Tehran University of Medical Sciences Journal of Medical Bacteriology 2251-8649 7 1-2 2018 05 15 44 49 EN Mariia Kokina Department of Technology of Microbiological Synthesis, Saint Petersburg State Institute of Technology (Technical University), Saint Petersburg, Russian Federation. Mark Shamtsyan Faculty of Agriculture Science, Food Industry and Environmental Protection, Lucian Blaga University of Sibiu, Romania. Cecilia Georgescu Faculty of Agriculture Science, Food Industry and Environmental Protection, Lucian Blaga University of Sibiu, Romania. Monica Mironescu Faculty of Agriculture Science, Food Industry and Environmental Protection, Lucian Blaga University of Sibiu, Romania. 2018 05 21 2018 05 21 Background:       it is known that plants have many potential benefits for human health. The purpose of this study was to investigate the antimicrobial properties of several commonly used herbs against specific microorganisms responsible for disease and food spoilage. Essential oils of yarrow, fennel, juniper and marjoram were evaluated, with respect to their efficacy at controlling the growth and survival of several common bacterial and fungal microorganisms. Methods:     The agar diffusion test was used to test the essential oils efficacy at inhibiting microbial growth. The following microorganisms were tested with varied results: Escherichia coli, Aspergillus niger, Enterococcus faecalis, Salmonella typhimurium, Salmonella anatum, Staphylococcus aureus, Candida albicans, Penicillium glaucum and Bacillus cereus. Results:      Marjoram showed the highest inhibition with a zone up to 14 mm. Juniper and fennel essential oils were also highly inhibitory to Candida albicans and the other tested bacteria and fungi. Conclusion:       In conclusion, some of the oils were highly effective at inhibiting the studied microorganisms. This knowledge may be useful for further examining the efficacy of pathogenic prevention and food preservation by studied essential oils. https://jmb.tums.ac.ir/index.php/jmb/article/view/375 https://jmb.tums.ac.ir/index.php/jmb/article/download/375/258