Doctorat Université de Poitiers

Responsabilités

Thèmes de Recherche

Interactions entre amibes libres et microorganismes dans les environnements hydriques

Les amibes libres sont des microorganismes eucaryotes unicellulaires, omniprésents dans les environnements hydriques naturels et anthropiques. Les amibes libres jouent un rôle important de régulation des populations de microorganismes dans divers environnements, se nourrissant de ces derniers par un mécanisme de phagocytose. La pression de sélection exercée par ce phénomène de prédation a favorisé à de multiples reprises l’adaptation de certains microorganismes (principalement bactériens) à un mode de vie intracellulaire. Cette adaptation, intimement liée au développement de la résistance à la phagocytose, représente non seulement un terrain propice pour l’étude des mécanismes favorisant la mise en place des symbioses, mais également pour l’étude des bactéries potentiellement pathogènes pour l’homme.

Nos travaux s’intéressent à la caractérisation des communautés amibiennes dans les environnement hydriques (réseaux d’eau potable et systèmes naturels), ainsi que l’ensemble des microorganismes qui leur sont associés (bactéries, virus, eucaryotes). Un intérêt particulier est porté sur les interactions entre amibes libres et mycobactéries non tuberculeuses, ainsi que sur les interactions entre amibes libres et bactéries du phylum Dependentiae (TM6).

Mots-clés (5)

Amibes, Eau, Interactions hôte-microorganisme, TM6, Mycobactéries

Publications représentatives (5)

1. Delafont, V., Brouke, A., Bouchon, D., Moulin, L., and Héchard, Y. (2013) Microbiome of free-living amoebae isolated from drinking water. Water Res. 47: 6958–6965.
2. Delafont, V., Mougari, F., Cambau, E., Joyeux, M., Bouchon, D., Héchard, Y., and Moulin, L. (2014) First Evidence of Amoebae–Mycobacteria Association in Drinking Water Network. Sci. Technol. 48: 11872–11882.
3. Delafont, V., Samba-Louaka, A., Bouchon, D., Moulin, L., and Héchard, Y. (2015) Shedding light on microbial dark matter: a TM6 bacterium as natural endosymbiont of a free-living amoeba. Microbiol. Rep. 7: 970–978.
4. Delafont, V., Bouchon, D., Héchard, Y., and Moulin, L. (2016) Environmental factors shaping cultured free-living amoebae and their associated bacterial community within drinking water network. Water Res. 100: 382–392.
5. Delafont, V., Samba-Louaka, A., Cambau, E., Bouchon, D., Moulin, L., and Héchard, Y. (2017) Mycobacterium llatzerense, a waterborne Mycobacterium, that resists phagocytosis by Acanthamoeba castellanii. Rep. 7: 46270.

Assistant Professor

I obtained a PhD in molecular Microbiology in 2015, at the University of Poitiers, under the supervision of Prof. Yann Héchard, Prof. Didier Bouchon and Dr. Laurent Moulin. I moved to the University of Vienna in 2016, to start a Marie Sklodowska-Curie Action (MSCA) funded postdoc, to join Matthias Horn’ lab at the Division of Microbial Ecology to work on symbioses involving amoebae. I integrated the EBI unit in September 2017, in order to continue my work on amoebae and their interactions with other microorganisms.

Interactions between free-living amoebae and other microorganisms in hydric environments.

Free-living amoebae (FLA) are unicellular eukaryotes, ubiquitous in natural and man-made water environments. In these environments, FLA play important roles in regulating microbial populations, as they feed on bacteria and other small eukaryotes by a mechanism involving ingestion by phagocytosis.It is thought that this predatory pressure favoured – on multiple occasion – the adaption of several microorganisms (mainly bacteria) to the intracellular lifestyle, by stimulating the arising of resistance mechanisms against phagocytosis.

Thus, we aim to study FLA and their associations with microorganisms, as it stands out as pertinent model not only for better understanding the establishment of symbioses, but also for decrypting mechanisms employed by several bacterial pathogens thriving within eukaryotic cells.

We are also interested in the characterisation of FLA communities’ dynamics in hydric environments (e.g. drinking water systems, naturals systems), together with the whole consortium of FLA-associated microorganisms, including bacteria, viruses and other eukaryotes. We give a particular focus on interactions between FLA and nontuberculous mycobacteria, as well as on interactions involving FLA and member of the Dependentiae (TM6) bacterial phylum.

 Keywords:

Amoebae; Water; host-microbe interactions, Dependentiae, Mycobacteria