Homologous recombination in pestiviruses: identification of three putative novel events between different subtypes/genogroups.

Viruses from the genus Pestivirus of the family Flaviviridae have a non-segmented, single-stranded RNA genome and can cause diseases in animals from the order Artiodactyla. Homologous recombination is rarely reported in this virus family. To detect possible recombination events, all complete pestivirus genomes that are available in GenBank were screened using distinct algorithms to detect genetic conversions and incongruent phylogenies. Three putative recombinant viruses derived from recombination from different pestivirus subtypes/genogroups were detected: Bovine viral diarrhea virus 1 (BVDV-1) strain 3156, BVDV-2 strain JZ05-1 and Classical swine fever virus (CSFV) strain IND/UK/LAL-290. The present study demonstrated that the pestivirus classification cannot be based only on the analysis of one fragment of the genome because genetic conversions can lead to errors. The designation of the recombinant forms (RF) provides a more informative structure for the nomenclature of the genetic variant. The present work reinforces that homologous recombination occurs in pestivirus populations under natural replication and describes the first evidence of recombination in BVDV-2.