The chimeric UreB, FliD and Omp18 proteins for a sensitive and specific diagnosis of Helicobacter pylori infections

Helicobacter pylori is known as the main cause of gastrointestinal diseases including gastritis, gastric ulcer and stomach cancer. Serodiagnosis of H. pylori infection is a noninvasive and rapid method but the efficiency of this method is highly dependent to the antigens used. This study evaluated the efficacy of recombinant UreB-Omp18 and FliD for serodiagnosis of H. pylori infection.

The genes encoding for fliD, ureB, and omp18 was amplified by PCR and cloned into pET-22b and pET-28a vectors. The constructs were expressed in E. coli BL21 and purified by affinity chromatography. The antigenic properties and diagnostic potential of the recombinant proteins were analysed by immunoblotting and ELISA, respectively.

The recombinant UreB-Omp18 and FliD with molecular weights of 48 kDa and 25 kDa were observed on SDS- PAGE and purified by the Ni-NTA column. The ELISA results showed that the sensitivity and specificity of recombinant UreB-Omp18 protein in serodiagnosis of H. pylori infection were 89% and 83%, respectively. Also, the sensitivity and spec- ificity of the recombinant FliD protein were calculated to be 91% and 76%, respectively.

The results indicated that the recombinant UreB-Omp18 and FliD could diagnose H. pylori infection with high sensitivity and specificity.