Electron microscope study on the development of Japanese B encephalitis virus in PS cells

An electron microscope study was performed on the ultrastructure and developmental process of the Mukai strain of Japanese B encephalitis virus propagated in vitro on porcine kidney stable cells. The virus particle of Japanese B encephalitis is hexagonal in sections and approximately 40 mμ in the maximum diameter, composed of an outer membrane, 20Å thick, viroplasm, 30 Å thick and an electron-dense nucleoid, 25 mμ in diameter. The virus particles develop by a budding process on the wall of the cytoplasmic vacuole. Thereafter, virus particles are densely packed in the vacuole usually in random arrangement and rarely in crystalline arrays. The vacuole containing virus particles gradually moves toward the cell surface and liberates the virus particles to the exterior of the cells through a narrow canaliculus. A structure suggestive of incomplete virus particles was also observed.