H pylori iceA alleles are disease-specific virulence factors

Abstract

Aim: To characterize and compare genotype profiles of H pylori strains isolated from patients with chronic gastritis and duodenal ulcer in western part of Turkey. Methods: A total of 46 patients [30 chronic gastritis (CG) and 16 duodenal ulcer (DU)] who had undergone endoscopy because of dyspeptic complaints were studied. The antral biopsy specimens were evaluated for the presence of H pylori by rapid urease test and culture, and the genotype profiles were determined by real-time PCR. Results: The cagA gene was observed in 43 (93.5%) isolates. The vacA s1m2 genotype was the predominant subtype, found in 63.3% and 68.7% of isolates in patients with CG and DU, respectively. Twenty (66.6%) isolates from patients with CG were iceA2 positive while the iceA1 was predominant in those with DU (68.8%). In terms of the association of the iceA alleles to other genes, both alleles were significantly associated with the cagA vacA s1m2 genotype. Conclusion: The prevalent circulating genotypes in CG and DU were cagA vacA s1m2 iceA2 and cagA vacA s1m2 iceA1 genotype, respectively. It was found that cagA vacA s1m2 genotype seems to be common virulence factors in both CG and DU while iceA alleles show specificity for gastroduodenal pathologies in this study. © 2007 The WJG Press. All rights reserved.