Evaluation of combined antibacterial effects of eugenol, cinnamaldehyde, thymol, and carvacrol against E. coli with an improved method.

In this study, the antibacterial activities of eugenol, cinnamaldehyde, thymol, carvacrol, and their combinations against E. coli were investigated separately. First, broth macro-dilution assay was adopted to determine the minimal inhibitory concentration (MIC) of the 4 components.