title: Flagella and pili-mediated near-surface single-cell motility mechanisms in P. aeruginosa.
abstract: Bacterial biofilms are structured multicellular communities that are responsible for a broad range of infections. Knowing how free-swimming bacteria adapt their motility mechanisms near a surface is crucial for understanding the transition from the planktonic to the biofilm phenotype. By translating microscopy movies into searchable databases of bacterial behavior and developing image-based search engines, we were able to identify fundamental appendage-specific mechanisms for the surface motility of Pseudomonas aeruginosa. Type IV pili mediate two surface motility mechanisms: horizontally oriented crawling, by which the bacterium moves lengthwise with high directional persistence, and vertically oriented walking, by which the bacterium moves with low directional persistence and high instantaneous velocity, allowing it to rapidly explore microenvironments. The flagellum mediates two additional motility mechanisms: near-surface swimming and surface-anchored spinning, which often precedes detachment from a surface. Flagella and pili interact cooperatively in a launch sequence whereby bacteria change orientation from horizontal to vertical and then detach. Vertical orientation facilitates detachment from surfaces and thereby influences biofilm morphology.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas, USA.
authors.forename: Jacinta C
authors.initials: JC
authors.lastname: Conrad
authors.forename: Maxsim L
authors.initials: ML
authors.lastname: Gibiansky
authors.forename: Fan
authors.initials: F
authors.lastname: Jin
authors.forename: Vernita D
authors.initials: VD
authors.lastname: Gordon
authors.forename: Dominick A
authors.initials: DA
authors.lastname: Motto
authors.forename: Margie A
authors.initials: MA
authors.lastname: Mathewson
authors.forename: Wiktor G
authors.initials: WG
authors.lastname: Stopka
authors.forename: Daria C
authors.initials: DC
authors.lastname: Zelasko
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Shrout
authors.forename: Gerard C L
authors.initials: GC
authors.lastname: Wong
mesh_terms: D018441:Biofilms; D002455:Cell Division; D002462:Cell Membrane / Q000378:metabolism*; D010861:Fimbriae, Bacterial / Q000378:metabolism*; D005407:Flagella / Q000378:metabolism*; D009068:Movement; D011550:Pseudomonas aeruginosa / Q000166:cytology* / Q000378:metabolism*