RESUMO
Primary structures of gene fragments of E protein (160 n.b.) have been determined for 29 tick-borne encephalitis (TBE) strains isolated from different parts of a territory. Analysis of homology of nucleotide sequences of these strains and data on 6 TBE strains published by other authors showed that they can be divided into 6 groups (genotypes) by the following gene typing criteria: strain structure within the genotypes differing by no more than 9%, differences between strains of different genotypes are at least 12%. Based on these criteria, the prototype strains of the Far Eastern antigenic variant (Sofyin), Central European antigenic variant (Neudoerfle), and Vergina strain form different genotypes 1, 2, and 6, respectively. East Siberian strain Aina and Ural Siberian strain Lesopark-II belong to the same TBE virus genotype 3; two-thirds of analyzed strains belong to this genotype. Genotype 4 is represented by one strain 178-79, and genotype 5 by strain 886-84, both isolated in East Siberia.
Assuntos
Encefalite Transmitida por Carrapatos/genética , Variação Genética , Proteínas do Envelope Viral/genética , Sequência de Bases , Primers do DNA , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Viral , Homologia de Sequência do Ácido Nucleico , Especificidade da EspécieRESUMO
Tick-borne encephalitis (TBE) virus strains isolated in different geographic areas were characterized by changes in electrophoretic mobility (EPM) of virus-specific proteins. Analysis of EPM of intracellular virus-specific protein E and other high molecular proteins of 42 TBE virus strains revealed similarity among the majority of them, with the exception of several strains including the Sophyin strain (Far-Eastern subtype). The most marked variability in the electrophoretic behavior of virus-specific proteins was observed with low molecular proteins prM, ns4b, ns2a.
Assuntos
Vírus da Encefalite Transmitidos por Carrapatos/química , Proteínas Virais/análise , Animais , Comunidade dos Estados Independentes , Eletroforese em Gel de Poliacrilamida , Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Humanos , Camundongos , Peso Molecular , Testes de Precipitina , Inoculações Seriadas , Carrapatos/microbiologia , Proteínas Virais/isolamento & purificaçãoRESUMO
Hybridization experiments with RNA of 143 tick-borne encephalitis (TBE) virus strains isolated in different parts of the distribution area were used to study the reactivity of kDNA- and a set of 10 synthetic deoxyoligonucleotide probes. The kDNA probe under certain conditions was shown to hybridize with RNA of all the strains under study, and under other (strict) hybridization conditions did so selectively with a small number of strains. The capacity of oligonucleotide probes for hybridization with RNA of TBE virus strains varied from 12% to 100%. The differences in the hybridization activity of kDNA- and oligonucleotide probes complementary to the genomes of the Sophyin strain (Far-Eastern subtype) and Neudorffle strain (Western subtype) with TBE virus strains were used for differentiation of the strains into six genetic variants. Comparison of the reactivity of molecular probes in experiments with RNA of TBE virus strains and viruses of the TBE complex showed that the differences of the strains belonging to different genetic variants from the prototype Sophyin strain were comparable to those of some members of the TBE complex, with the exception of Powassan virus. These data attest to the necessity of further studies dealing with specification of the taxonomy of TBE complex viruses.
Assuntos
Sondas de DNA/genética , DNA Viral/genética , DNA/genética , Vírus da Encefalite Transmitidos por Carrapatos/genética , Genoma Viral , Sondas de Oligonucleotídeos/genética , RNA Viral/genética , Animais , Sequência de Bases , Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Variação Genética/genética , Dados de Sequência Molecular , Hibridização de Ácido Nucleico/métodos , RNA Viral/isolamento & purificação , Federação Russa , Carrapatos/microbiologiaRESUMO
Geographic distribution of 185 tick-borne encephalitis (TBE) virus strains isolated in 8 physico-geographic areas and classified into six genetic variants was analysed. The strains of genetic variant I homologous to the Sophyin prototype strain were found to occur predominantly in the Far East and also frequently found in Western and North-Western parts of the East European plain. The vast territories from lake Baikal in the East to Ukraine in the West harbor mostly the strains significantly different from the Far-Eastern Sophyin strain. Hybridization experiments with oligonucleotide probes specific for the Neudorffle strain showed that the strains genetically similar to the virus of central European encephalitis occurred also in Eastern Europe and Western Siberia. It is concluded that a relationship exists between genetic types of TBE virus and their geographic origin.