[Prevalence of primary Helicobacter pylori resistance to eight antimicrobial agents in a hospital in Madrid].

The aim of this study was to determine the prevalence of primary Helicobacter pylori resistance, and to investigate the relationship with factors such as age and sex. During 1998, 106 H. pylori strains collected from dyspeptic patients who had had no previous H. pylori treatment were studied. The minimun inhibitory concentrations of metronidazole, amoxicillin, clarithromycin, tetracycline, azithromycin, clindamycin, cefotaxime and ciprofloxacin were determined by E-test.((R)). The overall prevalence of primary metronidazole resistance was 40.6%. Although it was more frequent in women than in men (44.4% vs. 37.7%), the difference was significant only in the women who were under 45 years of age. For the rest of the antibiotics, the primary resistance rates were the following: clarithromycin 9.5%, azithromycin 10.3%, clindamycin 13.1%, and ciprofloxacin 7.9%. No resistance to tetracycline and b-lactam antibiotics was found. Clarithromycin and amoxicillin were the most active compounds of the macrolides and b-lactams studied, respectively.