Growing increase in resistance of H. pylori strains to antibiotics of choice is identified worldwide, requiring further investigating susceptible characteristics of the germ to these agents. Objectives: To assess the resistance of H. pylori individual colonies from a single biopsy to metronidazole and clarithromycin. Methods: The E - test was used to determine the Minimum Inhibitory Concentrations (MICs) of these two antimicrobial drugs for ten H. pylori colonies isolated from an initial gastric biopsy culture from each of 14 adults and 14 children. Results: Among patients haboring HP strains resistant to these 2 antimicrobials, we observed heterogeneity in metronidazole resistance in 14/22 cases and in clarithromycin resistance in 3/13 cases. The number of resistant individual colonies ranged from 2/10 to 9/10 depending on subjects. Conclusions: In the same biopsy from both adults and children different colonies of H. pylori displayed different antimicrobial susceptibility patterns prior to anti - H. pylori treatment, rendering antibiogram interpretation difficult.
Helicobacter pylori, Adult, Child, Metronidazole

PURPOSE: The triple therapy with proton pump inhibitor (PPI) has been recognized as the treatment of choice in Helicobacter pylori (H. pylori) infection in adults. However, the effect of triple therapy with omeprazole, amoxicillin and clarithromycin (OAC) on eradication of H. pylori infection in children has not been established yet. This study was performed to evaluate the efficacy of OAC triple therapy and to compare the effect of one-week with two-week therapy on H. pylori eradication. METHODS: From July 1998 to July 2000, 34 children with upper gastrointestinal symptoms, who underwent upper gastrointestinal endoscopy with biopsy at entry and 4 or more weeks after therapy, were enrolled in this study. H. pylori infection was assessed by CLO test and histologic examination (Hematoxylin-Eosin stain or Alcian yellow stain) with biopsy specimens. The regimen consisted of omeprazole (0.7 mg/kg/day), amoxicillin (50 mg/kg/day), and clarithromycin (25 mg/kg/day) for 1 week (n=21) or 2 weeks (n=13). Eradication of H. pylori was determined after the termination of treatment by the CLO test and histologic examination. RESULTS: One-week treatment group consisted of 21 children (11 male, 10 female) with a mean age of 9.5+/-3.0 years. Two-week group consisted of 13 children (4 male, 9 female) with a mean age of 9.9+/-4.0 years. The endoscopic diagnoses included nodular gastritis in 19 cases, superficial gastritis in 7 cases, gastric ulcer in 4 cases, purpuric duodenitis in 2 cases, and normal in 2 cases. H. pylori was eradicated in 28 of total 34 children (82.4%). In 1-week group, H. pylori was eradicated in 17 of 21 children (81%). In 2-week group, H. pylori was eradicated in 11 of 13 children (84.6%). In remaining 6 cases in whom H. pylori had not been eradicated with OAC regimen, H. pylori infection persisted despite of the treatment with additional drugs such as colloidal bismuth subcitrate (Denol(r)) and metronidazole. CONCLUSION: In this study, eradication rate of H. pylori with OAC regimen was 82.4%, and the triple therapy would be highly effective as primary treatment. However, there was no significant difference in the eradication rate between the 1-week and 2-week treatment group (P=0.785).
Adult ; Amoxicillin* ; Biopsy ; Bismuth ; Child* ; Clarithromycin* ; Colloids ; Diagnosis ; Duodenitis ; Endoscopy, Gastrointestinal ; Gastritis ; Helicobacter pylori* ; Helicobacter* ; Humans ; Male ; Metronidazole ; Omeprazole* ; Proton Pumps ; Stomach Ulcer