What is a pathogen? Toward a process view of host-parasite interactions

Pierre-Olivier Methot , Samuel Alizon (1)

1 MIVEGEC-ETE - Evolution Théorique et Expérimentale

Until quite recently and since the late 19(th) century, medical microbiology has been based on the assumption that some micro-organisms are pathogens and others are not. This binary view is now strongly criticized and is even becoming untenable. We first provide a historical overview of the changing nature of host-parasite interactions, in which we argue that large-scale sequencing not only shows that identifying the roots of pathogenesis is much more complicated than previously thought, but also forces us to reconsider what a pathogen is. To address the challenge of defining a pathogen in post-genomic science, we present and discuss recent results that embrace the microbial genetic diversity (both within- and between-host) and underline the relevance of microbial ecology and evolution. By analyzing and extending earlier work on the concept of pathogen, we propose pathogenicity (or virulence) should be viewed as a dynamical feature of an interaction between a host and microbes.

Mots clés: disease; ecology; evolution; infection; process; virulence

Domaines: Evolution [q-bio.PE]; Microbiologie et Parasitologie; Modélisation et simulation; Systématique, phylogénie et taxonomie

Pierre-Olivier Methot, Samuel Alizon. What is a pathogen? Toward a process view of host-parasite interactions. Virulence, 2014, 5 (8), pp.775-85. ⟨10.4161/21505594.2014.960726⟩. ⟨hal-01567912⟩