Development of a diagnostic indirect ELISA test for detection of Brucella antibody using recombinant outer membrane protein ۱۶ kDa (rOMP۱۶)

Brucellosis is considered as one of the important global zoonotic diseases that causes medical as well as economic problems especially in tropical countries. The illness has no specific pathognomonic signs; therefore, the rapid and accurate diagnosis of the disease has a very important role in preventing the Brucella spillover and treatment. The purpose of this study was to design a new indirect ELISA test for detection of human brucellosis based on using recombinant Brucella abortus outer membrane protein ۱۶.۰۰ kDa (rOMP۱۶) as an antigen. OMP۱۶ gene of B. abortus was initially synthesized and cloned in pET-۲۱d vector and then expressed in Escherichia coli cells. The expression was confirmed by the SDS-PAGE, western blotting and dot blotting. The purified protein was coated in ELISA plates and an indirect ELISA was performed on ۷۰ human serum samples. The results were evaluated with a commercial IgG ELISA kit and Rose Bengal plate agglutination tests as reference tests. Diagnostic performance of designed OMP۱۶ ELISA test in comparison with Rose Bengal plate test revealed ۱۰۰% of sensitivity, ۹۵.۰۰% of specificity and good Fleiss kappa agreement, whereas, where it was compared to commercial ELISA kit, it revealed very good kappa agreement with ۱۰۰% of sensitivity and ۱۰۰% of specificity in cut-off value of ۰.۱۳. It was concluded that OMP ۱۶.۰۰ kDa could be acceptable alternative antigen for detecting Brucella IgG antibody with high accuracy.

Keywords:

Brucellosis , Indirect ELISA , OMP۱۶ , Sensitivity , Specificity