目的　探究鼠疫耶尔森菌生物型变异的遗传基础。方法　通过全基因组序列的比较分析 ,鉴定可能与生物型变异相关的基因突变 ,采用DNA测序和位点特异性PCR的方法 ,分析基因突变在鼠疫耶尔森菌自然分离株中的分布。结果　田鼠鼠疫自然疫源地菌株在毒力、生化表型和分子特征上与其他型别鼠疫耶尔森菌相差很大。所有脱氮阴性菌株的napA基因发生了突变 ,所有甘油利用阴性菌株的 glpD基因发生了突变 ,所有阿拉伯糖利用阴性菌株的araC基因发生了突变。结论　提出了一个新的生物型———田鼠型 ;相应糖醇代谢相关基因发生突变是 4个生物型变异的遗传基础。 Objective To explore the genetic basis of Yersinia pestis biological variation. Methods Genomic sequence analysis was used to identify possible gene mutations associated with biological variation. The DNA sequencing and site-specific PCR method were used to analyze the distribution of gene mutations in Yersinia pestis isolates. Results Vibrio plague natural foci in virulence, biochemical phenotype and molecular characteristics and other types of Yersinia pestis differ greatly. All of the denitrified-negative strains had a mutation in the napA gene, a mutation in the glpD gene in all glycerol-utilizing negative strains and a mutation in the araC gene in all negative strains of arabinose-utilizing bacteria. Conclusions A new type of vole (Microtus oeconomus) was proposed. Mutations of the related genes related to sugar metabolism were the genetic basis of the 4 biotypes.