What is the natural habitat of Legionella bacteria?
Legionella organisms are readily found in natural aquatic bodies and some species have been recovered from soil. The organisms can survive in a wide range of conditions, including temperatures of 0 to 63o C, pH of 5.0 to 8.5, and dissolved oxygen concentrations of 0.2 to 15 ppm in water. Temperature is a critical determinant for Legionella proliferation. Colonization of hot water tanks is more likely if tank temperatures are between 40 and 50oC (104 to 122o F). Legionella and other microorganisms become attached to surfaces in an aquatic environment forming a biofilm. Legionella has been shown to attach to and colonize various materials found in water systems including plastics, rubber, and wood. Organic sediments, scale, and inorganic precipitates provide Legionella with a surface for attachment and a protective barrier. Interestingly, the growth of other environmental organisms is stimulated by organic sediment, which in turn leads to the formation of by-products that stimulate the g
