Foodborne pathogens and disease最新文献

In recent years, there has been a significant increase in infections caused by carbapenemase-producing strains, with carbapenem-resistant Pseudomonas aeruginosa (CRPA) emerging as a priority pathogen according to the World Health Organization. This study aimed to evaluate the molecular epidemiology of CRPA isolated from patients referred to Children's Medical Center in Tehran, Iran. P. aeruginosa isolates collected from different children's wards were screened for common carbapenem-resistant genes by polymerase chain reaction (PCR). Genetic relatedness between isolates was assessed by pulsed-field gel electrophoresis (PFGE). The study included 133 participants, with 50% being male, and revealed a median age of 2 years (interquartile range: 6 months to 6 years). Carbapenem resistance was detected in 15% of cases (n = 20), with CRPA isolates predominantly found in the emergency ward (60%). The median age of patients with CRPA was significantly higher than those with carbapenem-susceptible P. aeruginosa (6 years vs. 1 year). PCR analysis revealed metallo-β-lactamase production in 45% of CRPA isolates (n = 9), with bla_NDM being the most prevalent gene. PFGE analysis of the CRPA isolates identified three clusters (Cluster I, II, and III). Cluster I, comprising 65% of all isolates (n = 13), was predominantly found in the emergency ward. Notably, bla_NDM-producing strains were prevalent in the emergency ward. Our study highlights the significant prevalence of CRPA in the emergency ward of our hospital and underscores the importance of targeted surveillance and infection control measures to curb its spread within health care settings.

Salmonella is a globally prevalent foodborne bacterium, and ceftriaxone and azithromycin have been regarded as drugs of choice for treating Salmonella infections, particularly in children. With the growing incidence of ceftriaxone and azithromycin resistance in Salmonella, there is an urgent requirement for a rapid and dependable gene testing approach to enhance the efficacy of treating Salmonella infections. Utilizing the orange to green visible dye approach, this study developed loop-mediated isothermal amplification (LAMP) assays for the sensitive and specific detection of Salmonella, ceftriaxone and azithromycin resistance genes (including CTX-M-1 group, mph(A), and ermB genes) in stool and blood samples. The specificity and sensitivity of primers during the LAMP assays for detection of Salmonella, CTX-M-1 group, mph(A), and ermB genes were determined in this study. The detection threshold for Salmonella was found to be 1.5 × 10³ colony-forming units (CFU)/mL, while it was 1.5 × 10² CFU/mL for CTX-M-1 group genes (including bla_CTX-M-3, bla_CTX-M-15, and bla_CTX-M-55), 1.5 × 10² CFU/mL for mph(A), and 1.5 × 10² CFU/mL for ermB, showing 10-10³-fold, 10³-fold, and 10⁵-fold increased sensitivity compared with the polymerase chain reaction assay, respectively. Results indicated that the LAMP primers designed for Salmonella, CTX-M-1 group, mph(A), and ermB genes possess high specificity (100%) and sensitivity (over 94%). This novel approach advocates its application in detecting Salmonella, CTX-M-1 group, mph(A), and ermB genes.

Staphylococcus aureus and a few species of coagulase negative are frequently associated with food poisoning. Raw milk and dairy products are among the foods usually associated with outbreaks due to staphylococcal intoxication. This study aimed to determine phenotypic and genotypic antimicrobial resistance profiles to beta-lactam drugs in Staphylococcus coagulase positive (CoPS) and negative (CoNS) isolates. A total of 58 CoPS and 45 CoNS isolates recovered from raw milk and artisanal cheese from Santa Catarina were analyzed. All isolates (n = 103) were subjected to antimicrobial susceptibility testing. High levels of resistance to penicillin (41% of CoPS and 31% of CoNS), amoxicillin (40% CoPS), ampicillin (36% CoPS), and sulfamethoxazole-trimethoprim (35% CoNS) were observed. Twenty six percent of the isolates (18 CoPS and 9 CoNS) exhibited multiresistance profile; which means, they were resistant to at least three different classes of the antimicrobial drugs. Detection of resistance genes (mecA, mecC, and blaZ) was performed using multiplex polymerase chain reaction. Twelve isolates (9 CoPS and 3 CoNS) were positive for mecA, whereas 10 strains (4 CoPS and 6 CoNS) were positive for blaZ. The detection of resistant and multidrug resistant isolates emphasizes the necessity to develop strategies to better comply with good manufacturing practices and health care guidelines.

This study aimed at evaluating the occurrence, antibiotic resistance, and β-lactamase production in Staphylococcus isolates recovered from meat and meat products, as well as the incidence of antimicrobial resistance (AMR) genes in these bacterial isolates. The prevalence of Staphylococcus was very high (75% and 50%) in street kebab and raw buffalo meat, respectively. The antibiotic resistance and susceptibility behavior showed that 82% of the Staphylococcus isolates were resistant to β-lactam antibiotics such as aztreonam, followed by methicillin (68%), oxacillin (54%), cefepime (36%), ceftazidime (34%), cefaclor (24%), cefotaxime (22%), ertapenem (4%), meropenem and imipenem (2%). Among non-β-lactam antibiotics, the most widespread resistance was observed against nalidixic acid (80%), sulfadiazine (76%), vancomycin (24%), erythromycin (10%), chloramphenicol (6%), and kanamycin and gatifloxacin (4%). One hundred percent of the isolates were susceptible to ciprofloxacin, tetracycline, gemifloxacin, and cefotaxime/clavulanic acid. In vitro drug-resistant characteristics revealed 36 distinct resistance patterns of Staphylococcus isolates, with 82% of them being multidrug resistant (MDR). Iodometric assay showed that 48% of the Staphylococcus isolates produced β-lactamase and 24% of the isolates were capable of producing extended-spectrum beta-lactamases phenotypically. The most commonly detected AMR gene was mecA (29.2%), followed by Sul 1 (25%) and qnrS and qnrB (20.8%), in Staphylococcus isolates. Current findings show widespread occurrence of MDR Staphylococcus strains in raw meat and street meat products, which is a potential risk to public health. Therefore, the study suggests strict monitoring of hygiene through the whole food chain and judicious use of antibiotics.

Twenty-one environmental Vibrio vulnificus strains from the Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE) bacteria collection, 20 of them isolated from oyster samples and 1 from a reported clinical case, were sequenced to analyze the genomic divergence between 2 genotypes, E-genotype and C-genotype, proposed by various groups to distinguish clinical (C) from environmental (E) V. vulnificus strains. As indicated in previous analyses of PFGE, MLST, and rtxA, 9 of the CICESE isolates were identified as vcgE, compared with 12 as vcgC. Separation of the genotypes into these 2 groups was confirmed in this study, based on the presence of certain genes in the 21 genomes, the presence of virulence factors, and rtxA sequencing. Most genomes from oyster isolates expressed rtxA-C type, with the exception being rtxA-M type detected in CICESE-594 a vcgE strain isolated from a clinical case. Although several genetic approaches clearly indicate differences between the C- and E-genotypes, none of them, including those in this study, can highlight a single factor that could be used to indicate the potential pathogenicity of V. vulnificus isolated from oysters.

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.

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.

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.

Shiga toxin-producing Escherichia coli (STEC) is a significant pathogen that can cause foodborne illnesses and pose a serious public health problem. To date, no systematic evaluation or meta-analysis of STEC carriage in Chinese cattle has been conducted. Therefore, we conducted a systematic review and meta-analysis to assess the prevalence of STEC in cattle in China over the past decade. We retrieved 1868 articles from 6 databases (PubMed, Web of Science, CNKI, Wanfang, VIP, and Baidu). Based on criteria such as sample source, isolation time, and species, we selected 39 studies (comprising 16,437 samples from 14 provinces) for systematic review and meta-analysis. The analysis results indicated that the pooled prevalence of E. coli in cattle during the selected time period was 6% (95% CI: 0.03-0.09). Subgroup analysis revealed variations in STEC positivity rates across different sectors. The highest positivity rate was observed in the slaughter and processing sector (12%, 95% CI: 0.03-0.17), followed by the retail sector (6%, 95% CI: 0.01-0.13), with the breeding sector showing the lowest rate (5%, 95% CI: 0.03-0.17). Among the regions studied, Shandong exhibited the highest pooled prevalence (15%, 95% CI: 0.01-0.30), followed by Hebei (12%, 95% CI: 0.00-0.30) and Hubei (11%, 95% CI: 0.03-0.09). These findings indicate an uneven distribution of STEC in cattle across China. Our systematic evaluation of data over the past decade provides insights into the prevalence of STEC in cattle in China. These findings may assist in the prevention and control of STEC in cattle in the country. We recommend conducting further epidemiological investigations and establishing comprehensive surveillance programs to identify risk factors associated with STEC in cattle, thereby enhancing prevention and control strategies.