脉冲场凝胶电泳分型追溯江西省霍乱暴发传染源

目的分析2006年5月江西省聚餐暴发霍乱疫情的分离菌株与常规监测在外环境及水产品中分离的霍乱弧菌之间分子分型特征和遗传相关性。方法利用聚合酶链反应检测霍乱毒素基因，用脉冲场凝胶电泳（PFGE）对菌株进行分子分型，所得结果以BioNumerics V4．0软件UPGMA方法进行聚类分析。结果30株与暴发相关分离菌株中，无论来自病例、带菌者、疫区污水、水产品的菌株均为产毒株。30株O139群霍乱弧菌以NotⅠ酶切后PFGE可分为4个型别。从甲鱼、牛蛙分离的O139群霍乱弧菌的型别与此次暴发的优势PFGE型别一致，并且也为产毒株。两起暴发包括多起聚餐，从中分离的菌株优势型别相同，传播媒介为甲鱼、牛蛙，均购于同一水产批发部，说明为同一传染源。结论携带O139群霍乱毒素基因的甲鱼、牛蛙是引起本次多起聚餐暴发霍乱的主要传染源。

Study on the application of pulsed-field gel electruphoresis regarding infection sources identification during an outbreak of Vibrio cholerae in Jiangxi province

OBJECTIVE: To study the correlation between Vibrio cholerae strains isolated from natural enviroment and fishery products and the source of infection during V. cholerae outbreaks. METHODS: Cholera toxin gene was detected by polymerase chain reaction (PCR) amplification. Pulsed-field gel electrophoresis (PFGE) was used to subtype the isolates. Results of PFGE were analyzed and clustered by BioNumerics software (Version 4.0). RESULTS: During the outbreaks, a total number of thirty O139 V. cholerae related serogroups were collected from patients, carriers, sewage and fishery products were identified and proved to be toxigenic. They could be clustered into four PFGE patterns when digested by Not I. These two V. cholerae outbreaks were caused by the same source of infection because of the following reasons: (1) PFGE patterns of the predominant strains isolated from two outbreaks were identical; (2) they were identical to the PFGE patterns of the strains isolated from the green turtle and rana catesbiana which were bought from the same wholesale store. CONCLUSION: Green turtle and rana catesbiana that were contaminated by toxigenic O139 V. cholerae strains seemed to be the source of infection causing the O139 V. cholerae outbreaks in Jiangxi province. Rapid laboratory surveillance and epidemiologic investigation were important in identifying the source of infection during the outbreaks of V. cholera.