Development of VP2 indirect ELISA for detection of cattle antibodies against foot-and-mouth disease virus.

The complete gene encoding the structural protein VP2 of FMDV was subcloned into expression vector pPROEXTM HTb and expressed in DH5α cells. Purified VP2 protein reacted positively with serotype-specific cattle sera of 5 serotypes of FMDV (O, A, C, SAT 2 and AsiaⅠ) by western blot. An indirect ELISA (VP2-ELISA) was developed using purified protein as coating antigen to detect FMDV antibodies in cattle. The assay was highly specific and showed no cross-reaction with the positive sera of other bovine diseases. The sensitivity of the assay was 97.3 % against infected sera. Comparison with four commercial kit showed a coincidence rate of 69.0 %, 95.0 %, 90.4 % and 86.8 % against positive cattle serum, respectively.