Isolation and identification of Muscovy duck reovirus

Seven strains of reovirus were isolated from the liver and spleen with lots of gray white local necroses (“liver white spots”) of Muscovy duck. The virion showed spherical, no envelope, having double deck capsids, with outer capsid of 75 nm in diameter, with inner capsid of 50 nm in diameter; inagglutable red cells of chicken, duck, ribbit and gumea, it had certain antigen correlation with avian reovirus by AGP. The isolated B3 could produce some cytopathogenic effects such as the rounded cells, the fusion cells, polykaryocytes and megacells with inclusions in cytoplasm on the Muscovy duck or chicken embryo fibroblast cells. The mortality rate of the one day old sensitive Muscovy dusk inoculated with the isolated virus was up to 100%, and the clinical signs and the pathologies of died Muscovy duck were identical with those of field cases, and the isolated strain was recovered again. The results demonstrated that the pathogen of being epidemic liver “white spots” disease of domestic Muscovy duck was Muscovy duck reovirus, which was a member of the family Reoviridae, genus Orthoreovirus .