Enzyme-linked immunosorbent assay for detection of Mycoplasma californicum-specific antibody in bovine serum: optimization of assay determinants and control of serologic cross-reactions.
An enzyme-linked immunosorbent assay (ELISA) was adapted to detect Mycoplasma californicum-specific antibodies in bovine serum. Cross-reactive antibody was found in the M californicum-positive reference serum when assayed against each of 7 solid-phase antigens of heterologous mycoplasma species. Cross-reactivity was further demonstrated by inhibition of ELISA reactivity to M californicum solid-phase antigen by incubation of sera with antigen suspensions of each heterologous species. Incubation of test sera with a cross-reacting antigen mixture containing equal proportions of the 7 cross-reactive mycoplasmas was used to minimize cross-reactivity in the M californicum-specific ELISA. Specificity of antibody reactivity to M californicum, as measured by ELISA, was determined by enzyme-linked immunosorbance inhibition, in which sera were incubated with M californicum antigen suspensions before determining ELISA reactivity to M californicum solid-phase antigen. Seropositive and suspect sera (n = 55) were obtained from 3 dairies that had bacteriologically verified epizootics of M californicum mastitis. The percentage of inhibition demonstrated in enzyme-linked immunosorbance inhibition was determined for each serum. Inhibition percentages below the 15th percentile (61% inhibition) of this distribution were classified as nonspecific.
D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D000918:Antibody Specificity; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis*; D003429:Cross Reactions; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D008414:Mastitis, Bovine / Q000175:diagnosis*; D009174:Mycoplasma / Q000276:immunology*; D009175:Mycoplasma Infections / Q000175:diagnosis / Q000662:veterinary*
D000907:Antibodies, Bacterial