Amoebae as a host for Legionella replication

Abstract

Legionella pneumophila (L. pneumophila) is a gram-negative bacterium found ubiquitously in natural water sources where it replicates within amoebae, such as Acanthamoeba castellanii (A. castellanii). The evolution in amoebal hosts allows L. pneumophila to ‘accidentally’ infect human lungs after inhalation of aerosols containing L. pneumophila. In both human macrophages and amoebae, L. pneumophila replicates intracellularly within a vacuole known as the Legionella containing vacuole (LCV) that avoids fusion with the endocytic pathway. Fundamental to this process is the translocation of over 330 proteins by L. pneumophila into host cells by the Dot/Icm type 4 secretion system. To date, only a..