一起诺如病毒感染混合金黄色葡萄球菌肠毒素中毒相关急性胃肠炎暴发事件的实验室检测分析

目的对一起诺如病毒感染混合金黄色葡萄球菌肠毒素中毒相关急性胃肠炎暴发事件的实验室检测结果进行分析。方法采用实时荧光PCR方法检测6份病例呕吐物中的诺如病毒和8种常见致病菌。从呕吐物样本增菌液中分离培养金黄色葡萄球菌,采用PCR方法检测增菌液的金黄色葡萄球菌肠毒素基因。利用酶联免疫吸附试验检测5株金黄色葡萄球菌分离株的肠毒素、利用PCR方法检测其肠毒素基因并进行spa分型分析。结果共采集到6份呕吐物标本,其中5份诺如病毒阳性,2份金黄色葡萄球菌耐热核酸酶基因nuc阳性。其中5份呕吐物增菌液nuc基因阳性,4份seb基因阳性,1份sea基因阳性。共分离到5株金黄色葡萄球菌,分为3种spa型(t701、t437和t4209)。金黄色葡萄球菌肠毒素的基因PCR检测结果和酶联免疫吸附试验结果存在差别。结论本次急性胃肠炎暴发事件可能由诺如病毒感染混合金黄色葡萄球菌肠毒素中毒共同导致。

Laboratory detection for an acute gastroenteritis outbreak caused by Norovirus and Staphylococcus aureus enterotoxins

ObjectiveTo analyze the laboratory detection results for an acute gastroenteritis outbreak.MethodsTaqMan real-time PCR was performed for the detections of Norovirus and 8 major bacteria pathogens by using the original 6 vomit samples collected from patients. PCR for the enterotoxin (SE) genes of Staphylococcus aureus was performed by using the S. aureu strains cultured in enriched vomit samples. ELISA was performed for the detection of SEs of 5 S. aureu strains, and PCR was used for SE gene detection and spa typing.ResultsSix original vomit samples were collected in the outbreak. Among them, 5 were positive for Norovirus and 2 were positive and nuc gene of S. aureus in real-time PCR. Five enriched vomit samples were positive for nuc gene, among them, 4 and 1 were positive for seb gene and sea gene, respectively. Five S. aureus isolates were obtained from 5 enriched vomit samples of the patients, and were divided into 3 spa types (t701, t437 and t4209). There was a difference in SE gene detection of S. aureu between PCR and ELISA.ConclusionLaboratory analysis indicated that this gastroenteritis outbreak may be caused by the infection of Norovirus plus effect of SEs of S. aureu.