Molecular detection of Helicobacter pylori antibiotic resistance in stool vs biopsy samples

AIM To compare(1) demographics in urea breath test(UBT) vs endoscopy patients; and(2) the molecular detection of antibiotic resistance in stool vs biopsy samples.METHODS Six hundred and sixteen adult patients undergoing endoscopy or a UBT were prospectively recruited to the study. The Geno Type Helico DR assay was used to detect Helicobacter pylori(H. pylori) and antibiotic resistance using biopsy and/or stool samples from CLOpositive endoscopy patients and stool samples from UBT-positive patients. RESULTS Infection rates were significantly higher in patients referred for a UBT than endoscopy(overall rates: 33% vs 19%; treatment-na?ve patients: 33% vs 14.7%, respectively). H. pylori-infected UBT patients were younger than H. pylori-infected endoscopy patients(41.4 vs 48.4 years, respectively, P < 0.005), with a higher percentage of H. pylori-infected males in the endoscopy-compared to the UBT-cohort(52.6% vs 33.3%, P = 0.03). The Geno Type Helico DR assay was more accurate at detecting H. pylori infection using biopsy samples than stool samples [98.2%(n = 54/55) vs 80.3%(n =53/66), P < 0.005]. Subset analysis using stool and biopsy samples from CLO-positive endoscopy patients revealed a higher detection rate ofresistance-associated mutations using stool samples compared to biopsies. The concordance rates between stool and biopsy samples for the detection of H. pylori DNA, clarithromycin and fluoroquinolone resistance were just 85%, 53% and 35%, respectively. CONCLUSION Differences between endoscopy and UBT patients provide a rationale for non-invasive detection of H. pylori antibiotic resistance. However, the Geno Type Helico DR assay is an unsuitable approach.