Antibacterial Activity of Essential Oils and Extracts of Some Medicinal Plants against Bacterial Fish Pathogens

In this study, chemical compositions and in vitro antibacterial activities the components of essential oils and extracts of sage (Salvia officinalis L.), rosemary oil (Rosmarinus officinalis L.), lavandin (Lavandula x intermedia var. Super), and hyssop (Hyssopus officinalis L.) against fish pathogens: Gram-negative bacteria (Aeromonas caviae, Aeromonas hydrophila, Vibrio anguillarum, Yersinia ruckeri, Edwardsiella tarda, Pseudomonas aeruginosa) and Gram-positive bacteria (Lactococcus garvieae, Staphylococcus warneri, Vagacoccus salmoninarum) were investigated with Well Diffusion Agar assay. The composition of the essential oils and extracts were analyzed with GC/MS and HPLC, respectively. A total of 42 components in sage, 39 in rosemary, 44 in lavender, and 46 in hyssop were detected. As a result of this study, the sage and rosemary oils exhibited a broad-spectrum inhibitory effect (a strong antibacterial effect against Gram (+) and Gram (-) pathogens). Lavandin oil also showed a strong antibacterial effect against a majority of pathogens. The spectrum of inhibitory activity of hyssop oil was found narrower than other plant oils. In further studies, in vivo antibacterial effects of sage, rosemary and lavandin essential oils should be investigated.