Table 1.

Changes in MICs in relationship to Mcc24 resistance

TreatmentStrainMIC (μg/ml) ofa:Zone of inhibition around MC4100pGOB18 disk
CIPTETCHLRIF
Exposure to disk soaked in MC4100pGOB18SL13440.1254212.5Yes
Exposure to TCA-precipitated supernatants from MC4100pGOB18SL1344NDbNDNDNDYes
Exposure to pronase-treated TCA-precipitated supernatants from MC4100pGOB18SL1344NDNDNDNDNo
3.5 mM salicylateSL13444163250No
Exposure to disk soaked in MC4100pGOB18SL1344/mtfI-pCRXLNDNDNDNDNo
None84314326450ND
Exposure to disk soaked in MC4100pGOB1884314326450No
NoneSL1344/CFP/marR0.1254212.5ND
Exposure to disk soaked in MC4100pGOB18SL1344/CFP/marR0.1254212.5Yes
Exposure to disk soaked in MC4100pGOB18 in the presence of 3.5 mM salicylateSL1344/CFP/marR4163250No
Exposure to disk soaked in MC4100pGOB18 in the presence of 3.5 mM salicylate plus 0.2% arabinoseSL1344/CFP/marR0.58812.5Yes
Exposure to disk soaked in MC4100pGOB18 in the presence of 3.5 mM salicylate plus two exposures to 0.2% arabinoseSL1344/CFP/marR0.254412.5Yes
  • a Concentrations 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).

  • b ND, not determined.