Characterizing RecA-independent induction of Shiga toxin2-encoding phages by EDTA treatment.
Characterizing RecA-independent induction of Shiga toxin2-encoding phages by EDTA treatment.
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DOI：
10.1371/journal.pone.0032393
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Muniesa M
中科院分区：
文献类型：
--
作者：
Imamovic L;Muniesa M
噬菌体生命周期在滋贺毒素（Stx）表达中具有重要作用。由于噬菌体基因组的复制，滋贺毒素编码酶（Stx β）的诱导增加了毒素的产生，并且宿主细胞的噬菌体裂解也提供了Stx毒素离开细胞的手段。以前的研究表明，原噬菌体诱导也可能发生在SOS反应的情况下，独立于RecA。EDTA对RecA非依赖性Stx2噬菌体诱导的影响通过实时PCR在实验室溶原菌和在其基因组中携带Stx2噬菌体的EHEC菌株中进行评估。针对噬菌体λ诱导（RcsA和DsrA）描述的RecA非依赖性机制不参与Stx2噬菌体诱导。此外，细菌包膜对EDTA的应激反应途径中的突变对Stx2噬菌体诱导没有贡献。EDTA对Stx噬菌体诱导的作用是由于其螯合性质，这也通过使用柠檬酸盐（另一种螯合剂）得到证实。我们的研究结果表明，EDTA影响Stx2噬菌体诱导的细菌外膜的破坏，由于螯合的Mg2+。在所有评价的条件中，pH值在Stx2噬菌体诱导中具有决定性作用。螯合剂，如EDTA和柠檬酸盐，诱导Stx降解，这引起了人们的关注，因为它们经常用于食品和药品。这项研究有助于我们理解的现象的诱导和释放的Stx的一个重要因素的致病性的滋贺毒素产生大肠杆菌（STEC）和新的致病菌株的出现。
The bacteriophage life cycle has an important role in Shiga toxin (Stx) expression. The induction of Shiga toxin-encoding phages (Stx phages) increases toxin production as a result of replication of the phage genome, and phage lysis of the host cell also provides a means of Stx toxin to exit the cell. Previous studies suggested that prophage induction might also occur in the absence of SOS response, independently of RecA. The influence of EDTA on RecA-independent Stx2 phage induction was assessed, in laboratory lysogens and in EHEC strains carrying Stx2 phages in their genome, by Real-Time PCR. RecA-independent mechanisms described for phage λ induction (RcsA and DsrA) were not involved in Stx2 phage induction. In addition, mutations in the pathway for the stress response of the bacterial envelope to EDTA did not contribute to Stx2 phage induction. The effect of EDTA on Stx phage induction is due to its chelating properties, which was also confirmed by the use of citrate, another chelating agent. Our results indicate that EDTA affects Stx2 phage induction by disruption of the bacterial outer membrane due to chelation of Mg2+. In all the conditions evaluated, the pH value had a decisive role in Stx2 phage induction. Chelating agents, such as EDTA and citrate, induce Stx phages, which raises concerns due to their frequent use in food and pharmaceutical products. This study contributes to our understanding of the phenomenon of induction and release of Stx phages as an important factor in the pathogenicity of Shiga toxin-producing Escherichia coli (STEC) and in the emergence of new pathogenic strains.
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影响因子：
4.4
作者：
Aertsen, A;Faster, D;Michiels, CW
通讯作者：
Michiels, CW
影响因子：
3.6
作者：
BASSLER, BL;WRIGHT, M;SILVERMAN, MR
通讯作者：
SILVERMAN, MR
影响因子：
9.4
作者：
Boerlin, P;McEwen, SA;Gyles, CL
通讯作者：
Gyles, CL
DOI：
10.1073/pnas.120163297
发表时间：
2000-06-06
影响因子：
11.1
作者：
Datsenko, KA;Wanner, BL
通讯作者：
Wanner, BL
影响因子：
3.8
作者：
Fuchs, S;Mühldorfer, I;Hacker, J
通讯作者：
Hacker, J