Most species of Legionellaceae have been isolated from the environment and can be found in
natural waters, marine waters, cooling towers and spa pool waters.
All Legionella species are
potentially pathogenic towards humans and legionellosis is transmitted via aerosols.
Culture
isolation of Legionellae from recreational and environmental waters is generally the method of
choice, although some isolates grow only slowly and can be inhibited by the growth of other
competing organisms.
Details of sampling, detection and enumeration are described
elsewhere (91).
Methods usually involve concentration by membrane filtration, followed by acid
and heat pre-treatment and culture on selective media.
