Antibacterial activity of Citrus aurantium leaf essential oil against S.aureus and MRSA

Abstract

Plants based antimicrobials effective in the treatment of infectious diseases and also devoid of side effects which associated with synthetic one. To evaluate antibacterial effect of Citrus aurantium leaf essential oil against S.aureus and MRSA along with SEM approach. Disc diffusion and Microbroth dilution method were used to determine antibacterial effect of C. aurantium leaf essential oil and Linezolid was used as standard. Surface morphology of EO treated S.aureus and MRSA was demonstrated by Scanning Electron Microscope. Disc diffusion method showed zone of inhibition were 18 ± 0.2, 23± 0.13 & 26 ± 0.1mm at the concentration of 0.25, 0.5, 0.75 µl/disc for S.aureus respectively. Linezolid showed 24±0.2 mm. Zone of inhibition were 14±0.3, 16±0.2, 20±0.1mm at the concentration of 0.25, 0.5, 0.75 µl/disc for MRSA respectively. Linezolid showed 21±0.2mm against MRSA. MIC was determined for VO and Linezolid against S.aureus and MRSA were found to be 4, 6 µg/ml and 2, 4 µg/ml respectively by micro broth dilution test. SEM observation showed appearance of blast like bleb structures on the surface, irregular spherical structures and eventual cell ruptures of the bacterial cell wall in other words surface destruction of the MRSA with intervening spaces  have been resulted. Citrus aurantium leaf essential oil showed antimicrobial activity against S.aureus and MRSA.

Key words: Citrus aurantium, Essential oil (EO), Methicillin Resistant Staphyllococcus auerus (MRSA), Scanning Electron Microscope (SEM), Disc diffusion, Microdilution.