title: Flow directs surface-attached bacteria to twitch upstream.
abstract: Bacteria inhabit a wide variety of environments in which fluid flow is present, including healthcare and food processing settings and the vasculature of animals and plants. The motility of bacteria on surfaces in the presence of flow has not been well characterized. Here we focus on Pseudomonas aeruginosa, an opportunistic human pathogen that thrives in flow conditions such as in catheters and respiratory tracts. We investigate the effects of flow on P. aeruginosa cells and describe a mechanism in which surface shear stress orients surface-attached P. aeruginosa cells along the flow direction, causing cells to migrate against the flow direction while pivoting in a zig-zag motion. This upstream movement is due to the retraction of type IV pili by the ATPase motors PilT and PilU and results from the effects of flow on the polar localization of type IV pili. This directed upstream motility could be beneficial in environments where flow is present, allowing bacteria to colonize environments that cannot be reached by other surface-attached bacteria.
authors: Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey, USA.
authors: Yi
authors: Y
authors: Shen
authors: Albert
authors: A
authors: Siryaporn
authors: Sigolene
authors: S
authors: Lecuyer
authors: Zemer
authors: Z
authors: Gitai
authors: Howard A
authors: HA
authors: Stone
mesh_terms: D036781:Fimbriae Proteins / Q000235:genetics / Q000502:physiology; D010861:Fimbriae, Bacterial / Q000737:chemistry / Q000502:physiology*; D017353:Gene Deletion; D046210:Microfluidic Analytical Techniques; D009068:Movement; D011550:Pseudomonas aeruginosa / Q000502:physiology*
chemical_list: C091957:PilU protein, Pseudomonas aeruginosa; D036781:Fimbriae Proteins