Faculty Seminar: Mechanomicrobiology: how bacteria sense and respond to forces

When initiating infection or colonizing their environment, bacteria experience mechanical forces on surfaces, in flow, or within elastic materials. Despite their ubiquity, how mechanics shape bacterial physiology and behavior is unknown. Pseudomonas aeruginosa is a widespread opportunistic pathogen whose antibiotic resistance is rising at an alarming pace. P. aeruginosa is acutely adapted to life on surfaces: it uses surface-specific motility, injects pathogenic effectors into host cells upon contact, and forms biofilms on abiotic and biological materials. To investigate how mechanics potentiate P. aeruginosa’s surface adaptation arsenal, my lab has developed novel methodologies allowing to mechanically interrogate bacteria at multiple scales. I will first present how mechanics impact surface-specific twitching motility at the single cell level and biofilm morphogenesis at the multicellular level. Then, I will show that P. aeruginosa controls twitching in response to mechanical input. At the molecular scale, I will particularly emphasize the mechanosensory function of retractile filaments called type IV pili. Finally, I will discuss the ramifications of bacterial mechanobiology in the context of P. aeruginosa infections.

Alex Persat is currently Tenure Track Assistant Professor at the EPFL Global Health Institute and the Institute for Bioengineering. He obtained his BSc at Ecole Polytechnique, Paris and his MSc and PhD at Stanford University in Chemical and Mechanical Engineering respectively. After a postdoc in the department of Molecular Biology at Princeton University, he started his lab at EPFL where he combines engineering and microbiology approaches to understand how bacteria sense, respond and adapt to their mechanical environment.

This seminar is part of the evaluation of Dr Persat for the promotion to associate professor.