Comparative analysis of the genome regions associated with virulence in original classic and El Tor Biovars of Vibrio cholerae strains

The comparative analysis of the genome regions associated with virulence in various V. cholerae strains: classical biovar, as well as typical and genetically altered strains of El Tor biovar was performed with the use of PCR assays and fragment sequencing. V. cholerae classical biovar genome was demonstrated to be more stable in comparison with the same in V. cholerae El Tor biovar. Within the genome of El Tor vibrios there were identified extensive variable regions carrying pathogenicity genes. It was also found that unlike classical cholera vibrios, in the V. cholerae El Tor genome there is absent CRISPR-system limiting horizontal transfer of the genes. The obtained data concerning these structural peculiarities of V. cholerae El Tor genome may be used in the delivery of the new generations of gene-diagnostic preparations and for improvement of molecular-epidemiological monitoring in case of cholera.