THE USE OF MONOCLONAL-ANTIBODIES IN THE DIAGNOSIS OF CONTAGIOUS CAPRINE PLEUROPNEUMONIA (CCPP)

Contagious caprine pleuropneumonia is a severe disease affecting goats in Eastern Africa and the Middle East, caused by Mycoplasma sp. type F38. Its exact geographical distribution is however not exactly known due to the lack of specificity of the available serological tests and the difficulty in cultivating M. sp. F38. A panel of monoclonal antibo dies (mAbs) was produced, using crude or membrane proteins antigens fr om type F38 strains to immunize mice. The reactivity of the mAbs was t ested by an immunobinding assay with crude mycoplasma antigens spotted on nitrocellulose filters. One hundred and twelve antigens, standardi zed at 0.5 mg protein/ml, were used. Mycoplasma strains were chosen am ong closely related species of the ''mycoides cluster'', M. capricolum , Group 7 of Leach, M. mycoides mycoides LC, M. mycoides mycoides SC, M. mycoides capri, as well as among species that are isolated from goa t lungs, M. arginini, M. ovipneumoniae, M. putrefaciens, M. agalactiae . Out of 60 mAbs, 4 were chosen to build an identification test for my coplasmas of the ''mycoides cluster''. Controls showed that accurate i dentification could be hampered by antigenic heterogeneity within the M. capricolum species. One mAb was used for the direct detection of M. sp. F38 antigen in pleural fluid from goats suspected of CCPP. The se nsitivity of the test can be estimated at 0.5 mu g protein/ml. Compari son with isolation results show a 74% agreement between the two method s. The same mAb was used to build a blocking ELISA. This serological t est was Strictly specific for CCPP. It detects antibodies in sera of n aturally infected or artificially immunized animals while it remained negative with hyperimmune sera to related strains such as PG 50. Direc t antigen detection and blocking ELISA are tools that may enable a bet ter assessment of CCPP distribution.