食品科学

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武汉肉类食品中大肠杆菌O157∶H7分离株stx亚型和毒力特征分析

郑冬冬1,毕旺来1,王宏勋2,刘志国1,丁洪波1,李 睿1,3,*   

  1. 1.武汉轻工大学生物与制药工程学院,湖北 武汉 430023;2.武汉轻工大学食品科学与工程学院,
    湖北 武汉 430023;3.农产品加工湖北省协同创新中心, 湖北 武汉 430023
  • 出版日期:2014-04-25 发布日期:2014-05-13
  • 通讯作者: 李 睿
  • 基金资助:

    国家高技术研究发展计划(863计划)(2012AA101703-3);
    武汉市科技局国际科技合作计划项目(2013030409020113);武汉轻工大学研究生创新基金项目(2012cx019)

stx Genotypes and Virulence Characteristics of E. coli O157:H7 Strains Isolated from Meat Products Commercialized in Wuhan

ZHENG Dong-dong1, BI Wang-lai1, WANG Hong-xun2, LIU Zhi-guo1, DING Hong-bo1, LI Rui1,3,*   

  1. 1. College of Biological and Pharmaceutical Engineering, Wuhan Polytechnic University, Wuhan 430023, China;
    2. College of Food Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, China;
    3. Hubei Collaborative Innovation Center for Processing of Agricultural Products, Wuhan 430023, China
  • Online:2014-04-25 Published:2014-05-13
  • Contact: LI Rui

摘要:

从22 家市场销售的117 份肉类食品中分离出4 株大肠杆菌O157∶H7菌株,经PCR检测这4 株菌的stx、hly、 eae毒力基因均为阳性。采用聚合酶链式反应(polymerase chain reaction,PCR)法对这4 株菌的stx亚型进行鉴定。 3 株菌同时携带stx1、stx2基因,且均为stx1a、stx2a亚型。菌株EC5.11仅携带stx2基因,但在所有的stx2分型PCR反 应中都为阴性。用PCR扩增该菌株stx2基因全长并克隆测序,序列分析结果表明EC5.11志贺毒素基因为stx2c亚型。 采用Vero细胞毒性实验检测这4 株菌产志贺毒素的状况,结果显示这些菌株都具有一定的Vero细胞毒性。

 

关键词: 大肠杆菌O157∶H7, 志贺毒素, stx亚型, Vero细胞毒性

Abstract:

A total of 117 raw meat samples were collected from 22 markets in Wuhan, China and four E. coli O157:H7
strains were isolated from these meat samples, which were positive for stx, hly and eae genes. The stx variant genes were
further subtyped by polymerase chain reaction (PCR) using sequence-specific primers targeting each stx variant. Three
isolates were found to carry both stx1 and stx2 genes, and the prevalent stx genotypes were stx1a and stx2a. One isolate EC
5.11 was found to carry only stx2 gene but it could not be subtyped by PCR assay. The entire stx2 gene was then amplified from
EC 5.11, cloned into a vector and sequenced. Sequencing data showed that the stx2 gene of EC5.11 was 100% identical to the
published sequences of stx2c. The production of Shiga toxin from the four isolates was confirmed by Vero cell toxicity assay.

Key words: E. coli O157:H7, Shiga-toxin, stx genotype, Vero cytotoxicity

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