Skip to main content
ARS Home » Plains Area » Clay Center, Nebraska » U.S. Meat Animal Research Center » Genetics, Breeding, and Animal Health Research » Research » Publications at this Location » Publication #315843

Research Project: Genetic and Biological Determinants Of Respiratory Diseases Of Ruminants

Location: Genetics, Breeding, and Animal Health Research

Title: Resolving bovine viral diarrhea virus subtypes from persistently infected US beef calves with complete genome sequence

Author
item Workman, Aspen
item Heaton, Michael - Mike
item Harhay, Gregory
item Smith, Timothy - Tim
item Grotelueschen, Dale - University Of Nebraska
item Sjeklocha, David - Cattle Empire, Llc
item Brodersen, Bruce - University Of Nebraska
item Petersen, Jessica - University Of Nebraska
item Chitko Mckown, Carol

Submitted to: Journal of Veterinary Diagnostic Investigation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/17/2016
Publication Date: 8/30/2016
Citation: Workman, A.M., Heaton, M.P., Harhay, G.P., Smith, T.P.L., Grotelueschen, D.M., Sjeklocha, D.B., Brodersen, B.W., Petersen, J.L., Chitko-McKown, C.G. 2016. Resolving bovine viral diarrhea virus subtypes from persistently infected U.S. beef calves with complete genome sequence. Journal of Veterinary Diagnostic Investigation. 28(5):519-528.

Interpretive Summary: Bovine viral diarrhea virus (BVDV) is an important pathogen of cattle that can lead to respiratory disease, enteritis, immune dysfunction, and can predispose the animal to secondary infections. BVDV is classified in 2 species, BVDV-1 and BVDV-2, each of which contains distinct subtypes. To effectively control BVDV, it is important to know which subtypes of the virus are circulating and how their prevalence is changing over time. Currently, three major subtypes of BVDV are circulating in the United States: BVDV-1a, 1b, and 2a. In addition, BVDV-2b has been isolated from a single animal with a fatal case of respiratory disease in Oklahoma. This observation highlights the need for continual surveillance to detect potential emerging subtypes of BVDV in the U.S. To this end, this study sought to estimate the current prevalence of BVDV subtypes by sampling persistently infected (PI) beef calves in the central U.S. Analysis of 119 viral strains of BVDV from infected cattle on a feedyard in Kansas revealed that a majority (83%) of the strains belonged to genotype 1b, and the remaining strains were distributed approximately equally between genotypes 1a (9%) and 2a (8%). This study did not detect BVDV-2b or other previously unreported subtypes. To further investigate genetic variation among strains in this study, select isolates from each subtype were selected for complete genome sequencing. In addition to providing valuable information about the current diversity of viral strains circulating in the U.S, archiving complete genomes will make it possible to associate viral genotypes with disease phenotypes and track viral evolution over time.

Technical Abstract: Bovine viral diarrhea virus (BVDV) is classified into 2 genotypes, BVDV-1 and BVDV-2, each of which contains distinct subtypes with genetic and antigenic differences. Currently, three major subtypes circulate in the United States: BVDV-1a, 1b, and 2a. In addition, a single case of BVDV-2b infection was reported in the U.S., highlighting the need for continual surveillance to detect emerging viral subtypes. The purpose of this study was two-fold: (i) estimate the current prevalence of BVDV subtypes by sampling persistently infected (PI) beef calves in the central U.S., and (ii) investigate the genetic variation among of these viruses. To determine subtype prevalence, a 283 bp fragment of the 5’ untranslated region was amplified by RT-PCR and sequenced. Phylogenetic analysis of 119 viral strains revealed that a majority (83%) of the strains belonged to genotype 1b, and the remaining strains were distributed similarly between genotype 1a (9%) and 2a (8%). This study did not detect BVDV-2b or other previously unreported subtypes. These prevalences are comparable to those reported 10 years earlier in a similar U.S. sample, suggesting the prevalence of subtypes in PI beef calves in the region has remained relatively constant. To further investigate genetic variation among strains in this study, select isolates from each subtype were selected for complete genome sequencing. In addition to providing valuable information about the current diversity of viral strains circulating in the U.S, archiving complete genomes will make it possible to associate viral genotypes with disease phenotypes and track viral evolution over time.