Rapid Detected and Diagnostic Assessment Vacuolating Cytotoxin A (vacA) Gene of Helicobacter pylori by Loop-Mediated Isothermal Amplification (LAMP)

Abstract

The loop-mediated isothermal amplification (LAMP) assay as efficient and convenient detection method was applied to detect the vacuolating cytotoxin A (vacA) gene of Helicobacter pylori (H. pylori). The extracted genomic DNA of H. pylori, which was purified through magnetic nanoparticles (MNPs), was amplified through the LAMP reaction using designed primers. The effect of LAMP detected on H. pylori vacA gene was evaluated through agarose gel electrophoresis in a gel imaging system and fluorescence-intensity analysis after addition of fluorescent dye. 11 pathogenic bacterial strains of different species were found to be negative for vacA, while only a single positive result was obtained for H. pylori. The minimum detection limit of the vacA gene was established as 100 fg. We used the primers with specificity and sensitivity, which were designed by the specificity analysis and sensitivity analysis system. Once developed, the LAMP assay was be used to the detection of the vacA gene in the gastric juice of patients. In conclusion, the LAMP assay is an efficient and fast tool for detection of the H. pylori vacA gene, and also for direct detection of the vacA gene in the gastric juice of patients, with high sensitivity and specificity. Most importantly, the proposed detection method shows promising potential for clinical application in the future, where it can greatly reduce the difficulty of detection and also shorten detection times.