Distribution of cagG gene in Helicobacter pylori isolates from Chinese patients with different gastroduodenal diseases and its clinical and pathological significance

摘要

AIM: To determine the distribution of cagG gene of Helicobacter pylori (H pylori) isolates cultured from patients with various digestive diseases and its relationship with gastroduodenal diseases. METHODS: cagG was amplified by polymerase chain reaction in 145 H pylori isolates cultured from patients with chronic gastritis (n=72), duodenal ulcer (n=48), gastric ulcer (n=17), or gastric and duodenal ulcer (n=8), and the relationship between cagG status and the grade of gastric mucosal inflammation was determined. RESULTS: cagG was present in 91.7 % of the 145 H pylori isolates, with the rates were 90.3 %, 93.8 %, 88.2 % and 100.0 %, respectively, in those from patients with chronic gastritis, duodenal ulcer, gastric ulcer, and gastric and duodenal ulcer. There was no significant difference among the four groups (P>0.05). The average grade of gastric mucosal inflammation in the antrum and corpus was 1.819+-0.325 and 1.768+-0.312, respectively in cagG positive patients, whereas the average inflammation grade was 1.649+-0.297, 1.598+-0.278 respectively in cagG negative cases (P>0.05). CONCLUSION: cagGgene of H pylori was quite conservative, and most H pylori strains in Chinese patients were cagGpositive. cagGstatus was not related to clinical outcome or the degree of gastric mucosal inflammation. Therefore, cagG can not be used as a single marker for discrimination of H pylori strains with respect to a specific digestive disease.