Formation of wesselsbron virus in BHK-21 cells

Summary

The multiplication of attenuated and virulent strains of Wesselsbron virus in BHK-21 cells have been investigated electron microscopically. In thin sections of cells infected with virulent virus and harvested at different time intervals, mesh-like structures, similar to those reported by previous workers, are observed. However, cells infected with the attenuated form of the virus do not show these structures at all, indicating that these mesh-like bodies are not a prerequisite for virus production. Cytoplasmic inclusions containing dense nucleoids and developing virus particles are reported. Mature virus particles are commonly found in cisternae of the endoplasmic reticulum in both virulent and attenuated forms of the virus. Particle measurements have yielded a diameter of 45 mμ, which is somewhat larger than measurements obtained by previous workers.

The similarity between the mesh-like structures reported in this work, the “granular virus-forming areas” reported bySoutham et al. (1964) in HBp2 cells infected with West Nile virus and the structures occurring in cells infected with yellow fever virus (Bekgold andWeibbl, 1962) may indicate a close cytopathic relationship between these group B arboviruses.