Geographical and Tick-Dependent Distribution of Flavi-Like Alongshan and Yanggou Tick Viruses in Russia

The genus <i>Flavivirus</i> includes related, unclassified segmented flavi-like viruses, two segments of which have homology with flavivirus RNA-dependent RNA polymerase NS5 and RNA helicase-protease NS3. This group includes such viruses as Jingmen tick virus, Alongshan virus, Yanggou tick virus and others. We detected the Yanggou tick virus in <i>Dermacentor nuttalli</i> and <i>Dermacentor marginatus</i> ticks in two neighbouring regions of Russia. The virus prevalence ranged from 0.5% to 8.0%. We detected RNA of the Alongshan virus in 44 individuals or pools of various tick species in eight regions of Russia. The virus prevalence ranged from 0.6% to 7.8%. We demonstrated the successful replication of the Yanggou tick virus and Alongshan virus in IRE/CTVM19 and HAE/CTVM8 tick cell lines without a cytopathic effect. According to the phylogenetic analysis, we divided the Alongshan virus into two groups: an <i>Ixodes persulcatus</i> group and an <i>Ixodes ricinus</i> group. In addition, the <i>I. persulcatus</i> group can be divided into European and Asian subgroups. We found amino acid signatures specific to the <i>I. ricinus</i> and <i>I. persulcatus</i> groups and also distinguished between the European and Asian subgroups of the <i>I. persulcatus</i> group.