Effect of recombinant immunodominant major surface antigen of Echinococcus multilocularis in immunological assay for diagnosis of echinococcosis / 中华检验医学杂志

ABSTRACT

Objective To evaluate effect of the non-fused recombinant antigen in immuno diagnosis of echinococcosis. Methods The coding sequence of the target gene was cloned into prokaryotic non-fusion expression vector pQE30 ( + ) and expressed in E. coli. The recombinant protein was identified by SDS-PAGE and Western Blot, purified with affinity chromatography and used in ELISA to detect specific antibody in patients' sera. Results SDS-PAGE and Western blot demonstrated that Echinococcus multilocularis immunodominant major surface antigen gene was highly expressed in E. coli. The result of ELISA showed that out of 68 echinococcosis sera, 66 samples (97.1% ) were detected positively by the assay. Only 2 samples (2% ) were positive in 100 sera from cases with other infective diseases including cysticercosis or healthy persons. The sensitivity and specificity of the assay were 97.1% and 98% respectively. Conclusion Echinococcus multilocularis immunodominant major surface antigen gene has been highly expressed in E. coli in non-fusion form. ELISA with the recombinant protein is highly sensitive and genus-specific for echinococcosis diagnosis.