Abstract

Most of our knowledge about bacterial biology comes from well-mixed flasks but in natural and clinical settings bacteria often experience spatiotemporal gradients of multiple factors, ranging from nutrients and waste products to antimicrobials. By virtue of favouring the study of homogenous cultures, we know little about how bacteria respond to spatially heterogenous environments and how such heterogeneity affects bacterial adaptation. In this talk, I will discuss how bacteria control their motility and evolve in antibiotic landscapes. In the first part of talk, I will show that biofilm bacteria actively move towards antibiotics when exposed to spatial gradients of antibiotics in microfluidic experiments, and I will explain why they have such a perplexing motile behaviour. The devil is in microbial ecology. In the second part of the talk, I will use numerical and analytical results to show that bacterial motility governs the evolution of antibiotic resistance. In particular, I will clarify why cell motility can accelerate and decelerate the rate of bacteria adaptation in antibiotic landscapes. Again, the devil is in microbial ecology. I will argue that we need to appreciate microbial stress behaviour, ecology and evolution to improve how we respond to microbes and their impacts on us.