Antimicrobial effect of Satureja bachtiarica extracts aqueous and ethanolic on Escherichia coli and Staphylococcus aureus

In this study antimicrobial effect of extracts evaluated by two methods, “Collins method” and “disk agar diffusion method” on Escherichia coli PTCC 1330 and Staphylococcus aureus PTCC 1337 microorganisms. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) for both species determined by using a dilution method. All ethanolic extract concentrations had inhibitory effect in the disk agar diffusion method. In “Collins method” ethanolic extract in 2000 µg/ml concentration, could prevent the growth of both strains on medium. The aqueous extract, had no antimicrobial significant effect in 2000 µg/ml concentration. The ethanolic extract MIC of Satureja bachtiarica for Staphylococcus aureus was 8 mg/ml, and for Escherichia coli was 16 mg/ml. But the aqueous extracts MIC of Satureja bachtiarica for Staphylococcus aureus was 32 mg/ml and for Escherichia coli was 64 mg/ml. The ethanolic extract MBC of Satureja bachtiarica for Staphylococcus aureus was 16 mg/ml, and for Escherichia coli was 32 mg/ml. But the aqueous extracts MBC of Satureja bachtiarica for Staphylococcus aureus was 64 mg/ml and for Escherichia coli was 256 mg/ml. The results indicate that ethanolic extract of Satureja bachtiarica have the greatest effect on gram positive bacterium Staphylococcus aureus PTCC 1337.