FIG 1.

Role of OsaR in the bacterial tolerance to carbenicillin. Bacteria were treated with carbenicillin at an OD₆₀₀ of 0.4 in LB medium at 37°C. Bacteria were collected at the indicated time points, and the CFU were determined by serial dilution (1:10) and plating. Images on the right show the growth state of PAK and ΔosaR strains in tubes after exposure to carbenicillin (320 μg ml⁻¹) for 24 h; the treated cultures were then dropped on LB plates by serial dilution (1:10). All data were obtained from three independent experiments with at least three replicates. Error bars represent standard deviations (SDs). **, P < 0.01 by Student's t test.