Evaluation of Antimicrobial Activity of Aqueous and Ethanolic Extracts of Leaves of Vitis vinifera Collected from Different Regions in Morocco

4 Abstract: Aqueous and ethanolic extracts of leaves of Vitis vinifera collected from different regions in morocco (Fez, Meknes, El Jadida, Skhirat and Marrakech), were evaluated for antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria and yeasts. The in vitro antimicrobial activity was performed by agar well diffusion method and the minimum inhibitory concentration (MIC) was determined by microtitration technique. The results indicated that, the aqueous extract of Vitis vinifera inhibited most of Gram-positive bacteria, as well as two Gram-negative bacteria, while the ethanolic extracts of Vitis vinifera leaves generally showed high inhibitory activity against different bacteria, it inhibited Gram-positive bacteria and some Gram-negative bacteria and they showed poor inhibitory activity against Salmonella spp and MICs values were between 25-100 µg/ml. Fez extract showed the best inhibition for the tested bacteria. There were no inhibitory effects of the aqueous extracts against all tested yeasts strains. All ethanolic extracts showed antifungal activity against one strain (Candida famata1) and the diameter of inhibition zone ranged from 9.3 to 14.3 mm, with MIC values for 50 µg/ml. These results indicate some benefits of this plant as antimicrobial, especially against Gram positive bacteria.