|CROSSLEY, BEATE - University Of California, Davis|
|MOSENA, ANA - Universidade Federal Do Rio Grande Do Norte|
|KILLIAN, MARY - Animal And Plant Health Inspection Service (APHIS)|
Submitted to: Virology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/23/2019
Publication Date: 9/1/2019
Citation: Neill, J.D., Crossley, B.M., Mosena, A.C., Ridpath, J.F., Bayles, D.O., Killian, M.L., Falkenberg, S.M. 2019. Genomic and antigenic characterization of a cytopathic bovine viral diarrhea virus 1i isolated in the United States. Virology. 535:279-282. https://doi.org/10.1016/j.virol.2019.07.020.
Interpretive Summary: Bovine viral diarrhea virus (BVDV) is a common pathogen of cattle that causes mild to very severe disease in infected cattle. The BVDV1 species has been divided into 21 subgroups based on virus sequencing, but only BVDV1a and BVDV1b are present in the U.S. Additionally, BVDV can be either cytopathic or noncytopathic, where cytopathic viruses kill cultured cells and noncytopathic do not. In this study, a seven year old cow was found dead and submitted to a diagnostic laboratory to determine cause of death. BVDV was detected in all tissues. From these tissues a cytopathic BVDV was isolated. Preliminary work showed that this virus was neither BVDV1a or BVDV1b. Following sequencing of the entire virus, it was found to have sequences known to make BVDV cytopathic. This virus was also the first cytopathic BVDV1 that was neither a 1a or 1b virus. This virus was found to belong to the BVDV1i subgroup that had only been reported in Europe and Brazil. Laboratory tests using antibodies against U.S. vaccine viruses showed that there is only a small amount of recognition of this new virus. This may indicate that the vaccines currently used in the U.S. may not protect well against new viruses should they appear in domestic cattle herds.
Technical Abstract: Bovine viral diarrhea viruses (BVDV) are a common global viral pathogen of ruminants. Considerable genetic variability was found amongst BVDV1 isolates, with least 21 subgenotypes being described. In the United States, BVDV1a and 1b are the only subgenotypes described to date. Here, the genomic sequence of CA2005, a cytopathic BVDV1, was determined. This virus, isolated in California, did not segregate into either BVDV1a or 1b subgenotypes. BLAST analysis showed CA2005 was most closely related to BVDV1i isolates. CA2005 was also the first cytopathic BVDV1i and one of few non-1a, non-1b cytopathic viruses reported. The genomic sequence was 15,752 nucleotides in length. Cytopathogenicity was conferred by duplication of the NS3 protein with a small ubiquitin B insertion at the border of the NS2/NS3 proteins. Virus neutralization assays using antisera against BVDV1a vaccine viruses revealed variable neutralization, suggesting modified live vaccines may not be totally protective against CA2005 and similar viruses.