Le 22 octobre 2020 à 11h
Marianne GROGNOT, Rowland Institute at Harvard University, USA
Lieu(x) : visioconférence, https://ecolepolytechnique.zoom.us/j/82795646501?pwd=UTVUeTJIQ1ZHK05mR0p2SFNOMXNlZz09
Contact : Guilhem Gallot
guilhem.gallot at polytechnique.edu
Flagellated bacteria swim by rotating one or several flagella; motility alone results in a random walk, but the flagella’s rotation can be influenced by an intracellular sensory system that enables cells to climb or descend chemical gradients, in a process called chemotaxis. Altogether, motility and chemotaxis allow a bacterium to navigate their environment, a critical ability from the level of host-pathogen interactions to geochemical fluxes.
While navigation abilities have been studied extensively in liquid for E. coli, much less attention has been devoted to the diversity of bacteria with different flagella, or to motility in viscous or porous environments that more closely mimic the complexity of natural habitats.
During this seminar, I will present a simple yet powerful chemotaxis assay that I developed in the Taute Lab, combining a recent high-throughput 3D tracking method with microfluidically created chemical gradients. We can directly quantify how well a population of bacteria climbs a gradient, in diverse environments, while simultaneously resolving 3D motility behavior, enabling unprecedented access to a mechanistic understanding and quantitative comparison of navigation strategies. I will highlight its use in diverse projects, interrogating how different bacteria navigate different environments. Finally, I will delve into my broader research interest, where I see such an assay as a first step into a multiscale understanding of bacterial pathogens navigation in the human host during early infection processes.