Rapid detection of cagA-positive Helicobacter pylori based on duplex recombinase aided amplification combined with lateral flow dipstick assay

Abstract

Infection with cytotoxin-associated gene A (cagA)-positive Helicobacter pylori (H. pylori) is associated with severe gastrointestinal disease. A rapid, simple, and convenient detection method for cagA-positive H. pylori was an urgent need. We have developed and evaluated a duplex recombinase aided amplification combined with lateral flow dipstick (Duplex RAA-LFD) assay for detection of cagA-positive H. pylori strains. The Duplex RAA-LFD successfully detected DNA extracts in 25 min at 39°C, with visual detection limits of 1.2 × 102 CFU/mL and 10 pg, respectively. No positive amplification was observed in 6 non-H. pylori strains, indicating higher specificity. When testing 56 clinical isolates, the sensitivity and specificity of the Duplex RAA-LFD assay were 96% and 100%, respectively, with Duplex PCR serving as the reference method. Therefore, the Duplex RAA-LFD assay is a potential rapid and effective alternative to detect cagA-positive H. pylori strains in fresh gastric mucosal tissue.