Expression of the CagA gene ofH. pylori and application of its product

Helicobacter pylori (Hp) plays an important role in the upper digestive tract diseases. It can be divided into two main groups (toxic and non-toxic Hp) according to the production of vacuolating cytotoxin (VacA). The toxic bacteria also produce cytotoxin associated protein A (CagA) which might have something to do with the transcription, folding, transportation or the function of VacA. Studies showed that CagA positive Hp (CagA+Hp) accounted for more than 50% of all kinds of Hp, and peptic ulcer and gastric cancer were closely related to their infection[1-7]. Therefore, detection of the infection of CagA+Hp is of great significance. This study was carried out to express CagA gene in E.coli and develop an immuno-assay for the rapid detection of CagA+Hp.