FIG. 3.

Flagella are necessary for biofilm formation on cholesterol-coated surfaces, whereas motility is dispensable. Serovar Typhimurium strains were grown with and without 3% crude ox bile extract and added to cholesterol-coated Eppendorf tubes. Biofilms were stained with crystal violet and extracted with acetic acid, and the absorbance at 570 nm was measured. *, statistically significantly different (P < 0.005) based on a two-tailed Student t test. OD570, optical density at 570 nm.