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Published on: January 12, 2017
Predation on multiple trophic levels shapes the evolution of pathogen virulence
Ville-Petri Friman1, Carita Lindstedt, Teppo Hiltunen
1Department of Biological and Environmental Science, Centre of Excellence in Evolutionary Research, University of Jyväskylä, Jyväskylä, Finland. vifriman@jyu.fi
Plos One
|August 27, 2009
Summary
Predation on bacteria by protozoa can reduce pathogen virulence. Host defense evolution is also influenced by predation, showing complex ecological interactions shape host-pathogen dynamics.
Area of Science:
- Ecology
- Evolutionary Biology
- Microbiology
Background:
- Pathogen virulence traditionally co-evolves with host resistance.
- Ecological communities involve complex interactions affecting host-pathogen dynamics.
- Predation is a significant ecological factor that can influence evolutionary trajectories.
Purpose of the Study:
- To investigate how predation pressure affects pathogen virulence.
- To examine the impact of predation on host immune defense evolution.
- To understand the role of interspecific interactions in shaping host-pathogen co-evolution.
Main Methods:
- Experimental evolution of the bacterial pathogen Serratia marcescens under predation by Tetrahymena thermophila.
- Assessing changes in bacterial virulence against the host moth Parasemia plantaginis.
- Evaluating host survival in relation to immune defense and anti-predator signaling (warning coloration).
Main Results:
- Predation by T. thermophila decreased S. marcescens virulence, likely due to trade-offs between anti-predatory and virulence traits.
- Host survival was inversely related to warning signal size when infected with highly virulent bacteria, suggesting an immune defense-signaling trade-off.
- This trade-off was less apparent with less virulent bacterial strains, indicating pathogen virulence modulates host defense allocation.
Conclusions:
- Predation acts as an indirect driver of pathogen virulence evolution.
- Ecological interactions, such as predation, are crucial in shaping host immune defense.
- Pathogen virulence is a product of both evolutionary history and current ecological pressures.
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