食品科学 ›› 2012, Vol. 33 ›› Issue (22): 217-220.

• 分析检测 • 上一篇    下一篇

PMA-qPCR方法快速检测活的E.coli O157:H7

李聪聪1,余以刚1,邱 杨2,李美玲1,肖性龙1,*,吴 晖1   

  1. 1.华南理工大学轻工与食品学院 2.东莞出入境检验检疫局
  • 收稿日期:2011-09-29 修回日期:2012-10-23 出版日期:2012-11-25 发布日期:2012-11-20
  • 通讯作者: 肖性龙 E-mail:fexxl@scut.edu.cn
  • 基金资助:

    2009年度广东省自然科学基金项目项目;2010年东莞市高等院校科研机构和医疗卫生单位科技计划项目;2011年广东省科技计划项目;2011年华南理工大学中央高校基本科研业务费项目

Rapid Detection of Live E. coli O157: H7 by PMA-qPCR Method

  • Received:2011-09-29 Revised:2012-10-23 Online:2012-11-25 Published:2012-11-20

摘要: 建立将叠氮溴化丙锭(PMA)与定量PCR(qPCR)技术结合,用于检测热灭活菌背景条件下的大肠杆菌活菌的方法。结果表明:5min以上的强烈光照可以使PMA与DNA共价交联,同时完全钝化游离的PMA以避免“假阴性”结果;抑制死菌DNA扩增的最低PMA质量浓度为10µg/mL,不抑制活菌DNA扩增的最高PMA质量浓度为20µg/mL。当活菌/总菌大于1%时,经PMA预处理,可以消除热灭活菌DNA的干扰,实现对活菌的定量检测。

关键词: 叠氮溴化丙锭, 定量PCR, 活菌, 检测

Abstract: In this work, a method to detect live E. coli O157:H7 was established using propidium monoazide (PMA) coupled with quantitative polymerase chain reaction (qPCR). The minimum inhibitory concentration against DNA amplification from dead bacteria was 10 µg/mL, and PMA did not inhibit DNA application from live bacteria at concentrations equal to or lower than 20 µg/mL. Covalent cross-linking of PMA with DNA was induced by strong light illumination for 5 min and meanwhile, free PMA was completely inactivated, resulting in the avoidance of false negative results. When the live to dead bacteria ratio was more than 1%, PMA pretreatment allowed the elimination of DNA interference from thermally inactivated bacteria and therefore live bacteria could be quantified.

Key words: propidium monoazide (PMA), quantitative polymerase chain reaction (qPCR), live bacteria, detection

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