Development and prelim application of TaqMan real-time RT-PCR assays for detection of the variant porcine reproductive and respiratory syndrome virus

A pair of primers and a TaqMan fluorogenic probe were designed by comparing with the Nsp2 gene sequences of the variability porcine reproductive and respiratory syndrome virus(PRRSV) and the normal PRRSV.A real-time RT-PCR assay for the detection of the variability PRRSV was developed by conditional optimize and construction of standard plasmid.The results showed that the real-time RT-PCR assay was specific,and no cross reaction to normal PRRSV and other common porcine viruses.The sensitivity was 0.562 5 TCID50 of the viruses and 264 copy/mL standard plasmid,which was 10 times higher than conventional RT-PCR assay.22 sceptical specimens detected by the real-time RT-PCR showed 36.4%(8 out of 22) positive.The method would be useful for the diagnosis and control of the highly virulent PRRSV.