|Givens, M. Daniel|
Submitted to: Veterinary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/10/2007
Publication Date: 11/15/2007
Citation: Gripshover, E.M., Givens, M.D., Ridpath, J.F., Brock, K.V., Whitley, E.M., Sartin, E.A. 2007. Variation in E(rns) viral glycoprotein associated with failure of immunohistochemistry and commercial antigen capture ELISA to detect a field strain of bovine viral diarrhea virus. Veterinary Microbiology. 125(1-2):11-21. Interpretive Summary: Bovine viral diarrhea viruses (BVDV) are economically important pathogens of cattle worldwide. BVDV can establish persistent life long infections as a result of fetal infection. Persistently infected (PI) animals are the primary means of introduction of BVDV into susceptible herds. In the U.S. control programs to reduce BVDV losses are based on the detection and removal of PI animals before they can infect new herds. The only currently available commercial test for BVDV detection relies on the binding of a monoclonal antibody to the virus present in the skin and blood of PI animals. In this report we describe a BVDV strain that escapes detection with the commercial kit. The ability of a BVDV strain, to evade detection, compromises the BVDV control program. These findings suggest that tests should be designed that use more than one monoclonal antibody for detection.
Technical Abstract: Bovine viral diarrhea virus (BVDV) effects cattle populations causing clinical signs that range from subclinical immunosuppression to severe reproductive and respiratory problems. Detection and removal of persistently infected (PI) calves is the single most important factor for control and eradication of BVDV. Current testing strategies to detect PI calves rely heavily on immunohistochemistry (IHC) and a commercially available antigen capture ELISA (ACE) assay. These viral assays depend on 1 or 2 monoclonal antibodies (Mab's) that target the E**rns glycoprotein of BVDV. The sensitivity and specificity of these two tests have been reported previously in the literature. The purpose of this research was to characterize a strain of BVDV (AU 501) that was undetectable using IHC and ACE tests based on a Mab that binds the E**rns, but was consistently detected in samples from a Holstein steer by virus isolation and polymerase chain reaction based tests. Sequencing of this AU 501 viral isolate revealed a unique mutation in the portion of the genome coding for the E**rns glycoprotein of the virus. This unique field strain of BVDV demonstrates the risk of relying on a single monoclonal antibody for detection of BVDV. Multiple testing strategies, including polyclonal or pooled monoclonal antibodies that detect more than one viral glycoprotein may be necessary to detect all PI calves and facilitate eradication of BVDV.