Replication of the bovine immunodeficiency-like virus in diploid and aneuploid cells: permanent, latent and virus-productive infections in vitro.

Bovine immunodeficiency-like virus (BIV) is an infectious and leukotropic retrovirus, the sole lentivirus candidate which has been isolated from cattle. Although BIV has recently been shown to be related to the human immunodeficiency virus, there is very limited information on the replication and the pathogenesis of BIV. It is reported here that BIV can permanently infect diploid and aneuploid cells from four different species: bovine, canine, ferret and ovine.

Characterization of an atypical biotype of Brucella abortus.

Brucella abortus strains were isolated from bovine tissue and milk samples from seven Ontario herds. The isolates were characterized by colonial morphology, requirement of CO2 for growth, lysis by Tbilisi phage, biochemical tests and agglutination in monospecific sera. They resembled B.

A comparison of the bovine leukemia and bovine syncytial virus status in utero-tubal cells recovered from fluids used to flush the uterus and oviducts of BLV-infected, superovulated cattle.

Twenty-four cell lines were established from uterine-oviductal flush fluid (UOFF) cells from 20 bovine leukosis virus (BLV)-infected embryo-donor cows and 4 BLV-free control cows harvested by the Ficoll-gradient technique. Similar epithelial-like and fibroblast-like cells were observed in the primary cultures of UOFF from both groups. BLV-antigens were not detected with direct immunofluorescence test in any of the cell-lines from the 20 positive BLV-cows but a positive reaction was observed with the competitive radioimmunoassay in one cell line only.

A comparison of five serological tests for bovine brucellosis.

Five serological assays: the buffered plate antigen test, the standard tube agglutination test, the complement fixation test, the hemolysis-in-gel test and the indirect enzyme immunoassay were diagnostically evaluated. Test data consisted of results from 1208 cattle in brucellosis-free herds, 1578 cattle in reactor herds of unknown infection status and 174 cattle from which Brucella abortus had been cultured. The complement fixation test had the highest specificity in both nonvaccinated and vaccinated cattle.

The persistent infection of a canine thymus cell line by equine infectious anaemia virus and preliminary data on the production of viral antigens.

Equine infectious anaemia virus (EIAV) was adapted to the Cf2Th cell line, a heterologous malignant line from canine thymus. A persistent infection was monitored for 100 serial passages by demonstrating the presence of virus and viral antigens at each 10th passage by electron-microscopy, immunodiffusion and immunofluorescence. Chromosome analysis of EIAV-infected cells indicated they had a karyotype resembling the control cells of similar passage history.