Investigating the evolutionary success of mcr-1, the first mobile colistin resistance gene

Post-doc project

Genes on the move: the impact on integron activity on antibiotic resistance evolution

PhD Project
Mobile integrons are fascinating clinically relevant drivers of antibiotic resistance. Acting as genetic platforms, they allow bacteria to capture, express and re-order mobile antibiotic resistance gene cassettes, whose expression levels depend on their distance from the promoter, located at the integration site. Cassettes can be integrated and excised by the integrase enzyme, produced by the bacteria in time of stress.

It has been hypothesized that integrons allow bacteria to adapt quickly to changing antibiotic pressures by reshuffling the cassette order, and therefore their resistance levels, such that integrons provide ‘adaptation on demand’, but this hypothesis had never been properly tested. Using a custom three-cassette integron system, I investigated the evolutionary benefits provided by integron activity with a combination of experimental evolution and whole genome sequencing.

This first part of this project has already been published in eLife.

Why and when do bacteria take up DNA?

PhD Project