Establishment of a CRISPR/Cas12a/13a-driven dual-detection platform for rapid diagnosis of swine influenza virus and porcine reproductive and respiratory syndrome virus infection

Abstract

Background: Swine influenza virus (SIV) and porcine reproductive and respiratory syndrome virus (PRRSV) are leading pathogens in pigs, whose co-infections exacerbate disease severity. Current diagnostics like RT-PCR lack suitability for rapid, on-site use, while CRISPR-based systems face challenges in convenient multiplex detection.

Results: We developed an RT-LAMP-CRISPR-Cas12a/13a-LFD dual-detection platform that integrates reverse transcription loop-mediated isothermal amplification (RT-LAMP) with the orthogonal trans-cleavage activities of CRISPR-Cas12a and Cas13a, followed by lateral flow dipstick (LFD) visualization. This assay achieved detection limits of 5 copies/µL for SIV and 2 copies/µL for PRRSV, and exhibited high specificity against other common swine pathogens. The entire process, including a 20-minute amplification at 40 °C and 5-minute LFD readout, enables rapid and visual diagnosis. A preliminary validation was conducted using respiratory infection samples, demonstrating high concordance with reference methods and specificity against non-target pathogens.

Conclusions: The RT-LAMP-CRISPR-Cas12a/13a-LFD assay provides a sensitive, specific, and potentially field-adaptable tool for the simultaneous detection of SIV and PRRSV. It is ideally suited for early screening and precise control of these pathogens in resource-limited settings.

Keywords: CRISPR-Cas12a/13a; Lateral flow dipstick (LFD); Porcine reproductive and respiratory syndrome virus (PRRSV); Reverse transcription loop-mediated isothermal amplification (RT-LAMP); Swine influenza virus (SIV).