Antimicrobial activity of essential oils-derived volatile compounds against several nosocomial pathogens including representative multidrug-resistant A. baumannii clinical isolates

Abstract

The aim was to evaluate the antimicrobial activity of essential oils-derived volatile compounds against nosocomial pathogens, including representative multidrug-resistant (MDR) Acinetobacter baumannii clinical isolates. Minimum inhibitory dose (MID) values for the compounds were determined by the gaseous contact assay. A. baumannii representative clones were selected by pulsed-field gel electrophoresis. MDR profiles were determined by microdilution assay. Drug-resistant genes were detected by PCR. Biofilm production was determined by the crystal violet method. From all tested compounds, carvacrol had markedly lower MIDs (3.89–48.8 mg/L) against A. baumannii than against the other nosocomial MDR pathogens. The lowest MID was detected against three strains, which were obtained from different specimen types, had high drug resistance profiles and showed variable biofilm production. The work herein provides evidence that carvacrol may have therapeutic potential as a treatment for MDR A. baumannii infections.

Keywords:

• Acinetobacter baumannii
• multidrug resistance
• essential oils
• carvacrol