RESUMEN
Helicobacter pylori [H.pylori] bacteria colonize human stomach mucosa and may establish acute or chronic gastric inflammation. Cytotoxic-associated gene A [cag A] is associated with higher grades of gastric inflammation and carcinoma. in the present study we determine cag A seropositive strain in dyspeptic patients with H. pylori infection. Six hundred adult dyspeptic patients examined for anti H. Pylori and anti-cag A antibodies by enzyme-linked immunoassay [ELISA] method. All cases resided in east Azarbijan in northwest of Iran and were enrolled in a 5-year period [2003-2008]. A total of 85.5% of dyspeptic patients were positive for H. pylori infection. Anti-cag A antibody was detected in 35.6% of patients with H. pylori infection. Screening of H.pylori infection by ELISA method revealed that the vast majority of [85.5%] dyspeptic patients are seropositive for H. pylori. Determining of photogenic strains of H. pylori by anti-cag A antibody could be diagnostic in severe gastric infections