BACKGROUND: The aim of this prospective study was to evaluate the usefulness of PCR-based restriction fragment length polymorphism (RFLP) analysis for differentiating H. pylori strains after the triple therapy in patients with duodenal ulcer. METHODS: Following a 1-2 week regimen of omeprazole 40 mg, amoxicillin 2.0 g, and clarithromycin 1.0 g, twice daily, twenty patients with duodenal ulcer were enrolled. Ten patients (group 1) were not successfully treated, and another 10 patients (group 2) exhibited recurrence of infection. Follow-up diagnosis was performed by Giemsa stain and CLO test. RFLP profiles of antral and midbody biopsy specimens were compared before and after therapy. PCR products using the ureC gene were digested with restriction enzymes Hha I, Mbo I, and Hind III, and the fragments generated were analyzed by agarose gel electrophoresis. RESULTS: Hha I, Mbo I, and Hind III digestion produced 13, 7, and 2 distinguishable digestion patterns, respectively. There was no difference in RFLP profiles before and after the therapy in 17 duodenal ulcer patients, while different RFLP profiles following therapy were discovered in 3 patients. Following treatment, one (group 2) patient differed in Mbo I, and two (one each from both groups) patients differed in Hha I and Mbo I RFLP patterns. CONCLUSION: This study supports the hypothesis that PCR-based RFLP analysis can be useful for differentiating reinfection and recrudescence of H. pylori strains following triple therapy.
Amoxicillin ; Azure Stains ; Biopsy ; Clarithromycin ; Diagnosis ; Digestion ; Drug Therapy ; Duodenal Ulcer ; Electrophoresis, Agar Gel ; Follow-Up Studies ; Helicobacter pylori* ; Helicobacter* ; Humans ; Omeprazole ; Polymerase Chain Reaction ; Polymorphism, Restriction Fragment Length* ; Prospective Studies ; Recurrence