[Genotyping of the Francisella tularensis strains isolated from natural foci of tularemia in the Rostov region by multilocus VNTR analysis].

On the basis of an analysis of the VNTR alleles' distribution in 109 strains of F. tularensis it was established that 19 genotypes of the disease causative agent circulated in the Rostov Region from 1945 to 2002. The microbe-provoked infection episodes can be divided into polyclonal, monoclonal and cluster ones. A retrospective analysis of the genotypes' distribution is indicative of that strains of similar or of closely-related genotypes circulate simultaneously in the studied territory. All investigated F. tularensis strains could be differentiated into two groups; strains, whose genotypes are encountered almost evenly within the entire Region's territory, belong to group 1; and strains of group 2 displayed a trend towards being geographically bound. Isolations of cultures with similar (close) genotypic features made in prolonged time periods suggest that a part of F. tularensis clones can persist for a long time in environmental foci. A set of strains described by genotype can provide a foundation for a database of the tularemic microbe culture within the geo-information system of the South Federative Okrug of Russia.