Incomplete immunity in a natural animal-microbiota interaction selects for higher pathogen virulence

• DOI: 10.1016/j.cub.2024.02.015
• Publication Date: 2024-03-01T15:27:12Z
• Authors: Kim L. Hoang; Timothy D. Read; Kayla C. King
• Keywords: Evolution, Molecular; 0303 health sciences; 03 medical and health sciences; Virulence; Bacteria; Report; Microbiota; Animals; Biological Evolution

Incomplete immunity in recovered hosts is predicted to favor more virulent pathogens upon re-infection the population.1Fleming-Davies A.E. Williams P.D. Dhondt A.A. Dobson A.P. Hochachka W.M. Leon Ley D.H. Osnas E.E. Hawley D.M. host favors evolution of virulence an emergent pathogen.Science. 2018; 359: 1030-1033Crossref PubMed Scopus (40) Google Scholar The microbiota colonizing animals can generate a similarly long-lasting, partial immune response, allowing for infection but dampened disease severity.2Hoang K.L. King K.C. Symbiont-mediated priming through evolutionary lens.Microbiology. 2022; 168: 1-11Crossref (2) We tracked trajectories widespread pathogen (Pseudomonas aeruginosa), experimentally passaged populations nematodes immune-primed by natural member (P. berkeleyensis). This bacterium induce genes regulated mitogen-activated protein kinase (MAPK) signaling pathway effective at conferring protection against pathogen-induced death despite infection.3Montalvo-Katz S. Huang H. Appel M.D. Berg M. Shapira Association with soil bacteria enhances p38-dependent resistance Caenorhabditis elegans.Infect. Immun. 2013; 81: 514-520Crossref (94) Across populations, this incomplete selected than twice as likely kill those evolved non-primed (i.e., naive) or immune-compromised (mutants knockout MAPK ortholog) control populations. Despite higher virulence, molecular was slow and constrained. In comparison, evolving were characterized substantial genomic differentiation attenuated virulence. These findings directly attribute induced from significant force shaping dynamics novel infectious diseases.