Abstract: Objective To investigate the genotypes and genetic characteristics of Yersinia pestis strains isolated from Kangbao county in Hebei province, China in 2017. Methods The DNA of three Y. pestis strains isolated from Kangbao county in Hebei province in 2017 was extracted by boiling method and kit extraction method. According to the literature, the primers of 22 different regions (DFRs) and pMT1 were synthesized and the DFR sites were amplified by PCR. The genotype was analyzed after agarose gel electrophoresis. Results The DFRs in the three strains were DFR02-05, DFR08-11, DFR14, DFR19-22, and pMT1, but not DFR01, 06, 07, 12, 13, and 15-18. The genotype was G20 after alignment. Conclusion The genotype of Y. pestis isolated from the plague foci in Hebei province in 2017 is G20 and different from G17 isolated previously. The emergence of new genotype provides a basis for further study of the genetic characteristics and epidemiological characteristics of the strain.

Key words: Yersinia pestis, Epidemiological characteristics, Genotyping

摘要： 目的 研究河北省康保县2017年分离的3株鼠疫耶尔森菌（鼠疫菌）的基因型及遗传特征。方法 采取水煮法和试剂盒提取法分别对2017年在康保县分离的3株鼠疫菌提取DNA，根据文献报道，选择pMT1和22个差异区段（DFR）位点，经过PCR扩增，琼脂糖凝胶电泳后分析其基因型别。结果 3株鼠疫菌的目标条带为DFR02～05、DFR08～11、DFR14、DFR19～22和pMT1，均缺少DFR01、06、07、12、13和15～18，经比对其基因型为G20。结论 2017年河北省鼠疫疫源地分离的3株鼠疫菌株基因型别均为G20，不同于以往分离的G17型，新基因型的出现为进一步研究菌株的遗传特征和流行病学特征提供了依据。

关键词: 鼠疫耶尔森菌, 流行特征, 基因分型