Fig. 2.

Mutations that decrease FimH SP function reduce fimbrial number and increase fimbrial length. (A) FimH SP transport activity measured by units of alkaline phosphatase activity. (B) Surface FimH measured by flow cytometry. (C and D) Average (C) number and (D) length of type 1 fimbriae measured on electron micrographs. (E and F) Uncoiled fimbrial length (E) and percent of fimbriae >20 μm (F) remaining attached to the AFM cantilever at the end of a pull. All error bars represent SEM. Double horizontal lines represent WT ± SEM. *, P < 0.05; **, P < 0.01; ***, P < 0.001