Development and evaluation of an ELISA to measure antibody responses to both the nucleocapsid and spike proteins of canine coronavirus.

A rapid and reproducible enzyme linked immunosorbent assay (ELISA) was developed for detection of canine coronavirus (CCV) specific antibodies directed to both the nucleocapsid (NC) and the spike (S) proteins. The coating antigen, a methanol-treated, S-protein enriched preparation, was produced by subjecting infected cells to Triton X-114 detergent followed by phase separation. The sensitivity of this assay was determined by following the course of infection in dogs experimentally infected with CCV. The specificity of the antibody response was determined by Western blot analysis and supported the increased magnitude of the ELISA response and the presence of serum neutralizing (SN) antibody. Due to the sensitivity and specificity of the IgG response detected by this assay it can be used to determine both virus exposure and vaccine efficacy.