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12:32
Quantification of Plasmid-Mediated Antibiotic Resistance in an Experimental Evolution Approach
Published on: December 14, 2019
Hypermutability and compensatory adaptation in antibiotic-resistant bacteria
Gabriel G Perron1, Alex R Hall, Angus Buckling
1Department of Zoology, University of Oxford, United Kingdom. g.guimond-perron@imperial.ac.uk
The American Naturalist
|July 14, 2010
Summary
Mutator bacteria, which have higher mutation rates, can develop antibiotic resistance faster and overcome its fitness costs. This explains why antibiotic resistance persists in mutator populations even without antibiotic pressure.
Area of Science:
- Microbiology
- Evolutionary Biology
- Genetics
Background:
- Hypermutable (mutator) bacteria are linked to antibiotic resistance.
- Mutators may compensate for resistance-related fitness costs, aiding resistance maintenance without selection.
Purpose of the Study:
- To investigate if mutator bacteria compensate for antibiotic resistance fitness costs more effectively than wild-type bacteria.
- To determine the impact of mutator genotypes on the maintenance of antibiotic resistance in *Pseudomonas aeruginosa*.
Main Methods:
- Experimental evolution using wild-type and mutator *Pseudomonas aeruginosa* populations.
- Competition assays between antibiotic-resistant and antibiotic-susceptible bacteria in both mutator and wild-type backgrounds.
- Monitoring of antibiotic resistance levels in the absence of antibiotic selection.
Main Results:
- Mutator bacteria evolved antibiotic resistance more rapidly than wild-type bacteria.
- Mutator bacteria demonstrated superior compensation for the fitness costs associated with antibiotic resistance.
- Antibiotic resistance was maintained at high levels in mutator populations but diminished in wild-type populations without antibiotic selection.
Conclusions:
- Mutator genotypes facilitate faster acquisition and better compensation of antibiotic resistance fitness costs.
- The enhanced fitness compensation in mutators explains the persistence of antibiotic resistance in chronic infections.
- Selection for compensatory mutations in mutators may contribute to the high prevalence of both mutator bacteria and antibiotic resistance in clinical settings.
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