GENETIC-CHARACTERIZATION OF VERGINA SEROT YPE OF TICK-BORNE ENCEPHALITIS-VIRUS AND FEATURES OF ITS PATHOLOGY

The Greek Vergina strain of tick-borne encephalitis (TBE) virus was st udied in comparison with 7 other strains by molecular hybridization of nucleis acids and by clinicomorphological markers of pathogenicity fo r monkeys and Syrian hamsters. By the genetical features the Vergina s train differed from the eastern and western TBE subtypes but was found to be similar to the strains of other subtypes of the Urals - Siberia n, east-Siberian (Aina-1448) and Central Asian antigenic variant. This group of strains hybridizen with cDNA at 65-degrees-C only in the abs ence of 50 % formamide, reacted with probe 1115 complementary to prote in E gene, with 1-3 probes complementary to the conservative region of the genome but did not react with the probes corresponding to the var iable regions of the genome. The Vergina strain is close to TBE genoty pe III. The Vergina strain was found to be virulent inducing subacute meningoencephalomyelitis which developed slowly and was accompanied by less marked morphological lesions in the cerebral cortex than those i nduced by the eastern subtype. The Vergina strain was demonstrated to persist in the brain, liver, spleen, and lymph node tissues.