Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 1 2 2009 06 15 43 48 EN M Mahboubi Research Center of Barij Essence Pharmaceutical Company, Kashan, Iran. N Farzin Research Center of Barij Essence Pharmaceutical Company, Kashan, Iran. 2015 10 01 Background and objectives: The Artemisia genus of Asteraceae family is represented by 34 species in Iran. Artemisia sieberi grows wild in different regions of Iran and grows in desert and semi- desert climate and has forage value for animals and also medicinal properties for humans. In this study we examined the antimicrobial effects of A. sieberi. Materials and Methods: The antimicrobial activity of A. sieberi essential oil was evaluated against different microorganisms including Gram positive bacteria, Gram negative bacteria, yeast and fungi by disc diffusion method and micro broth dilution assay. Results: The oil with main components of α- thujone, β- thujone and camphor showed antimicrobial activity against different microorganisms with varying types of pathogens. Gram positive bacteria and fungi were more sensitive than Gram negative ones. Among Gram positive bacilli, Listeria monocytogenes and Bacillus cereus and among Gram positive cocci, Streptococcus mutans were more sensitive than others. Conclusion:The antimicrobial properties of this oil showed that the A. sieberi essential oil has good potential use in the food and cosmetic industry. https://ijm.tums.ac.ir/index.php/ijm/article/view/17 https://ijm.tums.ac.ir/index.php/ijm/article/download/17/17