Effect of Artemisia judaica Essential Oil on Bacterial Biofilm and Its Mode of Action

BACKGROUND Drug resistance and failure of antibiotics to treat bacterial infections is the most challenging clinical and public health problem. There is ongoing research for new, safe and effective alternatives to antibiotics for the therapeutic management of bacterial infections. Essential oils are one of the outcomes of such type of research. This study was conducted to evaluate the effect of Artemisia judaica essential oil against the bacterial & the biofilm activity and to study its mode of action. METHODS Minimum biofilm inhibitory concentration (MBIC) susceptibility assays were performed using a biofilm inoculator with a 96-well plate with peg lid. Minimum inhibitory concentration (MIC) was performed in normal microtiter plates using a twofold dilution series. RESULTS The values of the minimum inhibitory concentration (MIC), the minimum bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC) and the minimum biofilm eradication concentration (MBEC) were in the range of 0.25 - 1 mg / mL, 1.0 - 4 mg / mL, 0.50 - 2 mg / mL and 1.0 - 8 mg / mL, respectively. There was increase in the leakage of K. and cellular components through the membrane of the tested bacteria under the effect of essential oil of Artemisia judaica proving that the cell membrane was the site of action of Artemisia judaica. This was shown by its inhibitory effect on the Staphylococcus epidermidis (ATCC 35984) during initial adherence at sub-inhibitory concentrations. CONCLUSIONS The essential oil of Artemisia judaica had the ability to overcome all tested bacterial resistance and also prevents the formation of biofilm. The site of action of Artemisia judaica essential oil was the cell membrane and cell wall.