期刊
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
卷 439, 期 1, 页码 148-153出版社
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI: 10.1016/j.bbrc.2013.08.001
关键词
epsilon-Poly-L-lysine; Escherichia coli O157:H7; Antibacterial mechanism; Reactive oxygen species; Real-time quantitative PCR
资金
- Twelfth Five-Year Plan for National Science and Technology Support Program [2011BAK10B06, 2011BAK10B01, 2011BAK10B02]
- State Key Laboratory of Food Science and Technology, Nanchang University [SKLF-TS-200916]
epsilon-Poly-L-lysine (epsilon-PL)c(2) is widely used as an antibacterial agent because of its broad antimicrobial spectrum. However, the mechanism of epsilon-PL against pathogens at the molecular level has not been elucidated. This study investigated the antibacterial activity and mechanism of epsilon-PL against Escherichia coli O157:H7 CMCC44828.-Propidium monoazide-PCR test results indicated that the threshold condition of epsilon-PL for complete membrane lysis of E. coli O157:H7 was 10 mu g/mL (90% mortality for 5 mu g/mL). Further verification of the destructive effect of epsilon-PL on cell structure was performed by atomic force microscopy and transmission electron microscopy. Results showed a positive correlation between reactive oxygen species (ROS)(3) levels and epsilon-PL concentration in E. coli O157:H7 cells. Moreover, the mortality of E. coli O157:H7 was reduced when antioxidant N-acetylcysteine was added. Results from real-time quantitative PCR (RT-qPCR)(4) indicated that the expression levels of oxidative stress genes sodA and oxyR were up-regulated 4- and 16-fold, respectively, whereas virulence genes eaeA and espA were down-regulated after E-PL treatment. Expression of DNA damage response (SOS response)(5) regulon genes recA and lexA were also affected by E-PL. In conclusion, the antibacterial mechanism of E-PL against E. coli O157:H7 may be attributed to disturbance on membrane integrity, oxidative stress by ROS, and effects on various gene expressions, such as regulation of oxidative stress, SOS response, and changes in virulence. (C) 2013 Published by Elsevier Inc.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据