Antibody Tests and Isolation of the Cytopathogenic Bovine Viral Diarrhea Virus

Abstract

Antibody tests and isolation of the bovine diarrhea virus (BVDV) have been performed on primary bovine fetal muscular-cell cultures. The cytopathogenic effect (CPE) was the index in the case of cytopathogenic viruses. The interference method was employed in dealing with non-cytopathogenic types, which demonstrate no CPE. In this study, we made use of the characteristic of bovine kidney cell line (MDBK-SY) to be induced the CPE by both CP and NCP viruses and examined the possibility of a new BVDV assay method. This new assay was used in isolating 4 BVDVs from field specimens. Previous assays had identified one of these strains as CP BVDV and the other as NCP BVDV. Both previous assays and the new assay were used to determine the neutralization antibody titers to Nose, No.12, and KS86-1 NCP in serum specimens. The neutralization antibody titers to those strains determined by the new assay correlated significantly with those determined by previous assays. These results suggest that the new assay established in this study is a useful system for BVDV investigation.