Synergistic Effect between Cryptotanshinone and Antibiotics against Clinic Methicillin and Vancomycin-Resistant Staphylococcus aureus

Table 2

Synergistic effects of the cryptotanshinone with oxacillin in isolated MRSA, VRSA, MSSA, and some of reference bacteria.

Samples	Agent	MIC/MBC (μg/mL)		FIC/FBC	FICI/FBCI^2	Outcome
		Alone	Combination^1
MSSA ATCC 25923^3	Cryptotanshinone	64/256	8/32	0.125/0.125	0.375/0.375	Synergistic/synergistic
	Oxacillin	0.25/1	0.0625/0.25	0.25/0.25
MRSA ATCC 33591^4	Cryptotanshinone	4/16	1/4	0.25/0.25	0.5/0.5	Synergistic/synergistic
	Oxacillin	8/16	2/4	0.25/0.25
VRSA 3A063^5	Cryptotanshinone	2/4	0.5/2	0.25/0.5	0.375/0.375	Synergistic/synergistic
	Oxacillin	512/1024	64/128	0.125/0.125
VRSA 3A066^6	Cryptotanshinone	4/16	1/4	0.25/0.25	0.375/0.5	Synergistic/synergistic
	Oxacillin	512/1024	64/256	0.125/0.25
MSSA 1^7	Cryptotanshinone	16/64	2/8	0.125/0.125	0.375/0.25	Synergistic/synergistic
	Oxacillin	0.5/1	0.125/0.125	0.25/0.125
MSSA 2	Cryptotanshinone	32/128	16/32	0.5/0.25	0.375/0.375	Synergistic/synergistic
	Oxacillin	1/2	0.125/0.25	0.125/0.125
MRSA 1^8	Cryptotanshinone	16/32	4/16	0.25/0.5	0.5/0.75	Synergistic/additive
	Oxacillin	128/256	32/64	0.25/0.25
MRSA 2	Cryptotanshinone	64/128	16/16	0.25/0.125	0.5/0.375	Synergistic/synergistic
	Oxacillin	8/32	2/8	0.25/0.25
MRSA 3	Cryptotanshinone	4/16	0.5/4	0.125/0.25	0.375/0.375	Synergistic/synergistic
	Oxacillin	128/512	32/64	0.25/0.125
MRSA 4	Cryptotanshinone	4/8	2/2	0.5/0.25	0.75/0.375	Additive/synergistic
	Oxacillin	512/2048	128/256	0.25/0.125
MRSA 5	Cryptotanshinone	64/128	16/32	0.25/0.25	0.375/0.5	Synergistic/synergistic
	Oxacillin	512/1024	64/256	0.125/0.25
MRSA 6	Cryptotanshinone	4/16	1/4	0.25/0.25	0.5/0.5	Synergistic/synergistic
	Oxacillin	64/256	16/64	0.25/0.25
MRSA 7	Cryptotanshinone	8/16	2/8	0.25/0.5	0.375/0.75	Synergistic/additive
	Oxacillin	512/1024	64/256	0.125/0.25
MRSA 8	Cryptotanshinone	32/64	8/32	0.25/0.5	0.5/0.625	Synergistic/synergistic
	Oxacillin	512/2048	128/256	0.25/0.125
MRSA 9	Cryptotanshinone	8/16	2/4	0.25/0.25	0.375/0.3125	Synergistic/synergistic
	Oxacillin	512/1024	64/64	0.125/0.0625
MRSA 10	Cryptotanshinone	16/64	2/8	0.125/0.125	0.3125/0.25	Synergistic/synergistic
	Oxacillin	512/1024	32/128	0.0625/0.125
MRSA 11	Cryptotanshinone	8/32	1/4	0.125/0.125	0.375/0.375	Synergistic/synergistic
	Oxacillin	64/128	16/64	0.25/0.5
MRSA 12	Cryptotanshinone	4/8	1/2	0.25/0.25	0.5/0.5	Synergistic/synergistic
	Oxacillin	128/256	32/64	0.25/0.25
MRSA 13	Cryptotanshinone	32/128	8/32	0.25/0.25	0.5/0.375	Synergistic/synergistic
	Oxacillin	32/128	8/8	0.25/0.125
MRSA 14	Cryptotanshinone	8/16	2/4	0.25/0.25	0.375/0.5	Synergistic/synergistic
	Oxacillin	8/16	1/4	0.125/0.25
MRSA 15	Cryptotanshinone	4/16	1/8	0.25/0.5	0.5/0.75	Synergistic/additive
	Oxacillin	128/256	32/64	0.25/0.25
MRSA 16	Cryptotanshinone	8/16	2/4	0.25/0.25	0.75/0.375	Additive/synergistic
	Oxacillin	128/512	64/64	0.5/0.125

 ¹The MIC and MBC of cryptotanshinone with oxacillin.
²The FIC index.
³MSSA (ATCC 25923): reference strain methicillin-sensitive Staphylococcus aureus.
⁴MRSA (ATCC 33591): reference strain methicillin-resistant Staphylococcus aureus.
⁵VRSA 3A063: vancomycin-resistant Staphylococcus aureus isolated clinically.
⁶VRSA 3A066: vancomycin-resistant Staphylococcus aureus isolated clinically.
⁷MSSA (1-2): methicillin-sensitive Staphylococcus aureus isolated clinically.
⁸MRSA (1–16): methicillin-resistant Staphylococcus aureus isolated clinically.