Inhibition of Some Multidrug-Resistant Bacteria Using Prepared Essential Oil Nanoemulsion Formulas and Their Mode of Action.

Objective: The use of essential oils for the preparation of different nanoemulsions (NEa, NEb and NEc) and detect their biological activities. Methods: Nanoemulsiona were prepared by mixing the essential oil (10%) of Coriandrum seed of Coriandrum sativum, Ginger roots of Zingiber officinale, or Achillea leaves of Achillea clavennae), sterile water, and surfactants (Brij 30, Span 20, Triton X-100, Tween 60) in addition to the 0.1M Tris-HCl buffer (pH 7.22). The three prepared nanoemulsions were examined and characterized. Their antibacterial activities were examined against some multidrug-resistant Gram-positive and negative bacteria. Results: The maximum activity was recorded by NEb against Serratia marcescens, Staphylococcus aurous, Micrococcus luteus, Enterococcus faecalis, Streptococcus pyogenes, and Staphylococcus saprophyticus while lower activity was obtained against Klebsiella pneumonia and Escherichia coli. The minimum inhibitory concentrations (MICs) of the NEb ranged from 40--60 µl/ml of the nutrient broth. NEb affects the cell counts and morphology of S. marcescens and destroys the bacterial cells by reducing cell respiration and enhancing the cell permeability and leakage of protein, DNA, and potassium of the bacterial cell membrane. NEb recorded no toxicity against Artimia salina and HaCaT cell line. It decreases biofilm formation by 51%, bacterial infection, and cell attachment. Conclusion: This study suggests that NEs have great antibacterial activity against some human pathogens and process different modes of action, thus they can be used effectively to treat different bacterial infections. [ABSTRACT FROM AUTHOR]