Detection and identification of the atypical bovine pestiviruses in commercial foetal bovine serum batches

Abstract

The recently emerging atypical bovine pestiviruses have been detected in commercial foetal bovine serum (FBS) of mainly South American origin so far. It is unclear how widely the viruses are presented in commercial FBS of different geographic origins. To further investigate the possible pestivirus contamination of commercially available FBS batches, 33 batches of FBS were obtained from ten suppliers and analysed in this study for the presence of both the recognised and the atypical bovine pestiviruses. All 33 batches of FBS were positive by real-time RT-PCR assays for at least one species of bovine pestiviruses. According to the certificate of analysis that the suppliers claimed for each batch of FBS, BVDV-1 was detected in all 11 countries and BVDV-2 was detected exclusively in the America Continent. The atypical pestiviruses were detected in 13 batches claimed to originate from five countries. Analysis of partial 5'UTR sequences showed a high similarity among these atypical bovine pestiviruses. This study has demonstrated, for the first time that commercial FBS batches of different geographic origins are contaminated not only with the recognised species BVDV-1 and BVDV-2, but also with the emerging atypical bovine pestiviruses.

Figure 1. Neighbor-Joining analysis of a 249-bp fragment of the 5′UTR sequences under Kimura 3-parameter model.

The sequences are labelled with sample ID (-number of clone)/country or region of origin. AU, Australia; BR, Brazil; CA, Canada; CO, Colombia; DK, Denmark; DR, Dominican Republic; EU, European Union; FR, France; MX, Mexico; NI, not identified by supplier; NZ, New Zealand; SA, South American; US, USA; ZA, South Africa. Numbers are percentage of bootstrap values (1000 replicates) for major clades. Bar indicates changes per site. The GenBank accession numbers for reference strains are DQ075210, NC_001461, U97481, AF026781, AB359927, AF049221, AY363096 and FJ493479 for BVDV-1, AY763053 and NC_002032 for BVDV-2, and NC_012812 for BVDV-3.