Abstract
The effect of Prunus mume Sieb. et Zucc.(Prunus mume) extract on the production of verotoxins by enterohemorrhagic Escherichia coli O157: H7 (EHEC) was investigated. The amount of vero-toxins (ng/ml) produced was calculated and revised according to the ratio between the amount of vero-toxins detected in the test tube and the viable cell numbers of EHEC. Production of EHEC vero-toxins was inhibited by the extract of the fruit of Prunus mume at 156 mg/ml. This inhibitory effect was obtained at a dose below the minimal inhibitory concentration (625 mg/ml) of the Prunus mume extract, indicating that this extract seems to act on the vero-toxin-producing cells of EHEC before vero-toxins are produced.