Blepharis cuspidata, Boswellia ogadensis, and Thymus schimper essential oils were investigated for their antibacterial effects, efficacy was tested against multidrug resistance Escherichia coli, Klebsiella pneumoniae, and Methicillin resistant Staphylococcus aureus.
Extracts were placed in discs that contained either E. coli, K. pneumoniae, or MRSA for 19 hours. Minimum inhibitory concentration and minimum bactericidal concentration was assessed using micro-dilution, and interaction between EOs was measured using fractional inhibitory concentration complex. Antibacterial potential of these oils were found to be affected by the doses; types of oils used; and bacterial species used.
Combination of EOs T. schimperi and B. cuspidata was revealed to have an inhibition zone of 39mm and an MIC and MBC value of 0.39 microliters per milliliter of MRSA.
Against K.pneumoniae and E. Coli combined EOs had an inhibition zone between 28-35mm, and an MIC value ranging from 0.39-6.25 mcL/mL and an MBC ranging from 0.78-12.5 mcL/mL.
Combined EOs of B.ogadensis and B. cuspidata had a MIC value between 0.78-6.25 mcL/mL for K.pneumoniae and E. coli, and 1.56 mcL/mL for MRSA.
Combination of B. cuspidata and T. schimperi were found to have had the strongest synergistic effect among the EOs tested. Gram positive bacteria were noted to be more susceptible against the effects of the combined essential oils.
It was concluded that certain essential oil combinations have significant antibacterial properties which may be useful in combating MDR pathogens.
