Institut Pasteur, Biologie des Bactéries Intracellulaires, Paris, France.
Centre National de la Recherche Scientifique, UMR 3525, Paris, France.
Front Cell Infect Microbiol. 2018 Jan 19;8:3. doi: 10.3389/fcimb.2018.00003. eCollection 2018.
is a gram-negative bacterium that inhabits freshwater ecosystems, where it is present in biofilm or as planktonic form. is mainly found associated with protozoa, which serve as protection from hostile environments and as replication niche. If inhaled within aerosols, is also able to infect and replicate in human alveolar macrophages, eventually causing the Legionnaires' disease. The transition between intracellular and extracellular environments triggers a differentiation program in which metabolic as well as morphogenetic changes occur. We here describe the current knowledge on how the different developmental states of this bacterium are regulated, with a particular emphasis on the stringent response activated during the transition from the replicative phase to the infectious phase and the metabolic features going in hand. We propose that the cellular differentiation of this intracellular pathogen is closely associated to key metabolic changes in the bacterium and the host cell, which together have a crucial role in the regulation of virulence.
是一种革兰氏阴性菌，栖息在淡水生态系统中，以生物膜或浮游形式存在。 主要与原生动物有关，原生动物为其提供了免受恶劣环境侵害和复制栖身之所的保护。如果以气溶胶的形式吸入， 也能够感染并在人类肺泡巨噬细胞中复制，最终导致军团病。从细胞内到细胞外环境的转变触发了一个分化程序，其中发生代谢和形态发生的变化。在这里，我们描述了目前对这种细菌的不同发育状态是如何被调控的认识，特别强调了在从复制阶段到感染阶段的转变过程中被激活的严格反应以及随之发生的代谢特征。我们提出，这种细胞内病原体的细胞分化与细菌和宿主细胞中的关键代谢变化密切相关，这些变化共同在调节 毒力方面起着至关重要的作用。
