Establishment of an indirect ELISA-based method involving the use of a multiepitope recombinant S protein to detect antibodies against canine coronavirus.

Here, we report the development of an indirect enzyme-linked immunosorbent assay (ELISA) method that involves using multiepitope recombinant S protein (rSP) as the coating antigen to detect antibodies against canine coronavirus (CCoV). rSP was designed by arranging its four S fragments (91-135 aa, S1 gene; 377-434 aa, S2 gene; 647-671 aa, S3 gene; 951-971 aa, S4 gene; 207-227 aa) and two T-cell epitopes in tandem: T-E1-E2-E3-E4-T. This multiepitope antigen, which has a molecular weight of approximately 25 kDa and contains a His-tag, was recognized by a CCoV-positive serum in a Western blot assay.