Legionella pneumophilia

Legionella pneumophilia is a gram - negative bacterium (cocco-bacillus) that has a natural habitat in water, moist soil and mud. It is not present in sea water because it is inhibited by sodium chloride. It grows best in warm water (temperature above 20 degrees C) but a temperature of 60° is considered bactericidal, although the bacteria will eventually return when the temperature is lowered. (1)

1. Legionnaires' disease. The control of legionella bacteria in water systems. Approved Code of Practice and Guidance, Health and Safety Executive