Prevalence of Caga Gene and Vaca Genotypes of Helicobacter Pylori Among Patients With Gastroduodenal Disseases

Abstract

Background: Helicobacter pylori is an agent of gastric cancer that was classified as a group I carcinogen. cagA and vacA genes of H. pylori play important roles in the pathogenesis of gastroduodenal diseases. This research aimed to: (1) To determine the prevalence of cagA and vacA genotypes of H. pylori among patients with gastroduodenal diseases. (2) To investigate the association between cagA and vacA genotypes and gastroduodenal diseases. Patients and methods: One hundred and fifteen gastroduodenal disease patients infected with H. pylori were enrolled in this study. cagA and vacA genotypes were determined by PCR. Result: The rate of cagA-positive H. pylori strains was 80%. The most common genotype combinations were cagA (+)/ vacA s1m1i1 (39.1%) and cagA (+)/vacA s1m2i1 (25.2%). The cagA (+)/vacA s1m1i1 strain was predominant in peptic ulcer group (59.3%), whereas the cagA (+)/vacA s1m2i1 strain accounted for a high rate in gastric cancer group (75%). Conclusion: Prevalence of H. pylori strains carrying the cagA gene was quite high, and vacA smi genotypes were diverse. cagA (+)/vacA s1m1i1 strain was associated with peptic ulcer disease while cagA (+)/vacA s1m2i1 strain was associated with gastric cancer. Key words: Helicobacter pylori, gene cagA, gene vacA, gastroduodenal diseases.