Evaluation of an Immunodiffusion Test for the Detection of Antibodies to Brucella Abortusin Bovine Serum

Abstract

CONSIDERABLE attention has been paid to the selection of diagnostic procedures for differentiation of antibodies resulting from vaccination of cattle with Brucella abortus, strain 19, from those resulting from natural infection (Yuskovets, 1956;Anderson et al., 1964;Rose and Amerault, 1964;Schimmel and Erler, 1967). Relatively less attention has been given to the problems in diagnosis arising from the use of Br. abortus strain-45/20 adjuvant vaccine. This vaccine is weakly agglutinogenic but gives rise to significant titres of antibodies active in the complement fixation (CF) and antiglobulin tests. Although, in most cases, the antibody titres in all of these tests decline to insignificant levels within 1 yr of vaccination, some animals show persistent titres sufficiently high to cause difficulties in the interpretation of diagnostic tests. Usually in these cases the CF test shows inconclusive or weakly positive reactions and the titres in the antiglobulin test are also raised.These problems are accentuated in herds in which strain 19 and strain 45/20 vaccines have been used. In such cases, agglutinins active in the serum agglutination (SA) and Rose Bengal plate (RBP) tests may also persist at significant levels for prolonged periods.Clearly, to resolve this situation, a supplementary test is needed that would enable features characteristic of either the vaccinated or the naturally infected state to be identified. A procedure of potential value in this situation is the immunodiffusion test. This has the advantage of enabling the reaction of specific antigenic components with their respective antibodies to be identified. Thus, antibodies to components specific either to the infected or the vaccinated state could, hypothetically, be identified.In the present study, a comparison of an immunodiffusion test with standard diagnostic tests was made on serum samples from unvaccinated cattle, from cattle vaccinated with strain 19 or strain 45/20, and from cattle known to be infected with virulent Br. abortus strains. MATERIALS AND METHODS Brucella

Antibody response to antigens distinct from smooth lipopolysaccharide complex in Brucella infection

“…Soluble antigens containing S-LPS and other components have been employed in immunoprecipitation tests with a limited number of sera from infected cattle (2,3,13,20 mixture obtained from rough-strain Brucella melitensis B115 which lacked S-LPS and was characterized as a protein-rich preparation (14) was shown to produce precipitin lines with sera from infected humans (9) and cattle (R. Diaz, unpublished data), suggesting the potential importance of these non-S-LPS antigens in the diagnosis of brucellosis.…”

Counter‐immunoelectrophoresis for the detection of Brucella antigen and antibodies in the diagnosis of brucellosis in buffaloes

“…It seems that the antibodies directed against internal protoplasmic antigens gave positive reaction in CIE and AGPT in the absence of antibodies to surface antigen detected by SAT and RBPT. Nevertheless, precipitating antibodies may be present in the absence of agglutinating activity (Corbel et al 1973b; Muhammed et al 1980). From this limited study, it is reasonable to conclude that CIE can successfully be employed for the detection of brucella antigen in fetal stomach contents and antibodies in serum samples of buffaloes.…”

Isolation and properties of an RNA fraction present inBrucellaculture supernatants

“…Immunodiffusion tests against antisera to Brucella spp. were done according to Corbel (1973). Similar diffusion tests using 1% (w/v) solutions oflysozyme, trypsin, ribonuclease, poly-L-lysine, poly-L-arginine, poly-L-glutamic acid, poly-D-glutamic acid and normal rabbit and bovine sera were performed at 4 0C.…”