Detection of Legionnaires disease bacteria by direct immunofluorescent staining

Abstract

Antisera and fluorescein isothiocyanate conjugates prepared for 5 strains of the Legionnaires bacteria were tested in homologous and heterologous staining reactions with 10 isolates of the organism from patients in 7 geographic areas. The strains were related but not identical as judged by the results of direct immunofluorescence staining. The conjugates were successfully used to detect Legionnaires disease bacteria in Formalin-fixed lung scrapings, in histological sections and in fresh lung tissue obtained at biopsy or autopsy. The labeled antibodies are valuable for staining suspected cultures of the bacterium and for searching for the source of these organisms in soil, water and other environmental niches. The reagents are highly specific for detecting the Legionnaires organism in clinical specimens.