Pathogenicity and Virulence of : Intracellular replication and host response.

Bacteria of the genus are natural pathogens of amoebae that can cause a severe pneumonia in humans called Legionnaires' Disease. Human disease results from inhalation of -contaminated aerosols and subsequent bacterial replication within alveolar macrophages. pathogenicity in humans has resulted from extensive co-evolution with diverse genera of amoebae. To replicate intracellularly, generates a replication-permissive compartment called the -containing vacuole (LCV) through the concerted action of hundreds of Dot/Icm-translocated effector proteins. In this review, we present a collective overview of pathogenicity including infection mechanisms, secretion systems, and translocated effector function. We also discuss innate and adaptive immune responses to , the implications of genome diversity and future avenues for the field.