Kocan K M, Crawford T B, Dilbeck P M, Evermann J F, McGuire T C
Department of Veterinary Pathology, College of Veterinary Medicine, Stillwater 74078.
J Bacteriol. 1990 Oct;172(10):5949-55. doi: 10.1128/jb.172.10.5949-5955.1990.
An obligate intracellular rickettsial organism isolated from an aborted bovine fetus was studied in bovine turbinate and mouse macrophage cell cultures with light and electron microscopy. Development of the organism was similar in both cell types. The organism replicated within cytoplasmic vacuoles in a developmental cycle that resembled that of both the ehrlichiae and chlamydiae. The inoculum contained only electron-dense forms, which infected cells within 2 h postinoculation by adhering to cell membranes at thickened areas that appeared to be coated pits and then being endocytosed. A striking feature occurred next as the organisms became surrounded by host cell mitochondria and, by light microscopy, appeared to have halos. During this intimate association with mitochondria, the electron-dense organisms changed into large reticulated forms that began to divide by binary fission. These large forms were often in direct contact with mitochondrial membranes. The organisms continued to divide by binary fission, and host cells contained large cytoplasmic inclusions of reticulated organisms. The reticulated organisms gradually changed into electron-dense forms that were released from degenerated host cells.
从一头流产的牛胎儿中分离出一种专性细胞内立克次氏体微生物，利用光学显微镜和电子显微镜在牛鼻甲和小鼠巨噬细胞培养物中对其进行了研究。该微生物在两种细胞类型中的发育情况相似。该微生物在细胞质空泡内复制，其发育周期类似于埃立克体和衣原体的发育周期。接种物仅包含电子致密形态，接种后2小时内，它们通过粘附在似乎是被膜小窝的增厚区域的细胞膜上，然后被内吞，从而感染细胞。接下来出现了一个显著特征，即这些微生物被宿主细胞线粒体包围，在光学显微镜下似乎有光晕。在与线粒体的这种紧密关联过程中，电子致密的微生物转变为大型网状形态，并开始通过二分裂进行分裂。这些大型形态通常与线粒体膜直接接触。微生物继续通过二分裂进行分裂，宿主细胞含有大型的网状微生物细胞质内含物。网状微生物逐渐转变为电子致密形态，并从退化的宿主细胞中释放出来。
