Antibacterial Activity of Salvadora persica L. (Miswak) Extracts against Multidrug Resistant Bacterial Clinical Isolates

Table 2

The MIC values of aqueous and methanol extracts of miswak against 10 MDR pathogenic organisms.

MDR bacterial; isolates	MIC values (mg/mL)		MIC values (µg/mL)
	Miswak extracts		Positive control
	Aqueous	Methanol	VAN	TOB
MRSA	12.5	6.25	1.0	NT
MRSE	6.25	3.125	0.5	NT
Streptococcus pyogenes	1.56	1.56	0.125	NT
E. faecalis	3.125	3.125	0.5	NT
E. coli	1.56	0.39	NT	0.25
K. pneumonia	3.125	0.781	NT	0.5
P. aeruginosa	6.25	1.56	NT	1.0
S. marcescens	1.56	1.56	NT	2.0
A. baumannii	12.5	6.25	NT	8.0
S. maltophilia	12.5	6.25	NT	4.0

MRSA: methicillin-resistant staphylococcus aureus, MRSE: methicillin-resistant staphylococcus epidermidis.
VAN: vancomycin, TOB: tobramycin, and NT: not tested.
The CLSI MIC Interpretive Criteria for vancomycin (VAN): ≤2 µg/mL: Susceptible, 4–8 µg/mL: Intermediate, ≥16 µg/mL: Resistant [21].
The CLSI MIC interpretive criteria for tobramycin (TOB): ≤4 ug/mL: susceptible, 8 µg/mL: intermediate, and ≥16 µg/mL: resistant [21].