Identification of bovine viral diarrhea virus variants — contaminants of industrial cell lines

Relevance . Contamination with bovine BVDV virus remains a threat to the quality of biological products. The most common factor of contamination is fetal bovine serum, the main factor supporting growth when cultivating cell lines, the use of which makes the risk of spreading the bovine BVDV virus almost inevitable. The aim of the study was to identify variants of bovine viral diarrhea virus, which are contaminants of production cell lines. Methods . The cell lines MDBK, BHK-21/13-02, PK-15, Vero and the production strains of the bovine HD virus NADL, VK-1 were used To amplify the target regions of the viral genome, oligonucleotide primers flanking the highly conserved untranslated region 5`UTR with a length of 289 bp were used. Comparative analysis of nucleotide sequences determined by sequencing was carried out using standard methods of molecular phylogenetics. Results. The fact of chronic infection with non-cytopathogenic bovine BVDV virus was confirmed in relation to the cell lines MDBK, BHK-21/13-02 and PK-15. Based on sequencing results, the contaminating virus variants were identified as representatives of subgenotype 1a. Phylogenetic analysis revealed their significant similarity between themselves and a number of strains isolated from persistently infected llamas, alpacas and roe deer with an identity of 96.8–99.2%. The presented data demonstrate the need for ongoing such screenings, which will improve the quality of technological raw materials used for the production of biological products, as well as improve existing means of serological diagnosis of infections caused by representatives of the Pestivirus genus.