Electron microscopic study of the morphogenesis of echovirus 23

The ultrastructural features of the cytopathology which accompanies the replication of echovirus 23 in African green monkey kidney cells is reported. Infected cells first undergo a marked clumping and margination of nuclear chromatin, followed by degenerative changes in the membranous organells of the cell. Affected structures include the nuclear membrane, mitochondrial cristae, and smooth and rough endoplasmic reticulum. Virus particles are first evident at the periphery of membrane-limited vesicles located in the perinuclear area. No well-defined viral inclusions or semicrystalline arrays of virus particles are seen. Virus appears to exit from the cells by fragmentation of the plasma membrane.