Omeprazole therapy for Helicobacter pylori infection.

To determine whether omeprazole eradicates Helicobacter pylori infection of the gastric antrum, six adolescents and one adult with H. pylori colonization of the antrum were entered into a clinical, open trial of medical therapy. Histologic evidence of antral gastritis and three complementary methods to document H. pylori colonization of the stomach (silver stain, urease testing, and culture of antrum) were obtained before and after an 8-week course of omeprazole. In vitro susceptibility to omeprazole and restriction endonuclease analysis were performed on H. pylori isolates obtained from patients before and after omeprazole therapy. Each of the seven patients treated with omeprazole had continued active inflammation in the antrum and one or more features indicative of persisting H. pylori colonization. Minimum inhibitory concentrations and DNA fingerprints of H. pylori isolated after therapy were identical to those of the pre-treatment bacterial isolates in each of the four subjects examined. We conclude that omeprazole therapy alone did not eradicate H. pylori infection of the human antrum. Continued bacterial colonization was not related to either acquired bacterial resistance to the drug or reinfection of the stomach with a different H. pylori strain.