Isolates of bovine viral diarrhoea virus (BVDV) collected in Germany w
ere examined for their genomic heterogeneity in sequences from the 5'u
ntranslated region (UTR) of the viral genome. Polymerase chain reactio
n (PCR) tests based on the 5'UTR and the region coding for the NS2-3/4
A polypeptide were used to differentiate between BVDV I and BVDV II ge
notypes. Eleven out of 96 BVDV-isolates were identified as BVDV II. Vi
rus neutralization tests with BVDV I-or II-specific antisera raised in
cattle were done. The mean titers were reduced by 7.2-fold (BVDV I-an
tiserum versus type II-isolates) or 35-fold (BVDV II-antiserum versus
type I-isolates) when using the respective heterologous virus.