Background: The tendency to replace synthetic drugs with plants products has been increased in recent decades. In- crease in Bacterial antibiotic resistance to antibiotics is a ma- jor public health challenges. Plant matter can be a good op- tion in the management and treatment of bacterial antibiotic resisatance. The aim of this study was to investigate the anti- bacterial activity of the alcoholic extract of Eucalyptus micro- theca.

Methods: 10 gr dried powder of E. microtheca leaf were mixed in 100 cc of %96 ethanol stayed in refrigerator over- night; then was pure with purification paper and extractions were obtained after alcohol evaporation. Preparation of methanolic extract was done due to the same method. Dif- ferent concentrations of this methanolic and ethanolic ex- tracts from 0.05 to 0.4 g/ml were tested by disc diffusion method against Staphylococcus aureus ATCC: 25923, Bacillus subtilis ATCC: 6633, Escherichia coli ATCC: 25922 and Pseudo- monas aeruginosa ATCC: 2785.

Results: The results showed that the most antibacterial ef- fects of both ethanolic and methanolic extractions was against S. …