Comparison of different antigenic preparations for the detection of ovine serum antibodies against Brucella ovis by ELISA.
An enzyme-linked immunosorbent assay has been developed for the detection of antibodies against Brucella ovis using serum from control rams (Con-S), naturally infected rams (Inf-S), rams inoculated intravenously with B. ovis (IV-S) and rams vaccinated intramuscularly (IM-S). The serum was titrated by serial double dilutions from 1/25 to 1/25,600 against whole bacteria, B. ovis lipopolysaccharide and a detergent-extracted component of the outer membrane complex of B. ovis as antigens immobilised on microtitre plates. Sheep antibodies bound to antigen were assayed with rabbit anti-sheep gammaglobulin and alkaline phosphatase conjugated protein A. A high level of antibody activity against intact B. ovis cells was detected in Inf-S and IM-S. When lipopolysaccharide was the immobilised antigen, only IM-S yielded significant antibody activity. The component from detergent extracts of the outer membrane complex of B. ovis reacted best with serum (up to 1/6,400) from field-infected rams, while serum from vaccinated and intravenously inoculated rams registered significant titres up to a serum dilution of 1/800 and 1/200 respectively. These results indicate that ELISA is a very sensitive test but its value as a serodiagnostic procedure is dependent upon the choice of antigen used in the assay.
D000469:Alkaline Phosphatase / Q000276:immunology; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D002002:Brucella / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D007074:Immunoglobulin G / Q000276:immunology; D008297:Male; D011817:Rabbits; D012756:Sheep / Q000276:immunology*
D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D000469:Alkaline Phosphatase