TABLE 3.

Minimal inhibition concentrations (MICs) of the tested antimicrobial drugs.

Drug	Minimum inhibitory concentrations (μg/ml)
	E.coli/pET28a	E.coli/pET28a-ybhF	E.coli△ybhF	E.coli△ybhS	E.coli△ybhR	E.coli △acrB	E.coli△acrB△ybhF
Tetracycline	1	2	0.5	1	0.5	0.25	0.125
Oxytetracycline	32	128	16	32	16	8	4
Chlortetracycline	64	64	1	64	1	0.125	< 0.125
Doxycycline	32	32	1	32	1	0.125	< 0.125
Ethidium	256	256	128	256	128	128	16
Hoechst	128	128	64	128	64	64	32
Cefoperazone	1	1	1	1	1	0.125	0.125
Cefazolin	64	64	32	64	64	32	32
Streptomycin	> 256	>256	> 256	>256	> 256	>256	> 256
Ampicillin	8	8	8	8	8	4	4
Roxithromycin	> 256	>256	> 256	>256	> 256	>256	> 256
Chloramphenicol	32	32	32	32	32	0.5	0.5
Rifampicin	16	16	16	16	16	8	8
Norfloxacin	2	2	2	2	2	< 0.125	<0.125
Deoxycholate	> 256	>256	> 256	>256	> 256	>256	> 256
Sodium cholate	> 256	>256	> 256	>256	> 256	>256	> 256
Ofloxacin	0.125	0.125	0.125	0.125	0.125	< 0.125	<0.125
Doxorubicin	4	4	4	4	4	4	1
Daunorubicin	64	64	64	64	64	1	1
Acridine flavin	0.5	0.5	0.5	0.5	0.5	0.5	0.5
Quinine	> 256	>256	> 256	>256	> 256	0.5	0.5