Based on multiplex-PCR results which were performed using 18 patients with ulcer and 62 patients with gastritis, no statistically significant difference was detected for the existence of H. pylori cagA, hpaA, oipA, babA, vacAs1, vacAs2, vacAm1, vacAm2, ureA, ureB and dupA virulence factors among patients with gastritis and ulcer (Table 3). This evidence concerns the gene S100A8 and ulcer disease.