温州市畜肉中小肠结肠炎耶尔森菌的污染现状与病原特征分析

Analysis of contamination status and pathogenic characteristics of Yersinia enterocolitica in livestock meat in Wenzhou City

目的 了解2020年—2021年温州市畜肉中小肠结肠炎耶尔森菌的污染现状及病原特征。方法 对2020年—2021年温州市食品安全风险监测中的畜肉样本进行小肠结肠炎耶尔森菌的分离鉴定、血清分型、生物分型、毒力基因检测、耐药性分析和脉冲场凝胶电泳(PFGE)分子分型。结果 356份样本共检出小肠结肠炎耶尔森菌31株,检出率为8.71%。分离菌株血清型以O:5型为主,生物型以1A型为主。检出1株4/O:3型菌株携带毒力基因ail、ystA、yadA、virF,其余菌型菌株仅携带ystB或不携带任何毒力基因。分离株对头孢西丁、磺胺异恶唑耐药率最高,为32.26%,多重耐药株有4株,占12.90%。31株分离株经PFGE分型,共获得31种带型。结论 小肠结肠炎耶尔森菌是温州市畜肉中的潜在污染源,菌株耐药率处于较低水平但存在多重耐药株,PFGE带型呈多态性分布。

Objective This paper aims to investigate the contamination status and pathogenic characteristics of Yersinia enterocolitica in livestock meat in Wenzhou City from 2020 to 2021. Methods Yersinia enterocolitica in food safety risk monitoring of Wenzhou from 2020 to 2021 were conducted for isolation and identification, serotyping, biotyping, virulence gene detection, drug resistance analysis and molecular typing by pulse field gel electrophoresis(PFGE). Results A total of 31 strains of Yersinia enterocolitica were isolated in 356 samples, with an isolation rate of 8.71%. The main serotype of these isolates was O:5, and the main biotype was 1A. Only one strain of 4/O:3 type was found to carry ail, ystA, yadA and virF, while other strains only carried ystB or no virulence genes. The drug resistance rate of the isolates to cefoxitin and sulfamisoxazole was the highest(32.26%), and there were 4 strains with multiple drug resistance, accounting for 12.90%. 31 isolates were classified by PFGE, and 31 band types were obtained. Conclusion Yersinia enterocolitica is a potential contamination of livestock meat in Wenzhou City. Although the drug resistance rate of strains is at a low level, multiple drug resistant strains still exists. And the distribution of PFGE banding types is polymorphic.