引起一起食物中毒的副溶血性弧菌的同源性分析

摘要

目的 应用脉冲场凝胶电泳(PFGE)对引起一起食物中毒的副溶血性弧菌(VP)分离株作同源性分析,为VP引起的食物中毒溯源及流行病学研究提供科学的技术支持.方法 对7份患者肛拭、5份厨师肛拭、5份留样食品以及8份环境样本进行VP分离鉴定、血清学分型、毒力基因检测及PFGE分析.结果 分离自患者肛拭样本(4株)和食品(水产品)样本(2株)的VP血清型均为O3:K6型,毒力基因检测显示跨膜转录激活蛋白基因(foxR)阳性、耐热直接溶血素基因(tdh)阳性、耐热相关溶血素基因(trh)阴性.分离自食品(蔬菜)样本(2株)的VP血清型为O4:K2型,毒力基因检测显示foxR阳性、tdh阴性、trh阴性.患者与食品(水产品)分离株的PFGE分型图谱一致,具有高度同源性.结论 此次食物中毒为O3∶ K6型VP污染水产食品所致.PFGE技术具有很强的菌株同源性分析能力,对于掌握病原菌流行规律具有重要意义.%Objective To study on homology of Vibrio parahaemolyticus (VP) isolated from a case of food poisoning by pulsed-field gel electrophoresis (PFGE),and to provide a reference for the traceability of VP causing food poisoning.Methods A total of 7 cases and 5 cases of anal swabs from patients and kitcheners,5 cases from food retentions and 8 cases from environmental samples were collected and determined.Biochemical identification,serological typing,virulence gene detection and PFGE were performed.Results The serotype of VP isolated from anal swabs (4 isolates) and food (fishery product,2 isolates) was O3 ∶ K6,and there existed transmembrane transcriptional activation protein gene (tox R)-positive,thermostable direct haemolysin (tdh)-positive and thermostable-related haemolysin (trh)-negative.The serotype of VP isolated from food (vegetable,2 isolates) was O4:K2.There existed tox R-positive,tdh-negative and trh-negative.They had the same PFGE pattern,showing high homology.Conclusions The cause of this food poisoning is fishery product polluted by VP of O3:K6 serotype.PFGE has high resolution which enables itself to identify products and trace infection sources.