Bactericidal effects of essential oils from clove, lavender and geranium on multi-drug resistant isolates of Pseudomonas aeruginosa

Document Type : Brief Report


1 Laboratory for Microbiology, Barij Essence Pharmaceutical Industry, P.O. BOX 1178, Kashan, I.R. Iran.

2 Department of Microbiology, Pasteur Institute of Iran, P.O. BOX 13164, Tehran, I.R. Iran.

3 Department of Microbiology, School of Medicine, Tehran University of Medical Science, P.O. BOX 14155-5983 Tehran, I.R. Iran.


The inhibitory effects of essential oils including clove, lavender and geranium extracted from Eugenia caryophyllata, Lavandula officinalis and Pelargonium graveolens on multidrug resistant isolates of Pseudomonas aeruginosa were investigated. The main constituents of clove, lavander and geranium oil were eugenol (80-90%), 1,8-cineol (13%) and citronellol (45%) respectively. Clove had the most effective essential oil against P. aeruginosa. A combination consisting of clove, lavender and geranium oils at a ratio of 3:1:1
showed the most inhibitory effect (32-64 μg/ml) and strong synergy with gentamicin. The essential oils from clove, lavender and geranium exhibited bactericidal activity against multi-drug resistant strains of P.aeruginosa and may be alternatives compounds against these strains in the future.