Legionella colonies on agar plates

Legionella are the causative agents of the Legionnaires’ disease (lung infection). These bacteria are growing in water distribution systems and infection is produced by inhalation of contaminated aerosols. Fifty-eight different species have been described until Y2012 but 90% of infections are due to L. pneumophila. We thank Dr. Valeria Gaia (Cantonal Institute of Microbiology, Bellinzona, Switzerland, ) for some strains of Legionella presented in