[Isolation and characterization of the three first strains of "Legionella pneumophila" found in France (author's transl)].

The technical methods of culture and identification of the three first strains isolated in France of Legionella pneumophila serogroup 1, are described. In two patients, bacilli were seen by the direct fluorescent antibody (DFA) method, either during the course of the disease (case 1) or at postmortem examination (case 3). The causal strain was cultivated after guinea-pig inoculation or directly from either bronchial aspirate or postmortem lung. Identification of L. pneumophila required the determination of metabolic characteristics, DFA characterization and cellular-fatty acids analysis (by gas-liquid chromatography). In the three cases, a significant seroconversion was detected by indirect fluorescent antibody test. The relative value of the differnt methods of diagnostic methos is discussed and the importance of strain isolation is emphasized.