In vitro isolation, propagation, and characterization of duck hepatitis virus type III

The in vitro isolation, propagation, and characterization of duck hepatitis virus Type III (DHV-III), is described. This virus, which is serologically distinct from the classical (Type I) DHV, replicated in liver and kidney cell cultures of duck origin. Replication was limited in chicken and quail kidney and duck embryo fibroblast cultures. It did not replicate in a variety of other cell cultures of avian or mammalian origin. The virus was grown successfully in embryonating eggs of ducks, but not of chickens. DHV-III passed through a 50-nm membrane filter, was stable at pH 3.0 and resisted treatment with 5% chloroform. Virus growth was not inhibited by treatment with 5-iodo-2-deoxyuridine. Electron-microscope examination revealed crystalline arrays in the cytoplasm; virus particles had cubic symmetry, and were about 30 nm in diameter. By these properties, this virus can be classified as a member of the picornavirus group.