Antibiotic Susceptibility to Helicobacter pylori Isolated from Patients with Gastric Cancer

ABSTRACT

This investigation was evaluated for in vitro antibacterial activity against 169 Helicobacter pylori strains isolated from patients with gastric cancer in Pusan, Korea. The minimum inhibitory concentration (MIC) of 6 antibiotics was determined by broth microdilution method. The isolation rate of H. pylori was 39.3% in the patients with gastric cancer, and which was not observed any differences between male and female or age group. The MIC50amoxacillin, clarithromycin, and amoxacillin plus clarithromycin against H. pylori isolates was 4.0, 2.0, 0.5, 0.5, 0.5, 1.0, and 1.0 microgram/ml, respectively. The MIC50 of the metronidazole, erythromycin, ciprofloxacin, tetracycline, amoxacillin, clarithromycin, and amoxacillin plus clarithromycin against H. pylori isolates was 32.0, 16.0, 1.0, 1.0, 4.0, 16.0, and 8.0 microgram/ml, respectively. The prevalence of one kind of antibiotic resistant strains of H. pylori was 31.9% for metronidazole, 31.9% for erythromycin, 23.1% for clarithromycin, 11.2% for amoxacillin, 6.5% for ciprofloxacin, and 9.5% for amoxacillin and for clarithromycin. The prevalence of two kinds of antibiotic resistant strains of H. pylori was 8.3% for amoxacillin and clarithromycin, 4.1% for metronidazole and erythromycin, 1.3% for metronidazole and ciprofloxacin, 1.3% for erythromycin and ciprofloxacin. The prevalence of three kinds of antibiotic resistant strains of H. pylori was 5.9% for metronidazole, amoxaciltin, and ciprofloxacin, 2.4% for metronidazole, erythromycin, and ciprofloxacin. The prevalence of four kinds of antibiotic resistant strains of H. pylori was 1.3% for metronidazole, erythromycin, tetracycline, and ciprofloxacin.