Evaluation of Antibacterial Activity of Essential Oils and Their Combination against Multidrug-Resistant Bacteria Isolated from Skin Ulcer.

BACKGROUND

Emerging of multidrug-resistant bacteria can compromise the effectiveness of antibiotics used to treat skin infections. Those bacteria imposed public health problems and questioning medical care in the 21 century. In this circumstance, essential oils of medicinal plants origin are supreme sources of structural and functionally divergent compounds, which inhibited the growth of common wound colonizing MRSA and ESBL producing The aim of this study was to evaluate the combined antibacterial activity of essential oils extracted from and against multidrug-resistant (MDR) isolates of skin ulcers.

METHODS

Essential oils (EOs) were extracted from aerial parts of , and with steam distillation. A mixture of each oil (1 : 1) was adsorbed to a disc and placed on Mueller Hinton Agar. Then, minimum zone of inhibition and bactericidal concentration of EOs was measured after incubeted for 18-24 hours at 37 °C. Their combined antibacterial effect was determined by the fractional inhibitory concentration index.

RESULTS

The antibacterial activity of mixed oil varied in their doses and bacteria species, of which a mixture of essential oil of and had inhibition zone (32 mm); its MIC and MBC values range from 1-2 l/ml against MRSA. It had an inhibition zone (36 mm), MIC value 4 l/ml, and MBC (8 l/ml) against ESBL producing , whereas combined effects of and had MIC values ranging from 2-8 l/ml for and and 2 l/ml for MRSA. There was a strong synergistic effect between and and promising antibacterial effect more specifically on MRSA and . This in vitro study of the combined effect of EOs has significant antibacterial activity on wound colonizing bacteria and reduces delaying wound healing as that of modern drugs tested in parallel. Hence, further structural elucidation of active compounds helps us to properly design or synthesis of topical antibiotics for wound care.