Aerotolerance and peroxide resistance in peroxidase and PerR mutants of Streptococcus pyogenes
Aerotolerance and peroxide resistance in peroxidase and PerR mutants of Streptococcus pyogenes
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DOI：
10.1128/jb.182.19.5290-5299.2000
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发表时间：
2000-10-01
影响因子：
3.2
通讯作者：
Caparon, MG
中科院分区：
文献类型：
--
作者：
King, KY;Horenstein, JA;Caparon, MG
需氧条件下的存活对于许多细菌的致病性至关重要。为了研究过氧化氢酶阴性的化脓性链球菌的耐氧性和抗氧化应激的方法，我们使用了一种基于基因组学的方法来识别和鉴定两种过氧化物酶基因的同源物，编码烷基氢过氧化物酶（ahpC）和谷胱甘肽过氧化物酶（gpoA）。单突变体和双突变体在有氧条件下与野生型一样存活。然而，它们比野生型更容易受到百草枯和氢过氧化枯烯的生长抑制。此外，我们还证明了S.化脓性链球菌在用亚致死剂量的过氧化物处理时表现出可诱导的过氧化物抗性反应。这种抗性反应在ahpC和gpoA突变体中是完整的，但在缺乏PerR的突变体中则不然，PerR是枯草杆菌中包括ahpC和过氧化氢酶（katA）在内的几个基因的抑制子。因为我们的数据表明，这些过氧化物酶基因不是必需的耐氧性或诱导抗过氧化物胁迫在S。化脓性链球菌中，用于管理过氧化物应激的新机制的基因可能由链球菌中的PerR调节。
Survival in aerobic conditions is critical to the pathogenicity of many bacteria. To investigate the means of aerotolerance and resistance to oxidative stress in the catalase-negative organism Streptococcus pyogenes, we used a genomics-based approach to identify and inactivate homologues of two peroxidase genes, encoding alkyl hydraperoxidase (ahpC) and glutathione peroxidase (gpoA). Single and double mutants survived as well as the wild type under aerobic conditions. However, they were more susceptible than the wild type to growth suppression by paraquat and cumene hydroperoxide. In addition, we show that S. pyogenes demonstrates an inducible peroxide resistance response when treated with sublethal doses of peroxide. This resistance response was intact in ahpC and gpoA mutants but not in mutants lacking PerR, a repressor of several genes including ahpC and catalase (katA) in Bacillus subtilis. Because our data indicate that these peroxidase genes are not essential for aerotolerance or induced resistance to peroxide stress in S. pyogenes, genes for a novel mechanism of managing peroxide stress may be regulated by PerR in streptococci.