目的 利用差异区段（DFR）基因分型方法鉴别沙鼠型鼠疫耶尔森菌（鼠疫菌）和鼠疫菌EV76疫苗株。方法 采取水煮法对2015年内蒙古自治区杭锦旗、2013年宁夏回族自治区银川市和2003年河北省康保县分离的6株沙鼠型鼠疫菌和鼠疫菌EV76疫苗株提取DNA，引物选用文献报道中的22个差异区段和pMT1，PCR扩增经琼脂糖凝胶电泳后分析其基因型别。结果 沙鼠型鼠疫菌DFR基因型分别为G11、G17和G20。G11缺失位点为DFR01、06、07、13、15、16和17，G17缺失位点较G11增加DFR18，G20缺失位点较G17增加DFR12；鼠疫菌EV76疫苗株的缺失位点则为DFR01、02、04和10。结论 利用DFR基因分型方法能快速区分沙鼠型鼠疫菌和鼠疫菌EV76疫苗株，可避免工作中因菌苗污染而造成分离到鼠疫菌的假象，鼠疫菌株基因型别的鉴定可以快速追溯疫情来源。

Objective To identify Yersinia pestis from the Mongolian gerbils and EV76 bacteria of plague by different region (DFR) fragment genotyping. Methods The DNA of 6 strains of Y. pestis and EV76 isolates was extracted by boiling method from Hangjinqi of Inner Mongolia in 2015, Yinchuan city of Ningxia Hui Autonomous Region in 2013, and Kangbao county of Hebei province in 2003. The DFR primers according to a report were synthesized by biological company, then amplified by PCR, analyzed genotype through agarose gel electrophoresis. Results The DFR genotypes of Y. pestis from Mongolian gerbils were G11, G17, and G20. The absent points of G11 were DFR01, 06, 07, 13, 15, 16, and 17; DFR18 was also absent for G17 in addition to the above; The absent point of G20 also included DFR12 in addition to G17. The absence DFRs of EV76 were 01, 02, 04, and 10. Conclusion Using the differential fragment genotyping method can quickly distinguish Y. pestis isolates from Mongolian gerbils and EV76. At the same time, it is possible to trace the source of the epidemic rapidly by identifying the genotype of wild strains.