Simultaneous identification of 6 pathogens causing porcine reproductive failure by using multiplex ligation‐dependent probe amplification.

We developed a multiplex ligation‐dependent probe amplification (MLPA) assay for the simultaneous detection of 6 clinically relevant viral pathogens causing porcine reproductive failure, that is porcine reproductive and respiratory syndrome virus (PRRSV), Japanese encephalitis virus (JEV), classical swine fever virus (CSFV), porcine circovirus type 2 (PCV2), pseudorabies virus (PRV) and porcine parvovirus (PPV). The limits of detection for the assay varied among the 6 target organisms from 1 to 8 copies per MLPA assay. The MLPA assay was evaluated with 346 heparinized porcine umbilical cord blood specimens, and the results of the assay were compared to those of real‐time PCR. The MLPA assay showed specificities and sensitivities of 99.2% and 100%, respectively, for PRRSV; 100% and 100%, respectively, for CSFV, PCV2, PRV and PPV. No sample was found to be positive for JEV by either the MLPA assay or the real‐time PCR. In conclusion, the MLPA assay has comparable clinical sensitivity to that of real‐time PCR assay and provides a useful tool for fast screening porcine reproductive failure‐associated viruses. [ABSTRACT FROM AUTHOR]