In-vitro antibacterial activity of Cymbopogon citratus (DC.) Stapf. and Eucalyptus globulus Labill

Background: Sarcoptic mange and associated secondary infections are challenges in improving productivity and production of goats in Ethiopia. Objective: The present study has aimed at evaluating efficacy of essential oils from two plant species against opportunistic bacterial pathogens in mange infested goats. Materials and methods: Essential oils (EOs) were obtained through hydrodistillation of freshly collected Cymbopogon citratus and Eucalyptus globulus leaves. Serial dilutions (20% to 0.3125%) of the EOs were tested for their antibacterial activity against Staphylococcus aureus, S. hyicus and S. intermidius using agar well diffusion and agar dilution methods and compared with standard antibiotics, erythromycin and chloramphenicol. Results: Cymbopogon citratus and E. globulus EOs showed significant and dose dependent antibacterial activity. Essential oil of C. citratus was more potent than E. globulus; and S. hyicus was the most sensitive at 10% concentration. The EOs (10%) have comparable potency with the standard antibiotics. The minimum inhibitory concentration was found to be 0.125% v/v of C. citratus and 0.5% v/v of E. globulus EOs for all tested bacteria. Conclusion: The two EOs showed strong antimicrobial property against the tested bacteria. However, further study is warranted to identify the specific potential EO combinations responsible for the effect, and formulation into appropriate dosage forms.