Contamination of commercially available fetal bovine sera with bovine viral diarrhea virus genomes: implications for the study of hepatitis C virus in cell cultures.

The establishment of cell cultures for hepatitis C virus (HCV) is important for its study as a human pathogen. However, in reported cell lines, HCV demonstrates low levels of replication detected primarily by reverse transcription-polymerase chain reaction (RT-PCR) assays. In attempts to culture HCV, an additional complication was observed. From mock-infected cultures, cDNA of appropriate size was obtained by RT-PCR with primers deduced from conserved domains of the 5' noncoding region of HCV. However, sequence analysis revealed that the cDNA was amplified from bovine viral diarrhea virus (BVDV). All of 7 bovine sera tested were contaminated with BVDV. In conclusion, most commercially available bovine sera are contaminated with BVDV and, although there is no evidence that the virus is infectious, bovine sera should be screened for this virus by RT-PCR when used in conjunction with HCV or for the development or production of vaccine.