Molecular characteristics of Shiga toxin-producing Escherichia coli in a dairy farm and market-sold raw livestock meats in Suzhou City
10.19485/j.cnki.issn2096-5087.2022.10.012
- Author:
Feifei HUANG
;
Bo WANG
;
Ning ZHANG
;
Xiaolong WANG
;
Wenyan ZOU
- Publication Type:Journal Article
- Keywords:
Shiga toxin-producing Escherichia coli；virulence gene；drug resistance；pulsed-field gel electrophoresis
- From:
Journal of Preventive Medicine
2022;34(10):1031-1037
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the prevalence and molecular characteristics of Shiga toxin-producing Escherichia coli (STEC) in a large dairy farm and market-sold raw livestock meats in Suzhou City, so as to provide the evidence for evaluating human health risks of STEC.
Methods:Bovine stool samples and breeding environmental samples were collected from a large dairy farm in Suzhou City, and beef, pork and mutton samples were collected from markets in Suzhou City. STEC strains were isolated and virulence genes were characterized in STEC strains using quantitative fluorescence PCR assay. The sensitivity to common antibiotics was tested using the broth microdilution plate method, and the genotypes of STEC were characterized using pulsed-field gel electrophoresis (PFGE).
Results: A total of 624 samples were collected, including 110 adult cow stool samples, 170 calf stool samples, 60 farm environmental samples, 126 beef samples, 100 minced beef samples, 15 pork samples, 15 minced pork samples, 18 mutton samples and 10 ground mutton samples. A total of 12 non-O157 STEC strains were isolated, with a detection rate of 1.92%, and the detection rates of non-O157 STEC strains were 4.12%, 1.59% and 3.00% in calf stool samples, beef samples and minced beef samples, respectively, while non-O157 STEC strains were not detected in adult cow stool samples, environmental samples, pork samples, minced pork samples, mutton samples, or minced mutton samples. Among the 12 STEC strains, there were 4 strains carrying stx1 gene, 4 strains carrying stx2 gene and 4 strains carrying stx1 and stx2 genes. The 12 STEC strains showed the highest prevalence of resistance to ampicillin, ampicillin/sulbactam, cefotaxime and cefazoline (all were 41.67%), and were sensitive to imithiomycin, polymyxin, azithromycin, cefoxitin and ciprofloxacin, and there were 5 strains with multidrug resistance (41.67%). The 12 STEC strains were characterized with 11 genotypes and had no unique gene fingerprint patterns, with the Dice similarity coefficient ranging from 61.3% to 92.7%.
Conclusions:The detection of non-O157 STEC strains is high in calf stools, and non-O157 STEC strains show a level of resistance to common antibiotics and present molecular polymorphisms. The monitoring and management of STEC strains should be strengthened.
- Full text:苏州市某奶牛养殖场及市售生畜肉产志贺毒素大肠埃希菌分子流行病学分析.pdf
