fa Food Safety and Hygiene Food Safety and Hygiene Short communication <div style="text-align: justify;"><span style="font-size:14px;"><span style="font-family:times new roman;"><strong>Background:</strong> The present study aimed to determine the chemical composition and <em>in-vitro</em> antibacterial activity of <em>Ziziphora clinopodioides</em> essential oil (ZCEO).<span dir="RTL"></span><br> <strong>Methods: </strong>The chemical composition of ZCEO was determined using gas chromatography-mass spectrometry (GC-MS) analysis. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were calculated using the microwell dilution assay to assess the antibacterial effects of ZCEO emulsion and nano-emulsion on <em>E. coli</em> O₁₅₇:H₇.<br> <strong>Results:</strong> A yield of 1% (w/w) was identified for ZCEO isolation and pulegone (58.78%), menthone (1.15%), and isomenthone (9.91%) as the key components of ZCEO phytochemicals. The MIC values of the ZCEO emulsion and nano-emulsion were 0.8 and 0.025 mg/ml, respectively, and the MBC values were estimated at 1.6 and 0.05, respectively.<br> <strong>Conclusion:</strong> It is recommended that the nano-emulsion of ZCEO be applied as a potential source of natural preservatives in food industries.</span></span></div> Essential oil, Antibacterial activity, Nanotechnology, Escherichia coli O157:H7 94 97 http://jhehp.zums.ac.ir/browse.php?a_code=A-10-144-1&slc_lang=fa&sid=1 Saeid Khanzadi Khanzadi@um.ac.ir 10031947532846009720 10031947532846009720 Yes Department of Food Hygiene and Aquatics, School of Veterinary Medicine, Ferdowsi University of Mashhad, Iran. Asghar Azizian dariush.azizian@yahoo.com 10031947532846009721 10031947532846009721 No Department of Food Hygiene and Aquatics, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Iran. Mohammad Hashemi Mo_hashemi@hotmail.com 10031947532846009722 10031947532846009722 No Department of Nutrition, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Mohammad Azizzadeh m-azizzadeh@um.ac.ir 10031947532846009723 10031947532846009723 No Department of Clinical Science, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Iran.