Characterization of Legionella pneumophila pmiA, a gene essential for infectivity of protozoa and macrophages.

The ability of Legionella pneumophila to cause pneumonia is dependent on intracellular replication within alveolar macrophages. The Icm/Dot secretion apparatus is essential for the ability of L. pneumophila to evade endocytic fusion, to remodel the phagosome by the endoplasmic reticulum (ER), and to replicate intracellularly.