Development of Indirect ELISA for Antibodies to Foot- and-Mouth Disease Virus and Swine Vesicular Disease Virus
TH Chen1,2*, CH Pan1, F Lee1, YL Lin1, ML Wang1 CN Shih1, HJ Tsai1,2

1Animal Health Research Institute, Council of Agriculture, Executive Yuan
2 Graduate Institute of Veterinary Medicine, School of Veterinary Medicine, National Taiwan University

Abstract

Foot-and-mouth disease (FMD) and swine vesicular disease (SVD) are serious vesicular diseases that have devastated swine populations throughout the world. Indirect enzyme-linked immunosorbent assay (ELISA) based assays can be used to detect antibodies to structural proteins (VP1) of FMD virus O serotype. The structural protein was expressed and purified from a prokaryotic expression system. The recombinant protein was analyzed using Western blot analysis and showed an antigenicity similar to that of FMDV structure protein. Our results have revealed that the diagnostic sensitivity (DSn) and diagnostic specificity (DSp) of ourELISAusing this recombinant protein were 84.1-96.7 % and 93-100 %, respectively. In addition, an indirectELISAbased on recombinant full-length VP1 of SVDV was also developed for the detection of antibodies against SVDV in pigs. The indirectELISAcould detect SVD-specific antibodies from infected pigs as early as six days post-infection with DSn and DSp of 100%. The results obtained from the indirectELISAwere 90-93% and 85-88% consistent with those from commercialELISAkits in detecting imported SVD-negative pigs and local commercial pigs, respectively. The absence of cross-reaction to the antibodies against FMDV, SVDV, and vesicular stomatitis virus (VSV further highlighted the assay’s specificity.

Keywords: foot-and-mouth disease (FMD), swine vesicular disease (SVD),
structural protein (SP), antibody detection, reverse transcription polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), virus neutralization test (VNT).