MEMBRANE POLYSACCHARIDES OF BRUCELLA ABORTUS 1119-3, IN AGAR GEL IMMUNODIFUSION TEST, IN DIAGNOSIS OF BRUCELLOSIS ON VACCINATED HEIFERS (Bl9)

ABSTRACT

The serological profiles of 33 female bovines, vaccinated at three to eight months of age with the B19 standard strain of Brucella abortus, were evaluated by agar gel immunodifusion test, comparatively to plate agglutination, tube agglutination, rose bengal plate and mercaptoethanol tests, over a period of 24 months. For the immunodifusion test, polysaccharide extract obtained from the sample B. abortus 1119-3, was used as antigen. Only one (3.0%) animal presented precipitate reaction in the immunodifusion test on the 14th day after vaccination. On the 28th day after immunization, 15 (45.4%) animais revealed reaction in the immunodifusion, with the sarne amount on the 42nd experimental day. On the 56th day after vaccination, three (9.1%) animais were observed positive in the immunodifusion and one (3.0%) with weak-positive reaction, that stayed detectable on the 91th and 119th days after vaccination; although the other animais were negative since the 91th day after the immunization. Maximum leveis of antibodies detected reached by the plate agglutination, tube agglutination and mercaptoethanol tests were found between the 14th and the 42nd day, with regular and continuous decline after this period, and together with rose bengal plate test, were considered negative around ten months after vaccination. Among the tests used, the agar gel immunodiffusion assay containing polysaccharide antigens presented greater precocity in the absence of positive reactions (five months after vaccination).

KEY WORDS:
Bovine brucellosis; immunodiffusion test; polysaccharide antigen; agglutination tests; B19