Perrett Charlotte A, Jepson Mark A
Department of Biochemistry, School of Medical Sciences, University of Bristol, United Kingdom.
Methods Mol Biol. 2007;394:235-73. doi: 10.1007/978-1-59745-512-1_12.
Salmonella enterica is a Gram-negative enteropathogen that can cause localized infections, typically resulting in gastroenteritis, or systemic infection, e.g., typhoid fever, in both humans and warm-blooded animals. Understanding the mechanisms by which Salmonella induce disease has been the focus of intensive research. This has revealed that Salmonella invasion requires dynamic cross-talk between the microbe and host cells, in which bacterial adherence rapidly leads to a complex sequence of cellular responses initiated by proteins translocated into the host cell by a type III secretion system (T3SS). Once these Salmonella-induced responses have resulted in bacterial invasion, proteins translocated by a second T3SS initiate further modulation of cellular activities to enable survival and replication of the invading pathogen. These processes contribute to Salmonella entry into the host and the clinical symptoms of gastrointestinal and systemic infection. Elucidation of the complex and highly dynamic pathogen-host interactions ultimately requires analysis at the level of single cells and single infection events. To achieve this goal, researchers have applied a diverse range of microscopical methods to examine Salmonella infection in models ranging from whole animal to isolated cells and simple eukaryotic organisms. For example, electron microscopy and confocal microscopy can reveal the juxtaposition of Salmonella, its products, and cellular components at high resolution. Simple light microscopy (LM) can also be used to investigate the interaction of bacteria with host cells and has advantages for live cell imaging, which enables detailed analysis of the dynamics of infection and cellular responses. Here we review the use of imaging techniques in Salmonella research and compare the capabilities of different classes of microscope to address specific types of research question. We also provide protocols and notes on several LM techniques routinely used in our own research.
肠炎沙门氏菌是一种革兰氏阴性肠道病原体，可在人类和温血动物中引起局部感染，通常导致肠胃炎，或引起全身感染，如伤寒热。了解沙门氏菌引发疾病的机制一直是深入研究的重点。研究表明，沙门氏菌的入侵需要微生物与宿主细胞之间进行动态的相互作用，其中细菌的黏附会迅速引发一系列复杂的细胞反应，这些反应由通过III型分泌系统（T3SS）转运到宿主细胞中的蛋白质启动。一旦这些由沙门氏菌引发的反应导致细菌入侵，由第二个T3SS转运的蛋白质会进一步调节细胞活动，以使入侵病原体能够存活和复制。这些过程有助于沙门氏菌进入宿主以及引发胃肠道和全身感染的临床症状。阐明复杂且高度动态的病原体 - 宿主相互作用最终需要在单细胞和单个感染事件层面进行分析。为实现这一目标，研究人员应用了多种显微镜方法来检查从全动物到分离细胞以及简单真核生物模型中的沙门氏菌感染情况。例如，电子显微镜和共聚焦显微镜可以高分辨率揭示沙门氏菌及其产物与细胞成分的并置情况。简单的光学显微镜（LM）也可用于研究细菌与宿主细胞的相互作用，并且在活细胞成像方面具有优势，能够详细分析感染动态和细胞反应。在这里，我们回顾成像技术在沙门氏菌研究中的应用，并比较不同类型显微镜解决特定研究问题的能力。我们还提供了一些我们自己研究中常规使用的LM技术的方案和注意事项。
