title: Success of a suicidal defense strategy against infection in a structured habitat.
abstract: Pathogen infection often leads to the expression of virulence and host death when the host-pathogen symbiosis seems more beneficial for the pathogen. Previously proposed explanations have focused on the pathogen's side. In this work, we tested a hypothesis focused on the host strategy. If a member of a host population dies immediately upon infection aborting pathogen reproduction, it can protect the host population from secondary infections. We tested this "Suicidal Defense Against Infection" (SDAI) hypothesis by developing an experimental infection system that involves a huge number of bacteria as hosts and their virus as pathogen, which is linked to modeling and simulation. Our experiments and simulations demonstrate that a population with SDAI strategy is successful in the presence of spatial structure but fails in its absence. The infection results in emergence of pathogen mutants not inducing the host suicide in addition to host mutants resistant to the pathogen.
authors.affiliation: Department of Medical Genome Sciences, Graduate School of Frontier Sciences, University of Tokyo, Tokyo 108-8639, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Fukuyo
authors.forename: Akira
authors.initials: A
authors.lastname: Sasaki
authors.forename: Ichizo
authors.initials: I
authors.lastname: Kobayashi
mesh_terms: D001483:Base Sequence; D017753:Ecosystem; D004926:Escherichia coli / Q000302:isolation & purification / Q000472:pathogenicity / Q000502:physiology*; D054884:Host-Pathogen Interactions; D017053:Infection Control; D008962:Models, Theoretical; D008969:Molecular Sequence Data; D014774:Virulence