DPO multiplex PCR as an alternative to culture and susceptibility testing to detect Helicobacter pylori and its resistance to clarithromycin

BACKGROUND: Macrolide resistance in Helicobacter pylori is the major risk factor for treatment failure when using a proton pump inhibitor-clarithromycin containing therapy. Macrolide resistance is due to a few mutations on the 23S ribomosal subunit encoded by the 23S rRNA gene. The present study aimed at investigating the performance of the dual priming oligonucleotide (DPO)-PCR kit named Seeplex(® )ClaR-H. pylori ACE detection designed to detect H. pylori and two types of point mutations causing clarithromycin resistance in H. pylori. METHODS: The performance of Seeplex(® )ClaR-H. pylori ACE detection was evaluated on 127 gastric biopsies in comparison to conventional bacterial culture followed by the determination of susceptibility to clarithromycin by E-test, as well as by an in-house real-time PCR using a fluorescence resonance energy transfer (FRET) technology. RESULTS: Considering culture as the reference test, the sensitivity of DPO-PCR and real-time FRET-PCR was 97.7% and 100% while specificity was 83.1% and 80.7%, respectively. However, both PCR were concordant in detecting 14 H. pylori positive cases which were negative by culture. Globally, E-test and DPO-PCR were concordant with regard to clarithromycin susceptibility in 95.3% of the cases (41/43), while real-time FRET-PCR and DPO-PCR were concordant in 95% (57/60). CONCLUSION: The DPO-PCR is an interesting tool to detect H. pylori on gastric biopsies and to study its susceptibility to clarithromycin in laboratories that cannot perform real-time PCR assays.