Institut Pasteur, Biologie des Bactéries Intracellulaires and CNRS UMR 3525, 75724 Paris, France.
Cold Spring Harb Perspect Med. 2013 Jun 1;3(6):a009993. doi: 10.1101/cshperspect.a009993.
Legionella pneumophila is a bacterial pathogen present in aquatic environments that can cause a severe pneumonia called Legionnaires' disease. Soon after its recognition, it was shown that Legionella replicates inside amoeba, suggesting that bacteria replicating in environmental protozoa are able to exploit conserved signaling pathways in human phagocytic cells. Comparative, evolutionary, and functional genomics suggests that the Legionella-amoeba interaction has shaped this pathogen more than previously thought. A complex evolutionary scenario involving mobile genetic elements, type IV secretion systems, and horizontal gene transfer among Legionella, amoeba, and other organisms seems to take place. This long-lasting coevolution led to the development of very sophisticated virulence strategies and a high level of temporal and spatial fine-tuning of bacteria host-cell interactions. We will discuss current knowledge of the evolution of virulence of Legionella from a genomics perspective and propose our vision of the emergence of this human pathogen from the environment.
嗜肺军团菌是一种存在于水生环境中的细菌病原体，可引起一种称为军团病的严重肺炎。在其被发现后不久，研究表明军团菌在变形虫内复制，这表明在环境原生动物中复制的细菌能够利用人类吞噬细胞中的保守信号通路。比较、进化和功能基因组学表明，军团菌-变形虫的相互作用比以前认为的更能塑造这种病原体。一种涉及移动遗传元件、IV 型分泌系统以及军团菌、变形虫和其他生物体之间的水平基因转移的复杂进化场景似乎正在发生。这种持久的共同进化导致了非常复杂的毒力策略的发展，并对细菌与宿主细胞的相互作用进行了高度的时间和空间微调。我们将从基因组学的角度讨论嗜肺军团菌毒力进化的现有知识，并提出我们对这种人类病原体从环境中出现的看法。
