预包装食品中金黄色葡萄球菌3种鉴定方法的比较

Comparison of 3 identification methods of Staphylococcus aureus in the prepackaged food

目的比较3种预包装食品中金黄色葡萄球菌鉴定方法的鉴定效果。方法使用金黄色葡萄球菌(ATCC25923)人工污染12种不同种类的预包装食品,按照GB4789.10-2016进行样品前处理和增菌,通过国家标准方法(GB 4789.10-2016)、VITEK2 Compact全自动微生物鉴定系统、基质辅助激光解吸电离-飞行时间质谱法方法,3种方法对上述样品中分离的疑似金黄色葡萄球菌进行鉴定,并对鉴定结果进行比较。结果 3种方法均能够对12种不同种类的人工污染预包装食品中分离的金黄色葡萄球菌进行准确有效的鉴定。相对于国标法,2种仪器鉴定方法无需进行后续溶血分析和血浆凝固酶实验,对操作人员技术要求更低,能够在更短的时间内获得鉴定结果。结论 2种仪器鉴定方法快速、可靠且操作简单,可以作为国标法的有效补充。

Objective To compare the identification effect of Staphylococcus aureus in 3 kinds of prepackaged food. Methods Twelve different kinds of prepackaged food were artificially contaminated with Staphylococcus aureus(ATCC 25923). According to the GB 4789.10-2016, the sample pretreatment and bacterial enrichment were performed. Furthermore, the suspected Staphylococcus aureus isolated from the above samples were identified by the national standard method, VITEK2 Compact and matrix assisted laser desorption/ionization-time of flight mass spectrometry(MALDI-TOF MS), and the identification results were compared. Results All suspicious colonies isolated from the 12 different kinds of artificial contaminated prepackaged food were identified as Staphylococcus aureus by the above three methods, and the results were consistent. Compared with the national standard method GB 4789.10-2016, the further hemolysis analysis and plasma coagulase test were unnecessary for the VITEK2 compact and MALDI-TOF MS. Furthermore, the technical requirements for operators were lower and the identification results could be obtained faster using the two automatic instrument methods. Conclusion The two identification methods using instruments are simpler to operate and faster to obtain the results, which could be used as an effective supplement to the current national standard method.