目的 了解近几年我国鼠伤寒沙门菌临床分离株的分子分型特点,为以实验室为基础的食源性暴发的发现提供基线数据.方法 根据国际PulseNet公布的沙门菌PFGE分型方案及鼠伤寒沙门菌多位点MLVA分型方法,对2006-2010年分离自我国7个省(直辖市)的294株鼠伤寒沙门菌进行分子分型分析.结果 294株鼠伤寒沙门菌经XbaⅠ酶切,脉冲场凝胶电泳后,获得87种带型,其分辨能力(D值)为0.905 0.对其中的主要优势带型JPXX01.CN0001菌株76株、JPXX01.CN0006菌株40株和JPXX01.CN0073菌株24株进一步用第2种内切酶BlnⅠ酶切后,分别获得10、22和17种带型.应用MLVA分析,获得198种型别, D值为0.992 9.对流行病学调查显示为鼠伤寒沙门菌暴发病人和食物来源的菌株进行PFGE双酶切及MLVA分型,两种分型方法获得一致性结果,均显示这些菌株具有明显的聚集性.结论 两种分子分型结果显示我国鼠伤寒沙门菌临床分离株具有遗传多样性,MLVA分型方法的分辨能力高于PFGE,在确认鼠伤寒沙门菌引起的暴发事件时,采用需时较短,操作方便的MLVA分型方法可满足菌株聚集性分析.%With the application of standard pulse-field gel electrophoresis(PFGE) and multiple loci VNTR analysis (ML-VA) on PulseNet International network , 294 isolates of S. typhimurium from seven provinces in China during 2006 to 2010 were typed . The results showed 87 PFGE patterns after pulse-field gel electrophoresis with discrimination index (D) of 0 .9050 , containing three dominate; patterns , JPXX01 .CN0001 , JPXX01 .CN0006 and JPXX01 .CN0073 .It included 76 ,40 and 24 S. typhimurium isolates which were further digested with the second enzyme Bln I to achieve additional 10 ,22 and 17 patterns , respectively . Meanwhile , 198 variant patterns were obtained with MLV A method and the D value reached 0 .9929 , indicating the discriminatory ability of the MLV A superior to PFGE for S. typhimurium snbtyping . Both PFGE and MLV A methods could effectively distinguish outbreak strains from sporadic isolates . The variant patterns produced by the two molecular typing methods indicated genetic diversity among clinical S. typhimurium isolates in China. And MLV A with the characterization of higher discriminatory power , time saving and easy manipulation was suitable for cluster analysis when early detecting outbreaks caused by S. typhimurium .
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