Integron activity accelerates the evolution of antibiotic resistance



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Souque, Celia and Escudero García-Calderón, José Antonio and MacLean, Craig (2021) Integron activity accelerates the evolution of antibiotic resistance. eLife . ISSN 2050-084X

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Mobile integrons are widespread genetic platforms that allow bacteria to modulate the expression of antibiotic resistance cassettes by shuffling their position from a common promoter. Antibiotic stress induces the expression of an integrase that excises and integrates cassettes, and this unique recombination and expression system is thought to allow bacteria to ‘evolve on demand’ in response to antibiotic pressure. To test this hypothesis, we inserted a custom three-cassette integron into Pseudomonas aeruginosa and used experimental evolution to measure the impact of integrase activity on adaptation to gentamicin. Crucially, integrase activity accelerated evolution by increasing the expression of a gentamicin resistance cassette through duplications and by eliminating redundant cassettes. Importantly, we found no evidence of deleterious off-target effects of integrase activity. In summary, integrons accelerate resistance evolution by rapidly generating combinatorial variation in cassette composition while maintaining genomic integrity.

Item Type:Article
Subjects:Medical sciences > Medicine
Medical sciences > Medicine > Medical microbiology
Medical sciences > Veterinary > Microbiology
Medical sciences > Biology > Molecular biology
Medical sciences > Biology > Evolution
Medical sciences > Biology > Genetics
Medical sciences > Biology > Microbiology
ID Code:70807
Deposited On:28 Feb 2022 11:22
Last Modified:28 Feb 2022 11:23

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