Abstract
Bovine viral diarrhea viruses (BVDV), segregated in BVDV-1 and BVDV-2 species, lead to substantial economic losses to the cattle industry worldwide. It has been hypothesized that there could be differences in level of replication, pathogenesis and tissue tropism between BVDV-1 and BVDV-2 strains. Thus, this study developed an in vitro method to evaluate virus competition between BVDV-1 and BVDV-2 strains. To this end the competitive dynamics of BVDV-1a, BVDV-1b, and BVDV-2a strains in cell cultures was evaluated by a PrimeFlow RNA assay. Similar results were observed in this study, as was observed in an earlier in vivo transmission study. Competitive exclusion was observed as the BVDV-2a strains dominated and excluded the BVDV-1a and BVDV-1b strains. The in vitro model developed can be used to identify viral variations that result in differences in frequency of subgenotypes detected in the field, vaccine failure, pathogenesis, and strain dependent variation in immune responses.
Highlights
Ruminant pestiviruses are globally-distributed pathogens responsible for a broad range of clinical presentations, which range from mild to severe and may affect the respiratory, digestive and/or the reproductive system (MacLachlan and Dubovi, 2011)
Bovine viral diarrhea virus-1 (BVDV-1) and Bovine viral diarrhea viruses (BVDV)-2 are grouped in two different species, Pestivirus A and B, respectively, with multiple subgenotypes and belong to the genus Pestivirus, family Flaviviridae
For the in vitro competition assay the representative strain of each subgenotype that resulted in the greatest number of PI animals, PI34 (BVDV-1a), PI285 (BVDV-1b), PI28 (BVDV-2a) were selected
Summary
Ruminant pestiviruses are globally-distributed pathogens responsible for a broad range of clinical presentations, which range from mild to severe and may affect the respiratory, digestive and/or the reproductive system (MacLachlan and Dubovi, 2011). Bovine viral diarrhea virus-1 (BVDV-1) and BVDV-2 are grouped in two different species, Pestivirus A and B, respectively, with multiple subgenotypes and belong to the genus Pestivirus, family Flaviviridae. The viral genome is approximately 12.3 Kb long and contains a unique open reading (ORF) frame that is flanked by 5′ and 3’ untranslated regions (UTRs). Clinical presentations include a wide spectrum of virulence including acute and persistent infections invariably accompanied by immunosuppressive effects. These viruses are frequent contaminants of biological products and vaccines (Barkema et al, 2001; Fulton et al, 2003; Palomares et al, 2013; Schweizer and Peterhans, 2014; Kelling et al, 2002). Current licensed vaccines in the US only contain BVDV-1a and BVDV-2a strains (Fulton, 2015), but the most recent surveillance would suggest that BVDV-1b strains are the most prevalent in the US (Fulton et al, 2006; Workman et al, 2016)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
