Characterization of vilyuisk virus as a picornavirus

The V‐1 strain of Vilyuisk virus, isolated from the cerebrospinal fluid of a chronic case of encephalomyelitis in Siberia and subsequently passaged 41 times in mice, was examined to determine its serological relationship to Theiler's murine encephalomyelitis virus (TMEV) and encephalomyocarditis (EMC) virus and some physicochemical characteristics of the virion. On the basis of virion size (28 nm), icosahedral symmetry, buoyant density (1.33 g/ml), sedimentation coefficient (150S), and capsid polypeptide profile, Vilyuisk virus appears to belong to the family Picornaviridae. Acute phase mouse antisera were used to study the antigenic relatedness of Vilyuisk, GDVII (the prototypic strain TMEV), and EMC viruses by enzyme‐linked immunosorbent assay (ELISA). The results indicate that Vilyuisk and GDVII viruses are similar but distant subtypes, and that Vilyuisk and EMC viruses are unrelated.