Rapid characterization of new pestivirus strains by direct sequencing of PCR-amplified cDNA from the 5' noncoding region.

Reverse transcription coupled with the polymerase chain reaction (RT-PCR) was used for the rapid laboratory diagnosis of pestivirus infections. A direct DNA sequencing method was developed for the analysis of the amplified cDNA from the 5' noncoding region of the viral genome. 70 pestivirus strains were compared in this study. Sequence analysis allowed the characterization of each isolate as either classical swine fever virus (CSFV), bovine viral diarrhea virus, or border disease virus, respectively. The 48 CSFV strains could be further classified into several subgroups, which correlated either with the geographical origin or the date of the first isolation of the respective isolate.