Detection of the clarithromycin resistance of Helicobacter pylori in gastric mucosa by the amplification refractory mutation system combined with quantitative real-time PCR.

ABSTRACT

The goal of this study was to evaluate the feasibility of detecting Helicobacter pylori clarithromycin resistance in gastric mucosa using the amplification refractory mutation system combined with quantitative real-time PCR (ARMS-PCR). Gastric mucosal specimens (150) were collected from patients who were unsuccessfully treated for H. pylori eradication. Each specimen was divided into 2 samples. One sample was used to extract genomic DNA and detect any gene mutations of H. pylori produced by ARMS- PCR. Sequencing was used to assess the accuracy of this method. The other sample was used to culture H. pylori. The E-test minimum inhibitory concentration (MIC) was used to assess clarithromycin resistance. The results were compared with a paired chi-square test to validate the coincidence rate among the 3 methods. The coincidence rate between the sequencing and ARMS-PCR results was 98.7%, thus verifying the accuracy of ARMS-PCR. E-tests detected 144 clarithromycin resistance cases, including 45 sensitivity cases; the resistance rate was 70%. The coincidence rate between the results of the E-test and ARMS-PCR was 97.1%, and no significant difference between the 2 methods was observed. ARMS-PCR is a simple and fast method that has high sensitivity and specificity and can be used to detect the clarithromycin resistance of H. pylori in gastric mucosa. ARMS-PCR is expected to be used to study drug resistance mechanisms and use in assays of individual therapies for H. pylori eradication.