TABLE 3.

MICs of β-lactam antibiotics for MRSA clinical isolates^a

Isolate	MIC (μg/ml) of:
	Oxacillin		Floxacillin		Cephalothin		Cefoxitin		Cefoperazone
	Control sample	ODN833-treated sample	Control sample	ODN833-treated sample	Control sample	ODN833-treated sample	Control sample	ODN833-treated sample	Control sample	ODN833-treated sample
071001	128	2	1,024	2	512	2	32	2	128	8
071002	>1,024	2	>1,024	2	512	8	512	1	1,024	2
071003	>1,024	2	>1,024	2	512	2	512	1	1,024	4
071004	>1,024	1	>1,024	2	512	8	512	4	1,024	4

^aMICs of β-lactam antibiotics in the presence and absence of anti-mecA PS-ODN833 encapsulated in anionic liposomes for four clinically isolated MRSA strains in broth cultures were determined. The concentration of liposome-encapsulated anti-mecA PS-ODN833 was 18 μM. The classification of S. aureus strains by MICs is as follows. Oxacillin MIC: ≤2 μg/ml, sensitive; ≥4 μg/ml, resistant. Floxacillin MIC: ≤2 μg/ml, sensitive; ≥4 μg/ml, resistant. Cephalothin MIC: ≤8 μg/ml, sensitive; 16 μg/ml, intermediate; ≥32 μg/ml, resistant. Cefoxitin MIC: ≤8 μg/ml, sensitive; 16 μg/ml, intermediate; ≥32 μg/ml, resistant. Cefoperazone MIC: ≤16 μg/ml, sensitive; 32 μg/ml, intermediate; ≥64 μg/ml, resistant.