Antibiotic resistance in Helicobacter pylori varies according to geographical region. We studied the primary resistance rates among 652 H. pylori isolated from Korea in relation to collection date, disease presentation, age and gender. Resistance rates were 40.6% (metronidazole), 5.9% (clarithromycin), 5.3% (tetracycline), 0% (amoxycillin), 1.5% (furazolidone) and 1.5% (nitrofurantoin). Resistance to metronidazole and clarithromycin increased from 1994 to 1999 (from 33.3 to 47.7% and 4.8 to 7.7%, respectively), but the differences only reached significance when rates of metronidazole resistance in women were compared with those in men (48.6 versus 36.9%).

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Analysis of metronidazole, clarithromycin and tetracycline resistance of Helicobacter pylori isolates from Korea

The influence of in vitro nitroimidazole resistance on the efficacy of nitroimidazole-containing anti-Helicobacter pylori regimens: a meta-analysis.

Recently, the development of antibiotic resistance emerged as a significant clinical problem in the eradication of Helicobacter pylori. We investigated the MICs of antibiotics for 135 H. pylori isolates from adults in Seoul, South Korea, over the past 16 years. The MICs of amoxicillin, clarithromycin, metronidazole, tetracycline, azithromycin, and ciprofloxacin increased from 1987 to 2003. Rates of primary resistance to clarithromycin increased from 2.8% in 1994 to 13.8% in 2003. The A2144G mutation was frequently observed in the 23S rRNA gene in clarithromycin-resistant isolates. The increase in resistance to clarithromycin seems to result in a decrease in eradication efficacy for H. pylori. These results suggest that the MICs of several antibiotics for H. pylori have increased over the past 16 years in Seoul.

Distribution of antibiotic MICs for Helicobacter pylori strains over a 16-year period in patients from Seoul, South Korea

The susceptibilities to three antimicrobials of 195 Helicobacter pylori strains isolated from Mexican patients is reported; 80% of the strains were resistant to metronidazole, 24% were resistant to clarithromycin, and 18% presented a transient resistance to amoxicillin. Resistance to two or more antimicrobials increased significantly from 1995 to 1997.

Increasing multidrug resistance in Helicobacter pylori strains isolated from children and adults in Mexico.

Antibiotic resistance problems with Helicobacter pylori.

The prevalence of primary metronidazole resistance of Helicobacter pylori was studied in one Dutch hospital from 1993 to 1996 and in two additional Dutch hospitals in 1993 and 1996. All cultures of antral biopsy specimens yielding H. pylori in the study period were evaluated, except those from patients who had received anti-H. pylori treatment; 1,037 H. pylori strains, all from different patients were included. Metronidazole resistance was determined by disk diffusion in 1993 and by Epilipsometer-test in 1994 to 1996. Metronidazole resistance increased from 7% (18/245) in 1993 to 32% (161/509) in 1996. More patients with nonulcer dyspepsia and more non-Western European patients were seen in 1996 than in 1993, but age and sex differences were not observed. A comparable increase in metronidazole resistance was observed in both nonulcer dyspepsia patients and peptic ulcer patients, and the prevalence of metronidazole resistance in Western Europeans increased from 5% in 1993 to 28% in 1996.

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EJ vanderWouden

Papers

Rapid increase in the prevalence of metronidazole-resistant Helicobacter pylori in the Netherlands

Reliability of biopsy-based tests for H-pylori after treatment.