Antimicrobial activity of plant essential oils against the growth of Escherichia coli

Abstract

Plant essential oils a well known herbs that was widely used in traditional medicine and food preservation due to the antimicrobial properties. The present study aimed to evaluate the antimicrobial activities of natural essential oils alone and in combination with tetracycline antibiotic against E.coli growth. In this study the antimicrobial effects of rosemary (Rosemarinus officinalis), clove(Sygium aromaticus), cumin(Cuminum cyminum) and ginger(Zingiber officinale) were tested alone and with tetracycline at concentration of (1:1, 1:2, 1:5 and 1:10) w/v dilution concentration which incorporated into Muller Hinton Agar that inoculated with pure activated E.coli culture and incubated for 24 hours at 37°C , the inhibition zone diameter was recorded. The obtained result showed that clove and rosemary essential oil alone was indicated the antimicrobial action, while clove, rosemary and ginger in combination with tetracycline were exhibited much more antimicrobial action than in tetracycline positive control against E.coli growth. This study emphasize the antibacterial properties of rosemary, clove and ginger essential oils in combination with tetracycline against E.coli were much higher than that of tetracycline, such combinations can be recommended for therapeutic purpose and be used as alternative medicine.