Effect of Mitomycin C on the Expression of Shiga Toxin from Escherichia coli O157

【Objective】Effect of mitomycin C on the induction of the Stx-converting bacreriophages (Stx phages) and the expression of Shiga toxin (Stx) from Escherichia coli O157 was investigated. 【Method】 Bacteriophage was induced by mitomycin C from 8 strains of Escherichia coli serotype O157 and plaques were screened by two layers agar assy using the Escherichia coli MC1061 as indicator. PCR was used to identify the Stx phages. The production of Stx toxins which induced from Escherichia coli O157 was simultaneously measured by WST-1 cell proliferation and cytotoxicity assay kit. Toxin expression included four stages (before induction, after induction 8 h, 12 h and 16 h). 【Result】 The results of study showed that mitomycin C induced the release of Stx phages and the expression of Stx toxin from Escherichia coli O157 was apparently increased while induced by mitomycin C. The scope of increase was slower with the time of induction. 【Conclusion】Stx phages’ release and Stx toxin expression from Escherichia coli O157 may be increased while induced by mitomycin C. Therefore, the pathogenicity of germs will be enhanced.