The Effect ofAqueousExtract and Essential Oils of the Leaves of Eucalyptus incrassate on β- Lactam ResistantStaphylococcusaureus

Abstract

According to theextraction procedure,Eucalyptus incrassata leave sampleyielded 5% and 2% w/w(Based on dry leaves ) ofthe aqueousextract and essential oils respectively.Disk diffusion method was usedto determine the antimicrobial activity of aqueous extract and essential oils ofE .incrassata leaves against eight isolates of multidrug- resistant ofStaphylococcus aureus (S. aureus).It was found that aqueous extract and essential oils have variable antimicrobial activity(the inhibition zone diameter ranged from 7 to 14 mm respectively ) , while essential oils showed more effect than aqueous extract .It was noticed that values of Minimal Inhibitory Concentration ( MIC ) for aqueous extract is different from MIC of essential oils and these values were ranged from12.5 to 75mg/ml.It was also found that isolates collected from wound infections showed high resistance against aqueous extract and essential oils with MIC ranged from 50-75mg/ml, these variation in the MIC are probably due to some virulence factors which have a unique genetic determinant .The results indicated that the potential usefulness of the aqueous extract and essential oilsof Eucalyptus incrassataas an antimicrobial agent can be used in the treatment of multidrug-resistant S. aureusinfectious .