en Food Safety and Hygiene Food Safety and Hygiene پژوهشي Original Article <div style="text-align: justify;"><span style="font-size:14px;"><span style="font-family:times new roman;"><strong>Background:</strong> The purpose of this study was to determine the effect of rosemary essential oil (REO) nanoemulsion against some important food borne pathogens.<span dir="RTL"></span><br> <strong>Methods: </strong>Antibacterial effects of REO and REO nanoemulsion were determined using Agar disc diffusion, Broth microdilution and Steam phase diffusion methods against <em>Staphylococcus aureus</em>, <em>Escherichia coli</em>, <em>Pseudomonas</em> <em>aeruginosa</em>, <em>Shewanella SP</em>, <em>Listeria monocytogenes</em> and <em>Salmonella enteritidis</em>.<br> <strong>Results:</strong> Antibacterial effect of REO and REO nanoemulsion was increased with concentration enhancing of REO. There was no significant antibacterial activity in the effectiveness of nanoemulsion on the studied bacteria in comparison with REO in both disk diffusion and steam phase diffusion methods. MIC and MBC analysis of REO and prepared REO nanoemulsion showed that REO and its nanoemulsion have inhibited all studied bacteria. REO showed better inhibitory effects. REO and nanoemulsion of rosemary essential oil have the greatest effect on <em>Shewanella SP</em>., <em>L. monocytogenes</em>, <em>S. aureus</em>, <em>S.enteritidis</em>, <em>E. coli </em>and <em>P. aeruginosa</em>, respectively.<span dir="RTL"></span><br> <strong>Conclusion:</strong> In total, it can be said that REO and its nanoemulsion are desirable to inhibit the growth of food borne pathogens and can be a good choice as antimicrobial agents in food industry to enhance safety and extend foods&rsquo; shelf life.</span></span></div> Agar disk diffusion test, Broth microdilution method, Nanoemulsion, Rosemary essential oil, Steam phase diffusion method 79 85 http://jhehp.zums.ac.ir/browse.php?a_code=A-10-47-5&slc_lang=en&sid=1 Hassan Hassanzadazar Hassanzadazar_h@zums.ac.ir 10031947532846009711 10031947532846009711 Yes Department of Food Safety and Hygiene, School of Public Health, Zanjan University of Medical Science, Zanjan, Iran. Samira Yousefizadeh s.yousefizadeh1992@gmail.com 10031947532846009712 10031947532846009712 No Student Research Committee, School of Public Health, Zanjan University of Medical Science, Zanjan, Iran. Azadeh Ghafari aghaffari@zums.ac.ir 10031947532846009713 10031947532846009713 No Department of Food and Drug Control, School of Pharmacy, Zanjan University of Medical Science, Zanjan, Iran. Mehdi Fathollahi Mehdi_fathollahi65@yahoo.com 10031947532846009714 10031947532846009714 No Department of Food Safety and Hygiene, School of Public Health, Zanjan University of Medical Science, Zanjan, Iran. Majid Aminzare m.aminzare@zums.ac.ir 10031947532846009715 10031947532846009715 No Department of Food Safety and Hygiene, School of Public Health, Zanjan University of Medical Science, Zanjan, Iran.