FIG 1.

The impact of recA gene inactivation and detoxification system suppression on cell growth in the presence of sublethal quinolone concentrations. OD values for E. coli BW25113 and all genetic combinations with ciprofloxacin concentrations of 0.001 mg/liter at 20 h. Data are represented as the mean of at least four independent measurements. The OD of all constructions was similar in the nonantibiotic control (data not shown). Standard deviations are indicated by error bars. Significant P values are noted (***, P < 0.001).