Exploring marine AMoebae and their endosymbionts as an environmental intracellular ADAPTive niche for pathogen emergence


Labex Cemeb (2018-2019)
Project leader: Guillaume Charrière
Free-living amoebae are bacteria predators that feed by phagocytosis. Under this selective pressure some bacteria have evolved strategies of resistance to predation and behave as facultative or obligatory endosymbionts. Among the diversity of amoeba endosymbionts that have been described in freshwaters, a majority belongs to clades that contain known pathogens for humans and other metazoans, including Legionnellales, Mycobateriae and Chlamydiae. Recently a report described for the first time two amoebae endosymbionts from marine isolates that belong to the Legionellales. In addition, we found that some Vibrionaceae can behave as facultative intracellular pathogens and resist to predation by marine amoebae. Hence some pathogens may emerge by acquiring resistance and virulence traits under selection by amoebae. Amoebae endosymbionts could then represent both a subset of potential pathogens as well as a genetic reservoir of resistance and virulence factors. Here, we propose to investigate the untapped diversity of free-living amoebae endosymbionts in marine environments to characterize this potential adaptive niche for emerging pathogens.


Examples of the diversity of the morphotypes of amoebas isolated in marine environment during the project VibrAm © E. Robino
Partner 1 - UMR 5244 IHPE: Guillaume Charrière, Etienne Robino, Sandra Le Buissonnais, Angélique Perret
Partner 2 - UMR 9190 MARBEC: Jean-Christophe Auguet
Partner 3 - UMR 5290 MIVEGEC : Olivier Duron, Marie Buysse