Dual-Priming Oligonucleotide-Based Multiplex PCR for the Detection of Helicobacter pylori and Determination of Clarithromycin Resistance with Gastric Biopsy Specimens

Assessment of Helicobacter pylori (H. pylori) clarithromycin resistance has rarely been performed routinely despite an increasing resistance rate. Our aim was to develop and evaluate the use of dual-priming oligonucleotide (DPO)-based multiplex polymerase chain reaction (PCR) to detect point mutations in the 23S rRNA gene responsible for clarithromycin resistance of H. pylori. Gastric biopsy specimens from 212 untreated patients with dyspepsia were examined by culture, histology, and DPO-based multiplex PCR. A disk diffusion test and E-test were used for performing phenotypic antibiotic susceptibility tests. Among the biopsy specimens tested, 22.2% (47/212), 42.5% (90/212), and 41.5% (88/212) of the specimens were classified as H. pylori positive by culture, histology, and DPO-based multiplex PCR, respectively. Among 96 strains identified by either culture or DPO-based multiplex PCR, 80 strains were clarithromycin-susceptible and 16 strains (16.7%) were clarithromycin-resistant. There was 94.1% (32/34) concordance between phenotypic susceptibility tests and DPO-based multiplex PCR. In two patients with discrepant results, only DPO-based multiplex PCR detected clarithromycin-resistant strains. DPO-based multiplex PCR identified additional 49 clarithromycin-resistant or clarithromycin-susceptible H. pylori among 165 culture-negative specimens. DPO-based multiplex PCR can be used as a practical method for the detection of H. pylori infection and the determination of clarithromycin susceptibility in addition to phenotypic antimicrobial susceptibility tests.