【摘要】 目的 对福氏2a志贺菌质粒DNA进行基因分型，提高福氏2a志贺菌菌痢爆发流行时同源克隆的鉴定水平。 方法 对8株福氏2a志贺菌进行质粒图谱及质粒限制性酶切图谱分析。 结果 此次菌痢爆发期间分离的8株福氏2a志贺菌具有两种不同的质粒图谱特征(PPⅠ、PPⅡ型)，其中2株病例密切接触者分离株J98101(PPⅡ型)和J9826(PPⅠ型)分属不同克隆。除上述两种质粒图谱特征外，同属PPⅠ型质粒图谱特征的J9871具有独特的质粒限制性酶切图谱特征ReⅢ型。 结论 本次爆发偶合有部分散发病例。相对于传统表型分型方法(生化反应、血清型)而言，质粒DNA分析具有更高的分辨率，它提供的遗传学信息更为丰富、直接、精细。

    【关键词】 志贺氏菌，福氏;多态性，限制性片段长度;质粒

    Plasmid DNA polymorphism analysis in an outbreak of S.flexneri2a

    CHENG Hui ，ZHANG Zhi-hua ，YANG Lin-sheng ，HAO Jia-hu ，HUANG Fen ，ZHONG Wen-long ，WANG Hong ，YU Shou-yi .

    Department of Epidemiology and Statistics，School of Public Health，Anhui Medical University，Hefei 230032，China;Jiangmen Center for Disease Control and Prevention，Jiang-men 529000，China;Department of Epidemiology，Southern Medical University，Guangzhou 510515，China

    【Abstract】 Objective To identify homogenous clones of S.flexneri2a by gene distribution polymor-phism of plasmid DNA of S.flexneri2a.Methods Plasmid profile and plasmid DNA restriction endonu-clease analysis were carried out on8strains of S.flexneri2a.Results There were two different plasmid profile patterns in8of S.flexneri2a(PPⅠ ......