[A study of the nucleotide sequence variability of rha locus genes of Yersinia pestis main and non-main subspecies].

A study of the structural and regulatory genes, determining rhamnose fermentation, that are located in the rha locus of the chromosome of Yersinia pestis main and non-main subspecies and of Yersinia pseudotuberculosis of serogroups I-III was performed. The nucleotide sequence of Y. pestis main subspecies differs substantially from those of non-main subspecies and Y. pseudotuberculosis by the presence of a nucleotide substitution in 671 bp location of rhaS gene resulting presumably in the Y. pestis non-main subsp inability to utilize rhamnose. This results in incapability of Y. pestis non-main subspecies to utilize rhamnose. Other nucleotide substitutions found in Y. pestis non-main subspecies strains influence only upon expression efficiency of this diagnostic criterion.