Title : Effect of some essential oils on mastitis pathogens
Abstract:
The present study deals with the evaluation of the antioxidant activity and the antimicrobial activity of 12 essential oils of local aromatic plants which are traditionally used in Algeria against 9 microbial strains responsible for dairy animal breast infections in order to select the most interesting oils. Physicochemical properties such as Refractive index and density are determined to assess the quality of the studied oils. Density of Eugenol and clove oil are greater than 1 (1.06 and 1.0019 respectively). Clove oil density is reported to be higher than the density of water. Antioxidant activity of the extracts was evaluated by three methods: reducing power by TPTZ method, DPPH and ABTS free radical scavenging. Thymol and eugenol displayed remarkable free radical scavenging properties. The antimicrobial activity of the tested oils was evaluated by biofilm formation inhibition using crystal violet assay which revealed that the 5 oils mentioned above have a strong inhibitory activity towards the preliminary formation of biofilm, clove proved to be the most active towards the primary formation of biofilm and its removal once formed. The essential oils of thymus vulgaricus, origanum vulgare, syzygium aromaticicum, as well as eugenol and thymol showed significant antioxidant activity compared to other oils tested. Clove oil (syzygium aromaticicum) showed the best antibiofilm activity, especially that formed by Staphylocuccus aureus.
