3种方法检测食品中致泻大肠埃希氏菌检测能力验证结果分析

Capability verification results and analysis of 3 methods for detecting diarrheagenic Escherichia coli in food

中文关键词:  GB 4789.6-2016  多重实时荧光PCR  基质辅助激光解析电离飞行时间质谱法  致泻大肠埃希氏菌  能力验证

英文关键词:GB 4789.6-2016  multiplex real-time PCR  matrix-assisted laser desorption ionization time-of-flight mass spectrometry  diarrheagenic Escherichia coli  proficiency testing

中文摘要:

      目的 提高食品中致泻大肠埃希氏菌的检测能力, 促进实验室检测能力的提高。方法 参照GB 4789.6-2016《食品微生物学 致泻大肠埃希氏菌检验》方法进行检测, 采用VITEK 2 Compact全自动细菌鉴定系统进行生化鉴定、血清学鉴定, 对可疑菌落进行普通PCR确证试验。同时使用多重实时荧光PCR法以及基质辅助激光解析电离飞行时间质谱(matrix-assisted laser desorption ionization time-of-flight mass spectrometry, MALDI-TOF-MS)分析鉴定可疑菌落。结果 国标法和多重实时荧光PCR法能准确鉴定出目标菌, MALDI-TOF-MS可以检测大肠埃希氏菌, 但无法区分致泻大肠埃希氏菌和肠出血性大肠埃希氏菌。结论 3种方法各有优劣, 同时使用, 综合判断, 能确保试验结果准确快速。

英文摘要:

      Objective To improve the ability for the detection of diarrheagenic Escherichia coli in food, and promote the improvement of laboratory testing capabilities. Methods According to GB 4789.6-2016 Food microbiology-Detection of diarrheal Escherichia coli for detection, biochemical identification and serological identification were carried out by VITEK 2 Compact automatic bacterial identification system, and common PCR confirmation test was carried out on suspicious colonies. At the same time, multiple real-time fluorescence PCR and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) were used to analyze and identify suspicious colonies. Results The target bacteria could be accurately identified by national standard method and multi-real-time fluorescence PCR method. Escherichia coli could be detected by MALDI-TOF-MS, however, diarrheagenic Escherichia coli and enterohemorrhagic Escherichia coli couldn't be distinguished. Conclusion The combination and synthetic judgment of the 3 methods can ensure the accuracy of the testing result while each has advantages and disadvantages.