title: Comprehensive assessment of the genetics and virulence of tick-borne encephalitis virus strains isolated from patients with inapparent and clinical forms of the infection in the Russian Far East.
abstract: We analyzed the genetics and virulence of 35 strains of TBEV isolated from patients with different forms of the infection living in the southern Far East region of Russia. The results of moleculargenetics studies of the TBEV strains showed that most of the strains that cause inapparent infections form a single cluster (I) with the Oshima 5-10 strain from Japan on the phylogenetic tree. A comparison of the amino acid sequences of the viral polyproteins of the studied strains identified 17 amino acid residues distributed unevenly across the polyprotein that distinctly differed between the clusters of inapparent and virulent strains. We detected additional substitutions in the NS1 and NS5 proteins. These substitutions might influence the pathogenic potential of the strains. Using a model of inbred mice of different ages, we examined the virulence of these strains and showed the different pathogenic potentials of strains belonging to different clusters.
authors.affiliation: Institute of Epidemiology and Microbiology, Siberian Branch of Russian Academy of Medical Sciences, Vladivostok, Russian Federation. galinaleon41@gmail.com
authors.forename: Galina N
authors.initials: GN
authors.lastname: Leonova
authors.forename: Sergei I
authors.initials: SI
authors.lastname: Belikov
authors.forename: Ilya G
authors.initials: IG
authors.lastname: Kondratov
authors.forename: Ikuo
authors.initials: I
authors.lastname: Takashima
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D016000:Cluster Analysis; D004195:Disease Models, Animal; D004669:Encephalitis Viruses, Tick-Borne / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity*; D004675:Encephalitis, Tick-Borne / Q000453:epidemiology / Q000473:pathology* / Q000821:virology*; D005202:Asia, Eastern / Q000453:epidemiology; D006801:Humans; D051379:Mice; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D020815:Polyproteins / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics*; D012426:Russia / Q000453:epidemiology; D017422:Sequence Analysis, DNA; D014764:Viral Proteins / Q000235:genetics; D014774:Virulence
chemical_list: D020815:Polyproteins; D012367:RNA, Viral; D014764:Viral Proteins