A RT-PCR assay for the rapid recognition of border disease virus

A reverse transcription - polymerase chain reaction (RT-PCR) method was dev eloped for the specific detection of border disease virus (BDV), using the primers PBD1 and PBD2 flanking a 225 bp DNA fragment, selected from the 5'n oncoding region of the pestivirus genome. In tests on 70 pestiviruses it wa s shown to be BDV-specific. A closed, one.-tube nested RT-PCR method employ ing general pestivirus outer primers (324 and 326), and the same BDV-specif ic inner primers (PBD1 and PBD2) in conjunction with a BDV-specific fluorog enic TaqMan probe also detected only BDV and was more sensitive. BDV-specif ic RT-PCR was used in combination with a PCR specific for bovine vir al dia rrhoea virus type 2 (BVDV2) to ascertain whether virus stocks contained mix tures of BDV and BVDV2. It was shown that the ovine pestivirus strains 1753 75 and 59386 were originally BDV, but after subculture had become contamina ted with BVDV2. This explains a previously reported discrepancy in the gene tic typing of 59386. Although the BDV-specific RT-PCR can also detect BDV i n clinical samples, the assay is likely to be most useful for the rapid typ ing of laboratory pestivirus strains.