SUBDIVISION OF THE PESTIVIRUS GENUS BASED ON ENVELOPE GLYCOPROTEIN E2

Conventionally, the genus Pestivirus of the family Flaviviridae has be en divided into bovine viral diarrhea virus (BVDV), classical swine fe ver virus (CSFV), and border disease virus (BDV). To date, BDV and BVD V have been isolated from different species, whereas CSFV seems to be restricted to swine. Pestiviruses are structurally and antigenically c losely related. Envelope glycoprotein E2 is the most immunogenic and m ost variable protein of pestiviruses. We cloned E2 genes of many diffe rent pestivirus strains, including those from a deer and a giraffe. Th e 52 genes were transiently expressed, characterized with monoclonal a ntibodies, sequenced, and compared. Based on these data, we can deline ate six major groups within the Pestivirus genus. Four groups correspo nd to defined genotypes, whereas the two other groups could be new gen otypes within the Pestivirus genus. One group comprises CSFV strains i solated from swine. A second group consists of BDV strains Moredun, L8 3, and X818, which have been isolated from sheep, and strain F from sw ine. A third group contains strain BD78 from sheep, strain 5250 from s wine, and strain 178003 from cattle. On the basis of E2, these viruses are very similar to BVDV strains associated with acute severe outbrea ks of bovine viral diarrhea, so-called type 2 BVDV. The fourth group c onsists of BVDV strains originating predominantly from cattle. This BV DV group can be divided into two subtypes or subgroups BVDV la and Ib: BVDV la contains viruses from the United States, such as like NADL an d Oregon, and some others, such as 150022 and 1138 from Europe. Subgro up BVDV Ib contains strain Osloss and several Dutch isolates. The fift h and sixth ''groups'' could be proposed as two new genotypes and cont ain strains Deer and Giraffe, respectively. (C) 1997 Academic Press.