Figure 1

Extracellular ATP inhibits twitching motility-mediated expansion of P. aeruginosa interstitial biofilms. (A) Representative light microscopy images of P. aeruginosa PAK and PAKpilA interstitial biofilms formed at the interface between a microscope slide coated in solidified nutrient media supplemented with a range of eATP concentrations and a coverslip after incubation at 37°C for 16 h. Scale 50 μm. (B) Surface areas of the interstitial biofilms formed by P. aeruginosa PAK and PAKpilA at the interface between a microscope slide coated in solidified nutrient media supplemented with a range of eATP concentrations and a coverslip after incubation at 37°C for 16 h. Mean ± SD from three independent experiments run in duplicate are presented. (C) Planktonic growth of P. aeruginosa PAK at 37°C over 20 h in media supplemented with 0 mM ATP (black), 2.5 mM ATP (green), 5 mM ATP (yellow), 7.5 mM ATP (magenta), 10 mM ATP (pink), 12.5 mM ATP (orange) or 15 mM ATP (blue). Mean ± SD from three independent experiments each consisting of five technical replicates is presented.