Analysis of antibiotic susceptibility patterns of Helicobacter pylori isolates from Malaysia.

BACKGROUND

The prevalence of antibiotic resistance varies in geographic areas. The information on the antibiotic susceptibility patterns of Helicobacter pylori (H. pylori) in our local setting is therefore relevant as a guide for the treatment options.

OBJECTIVE

This study was conducted to determine the primary resistance rates among H. pylori isolated from Malaysian patients.

MATERIALS AND METHODS

Biopsy samples were obtained from the stomach antrum and corpus of 777 patients from September 2004 until 2007. H. pylori isolated from these patients were then subjected to minimum inhibitory concentration (MICs) determination using E-test method, against metronidazole, clarithromycin, levofloxacin, ciprofloxacin, amoxicillin, and tetracycline.

RESULTS

From 777 patients, 119 were positive for H. pylori where a total of 187 strains were isolated. The resistance rates were noted to be 37.4% (metronidazole), 2.1% (clarithromycin), 1% (levofloxacin and ciprofloxacin), and 0% (amoxicillin and tetracycline). Different resistance profiles were observed among isolates from the antrum and corpus of 13 patients. Resistance to one type of antibiotic was observed in 36.4% of the strains where mono-resistance to metronidazole was the most common. Resistance to ≥2 antibiotics was noted in 3.3% of isolates. High metronidazole MICs of ≥256 μg/mL were observed among the resistant strains.

CONCLUSIONS

The resistance rates of the antibiotics used in primary treatment of H. pylori infections in Malaysia are low, and multi-antibiotic-resistant strains are uncommon. Infections with mixed populations of metronidazole-sensitive and -resistant strains were also observed. However, the high metronidazole MIC values seen among the metronidazole-resistant strains are a cause for concern.