Persistence of Adenovirus 5 in guinea pigs

One intracardiac inoculation of adenovirus 5 in guinea pigs leads to virus persistence in different organs, viz., 5 days in lungs and liver, 14 days in blood and lymph nodes, and 56 days or more in the spleen. After cultivation of tissue cells for 1 week, virus was recovered from blood, lymph nodes, or spleen lymphocytes, but virus could be detected directly in cells only when organs were removed within 48 h of inoculation. To determine how the virus persisted in low concentrations and as a latent infection, spleens were primarily selected for study by three techniques: homogenization of spleens, suspended Maitland fragment cultures, and in vitro cultivation of spleen cells. The last procedure showed virus in fibroblast-like cells (probably macrophages or reticuloendothelial cells) for 56 days after infection of guinea pigs. With other methods, the virus was found only within the first 2 days after inoculation.

Isolation and characterization of an Avian adenovirus-associated virus

An 18- to 20-nm virus particle was isolated from the Olson strain of quail bronchitis, an avian adenovirus. On density gradient separation the small virions were primarily found at densities of 1.39 and 1.42 g/cm(3). The majority of the infectious particles were at the heavier density. The virus had a hexagonal outline and contained single-stranded deoxyribonucleic acid. It was resistant to heating at 56 C for more than an hour and was not inactivated by treatment with chloroform or low pH. Purified virus did not agglutinate erythrocytes of various avian and mammalian species. Replication of the small particles occurred either in chicken embryos or in cultures of embryo kidney cells coinfected with an adenovirus helper. Antigenically the virus was distinct from the adeno-associated viruses types 1, 2, 3, and 4. The virus is the avian equivalent of the adeno-associated viruses of primates and lower animals.