Mutagenesis induced by 12 quinolone antibacterial agents in Escherichia coli WP2uvrA/pKM101

The mutagenic potential of 12 quinolone antibacterial agents (quinolones) was examined at concentrations of 3.91–1000 ng/plate with or without S9 mix in Escherichia coli WP2uvrA/pKM101. All quinolones showed mutagenic potential in the strain: the maximum numbers of revertant colonies were observed at 7.81 ng/plate for clinafloxacin and sitafloxacin; 15.63 ng/plate for ciprofloxacin, gatifloxacin, grepafloxacin, levofloxacin, moxifloxacin, and trovafloxacin; and 31.25–500 ng/plate for enoxacin, lomefloxacin, norfloxacin and ofloxacin. The numbers for all quinolones were comparable between the groups with and without S9 mix. In all quinolones, bactericidal effects were observed at one or two higher concentrations than their mutagenic concentrations except for enoxacin without S9 mix. From these results, the WP2uvrA/pKM101 strain is proved to be highly sensitive to quinolones.