Antimicrobial effect of clove alcoholic extract and essential oil on Escherichia coli O157: H7

The importance of using different medicinal plants indicates their health and valuable effects such as antioxidant, antimicrobial, anti-inflammatory effects and etc. In this research, the effect of alcoholic extract and essential oil of Syzygium aromaticum on Escherichia coli was investigated. The effect of the plant on this microorganism as a gram negative was evaluated and important indicator of poisoning and diarrhea at levels of 3, 4, 5, 6, 7, 8 and 9 mg/ml of broth culture media. By dilution method using liquid culture media, minimum growth inhibitory concentration and minimum bactericidal concentration were determined. The results of this study indicated increasing the concentration of extract and essential oil in the studied area increased their antibacterial effect and the most inhibitory effect was on essential oil which means that the minimum inhibitory concentration for ethanolic extract and essential oil was 8 and 6 mg/ml, respectively. Similar results were observed in relation to MBC. Also, by comparing the obtained results, it was deduced that the inhibitory effect of the essential oil used in this study on E. coli was greater than the clove extract and the essential oil of the cloves had a more antibacterial role than extract. Eugenol, eugenol acetate, cavicol and beta-caryophyllene were observed in GC-MS analysis and the difference in the content of bioactive ingredient eugenol further confirmed this antimicrobial effect.