During our surveillance period, we found a new type of Vibrio parahaemolyticus (V. parahaemolyticus) with serotype O10:K4, which had increased over the past 2 years in Huzhou and became the second most common serotype after O3:K6. Strains were isolated from stool samples of diarrhea patients in the First People's Hospital in Huzhou. The serotypes, virulence-associated genes, antimicrobial susceptibility, and pulsed field gel electrophoresis (PFGE) of these strains were analyzed. Between January 2017 and December 2021, there were 598 (5.36%) V. parahaemolyticus-positive samples of 11,166 stool specimens. The V. parahaemolyticus detection rate was high in summer months. The O3:K6 was the dominant serotype in 2017-2020 and a new serotype, O10:K4, was the predominant serotype in 2021. The majority of isolates tested were resistant to ampicillin (86.8%). We randomly chose the strains with serotype O3:K6 and O10:K4 for PFGE to compare the genetic relationship between these two serotypes. The results showed that the PFGE profiles of V. parahaemolyticus O3:K6 and O10:K4 were genetically similar. The strains showed a tendency to cluster on the basis of their serotype profiles. However, some O3:K6 strains showed 100% similarity with O10:K4 strains. A new serotype with pandemic potential of V. parahaemolyticus, O10:K4, was detected in 2020 and became dominant in 2021 in Huzhou.
Meat adulteration has recently become an issue of increasing public concern. In addition to posing a health risk to consumers with metabolic disorders or allergies, meat adulteration has triggered many economic and religious problems. Chicken meat is one of the eligible candidates for meat adulteration due to its low cost and ready availability.This study developed a loop-mediated isothermal amplification (LAMP) assay coupled with a lateral flow dipstick (LFD) to identify chicken in non-chicken products. , we optimized the amplification time and temperature to obtain the best result . This method is performed at a constant temperature in a water bath and complete in 1 hour. No precision instruments or equipment are needed. With a one-step reaction and easy operation, the testing cost is low. Whith high sensitive and specific, this method provide a valuable method for identifying chicken in non-chicken products. which meets the requirements of on-site inspection and detection.
Background: Human metapneumovirus (hMPV) is one of the important pathogens in infant respiratory tract infection. However, the molecular epidemiology of hMPV among children < 14 years of age hospitalized with severe acute respiratory infection (SARI) is unclear. We investigated the hMPV infection status and genotypes of children hospitalized with SARI from January 2016 to December 2020 in Huzhou, China. Methods: A nasopharyngeal flocked swab, nasal wash, or nasopharyngeal swab/or opharyngeal swab combination sample was collected from children with SARI in Huzhou from January 2016 to December 2020. Quantitative reverse transcription-polymerase chain reaction was performed to detect hMPV RNA. The hMPV F gene was amplified and sequenced, followed by analysis using MEGA software (ver. 7.0). Epidemiological data were analyzed using Microsoft Excel 2010 and SPSS (ver. 22.0) software. Results: A total of 1133 children with SARI were recruited from 2016 to 2020. Among them, 56 (4.94%) were positive for hMPV-RNA. Children < 5 years of age accounted for 85.71% of the positive cases. The hMPV incidence was high in spring and winter, especially in December and January to March. Phylogenetic analysis of the F-gene sequences of 28 hMPV strains showed that the A1, B1, and B2 genotypes were prevalent in Huzhou, and the dominant hMPV genotype varied according to surveillance year. Conclusions: HMPV is an important respiratory pathogen in children in Huzhou, with a high incidence in winter and spring in children < 5 years of age. In this study, genotypes A1, B1, and B2 were the most prevalent.
Vibrio parahaemolyticus is responsible for seafood-borne gastroenteritis worldwide. Isolates of V. parahaemolyticus from clinical samples (n = 54) and environmental samples (n = 38) in Huzhou were analyzed by serological typing, virulence gene detection, antibiotic resistance testing, and pulsed-field gel electrophoresis (PFGE) for molecular typing. O3:K6 was the main serotype and tlh+tdh+trh- was the most frequently detected virulence genotype in clinical strains. O2:Kut was the main serotype and tlh+tdh-trh- was the most frequently detected virulence genotype in environmental strains. Antibiotic resistance testing indicated that the isolates were highly resistant to ampicillin (90.76%), followed by gentamicin and tetracycline. Following the restriction enzyme NotI digestion, the 91 strains yielded 81 PFGE patterns, and 16 clones had similarity values of > 85.00%, indicating a high level of diversity. Finally, there may be cross-contamination between freshwater and seawater products, so it is necessary to strengthen supervision of food processing.
Vibrio parahaemolyticus is a marine seafood-borne pathogen that causes gastrointestinal disorders in humans. In this study, we developed a cross-priming amplification (CPA) assay coupled with vertical flow (VF) visualization for rapid and sensitive detection of V. parahaemolyticus. This assay correctly detected all target strains (n = 13) and none of the non-target strains (n = 27). Small concentrations of V. parahaemolyticus (1.8 CFU/mL for pure cultures and 18 CFU/g for reconstituted samples) were detected within 1 h. CPA-VF can be applied at a large scale and can be used to detect V. parahaemolyticus strains rapidly in seafood and environmental samples, being especially useful in the field.
Salmonella enteritidis is a main pathogen responsible for sporadic outbreaks of gastroenteritis, and therefore is an important public health problem. This study investigated the drug resistance and genomic characteristics of S. enteritidis isolated from clinical and food sources in Huzhou, Zhejiang Province, China, from February 1, 2021, to December 30, 2023. In total, 43 S. enteritidis strains isolated during the study period were subjected to virulence gene, drug resistance gene, genetic correlation, antibiotic resistance, and multilocus sequence typing analyses. All 43 isolates were identified as ST11, and contained 108 virulence-related genes. Drug sensitivity analysis of the 43 isolates showed resistance rates of 100% to nalidixic acid and 90.70% to ampicillin and ampicillin/sulbactam. Multidrug resistance is a serious issue, with 81.40% of strains resistant to three or more antibacterial drugs. Genome sequencing indicated that S. enteritidis possessed 23 drug resistance genes, of which 14 were common to all 43 isolates. Phylogenetic analysis based on core genome single-nucleotide polymorphisms divided the 43 S. enteritidis strains into three clusters, with the 10 samples from an outbreak forming an independent branch located in cluster 3.