Evaluation of the combined use of the recombinant Brucella abortus Omp10, Omp19 and Omp28 proteins for the clinical diagnosis of bovine brucellosis

• Cloning, expression and purification of a recombinant Brucella abortus Omp10, 19 and 28.
• rOmps immunogenicity were confirmed by Western blot with Brucella-positive serum.
• Combined rOmp reacted higher to TAT-positive serum, compared to individual ELISA.
• Combined rOmps: sensitivity (92.67%), specificity (98.66%), and accuracy (96.04%).

Currently, there are several serodiagnostic tools available for brucellosis, however, it is difficult to differentiate an active infection from vaccination. Hence, there is a great need to develop alternative means that can distinguish between these two conditions without utilizing lipopolysaccharide (LPS). This study was an attempt to determine the efficacy of combined recombinant Brucella (B.) abortus outer membrane proteins (rOmps) and individual rOmps in the serodiagnosis of brucellosis by enzyme linked immunosorbent assay (ELISA), utilizing both that standard tube agglutination test (TAT)-positive and -negative serum samples from Korean native cattle. The results are very interesting and promising because the combined rOmp antigens used in the study were highly reactive with the TAT-positive serum samples. The combined rOmps sensitivity, specificity and accuracy were 215/232 (92.67%), 294/298 (98.66%) and 509/530 (96.04%), respectively. While these results are preliminary, the tests performed have very high potential in the serodiagnosis of brucellosis and likewise, the combined rOmps can be used for future vaccine production.