FIG. 9.

Influence of exogenous C4-HSL on twitching motility. P. aeruginosa K1120, H2590 (RhlI⁻), and K2784 (RhlR⁻) were inoculated onto Fe-limited (− Fe) or Fe-replete (100 μM FeCl₃) (+ Fe) glucose minimal agar without (− HSL) or supplemented with (+ HSL) 5 μM C4-HSL. Following incubation at 37°C for 40 h, the twitching zones were stained and their diameters measured. Results shown represent the means ± standard deviations for a representative assay (16 individual twitching zones measured per strain and/or growth condition on two separate plates) performed in duplicate.