Antibiotic Susceptibility of Helicobacter pylori Clinical Isolates in Hamadan, West of Iran

Background: Surveillance data on Helicobacter pylori antibiotic susceptibilities are limited in Hamadan, Iran. Since antibiotic resistance is one of the reasons in therapies failure. Objectives: Thus the resistance patterns of H. pylori strains to the antibiotics metronidazole, clarithromycin, amoxicillin and tetracycline were evaluated. Patients and Methods: Gastric biopsy specimens of 153 patients with nonulcer dyspepsia, peptic ulcer dyspepsia, and peptic cancer collected during May 2010 to February of 2011, and were cultured on Brucella agar (Merck, Germany) under microaerophilic conditions. H. pylori isolates were identified using standard biochemical test. Eighty three (54.2 %) specimens had positive results by culture. Antimicrobial susceptibility testing was performed by disc diffusion method. Results: Totally in vitro resistance rates were 63.8% for metronidazole, 26.5% for clarithromycin, and 7.2% for amoxicillin. Although, 25.3% of strains showed resistance to two antibiotics, and 3.6% to three antibiotics. Tetracycline resistance was identified in only two isolates. Fifty nine percent of the clarithromycin resistant strains also showed resistance to metronidazole. No gender and age associations with resistance were detected. Conclusion: Our results showed a high incidence of metronidazole resistance (often combined with clarithromycin-resistance) in the isolates. Continuous surveillance is recommended to examine the treatment strategies for H. pylori eradication.