Specificity of the skin delayed-type hypersensitivity test in brucellosis free cattle tested with a Brucella allergen.

A study was conducted to determine possible nonspecific skin delayed-type hypersensitivity (SDTH) test reactions in cattle tested with a Brucella allergen. Cattle (n = 14) experimentally inoculated with microorganisms known serologically to cross-react with Brucella and cattle (n = 549) from Brucella free herds were tested serologically and with the SDTH test. The increase in skinfold thickness at the injection site of the allergen was measured to the nearest mm with calipers 48 hours after injection.

Enzyme immunoassay using mouse monoclonal anti-bovine antibodies for the detection of Brucella abortus antibodies in cow milk.

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).

Evaluation of an ELISA for the diagnosis of experimentally induced and naturally occurring Leptospira hardjo infections in cattle.

An enzyme-linked immunosorbent assay (ELISA) for the diagnosis of Leptospira interrogans serovar hardjo (hardjo) infection in cattle was compared with the microscopic agglutination test (MAT). Glutardialdehyde was used in the ELISA to couple sonicated hardjo antigen to the microtiter plate. Mouse monoclonal anti-bovine IgG1 coupled to peroxidase was used as conjugate.