Giraffe strain of pestivirus: its taxonomic status based on the 5'-untranslated region

The 5'-untranslated region (5'-UTR) of the 'Giraffe' strain of pestivirus was sequenced for comparison with those of other pestiviruses from cattle, sheep, goats, and swine. A phylogenetic tree constructed with these strains suggested that the 'Giraffe' strain was allocated to a new taxon. This observation was also confirmed by a newly proposed method based on palindromic nucleotide substitutions (PNS) at the three variable regions in the 5'-UTR. Other reported pestivirus strains isolated from deer were assigned as bovine viral disease virus (BVDV)-1 according to the PNS as well as phylogenetic analysis, suggesting that BVDV-1 strains can cross-infect deer as well as cattle, sheep, goats, and swine, and that wild deer may serve as a reservoir of BVDV-1. We also identified the genovar of a deer isolate, SH9/11, as BVDV-1c by the PNS method.