Abteilung Mikrobiologie, CellNanOs - Center of Cellular Nanoanalytics Osnabrück, Universität Osnabrück, Osnabrück, Germany.
Cell Microbiol. 2021 Mar;23(3):e13293. doi: 10.1111/cmi.13293. Epub 2020 Dec 17.
Intracellular bacteria such as Salmonella enterica are confronted with a broad array of defence mechanisms of their mammalian host cells. The ability to sense host cell-imposed damages, and to mount efficient stress responses are crucial for survival and proliferation of intracellular pathogens. The various combinations of host defence mechanisms acting on intracellular bacteria and their individual response also explain the occurrence of distinct subpopulations of intracellular S. enterica such as dormant or persisting, slowly or rapidly replicating cells. Here we describe a set of fluorescence protein (FP)-based reporter strains that were used to monitor the expression of cytoplasmic or periplasmic stress response systems of single bacterial cells. This is mediated by a fast-maturing FP as reporter for induction of stress response genes. We evaluated slower maturing FPs for a second function, that is, the analysis of the status of intracellular proliferation of pathogens. The combination of two FPs allows, at level of single bacterial cells, the interrogation of stress response and intracellular proliferation. Application of these reporters to S. enterica allowed us to detect and quantify distinct intracellular subpopulations with different levels of stress response and proliferation.
细胞内细菌，如沙门氏菌，会面临其哺乳动物宿主细胞的广泛防御机制。感知宿主细胞施加的损伤，并对其作出有效的应激反应的能力，对细胞内病原体的存活和增殖至关重要。作用于细胞内细菌的各种宿主防御机制的组合及其各自的反应，也解释了细胞内沙门氏菌的不同亚群的发生，如休眠或持续存在、缓慢或快速复制的细胞。在这里，我们描述了一组荧光蛋白（FP）报告菌株，用于监测单个细菌细胞中细胞质或周质应激反应系统的表达。这是通过快速成熟的 FP 作为诱导应激反应基因表达的报告来实现的。我们评估了较慢成熟的 FP 来实现第二个功能，即分析病原体的细胞内增殖状态。两个 FP 的组合允许在单个细菌细胞水平上，对应激反应和细胞内增殖进行检测。将这些报告基因应用于沙门氏菌，使我们能够检测和定量不同应激反应和增殖水平的不同细胞内亚群。
