Prevalence of bovine immunodeficiency virus infection in cattle in Great Britain

First evidence of bovine immunodeficiency virus infection in Mexican cattle

This study set out to identify the presence of bovine immunodeficiency virus (BIV) in animals geographically located in Mexico. BIV was first discovered in the United States in a dairy cow with persistent lymphocytosis, lymphoid hyperplasia and lymphocytic encephalitis. Many studies indicate that BIV infection is globally distributed, but its presence in Mexico remains unknown. We collected 1,168 heparinized blood samples from cattle in ten states across the Mexican Republic, then separated plasma using centrifugation and tested for antibodies against BIV. We used an indirect ELISA based on the use of a synthetic peptide derived from transmembrane glycoprotein (gp45/TM). In order to identify the viral genome, we designed a synthetic gene as a PCR control, as well as a pair of oligonucleotides for amplifying a 519 bp product of the env gene which encodes the surface protein. Positive amplicons were purified and subjected to nucleotide sequencing. A total of 189 (28.94%) tested plasma samples suggest the presence of specific anti-BIV antibodies in all states studied except for Chiapas. Additionally, PCR results identified six positive cows in the states of Puebla and Coahuila. BIV in these cows was confirmed via nucleotide sequencing and in silico analysis of these samples. This is the first report of the presence of BIV in Mexican cattle.

The molecular biology of bovine immunodeficiency virus: a comparison with other lentiviruses

Bovine immunodeficiency virus (BIV) was first isolated in 1969 from a cow, R-29, with a wasting syndrome. The virus isolated induced the formation of syncytia in cell cultures and was structurally similar to maedi-visna virus. Twenty years later, it was demonstrated that the bovine R-29 isolate was indeed a lentivirus with striking similarity to the human immunodeficiency virus. Like other lentiviruses, BIV has a complex genomic structure characterized by the presence of several regulatory/accessory genes that encode proteins, some of which are involved in the regulation of virus gene expression. This manuscript aims to review biological and, more particularly, molecular aspects of BIV, with emphasis on regulatory/accessory viral genes/proteins, in comparison with those of other lentiviruses.

Sensitive and specific detection of bovine immunodeficiency virus and bovine syncytial virus by 5' Taq nuclease assays with fluorescent 3' minor groove binder-DNA probes

Sensitive assays are required to detect bovine retroviruses in donor cattle used for the in vivo preparation of Australian tick fever vaccines. 5' Taq nuclease assays using 3' minor groove binder DNA probes (TaqMan)MGB) were developed and compared to conventional PCR assays for the sensitive detection of bovine syncytial virus (BSV) and bovine immunodeficiency virus (BIV). Seven beef and dairy herds were screened to evaluate these tests. Comparative sensitivities of PCR tests were determined by testing log(10) dilutions of plasmids with inserts containing corresponding provirus sequences. Published PCR assays targeting BIV env sequences did not adequately amplify Australian BIV sequences. Pol sequences from Australian strains of BIV and BSV were used to design TaqMan MGB assays, which improved sensitivity 10-fold (BIV) and 100-fold (BSV), respectively, over conventional PCR tests. This is the first report of Australian sequences of BIV and BSV and the first 5' Taq nuclease assays described to detect these viruses. These methods could be applied to future studies requiring sensitive detection of these two bovine retroviruses.

Seroprevalence of bovine immunodeficiency virus and bovine leukemia virus in dairy and beef cattle in hokkaido

Serological survey of bovine immunodeficiency virus (BIV) and bovine leukemia virus (BLV) infection was conducted in dairy cattle from 10 different regions of Hokkaido, Japan. Among 390 cattle, 11.0% of cattle were BIV-seropositive and 3.3% were BLV-seropositive. Moreover, in two dairy farms, where bovine leukosis has been reported, prevalence of BIV infections were 6.4 and 9.1%, respectively. In contrast, among 150 beef cattle, 16.6% were BIV-seropositive while none was BLV-seropositive. Dual infections with BLV and BIV in dairy cattle were tested by using 107 BLV-seropositive sera, and 20 sera were found BIV-positive (18.7%). These results indicate that BIV infection was widespread in Hokkaido.