Foodborne pathogens and disease最新文献

Probiotics are critical for resisting the colonization of foodborne pathogens in gut. Lactiplantibacillus plantarum ZDY2013 has been proven to have multiple biological activities, including antagonizing pathogens. In this study, we systematically evaluated the protective effects of live and heat-killed L. plantarum ZDY2013 on Salmonella enterica serotype Typhimurium infection and investigated the potential mechanisms using mice infection model, HT-29 epithelial cell model, and RAW264.7 macrophage model. The results showed that live and heat-killed L. plantarum ZDY2013 could effectively reduce the Salmonella load in mice, improve the intestinal barrier by upregulating the expression of tight junction proteins (Zonula occludens protein 1 and Claudin-1) and the number of goblet cells, and alleviate the inflammation by decreasing the level of proinflammatory cytokines (interleukin-1β, tumor necrosis factor-α, interferon gamma and IL-6). In addition, L. plantarum ZDY2013 could significantly reduce the adhesion and invasion of S. Typhimurium to HT-29 epithelial cells, activate macrophages and enhance its bactericidal ability. These results indicated that live and heat-killed L. plantarum ZDY2013 has the potential to be developed as a functional health food against S. Typhimurium infection.

Sarcocystis fayeri is a foodborne, pathogenic protozoan. As the enterotoxicity of S. fayeri to the host has been reported to be inactivated by low-temperature treatment due to loss of viability, regulations on horse meat stipulate that it is to be frozen before distribution in Japan. However, inactivation of S. fayeri enterotoxicity by freezing horse meat has not yet been verified in vivo. We analyzed the effect of low-temperature treatment on the enterotoxicity of S. fayeri in rabbit intestinal loop tests using the treated S. fayeri bradyzoites. The viability of S. fayeri decreased with lower treatment temperature and longer treatment time. The bradyzoites treated at 4°C developed fluid retention in the rabbit ileal loop, while those treated at -20°C and -80°C did not. This study suggests that the enterotoxicity of S. fayeri may be caused by factors or mechanisms that are inhibited at temperatures lower than -20°C.

Food safety is a critical issue in the 21st century due to antibiotic-resistant bacteria causing harmful foodborne diseases. This comprehensive study meticulously examined the presence of bacterial isolates, quinolone residue, and antimicrobial resistance genes in samples of broiler and fish meat. Forty samples were collected from various locations in the Faisalabad metropolis. The samples underwent culture on various types of agar, and the Vitek 2 compact system was used to confirm the isolates along with determining the minimum inhibitory concentration of antibiotics. Additionally, polymerase chain reaction was used to identify antimicrobial-resistant genes, and an enzyme-linked immunosorbent assay (ELISA) kit was employed to detect quinolone residue in each sample. Out of 40 fish samples, 66 polymicrobials were identified with Escherichia coli being the most prevalent (26.6%), followed by Klebsiella pneumoniae (16.6%) and Acinetobacter baumannii (15%). Furthermore, 70 polymicrobial were identified in the broiler samples, with 41.6% E. coli and 15% K. pneumoniae. In fish isolates, 14 (21%) qnr gene, 18 (27.2%) bla_CTX-M, and 11 (16.6%) bla_NDM-1, and in broiler samples, 19 (27.1%) qnr gene, 19 (27.1%) bla_TEM and 22 (31.4%) bla_CTX-M, and 5 (7.1%) bla_NDM-1 were found. Eighteen (45%) broiler and 7 (17.5%) fish samples with more than 100 µg per kg (ppb) for quinolone residues. The study concluded that the increased prevalence of multidrug-resistant bacteria and quinolone residue poses a significant threat to consumer health.

Antimicrobial-resistant bacterial contamination of meat poses a significant global public health risk. We aimed to determine antimicrobial resistance profiles and trends of Escherichia coli recovered from carcasses of healthy food-producing animals in South Korea during 2010-2023. In total, 4748 E. coli isolates obtained from cattle (n = 1582), pigs (n = 1572), and chickens (n = 1594) were assessed for susceptibility to 12 antimicrobials. Antimicrobial resistance was different among samples. Overall, antimicrobial resistance was high in pigs and chicken carcasses. More than about 80% of isolates from pigs and chickens exhibited resistance to one or more antimicrobials. Among the tested antimicrobials, resistance to ampicillin, chloramphenicol, streptomycin, and tetracycline was significantly higher in pigs and chickens compared with cattle (p < 0.05). Moreover, chicken isolates showed much higher resistance to nalidixic acid and ciprofloxacin than other samples. Resistance to critically important antimicrobials, colistin, remained less than about 1%, while resistance to ceftiofur showed increased trends in pig and chicken samples. Higher multidrug-resistant (MDR) isolates were identified in chickens and pigs compared with cattle (p < 0.05). Furthermore, most MDR patterns include streptomycin and tetracycline resistance. MDR E. coli contaminating meat during slaughter can be transmitted to humans via the food chain. Thus, prudent use of antimicrobials and proper hygienic practices are urgently needed to reduce the risk of transmission.

This investigation aimed to examine the virulence genes and antimicrobial resistance profiles of Shiga toxin-producing Escherichia coli (STEC) strains found in diarrheal calves in Xinjiang between 2016 and 2022. A total of 800 samples, including 232 fecal and 568 rectal swabs from calves under 2 months old with diarrhea, were analyzed for Shiga toxin (Stx)-encoding genes using polymerase chain reaction. The study characterized the isolates based on their stx subtypes, virulence genes, O serogroups, phylogenetic groups, hemolytic phenotypes, antibiotic resistance, and resistance genes. This investigation detected 32 STEC isolates, with stx1 and stx2 genes in 37.5% and 12.5% of the isolates, respectively. Additionally, half of the isolates contained both genes. The combination of stx subtypes was predominantly observed as follows: stx1a/stx2d (31.3%), stx1a only (31.3%), stx1a/stx2a/stx2d (12.5%), stx2d only (9.4%), stx1a/stx1d/stx2d (6.2%), stx1a/stx1d (6.2%), and stx2a/stx2d (3.1%). The eae gene was found in one isolate that carried stx1, stx2, and hlyA, defining it as enterohemorrhagic E. coli. Additionally, six STEC carrying the astA gene were identified as EAST1⁺ STEC. These isolates did not correspond to the serotypes in the "top seven" category. The phylogenetic analysis revealed that most strains belonged to groups B1 (43.8%) and A (40.6%), with 56.3% exhibiting hemolytic activity. Moreover, among the 34.4% resistant isolates (2021∼2022), the drug resistance rates of STEC isolates to tetracycline, florfenicol, ceftazidime, ampicillin, cefotaxime, gentamicin, and sulphamethoxazole ranged from 21.9% to 34.4%, to streptomycin, piperacillin, ceftazidime, aztreonam-polymyxin B, and cefepime ranged from 3.1% to 18.8%. All isolates exhibited multiple drug resistance. The most common resistance genes identified were floR (31.3%), tetA (25.0%), sulR (15.6%), strA and strB (12.5%), and bla_CTX-M-1, bla_TEM-1, and mph(A) (9.4%). These findings offer valuable information that might aid in developing preventative measures and enhance the comprehension of the epidemiological characteristics of STEC in calves.

Foodborne pathogens have always been of public health concern and represent safety issues for food processors. These pathogens develop new ways to overcome antibiotics, survive in different environmental conditions, and the ability to reproduce in many hostile environments configure them as serious health hazards. Considering the huge number of microorganisms, three bacterial representatives were selected to provide a better knowledge about the question of which one is the worst enemy for humans, from the food industry point of view, taking into consideration their multiplication specificity, virulence, and resistance. As we constantly are exposed to these pathogens in our nutritional habits, this overview aims to summarize the most relevant characteristics associated with the pathogenicity, clinical symptoms and most importantly, how deadly Listeria monocytogenes, Salmonella spp., and Staphylococcus aureus can be in the hospital and the food industry, by comparing among them. Overall, the microbiological knowledge clearly suggests that while all three pathogens are dangerous, L. monocytogenes presents the highest risk of death due to their ability to cause severe complications in vulnerable populations as it presents a range of virulence factors that facilitate evasion of the immune system and cytological effects. Additionally, it shows great resistance to standard food processing and preservation techniques, making it one of the most difficult pathogens to control. Understanding the risks and characteristics of these foodborne pathogens is essential for implementing effective control measures to prevent their occurrence in food products and to promote public health.

This study evaluated the efficacy of nanoemulsified benzyl isothiocyanate (NBIT) and carvacrol (NCR) to reduce Salmonella contamination on alfalfa seeds and sprouts. Given the susceptibility of sprouts to microbial contamination during germination, improved interventions were needed to enhance food safety without compromising product quality. NBIT and NCR were applied to Salmonella-inoculated seeds at high (6.3 log CFU/g) and low (2.4 log CFU/g) inoculum levels and their impact on Salmonella populations, seed germination, sprout quality (length and weight), and visual appearance was assessed. Results revealed that both NBIT and NCR significantly reduced Salmonella populations and most treatments did not adversely affect seed germination or sprout quality. Treatment with 2.0% NBIT achieved reductions of up to 2.4 log CFU/g on seeds and 6.4 log CFU/g on sprouts after 4 days at the low inoculum level. However, treatment with 2.0% NBIT resulted in an 18.8% reduction in germination that occurred at the high inoculum level and a 10.7% reduction at the low inoculum level, along with a slight decrease in sprout size. In contrast, treatments with 0.5% and 1.0% NBIT, as well as 2.0% NCR, reduced Salmonella on seeds by 1.5-2.0 log CFU/g, regardless of inoculum level, and achieved reductions of 5.0-6.4 log CFU/g on sprouts at the low inoculum level. In addition, NBIT (0.5% and 1.0%) and NCR (2.0%) preserved seed germination rates and sprout quality metrics, including length, weight, and visual appearance, comparable with untreated controls. These findings highlight the potential of NBIT and NCR as effective antimicrobial agents for improving the microbial safety of alfalfa sprouts without compromising quality.

The Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and state health and regulatory partners have investigated outbreaks of Salmonella enterica serovar Newport and Typhimurium infections in 2012, 2020, 2022, and 2023 linked to cantaloupes and/or watermelons from Southwest Indiana. In 2023, an outbreak of Salmonella Newport infections included 11 ill people and five hospitalizations reported in six states. The FDA and CDC collaborated with state partners to investigate the outbreak. The traceback investigation did not identify a single point of convergence for cantaloupe or watermelon. Products and environmental samples collected by the FDA and state partners from farms, public land, distributors, and points of service yielded isolates of multiple Salmonella serovars, including Salmonella Typhimurium and Salmonella Newport, that matched by whole genome sequencing to the 2020, 2022, and 2023 outbreak strains. Due to limitations with the traceback investigation and lack of convergence, a specific type of melon or source of contamination was not identified. However, the laboratory findings and historical outbreak information provided additional evidence to support a finding of ongoing contamination issues for cantaloupes and watermelons grown in Southwest Indiana. This is the fourth outbreak of salmonellosis confirmed to be linked to cantaloupes and/or watermelons from this area since 2012. These outbreaks of reoccurring and persisting strains of Salmonella illustrate the urgent need to determine the source, pathway, and extent of environmental contamination in the melon-growing region of Southwest Indiana and for outreach and education to help promote practices to reduce the contamination of melons.

Foodborne disease and its sequelae exert a significant cost on Australia through health care costs, lost productivity, and occasional fatal illness. While estimating the cost of illness for all foodborne pathogens or for specific pathogens has value in quantifying this disease burden, it is also informative to estimate costs by food commodity and to identify priority areas for improving food safety. We combined a cost of illness model for foodborne illness in Australia with an expert elicitation of the food commodities associated with illness for key pathogens. The total cost of the six modeled pathogens was 721 million (June 2023 AUD), with campylobacteriosis having the greatest overall cost (AUD 420 million). Across food categories, AUD 328 million was attributed to poultry, AUD 107 million to vegetables, while dairy, beef, and pork each had costs over AUD 55 million. Strong associations were found between Campylobacter and poultry (69% of campylobacteriosis cases attributed to poultry) and Yersinia and pork (54% of yersiniosis cases attributed to pork). This study highlights poultry as a key cause of foodborne illness in Australia, responsible for almost half of the total costs due to Campylobacter, non-typhoidal Salmonella, Yersinia enterocolitica, Listeria monocytogenes, and Shiga-toxin producing Escherichia coli.

Listeria (L.) monocytogenes is an environmental pathogen that can contaminate a wide variety of food products, leading to foodborne listeriosis outbreaks. In this context, ready-to-eat (RTE) foods of animal and plant origin are of particular relevance as the source of infection. In Germany, the official food and veterinary control laboratories, under the sovereignty of the federal states, examine foodstuffs for the presence of foodborne pathogens, including Listeria. The German National Reference Laboratory for L. monocytogenes regularly organizes inter-laboratory proficiency tests (PTs) to monitor the accuracy and comparability of analyses performed by these official control laboratories. In our study, we provide summary data on frequently contaminated RTE food products in the European Union and present the outcome of five consecutive PTs. RTE food matrices provided by the German National Reference Laboratory for L. monocytogenes included processed meat, fish, vegetable, and dairy products. Overall, the official control laboratories achieved excellent results in the PTs. In total, 91 participants were documented. Flawless results were reported in 93.4% of the cases. Only four times, participants did not pass the PT in the first attempt. By performing official food and veterinary controls along the food chain, control laboratories make a significant contribution to food safety. To keep the excellent standard of the official control laboratories in Germany in line with future challenges in food safety, PTs with relevant RTE food matrices are indispensable.