CONSERVED RECOMBINANT ANTIGENS OF ANAPLASMA-MARGINALE AND BABESIA-EQUI FOR SEROLOGIC DIAGNOSIS

The competitive inhibition ELISA (CI-ELISA) format overcomes problems associated with antigen purity since the specificity of the CI-ELISA d epends solely on the monoclonal antibody (mAb) used. Therefore, the CI -ELISA format is well suited for use with recombinant antigens. Molecu lar clones expressing a conserved 19 kDa protein of Anaplasma marginal e and a 34 kDa protein of Babesia equi were derived and characterized. The 19 kDa A. marginale protein, conserved in all recognized Anaplasm a species, and present in the infected tick salivary gland, was reacti ve with all bovine immune sera tested. The 34 kDa B. equi protein cont ains a protein epitope bound by antibody in equine immune sera from 19 countries. Monoclonal antibodies reactive with these proteins were de rived and applied with recombinant copies of the 19 kDa A. marginale a nd 34 kDa B. equi proteins in a CI-ELISA format.