Detection of four clarithromycin resistance point mutations in Helicobacter pylori: comparison of real-time PCR and PCR-RFLP methods

Abstract

Helicobacter pylori infection can be eradicated in up to 90 % of patients using current combination of triple therapies, of which clarithromycin is a key component. The development of clarithromycin resistance in H. pylori is recognized as a significant contributing factor in treatment failure. The aim of this study is to compare two fast and direct diagnostic methods to evaluate clarithromycin resistance in gastric biopsy specimens. This cross-sectional descriptive study was performed on 150 gastric biopsy specimens. Analysis for clarithromycin resistance was performed by real-time polymerase chain reaction (PCR) assay for A2144G, A2143G, A2143C, and A2142G point mutations by specific probes. Also, A2142G and A2143G point mutations were detected by PCR-RFLP method and using BsaI and MboII restriction enzymes. Out of 150 samples, 96 (64 %) clarithromycin-sensitive- and 54 (36 %) clarithromycin-resistant strains were detected by TaqMan real-time PCR assay. Thirty-seven (24.67 %) resistant strains were detected by PCR-RFLP method. Results showed that real-time PCR assay has enough accuracy to identify clarithromycin resistance and their mutations in a short time.