COMPARISON BETWEEN ENZYME-LINKED-IMMUNOSORBENT-ASSAY, DISC FILM INHIBITION AND COMPLEMENT-FIXATION TESTS FOR THE DIAGNOSIS OF MYCOPLASMA-BOVIS

A total of 1300 bovine field sera was tested by the Indirect ELISA, Co mplement Fixation (CF) and Disc Film Inhibition (DFIT) Tests, for the detection of Mycoplasma bovis infections by the determination of circu lating antibodies in naturally infected cattle. ELISA showed the highe st specificity (96%) for detection of antibody against M. bovis, when ELISA OD greater-than-or-equal-to 0.900 was considered as positive, te sting negative sera in DFIT, and considering CF titres of 1/40 as posi tive. For sensitivity evaluation, the highest sensitivity of ELISA (90 %) was obtained considering ELISA OD greater-than-or-equal-to 0.600 as positive, testing sera positive in DFIT, and considering CF titres of 1/40 as negative. The ELISA proved to be a sensitive and specific tes t for Mycoplasma bovis serodiagnosis. The immunoglobulin classes measu red by each of the tests under study are discussed.