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.
Antimicrobial-resistant enteric infections may be difficult to treat, associated with severe outcomes, and costly. To determine if resistant enteric infections are more costly, we described direct hospitalization costs for hospital admissions for typhoid fever, salmonellosis, and shigellosis infections by resistance status. We included all inpatient admissions with culture-confirmed infections from approximately 300 hospitals in the Premier Healthcare database during 2012-2019. We classified typhoid fever, salmonellosis, and shigellosis infections as clinically resistant if laboratory testing found resistance to ≥1 antibiotic class recommended for treatment. We examined patient demographic characteristics and underlying chronic conditions. We used the Wilcoxon rank sum test to assess the difference in median hospitalization cost for each patient admission by resistance status. We estimated adjusted cost and length of stay (LOS) using multivariable linear regression, adjusting for host and health care provider characteristics. Among 67 inpatient admissions for typhoid fever, 3421 for salmonellosis, and 619 for shigellosis, 33% of typhoid fever, 13% of salmonellosis, and 82% of shigellosis infections were clinically resistant. The unadjusted median costs for resistant salmonellosis were higher than susceptible infection-related costs ($7,753 vs. $6,909, p = 0.002). The unadjusted costs for resistant versus susceptible typhoid fever ($13,709 vs. $9,254, p = 0.111) and shigellosis were similar ($5,365 vs. $5,777, p = 0.167). For all three pathogens, the adjusted mean hospitalization costs were not statistically different for resistant and susceptible infections. Adjusted mean LOS was significantly longer for resistant typhoid fever compared with susceptible infections (6.50 days vs. 4.35 days, p = 0.001). Although adjusted cost differences for resistant infections were not significant, we observed differences by host factors including age and comorbidities, suggesting patient demographic characteristics for resistant infections are impactful on cost. These findings support the premise that public health interventions to limit the spread of resistant infections, particularly among individuals at higher risk for severe illness, could reduce hospitalization costs.
This study evaluated the gastrointestinal tolerance and antagonistic potential of probiotic-fermented tomato-watermelon juice formulated with Lactiplantibacillus plantarum LP01 and Bifidobacterium lactis BB12. A 75:25 (tomato: watermelon) formulation inoculated with 1.0% probiotics was selected based on physicochemical stability and viability (≥8 log10 CFU/mL). Under simulated gastrointestinal conditions, probiotic counts remained above 6 log10 CFU/mL, with intestinal counts reaching 9.71 log10 CFU/mL, and only minor reductions under gastric and bile stress. Antagonistic assay demonstrates that during 72 h storage, fermented samples effectively inhibited Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Salmonella Enteritidis, Salmonella Typhimurium, and Enterococcus faecalis in fermented samples at both 4°C and 25°C, whereas nonfermented controls supported pathogens' growth up to 8.56 log10 CFU/mL at 25°C. Probiotic populations remained ≥8 log10 CFU/mL during storage and reached approximately 8.4 log10 CFU/mL at 25°C, while fermentation reduced pH to 3.0-3.4, contributing to antimicrobial activity. These findings confirm strong gastrointestinal tolerance, sustained probiotic viability, and effective biopreservative capacity of the fermented formulation.
This study assessed global and regional incidence trends of three major enteric infections in children aged 0–14 years from 1990 to 2021. Data on diarrheal diseases (DD), typhoid and paratyphoid fever (TP), and invasive non-typhoidal Salmonella (iNTS) were obtained from the Global Burden of Disease (GBD) 2021 study. Age-standardized incidence rates (ASIRs), average annual percentage changes (AAPCs), and correlations between the socio-demographic index (SDI) and ASIRs were analyzed to characterize temporal, regional, and socioeconomic patterns. From 1990 to 2021, DD and TP declined globally, whereas iNTS showed an overall increasing trend. Globally, iNTS cases increased from 245,607 (95% uncertainty intervals [UI]: 174,385–328,774) in 1990–356,475 (95% UI: 248,066–484,385) in 2021, representing a 45.14% increase. The global AAPC of iNTS was 0.951% (95% CI: 0.763–1.140). Among SDI regions, the high-SDI region had the highest AAPC (0.733%, 95% CI: 0.390–1.078). Among GBD regions, Western Europe had the highest AAPC (2.719%), followed by high-income Asia Pacific (1.941%) and high-income North America (1.353%). At the country level, the UK had the highest AAPC (4.857%, 95% CI: 4.348–5.368). In contrast, regions with high absolute iNTS burden, such as Western sub-Saharan Africa (AAPC: −0.0399%) and Nigeria (AAPC: −0.4849%), showed declining trends. Compared with previous all-age analyses, this study provides a pediatric-specific assessment of enteric infections in children aged 0–14 years and explicitly contrasts iNTS trends with DD and TP. Although DD and TP declined substantially, iNTS showed modeled increases globally and in several high-income regions. These findings should be interpreted with caution because GBD estimates depend on data availability, diagnostic capacity, and modeling assumptions. The modeled increases in high-income regions warrant enhanced surveillance, serovar and antimicrobial resistance monitoring, and further investigation.
Typhoid fever remains a vaccine-preventable cause of childhood and adolescent morbidity in settings with limited water, sanitation, diagnostic capacity, and treatment capacity. We used Global Burden of Disease Study 2021 estimates to assess typhoid fever burden among individuals aged 0–19 years in 204 countries and territories from 1990 to 2021, with projections to 2045. We analyzed prevalence, incidence, deaths, and disability-adjusted life-years (DALYs); estimated average annual percentage changes using joinpoint regression; decomposed changes into epidemiological and demographic components; assessed Sociodemographic Index (SDI)-related inequality using the Slope Index of Inequality and Concentration Index; benchmarked countries against SDI-adjusted incidence frontiers; and projected future burden using Bayesian age–period–cohort models. Globally, the age-standardized incidence rate declined from 653.07 per 100,000 population in 1990 to 194.81 in 2021, while incident cases decreased from 14.76 million to 4.98 million. Deaths declined from 152,567 to 69,364, and DALYs from 12.93 million to 5.86 million. Despite these reductions, the burden remained concentrated in South Asia, sub-Saharan Africa, Oceania, and low- and low-middle-SDI settings. In 2021, South Asia accounted for 3.37 million incident cases, 44,095 deaths, and 3.74 million DALYs. Decomposition showed that declining age-specific rates drove global reductions, whereas population growth partly offset gains in lower-DI settings. Negative inequality indices indicated persistent concentration of burden among lower-SDI countries. Frontier analysis identified large excess-incidence gaps in South Asia, Oceania, Southeast Asia, and parts of sub-Saharan Africa. Projections suggested continued global reductions under historical-trend assumptions but persistent concentration in South Asia and widening uncertainty. Integrated typhoid conjugate vaccine scale-up, water and sanitation investment, diagnostic strengthening, and antimicrobial-resistance surveillance remain priorities for equitable typhoid control.
Salmonella enterica serovar Reading has been associated with foodborne disease outbreaks from contaminated poultry products. This study investigated the effect of S. Reading inoculation dose on Salmonella prevalence and cecal loads, and the mRNA abundance of immune response genes in turkey poults, with higher doses expected to increase colonization and elicit stronger immune responses. Day-old poults (n = 487) were assigned to four groups based on S. Reading inoculation doses of 2, 4, 6, and 8-log CFU/mL per bird, with 28 birds per pen and 4 replicate pens per treatment group. Additional poults (n = 39) were assigned to a single pen as the non-inoculated control group. On d 7, all birds were inoculated with their respective dose of S. Reading. On d 9 and d 21, the ceca, liver, and spleen were collected from 10 birds per group to assess S. Reading colonization. Cecal tonsils and spleens were collected to measure the mRNA abundance of immune response genes. On d 14, ceca were collected from 19 birds per pen (76 birds/group) to measure S. Reading loads using the SalQuant™ procedure of the BAX® PCR System. Higher doses (6 and 8-log) resulted in increased colonization of S. Reading in the ceca on d 9 (p < 0.001) and d 14 (p < 0.001), and increased prevalence of S. Reading-positive cecal samples on d 9 (p = 0.001) and d 14 (p < 0.001) compared to lower doses. The 8-log S. Reading dose resulted in greater mRNA abundance of cytokines IFN-γ (p = 0.007) and IL-10 (p = 0.037), and Toll-like receptors (TLR)-4 (p = 0.017) and TLR-15 (p = 0.002) in the cecal tonsils on d 9 compared to all other groups. Inoculation with higher S. Reading doses resulted in greater prevalence among poults and a heightened local innate immune response.
Globally, zoonotic bacterial pathogens like Salmonella spp. and pathogenic Escherichia coli remain leading causes of foodborne illness. While raw materials are critical exposure interfaces, long-term evidence regarding multi-pathogen co-contamination across food matrices is limited. We conducted a decade-long surveillance study (2016-2025) in South Korea, analyzing 4653 raw food samples-including livestock, agricultural, and marine products-for 12 zoonotic pathogens. Co-contamination was a structured, frequent feature, observed in 16.0% of livestock, 15.8% of agricultural, and 5.6% of seafood samples. Within livestock, chicken exhibited the highest co-contamination rate (27.4%), while pork showed the lowest (3.7%). Matrix-specific pathogen combinations predominated: pathogenic E. coli plus Clostridium perfringens in livestock; C. perfringens plus Bacillus cereus in agricultural products; and Vibrio parahaemolyticus plus V. vulnificus in marine products. Notably, enteropathogenic E. coli (EPEC) constituted 75.0% of pathogenic E. coli in poultry, whereas cattle showed diverse profiles including enterohemorrhagic (EHEC), enterotoxigenic (ETEC), and EPEC. Statistical analysis (Pearson's chi-square or Fisher's exact test) revealed no significant seasonal variation in contamination or co-contamination rates (all p > 0.56), suggesting that stable processing and handling factors exert more influence than climatic drivers. By conceptualizing multi-pathogen co-contamination as a reproducible feature of food systems rather than an incidental event, this study provides critical epidemiological insights into polymicrobial exposure. These findings support the transition toward multi-hazard, pattern-based surveillance and integrated risk-management strategies to enhance zoonotic foodborne disease prevention in public health systems.
Street-vended raw milk may harbor diverse bacterial communities influenced by environmental exposure, handling practices, and storage conditions. This exploratory pilot study aimed to characterize the bacterial community composition of raw milk obtained from three independent street vendors in Ankara, Türkiye, using 16S rRNA gene amplicon sequencing-based metataxonomic analysis. Following DNA extraction, the V3-V4 region of the bacterial 16S rRNA gene was sequenced, and sequence data were processed using the QIIME2 pipeline with taxonomic assignment against the SILVA 138 reference database. Sequencing generated 158,959, 160,946, and 313,696 high-quality reads for samples SS1, SS2, and SS3, respectively. The bacterial communities were predominantly composed of members of the phyla Pseudomonadota and Bacillota. At the genus level, Pseudomonas (49.75%), Acinetobacter (20.64%), Lactococcus (35.31%), Aerococcus (8.81%), and Enterococcus (7.10%) were among the predominant taxa identified across the samples. Principal coordinates analysis indicated variation in bacterial community composition among the three samples, with SS2 and SS3 exhibiting greater similarity than SS1. Overall, this exploratory pilot study provides baseline metataxonomic information on the bacterial communities associated with street-vended raw milk obtained from informal vendors in Ankara. Given the limited sample size, the findings should be regarded as preliminary descriptive observations that may support future investigations involving larger sample sizes, broader geographical coverage, and complementary functional analyses.
Tea is the second most consumed beverage worldwide, with quality largely determined by phytochemicals, particularly catechins. However, its phytobiome comprising pathogens poses a major threat to tea quality and consumers' health. The current study is designed to systematically link environmental factors and processing conditions with tea quality by integrating microbiological, physicochemical, and phytochemical analyses. The microbial contaminants from leaves, tea infusion, and water used in the cleaning of tea processing machinery were isolated and identified through morphological, biochemical characterization, 16s rRNA sequencing. Aflatoxins in the final product were examined using high-performance liquid chromatography (HPLC). Additionally, tea catechins at different tea processing stages were quantified using ultraviolet-visible spectrophotometry, Fourier-transform infrared, and HPLC. Concurrent assessment of cultivable soil and water physicochemical parameters provided insight into how environmental inputs influence both microbial load and stability of catechins during tea processing. The study revealed a gradual decrease in catechins level (71.6%) throughout different tea processing stages (p < 0.05), consistent with presence of several microbial contaminants from the tea leaves and the water samples. Among the isolates, pathogens like Acinetobacter baumannii (12 × 104 C.F.U/mL), Candida sp. (1.2 × 105 C.F.U/mL), B. zhangzhouensis (1.5 × 105 C.F.U/mL), Staphylococcus sciuri (4 × 105 C.F.U/mL), etc., were detected in tea leaves while, Penicillium sp. (4 × 102 C.F.U/mL), Alcaligenes faecalis (4.3 × 103 C.F.U/mL), and Sphingomonas paucimobilis (1.4 × 103 C.F.U/mL), etc., were isolated from water samples. However, aflatoxins were absent, and no microbial contamination was detected in the tea infusion. Phytochemical evaluation across different stages of tea processing demonstrated that variation in environmental quality and hygiene practices could modulate catechin concentration. Overall, rolling, drying, and post-processing handling were identified as critical control points, demanding regulatory monitoring to ensure both the safety and quality of green tea. Collectively, the findings establish a clear interrelationship between environmental parameters, microbial dynamics involving pathogens, and phytochemical integrity, underscoring the need for integrated environmental and HACCP-based food safety management systems across cultivation and processing.
Sodium hypochlorite (NaClO) is a widely used disinfectant in food processing to control foodborne pathogens. However, exposure to sublethal concentrations of NaClO may induce adaptive responses in bacteria, potentially affecting their persistence on food-contact surfaces. In this study, the effects of adaptation to sublethal NaClO on the biofilm-forming characteristics of Salmonella Enteritidis and the underlying regulatory mechanisms were investigated. NaClO-adapted cells exhibited significantly increased biofilm biomass on stainless steel 304 and glass compared with non-adapted cells. Compositional analysis of the biofilm matrix revealed that 48-h biofilms of NaClO-adapted cells contained higher levels of extracellular proteins, carbohydrates, and extracellular DNA (eDNA). Furthermore, adaptation to NaClO resulted in a significant reduction in motility, with swimming diameter decreasing from 7.73 ± 0.37 cm to 3.45 ± 0.42 cm. Additionally, NaClO-adapted cells exhibited enhanced cell surface hydrophobicity and a marked increase in auto-aggregation ability, with an auto-aggregation index of 39.12%, compared to 25.42% in non-adapted cells. Gene expression analysis revealed that adaptation to NaClO significantly upregulated key biofilm-related genes, including the biofilm master regulator csgD, cellulose synthase bcsA, global regulator csrA and quorum sensing luxS. In contrast, the flagellar biosynthesis gene fliA was significantly downregulated in NaClO-adapted cells, which was consistent with the observed reduction in motility. This study highlights the unintended risks related to improper NaClO application and provides critical insights for optimizing disinfection strategies to mitigate the persistence of biofilm-forming Salmonella Enteritidis and improve food safety.
Raw milk is highly prone to microbial contamination and can carry Salmonella enterica serovars-like zoonotic pathogens. This study follows the One Health-informed framework to investigate the occurrence and potential contamination pathways of Salmonella enterica serovars along the raw milk value chain in Bareilly, Uttar Pradesh, Northern India. A total of 900 samples consisted of raw milk (150), milk bucket swabs (150), milkers' hand swabs (150), and farm floor swabs (150) collected from one local dairy farm, and one institutional dairy farm, and one retail milk outlet over a 6-months period. Overall, 19 samples (2%) were Salmonella enterica serovars positive, where pathogen occurrence was noted as 4.7% in farm floor swabs, 4.7% in milking bucket swabs, and 2% in raw milk. Salmonella enterica serovars was not detected in udder swabs, towel swabs, and milker hand swabs. Antimicrobial susceptibility analysis demonstrated high Salmonella enterica serovars (n = 19) resistance to ampicillin (73.7%) and tetracycline (68.4%), whereas multiple isolates (48%) exhibited multidrug resistance as well. These findings necessitate upgraded dairy hygiene practices, controlled antimicrobial use in veterinary medicine, and integrated One Health-relevant surveillance to mitigate raw milk consumption-associated public health risks in the studied region.
The study aimed to evaluate the effectiveness of two cleaners (Tergazyme and PowerFoam Plus) and two sanitizers (Decon 7 and BioDestroy) against biofilms formed by a variety of bacterial species obtained from meat processing plants (n = 44). Biofilms were developed on polystyrene pegs at alternating temperatures of 8°C for 16 h, followed by 15°C for 8 h, over a duration of 6 days. Bacteria within biofilms were enumerated by plating, and biomass was quantified by crystal violet staining and measuring absorbance (A570). Thirty of the 44 meat plant bacterial strains formed measurable biofilms, of which 43% (n = 19) were weak biofilm formers, 9% (n = 4) were moderate biofilm formers, and 16% (n = 7) were strong biofilm formers. Of the two sanitizers, Decon 7 was the most effective at biofilm eradication (100%). The effectiveness of BioDestroy for biofilm removal was improved by a pretreatment step of PowerFoam Plus and Tergazyme. These findings show that pretreatment with cleaning products is important for improving the effectiveness of some sanitizers, and soaking equipment with cleaners prior to application of sanitizers may improve biofilm removal in meat processing environments.
Listeria monocytogenes is a significant foodborne pathogen that poses serious risks to public health and the food industry. In humans, infections can lead to severe clinical outcomes, including gastroenteritis, septicemia, meningitis, encephalitis, and pregnancy-related complications such as stillbirths and spontaneous miscarriages. Contamination of meat and meat products has been associated with numerous outbreaks and sporadic cases worldwide. The detection and identification of L. monocytogenes involve traditional microbiological and biochemical methods, as well as advanced molecular techniques, including the polymerase chain reaction and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. This review provides a comprehensive overview of the microbiological characteristics, global prevalence, and antibiotic resistance profiles of L. monocytogenes . The emergence of multidrug-resistant strains underscores the importance of ongoing surveillance, effective antimicrobial stewardship, and rigorous adherence to food safety measures. Integrated efforts across the meat production and processing chain, combined with rapid diagnostic tools and public health interventions, are crucial to reducing the risk of listeriosis and ensuring the safety of meat products globally.
Typhoid fever (Salmonella Typhi) has declined dramatically in Korea over three decades, but residual seasonality, demographic patterns and provincial spatial concentration have not been systematically reanalysed. Using all 3535 typhoid cases reported to the Korea Disease Control and Prevention Agency between 2001 and 2024 (3051 domestic and 484 imported [13.7%]), we quantified the long-term annual trend with the Hamed-Rao modified Mann-Kendall test (τ = -0.667, p = 0.0011) and a negative-binomial generalized linear model (GLM) yielding a Sen slope of -7.3%/year (95% CI -9.9 to -4.4); a parametric-bootstrap analysis of the runner-up 1-breakpoint GLM identified 2018 as the most likely structural change point (95% CI [2009, 2022]). A continuous Morlet wavelet transform of the weekly series revealed annual periodicity that exceeded a 1000-simulation AR(1) red-noise null by a factor of 2.60. Direct age standardization and age-band-specific Mann-Kendall tests showed statistically significant declines in every age stratum. Provincial spatial analysis (16 sido) gave a global Moran's I of 0.403 (p = 0.0083, 9999 permutations) under a Queen + k-nearest-neighbor-2 baseline scheme, with the southeastern coastal cluster (Gyeongnam-Busan-Ulsan-Gyeongbuk axis) preserved across 12 alternative weighting schemes after empirical Bayes shrinkage of sigungu-level rates and across two equal-length time strata; one province (Ulsan) survived Benjamini-Hochberg FDR adjustment of the 16 LISA p-values. Korean typhoid has continued its long-term decline; residual incidence concentrates in the southeastern coastal corridor, and imported cases-including ciprofloxacin-resistant H58 strains from South Asia-now form a substantial fraction of notifications, motivating pre-travel counseling and post-travel vigilance.
Animal-derived foodstuffs are essential for human nutrition but may harbor pathogens responsible for foodborne diseases. In Maghreb countries (Algeria, Libya, Morocco, and Tunisia), data on foodborne pathogen hazards are often limited and fragmented. To address this gap, the present systematic review and meta-analysis aimed to estimate the overall prevalence of foodborne pathogens in animal-derived foods in the Maghreb region from 2004 to 2025. A systematic literature search was conducted in two electronic databases (PubMed and Scopus) following PRISMA guidelines. A total of 80 studies met the inclusion criteria. Data were analyzed using the meta package in R software, applying a random-effects model. The pooled prevalence of pathogens in foods of animal origin was 26.6% (95% CI: 20.0-33.8), with high heterogeneity (I2 = 98.9%). The highest contamination was observed in raw poultry meat (36.1%). Eleven foodborne bacterial species were reported. Salmonella spp. was the most frequently reported (n = 18), with a pooled prevalence of 14.2%, followed by Staphylococcus aureus (28.3%, n = 16) and Escherichia coli (36%, n = 16). Most studies were conducted in Algeria and Morocco, with country-level prevalence ranging from 22.1% to 38.1%. This review reveals a substantial burden of foodborne pathogens in the Maghreb region. Enhanced surveillance and targeted control measures are essential to improve food safety and protect public health.
Staphylococcus aureus, a common cause of bovine mastitis, relies on several virulence factors, with biofilm formation being a key contributor to its pathogenicity. The present study investigated the occurrence of S. aureus as etiological agents in bovine mastitis with a focus on the existence of various virulence factors and antibiotic resistance status. Among 120 milk samples collected from West Bengal and Uttar Pradesh, 36 (30%) S. aureus strains were confirmed by conventional methods and PCR. Phenotypic analysis revealed hemolysin (55.55%) and coagulase production (36.11%), while molecular analysis revealed the presence of leukotoxin (luksF, 19.44%), hemolysin (hlb, 58.33%), coagulase (coa, 63.88%), and toxic shock syndrome toxin (tsst-1, 30.55%) genes. Biofilm production ability was detected in 97.22% (crystal violet assay) and 86.11% (Congo red agar assay) strains. Biofilm-associated genes, namely, icaA (80.55%, 29/36), icaB (75%, 27/36), icaC (69.44%, 25/36), icaD (86.11%, 31/36), and MSCRAMMs genes, namely, clfA (58.33%, 21/36), clfB (75%, 27/36), fnbA (75%, 27/36), fnbB (55.55%, 20/36), bap (38.88%, 14/36), bbp (83.33%, 30/36), ebps (69.44%, 25/36), eno (66.66%, 24/36), fib (41.66%, 15/36), and cna (8.33%, 3/36), were also detected. Antimicrobial resistance was observed in 88.88% isolates, with 72.22% exhibiting multidrug resistance (MDR). Among the isolates, 83.33% were methicillin-resistant S. aureus (MRSA), and mecA, femA, and femB genes were present either singly or in combination in 76.66% of the isolates. Efflux pump protein genes, namely, norA, norB, norC, mdeA, mepA, and sepA, were detected either singly or in combination in S. aureus isolates. 61.53% of MDR-MRSA isolates harbored all six efflux pump genes. According to this study, S. aureus of mastitis origin harbors various virulence, antibiotic resistance, biofilm-forming, and efflux pump genes. Bovine mastitis-derived MDR S. aureus isolates can pose a significant public health risk and need urgent attention to formulate strategies for their control and preventing transfer to the human food chain.
Cronobacter sakazakii, an opportunistic foodborne pathogen associated with powdered infant formula, causes severe neonatal infections, yet its interaction with gastric epithelial cells remains poorly characterized. Here, we conducted a preliminary in vitro study to evaluate early host-pathogen responses of C. sakazakii in AGS gastric epithelial cells. AGS cells were exposed to C. sakazakii ATCC 29544 at a multiplicity of infection of 100 for 2 h, and cytotoxicity and transcriptional responses were assessed by viability assay, gentamicin protection assay, and reverse transcription-quantitative polymerase chain reaction. Infection significantly reduced AGS cell viability and increased expression of bacterial virulence-associated genes (ompA and hfq) and host inflammatory genes (IL-8 and NF-ƙB) compared with mock-infected controls (p < 0.001). Gentamicin-protected recovery was consistent with bacterial entry into AGS cells, although confirmatory imaging-based analyses were not performed. These findings indicate that C. sakazakii (ATCC 29544) can elicit early cytotoxic and pro-inflammatory responses in AGS gastric epithelial cells under in vitro conditions, supporting the need for confirmatory studies in more physiologically relevant gastric study models.
Campylobacter jejuni and Campylobacter coli are leading causes of foodborne gastroenteritis worldwide, with poultry representing the primary reservoir for human infection. Understanding species-specific differences in virulence-associated features, antimicrobial resistance genes, and population structure is essential for assessing public health risks and guiding surveillance strategies. A total of 26 Campylobacter isolates (22 C. coli and 4 C. jejuni) were recovered in 2023 from poultry caeca collected from farms in north-western, central-western, and south-western Romania. Species identification and detection of the hcp gene, a marker of the type VI secretion system (T6SS), were performed using multiplex PCR. Multilocus sequence typing (MLST) based on seven housekeeping genes was performed to evaluate genetic diversity and population structure. The hcp gene was detected exclusively in C. jejuni isolates, indicating that it was detected only in C. jejuni within this collection of the primary T6SS component. Both species shared a broad set of core virulence genes related to motility, colonization, quorum sensing, adhesion, and surface polysaccharide biosynthesis, while notable differences were observed in accessory virulence gene profiles. Genes associated with antibiotic resistance, including the tetracycline resistance gene tet(O) and multiple efflux-related determinants, were frequently detected in both species. MLST analysis revealed high genetic diversity, with most isolates not assignable to previously defined sequence types, consistent with an open pan-genome and substantial genomic plasticity. These findings feature clear differences between C. jejuni and C. coli in the distribution of virulence markers, while validating the widespread presence of antimicrobial resistance genes in poultry-associated isolates. This study highlights the adaptive potential of Campylobacter and underscores the need to advance molecular surveillance to monitor virulence and antimicrobial resistance risks relevant to animal and human health.
