Recombinase polymerase amplification assay for rapid detection of porcine circovirus 3

The objective of this study was to develop a real-time recombinase polymerase amplification (rt-RPA) assay for the rapid detection of porcine circovirus 3 (PCV3). Specific RPA primers and exo probes were designed for the cap gene of PCV3 within the conserved region of viral genome. The amplification was performed at 38 degrees C for 20 min. The rt-RPA was specific for PCV3, as there was no cross-reaction with other pathogens tested. Using the recombinant plasmid pUC57-PCV3 as template, the analytical sensitivity was 23 copies. Of the 186 clinical samples, PCV3 DNA was identified in the 51 samples by the rtRPA, and the positive rate was 27.4% (51/186). The diagnostic agreement between the rt-RPA and real-time PCR was 96.2%. The R-2 value of rt-RPA and real-time PCR was 0.919 by linear regression analysis. The developed rt-RPA assay shows promise for rapid and sensitive detection of PCV3 in diagnostic laboratories and at point-of-need, thus facilitating the prevention and control of PCV3. (C) 2017 Elsevier Ltd. All rights reserved.