Foodborne pathogens and disease最新文献

Since 2020, more than 2000 illnesses have been linked to foodborne outbreaks associated with onions. In 2023, the U.S. Food and Drug Administration (FDA), the Centers for Disease Control and Prevention, and state partners investigated a multistate outbreak of Salmonella Thompson infections linked to diced onions grown and processed in California. The outbreak resulted in 80 ill people, 18 hospitalizations, and one death reported in 23 states. FDA conducted a traceback investigation that included three illness clusters comprised of five total ill people from four Long-Term Care Facilities. Three inspections, each accompanied by sampling, were conducted at Processor A, Grower A, and Packing Shed A, respectively. The FDA analyzed 18 samples, six of which yielded Salmonella spp. isolates. Isolates recovered from water, sediment, and piping below irrigation equipment, near the growing environment, matched the outbreak strain. Additional isolates recovered from environmental samples matched eight Salmonella Saintpaul clinical isolates from 2022, four Salmonella Infantis clinical isolates from four states from 2022 to 2023, and two unrelated Salmonella Newport clinical clusters from 2021 to 2023. Laboratory, traceback, and epidemiological evidence indicated onions grown in three specific fields as the source of the outbreak, suggesting that the outbreak strain was present at the farm level, established in the soil, and potentially disseminated through agricultural water. Further processing into diced onions could have also spread and/or amplified the pathogen in the product due to the practices and conditions at the processor. This investigation highlighted the importance of outreach and education to enhance onion industry food safety practices and prevent future outbreaks. It also emphasized the need for focused research on onion industry practices, including growing, harvesting, curing, processing, packing, and holding.

Vibrio fluvialis is an emerging foodborne pathogen associated with severe infections. In this study, immunomagnetic beads (IMBs) were synthesized by conjugating nanobody N71 to magnetic nanoparticles (MNPs) via polyethylenimine (PEI) and glutaraldehyde (GA) cross-linking. Due to the high affinity of N71 for V. fluvialis lipopolysaccharide, the IMBs efficiently and specifically captured the target pathogen. When integrated with ToxR-targeted quantitative real-time PCR, this system achieved enhanced detection sensitivity (48 CFU/mL) and reduced false-positive rates. The optimization results showed that the capture efficiency of V. fluvailis reached its maximum (95%) when 125 µg of N71 were conjugated to 1 mg of MNPs to form the MNPs-PEI-GA-Nbs conjugates, achieved with a conjugate dosage of 0.5 mg and an incubation time of 45 min. Nontarget bacterial interference experiments and actual sample detections validated the excellent specificity of the method for detecting V. fluvialis. Compared with conventional culture-based methods, this method reduced detection time from 24-48 h to <7 h, providing an efficient and reliable alternative for rapid detection of V. fluvialis in food samples.

Cyclospora cayetanensis is a human-specific protozoan parasite that causes gastrointestinal illness, primarily through the ingestion of contaminated water or fresh produce. This study provides an epidemiological overview of cyclosporiasis in Canada from 2000 to 2022 using data from the Canadian Notifiable Disease Surveillance System, FoodNet Canada, and outbreak investigations. A total of 5337 cases were reported during this period, with the incidence increasing from 0.12 to 1.70 per 100,000 population. Seasonal peaks occurred between May and August of each year, and adults aged 30-59 years were disproportionately affected. Enhanced surveillance data identified international travel, particularly to resorts in Mexico, as a common exposure. National-level investigations occurred annually from 2013 to 2022, and various fresh produce items were identified as items of interest, but few investigations led to the identification of a source of illness. Advancements in molecular diagnostics since 2015 have likely contributed to the observed rise in case detection. This report underscores the burden of cyclosporiasis in Canada and highlights the need for continued surveillance, public health interventions targeting contaminated produce, and travel health messaging to mitigate outbreaks and reduce transmission. It also underscores the importance of real-time genetic typing to identify and differentiate clusters of closely related isolates that are more likely to share a common source.

The number of dairy farms in Bangladesh is steadily increasing, yet the characterization of common pathogenic organisms such as Klebsiella aerogenes remains underexplored. Due to the overwhelming challenges of antimicrobial resistance, the transmission of antibiotic resistance genes, and mobile colistin resistance (mcr) genes through zoonotic organisms, this study aimed to characterize K. aerogenes in raw milk in Sylhet. In this study, a total of 234 raw milk samples were collected from different dairy farms and milk-selling points in Sylhet. Then, isolates were detected by 16S rRNA gene through PCR after standard cultural and biochemical tests. Furthermore, antibiotic sensitivity test was performed using the disc diffusion method, followed by screening of antibiotic-resistant genes (TEM, CTX-M, CTX-M-1, CTX-M-2a, SHV, OXA-1, CMY, and NDM-1) and mcr genes (mcr-1 to mcr-9). Finally, partial sequencing of 16S rRNA was performed to study the genetic diversity. Among 234 samples, 86 (36.44%) were positive for Klebsiella and exhibited variation in resistance levels to amoxicillin (100%), ampicillin (100%), ceftazidime (100%), tetracycline (100%) followed by azithromycin (89.54%), cefoxitin (86.04%), gentamicin (83.74%), and cefuroxime (77.90%). All the samples harbored the bla_TEM gene (100%) and showed negative results when screening for mcr genes. The phylogenetic outcome reported that those isolates were closely related to K. aerogenes. According to our findings, the majority of the isolates were resistant to several antibiotics and contained the bla_TEM gene, which may represent a significant risk to the overall well-being of the population. These findings underscore that raw milk could be a potential harbor for multidrug resistance K. aerogenes, raising concerns about antimicrobial resistance transmission through traditionally processed dairy products, as such products are often prepared without proper heat treatment. The study emphasizes the need for strict hygiene practices and mandatory pasteurization measures during processing to reduce potential public health risks.

Staphylococcus aureus is one of the major causes of foodborne diseases and its presence in food products may poses a public health challenge. The aims of this study were to assess in vitro the capacity of S. aureus isolates from foods to form biofilm and to determine their antibiotic susceptibility. A total of 80 S. aureus isolates were characterized. The slime production ability was evaluated by congo-red agar (CRA) and the biofilm formation was carried out by microtiter-plate method (MPM). Resistance of isolates to eight antibiotics was determined using disc diffusion method. Sixty-four (80%) of the isolates were slime producers on congo-red agar. However, all isolates were biofilm producers on microtiter-plate method. The highest resistance profiles were ascribed to penicillin G (91.25%) and tetracycline (41.25%). Twelve isolates were methicillin-resistant (MRSA) harboring the mecA gene. All of these MRSA isolates were negative for the genes of the Panton Valentine leukocidine (lukF/S-PV). Typing of the MRSA isolates indicated that they belonged to three spa-types including t024, t450 and t688. The presence of biofilm producers and multidrug resistant isolates (MRSA) in food samples can represent a risk for public health. Therefore, an efficient control and effective measures were needed along the production chain to ensure the food safety.

Salmonella enterica is one of the most common foodborne pathogens associated with the consumption of contaminated porcine, dairy, and avian products. Nontyphoidal Salmonella is a major cause of bacterial diarrhea, responsible for ∼150 million cases and 60,000 deaths annually. The main goal of this study was to determine the prevalence of Salmonella spp. and to establish the virulence profile (VP) from genes (avrA, invE, ssaD, sseF, ssaQ, ttrC) and plasmid genes (pefA, spvB, spvC) in isolates obtained from cheese, chicken, and pork sold in food markets in Barrancabermeja, Colombia. A survey was conducted on 100 samples each matrix. The detection of Salmonella spp. followed the ISO 6579:2017 standards modified, and isolates were confirmed using the invA gene. In addition, single polymerase chain reaction assays were developed to detect the nine virulence genes. Salmonella spp. was found in 62%, 32%, and 14% of pork, chicken, and cheese samples, respectively. A total of 277 isolates were biochemically, serologically, and molecularly compatible with Salmonella spp. The most representative serogroups were C and B. Forty-seven combinations of virulence gene were detected; 53.5% of the pork isolates, 46.2% of the cheese isolates, and 39% of the chicken isolates were distributed among VP1, VP2, and VP3 suggesting a higher pathogenic potential. In addition, seven isolates harbored plasmid-encoded virulence genes (spvB and spvC), which are associated with increased invasiveness. The results revealed a higher prevalence of Salmonella spp. in pork and chicken compared with other studies conducted in Colombia. The serogroups identified include serovars that more frequently affect humans Salmonella Enteriditis, Salmonella Newport, and Salmonella Typhimurium. The isolations have the majority of the virulence genes studied. These findings highlight the need to improve control measures and educate food handlers to minimize the presence of Salmonella spp. and its potential transmission.

In 2022, the U.S. Food and Drug Administration (FDA), the Centers for Disease Control and Prevention (CDC), and state partners conducted a sample-initiated investigation of a multistate outbreak of Salmonella Senftenberg illnesses linked to peanut butter. Twenty-one illnesses and four hospitalizations were reported in 17 states, with a significant epidemiological signal for peanut butter from Firm A. Whole genome sequence (WGS) data from a Salmonella-positive environmental swab sample collected at Firm A in 2010 yielded the outbreak strain that was a match to the WGS data from the 2022 clinical isolates. Lot code information collected from patients indicated Firm A's facility in Kentucky as a common manufacturing source, and FDA and state partners initiated an inspection. In 2021, Firm A installed two new roasters with at least one of the cooling air supply vents leaking, allowing unfiltered air and rainwater to enter the cooling section after the roasting process. Investigators noted the limitations of Firm A's finished product testing program to identify contamination. Investigative partners from five states collected and analyzed 14 product samples, and FDA collected 205 environmental swabs, and all were negative. Although the exact source and route of the contamination were not determined, epidemiological and traceback evidence confirmed peanut butter consumed by patients was produced by Firm A. Firm A voluntarily recalled all implicated products and provided a plan for corrective actions and restart to FDA. This was the first major domestic investigation of a multistate-foodborne illness outbreak linked to peanut butter since 2012. This investigation demonstrates the importance of caution with reliance on finished product testing, taking appropriate corrective actions when detection occurs, and potential benefits for industry to incorporate WGS as a tool in their environmental monitoring program.

The Burkholderia gladioli pv. cocovenenans (B. cocovenenans) has been linked to fatal food poisoning cases, which could produce the deadly toxin of bongkrekic acid (BA). However, genomic characterization and toxin production pathways of B. cocovenenans strains remain elusive. This study aimed to explore the BA-producing ability associated with the evolution of the bon gene cluster and to analyze the intraspecies genomic diversity and phylogenetic relationships of B. gladioli based on the 17 genomes of B. cocovenenans strains isolated from Shenzhen City, China. Genome sequencing results suggested that the genome sizes of these B. cocovenenans strains were mostly approximately 8 Mb, with a GC content of approximately 68%. The evolutionary tree analysis of the whole-genome sequences showed that significant divergences and distinct cluster were exhibited among these B. cocovenenans strains. Comparative genomic analysis indicated that the genomes of strains 2020051, 2021031, and 2021067 contained the complete and entire bon gene cluster, supporting that these strains displayed obviously BA-producing ability. The genomes of strains 2021028 and 2020041 lacked the entire bon gene cluster. However, the genomes of strains 2021037, 2021024, 2021035, and 2021031 exhibited disruptions in their bon gene clusters. This finding indicated the loss of specific genes within the cluster, suggesting a reduced capability for BA production in these strains. The present results indicated that the bon gene cluster in the genome played a key role in the toxin BA biosynthesis of different B. cocovenenans strains. This study provided a comprehensive understanding of the relationship between genomic diversity and BA production of this lethal foodborne pathovar, which will potentially contribute to the risk identification and food poisoning outbreak prevention of B. cocovenenans.

Focusing on the global epidemiology and subtype distribution of Blastocystis sp. in camelids (camels and alpacas), the present systematic review and meta-analysis was conducted. Utilizing relevant keywords, a thorough search was conducted on four electronic databases (PubMed, Scopus, Google Scholar, and Web of Science) with no time constraints up to April 1, 2024. Total estimates and 95% confidence intervals (CIs) were subsequently calculated using a random-effects model. Finally, 11 studies with 18 datasets provided the required data. The global prevalence of Blastocystis sp. in camelids was estimated at 22%, with a 95% CI of 17.2-27.6%. Among 1061 camels, the pooled prevalence of Blastocystis sp. was 21.6% (95% CI: 16.6-27.6%) across 5 countries, which was lower than the 23.5% (95% CI: 12.2-43.1%) found in 449 tested alpacas across 3 countries. Camels were found to carry 15 genetically diverse subtypes (STs) of Blastocystis sp. (ST1-ST7, ST10, ST14, ST15, ST21, ST24, ST25, ST26, and ST30). Among these, ST10 exhibited the highest pooled prevalence [five datasets, 38.3% (95% CI: 22.4-57.1%)], followed by ST1 [three datasets, 24% (95% CI: 6-61.2%)] and ST14 [four datasets, 15.2% (95% CI: 6.7-31%)]. Alpacas exhibited three distinct STs (ST5, ST10, and ST14). Among these, ST10 [four datasets, 50.3% (95% CI: 33.3-67.3%)] had the greatest weighted frequency, with ST14 [four datasets, 40.2% (95% CI: 23.8-59.1%)] following closely behind. Of note, 9 zoonotic STs (ST1-ST7, ST10, and ST14) have been identified in camels and 3 in alpacas (ST5, ST10, and ST14) out of the 16 zoonotic STs (ST1-ST10, ST12, ST14, ST16, ST23, ST35, and ST41) of Blastocystis sp. reported to date. Overall, camelids (camels and alpacas) can serve as a diverse reservoir for various Blastocystis sp. STs, potentially contributing to infections in humans, animals, and water sources. Nevertheless, research in this area is somewhat restricted, necessitating careful interpretation of the findings.

Aspergillus fumigatus is a foodborne mycete that can induce recurrent pneumonia, but the current detection methods have insufficient sensitivity and rapidity. Here, we aim to develop an efficient and sensitive loop-mediated isothermal amplification (LAMP) primer set for A. fumigatus detection. First, we designed a novel set of LAMP primers by targeting the Beta-tubulin (β-tub) gene. The LAMP reaction system was optimized by screening reaction temperature and betaine concentration. And then, the specificity of the proposed primers was verified by using 10 interferent microorganism species. The sensitivity of the designed method was compared with that of polymerase chain reaction (PCR) on pure cultures and complex matrix. The accuracy and response time of the method were examined by simulated samples. Our proposed primer set could accurately detect A. fumigatus from different food matrices with no response to other microorganisms. More intriguingly, this method possessed a low limit of detection (2 copies/reaction, 10-fold less than PCR), a short measuring time (<30 min), and a naked-eye readability. A real sample test demonstrates the good recovery rate and accuracy in apple, corn, milk, and other food matrix. Our proposed β-tub primer set provides great potential for rapid assessment of A. fumigatus contamination in food by integrating portable equipment and microscale reaction system. [Figure: see text].