A comparative study of the in vitro antimicrobial and antifungal effect of Trachyspermumammi ,Lavandulaangustifolia and Eugenia aromatica essence on rainbow trout some patoghen

Regarding the revealing side effect of chemical medications, such as antimicrobial resistance and etc, herbal medications have been considered as one of potential alternative to chemical one. The main purpose of this study was to evaluate the in vitro antibacterial effect of lavender ( Lavandula angustifolia) and ajwain ( Trachyspermum ammi) essential oil on two important rainbow trout bacteria; streptococcus iniae and Lactococcus garvieae .In addition, antifungal activity of Clove (Eugenia aromatic) and lavender essential oil were assessed as well. Disc diffusion method was used to test antibacterial activity. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by using standard procedure Broth- microdilution. The results obtained demonstrated that Streptococcus iniae and Lactococcus garvieae were most sensitive to ajwain with inhibition zone of respectively 26±1mm & 24.33±1.15mm , which was significantly higher than amoxicillin , erythromycin and lavender (p<0.05). Moreover, ajwan essential oil showed the lowest MIC (0.049±0.01) compared to the other group. Antifungal activity of clove oil and lavender did not show significant difference comparing to Clotrimazol. However, these two herbal agents could not compete with Amphotericin b whith the highest zone of inhibition (13mm) (p<0.05). Therefore clove oil , lavender and ajwain essentialsare suggested as natural anti fungus and anti bacteria agents in aquaculture activities.