Detection of Helicobacter Pylori Diagnostic Antigens in the Stool of Infected Patients

Background: some antigens of ii. pylori are excreted into thestool of infected people. these antigens can be used to detectthe infection by immunoassays such as elisa. our aim wasto identify these antigens by immunoblotting and affinitychromatography techniques.methods: four different antigenic preparations, namely,whole cell sonicate (wcs), outer membrane proteins (olvll's) ,cytoplasmic antigens (cas) and cell surface-associated antigens(csaas) were obtained from h. pylori. rabbit antiserumagainst these preparations was used to detect them in fecalantigenic extracts (faes) of infected patients.results: by immunoblotting, we were able to detect a 26 kdaband in the positive stool samples. anti-olvll's acted morespecifically, so, it was used to isolate the helicobacter pyloridiagnostic antigens (hpdas) from the stool. more antigens (atleast 4 antigens with the molecular weights of about 14,26,55and 57 kda) were isolated by affinity chromatography. but,the 26 kda antigen had a higher concentration and was seen inalmost all positive samples.conclusion: since the 26 kda antigen is detectable by thesetwo techniques in all positive samples, we are confident thatthis antigen is one of the major antigens of h. pylori, which isreleased into the stool and can be considered as a candidatediagnostic antigen to be used in diagnostic kit development.