[The genetic typing of strains in the genus Francisella using universal probes]

The determination of the genetic relationship of bacteria of the genus Francisella and their differentiation is one of the topical tasks of the epidemiology and infectology of F. tularensis, the causative agent of tularemia, belonging to this genus. To solve this task, investigation was carried out with a view to the determine the possibility of the genomic typing of Francisella. Genomic typing was based on the use of the hybridization of fragments of Francisella chromosomal DNA, split by restrictases EcoRI and Pstl, with DNA probes. As probes, "minisatellite" sequences of bacteriophage M13 DNA or Helicobacter pylori rDNA were used. The possibility of interspecific genomic typing of F. tularensis, F. novicida and F. philomiragia by the above-mentioned methods was established. The intraspecific typing of F. tularensis by the phenotypical sign of virulence was possible with the use of the hybridization of chromosomal DNA with bacteriophage M13 probe. The use of rDNA probe proved to be effective for the determination of subspecies of the causative agent of tularemia. The possibility of using the combination of these two methods for more complete characterization of the genomic polymorphism of Francisella, the determination of their genetic relationship and their differentiation is discussed.