patients who had failed previous H. pylori eradication on standard triple therapy were randomized into two regimens: 1, esomeprazole (20 mg b.i.d), tripotassium dicitrate bismuthate (300 mg q.i.d), metronidazole (500 mg t.i.d), and tetracycline (500 mg q.i.d) (EBMT) or 2, moxifloxacin (400 mg q.d.), esomeprazole (20 mg b.i.d), and amoxicillin (1000 mg b.i.d.) (MEA). At four weeks after completion of eradication therapy, H. pylori tests were performed with 13C urea breath test (UBT) or invasive tests (Giemsa histology, CLO test, and culture). In patients who maintained continuous H. pylori negativity for the first year after eradication therapy, H. pylori status was assessed every year. For the evaluation of risk factors of reinfection, gender, age, clinical diagnosis, histological atrophic gastritis or intestinal metaplasia were analyzed.

Inclusion Criteria:

• Patients were considered persistent H. pylori infection if 13C-urea breath test (UBT) or invasive H. pylori test (Giemsa histology, CLO test, culture) were positive despite PPI-based triple therapy.

Exclusion Criteria:

• Patients were excluded from the study if they had a history of renal or hepatic impairment, previous gastric surgery, pregnancy or lactation, therapy with steroids or non-steroidal anti-inflammatory drugs, or therapy with a proton pump inhibitor (PPI) or antibiotics within four weeks of entry.