The changing sensitivity of Helicobacter pylori to metronidazole

The objective was to determine over two periods, seven years apart, the sensitivity of H. pylori isolates to metronidazole, tetracycline and erythromycin. The study periods were 1987/88 and 1995/96 and the population consisted of 133 patients undergoing upper gastrointestinal endoscopy for peptic ulcer disease in KFHU. The sensitivity of H. pylori isolates from their biopsy specimens was tested to three antibiotics using the disc diffusion method. In 1987/88, 62%, 97.0% and 98.6% of isolates were sensitive to metronidazole, erythromycin and tetracycline respectively. The corresponding sensitivities in 1995/96 were 14.5, 93.5% and 100% respectively. In 1987/88 there was no difference in the metronidazole resistant H. pylori isolates from men and women (38.2% vs 37.5%) but in 1995/96 slightly more women than men had metronidazole resistant isolates (89% vs 82.9%). The resistance of H. pylori to metronidazole increased over time. In order to improve outcome of treatment, sensitivity of H. pylori isolates needs to be determined for each patient. The recommended triple therapy requires to be modified if the prevailing sensitivity pattern of H pylori in our environment is taken into account.