Identification and characterization of pestiviruses isolated from individual fetal bovine serum samples originated in Rio Grande do Sul state, Brazil

Abstract

ABSTRACT: The identification of diversity of bovine pestiviruses circulating in the field is fundamental for continuous evaluation of diagnostic tests and vaccine composition. In this article we performed the genetic and antigenic characterization of twelve bovine pestiviruses isolated in the western region of Rio Grande do Sul, Brazil. The viruses were isolated from sera of bovine fetuses or from animals with clinical presentations suggestive of pestivirus infection. Genetic characterization by sequencing and phylogenetic analysis of the 5’UTR region of the viral genome allowed for the identification of bovine viral diarrhea virus (BVDV-1a, 4/12, 33.3%), BVDV-1b (6/12, 50%) and BVDV-2 (2/12, 16.7%). The reactivity of the isolates with a panel of monoclonal antibodies raised against envelope proteins (Erns, E1 and E2) demonstrated a high antigenic variability among isolates. Thus, the active circulation of bovine pestivirus infection, with high genetic and antigenic variability, in cattle on the western border of RS was confirmed, demonstrating the importance of continuous characterization of the pestiviruses circulating in the cattle herds to keep the diagnostic and control measures up to date.