Establishment of TaqMan probe dual real-time PCR Assay for the Identification of NADC34-like PRRSV based on GP5 gene

Porcine reproductive and respiratory disorder syndrome virus (PRRSV) is an RNA virus that can clinically cause reproductive disorders in sows and respiratory diseases in growing pigs. Recently, NADC34-like PRRSV has been reported to become prevalent gradually and an outbreak in pig farms in China. Additionally, there is no precise detection method for clinical testing. Therefore, in this study, a TaqMan probe dual real-time quantitative fluorescence detection method based on M and GP5 genes was developed to distinguish NADC34-like PRRSV by specific amplification of the GP5 gene. The method is strongly specific, only NADC34-like PRRSV was accurately detected. Besides, the maximum limit of detection of pMD-M and pMD-GP5 sensitivity was 2.67 × 10 2 copies/µL and 1.35 × 10 1 copies/µL, respectively. The method was reproducible and the coefficient of variation (CV) values of both recombinant plasmids were <2%. In the progress detection of 251 clinical samples, it was found that 27 NADC34-like PRRSV may be accurately detected by the method. Overall, this study was the first to establish an accurate and sensitive probe dual real-time PCR for NADC34-like PRRSV based on GP5 gene, which provides effective support and methods for clinical testing in pig farms.