TABLE 4.

Synergistic interactions of natural compounds in combination with antibiotics against RGM strains^a

		Antibiotics
Natural		AMI		CLA		LZD
Compounds	Strain	FICI	Interpretation	FICI	Interpretation	FICI	Interpretation
tCIN	MAB1	0.50	SY	0.63	AD	0.38	SY
	MAB4	0.38	SY	0.75	AD	0.52	AD
	MAB5	0.38	AD	0.28	SY	0.50	SY
	MC4	0.53	AD	0.28	SY	0.38	SY
	MC6	1.00	AD	1.00	AD	0.53	AD
	MC7	0.75	AD	0.75	AD	0.63	AD
	MF1	0.38	SY	0.63	AD	1.25	IN
	MF3	0.25	SY	0.25	SY	2.03	IN
	MF6	0.38	SY	0.38	SY	2.06	IN
	ATCC14468	0.53	AD	0.27	SY	0.25	SY
CAR	MAB1	2.06	AD	0.38	SY	0.19	SY
	MAB4	0.38	SY	0.75	AD	0.53	AD
	MAB5	0.38	SY	0.50	SY	0.27	SY
	MC4	0.75	AD	0.63	AD	0.50	SY
	MC6	1.00	AD	0.63	AD	0.38	SY
	MC7	0.75	AD	0.75	AD	0.56	AD
	MF1	0.50	SY	4.01	IN	1.00	AD
	MF3	0.28	SY	1.02	AD	0.19	SY
	MF6	0.50	SY	1.50	IN	0.50	SY
	ATCC14468	0.50	SY	0.31	SY	0.25	SY
GEN	MAB1	1.03	AD	0.38	SY	1.25	IN
	MAB4	0.53	AD	0.53	AD	1.25	IN
	MAB5	1.03	AD	0.38	SY	1.25	IN
	MC4	0.63	AD	0.31	SY	1.03	AD
	MC6	0.56	AD	0.53	AD	0.38	SY
	MC7	0.56	AD	0.56	AD	0.56	AD
	MF1	0.56	AD	0.52	AD	1.03	AD
	MF3	0.53	AD	0.38	SY	0.75	AD
	MF6	0.53	AD	0.50	SY	0.75	AD
	ATCC14468	0.75	AD	0.27	SY	0.75	AD
PHL	MAB1	1.02	AD	0.63	AD	1.00	AD
	MAB4	1.02	AD	0.52	AD	1.00	AD
	MAB5	1.02	AD	0.38	SY	1.00	AD
	MC4	1.02	AD	0.56	AD	0.75	AD
	MC6	1.03	AD	2.03	IN	0.38	SY
	MC7	1.13	IN	0.53	AD	0.50	SY
	MF1	0.52	AD	0.51	AD	1.00	AD
	MF3	0.52	AD	0.56	AD	1.00	AD
	MF6	0.52	AD	0.56	AD	0.63	AD
	ATCC14468	1.25	IN	0.75	AD	1.50	IN
CIT	MAB1	0.50	SY	0.31	SY	0.63	AD
	MAB4	0.50	SY	0.38	SY	0.50	SY
	MAB5	0.38	SY	0.25	SY	0.38	SY
	MC4	0.57	AD	0.53	AD	1.27	IN
	MC6	0.38	SY	0.50	SY	1.00	AD
	MC7	0.19	SY	0.25	SY	0.32	SY
	MF1	0.08	SY	0.56	AD	0.50	SY
	MF3	0.28	SY	0.38	SY	0.33	SY
	MF6	0.13	SY	0.25	SY	0.38	SY
	ATCC14468	0.16	SY	0.38	SY	0.75	AD
GER	MAB1	0.50	SY	0.13	SY	0.19	SY
	MAB4	0.19	SY	0.19	SY	0.19	SY
	MAB5	0.25	SY	0.31	SY	0.25	SY
	MC4	0.39	SY	1.02	IN	0.63	AD
	MC6	0.56	AD	2.00	IN	1.13	IN
	MC7	0.19	SY	0.16	SY	0.19	SY
	MF1	0.19	SY	0.25	SY	0.75	AD
	MF3	0.19	SY	0.13	SY	0.13	SY
	MF6	0.13	SY	0.16	SY	0.16	SY
	ATCC14468	0.13	SY	0.09	SY	0.63	AD

^a Determined using the checkerboard assays. Fractional inhibitory concentration Indexes (FICIs) were interpreted as synergistic (SY) when it was ≦0.5, as additive (AD) when it was >0.5–1, indifferent (IN) when it was >1–4.0, and antagonistic (AN) when it was >4 (Phytomedicine. 2015). tCIN, trans-Cinnamaldehyde; CAR, carvacrol; GEN, gentisaldehyde; PHL, phloroglucinaldehyde; CIT, citral; GER, geraniol; AMI, amikacin; CLA, clarithromycin; LZD, linezolid.