Detection of brucellae and their antibodies by fluorescent antibody and agglutination tests.

The laboratory diagnosis of brucellosis often is delayed because of the difficulty of isolating and growing the organisms. Once isolated in pure culture, the brucellae can be identified by the agglutination test, the standard method requiring 48 hr at 37 C. Similarly, antibodies from patients with brucellosis can be detected with antigens of brucellae. It was postulated that fluorescent antibody techniques would facilitate the detection of smaller numbers of brucellae much earlier, since relatively heavy concentrations of the organisms in pure culture would not be required. Fluorescent antibody investigations with other bacteria have indicated that well defined conditions for producing antibody which will be specific for the homologous organism must be set up and the conditions of staining and interpretation of the tests carefully investigated (Moody, Goldman, and Thomason, 1956; Thomason, Moody, and Goldman, 1956; Moody, Ellis, and Updyke, 1958; Cherry and Freeman, 1959; Winter and Moody, 1959a, b; Moody and Winter, 1959). It has not been possible to predict reliably the specificity and suitability of a given antiserum as a fluorescent antibody reagent merely because it is satisfactory as a reagent in the agglutination or precipitin test. The present report describes conditions whereby fluorescent antibody reagents for the laboratory diagnosis of brucellosis can be prepared and used to detect either brucellae or their antibodies in serum.