Association of H. pylori virulence genes CagA, VacA and UreAB with ulcer and nonulcer diseases in Iranian population.

To evaluate the association of virulence genes CagA, VacA and UreAB of H. pylori with the development of different gastric disorders, polymerase chain reaction was performed on H. pylori organisms isolated from biopsy samples of stomach of patients with ulcerative disease and nonulcerative disease. The difference between the groups was statistically significant (p < 0.05) only for VacA gene. We detected 8 phenotypes, characterized as CagA(+)-VacA(-)-UreAB(+) (phe 1), CagA(-)-VacA(-)-UreAB(-) (phe 2), CagA(+)-VacA(+)-UreAB(-) (phe 3), CagA(+)-VacA(-)-UreAB(+) (phe 4), CagA(-)-VacA(+)-UreAB(+) (phe 5), CagA(+)-VacA(-)-UreAB(-) (phe 6), CagA(-)-VacA(+)-UreAB(-) (phe 7), CagA(-)VacA(-)-UreAB(+) (phe 8). The prevalence of phenotype 1 was significantly higher in the patients with UD than that in the patients with NUD (p < 0.05). These results suggest that in the population under our study, being infected by a H. pylori strain with the genotype CagA(+)-VacA(+)-UreAB(+) may be associated with an increased risk of acquiring an ulcer disease.