Agar well diffusion Tubes of 20 ml sterile liquid nutrient agar (OXOID) at 50◦Cwere inoculated with 500 l of 7 log CFU/ml Staphylococcus aureus (overnight cultures grown at 37◦C on nutrient broth, and plated out in nutrient agar media to take colony count), mixed thoroughly ,poured into sterile empty plates and left 1 hour at room temperature until solidification.