1.Antimicrobial activity of essential oils of Curcuma longa and Syzygium aromaticum against multiple drug-resistant pathogenic bacteria
Zeshan, M.Q. ; Ashraf, M. ; Omer, M.O. ; Anjum, A.A. ; Ali, M.A. ; Najeeb, M. ; Majeed, J.
Tropical Biomedicine 2023;40(No.2):174-182
The present study was conducted to investigate the antimicrobial potential of essential oils of Curcuma
longa and Syzygium aromaticum against multidrug-resistant pathogenic bacteria. Four identified
bacterial isolates including Methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Klebsiella
pneumoniae, and Acinetobacter baumannii were selected and their antibiotic sensitivity was checked
by disc diffusion assay. C. longa and S. aromaticum were subjected to steam distillation to obtain their
essential oils. The crude essential oils were fractioned by employing column chromatography. Crude
essential oils and their fractions were evaluated for their antibacterial activity by agar well diffusion
assay and minimum inhibitory concentrations were calculated. All the selected bacterial isolates
showed resistance to three or more than three antibiotic groups and were declared as multidrugresistant (MDRs). Crude essential oils of C. longa and S. aromaticum exhibited antimicrobial activity
against all selected isolates but S. aromaticum activity was better than the C. longa with a maximum
19.3±1.50 mm zone of inhibition against A. baumannii at 1.04 µL/mL MIC. GC/MS analysis revealed
the abundance of components including eugenol, eugenyl acetate, b- caryophyllene, and a- Humulene
in both crude oil and fractions of S. aromaticum. While the main components of C. longa essential oil
were Ar-tumerone, a–tumerone, b- Tumerone, I-Phellandrene, a-zingibirene, b- sesquiphellandrene,
and p- Cymene. This study highlights that plant-based essential oils could be a promising alternative to
antibiotics for which pathogens have developed resistance. C. longa and S. aromaticum carry compounds
that have antimicrobial potential against multiple drug-resistant bacteria including MRSA. E. coli, K.
pneumoniae and A. baumannii.