Stevens, Emily J, Li, Jingdi D, Hector, Tobias E, Drew, Georgia C, Hoang, Kim, Greenrod, Samuel TE, Paterson, Steve 
ORCID: 0000-0002-1307-2981 and King, Kayla C
(2025)
Within-host competition causes pathogen molecular evolution and perpetual microbiota dysbiosis.
The ISME journal, 19 (1).
wraf071-.
ISSN 1751-7362, 1751-7370
Abstract
Pathogens newly invading a host must compete with resident microbiota. This within-host microbial warfare could lead to more severe disease outcomes or constrain the evolution of virulence. By passaging a widespread pathogen (Staphylococcus aureus) and a natural microbiota community across populations of nematode hosts, we show that the pathogen displaced microbiota and reduced species richness, but maintained its virulence across generations. Conversely, pathogen populations and microbiota passaged in isolation caused more host harm relative to their respective no-host controls. For the evolved pathogens, this increase in virulence was partly mediated by enhanced biofilm formation and expression of the global virulence regulator agr. Whole genome sequencing revealed shifts in the mode of selection from directional (on pathogens evolving in isolation) to fluctuating (on pathogens evolving in host microbiota). This approach also revealed that competitive interactions with the microbiota drove early pathogen genomic diversification. Metagenome sequencing of the passaged microbiota shows that evolution in pathogen-infected hosts caused a significant reduction in community stability (dysbiosis), along with restrictions on the co-existence of some species based on nutrient competition. Our study reveals how microbial competition during novel infection could determine the patterns and processes of evolution with major consequences for host health.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | Animals, Caenorhabditis elegans, Biofilms, Staphylococcus aureus, Evolution, Molecular, Virulence, Host-Pathogen Interactions, Microbiota, Dysbiosis, Whole Genome Sequencing |
| Divisions: | Faculty of Health and Life Sciences Faculty of Health and Life Sciences > Institute of Infection, Veterinary and Ecological Sciences |
| Depositing User: | Symplectic Admin |
| Date Deposited: | 24 Apr 2025 09:43 |
| Last Modified: | 22 May 2025 09:31 |
| DOI: | 10.1093/ismejo/wraf071 |
| Open Access URL: | https://doi.org/10.1093/ismejo/wraf071 |
| Related Websites: | |
| URI: | https://livrepository.liverpool.ac.uk/id/eprint/3191594 |
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