Table 7.

Antimicrobial activities against S. aureus efflux strains

	Comp.	SCA#	WT 8325-4	NorA− K1758	NorA++ K2361	MepA− K2908	MepA++ K2068
Bacteriostatic effect, MIC (μM)	1*	SCA21	8	8	8	8	6
	7b	SCA107	2.1	3.1	3.1	2.1	3.1
	12a	SCA112	1.6	1.6	1.8	1.0	1.3
Bactericidal effect, log # of cell reduced	1	SCA21	3	3	4	2	3

Deletion (NorA⁻, MepA⁻) and over-expression (NorA⁺⁺, MepA⁺⁺) of NorA and MepA efflux pump strains, K1758, K2361, K2908, and K2068 are derivatives from S. aureus 8325-4. Bactericidal effects were determined by counting CFU after 1 hr treatment at 37°C with 25 μM.

^*the initial MIC tested for Compound 1 was from tube assay.