Pheno- and genotypic characteristics of Yersinia pestis strains from phylogroups 2.MED4 and 2.MED1 – etiological agents of 20th-century plague outbreaks in the Caspian Sea region

Abstract

We conducted a comparative analysis of the phenotypic and genotypic characteristics of plague pathogen strains from the 2.MED4 and 2.MED1 phylogroups, representing the main subspecies of the medieval Yersinia pestis biovar found in the plague foci of the Caspian Sea region, which were epidemically active in the 20th century. We evaluated the biochemical properties, nutritional requirements, and plasmid profiles of Y. pestis strains within the 2.MED4 and 2.MED1 phylogroups of the medieval biovar. We discovered the variability in the virulence-associated genes hemS , caf1M , and ssaJ in the strains of the 2.MED lineage. Our data on the phenotypic and genotypic characteristics of the medieval biovar can be used in laboratory diagnostics of the plague microbe and contribute to the understanding of genomic changes during the microevolution of this highly virulent biovar.