FIG 2.

Nitrate decreases the levels of second messenger c-di-GMP in Salmonella. (A) Images of wild-type S. Typhimurium transformed with pMMB-Gm-Bc3-5AAV plasmid were grown overnight under biofilm-inducing conditions then were treated with NaNO₃ for 1 to 4 h. Bacteria were imaged using a TC5 confocal microscope at 100× oil magnification. (B) The percentage of c-di-GMP-positive cells determined as the number of TurboRFP-positive cells divided by the number of Amcyan-positive cells for each individual field × 100. ****, P < 0.0001; ***, P = 0.0003.