STUDIES ON THE CYTO-PATHOLOGY OF BOVINE ADENOVIRUSES IN CALF TESTIS AND CALF KIDNEY-CELL CULTURES

The sequential development of intranuclear inclusions in calf kidney and calf testis cells infected with nine bovine adenovirus (BAV) serotypes is described. Haematoxylin and Eosin (H & E), immunofluorescent and electron microscope (EM) studies indicated two distinct subgroups of viruses. Serotypes 1, 2, 3, 7 and 9 comprised subgroup-1, while types 4, 5, 6 and 8 comprised subgroup-2. Differences were noted in the early stages of infection. With subgroup-1 viruses, irregular patches of eosinophilic material were first to appear, followed by small refractile inclusions and basophilic inclusions. In EM studies, the eosinophilic material was thought to correspond to the irregular type II inclusions, and the refractile bodies to type I inclusions. Eventually a basophilic inclusion, consisting of aggregated virus-associated inclusions and virus particles, was formed in the centre of the nucleus. With subgroup-2, the refractile inclusions were more prominent, larger, and were the first to appear. These were thought to correspond to type I inclusions, which were larger and denser than with subgroup-1. Circular basophilic bodies developing later were similar in size and distribution to type II inclusions, which with subgroup-2 viruses were seen in prominent circular or lobulated aggregates. Several other types of inclusion including tubular structures and paracrystals, which have thus far not been reported in BAV infected cells, are described. © 1979.