponded to the highest detection rate of the TET resistance gene tet(A) at the genomic level. All isolates were susceptible to ertapenem, meropenem, ceftazidime, ceftazidime-avibactam, ciprofloxacin, and amikacin. Multidrug resistance (MDR) analysis indicated that 16 STEC isolates were MDR strains, with beef-derived isolates having relatively high MDR rates. This study verifies the occurrence of STEC in retail meat, highlighting prevalent AMR and substantial genetic heterogeneity among isolates. The findings underscore the necessity of systematic surveillance to limit STEC transmission along the meat supply chain and facilitate targeted food safety interventions.

Standardized antimicrobial susceptibility assays use defined culture media and may therefore not fully account for gastrointestinal constituents that influence bacterial responses to antibiotics. This study evaluated whether swine fecal extracts, including extracts associated with dietary chlorophyllin supplementation, altered the antimicrobial susceptibility of multidrug-resistant Gram-positive bacteria. Fecal material collected from pigs fed either a non-chlorophyllin or chlorophyllin-supplemented diet was pooled by dietary group, processed to produce clarified fecal extracts, and incorporated at 20% (vol/vol) into Mueller-Hinton (MH) broth. Minimum inhibitory concentrations (MICs) of chlortetracycline, penicillin, carbadox, tylosin, ceftazidime, and norfloxacin were determined for selected Staphylococcus, Streptococcus, and Enterococcus strains using broth microdilution and compared with MICs obtained in standard MH broth. Fecal extracts altered MICs in a strain- and antibiotic-dependent manner. Extracts from chlorophyllin-fed pigs produced particularly pronounced reductions in susceptibility thresholds for several combinations, including >128- to >256-fold decreases in chlortetracycline MICs for Streptococcus agalactiae, Staphylococcus hyicus, and Enterococcus faecium H 1019 V; >253-fold decreases in penicillin MICs for several strains; and >32- to >256-fold decreases in ceftazidime MICs for four strains. Carbadox MICs were also reduced in several organisms. However, these effects were not universal: tylosin MICs were generally unchanged or increased, and norfloxacin MICs were unchanged or increased in all strains tested. Fecal extracts from non-chlorophyllin-fed pigs also altered MICs, demonstrating that the fecal matrix itself influenced phenotypic antimicrobial susceptibility. These findings indicate that antimicrobial susceptibility measured under standard laboratory conditions may differ substantially in the presence of fecal-derived constituents and support further characterization of the metabolites responsible for these effects.

Food-animal surveillance can identify antimicrobial-resistance patterns that may affect foodborne disease risk, but pooled summaries can obscure commodity and serotype drivers. This study analyzed public FSIS NARMS cecal and HACCP/slaughter-source Salmonella records accessed through FDA NARMS Now to examine quinolone-resistance trends by calendar period, commodity, and serotype. Records were filtered to Salmonella isolates with reported growth collected from 2013 to 2023. Calendar periods were defined descriptively as 2013-2016, 2017-2022, and 2023 to bracket major U.S. antimicrobial-stewardship milestones, including completion of GFI #213 implementation in 2017 and implementation of GFI #263 in 2023; these periods were treated as temporal landmarks rather than causal policy exposures. Outcomes were ciprofloxacin non-susceptibility, ciprofloxacin resistance only, and nalidixic acid resistance. Analyses included commodity-stratified percentages with Wilson 95% confidence intervals, serotype contribution summaries, and binomial models with standard errors clustered by year. The dataset included 42,232 Salmonella isolates; 41,608 were tested for ciprofloxacin and 41,606 for nalidixic acid. Overall, ciprofloxacin non-susceptibility increased from 1.96% in 2013-2016 to 17.84% in 2017-2022 and 25.71% in 2023. Nalidixic acid resistance increased from 1.36% to 17.02% and 24.01%, respectively. These increases were concentrated in chickens, where ciprofloxacin non-susceptibility rose from 1.7% to 28.7% and 42.4%. Salmonella Infantis accounted for 75.0% of all ciprofloxacin non-susceptible isolates, and Infantis plus Enteritidis accounted for 85.6%. After excluding both serotypes, adjusted period odds ratios were substantially attenuated. Findings indicate that quinolone-resistance trends in FSIS NARMS food-animal Salmonella data were strongly shaped by chicken-associated serotype composition, supporting serotype-aware surveillance.

Salmonella spp. are major foodborne pathogens transmitted through contaminated poultry products. The emergence of antibiotic-resistant strains complicates treatment and increases the risk of multidrug-resistant (MDR). In Morocco, data on antimicrobial resistance (AMR) profiles in poultry-associated Salmonella remain limited. This study aimed to assess the prevalence and AMR patterns of Salmonella spp. isolated from poultry samples collected in Morocco in 2023. A total of 1339 poultry samples (ceca, turkey, and chicken meat) were collected using a representative stratified sampling approach from slaughterhouses, farms, and retail markets across the 10 regional directorates of Morocco. The isolation of Salmonella spp. was performed according to ISO 6579-1:2017, and identification was confirmed via matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry. Antimicrobial susceptibility to 15 antibiotics was evaluated using Sensititre EUVSEC3 plates. Minimum inhibitory concentrations (MICs) were interpreted according to epidemiological cutoff values established by the European Committee on Antimicrobial Susceptibility Testing. MDR was defined as resistance to at least one antimicrobial agent in three or more antibiotic classes. Salmonella spp. were detected in 155 out of the 1339 samples, with an overall prevalence of 11.6% and regional variation. The category-specific prevalence was 13.8% (48/348) for chicken meat, 12.3% (45/367) for turkey meat, and 10.0% (62/624) for cecal samples. Resistance to nalidixic acid (94.2%), ciprofloxacin (92.3%), tetracycline (63.9%), ampicillin (36.8%), trimethoprim (27.7%), chloramphenicol (16.1%), gentamicin (10.3%), cefotaxime (4.5%), amikacin (3.9%), and ceftazidime (0.6%) was detected, whereas resistance to meropenem was not detected. Overall, 69.7% of the isolates were classified as multidrug-resistant and were mainly resistant to quinolones, tetracyclines, and beta-lactams. These findings highlight the need for strengthened antimicrobial stewardship, improved surveillance, and stricter regulation of antibiotic use in poultry production to reduce public health risks.

Shiga toxin (Stx) is the main virulence factor of enterohemorrhagic Escherichia coli. Between its two types-Stx1 and Stx2-E. coli O157:H7 produces Stx2, which causes more severe infections compared with Stx1 or both Stx1 and Stx2. In this study, we isolated and identified E. coli O157:H7 from frozen raw beef samples and both Stx1 and Stx2 from frozen raw beef liver samples collected from the Al-Riyadh market in Saudi Arabia. Phenotypic detection was conducted using suitable and specific media-sorbitol MacConkey agar and Salmonella chromogenic agar-with E. coli O157:H7 appearing as colorless and blue-colored colonies, respectively. Furthermore, serological testing using DrySpot E. coli O157 latex agglutination tests was conducted to verify the identification and detection results. A conventional polymerase chain reaction was conducted using specific primers of the genes encoding Stx1 and Stx2 for further verification. The results showed that among the 50 frozen raw beef meat samples, 11 colonies harbored the stx2 gene with an amplicon of 420 bp (22%). Meanwhile, among the 50 frozen raw beef liver samples, 5 samples harbored either both the stx1 and stx2 genes or the stx2 gene alone, with amplicons of 310 and 420 bp, respectively (10%), while 6 samples harbored only the stx2 gene (12%). Overall, E. coli O157:H7 containing Stx2 was prevalent in beef meat, while Stx1 and/or Stx2 were identified in beef liver. Furthermore, E. coli O157:H7 harboring stx2 genes were found to be more resistant to different antibiotic classes (50%) than strains containing stx1 and/or stx2 genes (42.28%). Moreover, doubling time in tryptic soy medium extended to 60 min for strains harboring stx2 alone and 55 min for strains harboring stx1 and/or stx2. In conclusion, E. coli O157:H7 was found to be considerably more multidrug resistant than Stx1 and/or Stx2 with respect to several conditions and circumstances.

Listeria monocytogenesis an important foodborne pathogen that can cause severe invasive disease in vulnerable populations. This study assessed the occurrence of L. monocytogenes in animal-derived foods collected in Bejaïa, Algeria, and characterized recovered isolates using whole-genome sequencing (WGS). A total of 553 samples (red meat, minced meat, sausage, chicken carcasses, raw milk, and artisanal butter) were analyzed using ISO 11290-based culture, with species confirmation by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Twenty-two isolates were recovered (overall prevalence 4% ± 1.6), with the highest positivity in chicken carcasses (10.9% ± 5.8, 12/110) and artisanal butter (12.5% ± 16.2, 2/16). All isolates belonged to sequence type ST121 and carried the same plasmid replicon rep26. No acquired antimicrobial resistance genes were identified in any isolate. Screening of virulence-associated loci indicated genomic carriage of all conserved set of loci. A truncation in inlA gene was present, which has been associated with decreased virulence pattern. These findings highlight the occurrence of L. monocytogenes in multiple animal-derived products in Bejaïa and support the integration of WGS into routine food-chain surveillance.

In this study, 327 retail raw meat samples collected from five cities were examined for Staphylococcus aureus, and 92 isolates recovered from 73 positive samples were further characterized for classical enterotoxin genes and toxin production, antimicrobial susceptibility, biofilm formation, and molecular typing. S. aureus was detected in 22.3% of samples (73/327), with positivity varying across the sampled cities and meat types. Classical enterotoxin genes were detected in 10.9% of isolates (10/92), and 9 of the 10 gene-positive isolates produced at least one detectable classical enterotoxin. Resistance was highest to penicillin (94.6%), erythromycin (71.7%), tetracycline (59.8%), and clindamycin (58.7%); 80.4% of isolates were multidrug-resistant, and 19.6% carried the mecA gene. Moderate or strong biofilm formation was observed in 93.5% of isolates. Among a purposively selected subset of 41 isolates used for molecular typing, spa type t236 and pulsed-field gel electrophoresis cluster P2 were the most frequently observed profiles. Overall, retail raw meat sampled in Northern Xinjiang harbored S. aureus with confirmed toxigenic potential in a subset, frequent multidrug resistance, and widespread biofilm-forming ability. Together, these results provide an integrated evidence base for prioritizing antimicrobial resistance and toxin surveillance alongside hygiene control in retail meat systems.

Bacillus cereus is an endospore-forming opportunistic pathogen with global distribution, responsible for two distinct gastrointestinal illness types. The present study aimed to determine the occurrence of B. cereus in ready-to-eat (RTE) foods marketed in Samsun, Turkey, and to characterize confirmed isolates with respect to enterotoxin gene carriage, capacity for psychrotrophic growth, and antibiotic susceptibility profiles. One hundred fifty RTE food samples were examined, including spicy paste (acılı ezme, n = 29) Russian salad (rus salatası, n = 44), raw meatballs (çiğ köfte, n = 42), and stuffed grape leaves (yaprak sarma, n = 35), procured from retail outlets and food service establishments between December 23, 2024, and February 28, 2025, and analyzed in accordance with TS EN ISO 7932:2004. B. cereus was recovered from 30.6% (46/150) of samples overall, with the greatest contamination frequencies recorded in spicy paste (62.1%, 18/29) and çiğ köfte (57.1%, 24/42). Viable counts in contaminated samples fell within the range of 1.0 × 10[1] to 4.1 × 10[3] colony-forming units (CFU)/g. Multiplex polymerase chain reaction screening of the 46 confirmed isolates showed that 28.2% (13/46) carried at least one enterotoxin gene; hbl, nhe, and cytK were each identified in 13.0% of isolates, whereas the emetic toxin gene ces was not detected in any isolate. Ability to proliferate at 7°C was demonstrated in 52.2% (24/46) of isolates. Kirby-Bauer disk diffusion testing revealed that all isolates (100%) were resistant to penicillin, with resistance also recorded for ampicillin (38.5%), tetracycline (30.8%), and clindamycin (23.1%). Collectively, these findings underscore the public health relevance of enterotoxin-carrying, cold-tolerant, and antibiotic-resistant B. cereus in RTE foods and emphasize the necessity of strengthening temperature management and sanitation measures at all stages of the food supply chain.

Meteorological factors may influence the risk of foodborne diseases (FBDs), but evidence comparing different case definitions and pathogen-specific associations within the same surveillance system remains limited. This study aimed to investigate the relationship between short-term exposure to meteorological factors and FBDs in Ningbo, China. We used data from the Ningbo Foodborne Disease Surveillance System and the daily meteorological data of the Ningbo Meteorological Bureau for time-series analysis. Generalized additive models and distributed lag nonlinear models were used to evaluate the associations adjusted for long-term trends, seasonal changes, day of week, and holidays. A stratified analysis was carried out by sex, age, and pathogens. We found that short-term temperature rise was significantly associated with risk of clinically diagnosed FBD cases (mean: relative risks [RR] = 1.028, 95% confidence interval [CI]: 1.006-1.049; minimum: RR = 1.025, 95% CI: 1.004-1.047). Sex- and age-stratified analyses indicated positive temperature associations in both sexes and in several age groups between 15 and 64 years. Pathogen-specific analyses show that there is a positive relationship for Vibrio parahaemolyticus (mean temperature: RR = 1.087, 95% CI: 1.021-1.157), whereas an inverse relationship for Norovirus (mean temperature: RR = 0.965, 95% CI: 0.938-0.993). The findings remained robust in sensitivity analyses. These findings may inform targeted seasonal and pathogen-specific surveillance.