Bactericidal and Bacteriostatic effect of sesame oil, olive oil and their synergism on Escherichia coli in vitro

Escherichia coli is one of the important bacteria in nosocomial infections and its resistance to a wide range of antibiotics caused many problems for doctors and patients. So, it was attempted to find new substitution for these antibiotics. The aim of the present study was to determine the antimicrobial effect of olive oil, sesame oil and their synergism on E. coli.
In this study, olive oil and sesame oil were extracted by cold press assay and standard strain of lyophilized E. coli ATCC 25922 was prepared from the Iranian Research Organization for Science and Technology. Olive oil, sesame oil and their synergism, with the same proportion, in concentrations of 2 mg/ml to 1024 mg/ml were made individually and their MBC and MIC amounts were determined by broth micro dilution.
This study declared MIC and MBC for olive oil; 16 mg/ml and 64 mg/ml, for sesame oil and their mixture; 64 mg/ml and 265mg/ml, respectively.
The study showed that both oils and their synergism inhibits the growth of bacteria and the antibacterial properties of sesame oil is approximately equal to the mixture of olive oil and sesame oil and although the oils have good antibacterial effect, there was no synergetic effect in these oils.