부산대학교 도서관

ABSTRACTMultidrug-resistant Acinetobacter baumanniihas emerged as a problematic hospital-acquired pathogen. It is vital to search for new sources of antibiotics. Natural plant essential oils have several biological properties, including antimicrobial activity and may be valuable for new drug development. Chemical composition of the essential oil of Nectandra megapotamicaflowers was assessed by Gas Chromatography/Flame Ionization Detector and Gas Chromatography/Mass Spectrometry analysis. Antibacterial activity against OXA-23-producing A. baumanniiand synergism with antibiotics were performed by broth microdilution, time kill, and checkerboard methods. The essential oil of Nectandra megapotamicaflowers showed a predominance of oxygenated sesquiterpenes and caryophyllene oxide was the main component. Survival curves showed a linear decrease in viable OXA-23-producing A. baumanniicell counts over time for the association between the essential oil of Nectandra megapotamicaflowers and imipenem. Checkerboard assay with imipenem presented Fractional Inhibitory Concentration Index of 0.156, suggesting synergism. The synergistic effect of essential oil of Nectandra megapotamicaflowers with imipenem could be a potential approach to combat multiresistant OXA-23-producing A. baumanniistrains, and could be used as a drug delivery system, as an excipient for imipenem, reducing its dosage.