Since the discovery of Helicobacter pylori (H. pylori), many studies have been carried out with the goal of improving H. pylori eradication and therapies have changed from single-antibiotic treatments to the current multi-antibiotic treatments. However, the eradication rate of H. pylori is still less than 80%. The reasons for this low eradication rate are likely to be multi-factorial, including the reduced activity of antimicrobial drugs, poor patient compliance or micro-environment in stomach. In this study, to obtain the higher eradication of H. pylori and discover the different mechanism between the current infection and refractory infection of H. pylori, it is necessary to perform a prevalence survey for eradication of H. pylori based on the results from isolation of H. pylori strains, antibiotic susceptibility testing, CYP2C19 gene polymorphism, drug resistance gene sequencing and 16SrRNA sequencing.

Inclusion Criteria:

1. Age 18~70 years old, male or female, untreated patients.
2. Symptoms of abdominal pain, bloating, acid reflux, belching, nausea, vomiting, heartburn, chest pain, vomiting, melena, etc.
3. Unused antibiotics, bismuth, H2 receptor antagonists or PPI by nearly 4 weeks 4. 13C-labelled urea breath test positive.

5.Agreed to Helicobacter pylori culture and sensitivity testing taken by endoscopy gastric biopsy specimens,and the result of culture was positive.

6.Agreed to Helicobacter pylori eradication therapy and cooperate with the eradication efficacy follow-up survey.

Exclusion Criteria:

1. Severe heart, liver, kidney dysfunction.
2. Pregnant or lactating women.
3. Complications of bleeding, perforation, pyloric obstruction, cancer.
4. Esophageal,gastrointestinal surgery history.
5. Patients can not properly express their complaints,such as psychosis, severe neurosis.
6. Taking NSIAD or alcohol abusers.
7. Allergic to penicillin or either drugs of the 6 antibiotic tested by susceptibility testing.