Genetic typing of bovine viral diarrhoea virus (BVDV) by restriction fragment length polymorphism (RFLP) and identification of a new subtype in Poland

Restriction fragment length polymorphism (RFLP) analysis was developed for genetic ty ping of Polish strains of bovine viral diarrhoea virus (BVDV). The method was applied using 60 BVDV isolates, which included BVDV genotype 1, subtypes a, b, d, e, f, and g, and genotype 2a. RT-PCR products of the 5'untranslated region (5'UTR) were digested using three enzymes. Restriction patterns classified the strains into seven groups, each with a specific and different pattern from other subty pes. These findings were confirmed by nucleotide sequencing and phylogenetic analysis. The results suggest that RFLP analysis is a simple, reliable, and fast genotyping method for BVDV strains in comparison with sequencing. This method can distinguish six subtypes of BVDV-1 including a new subtype 1e, identified exclusively by this method, and it allows differentiation of BVDV-1 from BVDV-2 genotype.