Prevalence of Helicobacter pylori vacuolating cytotoxin and its allelic mosaicism as a predictive marker for Iranian dyspeptic patients.

Helicobacter pylori infects the majority of the population in the developing countries. However, the rate of gastrointestinal complications such as peptic ulcers and gastric malignancies has no parallel with the infection. In order to determine whether cytotoxin (vacA) and its allelic polymorphism can serve as screening markers for such a population, H. pylori strains were isolated from one hundred and thirty two dyspeptic patients. H. pylori genomic DNA was extracted and underwent PCR-amplification for the cytotoxin alleles. Genotyping of the signal sequence region of the vacA gene identified 68% (70 out of 103) of patients with non ulcer dyspepsia (NUD) and 79% (23 out of 29) of the patients with peptic ulcer disease (PUD) possessing the s1 genotype. S1 strains were significantly more prevalent among patients with PUD as compared to the NUD (p < 0.05). In regard to the middle region, 55% of the patient isolates belonged to the m2 genotype with no correlation to disease. The s1m2 genotype was the most prevalent among all patients and significantly correlated with the PUD group (p < 0.05).