Tehran University of Medical Sciences Journal of Medical Bacteriology 2251-8649 8 1-2 2019 02 19 37 44 EN Saeide Saeidi Zabol Medicinal Plant Research Center, Zabol University of Medical Sciences, Zabol, Iran. Mahboubeh Mohsenbeygi Department of Biology, Faculty of Science, Shahid Bahonar University of Kerman, Kerman, Iran. Javad Roustakhiz Department of Plant Production, Higher Education Complex of Saravan, Iran Fereshteh Javadian Zabol Medicinal Plant Research Center, Zabol University of Medical Sciences, Zabol, Iran Mehdi Hassanshahian Department of Biology, Faculty of Science, Shahid Bahonar University of Kerman, Kerman, Iran. 2017 11 16 Background: The aim of this study was to investigate the antimicrobial and anti-biofilm effects of Mentha piperita and Zataria multiflora on some pathogenic bacteria. Methods: Mentha piperita and Zataria multiflora essential oils were obtained by using the clevenger device. The bacterial cultures were prepared as standard samples. Finally, antimicrobial and anti-biofilm activity was determined by microdilution method.                                                                                                                                    Results: The results of this study showed that the lowest inhibitory concentration of essential oil of Zataria multiflora was 1.25 mg / ml, while the rest of the bacteria were inhibited at a concentration of 2.5 mg / ml. The lowest and highest inhibitory concentrations were found as 1.25 and 5 mg / ml against Pseudomonas aeruginosa. Conclusion:The results of the study showed that Z. multiflora  essential oil showed antimicrobial and anti-biofilm activity that could be used to treat infections caused by these bacteria. https://jmb.tums.ac.ir/index.php/jmb/article/view/327 https://jmb.tums.ac.ir/index.php/jmb/article/download/327/279