Development of an automatic tubular chemiluminescence immunoassay using magnetic particles for the detection of antibodies against foot-and-mouth disease virus serotype A.

Foot-and-mouth disease virus (FMDV) causes significant financial losses in animal farms worldwide. Specific antibody monitoring of FMDV post-vaccination is important for evaluating vaccine efficacy, as well as the prevention and control of foot-and-mouth disease (FMD). In this study, we developed a fully automatic tubular chemiluminescence immunoassay method based on magnetic particles (A-MPCLIA) to specifically detect antibodies against FMDV serotype A. The diagnostic sensitivity (Dsn) and diagnostic specificity (Dsp) of A-MPCLIA were determined to be 96.05 % and 99 %, respectively, with a cut-off value of 30 activity units (U) by detecting the known background swine, cattle, and sheep serum. The developed method presented good Dsn, Dsp, and repeatability (CV < 10 %). The activity units of A-MPCLIA, determined using 23 animals vaccinated with FMDV serotypes O, A, and Asia 1 univalent inactivated vaccine and nine serum samples from naïve animals, were significantly positively correlated with the titers of liquid-phase-blocking enzyme-linked immunosorbent assay (R2 = 0.992) and the titer of the virus neutralization test (R2 = 0.9577). In addition, A-MPCLIA requires less than 20 min, and it is fully automatic in detection. These results showed that A-MPCLIA is a suitable method for the detection of antibodies against FMDV serotype A in the future.