MOLECULAR CHARACTERIZATION OF A POPULATIO N OF TICK-BORNE ENCEPHALITIS-VIRUS FROM THE SOUTHERN SIKHOTE-ALIN FOCUS

Molecular characteristics of 38 strains of tick-borne encephalitis (TB E) virus isolated in the Southern Sikhote-Alin focus were studied usin g 10 synthetic oligonucleotide probes complementary to the genomic RNA of the Sofyin strain. The isolated strains were divided into 4 groups , depending on the source of isolation: 1) strains isolated from Ixode s persulcatus (n=8); 2) from the brain of patients dead from TBE (n=10 ); 3) from the blood of patients with the febrile form of TBE (n=7); a nd 4) from the blood of patients with an unapparent infection (n=13). The total level of hybridization in the four groups was as follows: 61 .8, 75.2, 55.8, and 35.2%. The ''tick'' strains with a great variety o f the genofund are regarded as the stock group of the natural TBE viru s population, 40% of which are strains close by their characteristics to avirulent strains of TBE virus.