SummaryA bovine adenovirus was isolated in cell cultures of calf testis from the shoulder lymph node of a leukotic cow. Biological and physico-chemical properties of the isolate are described.Serological differentiation revealed a close relationship with bovine adenovirus type 6 (RoccD~zs). In neutralization tests the virus was not related with human, simian, fowl, geese, dog, porcine and bovine (serotype 1--5) adenoviruses tested.Calves infected with the virus developed undulating fever, acute rhinitis, conjunctivitis and swelling of lymph nodes.Up to recently 5 different serotypes of bovine adenoviruses were known (1,2,3,6,7). These viruses were isolated fi'om the respiratory tract (2, 3) and from feces (6, 7) of calves. TANAKA and coworkers (11) and I•ABA et al. (5) propagated bovine adenovirus type 4 and another isolate to be differentiated (8) from blood of calves with rhinitis, diarrhea and fever. RONDtIUIS (9) and SoHoPov et al. (10) found contaminating bovine adenoviruses in cell cultures from calf kidney and testis. The latter strains were not related to serotypes 1--5, and were independently registered as serotype 6. BA~THA (personal communication) isolated an adenovirus from cattle (strain Misk 67) which also does not react with bovine serotypes 1--5.About one year ago we successfully propagated a cytopathogenic agent (strain 1116) from the shoulder lymph node of a cow with leukosis. Biological and physico-chemical properties of this isolate allowed its classification as adenovirus.The virus was isolated by continuous passages of lymph node material in calf testicular cell cultures. After 4 blind passages a cytopathic effect (CPE) was noticed, which began 2--3 days post infection. The CPE was characterized by granulation, rounding and subsequent lysis of cells. Infectivity titers of 104"7~ KIDs0/ml were recorded for cell cultures after adaptation.Intranuclear, multiple basophilic inclusion bodies were observed in hematoxylin-eosin stained infected cell cultures before CPE occurred.
272A. MAYR, G. WIZm~AN~, B. BIBRACK, and P. A. BACH~ANN:The isolated virus was stable against treatment with chloroform and showed the typical morphology of adenovirus particles in the electron microscope. Size of the particles varied between 75 and 80 m~z.The virus isolate 1116 shared a common group specific complement fixing antigen with bovine (serotype 1--4) and porcine (serotype 4) adenoviruses.In neutralization tests it did not show any serological relationship with human adenovirus types 1--31 (types 23 and 25 were not tested), simian adenoviruses (types SV 1,11, 15, 17, 33, 34, 36), with CELO virus of fowl, adenovirus of geese, canine hepatitis virus (Hec), the adenovirus strain A 26/61 from dogs, and serotypes I--4 of proeine adenoviruses.Furthermore it was not neutralized by specific hyperimmune sera against bovine adenovirus serotypes 1--51.From the neutralization tests a close relationship resulted between serotypes 6 of bovine adenoviruses of gOSDgUis (9) and isolate 1116, using type 6 immune serum and isolate 1...