en تخصصي Special Original article Original article <p style="text-align: justify;"><span style="font-family:times new roman;"><strong>Background:</strong> <em>Escherichia coli</em> O157:H7 is a Gram-negative and facultative anaerobic food-borne bacterial pathogen. The major purpose of this study was to evaluate physicochemical characteristics of nanoliposome garlic Essential Oil (EO) and its antibacterial effect on <em>E. coli</em> O157:H7.<br> <strong>Methods:</strong> Nanoliposome garlic EO was prepared by ethanol injection method and its physicochemical properties were evaluated. After inoculation of <em>E. coli</em> O157:H7 to experimental groups, minimum inhibitory concentration and minimum bactericidal concentration were assessed. Data were analyzed using SPSS software (version 16.0).<br> <strong>Results:</strong> The average particle sizes of prepared nanoliposomes were 131.73&plusmn;14.31 nm with a polydispersity index of 0.212&plusmn;0.013. The percentage of liposome permeability after 5, 10, 30, and 50 days were 0.46%, 2.47%, 5.63%, as well as 7.29%, respectively, revealing significant difference (<em>p</em><0.05) among various intervals. Also, the minimum inhibitory concentration as well as minimum bactericidal concentration values of the nanoliposome encapsulated garlic EO against <em>E. coli</em> O157:H7 were 0.02% and 0.03%, respectively, and for non-encapsulated EO were 0.03% and 0.04%, respectively.<br> <strong>Conclusion:</strong> Nanoliposome encapsulated garlic EO showed enhancing antimicrobial activity against <em>E. coli</em> O157:H7 in comparison with the non-encapsulated one.</span><br> <br> &nbsp;</p> Garlic, Anti-Bacterial Agents, Nanotechnology 24 28 http://jfqhc.ssu.ac.ir/browse.php?a_code=A-10-1-142&slc_lang=en&sid=1 A. Zabihi No Department of Food Hygiene, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran A. Akhondzadeh Basti Yes Department of Food Hygiene, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran G. Amoabediny No Department of Chemical Engineering, Faculty of Engineering, University of Tehran, Tehran, Iran A. Khanjari No Department of Food Hygiene, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran J. Tavakkoly Bazzaz No Department of Medical Genetics, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran F. Mohammadkhan No Department of Food Hygiene, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran A. Hajjar Bargh No Department of Food Sciences and Technology, Faculty of Food Sciences, Islamic Azad University, Science and Research Branch, Tehran, Iran E. Vanaki No Department of Food Hygiene, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran