Synergistic Effect and Antiquorum Sensing Activity of Nymphaea tetragona (Water Lily) Extract

Table 3

Fractional inhibitory concentration (FIC) and FIC index (FICI) of combination between tylosin and EFNTE.

Tylosin		EFNTE		FICI	Interpretation
Con^c (𝜇g/mL)	FIC of drug A	Con^c (𝜇g/mL)	FIC of drug B	(FIC of A + FIC of B)
1024	MIC of A	0	MIC of A	MIC of A	MIC of A
1024	1	6	0.0077	1.008	IND
1024	1	12	0.0154	1.015	IND
1024	1	24	0.0307	1.031	IND
512	0.5	49	0.063	0.563	ADI
256	0.25	98	0.125	0.375	SYN
256	0.25	195	0.25	0.499	SYN
128	0.125	391	0.5	0.626	ADI
64	0.0625	391	0.5	0.563	ADI
0	MIC of B	781	MIC of B	MIC of B	MIC of B

EFNTE: ethyl acetate fraction of N. tetragona 50% methanol extract; Con^c: concentration; drug A: tylosin; drug B: EFNTE; SYN: synergistic effect; ADI: additive effect; IND: indifferent effect; MIC: minimum inhibitory concentration. The FICI was interpreted as follows: synergistic effect (0 < FICI ≤ 0.5), additive effect (0.5 < FICI ≤ 1), and indifferent effect (1 < FICI ≤ 4).