Foodborne pathogens and disease最新文献

Shiga toxin-producing Escherichia coli (STEC) refers to a group of bacteria that can cause infections, which are common worldwide and pose a serious public health problem, as they can lead to conditions such as hemorrhagic colitis and hemolytic uremic syndrome (HUS). HUS is a disease characterized by microangiopathic hemolytic anemia, thrombocytopenia, and renal failure. Determination of serogroups and toxin profiles of STEC is important for estimating their disease-causing potential and predicting epidemiological changes. This study analyzed STEC isolates from 46 pediatric HUS patients across Turkey, using polymerase chain reaction to determine O serogroups and Shiga toxin (Stx) variants from stool samples collected between 2016 and 2019. Of the patients, 25 (54.3%) were in the 0-2 age group. Of the isolates, 82.6% were non-O157 serogroup. The most detected serogroup was O145 (32.6%), and 28.3% of the serogroups were not typed. Of the strains, 8 (17.4%) had Stx1 alone, 26 (56.5%) had Stx2 alone, and 12 (26.1%) had both Stx1 and Stx2. The Stx variants occurred in seven combinations, with the most common being Stx2a alone (56.5%). The duration of hospitalization for patients with Stx2a was found to be longer than that for patients with other variants (p = 0.01). This study highlights a concerning trend in Turkey, where non-O157 serogroups, particularly O145, emerged as prevalent causes of HUS. The predominance of Stx2a among our isolates and the longer hospitalization duration for patients with Stx2a support findings linking this variant to severe clinical outcomes, including HUS. Understanding the dynamics of these Stx variants will help better prepare for and mitigate the impacts of STEC infections in our population.

Escherichia coli O157:H7 strains associated with several recent (2017-2020) multi-state outbreaks linked to leafy green vegetables have been characterized as "reoccurring, emerging, and persistent" (REP). Our recent unpublished work demonstrated that the REP strains had significantly enhanced potential for biofilm formation. In this study, comparative genomic analyses were conducted for a better understanding of the mechanisms behind the enhanced biofilm formation, and thereby potentially increased environmental fitness, by the REP strains. Phylogenetically, the recent outbreak strains formed two distinct clusters represented by REPEXH01 and REPEXH02. Compared with EDL933 and other previous outbreak reference strains, the REP strains (clustering with REPEXH02) exhibiting strong biofilm formation were found to have acquired two genes encoding proteins of unknown functions (hypothetical proteins) and lost certain prophage-related genes. In addition, several single nucleotide polymorphisms in genes related to biofilm formation were identified.

Vibrio vulnificus, both types A and B, in tilapia fish causes several diseases in humans-septicemia, gastroenteritis, and wound infection-that primarily occur due to the consumption of raw or undercooked fish. Using fresh tilapia fish samples collected from Riyadh market in Saudi Arabia, this study attempted to phenotypically detect V. vulnificus using specific media, such as thiosulphate citrate bile salt sucrose agar, CHROMagar™ Vibrio, and cellobiose polymyxin colistin agar, while Api 20NE was employed. Molecular detection was conducted using 16S rRNA gene sequencing, to characterize the clinical (genotype B) and environmental strains (genotype A) of V. vulnificus. Virulence genes, such as hemolysin A (VvhA) and ViuB which encodes vulnibactin siderophores, were employed to detect both strains, in addition to capsular polysaccharide (CPS) and allele 1 genes. Virulence-correlated (vcg) genes vcgC and vcgE were also considered. The multidrug resistance of both strains to different antibiotics was tested, while whole-cell protein profiles were used to examine their differences based on Sodium Dodecyl Sulphate-Polyacrylamide Gel Electrophoresis. The tilapia fish contained type A and B of V. vulnificus at a ratio of 12% and 4%, respectively. Generation times of the clinical and environmental strains were 14.45 min and 12.04 min, respectively. Analysis of the 16S rRNA, VvhA, CPS, ViuB, vcgC, and vcgE in type A and B revealed that both strains comprised all virulent genes in different ratios. Raw tilapia fish contained V. vulnificus type A and B, so care in handling is essential or during cooking these kinds of fish.

PrfA is a key virulence regulator for Listeria monocytogenes (Lm) responding to host environment. Here we report that the natural mutation in PrfA_K10N/T151A enhanced the pathogenicity of hypervirulent serotype 4h L. monocytogenes. We characterized the phylogenetic tree of PrfA, and found that PrfA_K10N/T151A prevalently distributed in all serotype 4h isolates. Remarkably, the growth rate of serotype 4h strain Lm XYSN was significantly slower than EGD-e, in contrast, the substitution mutant Lm PrfA_N10K/A151T increased the growth rate of L. monocytogenes. Notably, PrfA_K10N/T151A upregulated the expression of multiple virulent genes of Lm XYSN cultured in brain-heart infusion medium, and increased the invasion ability in HeLa and Caco-2 cells. Importantly, the PrfA_K10N/T151A mutation significantly enhanced the colonization and survival of Lm XYSN in vivo. Therefore, our findings indicate that the natural mutation of PrfA_K10N/T151A enhances the PrfA activity, resulting in the upregulation of various virulence genes and contributing to virulence and pathogenesis of Lm XYSN, which contributes to the hypervirulence of serotype 4h isolates.

Trichinellosis, a zoonotic disease transmitted through food and caused by Trichinella spiralis, is a significant health concern worldwide. Therefore, developing a safe and effective vaccine to combat T. spiralis infection is essential. In this study, a nonantibiotic Lactobacillus plantarum strain lacking the alr gene served as a live bacterial vector to deliver antigens to the host, creating a novel oral vaccine. A nonantibiotic vaccine was constructed to coexpress T. spiralis Nudix hydrolase (TsNd protein) and the gp43 protein alongside a food-grade murine IL-33 adjuvant. The objective of this study was to evaluate the efficacy of this novel strategy in preventing trichinellosis and mitigating intestinal damage. The integrated vaccination strategy was found to increase specific serum immunoglobulin G and mucosal secretory IgA (sIgA) concentration in BALB/c mice. Additionally, this approach significantly increased the release of cytokines such as interleukin-4 (IL-4) from lymphocytes, along with increased CD4⁺ expression on lymph cells from both splenic and mesenteric sources. Post-larval exposure, significant reductions in the populations of adult worms by 59.80% at 7 d postinfection (dpi) and in the larval load by 51.29% at 28 dpi were documented. Furthermore, oral vaccination reduced the number of encysted larvae present in the tongue and masseter muscles after challenge with T. spiralis. Overall, the results demonstrated that combined vaccination with the IL-33 adjuvant effectively prevented trichinellosis and reduced intestinal damage, highlighting the potential of food-grade Lactobacillus vaccines in preventing intestinal parasitic infections, with IL-33 serving as an effective adjuvant.

The increasing popularity of plant-based milk products as an alternative to traditional bovine milk has sparked concerns about their safety and nutritional impact. This study focuses on the growth, survival, and cryotolerance behavior of Listeria monocytogenes (strains: ATCC 19115 and RS1) in various plant-based milk substitutes. Samples of almond milk, oat milk, soy milk, and bovine milk, all subjected to ultra-high temperature treatment, were evaluated for their influence on L. monocytogenes growth at 4°C and survival through repeated freezing and thawing cycles. Despite the nutritional differences, the growth rates of two L. monocytogenes strains at 4°C in plant-based milk alternatives and bovine milk displayed similarity (p > 0.05). Both strains of L. monocytogenes demonstrated similar biofilm formation abilities in plant-based milk alternatives and bovine milk. However, L. monocytogenes exhibited different levels of tolerance to repeated freezing and thawing cycles depending on plant-based milk alternatives in which they were grown at 4°C (p < 0.05). In the case of L. monocytogenes ATCC19115, cells cultured in almond milk at 4°C showed a significant reduction in their freezing and thawing tolerance (2.80 log reduction), followed by cells grown in soy milk (2.09 log reduction) when compared with oat and bovine milk (p < 0.05). A parallel trend of tolerance was evident in L. monocytogenes RS1 (2.82 and 3.22 log reduction in almond milk and soy milk, respectively). These findings underscore the need for comprehensive assessments of microbial behavior in emerging food products like plant-based milk alternatives. As these alternatives continue to gain traction, ensuring their safety and stability remains important. With insights into L. monocytogenes growth and survival in milk alternatives, this study will contribute to the evolving understanding of microbial dynamics in response to changing dietary trends.

Honey is increasingly recognized as a functional food with intrinsic antimicrobial properties. Its complex chemical makeup, high sugar content, low water activity, acidic pH, hydrogen peroxide generation, and a spectrum of bioactive phytochemicals create a multifaceted defense against microbial growth, yet honey also harbors diverse microorganisms, including potential pathogens, underscoring the need for robust quality control and safety considerations across production, processing, and storage. This study synthesizes current evidence on the antimicrobial mechanisms of honey and evaluates bacterial safety concerns, with emphasis on probiotic potential and risks associated with pathogens such as Clostridium botulinum, to inform safe use and innovative functional food applications. A comprehensive review of existing literature and honey-specific data was conducted to collate chemical, microbiological, and safety-related parameters. Key antimicrobial mechanisms (osmotic pressure, acidic environment, hydrogen peroxide production, and bioactive compounds such as methylglyoxal in certain varieties) were mapped to their effects on diverse microbes. Safety considerations, contamination pathways, and regulatory frameworks were qualitatively assessed to identify critical control points. Honey's antimicrobial activity arises from synergistic interactions among sugars, pH, hydrogen peroxide, enzymes, and phytochemicals, yielding broad-spectrum inhibition. Beneficial lactic acid bacteria from honey and bees contribute probiotic potential, while the risk of contamination by pathogens necessitates stringent hygiene, processing controls, and adherence to quality standards. Processors can leverage nonthermal and thermal reduction methods to balance safety with the preservation of bioactive components. Honey remains a robust functional food with antimicrobial advantages and probiotic opportunities, provided that meticulous quality control and regulatory compliance are maintained to mitigate safety risks for vulnerable populations. Future work should optimize honey-based probiotic formulations and establish standardized safety protocols across the supply chain.

Bongkrekic acid (BA) represents an emerging food safety threat with significant public health implications. This review examines the current understanding of BA, a potent mitochondrial toxin produced by Burkholderia gladioli pathovar cocovenenans, which has caused numerous foodborne illness outbreaks with mortality rates ranging from 30% to 100%. The toxin, first identified in 1895 from Indonesian fermented coconut products (tempe bongkrek), has been implicated in over 300 cases globally, with recent outbreaks reported in China, Indonesia, Mozambique, and Taiwan. BA production occurs in fermented foods under specific conditions, including neutral pH, temperatures of 22-30°C, and high fatty acid content, particularly oleic acid. Common implicated foods include fermented corn flour, rice noodles, rehydrated mushrooms, and coconut products. As little as 1-1.5 mg can be fatal, causing gastrointestinal and neurological symptoms progressing to multi-organ failure. The toxin's unique mechanism involves inhibiting mitochondrial adenine nucleotide translocase, disrupting cellular ATP/ADP transport with no known antidote. Detection relies on chromatography and mass spectrometry, though newer ELISA and immunochromatographic methods are being developed. Prevention through proper food handling and awareness remains critical, as treatment is purely supportive. Enhanced surveillance and diagnostic capabilities are urgently needed to address this growing threat.

As a Gram-negative, microaerophilic bacterium, Helicobacter pylori (H. pylori) colonizes and thrives in the gastric mucosa. To enable early detection and treatment of H. pylori infection through exploring the clinical value of white light gastroscope endoscopic features in diagnosing H. pylori. A retrospective analysis was conducted on 968 patients who underwent routine gastroscopy over a 2-year period (March 1st, 2021-March 1st, 2023). A significant association was observed between H. pylori infection and age (p < 0.001), family history of H. pylori infection (p < 0.001), and gastric symptoms (p < 0.001). White light gastroscope findings demonstrated that diffuse erythema (p < 0.001), spotted redness (p < 0.001), mucosal swelling (p < 0.001), elongated and enlarged folds (p < 0.001), digestive tract ulcers (p < 0.001), proliferative polyps (p = 0.018), and erosions with depression (p < 0.001) were more frequent in H. pylori-infected individuals. Conversely, old bleeding spots (p = 0.003), gastric fundic glandular polyps (p = 0.048), and regular arrangement of collecting venules (RAC) (p < 0.001) were less common in H. pylori-infected patients. Diffuse erythema (odds ratio [OR] = 3.84, p = 0.002), spotted redness (OR = 2.63, p = 0.008), mucosal swelling (OR = 1.97, p = 0.007), elongated and enlarged folds (OR = 2.15, p = 0.015), digestive tract ulcers (OR = 1.49, p = 0.036), and erosions with depression (OR = 1.86, p = 0.022) were identified as independent risk factors for H. pylori infection, while the RAC served as a protective factor.

Haemonchus contortus is a highly pathogenic gastrointestinal nematode that significantly impacts ruminant health and productivity. Despite extensive research, a comprehensive understanding of the global prevalence of H. contortus infections and associated risk factors remains lacking. A systematic review and meta-analysis were conducted following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Literature on H. contortus in ruminants was retrieved from PubMed, Web of Science, ScienceDirect, Scopus, and Google Scholar up to January 1, 2025. Pooled prevalence and 95% confidence intervals were estimated using a random-effects model. A meta-analysis of 64 studies on H. contortus infection in ruminants worldwide revealed a pooled prevalence of 37%. Continent subgroup significantly influenced prevalence (p < 0.05), with the highest rate reported in Europe and the lowest in Oceania. Environmental factors played a critical role, with regions classified under the Cwb climate exhibiting significantly higher infection rates than other climate zones (p < 0.05). Higher prevalence was also associated with high-altitude areas, annual rainfall ≥800 mm, and lower temperatures. Host-related factors were equally important, with animals over 1 year of age and females showing greater susceptibility. These findings underscore the importance of developing control strategies adapted to different climates and host species, with a particular emphasis on targeted surveillance and deworming efforts against H. contortus in high-risk regions to reduce infection burden and support sustainable ruminant production.