Table 1. Synergy of 600 Da BPEI and β-Lactams against MRSA 700787 and MSSA 25923^a.

		MICA (μg/mL)/μM		MICB (μg/mL)/μM
strain	antibiotic	alone	comb.	alone	comb.	FICI	outcome
MRSA 700787	oxacillin	64/149	4/9	4/6.6	0.5/0.8	0.188	synergy
			0.5/1.1		1/1.6	0.258
	ampicillin	128/345	8/22	4/6.6	0.5/0.8	0.188	synergy
			2/5		1/1.6	0.266
	amoxicillin	128/305	8/22	4/6.6	1/1.6	0.313	synergy
	methicillin	64/160	4/10	4/6.6	2/3.3	0.563	additivity
	meropenem	2/4.6	0.5/1.1	4/6.6	0.5/0.8	0.375	synergy
	chloramphenicol	8/25	2/6	4/6.6	1/1.6	0.500	additivity
	linezolid	2/5.9	0.5/1.5	4/6.6	1/1.6	0.500	additivity
	vancomycin	2/1.3	2/1.3	4/6.6	4/6.7	1.0	no synergy
MSSA 25923	oxacillin	0.064/0.14	0.032/0.072	32/53	8/13	0.75	additivity
	ampicillin	0.064/0.17	0.032/0.086	32/53	8/13	0.75	additivity
	amoxicillin	0.064/0.16	0.016/0.038	32/53	16/27	0.75	additivity

^aMIC_A is minimum inhibitory concentration of the antibiotic; MIC_B is minimum inhibitory concentration of BPEI; FICI is fractional inhibitory concentration index.