Characterization of Clostridium perfringens spores that lack spoVA proteins and dipicolinic acid
Characterization of Clostridium perfringens spores that lack spoVA proteins and dipicolinic acid
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DOI：
10.1128/jb.00325-08
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发表时间：
2008-07-01
影响因子：
3.2
通讯作者：
Sarker, Mahfuzur R.
中科院分区：
文献类型：
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作者：
Paredes-Sabja, Daniel;Setlow, Barbara;Sarker, Mahfuzur R.
产气荚膜梭菌孢子具有很高的耐热性，当这些孢子发芽并恢复活跃生长时，它们会引起胃肠道疾病。与枯草芽孢杆菌的研究表明，孢子的二吡啶酸（DPA）水平可以显著影响孢子的萌发和抗性，并且由spoVA操纵子编码的蛋白质对孢子在孢子形成过程中吸收DPA是必不可少的。我们现在发现，由spoVA操纵子编码的蛋白质在产气荚膜荚膜杆菌孢子形成过程中对Ca2+和DPA的吸收也是必不可少的。一个spoVA突变体孢子的Ca2+和DPA含量很少，其核心含水量大约是野生型孢子的两倍。这些不含dpa的孢子不能像不含dpa的枯草芽孢杆菌孢子那样自发发芽。事实上，野生型和spoVA产气荚膜荚膜菌孢子在l -天冬酰胺和KCl （AK）的混合物、KCl单独或1:1的Ca2+和DPA的螯合物（Ca-DPA）下发芽相似。而产气荚膜芽孢杆菌孢子活力比野生型孢子活力低20倍。在AK、KCl或外源Ca-DPA的作用下，脱壳的野生型和spoVA孢子几乎没有萌发，而且它们的集落形成效率比完整孢子低10(3)到10(4)倍。然而，溶菌酶处理挽救了这些脱壳孢子。尽管孢子中具有dna保护作用的α / β型、小的酸溶性孢子蛋白水平与野生型孢子相似，但孢子对湿热、甲醛、盐酸、过氧化氢、亚硝酸和紫外线辐射的抗性明显低于野生型孢子。综上所述，这些结果表明：(i)产气荚膜荚膜菌孢子形成过程中孢子吸收Ca-DPA所必需的SpoVA蛋白。（ii）产气荚膜荚膜菌孢子萌发不需要SpoVA蛋白和Ca-DPA的释放。（三）低的孢子核心含水量对产气荚膜荚膜芽孢杆菌孢子充分抵抗湿热、紫外线辐射和化学物质至关重要。
Spores of Clostridium Perfringens possess high heat resistance, and when these spores germinate and return to active growth, they can cause gastrointestinal disease. Work with Bacillus subtilis has shown that the spore's dipicolinic acid (DPA) level can markedly influence both spore germination and resistance and that the proteins encoded by the spoVA operon are essential for DPA uptake by the developing spore during sporulation. We now find that proteins encoded by the spoVA operon are also essential for the uptake of Ca2+ and DPA into the developing spore during C. perfringens sporulation. Spores of a spoVA mutant had little, if any, Ca2+ and DPA, and their core water content was approximately twofold higher than that of wild-type spores. These DPA-less spores did not germinate spontaneously, as DPA-less B. subtilis spores do. Indeed, wild-type and spoVA C. perfringens spores germinated similarly with a mixture of L-asparagine and KCl (AK), KCl alone, or a 1:1 chelate of Ca2+ and DPA (Ca-DPA). However, the viability of C.perfringens spoVA spores was 20-fold lower than the viability of wild-type spores. Decoated wild-type and spoVA spores exhibited little, if any, germination with AK, KCl, or exogenous Ca-DPA, and their colony-forming efficiency was 10(3)- to 10(4)-fold lower than that of intact spores. However, lysozyme treatment rescued these decoated spores. Although the levels of DNA-protective alpha/beta-type, small, acid-soluble spore proteins in spoVA spores were similar to those in wild-type spores, spoVA spores exhibited markedly lower resistance to moist heat, formaldehyde, HCl, hydrogen peroxide, nitrous acid, and UV radiation than wild-type spores did. In sum, these results suggest the following. (i) SpoVA proteins are essential for Ca-DPA uptake by developing spores during C. perfringens sporulation. (ii) SpoVA proteins and Ca-DPA release are not required for C. perfringens spore germination. (iii) A low spore core water content is essential for full resistance of C. perfringens spores to moist heat, UV radiation, and chemicals.