FIG. 3.

(A) AFM image of the pole region of a P. aeruginosa PAO1 bacterium showing a flagellum and several straight pili. (B) Pili embedded in the layer of surface deposit. In some regions (black arrow), pili appear to be nearly submerged in a smooth region of the deposit. The white arrow points to a pili bundle. (C) Example of a bare region of the mica substrate traversed by pili fibers. (D) Cross section of the pilus in panel C along the line indicated. Such cross sections had pili diameters of 4 to 6 nm. Scale bars, 250 nm.