Bovine Adenovirus

Two adenovirus strains were isolated in calf testicle cell cultures from blood specimens of cattle in Japan. This is the first isolation of bovine adenovirus reported in Japan. The isolates were antigenically similar to each other and distinct from the hitherto described serotypes 1, 2 and 3 of bovine adenovirus. Unfortunately, bovine adenovirus types 4 and 5 were not available for comparison, and hence, until the matter is settled, the virus will be called “Bovine adenovirus type Nagano”. Nagano virus was identified as adenovirus on the bases of the inhibitory effect of 5‐iodo‐2′‐deoxyuridine on virus replication, ether‐resistance, effect of temperature and pH on infectivity, and fine structure of the virus particle. The virus grew and formed intranuclear inclusion bodies, a characteristic of adenovirus, in bovine testicle cells but not in bovine kidney cells. The virus agglutinated rat erythrocytes very poorly, but not sheep, goat, cattle, horse, guinea pig, hamster, chicken, and mouse cells. The virus produced adenovirus group‐specific antigen in cell cultures. Sero‐negative calves were readily infected with the virus by the intravenous, subcutaneous, oral or intranasal routes of inoculation. The infected animals produced antibodies and showed a mild clinical reaction comprised of rhinorrhea, diarrhea and a degree of pyrexia; low‐titered viremia of short duration and leukopenia were also observed. A serologic survey indicated wide‐spread dissemination of the virus among Japanese cattle, but further studies are needed to determine the etiologic significance of the virus in the natural disease in cattle.