Some bacteria use type IV pili to move along surfaces within a biofilm. (Biofilms are to viscous for bacteria to swim through with flagella.) The bacterium extends and anchors its pili. As the pili retract the bacterium is pulled forward. This enables the bacteria to drag themselves through biofilms on environmental surfaces with a twitching motility. This twitching motility alternates with a type-IV pili-induced slingshotting motion.

Flash animation illustrating A Bacterium Dragging Itself Along a Surface Using Type IV Pili (Twitching Motility).swf by Gary E. Kaiser, Ph.D.
Professor of Microbiology, The Community College of Baltimore County, Catonsville Campus
This work is licensed under a Creative Commons Attribution 4.0 International License.
Based on a work at http://faculty.ccbcmd.edu/~gkaiser/index.html.

Last updated: October, 2018
Please send comments and inquiries to Dr. Gary Kaiser