Detection of antibodies to legionnaires disease organism by microagglutination and micro-enzyme-linked immunosorbent assay tests

Abstract

Microagglutination and micro-enzyme-linked immunosorbent assay (ELISA) tests with easily prepared, safe, heat-killed antigens for detecting [human] antibodies to the legionnaires disease organism were developed. A safranin-stained whole-cell antigen is used in the microagglutination test and a simply prepared soluble antigen is used in the micro-ELISA tests. The microagglutination test detected elevated titers in 97.2% of the sera from patients with legionnaries disease. Three variations of the micro-ELISA test with anti-human immunoglobulin G, immunoglobulin M, and Fab peroxidase-labeled conjugates revealed elevated titers with 74.3, 82.9 and 88.6% of the sera, respectively. The microagglutination and the micro-ELISA tests used in combination detected 100% of the elevated titers.