Metronidazole-resistant Helicobacter pylori strains among Saudi patients with dyspepsia

Objectives: To determine how common are metronidazole-resistant (MTZ-R) Helicobacter pylori (H.pylori) strains in Saudi patients. Design: A prospective study in patients with dyspepsia attending for gastroscopy at Asir Central Hospital, Abha, Saudi Arabia. Methods: Each biopsy specimen was inoculated on a Skirrow's selective medium and incubated at 37 °C under a microaerophilic atmosphere for 3 to 7 days. Suspected colonies were tested further for identification and susceptibility testing. Results: A total of 40 different H.pylori strains were studied. Of the 40 strains isolated, 16 (40.0%) were MTZ-R. Females showed a higher, though not significant, rate of MTZ-R (47%) than males (33%) p=0.37). Furthermore, patients with MTZ-R strains showed lower median age (35 years), compared to those with susceptible ones (45 years). However, the difference was not significant (t=1.89, p=0.07). Moreover, MTZ-R was not significantly affected by the type of endoscopic diagnosis (duodenal ulcer (30%) and gastritis (50%), p=0.20). Conclusions: Since MTZ-R H.pylori strains are frequent (40%), it is recommended to test MTZ susceptibility if possible before treatment, to guide the selection of appropriate therapy and to avoid eradication failure, in particular patients with a history of H.pylori treatment failure. Metronidazole resistance was not affected by age, sex or diagnosis.