Antibacterial Effect of Allium sativum and Rosmarinus officinalis Essential Oil on Major Mastitis Pathogens in Dairy Cattle

In this research, the antibacterial effects of essential oil of two medicinal plants, Allium sativum and Rosmarinus officinalis were studied on Staphylococcus agalactiae, S. aureu and Escherichia coli Essential oils were prepared from department of medical plants of Arak University. The antibacterial properties of the essences were investigated by disk diffusion method in different concentrations of the essences (10, 30 and 50%). MIC and MBC were determined by using different concentrations of essences. Antibacterial activity of Penicillin, Bacitracin and Erythromycin was determined with the discs that were impregnated with antibiotics. All concentrations of the essential oil (10, 30 and 50%) had antibacterial effect. Antibacterial effects decreased according to reduction of essential oil concentrations. There were no significant difference between Allium sativum and Rosmarinus officinalis in MIC and MBC. There were, however, significant differences among mean zones of inhibition found in essential oils and antibiotics (Penicillin, Bacitracin and Streptomycin) at 10% concentration. According to antibacterial effect of Allium sativum and Rosmarinus officinalis essential oils on major bacterial mastitis pathogens in cow these plants has the potential to be evaluated as an alternative or adjunct to antibiotics to treat bovine mastitis.