REOVIRUS GROWTH INHIBITION BY ROTAVIRUS FOLLOWING COINFECTION

Interference between the two members of reoviridae family, which multiply inside the cytoplasm of the host cell, was investigated. Monkey kidney cells (BSC-1) were coinfected with reo and rota viruses and the amount of virus produced was determined by TCID50 and Fluorescent Focusing Assay (FFA). Upon coinfection the growth of reovirus was reduced considerably in presence of rotavirus. Electron microscope examination of viruses extracted from mixed infected cells revealed that only rotavirus particles were present. This observation was confirmed by examining thin section of coinfected cells in which only cytoplasmic rotavirus like particles were visualized. Interference between rotavirus and reovirus was not at the level of adsorption and receptor attachment competition. Analysis of viral RNA extracted from the coinfected cells revealed that RNA genomes of both viruses were synthesized but after the first passage only rotavirus RNA was present in the infected cells. Similarly viral proteins of both viruses were produced in coinfected cells as was shown by polyacrylamide gel electrophoresis, followed by immunoblotting and by the immunofluorescence staining. Since there was no inhibition of viral macromolecular synthesis in mixed infected cells it was concluded that inhibition of reovirus maturation in presence of rotavirus was probably at the level of virus assembly.