Development of a peptide-based immunochromatographic strip for differentiation of serotype O Foot-and-mouth disease virus-infected pigs from vaccinated pigs.

An immunochromatographic strip for discriminating Foot-and-mouth disease virus (FMDV) infected from vaccinated pigs was developed based on synthetic peptide. Five peptides designed from the amino acid sequences of nonstructural proteins (NSP) of FMDV were synthesized, and pep5 located in NSP 3B reacted strongly with serum from FMDV-infected pigs but did not react with serum samples from healthy vaccinated pigs. An immunochromatographic strip was developed by using colloidal gold labeled with pep5 as the detector. Staphylococcal protein A and rabbit against peptide-conjugated ovalbumin antibody immunoglobulin G were blotted on the nitrocellulose membrane for the test and control lines. In comparison with 2 commercial NSP enzyme-linked immunosorbent assays, the peptide-based strip showed good specificity and sensitivity. The apparent agreements of this new assay with Ceditest(R) ELISA and UBI(R) ELISA were 98.59% and 96.63%, respectively. These results indicate that the strip can be adequately used to discriminate FMDV-infected animals from vaccinated animals.