Some Properties of Avian Adenoviruses Isolated from Chickens with Inclusion Body Hepatitis in Japan

SUMMARY Oubreaks of inclusion body hepatitis were observed in broiler chickens on a poultry farm during 3 years. Avian adenovirus-like agents were isolated during these years from livers of diseased chickens. Round-cell-type cytopathogenic effect and intranuclear inclusion bodies were produced in chicken kidney cell cultures inoculated with these agents. Properties of the agents were as follows: resistant to ether, chloroform, sodium deoxycholate, trypsin, heating at 50 C, and pH 3.0; sensitive to 5-iodo-deoxyuridine; and pathogenic to chicken embryos. From these properties and ultrastructural findings of the agents, these were identified as avian adenovirus. Day-old commercial chicks were insusceptible to these viruses. Maternal antibody levels in commercial chicks were considerable. Surveys for neutralizing index to the virus were performed on chickens in the field, and all sera tested were positive. Electron-microscope examination showed that these viruses contained avian-adenovirus