TABLE 2.

MICs of norfloxacin, erythromycin, and kanamycin in the presence of increasing concentrations of GSH^a

Strain	Genotype	Norfloxacin MIC (μg/ml) with GSH concn (mM):				Erythromycin MIC (μg/ml) with GSH concn (mM):				Kanamycin MIC (μg/ml) with GSH concn (mM):
		0	5	10	15	0	5	10	15	0	5	10	15
BW25113	WT	0.04	0.16	0.64	1.28	128	512	512	512	1.56	25	50	50
GD100	ΔtolC	0.01	0.02	0.08	−	4	4	4	−	1.56	25	50	−
W4680AE	ΔacrAB ΔacrEF	0.005	0.01	0.02	0.16	4	4	8	32	ND	ND	ND	ND

^a−, no growth; ND, not determined. Strain W4680AE contains a kanamycin resistance cassette.