Antimicrobial Activity of Oils and Extracts of Cymbopogon citratus (Lemon Grass), Eucalyptus citriodora and Eucalyptus camaldulensis

The antimicrobial potentials of essential oils and extracts from the leaves of Cymbopogon citratus (Lemon grass), Eucalyptus citriodora and Eucalyptus camadulensis were tested on Salmonella typhi, Staphylococcus aureous and Escherichia coli. Both the water extract and freeze dried extract of these leaves were used. Zone of inhibition measurement showed that Eucalyptus citriodora oil was very effective against Salmonella typhi and found to suppress growth of the organism after 24 h of incubation. Similar observation was made with a combined extract of Eucalyptus citriodora oil and lemon grass oil. Lemon grass oil was observed to possess high antimicrobial activity on all the three organisms tested while Eucalyptus camadulensis is very active against Staphylococcus aureus. Both the freeze dried extracts and the viscous extracts possess slight antimicrobial activity while in all cases, the aqueous extracts have no effects on the organisms.