We aimed to compare the efficacy of genotypic resistance-guided tailored therapy vs empirical therapy for eradication of Helicobacter pylori (H. pylori) infection in randomized controlled trials.

Empirical therapy is conventional triple therapy (proton pump inhibitor (PPI) standard dose, amoxicillin 1 g and clarithromycin 500 mg twice a day for 10 days). Genotypic resistance-guided tailored therapy is the method which is chosen by DPO-PCR test. While the patients who have positive result of clarithromycin resistance receive the quadruple therapy(PPI standard dose, bismuth 300mg twice daily, tetracycline 500 mg four times daily, metronidazole 500mg three times daily for 10 days), clarithromycin susceptible patients receive the triple therapy.

H. pylori is difficult to cultivate, cultivation of H. pylori and minimum inhibitory concentration test as a resistance test method are very difficult and take a long time. Recently, tailored treatment based on clarithromycin susceptibility has been proposed by dual-priming oligonucleotide-based multiplex (DPO)-PCR test. This is a method to confirm the mutation of A2142G and A2143G by PCR, which are known to be highly related to the resistance of clarithromycin 23S rRNA point mutation. This test is performed only by gastric biopsy. The examination time is also short as several hours, and sensitivity and specificity are about 80-85%.

Antibiotic resistance of H. pylori, especially clarithromycin resistance, is a cause of major failure of its eradication, and Korea 's clarithromycin resistance rate is reported to be about 37%. The eradication rate of standard triple therapy reported in Korea is also unsatisfactory as antibiotic resistance rate of H. pylori increases. The ideal eradication rate for H. pylori is approximately 90%, but in the meta-analysis of the recently reported primary eradication, the overall eradication rate was 74.6% in the intention to treat analysis.

Inclusion Criteria:

• Patients with H. pylori who had undergone endoscopic resection for gastric neoplasm
• Patients with H. pylori who had diagnosed at peptic ulcer disease, MALT lymphoma

Exclusion Criteria:

• history of gastrectomy
• patients aged younger than 20 years or older than 80 years
• history of H. pylori eradication therapies or other antibiotics therapy within a month
• previous allergic reaction to the study drugs (amoxicillin, clarithromycin, metronidazole, tetracycline, and esomeprazole)
• contraindication to treatment drugs
• pregnant or lactating women
• severe concurrent illness