Poster Presenter

Effects of Sub-Inhibitory Concentrations of Some Essential Oils on Alginate Production and Biofilm Formation of Pseudomonas aeruginosa
Parviz Owlia, Laila Moein Najafabadi, Iraj Rasooli , Horieh Saderi

Background: Pseudomonas aeruginosa is one of important opportunistic pathogen that produces a serious virulence factors. The aim of this study was evaluate the effects of sub-MICs of some essential oils on alginate production and biofilm formation.

Methods: Minimal inhibitory concentrations (MIC) of essential oils of Zataria multiflora, Myrtus communis, Eucalyptus camaldulensis Mentha spicata and Cumminum cyminum were determined by macrodilution method. Alginate production and bilofilm formation in the present of sub-MICs (1/2, 1/4 and 1/8 MIC) of essential oils were determined in mucoid P. aeruginosa 8821M.

Results: The MICs of essential oils against P. aeruginosa for Z. multiflora, M. communis, E. camaldulensis, M.spicata and C. cyminum oils were 64, 64, 64, 16 and 32μg/ml respectively. The results show that all oils at 1/2 and 1/4 MICs were significantly reduced alginate production and biofilm formation. At 1/8 MICs, Z. multiflora, C. cyminum and M. communis oils had significantly reduced alginate production and biofilm formation, but biofilm formation. E. camaldulensis oil in 1/8 MIC, had not significantly effects on biofilm formation.

Conclusion: This study showed that sub-MIC levels of Z. multiflora, M. communis, E. camaldulensis, M. spicata and C. cyminum essential oils affected alginate production and biofilm formation and it is probable to use of these medicinal plants as antimicrobial agent.