Chemical Composition andIn VitroEfficacy of Essential Oil of SevenArtemisiaSpecies Against ESBL Producing Multidrug-ResistantEscherichia coli

Chemical composition and antibacterial and antibiotic interacting activities of essential oils obtained from the flowering branchlets of seven Artemisia species grown in Iran were investigated. Antibacterial activity against multi-drug resistance extended-spectrum β-lactamase (ESBL) positive Escherichia coli was also investigated. Major compounds in different Artemisia oils were α-phellandrene in A. absinthium, camphor in A. annua, 1,8-cineol and borneol in A. kulbadica, β-thujone in A. persica, cis-verbenol in A. santolina and 1-phenyl-penta-2,4-diene in A. scoparia. Artemisia oils showed synergism with antibiotics, in particular ciprofloxacin and nitrofurantoin, against all 5 tested ESBL positive E. coli. A. santolina and A. kulbadica showed promising synergistic activity with antibiotics. Using bioautography, compounds such as cis-verbenol, trans-verbenol and ρ-cymene-8-ol were identified as active compounds of A. santolina, and β-pinene, 1,8-cineol and borneol as active components of A. kulbadica. Artemisia species have antibacterial activity against all tested resistant ESBL positive E. coli and potentiate the efficacy of antibiotics.