We developed monoclonal antibody-based sandwich direct ELISA (MSD-ELISA) for antigen detection of foot-and-mouth disease virus (FMDV). In this study, we evaluated and compared the sensitivity and specificity of MSD-ELISA with conventional indirect sandwich (IS)-ELISA by using both experimental samples and field samples. We developed two types of MSD-ELISA, using different detection monoclonal antibodies: (1) for multiple serotypes and (2) for single serotypes for each serotype (O, A, Asia1). The MSD-ELISAs could detect the antigen in saliva samples of experimentally infected pigs of other topotypes of serotypes O, A and Asia1 for a longer term than IS-ELISA. We also used 178 RT-PCR-positive field samples from cattle and pigs affected by the 2010 type-O FMD outbreak in Japan, and found that the sensitivity of both MSD-ELISAs was about 7 times higher than that of the IS-ELISA for each sample. Further, the sensitivity of the MSD-ELISAs was about 6 times higher than that of the IS-ELISA for each farm, with respect to the FMD-positive farm detection rate. Although it is necessary to conduct further validation studies using other virus strains, the MSD-ELISAs could be a better method than IS-ELISA for FMD antigen detection.
(Exotic Diseases Research Division)
Morioka K. et al (2014) PLoS ONE 9(4):e94143