食品科学 ›› 2010, Vol. 31 ›› Issue (8): 212-215.doi: 10.7506/spkx1002-6300-201008047

• 分析检测 • 上一篇    下一篇

PCR 法检测食品中大肠杆菌O157:H7

巢强国1,杨学明2,葛 宇1,熊 薇1,曲勤凤1,王瑞元2   

  1. 1.上海市质量监督检验技术研究院 2.华东理工大学生物工程学院
  • 收稿日期:2009-03-03 修回日期:2009-12-03 出版日期:2010-04-15 发布日期:2010-12-29
  • 通讯作者: 葛宇 E-mail:ghgygyc@126.com
  • 基金资助:

    上海市质量监督检验局项目(2007-21)

Rapid PCR Detection of Enterohemorrhagic Escherichia coli O157:H7 in Foods

CHAO Qiang-guo1,YANG Xue-ming2,GE Yu1,XIONG Wei1,QU Qin-feng1,WANG Rui-yuan2   

  1. 1. Shanghai Institute of Quality Inspection and Technical Research, Shanghai 200233, China;
    2. School of Bioengineering, East China University of Science and Technology, Shanghai 200237, China
  • Received:2009-03-03 Revised:2009-12-03 Online:2010-04-15 Published:2010-12-29
  • Contact: GE Yu1 E-mail:ghgygyc@126.com

摘要:

对大肠杆菌O157:H7 型菌株的各毒力基因及基因组中的特异序列进行了设计和比对,确定292bp 的检测引物。常规定性PCR 和实时定量PCR 证明该引物特异性强。模拟样品的前增菌实验结果表明本方法可以在原样品活菌浓度约2.0CFU/mL 时通过16h 增菌后检测出来,总的检测时间可以控制在24h 内。本实验建立的PCR 方法可用于食品中大肠杆菌O157:H7 的快速测定。

关键词: 大肠杆菌O157:H7, 食源性致病菌, 特异序列, PCR

Abstract:

Genomic comparisons were carried out on Escherichia coli virulence genes and genome-specific sequences, which were located in the genomes of Escherichia coli serotype O157:H7 strains released in the GenBank. One pair of primers specific for ECs3032 genes was exploited for the amplification to give a 292 bp PCR product. Conventional qualitative PCR and real-time quantitative PCR assays showed higher specificity of the primers. The assays were used for detecting Escherichia coli O157:H7 in ground beef initially inoculated at the dosages of 2, 20, or 200 CFU/mL after 2, 11, 16 h and 20 h of enrichment at 37 ℃ in modified EC broth. Escherichia coli O157:H7 was detected in all samples inoculated. The whole detection procedure was finished within 24 hours with a sensitivity of 2.0 CFU/mg beef sample using the PCR assay established in this study. Thus, an effective method is provided for the rapid PCR detection of Escherichia coli in foods.

Key words: enterohemorrhagic Escherichia coli O157:H7, foodborne pathogenic bacteria, specific sequence, PCR

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