Cross-priming amplification-based lateral flow strip as a novel tool for rapid on-site detection of wild-type pseudorabies virus

Pseudorabies (PR), also called as Aujeszky's disease, is an important infectious disease of pigs and other mammals caused by pseudorabies virus (PRV). This paper presents a novel assay based on cross-priming amplification in combination with gold nanoparticle lateral flow strip (CAP-strip) for rapid and on-site detection of wild-type PRV. In the assay, FITC and biotin were labeled at the 5'-ends of the two probes, respectively, resulting in amplified products labeled with either FITC or biotin at the 5'-end. Then the amplified products (biotin-dsDNA-FITC), as novel targets, were recognized by standardized strips. The assay had excellent visualization results from 2.0 x 10(2) to 2.0 x 10(8) copies of PRV and the detection limit was determined to be 200 copies. No cross-reactivity was observed with several common porcine viruses. When testing a total of 293 field swine samples, the agreement between the CPA-strip assay and a triplex real-time PCR or virus isolation were 100% (293/293) or 97.3% (285/293). Collectively, the assay is specific, sensitive and convenient that enables rapid, on-site diagnosis of PRV infections. (C) 2017 Elsevier B.V. All rights reserved.