DETERMINATION OF BRUCELLA-SPECIFIC ANTIBODIES IN BLOOD SERUM OF YOUNG CATTLE VACCINATED AGAINST BRUCELLOSIS

Abstract

The use of recombinant proteins as a Brucella antigen significantly increased the sensitivity, specificity, and accuracy of in indirect ELISA (iELISA) compared to
RBPT. Immunization of young animals with a full dose of the B. abortus 19 strain vaccine caused in the most animals (69%-94%) a prolonged persistence of  postvaccination anti-protein antibodies detected by i-ELISA for at least 6 months from the day of immunization (observation time).It should be emphasized that in the serum of seropositive animals, antibodies to all used proteins were not always determined simultaneouslybyi-ELISA. In addition, there was no single protein, which in its antigenicity would in no case be inferior to others. These observations provided the basis for testing the combination of Omp19 + Omp25 as a single antigen in studies of the heifer’s blood serums with mutually exclusive antibodies (anti-Omp19 or antiOmp25).As expected, the combined antigen from the two most representative OMPs Brucella increased the sensitivity of the analysis and showing reactivity to antibodies
of both proteins. Thus, the use of individual recombinant Brucella proteins reduces the sensitivity of i-ELISA due to their “omission” of antibodies specific for other proteins. Therefore, the antigen for immunoassay must consist of a combination of two or more recombinant proteins.