RESUMEN
We typed Yersinia pestis isolated from plague foci of Shaanxi Province using different region (DFR) and analyzed epidemiological characteristics.Twenty-three DFRs primers and PMT1 (plasmid) primer were used to verify the DFR genomovars and 48 Yersinia pestis were involved to analyze DFR profiles and epidemiological characteristics.In the same year,the genotypes of Yersinia pestis isolated from different infected vector and animals were basically the same.Three genomovars named Genomovar 11,17,and 20 were verified in 48 Yersinia pestis strains in Shaanxi Province.The main genotypes were different in different epidemic years.In 1987-1988 and 2000-2001 years,genomovar 17 was major genomovar and genomovar 20 in 2006 year.In conclusion,the dominant genotypes were different in different epidemic years.As time goes on,DFR genomovars of Yersinia pestis undergone the evolution of gene deletion,which changes genomovar 17 into genomovar 20.