Establishment of a duplex RT-PCR for the detection of swine influenza virus and porcine reproductive and respiratory syndrome virus.

A duplex RT-PCR assay for swine influenza virus (SIV) and porcine reproductive and respiratory syndrome virus (PRRSV) were developed by using two pairs of primers derived from the M gene of SIV and N gene of PRRSV America strain. The assay was shown to specifically amplify a 325 bp fragment from SIV and 520 bp from PRRSV,whereas no PCR products could be amplified from Classical swine fever virus,pseudorabies virus,porcine parvovirus,porcine circovirus 2 and normal chick embryo allantoic fluid. It was sensitive and could be detect 103 TCID50/0.1 mL PRRSV and 102 EID50/0.1 mL SIV in a mixed sample. Therefore the duplex RT-PCR assay developed here could be an effective method for rapid detection of clinical SIV and PRRSV.