Setting up and monitoring an infection of Dictyostelium discoideum with mycobacteria.

Mycobacterium marinum is the causative agent of fish and amphibian tuberculosis in the wild. It is a genetically close cousin of Mycobacterium tuberculosis, and thereby the infection process remarkably shares many of the hallmarks of M. tuberculosis infection in human, at both the cellular and organism levels. Therefore, M. marinum is used as a model for the study of mycobacterial infection in various host organisms. Recently, the Dictyostelium-M. marinum system has been shown to be a valuable model that recapitulates the main features of the intracellular fate of M. marinum including phagosome maturation arrest, as well as its particular cell-to-cell dissemination mode. We present here a "starter kit" of detailed methods that allows to establish an infection of Dictyostelium with M. marinum and to monitor quantitatively the intracellular bacterial growth.