脉冲场凝胶电泳方法在霍乱暴发溯源中的应用

目的应用脉冲场凝胶电泳(PFGE)方法对不同类型的霍乱暴发事件进行分析,了解霍乱菌株的PFGE特征,追溯菌株的来源及其演变过程,探讨霍乱暴发流行的特点和规律。方法采用限制性内叨酶NotⅠ,对2003—2005年广州地区霍乱暴发疫情中41株霍乱弧菌进行PFGE分子分型,用BioNumerlcs Version 4.0软件(复选Dice相关系数和UPGMA方法)进行聚类分析,并与噬菌体-生物分型及致病相关基因分型方法作比较。结果在霍乱暴发事件中,PFGE能有效地区分流行病学上密切相关菌株与无关菌株,与噬菌体-生物分型和致病相关基因分型方法相比具有更高的分辨能力。结论PFGE分型可揭示人和环境分离的霍乱菌株之间的流行病学联系,为霍乱疫情溯源提供分子流行病学证据和支持。

Application of pulse-field gel electrophoresis analysis in the source-tracking of cholera epidemics

Objective To apply pulse-field gel electrophoresis analysis(PFGE)in the analysis of cholera outbreak events and to determine the molecular epidemiological characteristics of Vibrio cholerae (V.cholerae)isolates.Methods PFGE using restriction enzyme Not I was employed in the molecular subtyping of forty-one strains of V.cholerae isolated in cholera outbreak events from 2003 to 2005 in Guangzhou area and PFGE patterns were analyzed by BioNumerics Version 4.0 software to perform cluster analysis.Pattern profiles were compared by utilizing of Dice coefficient and UPGMA(unweighted pair group method with arithmetic averages).Comparison of PFGE typing results was performed with phage-biological typing and pathogenicity-associated genes typing.Results In cholera outbreak events,PFGE could discriminate epidemiologically related and unrelated strains,having more discriminatory power than phage- biological typing and pathogenicity-associated genes-typing.Conclusions Molecular sub-typing by PFGE could disclose the epidemiological relationships of strains from humans and the environment,providing molecular epidemiological evidence and support for the source-tracking of cholera outbreak events.