Development of a mu3ABC-Based Lateral Flow Immunochromatographic Strip for Rapid DIVA-Compatible Detection of Antibodies Specific to Foot-and-Mouth Disease Virus

Foot-and-mouth disease (FMD) is one of the most infectious viral diseases of cloven-hoofed animals. The crucial strategy for FMD control is the combination of animal quarantine and a rapid onsite diagnostic assay capable of differentiation of infected from vaccinated animals (DIVA). Herein, we have developed a lateral flow immunoassay to detect specific antibodies against FMDV non-structural protein (NSP), based on recombinant mu3ABC produced by E. coli as an antibody detector, the so-called mu3ABC strip test. The performance of this test was examined using 366 field serum samples from cattle, pigs, and goats and compared with the commercial ELISA kit, resulting in a diagnostic sensitivity (DSn) and specificity (DSp) of 98.05% and 93.16%, respectively. Additionally, efficacies of this test and commercial ELISA were determined using 200 reference bovine serum samples (100 positives, 100 negatives) classified by the Regional Reference Laboratory for Foot-and-Mouth Disease in South East Asia (RRL). The result reveals that the DSn and DSp of the test were 78% and 91%, respectively, while those for the commercial ELISA kit were 69% and 100%, respectively. The developed mu3ABC strip tests are effective and can be used to differentiate the infected animals in parallel with the sero-surveillance ELISA test.