Navid Saidi - Molecular Microbiology Research Center, Shahed University, Tehran, Iran.
Fatemeh Sefidkon - Research Institute of Forests and Rangelands, Tehran, Iran.
Elaheh Taghian - Molecular Microbiology Research Center, Shahed University, Tehran, Iran.
Horieh Saderi - Molecular Microbiology Research Center, Shahed University, Tehran, Iran.
Iraj Rasooli - Molecular Microbiology Research Center, Shahed University, Tehran, Iran.
Parviz Owlia - Molecular Microbiology Research Center, Shahed University, Tehran, Iran.

Introduction and Objectives: P. aeruginosa is one of the most common opportunistic bacteria in nosocomial infections, which has a significant resistance to antimicrobial agents. Due to restrictions in the use of antibiotics, the tendency to replace them with natural products is increasing. In this study, evaluated the antimicrobial effects of 4 species of Satureja essential oils (S. mutica, S. bachtiarica, S. rechingeri jamzad and S. khuzestanica) on virulence factors of P. aeruginosa. Materials and Methods: The minimum inhibitory concentration of Satureja essential oils was determined by microdilution broth method against standard strains of P. aeruginosa PAO1 and P. aeruginosa 8821M. In the following, the effects of Sub-MIC concentrations of essential oils were investigated on motility, biofilm formation, alginate, elastase and alkaline protease production of these two strains. Results: Each of the four Satureja essential oils had antimicrobial effects against standard strains of P. aeruginosa, and also sub-MIC concentrations of the extracts significantly reduced the virulence factors production of these strains. Meanwhile, S. khuzestanica had the most antimicrobial activity. Conclusion: In this study, the antagonistic effects of Satureja essential oils were observed against P. aeruginosa. By further study, these essential oils can be used as an antimicrobial compound against this bacterium.

Essential oils, Pseudomonas aeruginosa, Virulence factors, Satureja.