Enzyme Immunoassay Using Mouse Monoclonal Anti‐bovine Antibodies for the Detection of Brucella abortus Antibodies in Cow Milk

Abstract

Summary Individual milk samples and artificially constructed tank milk samples from cows with naturally occurring brucellosis were examined by the enzyme‐linked immunosorbent assay (ELISA) using sonicated B. abortus S‐99 antigen, and mouse monoclonal anti‐bovine IgM, IgA, and IgG1 conjugates. ELISA results were compared with the results of the milk ring test using either 1 ml milk (MRT‐1) or 8 ml milk (MRT‐8). The ELISA using mouse monoclonal anti‐bovine IgG1 conjugate was sensitive and specific. In testing individual milk samples and constructed tank milk samples containing milk with low titers in the MRT‐1 the ELISA was superior to the MRT‐1, and MRT‐8. In testing other milk samples, the ELISA was as sensitive or slightly less sensitive than the MRT‐8. From a total of 5,910 milk samples collected from cows free from brucellosis, only 24 (0.4 %) samples tested positive in the ELISA. All 500 tank milk samples collected from farms negative for brucellosis tested negative in the ELISA. We concluded that the ELISA is a good substitute for the MRT‐1 to detect antibodies against Brucella in milk from individual cows. When tank milk is tested for antibodies against Brucella, however, both the MRT‐8 and the ELISA should be used.

Isolation ofBrucella melitensisfrom an Arabian oryx (Oryx leucoryx)

“…Serological investigations were carried out. The qualitative card test (Brucelloslide‐Test; bioMérieux) was positive; a Brucella abortus serum agglutination test standardised against the international standard serum of Weybridge ( ID ‐Lelystad) was positive at 480 IU /ml; B abortus and Brucella melitensis complement fixation tests ( ID ‐Lelystad) were positive at more than 200 IU /ml; and a B abortus indirect elisa serological test (Bercovich and Taaijke 1990) was positive at 320 IU /ml. Retrospective card tests were also performed, showing that the animal had been positive in November 1999, but not in April 1999.…”

The use of skin delayed‐type hypersensitivity as an adjunct test to diagnose brucellosis in cattle: A review

“…The ELISA can be used for screening as well as for confirmation of brucellosis in both milk and serum. The assay has proven to be as specific and as sensitive as the MRT in detecting Brucella antibody in milk (10). However, its dependence on the type and concentration of lacteal immunoglobulin present in milk sometimes affects its efficacy to detect Brucella antibodies (10).…”

“…The assay has proven to be as specific and as sensitive as the MRT in detecting Brucella antibody in milk (10). However, its dependence on the type and concentration of lacteal immunoglobulin present in milk sometimes affects its efficacy to detect Brucella antibodies (10). Furthermore, the first week after parturition, when milk contains traces of colostrum, the ELISA may yield false-positive results (54,92).…”