Silverman D J, Wisseman C L, Waddell A
Infect Immun. 1980 Aug;29(2):778-90. doi: 10.1128/iai.29.2.778-790.1980.
Secondary chicken embryo fibroblasts infected in suspension with the Breinl strain of Rickettsia prowazekii and grown in monolayer culture were examined by both transmission and scanning electron microscopy at specific intervals after infection to study the effects of prolonged intracellular growth on the fine structure of the host cell and the rickettsiae. Cytopathological changes in the infected host cells were not apparent until late in the intracellular growth cycle when the cells began to rupture as a result of a large rickettsial burden. The only recognizable changes in heavily infected cells before lysis were the condensation of the intercristal matrix of some mitochondria and the apparent dissociation of ribosomes from the rough-surfaced endoplasmic reticulum. Although the effects of intracellular growth of rickettsiae on the fine structure of the host cell were rather unremarkable when compared with those imposed by Rickettsia rickettsii in a similar cell system, noticeable morphological changes in the rickettsiae were recognized during the intracellular growth cycle. These changes first became apparent about 40 h postinfection and consisted primarily of an increased electron density of the rickettsiae, the appearance of numerous vacuoles in the rickettsial cytoplasm, and a slight reduction in size of the rickettsiae. Changes of this nature may reflect transitional phases of growth characteristically seen in free-living bacterial cell systems.
用普氏立克次体的布赖恩尔菌株悬浮感染原代鸡胚成纤维细胞，并在单层培养中生长，在感染后的特定时间间隔通过透射电子显微镜和扫描电子显微镜进行检查，以研究细胞内长期生长对宿主细胞和立克次体精细结构的影响。在细胞内生长周期后期，当细胞因大量立克次体负荷而开始破裂时，感染的宿主细胞中的细胞病理学变化才明显。在裂解前，重度感染细胞中唯一可识别的变化是一些线粒体嵴间基质的浓缩以及核糖体与糙面内质网的明显解离。尽管与在类似细胞系统中立克次体感染所造成的影响相比，立克次体细胞内生长对宿主细胞精细结构的影响相当不显著，但在细胞内生长周期中，立克次体出现了明显的形态学变化。这些变化在感染后约40小时首次变得明显，主要包括立克次体电子密度增加、立克次体细胞质中出现大量空泡以及立克次体大小略有减小。这种性质的变化可能反映了在自由生活细菌细胞系统中典型出现的生长过渡阶段。
