Helicobacter pylori virulence factors and their role in peptic ulcer diseases in Turkey

Background and study aims: The role of virulence factors present in Helicobacter pylori (H. pylori) strains and the character- ization of such factors being predictive of specific disease is still not clear. In this study, the cagA, vacA alleles and the recently charac- terized vacA i-region and dupA and their association with the severity of the disease was determined. Patients and methods : Antral biopsies from 91 patients with peptic ulcer (PU) (n = 41), gastritis (n = 48) and gastric cancer (GC) (n = 2) were analyzed for the presence of H. pylori by the CLO-test® and PCR. A 79/91 (86%) patients were positive for H. pylori by either PCR or by both PCR and CLO-test®. PCR- based typing of H. pylori isolates was performed on DNA extracted directly from biopsy samples. Results : The cagA+ strains were found more likely to be associ- ated with vacA s1 than s2. The vacA i1 allele detected in 16/23 (70%) of samples had significant association with duodenal ulcers than those 16/37 (44%) of gastritis (P < 0.04). No significant associ- ation was found between dupA and duodenal ulcer. This study pro- vided more evidence that the vacA i1 allele is one of the virulence factors of H. pylori that had significant association with severe out- come. (Acta gastroenterol. belg., 2010, 73, 235-238).