14-day Susceptibility-guided Bismuth Quadruple Therapy for Multiple Drug Resistant H. Pylori Infection

The investigators design four regimes for H. pylori eradication and participants receive one of the regimens based on susceptibility test. The four regimens are PBAT for those with both amoxicillin and tetracycline susceptible H. pylori; PBAM for those with amoxicillin susceptible but tetracycline resistant H. pylori; PBMT for those with amoxicillin resistant but tetracycline susceptible H. pylori; PBMR for those with both amoxicillin and tetracycline resistant H. pylori. A is amoxicillin (1000 mg thrice daily), B is colloidal bismuth subcitrate (120 mg thrice daily), M is metronidazole (500 mg thrice daily), P is a proton pump inhibitor, i.e., esomeprazole (40 mg twice daily), R is rifabutin (150 mg twice daily), and T is tetracycline (500 mg thrice daily). The treatment duration is 14 days for all regimens.