Phylogenetic analysis of small ruminant lentiviruses from Northern Brazil

Caprine Arthritis Encephalitis virus (CAEV) and Visna/maedi virus (VISNA), are considered to be genetically distinct but antigenically related pathogens of goats and sheep. In this study, one flock of 250 goats was screened using Agar-gel Immunodiffusion (AGID), and the level of seroprevalence observed was 11 animals (4.4%) of positive tested serum. Four goats positive to AGID were analyzed using a Polymerase Chain Reaction (PCR), which amplifies part of the gag gene. All the animals were found to be positive. The nucleotide sequences of gag gene were determined from four BR/CNPC lentivirus isolates from naturally infected goats. The four gag gene sequences BR/CNPC small ruminant lentivirus (SRLV) were compared to GenBank, and the results demonstrated that these sequences were more related to the caprine rather than the ovine strains. Further phylogenetic analysis of the proviral gag sequences showed that they constituted subtype B1 of the CAEV group. The analyses of the sequences also showed that the viruses were genetically stable.