PREVALENCE OF CAGA GENE AND RELATION WITH DIFFERENT CLINICAL FORMS OF HELICOBACTER PYLORI INFECTIONS IN ISOLATED STRAINS OF AHVAZ-SOUTHWEST OF IRAN

Background and Aim:Helicobacter pylori is a gram negative and curved bacterium that infects more than 50% of the Humans. This organism is involved in gastric diseases, including chronic inflammation and ulcers, as well as malignancies.One of the most important virulence factor of helicobacter pylori is the cagA gene.The prevalence of this gene in Iran is about 70%, while in the Western countries it is 60-70% and in the eastern countries is more than 95%.Various studies have shown that the presence of cagA gene in Helicobacter pylori strains increases the risk of gastric ulcer, gastric cancer and MALT lymphoma.Methods:A gastric biopsy specimen was taken from 244 gastric patients and cultivated on a Colombia agar plate containing various antibiotics and incubated for 3 to 5 days under Microaerophilic conditions at 37 ° C.The biochemical tests, were applied to identify the grown strains as H. pylori. Following DNA extraction, polymerase chain reaction were done to find ureC and cagA genes.Results:93 strains of H. pylori were identified . 69 strains had cagA gene( 74% prevalence ).The correlation between the clinical forms of the disease and the cagA gene was analyzed by statistical tests. No significant correlation was found between the clinical forms of the disease and the cagA gene.Conclusion:The reported prevalence of cagA gene in the present study is similar to the some studies conducted in different parts of the world And is difference in other cases. This discrepancy is due to the difference in the type of gastric disorders and the sample size.

Keywords:

cagA-PCR-Helicobacter pylori