Detecção molecular do vírus da imunodeficiência bovina (BIV) em rebanhos bovinos do sudoeste do Maranhão

Abstract

The bovine viral immunodeficiency is a chronic and progressive disease that mainly affects cattle, inducing signs of persistent leukocytosis, lymphadenopathy, progressive weight loss. It may be associated with decreased milk production and lymphocyte response. Therefore, the objective of this study was to verify the occurrence of the Bovine Immunodeficiency Virus (BIV) in the bovine herd of cattle of the Southwest of Maranhão. In order to verify the occurrence of BIV in the herd of cattle, the proviral DNA was detected in 550 bovine blood samples from 31 properties by means of the semi-nested polymerase chain reaction (PCR-SN) using oligonucleotide primers specific for the pol region genome of the virus. Of the 550 samples tested on SN-PCR for BIV, 19 (3,4%) were positive. The amplified sequences were confirmed by nucleotide sequencing. The similarity of the nucleotide sequence of the samples isolated with the Washington isolate was 96%. Statistically significant risk factors associated with the dissemination of BIV were considered in this region: use of milk and dairy products to feed other animals, purchase of animals for reproduction and presence of flooded areas on the property. This study reveals the first detection of the presence of BIV in the Maranhão herd of cattle, alerting the possibility of the virus to act as a risk factor for the of the bovine populations of the region.