Table 4.

Fractional Inhibitory Concentration Index (FICI) of the EO–HY pairs against L. monocytogenes strains and their type of interaction.

Combination EO/HY	Strain	FIC		FICI	Outcome
		EO	HY
CEO/CHY	ATCC 19114	0.500	1.000	1.500	Indifferent
	LM6	0.500	0.250	0.750	Additive
	LM13	0.500	0.250	0.750	Additive
	L315	0.500	0.500	1.000	Additive
	L3	0.500	0.500	1.000	Additive
OEO/OHY	ATCC 19114	0.500	0.250	0.750	Additive
	LM6	0.500	0.500	1.000	Additive
	LM13	0.500	0.250	0.750	Additive
	L315	0.500	0.062	0.562	Additive
	L3	0.500	0.500	1.000	Additive
CEO/OHY	ATCC 19114	0.250	0.500	0.750	Additive
	LM6	0.500	0.250	0.750	Additive
	LM13	0.500	0.125	0.625	Additive
	L315	0.500	0.500	1.000	Additive
	L3	0.500	0.500	1.000	Additive
OEO/CHY	ATCC 19114	0.500	0.500	1.000	Additive
	LM6	0.500	0.500	1.000	Additive
	LM13	0.500	0.250	0.750	Additive
	L315	0.500	0.007	0.507	Synergistic
	L3	0.500	0.250	0.750	Additive

Type of interaction: synergistic if FICI ≤ 0.5, additive if 0.5 < FICI ≤ 1, indifferent if 1 < FICI ≤ 4, and antagonistic if FICI > 4.