Identification of hydrogen peroxide production-related genes in Streptococcus sanguinis and their functional relationship with pyruvate oxidase
Identification of hydrogen peroxide production-related genes in Streptococcus sanguinis and their functional relationship with pyruvate oxidase
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DOI：
10.1099/mic.0.039669-0
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发表时间：
2011-01-01
期刊：
影响因子：
2.8
通讯作者：
Xu, Ping
中科院分区：
文献类型：
--
作者：
Chen, Lei;Ge, Xiuchun;Xu, Ping
过氧化氢（H2 O2）是链球菌属（Streptococcus）的一种重要代谢产物，在口腔生物膜等微生物群落中起着重要的毒力和拮抗作用。编码丙酮酸氧化酶的spxB基因参与许多链球菌物种中的H2 O2产生。然而，关于它的调控以及与参与同一途径的其他基因的关系的知识是有限的。在这项研究中，三个基因ackA，spxR和tpk -被确定为有助于H2 O2生产血链球菌通过筛选突变体不透明的菌落外观。所有三个基因的突变导致H2 O2产量显著下降，为野生型的16-31%。补充菌株中H2 O2的产生得到恢复。这三株S.在平板培养和液体培养中，血吸虫突变体的表达量均降低，表明这三个基因在赋予血吸虫竞争优势中起着关键作用。吸血鬼qPCR分析表明，spxB的表达在ackA和spxR突变体中降低，而在tpk突变体中显著增加。
Hydrogen peroxide (H2O2), an important substance produced by many members of the genus Streptococcus, plays important roles in virulence and antagonism within a microbial community such as oral biofilms. The spxB gene, which encodes pyruvate oxidase, is involved in H2O2 production in many streptococcal species. However, knowledge about its regulation and relation with other genes putatively involved in the same pathway is limited. In this study, three genes ackA, spxR and tpk - were identified as contributing to H2O2 production in Streptococcus sanguinis by screening mutants for opaque colony appearance. Mutations in all three genes resulted in significant decreases in H2O2 production, with 16-31% of that of the wild-type. H2O2 production was restored in the complemented strains. Antagonism against Streptococcus mutans by these three S. sanguinis mutants was reduced, both on plates and in liquid cultures, indicating the critical roles of these three genes for conferring the competitive advantage of S. sanguinis. Analysis by qPCR indicated that the expression of spxB was decreased in the ackA and spxR mutants and significantly increased in the tpk mutant.