Recall phenomenon induced with ovine adenoviruses. Brief report

Bovine adenovirus type 10: properties of viruses isolated from cases of bovine haemorrhagic enterocolitis

The isolation, serological classification and growth properties of adenoviruses isolated from fatal cases of haemorrhagic enterocolitis in calves are described. Four viruses, from different submissions, were isolated in cultures of calf testis cells and were identified as adenoviruses by electron microscopy. The four isolates were serologically identical and were classified as bovine adenovirus type 10 in cross-neutralisation tests with other bovine, ovine and porcine adenovirus species. Their growth in the nucleus of infected cells was accompanied by the production of typical adenovirus-associated inclusions. A serological survey to determine the incidence of infection with the virus in cattle in Northern Ireland demonstrated the presence of low levels of neutralising antibodies in 55 per cent of cattle over two years old, although only 8 per cent were positive at a 1/500 dilution of serum.

DNA structure, and hemagglutination properties of bovine adenovirus type 2 strains which bypass species specificity

Bovine adenovirus type 2 (Ad bos 2) strains were examined which had been isolated during natural outbreaks among calves, and lambs in Hungary [Belák, S., Pálfi, V.: Arch. ges. Virusforsch. 46,366-369 (1974)]. Differences were detected in hemagglutination properties, and in the restriction site maps of the DNA, which seem to be sufficient to group isolates of Ad bos 2 into two subtypes (subspecies). Some of the strains, recovered from cattle including prototype strain No. 19 are suggested to be separated as subtype A. These viruses hemagglutinate bovine red blood cells, and the physical map of the DNA is similar to, or identical with that of the prototype strain. Virus strains tentatively grouped into subtype B are pathogenic for both cattle, and sheep under natural conditions. Members of subtype B hemagglutinate only rat erythrocytes, and characteristic differences may be detected with BamHI, EcoRI, KpnI, and SalI restriction endonucleases in comparison to the physical maps of the DNA of prototype virus. The genome size of all isolates tested was measured to be of Mr 19.5 to 20.0 X 10(6), similar to Ad ovi 1, 4, and Ad bos 4, and 6. All isolates of subtype B characteristics were shown to encapsidate heterogeneous genome populations which could be distinguished from those of subtype A by the presence of specific restriction endonuclease cleavage fragments with molar ratios of less than 1.0.