Understanding and predicting the evolution of antibiotic resistance in human infection

Antibiotics are our main defence against bacterial infections, but rising levels of resistance risks rendering antibiotics ineffective. We do not yet understand how resistance evolves within human infections, or why resistance emerges in some individuals but not in others. Clinical trials for antibiotics offer a powerful way to answer this question because they are, in effect, large experiments where the evolution of resistance can be observed in real-time in humans. To explore why resistance emergence varies between patients we will study the evolutionary processes leading to resistance in two clinical trials: during the trials, patients with long-term bacterial infections were treated with an antibiotic, and resistance emerged in around half of the patient infections. We will then use this understanding of bacterial evolution to develop tools that help doctors predict which patients are at risk of their infection developing resistance, allowing better treatment choices and more sustainable use of antibiotics.