Modulation of Drug Resistance in Staphylococcus aureus with Coumarin Derivatives

Table 1

MIC values (μg/mL) of antibiotics in the absence and presence of coumarin derivatives against S. aureus strains: SA-1199B (NorA), RN4220 (MsrA), and IS-58 (TetK).

Antibiotic + coumarin	MIC (μg/mL)
	IS-58 (TetK); Tetracycline	RN4220 (MrsA); Erythromycin	SA-1199B (NorA); Norfloxacin
Antibiotics alone	64	>256	128
Antibiotics + 1	64	>256	64 (2x)
Antibiotics + 11	64	>256	32 (4x)
Antibiotics + 13	64	>256	32 (4x)
Antibiotics + 16	64	>256	16 (8x)
Antibiotics + 17	32 (2x)	>256	64 (2x)
Antibiotics + 18	32 (2x)	>256	64 (2x)
Antibiotics + 19	64	>256	64 (2x)