Hydrogen Peroxide-Dependent DNA Release and Transfer of Antibiotic Resistance Genes in Streptococcus gordonii
Hydrogen Peroxide-Dependent DNA Release and Transfer of Antibiotic Resistance Genes in Streptococcus gordonii
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DOI：
10.1128/jb.05791-11
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发表时间：
2011-12-01
影响因子：
3.2
通讯作者：
Kreth, Jens
中科院分区：
文献类型：
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作者：
Itzek, Andreas;Zheng, Lanyan;Kreth, Jens
某些口腔链球菌在需氧生长条件下产生H2 O2，以抑制变形链球菌等竞争物种。此外，H2 O2的产生导致细胞外DNA（eDNA）的释放。eDNA可以参与几个重要的功能：生物膜形成和细胞-细胞聚集由eDNA支持，而eDNA可以作为营养素和通过螯合必需阳离子作为抗菌剂。eDNA包含具有转移基因组信息的潜力的大小的DNA片段。以格氏链球菌为模式生物，进一步研究了过氧化氢依赖的eDNA释放。在确定的生长条件下，eDNA的释放过程被证明是完全依赖于H2 O2。染色体DNA损伤似乎是释放的内在信号，尽管只有活跃生长的细胞是熟练的eDNA供体。有趣的是，eDNA的产生过程被发现与S.戈登自然能力系统因此，H2 O2的产生触发了抗生素抗性基因的转移。这些结果表明，H2 O2可能不仅仅是一种简单的有毒代谢副产物;相反，它的产生可以作为一种重要的环境信号，通过遗传信息的转移和突变率的增加来促进物种进化。
Certain oral streptococci produce H2O2 under aerobic growth conditions to inhibit competing species like Streptococcus mutans. Additionally, H2O2 production causes the release of extracellular DNA (eDNA). eDNA can participate in several important functions: biofilm formation and cell-cell aggregation are supported by eDNA, while eDNA can serve as a nutrient and as an antimicrobial agent by chelating essential cations. eDNA contains DNA fragments of a size that has the potential to transfer genomic information. By using Streptococcus gordonii as a model organism for streptococcal H2O2 production, H2O2-dependent eDNA release was further investigated. Under defined growth conditions, the eDNA release process was shown to be entirely dependent on H2O2. Chromosomal DNA damage seems to be the intrinsic signal for the release, although only actively growing cells were proficient eDNA donors. Interestingly, the process of eDNA production was found to be coupled with the induction of the S. gordonii natural competence system. Consequently, the production of H2O2 triggered the transfer of antibiotic resistance genes. These results suggest that H2O2 is potentially much more than a simple toxic metabolic by-product; rather, its production could serve as an important environmental signal that facilitates species evolution by transfer of genetic information and an increase in the mutation rate.