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Evidence-Based Complementary and Alternative Medicine
Volume 2013, Article ID 121407, 8 pages
Research Article

Different Effects of Six Antibiotics and Ten Traditional Chinese Medicines on Shiga Toxin Expression by Escherichia coli O157:H7

State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, 27 Shanda Nanlu, Jinan 250100, China

Received 7 April 2013; Revised 17 June 2013; Accepted 22 June 2013

Academic Editor: Jairo Kenupp Bastos

Copyright © 2013 Mei Ling Chen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


This study compared the effects of ten types of traditional Chinese medicines (TCMs) and six different antibiotics on E. coli O157:H7 Shiga toxin gene (stx2) mRNA expression level based on real-time PCR and the expression level of Stx toxin using an ELISA quantitative assay. We also compared their effects on the induction of the SOS response. The results clearly indicated that all ten TCMs had negative results in the SOS response induction test, while most TCMs did not increase the levels of stx2 mRNA and the Stx toxin. Some TCMs did increase the mRNA levels of the stx2 gene and the Stx toxin level, but their increases were much lower than those caused by antibiotics. With the exception of cefotaxime, the six antibiotics increased the Stx toxin level and increased the stx2 gene mRNA level. With the exceptions of cefotaxime and tetracycline, the antibiotics increased the SOS induction response. These results suggest that TCMs may have advantages compared with antibiotics, when treating E. coli O157:H7; TCMs did not greatly increase Stx toxin production and release.