[General and molecular ecology of Legionella].

The review is devoted to the general and molecular ecology of bacteria of the genus Legionella in natural and anthropogenic environments. Invasion of amoebae and infusoria by legionellae and their replication in these protozoa can be considered to be a pre-adaptation for invasion of the human immune system. Symbiosis of bacteria and protozoa as a promising model of cellular microbiology and the conception of bacterial ecological niches are discussed in relation to the low fidelity of most bacterial species to their habitats (biotopes). The necessity of elaboration of a similar conception for microbial consortia and associations is emphasized.