We performed a molecular genetic analysis of Yersinia pestis strains isolated in the Ural-Embensky desert natural plague focus area in the twentieth century. We studied 24 strains of Y. pestis isolated on this territory since 1945 to1991, as well as 21 strains of Y. pestis from adjacent territories. All of the strains studied from the Ural-Embensky natural focus of plague belonged to the highly virulent and epidemically signifi cant medieval biovar of the main subspecies Y. pestis.
