Enzyme-linked immunosorbent assay (ELISA) for titration of antibodies against Brucella abortus and Yersinia enterocolitica.

An enzyme linked immunosorbent assay (ELISA) using phenolwater extracted lipopolysaccarides as antigen was used for detection and quantitation of antibodies against Brucella and Yersinia bacteria in rabbit antisera. ELISA was found to be from ten to hundred-fold more sensitive than the commonly used tube agglutination assay (Widal). In addition, both direct and inhibition assays using ELISA revealed antigenic differences between Brucella abortus and Yersinia enterocolitica O-group V, previously undetected in tube agglutination and complement fixation studies. These data raise the possibility of a sensitive and specific assay for detection of anti-Brucella antibodies in human sera.