INVESTIGATION OF Helicobacter pylori VIRULENCE GENOTYPE IN GASTRIC BIOPSIES BY PCR

Background: Helicobacter pylori infections has been associated with the genetic diversity of their virulence factors, the virulence genotypes are valuable as molecular marker in the diagnosis of patients with bacterial infections . Our main objective was to analyze the frequency and allelic genotype of vacA , cagA also investigate another virulence genes of H. pylori. Methods: 75 biopsies of patients with gastritis and peptic ulcer diseases were selected to investigate the presences of H. pylori and collected from them antrum biopsies, then genomic DNA was extracted from antrum biopsies using genomic DNA kit .Subsequently, the virulence genes of H. pylori were amplified using specific primers including vacA , cagA, cagE and oipA and iceA by PCR in 49 cases that positive to 16SrRNA which previously investigated. Results: A high prevalence of genes cagA (28.6%), vacAs1bm2 (56.8%), iceA2 (30.6%) and oipA (42.9%) was found, while vacA s2m1 and iceA1 genotypes was not found in our study. There was significant correlation between the presence of cagA and cagE genotypes (p = 0.02), suggesting that these two genes almost used together as cag PAI integrity marker. The presence of cagA gene was significantly associated with peptic ulceration (p ≤ 0.001), whereas different vacA genotypes or iceA2 genotype were no statistically significant with clinical outcome. Patients with peptic ulcer disease more likely to have oipA gene (61.9% ) than those with gastritis (38.1%), P = 0.037, also the presence oipA gene was statistically significant with presence iceA2. Conclusion : Most H. pylori genotypes which associated with peptic ulcer and gastritis were moderate virulent strains.