Genetic diversity of pestiviruses: Identification of novel groups and implications for classification

The complete N-pro coding sequences were determined for 16 pestiviruses iso lated from cattle, pig, and several wild ruminant species including reindee r, bison, deer, and bongo. Phylogenetic analysis enabled the segregation of pestiviruses into the established species bovine viral diarrhea virus-1 (B VDV-1), BVDV-2, border disease virus (BDV), and classical swine fever virus (CSN). For BVDV-1 five distinct subgroups were identified, while BVDV-2, B DV, and CSN were each subdivided into two subgroups. The virus isolates fro m bongo and deer as well as one porcine virus isolate belong to BVDV-1. Int erestingly, the isolates from reindeer and bison are distinct from the esta blished pestivirus species. The N-pro sequences from these two viruses are more similar to BDV than to the other pestivirus species. Calculation of th e pairwise evolutionary distances allowed a clear separation of the categor ies species, subgroup, and isolate only when the reindeer/bison viruses wer e considered as members of an additional pestivirus species. Furthermore, t he entire E2 coding sequences of a representative set of virus isolates cov ering all recognized species and subgroups were studied. Segregation of pes tiviruses based on the E2 region was identical with that obtained with the N-pro sequences. (C) 1999 Academic Press.