Visual detection of porcine reproductive and respiratory syndrome virus using CRISPR-Cas13a.

Porcine reproductive and respiratory syndrome virus (PRRSV) has varied constantly and circulated in the pig industry worldwide. The prevention and control of porcine reproductive and respiratory syndrome (PRRS) is complicated. A visual, sensitive and specific diagnostic method is advantageous to the control of PRRS. The collateral cleavage activity of LwCas13a is activated to degrade non-targeted RNA, when crRNA of LwCas13a bond to target RNA. The enhanced Cas13a detection is the combination of collateral cleavage activity of LwCas13a and recombinase polymerase amplification (RPA). In this study, the enhanced Cas13a detection for PRRSV was established. The novel method was an isothermal detection at 37°C, and the detection can be used for real-time analysis or visual readout. The detection limit of the enhanced Cas13a detection was 172 copies/μl, and there were no cross-reactions with porcine circovirus 2, porcine parvovirus, classical swine fever virus and pseudorabies virus. The enhanced Cas13a detection can work well in clinical samples. In summary, a visual, sensitive and specific nucleic acid detection method based on CRISPR-Cas13a was developed for PRRSV.