Evolution of Virulence in Emerging Epidemics

PLoS Pathogens

Thomas W. Berngruber¹  Rémy Froissart²  Marc Choisy³  Sylvain Gandon³ 

[1] Centre d'Ecologie Fonctionnelle et Evolutive (CEFE) - UMR 5175, Montpellier, France;Laboratoire Biologie & Génétique des Interactions Plantes-Parasites (BGPI), UMR 385 INRA-CIRAD-SupAgro, Campus international de Baillarguet, Montpellier, France;Laboratoire Maladies Infectieuses et Vecteurs : Ecologie, Génétique, Evolution et Contrôle (MIVEGEC), UMR 5290 CNRS-IRD-Université de Montpellier I-Université de Montpellier II, Montpellier, France

关键词: Viral evolution;    Pathogens;    Bacterial evolution;    Evolutionary immunology;    Bacteriophages;    Evolutionary theory;    Lysis (medicine);    Evolutionary genetics;   

DOI  :  10.1371/journal.ppat.1003209

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Theory predicts that selection for pathogen virulence and horizontal transmission is highest at the onset of an epidemic but decreases thereafter, as the epidemic depletes the pool of susceptible hosts. We tested this prediction by tracking the competition between the latent bacteriophage λ and its virulent mutant λcI857 throughout experimental epidemics taking place in continuous cultures of Escherichia coli. As expected, the virulent λcI857 is strongly favored in the early stage of the epidemic, but loses competition with the latent virus as prevalence increases. We show that the observed transient selection for virulence and horizontal transmission can be fully explained within the framework of evolutionary epidemiology theory. This experimental validation of our predictions is a key step towards a predictive theory for the evolution of virulence in emerging infectious diseases.

【 授权许可】

CC BY