Inhibitory effect of thyme and basil essential oils, carvacrol, thymol, estragol, linalool and p-cymene towards Shigella sonnei and S-flexneri

There are a few reports on the antimicrobial activity of essential oils or their major constituents towards Shigella sp. The antimicrobial effect of basil and thyme essential oil and its major constituents thymol, p-cymene, estragol, linalool, and carvacrol was determined using the agar well diffusion assay. Thyme essential oil and thymol and carvacrol showed inhibition of Shigella sp. in the agar well diffusion method. The potential of thyme essential oil, thymol and carvacrol at 0.5% and 1.0% v/v for decontamination of lettuce was evaluated. A decrease of the shigellae was observed after washing with 0.5% while at 1% Shigella numbers dropped below the detection limit. However, the antimicrobial effect on a subsequent lettuce sample in the same decontamination solution was significantly decreased. In addition, application of thyme essential oil or thymol or carvacrol for decontamination is hampered by sensoric properties of the lettuce (browning, strong odour). (C) 2003 Elsevier Ltd. All rights reserved.