Prevalence of Helicobacter pylori resistance to several antimicrobial agents in a region of Germany.

To evaluate the prevalence of resistance among Helicobacter pylori in Germany, the minimum inhibitory concentrations of amoxicillin, tetracycline, clarithromycin, and metronidazole were determined by means of the E test, for 271 Helicobacter pylori isolates cultured from biopsies taken during routine endoscopies in 1996 and 1997. The prevalence of metronidazole resistance was 32.1%, with resistance found more frequently in women (38.5%) than in men (24.4%). Clarithromycin resistance was rare (3.3%). Eight of nine strains resistant to clarithromycin were also resistant to metronidazole. Resistance to either metronidazole or clarithromycin was significantly (P=0.022) higher in patients with duodenal ulcer. No strain was found to be resistant to amoxicillin or tetracycline.