FIGURE 4.

Suppression of ciprofloxacin-induced mutagenesis by 14. ΔtolC MG1655 E. coli cultures were grown in the presence or absence of 14 (100 μM) and/or a sub-MIC level of ciprofloxacin (1.25 ng/mL). The cultures were plated without selection to determine total population size and on selective rifampin-containing media (100 μg/mL) to quantify the frequency of rifampin-resistance in the population. The mutational frequency was converted to a per-generation mutation rate, with the rate and 95% confidence interval shown. The rate data were calculated based on at least twelve independent cultures under each condition.