EPIZOOTOLOGICAL AND PHYLOGENETIC EVALUATION OF THE BOVINE LEUKEMIA VIRUS IN RUSSIAN FEDERATION

Abstract

The genetic characterization of BLV is an important task in scientific research in many countries of the world. According to the sequenced gene region - env BLV isolates allocated in different geographical locations of the world, up to 10 different genetic groups of the virus were identified and classified. Acknowledgments: The research was carried out at the expense of the Russian Science Foundation grant (project No. 17-76-10051). As part of the research, we monitored the epizootic situation of the BLV in Russia. Groups of animals (n=50) Holstein-Frisian (imported breed) and Russian Black Pied (local breed) were selected, belonging to agricultural organizations of the Tyumen region. Serological screening methods (ELISA, AGID) were used in cattle to identify infected animals. Immunological evaluation of animals in all test groups is given. A primary A nested-PCR study was performed, which resulted in a fragment of the env 444 bp gene in the studied samples. RFLP analysis of this fragment allowed to establish that in 94 % of the samples there was a «Belgian type» of the leukemia virus, in 4 % of samples - «Australian» and in 2 % - a «mixed type». All samples were sent for NGS sequencing. By phylogenetic evaluation of the BLV genome env site in the isolated samples and the immunological evaluation of the infected animals, new data will be obtained that will allow updating information on the genetic groups of the BLV in the territory of the Russian Federation.