›› 2016, Vol. 43 ›› Issue (2): 493-498.doi: 10.16431/j.cnki.1671-7236.2016.02.030

• 疾病防治 • 上一篇    下一篇

乳品中大肠杆菌PMA-qPCR活菌检测方法的建立

盖冬雪1,2, 任洪林1, 卢士英1, 胡盼1, 孟宪梅2, 刘熙3, 宋德刚3, 金雯1, 张嵩1, 常江1, 刘艳艳4, 柳增善1   

  1. 1. 吉林大学人兽共患病研究所, 人兽共患病教育部重点实验室, 长春 130062;
    2. 吉林工商学院, 粮油食品深加工 吉林省高校重点实验室, 长春 130000;
    3. 广泽乳业有限公司, 长春 130000;
    4. 山东省东营市利津县第二中学, 东营 257400
  • 修回日期:2015-10-26 出版日期:2016-02-20 发布日期:2016-03-02
  • 通讯作者: 柳增善 E-mail:zsliu1959@sohu.com
  • 作者简介:盖冬雪(1990-),女,吉林长春人,硕士生,研究方向:动物性食品安全,E-mail:dongxue_gai@163.com
  • 基金资助:
    吉林省重点科技攻关项目(20140204065NY);吉林省世行贷款农产品质量安全项目(2011-Y36);吉林省科技发展计划项目(201205054);粮油食品深加工省高校重点实验室项目(2014001)

Establishment of PMA-qPCR Assay for Detection of Viable E.coli in Milk

GAI Dong-xue1,2, REN Hong-lin1, LU Shi-ying1, HU Pan1, MENG Xian-mei2, LIU Xi3, SONG De-gang3, JIN Wen1, ZHANG Song1, CHANG Jiang1, LIU Yan-yan4, LIU Zeng-shan1   

  1. 1. Key Laboratory of Zoonosis, Ministry of Education, Institute of Zoonosis, Jilin University, Changchun 130062, China;
    2. Key Laboratory of Grain and Oil Processing of Jilin Province, Jilin Business and Technology College, Changchun 130000, China;
    3. Ground Dairy Industry Co., Ltd., Changchun 130000, China;
    4. The Second Middle School of Lijin County in Dongying City, Dongying 257400, China
  • Revised:2015-10-26 Online:2016-02-20 Published:2016-03-02

摘要: 本试验旨在建立一种乳品中大肠杆菌PMA-qPCR活菌检测方法.优化qPCR检测方法,探究菌浓度为1×108 CFU/mL的大肠杆菌活菌悬液、热致死菌悬液细胞数来确定不同的PMA剂量、暗孵育时间、曝光时间对死菌抑制效果的影响,确定最佳PMA处理方案.结果表明,qPCR检测可特异性扩增大肠杆菌,1×108 CFU/mL的大肠杆菌经90 ℃水浴30 s全部致死后,采用10 μg/mL的 PMA暗孵育15 min后冰上曝光10 min为最佳处理方案,这种处理方案可最大程度抑制死细胞信号,而对活细胞几乎没有影响,样品中微生物初始浓度不低于1×108 CFU/mL时较稳定,得到标准曲线回归方程y=-3.356x+47.413,R2=0.9989,最低检测限为103 CFU/mL,加标样本检测结果与实际相符.该方法为利用PMA-qPCR检测食品中的活大肠杆菌杆菌奠定了基础.

关键词: 大肠杆菌; 叠氮溴化丙啶; qPCR; 计数

Abstract: In order to detect viable E.coli in milk,a new PMA-qPCR method was established.The influences of different PMA concentration,dark incubation time,exposure time on dead bacteria inhibition effect were determined by detection of the cell numbers of viable and heat-killed E.coli suspensions at concentration of 1×108 CFU/mL through fluorescence quantitative PCR (qPCR) method.The results showed that qPCR assay could specifically detect E.coli,and the viable E.coli must be exposed to 90 ℃ for 30 s in water bath to be lethal.The best treatment was 10 μg/mL PMA with 15 min of dark incubation time and 10 min of exposure time.This treatment could inhibit dead cell signals to a largest extend,while had little impact on aviable cells.The stability of PMA-qPCR assay was kept while the concentration of bacteria was more than 1×108 CFU/mL.The regression equation of standard curve was y=-3.356x+47.413,R2=0.9989,the lowest detection limit was 103 CFU/mL.The result of adding assay was agreed with the actual situation.This study laid a foundation for using of PMA-qPCR to detect the viable E.coli in food.

Key words: E.coli; PMA; qPCR; counting

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