PCR - A LOOK BEHIND THE SCENES AT BOVINE VIRAL DIARRHEA VIRUS

As indicated by their nucleotide sequences bovine viral diarrhea virus es (BVD-virus) are genetically quite heterogenous. Despite differences in the nucleotide sequence in the NS3 region, we found that the deriv ed amino acid sequence of all viral strains analyzed was identical and differed from that of classical swine fever viruses, thus allowing di fferentiation between bovine and porcine pestiviruses. Remarkably, the BVD vira!strains were isolated over a time period of some 40 years in Europe, North America and New Zealand. The nucleotide sequence of the 5' untranslated genome region of a BVD virus recently isolated in Swi tzerland from a calf with hemorrhagic syndrome differs from that of BV D viruses causing similar symptoms in a large epidemic outbreak in Nor th America.