Table 3.

In vitro antimicrobial activity of Erigeron floribundus essential oil.

Species	Strain	Essential Oil		Reference Antibiotic 1
		IZD 2 (mm)	MIC 3 (µg/mL)	IZD (mm)	MIC (µg/mL)
S. aureus	ATCC 29213	14.3 ± 0.6	512	20.67 ± 1.15	0.25
	MRSA 4 -19		1024–2048
	MRSA-42		512–1024
	MRSA-75		512–1024
	MRSA-101		512–1024
E. faecalis	ATCC 29212	8.7 ± 0.6	4096	24.0 ± 2.6	0.5–1
E. coli	ATCC 25922	n.a. 5	N.D. 6	19.7 ± 0.6	0.016
P. aeruginosa	ATCC 27853	n.a.	N.D.	21.7 ± 0.6	0.5
C. albicans	ATCC 24433	9.0 ± 1.0	512	16.33 ± 0.58	4.0

¹ Ciprofloxacin for Gram-positive species, gentamicin for Gram-negative ones; nystatin for C. albicans. ² IZD, inhibition zone diameter. Each value is an average of three independent experiments with standard errors indicated. ³ MIC; minimum inhibitory concentration. ⁴ MRSA, Methicillin-Resistant Staphylococcus aureus. ⁵ n.a., no activity. ⁶ N.D., not determined.