PHYSICS COLLOQUIUM
California State University Long Beach

Monday, November 6, 2017
11:15 am in PH1-223

(Refreshments served at 10:45am in HSCl-224)
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Force Sensing by Bacteria
Prof. Albert Siryaporn
Department of Physics and Astronomy
Department of Biology & Biochemistry
University of California Irvine

My lab explores how bacteria detect and respond to mechanical forces. During the course of an infection, bacteria encounter a variety of mechanical forces such as adhesive forces during contact with the host cells that they infect and shear stresses in fluidic environments. We have developed a biophysical approach to explore how bacteria interpret mechanical cues to detect the presence of host cells and to guide the expansion of large bacterial populations within host organisms. In particular, we found that the pathogen Pseudomonas aeruginosa detects the presence of hosts using a mechano-sensitive mechanism, akin to a bacterial sense of touch. This response activates virulence and consequently P. aeruginosa, unlike other pathogens, relies on mechanical input rather than exclusively on chemical signals for infection. This model provides a long-sought explanation for understanding how P. aeruginosa can infect a broad range of hosts including humans, animals and plants. The ubiquity and diversity of mechanical forces in all aspects of a bacterium’s life have far-reaching consequences that we are just beginning to comprehend.