TABLE 1.

Changes in MICs in relationship to Mcc24 resistance

Treatment	Strain	MIC (μg/ml) ofa:				Zone of inhibition around MC4100pGOB18 disk
		CIP	TET	CHL	RIF
Exposure to disk soaked in MC4100pGOB18	SL1344	0.125	4	2	12.5	Yes
Exposure to TCA-precipitated supernatants from MC4100pGOB18	SL1344	NDb	ND	ND	ND	Yes
Exposure to pronase-treated TCA-precipitated supernatants from MC4100pGOB18	SL1344	ND	ND	ND	ND	No
3.5 mM salicylate	SL1344	4	16	32	50	No
Exposure to disk soaked in MC4100pGOB18	SL1344/mtfI-pCRXL	ND	ND	ND	ND	No
None	8431	4	32	64	50	ND
Exposure to disk soaked in MC4100pGOB18	8431	4	32	64	50	No
None	SL1344/CFP/marR	0.125	4	2	12.5	ND
Exposure to disk soaked in MC4100pGOB18	SL1344/CFP/marR	0.125	4	2	12.5	Yes
Exposure to disk soaked in MC4100pGOB18 in the presence of 3.5 mM salicylate	SL1344/CFP/marR	4	16	32	50	No
Exposure to disk soaked in MC4100pGOB18 in the presence of 3.5 mM salicylate plus 0.2% arabinose	SL1344/CFP/marR	0.5	8	8	12.5	Yes
Exposure to disk soaked in MC4100pGOB18 in the presence of 3.5 mM salicylate plus two exposures to 0.2% arabinose	SL1344/CFP/marR	0.25	4	4	12.5	Yes

^aConcentrations of antibiotics were as follows: 8, 4, 2, 1, 0.5, 0.25, and 0.125 μg/ml for ciprofloxacin (CIP); 64, 32, 16, 8, 4, 2, and 1 μg/ml for tetracycline (TET) and for chloramphenicol (CHL); and 100, 50, 25, 12.5, 6.3, 3.2, and 1.6 μg/ml for rifampin (RIF). 

^bND, not determined.