Functional characterisation of germinant receptors in Clostridium botulinum and Clostridium sporogenes presents novel insights into spore germination systems.
Functional characterisation of germinant receptors in Clostridium botulinum and Clostridium sporogenes presents novel insights into spore germination systems.
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DOI：
10.1371/journal.ppat.1004382
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发表时间：
2014-09
期刊：
影响因子：
6.7
通讯作者：
Peck MW
中科院分区：
文献类型：
--
作者：
Brunt J;Plowman J;Gaskin DJ;Itchner M;Carter AT;Peck MW
肉毒杆菌是一种危险的病原体，可形成高效力的肉毒杆菌毒素，摄入后会导致致命的神经麻痹性疾病。密切相关的产孢梭菌偶尔会致病，经常与食物腐败有关，被认为是 I 类肉毒梭菌的非产毒等价物。这两个物种都会形成在环境中普遍存在的高度抗性孢子，并且在有利的生长条件下发芽产生营养细胞。为了提高对形成肉毒杆菌神经毒素的梭菌的控制，必须了解孢子萌发的机制。位于孢子内膜的特定萌发受体 (GR) 识别小分子（萌发剂）后，萌发开始。本研究精确定义了梭菌 GR、萌芽体和共萌芽体。 I 组肉毒梭菌 ATCC3502 含有两个三顺反子和一个五顺反子 GR 操纵子，而产芽孢梭菌 ATCC15579 则含有三个三顺反子和一个四顺反子 GR 操纵子。插入敲除突变体与重组 GR 的表征相结合，首次表明肉毒杆菌中氨基酸刺激的萌发需要两个三顺反子编码的 GR，它们协同作用，不能单独发挥作用。 C. sporogenes 中的孢子萌发需要一个三顺反子 GR。另外两种 GR 构成了参与控制氨基酸刺激发芽率的复合体的一部分。讨论了在发芽研究和食物挑战测试中使用产芽孢梭菌作为肉毒杆菌替代品的适用性。 肉毒杆菌是一种危险的病原体，可形成致命的肉毒杆菌神经毒素。肉毒杆菌菌株以孢子形式存在于环境中。在适宜的条件下，细菌芽孢的休眠被打破，发生萌发。位于孢子内的特定萌发受体 (GR) 识别小分子后，萌发开始。目前，这些遗传资源的鉴定和表征仍然未知，但如果要制定策略来完全阻止孢子萌发，或使所有孢子萌发然后灭活新兴的敏感营养细胞，则至关重要。本研究表征了肉毒梭菌中两种具有协同作用且不能单独发挥作用的功能活性GR，以及产芽孢梭菌中的一种相关功能活性GR。这些 GR 对氨基酸有反应。其他遗传资源似乎是参与控制发芽速度的复合体的一部分，或者没有功能活性。这项研究为发芽机制提供了新的见解，并使我们能够制定新的策略来控制这种致命的病原体。
Clostridium botulinum is a dangerous pathogen that forms the highly potent botulinum toxin, which when ingested causes a deadly neuroparalytic disease. The closely related Clostridium sporogenes is occasionally pathogenic, frequently associated with food spoilage and regarded as the non-toxigenic equivalent of Group I C. botulinum. Both species form highly resistant spores that are ubiquitous in the environment and which, under favourable growth conditions germinate to produce vegetative cells. To improve the control of botulinum neurotoxin-forming clostridia, it is imperative to comprehend the mechanisms by which spores germinate. Germination is initiated following the recognition of small molecules (germinants) by a specific germinant receptor (GR) located in the spore inner membrane. The present study precisely defines clostridial GRs, germinants and co-germinants. Group I C. botulinum ATCC3502 contains two tricistronic and one pentacistronic GR operons, while C. sporogenes ATCC15579 has three tricistronic and one tetracistronic GR operons. Insertional knockout mutants, allied with characterisation of recombinant GRs shows for the first time that amino acid stimulated germination in C. botulinum requires two tri-cistronic encoded GRs which act in synergy and cannot function individually. Spore germination in C. sporogenes requires one tri-cistronic GR. Two other GRs form part of a complex involved in controlling the rate of amino-acid stimulated germination. The suitability of using C. sporogenes as a substitute for C. botulinum in germination studies and food challenge tests is discussed. Clostridium botulinum is a dangerous pathogen that forms the deadly botulinum neurotoxin. Strains of C. botulinum are present in the environment as spores. Under suitable conditions, the dormancy of the bacterial spore is broken, and germination occurs. Germination is initiated following the recognition of small molecules by a specific germinant receptor (GR) located within spores. Currently, the identification and characterisation of these GRs remains unknown, but is critical if strategies are to be developed to either prevent spore germination altogether, or to germinate all the spores and then inactivate the emergent sensitive vegetative cells. The present study has characterised two functionally active GRs in C. botulinum which act in synergy and cannot function individually, and a related functionally active GR in C. sporogenes. These GRs respond to amino acids. Other GRs appear to form part of a complex involved in controlling the speed of germination, or are not functionally active. This study provides new insights into the mechanisms involved in germination and will allow us to develop new strategies to control this deadly pathogen.
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影响因子：
4.4
作者：
Carter AT;Paul CJ;Mason DR;Twine SM;Alston MJ;Logan SM;Austin JW;Peck MW
通讯作者：
Peck MW
影响因子：
2.3
作者：
Broussolle, V;Alberto, F;Carlin, F
通讯作者：
Carlin, F
DOI：
10.1099/00207713-44-4-812
发表时间：
1994-10-01
期刊：
INTERNATIONAL JOURNAL OF SYSTEMATIC BACTERIOLOGY
影响因子：
--
作者：
COLLINS, MD;LAWSON, PA;FARROW, JAE
通讯作者：
FARROW, JAE
影响因子：
3.6
作者：
Griffiths KK;Zhang J;Cowan AE;Yu J;Setlow P
通讯作者：
Setlow P
影响因子：
2.4
作者：
Alberto, F;Broussolle, V;Peck, MW
通讯作者：
Peck, MW