Foodborne pathogens and disease最新文献

Toxoplasma gondii is a ubiquitous parasitic protozoan that can cause neurological and psychiatric disorders, potentially impacting human emotional behavior. This study aimed to explore serological and molecular evidence of T. gondii infection in opioid abusers in northern Iran. In this case-control study, opioid abusers who were referred to substance abuse rehabilitation centers in Mazandaran Province, northern Iran, were enrolled. Blood samples were collected from the participants to perform a serological assay to detect T. gondii IgG and IgM antibodies. A polymerase chain reaction (PCR) test was also conducted on buffy coats of the blood samples. The study comprised a total of 474 participants, with 239 individuals being opioid abusers and 235 healthy individuals serving as the control group. The results indicated that 163 opioid abusers (68.2%) were positive for T. gondii IgG, whereas 76 (31.8%) were negative. Among the control group, 63 individuals (26.8%) tested positive for T. gondii IgG, whereas 172 (73.2%) tested negative. This difference was statistically significant according to p = 0.01, odds ratio (OR) = 2.67, and 95% confidence interval (CI) = 1.03-4.15. In addition, 7.1% (17/239) of the case and 2.1% (5/235) of the control groups were PCR positive for Toxoplasma DNA. This difference was statistically significant (p = 0.01; OR = 2.96; 95%; CI = 0.94-7.01). In contrast, all of the participants were negative for T. gondii IgM antibodies. Our findings demonstrated that the sero-molecular prevalence of latent T. gondii infection in opioid abusers is significantly higher than that in healthy individuals. This suggests a potential correlation between T. gondii IgG antibody positivity and PCR results with opioid abuse.

Salmonella Infantis has recently been one of the most prevalent serotypes in poultry and has been identified in human salmonellosis cases worldwide. Multidrug-resistant (MDR) Salmonella Infantis has emerged as a significant threat to both poultry production and public health due to its increasing prevalence and global dissemination. We identified the occurrence of an MDR Salmonella Infantis clone in broiler flocks in Korea, and the clone was characterized to explore potential genetic causes for its high prevalence and rapid spread in broiler production. In total, 220 Salmonella strains isolated between 2020 and 2023 from broiler flocks were serotyped, and 50 strains were identified as Salmonella Infantis (22.7%). The isolates were tested for antimicrobial susceptibility, and their genetic characteristics were analyzed using pulsed-field gel electrophoresis (PFGE), multilocus sequence typing, and whole genome sequencing (WGS). Forty-six strains of Salmonella Infantis isolated since 2020 were resistant to at least five antimicrobial families including ampicillin, cephalosporins, chloramphenicol, nalidixic acid, and tetracycline. The strains showed 10 PFGE patterns and a single multilocus sequence type 32. Eight representative MDR strains were analyzed by WGS. Seven of the eight strains carried the plasmid of emerging Salmonella Infantis-like megaplasmids recognized globally in emergent MDR Salmonella Infantis. They had a high prevalence of seven antimicrobial resistance genes, six of which were identified in plasmids. Also, they all share virulence genes, including fimbrial adherence determinants and secretion system components, and showed a clonal relationship to strains from North America, South America, and West Asia, suggesting potential international dissemination routes. To mitigate the risks associated with the rapid spread of MDR Salmonella Infantis in poultry production and its potential impact on human health, this study provides valuable insights into implementing effective control measures to reduce Salmonella in broiler production in Korea. Further highlighting the critical importance of enhanced biosecurity and continuous surveillance.

The six major non-O157 serogroups of Shiga toxin-producing Escherichia coli (STEC) are responsible for serious foodborne outbreaks worldwide. This research aimed to detect the six major non-O157 STEC in ground beef, artisanal dairy products, lettuce, spinach, turkey, and chicken sold in northern Morocco. Real-time polymerase chain reaction was utilized to identify the presence of the stx1, stx2, eae, wzx O26, wzx O45, wzx O103, wbdl O111, wzx O121, and ihp1 O145 genes. Out of 310 samples analyzed, Shiga toxin (stx) was detected in 55 enrichments (17.74%), stx, and eae were detected in 54/310 enrichments (17.42%), stx, eae, and genes of at least one of the six serogroups were detected in 34/310 enrichments (10.97%). Among the food matrices analyzed, ground beef showed the highest contamination rate with stx, eae, and O serogroups 13/70 (18.6%), followed by dairy 17/100 (17.00%), turkey 3/40 (7.5%), and chicken 1/40 (2.5%). No O serogroups were detected in lettuce and spinach. The most frequent serogroup was O26 (22/34; 64.7%), followed by O145 (12/34; 35.3%), O45 (12/34; 35.3%), O121 (8/34; 23.5%), O103 (8/34; 23.5%), and O111 (6/34; 17.6%). A set of 32 STEC strains were isolated from nine positive samples (9/34; 26.5%). A high rate of food contamination with STEC may indicate firstly a high public health risk due to this pathogen in beef and dairy products and secondly a lack of compliance with standard hygiene practices. Consequently, it emphasizes the urgent need for rigorous monitoring and intervention measures aimed at mitigating the incidence of STEC contamination.

Listeria monocytogenes (L. monocytogenes) is an important foodborne pathogen. In this study, 41 sporadic listeriosis cases were collected during 2016-2022, including 92.7% of invasive cases and 56.1% of pregnancy-associated cases. The age of cases ranged from 0 days to 88 years, with the majority occurring in individuals aged 20 to <30 years. Serotype 1/2 b was most prevalent among 43 L. monocytogenes isolates, followed by 1/2 a, 4 b, and 3a. Sixteen clonal complexes (CCs) were determined. CC87 occupied the top slot. Genome sequencing-based phylogeny results indicated that Chinese CC1, CC8, and CC87 isolates mostly clustered in clades separating from isolates from other countries. Meanwhile, a few Chinese isolates participated in cocirculating CC1, CC8, and CC87 in Asia, Europe, Africa, South America, North America, and Oceania. All isolates harbored LIPI-1 while LIPI-2 was absent. LIPI-3 and LIPI-4 exhibited an apparent relationship with lineage and CCs. It was notably that CC4, CC224, and CC619 carried both LIPI-3 and LIPI-4. inlB, inlC, inlH, inlK, ipeA, srtA, dltA, lap, ami, fbpA, stp, oatA, intA, prsA2, lgt, hpt, iplA1, bsh, mdrT, mdrM, and brtA existed in all isolates. The percentages of inlA, inlF, inlJ, aut, vip were 97.7%, 97.7%, 97.7%, 83.7%, and 83.7%. A premature stop codon mutation of position 1474(C→T) was detected, resulting in a truncated InlA with 491 aa. High susceptibility to penicillin (100%), ampicillin (100%), gentamicin (100%), erythromycin (100%), daptomycin (100%), meropenem (100%), trimethoprim-sulfamethoxazole (100%), vancomycin (97.7%), tetacycline (97.7%), chloramphenicol (97.7%), and ciprofloxacin (90.7%) was demonstrated. lin and fosX were present in 93.0% of the isolates, respectively. tetM and ermB were also detected. This comprehensive study enriched the understanding of listeriosis cases and diversity of clinical isolates, meanwhile, indicated the spread characteristics of CC1, CC8, and CC87 in China based on phylogeny analysis, providing fundamental data for developing targeting food safety interventions to prevent listeriosis.

Giardia, a flagellated protozoan, is widely distributed in wild rodents. To characterize the presence of Giardia in wild rodents in southern China, this study collected 344 fecal samples from wild rodents in Guangxi, Hunan, and Yunnan provinces. The β-giardin gene (bg) was amplified to identify the presence of Giardia sp. The results showed that 48 samples (13.95%, 48/344) tested positive for Giardia, including three positives for G. duodenalis (assemblage G n = 1, assemblage F n = 2) and 45 positives for G. microti. Among these, Microtus fortis had the highest prevalence at 30.22% (42/139), followed by Apodemus agrarius (7.14%, 3/42). Rattus flavipectus showed a prevalence of 2.56% (1/39), while Bandicota indica had a rate of 5.13% (2/39). The prevalence of Giardia in males (18.27%, 36/197) was slightly higher than in females (8.16%, 12/147). To the best of our knowledge, the present study reported the detection of assemblage F and assemblage G in B. indica for the first time. In addition, G. microti was found exclusively in M. fortis and a few A. agrarius. This study enriches the epidemiological data on Giardia in wild rodents and provides new insights for future research.

Staphylococcus aureus is a foodborne zoonotic pathogen that threatens food safety and public health. However, few people have conducted long-term and systematic studies on S. aureus contamination in food in Yantai City. To investigate the contamination situation of S. aureus in food and improve the ability of early warning and control of foodborne diseases, a total of 2384 samples from 17 categories were collected from 13 monitoring points in Yantai City, from 2010 to 2023. Forty-four samples were positively detected for S. aureus, with a detection rate of 1.85% (44/2384). The detection rate of S. aureus was highest in Zhifu District (4.12%), followed by Penglai District (2.45%), Zhaoyuan District (2.37%), Kaifa District (2.19%), and Longkou District (1.98%). Positive detection rates were higher in frozen rice and flour products at 8.82% (6/68), quick-frozen dishes at 5.56% (1/18), aquatic products at 4.05% (3/74), and meat and meat products at 3.55% (27/760). Positive detection rates in samples from the first, second, third, and fourth quarters were 0% (0/44), 2.21% (20/906), 2.13% (22/1033), and 0.50% (2/401), respectively. Positive detection rates in bulk and prepackaged samples were 2.33% (36/1546) and 0.95% (8/838), respectively, with statistically significant differences (χ² = 5.66, p < 0.05). Positive detection rates were significantly different for samples collected from different sampling stages, of which at production and processing stages was 7.78% (20/257), catering stages 1.38% (10/727), and distribution stages 1% (14/1400) (χ² = 56.41, p < 0.05). Frozen rice and flour products, quick-frozen dishes, aquatic products, and meat and meat products are the main food products contaminated with S. aureus, and the resulting secondary contamination is a hidden danger for the occurrence of foodborne diseases, which should be given sufficient attention.

Staphylococcus aureus (S. aureus) is a major zoonotic pathogen. To investigate CRISPR carriage in S. aureus isolates from cows with mastitis and the role of the CRISPR system and efflux pumps in antibiotic resistance. We analyzed antibiotic resistance genes and CRISPR loci, sequenced spacers, and assessed correlations between CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) presence and antibiotic resistance in 234 S. aureus isolates. The changes in CRISPR sequences were examined by continuous passage of 360 generations without antibiotic pressure. Subsequently, variations in CRISPR loci and transcript levels were measured under ciprofloxacin (CIP) exposure. In addition, an S. aureus-25-mepA was constructed to evaluate changes in antimicrobial sensitivity and mepA transcript levels in both planktonic and biofilm states. Our results revealed a CRISPR loci detection rate of 7.69% among the 234 S. aureus isolates, with significantly lower rates of the antibiotic resistance genes gyrA, grlA, norA, and tet(M) in CRISPR-positive isolates compared to those in CRISPR-negative isolates (p < 0.05). CIP-resistant strains exhibited loss of repeat and spacer sequence in CRISPR loci, and the transcript abundance of these loci gradually decreased under CIP pressures, indicating that CRISPR loci deletion or transcript level downregulation under antibiotic stress may be a potential regulatory mechanism of antibiotic resistance. Correlation analysis linked CIP resistance in both planktonic and biofilm S. aureus to mepA transcript levels and biofilm integrity. Our study provides insight into the mechanism by which S. aureus develops antibiotic resistance via the CRISPR system and the MepA efflux pump, offering a theoretical foundation for monitoring the prevalence and resistance of pathogenic bacteria.

Pork contaminated with bacteria can shorten the shelf life and cause foodborne diseases. Bacterial community analysis of raw pork in sale process can help identify bacteria associated with food quality and safety. In this study, 52 pork samples were collected from various supermarkets and farmers' markets in Qingdao, China. And the bacterial community structures in pork were analyzed by high-throughput sequencing of 16S rDNA. Both the α-diversity and β-diversity of bacterial communities in pork samples from farmers' market were higher than those from supermarkets (ANOSIM test, R² = 0.049, p = 0.016). Proteobacteria (88.8%) was the most dominant phylum, and Photobacterium (44.5%) and Acinetobacter (23.9%) were the top two dominant genera in all pork samples. The abundance of most dominant bacterial genera was higher in pork samples from farmers' markets than those from supermarkets, But Photobacterium (ranking first) was just the opposite (p = 0.003). The bacterial communities in pork hadn't obvious clustering characteristics between the two sale locations, while Photobacterium was considered as the biomarker in pork samples from supermarkets according to LefSe analysis (linear discriminant analysis score >4.0). A strong correlation was observed between some samples (R >0.7) collected from different stalls within the same sampling location, indicating cross-contamination possibility in sale process. The findings may have implications for the quality and safety control of pork, particularly for microbial prevention and control during selling and consumption.

Growing evidence supports the efficacy of antimicrobial peptides against foodborne pathogens, though their antimicrobial spectrum and mechanism can vary depending on their origin. We investigated the antimicrobial spectrum of antimicrobial peptides derived from Lactobacillus paracasei A1, their effects on the survival rate and bactericidal mechanisms against Vibrio parahaemolyticus, and identified the functional short peptides within them. The crude extracts of antimicrobial peptides exhibited antibacterial properties against 13 pathogenic bacteria, showing strong inhibition of V. parahaemolyticus by disrupting the structural integrity of cell membranes. At minimum inhibitory concentrations, these peptides significantly disrupted the initial adhesion, membrane formation, and existing biofilms of V. parahaemolyticus, effectively inhibiting pathogen spread, enhancing the efficacy of antimicrobial agents, and reducing food safety risks. LC-MS/MS identification revealed four effective short peptides, all demonstrating potent bacteriostatic effects against V. parahaemolyticus. Our findings indicate that antimicrobial peptides can effectively destroy bacterial structures as well as the stability and regeneration of biofilms, making them promising candidates for use as food additives to control foodborne pathogens.

This study aimed to explore the ameliorative effect of Millettia speciosa Champ. polysaccharides (MSP) on excessive exercise-induced fatigue (EF) mice. The physicochemical characterization and in vitro antioxidant activities were analyzed. The fatigue-related biochemical indexes were determined, and gut microbiota was analyzed by 16S rDNA sequencing. The results showed that MSP primarily consists of total carbohydrates, uronic acids, and proteins. It was mainly composed of glucose, arabinose, and galactose. Additionally, MSP showed good scavenging effects on free radicals. In the experiment of EF mice, MSP intervention effectively extended the pole-climbing and swimming time, significantly increased the levels of muscle and liver glycogen, blood glucose, adenosine triphosphate, glutathione peroxidase, and superoxide dismutase, while significantly decreased the levels of fatigue-related lactate dehydrogenase, creatine kinase, and urea nitrogen. Furthermore, MSP intervention reduced harmful bacteria (Helicobacter, Anaerotruncus, Erysipelatoclostridium, and Lachnospiraceae_FCS020_group), and enriched the beneficial bacteria (Lactobacillus, Alistipes, Ruminococcaceae, and Roseburia). Therefore, MSP may utilize the gut microbiota as a target to alleviate fatigue caused by excessive exercise.