CEMOVIS on a pathogen: analysis of Bacillus anthracis spores
CEMOVIS on a pathogen: analysis of Bacillus anthracis spores
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DOI：
10.1042/bc20100080
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发表时间：
2010-11-01
影响因子：
2.7
通讯作者：
Sachse, Martin
中科院分区：
文献类型：
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作者：
Couture-Tosi, Evelyne;Ranck, Jean-Luc;Sachse, Martin
背景资料在饥饿的条件下，芽孢杆菌能够形成高度结构化的细胞类型，即休眠孢子。当环境呈现出更有利的条件时，孢子开始萌发，这将导致在生命周期中释放营养体，芽孢杆菌对于炭疽杆菌，炭疽的病原体，萌发通常与宿主的吸收有关，是炭疽病发病的重要步骤。结果和结论在本研究中，我们使用CEMOVIS描述了休眠孢子的形态，（玻璃体切片的冷冻电子显微镜检查）生物安全措施不允许冷冻未经化学固定的天然B炭疽孢子为了研究醛固定对孢子超微结构的影响，我们选择分析密切相关的非病原体蜡状芽孢杆菌T的孢子。由于所研究的结构与CEMOVIS的天然制备物相比，我们没有发现醛固定诱导的形态学差异。该结果证明了使用CEMOVIS对来自B炭疽菌的固定化孢子进行的工作是合理的，我们描述了芽孢中存在的两种新结构，一种是连接BcIA细丝与外孢壁基底层的矩形结构，另一种是在外被的末端层发现的重复结构。我们研究了芽孢杆菌在萌发过程中的形态变化。被毛和孢子外壁保持联系，被毛的分层结构以及其中的重复结构保持不变
Background information Under conditions of starvation, bacteria of Bacillus ssp are able to form a highly structured cell type, the dormant spore When the environment presents more favourable conditions, the spore starts to germinate, which will lead to the release of the vegetative form in the life cycle, the bacillus For Bacillus anthracis, the aetiological agent of anthrax, germination is normally linked to host uptake and represents an important step in the onset of anthrax disease Morphological studies analysing the organization of the spore and the changes during germination at the electron microscopy level were only previously performed with techniques relying on fixation with aldehydes and osmium, and subsequent dehydration, which can produce artefactsResults and conclusions In the present study, we describe the morphology of dormant spores using CEMOVIS (Cryo-Electron Microscopy of Vitreous Sections) Biosafety measures do not permit freezing of native spores of B anthracis without chemical fixation To study the influence of aldehyde fixation on the ultrastructure of the spore, we chose to analyse spores of the closely related non-pathogen Bacillus cereus T For none of the investigated structures could we find a difference in morphology induced by aldehyde fixation compared with the native preparations for CEMOVIS This result legitimizes work with aldehyde-fixed spores from B anthracis Using CEMOVIS, we describe two new structures present in the spore a rectangular structure, which connects the BcIA filaments with the basal layer of the exosporium, and a repetitive structure, which can be found in the terminal layer of the coat We studied the morphological changes of the spore during germination After outgrowth of the bacillus, coat and exosporium stay associated, and the layered organization of the coat, as well as the repetitive structure within it, remain unchanged