食物中毒事件中致病菌肠毒素检测和分子分型研究

目的 对一起食物中毒事件样本进行检测,查明食物中毒原因,并对分离菌株进行相关性分析。方法 参照国家标准方法GB4789.10-2016,对采集样本进行细菌学检验。应用酶联免疫吸附法(ELISA)检测葡萄球菌肠毒素。通过脉冲场凝胶电泳(PFGE)进行分子分型,分析菌株之间的相关性。结果 食物中毒事件中5名患者洗胃液、食物、分离菌株,均检测出E型葡萄球菌肠毒素。3株分离菌株PFGE分子分型提示来源不同克隆株,除了产生E型葡萄球菌肠毒素外,还有B、C、D型。结论 该起食物中毒由不同PFGE型别的产毒金黄色葡萄球菌污染食物引起,菌株产葡萄球菌肠毒素的型别不完全相同。金黄色葡萄球菌引起的食物中毒应关注多污染源及菌株肠毒素基因表达情况。

Molecular typing and enterotoxin detection in food poisoning case

Objective To find the cause of a food poisoning by testing its samples and conduct correlation analyses on the isolated strains. Methods Bacterial tests for samples from the food poisoning were carried out according to GB4789.10-2016. The ELISA method was applied to detect staphylococcal enterotoxins. Pulsed field gel electrophoresis (PFGE) was conducted for the molecular typing in order to analyze the correlation of strains. Results SEE was detected in the gastric lavage fluid samples of 5 patients and in the food and the isolated strains. PFGE molecular typing of 3 isolated strains indicated different sources of clone strains, and SEB, SEC and SED were generated besides SEE. Conclusion The food poisoning was caused by food contaminated by enterotoxigenic Staphylococcus aureus of different PFGE types, and the strains generated different types of staphylococcal enterotoxins. In the food poisoning caused by Staphylococcus aureus, more importance should be attached to the source of pollution and the gene expression of the enterotoxins.