Table 1.

MICs, FIC, and FIC index of amoxicillin, penicillin, quercetin, kaempferol against S. epidermidis

Strains	MIC (μg/mL)					FIC (μg/mL) = FIC index
	Amx	Pen	Nis	Que	Kae	Amx + Que	Pen + Kae
S. epidermidis DMST 5038	16R	200R	256	256	>1024	4 + 64 = 0.5SI	64 + 64 = < 0.38SI
S. epidermidis DMST 5023	16R	200R	256	256	> 1024	4 + 64 = 0.5SI	64 + 64 = < 0.38SI
S. epidermidis DMST 5868	16R	200R	256	384	> 1024	4 + 96 = 0.5SI	64 + 64 = < 0.38SI
S. epidermidis DMST 4248	16R	200R	256	384	> 1024	4 + 96 = 0.5SI	64 + 64 = < 0.38SI
S. aureus ATCC 29213a	0.5S	0.5S	1	N/D	N/D	N/D	N/D

Each compound was measured three times

MIC Minimum inhibitory concentrations, FIC Fractional inhibitory concentration, Amx amoxicillin, Pen penicillin, Nis nisin, Que quercetin, Kae kaempferol

^S = Susceptible; ^R = resistant; ^SI = Synergistic interaction; N/D not determined

^a S. aureus ATCC 29213 was used as a positive control