Mohaddese Mahboubi, Nastaran Kazempour and Mohsen Taghizadeh

pp. 513 - 519

Abstract

Acinetobacter baumannii is categorized as a red alert pathogen that is increasingly associated with a high mortality
rate in infected patients due to its resistance to extensive antibiotics. In this study, we evaluated the antibacterial activities of
some essential oils (Oliveria decumbens, Pelargonium graveolens, Eugenia caryophyllata, Ziziphora tenuir and
Trachyspermum copticum oils) against 32 clinical isolates of A. baumannii. The antibacterial evaluations and chemical composition of essential oils was determined. Thymol, eugenol, α-terpineol, α-citronellol and thymol were the chief portions of
T. copticum, E. caryophyllata, Z. tenuir, O. decumbens and P. graveolens oils, respectively. The MIC values of oils against
these clinical isolates revealed the three subsets of oils including 1- T. copticum, E. caryophyllata and O. decumbens,
2- Z. tenuir and 3- P. graveolens oils. These oils showed the synergistic activity with amikacin, the lower Fractional Inhibitory
Concentration Index (FICI) was for P. graveolens oil (0.23) and the higher FICI was for E. caryophyllata (0.325).

Keywords

• essential oils
• antibacterial activity
• isobologram curve
• Acinetobacter baumannii