Ultrastructural study of ehrlichial organisms in the large colons of ponies infected with Potomac horse fever
Ultrastructural study of ehrlichial organisms in the large colons of ponies infected with Potomac horse fever
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感染波托马克马热的小马大结肠中埃利希体微生物的超微结构研究
DOI：
10.1128/iai.49.3.505-512.1985
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发表时间：
1985
影响因子：
3.1
通讯作者：
D. Cordes
中科院分区：
文献类型：
--
作者：
Y. Rikihisa;B. Perry;D. Cordes
波托马克马热的特点是发烧、厌食、白细胞减少、大量水样腹泻、脱水和高死亡率。研究人员对小马的消化系统、淋巴器官和血细胞进行了超微结构检查，以寻找在输入自然感染波托马克马热病的马的全血后出现临床症状的小马的消化系统、淋巴器官和血细胞中是否存在异常微生物。一致的发现是这些小马的肠道壁中存在立克次体微生物。微生物主要存在于大结肠壁，小结肠、空肠和盲肠中微生物较少。在培养的血液单核细胞中也检测到了这种生物体。在肠壁中，许多微生物存在于深部腺上皮细胞和肥大细胞的胞浆内。在固有层和粘膜下层的腺上皮细胞之间迁移的巨噬细胞中也发现了微生物。这些微生物是圆形的，非常多形性，并且被宿主膜包围。它们含有细链 DNA 和核糖体，并被双叶膜包围。它们的超微结构与立克次体科埃立克体属的超微结构非常相似。在肠道壁（尤其是大结肠）中频繁检测到该生物体，表明该生物体中存在器官营养性。受感染的血液单核细胞可能是器官之间和动物之间传播的载体。特征性的严重腹泻可能是由生物体直接通过损害上皮细胞功能引起的，或者是通过干扰肠壁中受感染的巨噬细胞和肥大细胞间接引起的，或者两者兼而有之。
Potomac horse fever is characterized by fever, anorexia, leukopenia, profuse watery diarrhea, dehydration, and high mortality. An ultrastructural investigation was made to search for any unusual microorganisms in the digestive system, lymphatic organs, and blood cells of ponies that had developed clinical signs after transfusion with whole blood from horses naturally infected with Potomac horse fever. A consistent finding was the presence of rickettsial organisms in the wall of the intestinal tract of these ponies. The organisms were found mostly in the wall of the large colon, but fewer organisms were found in the small colon, jejunum, and cecum. The organisms were also detected in cultured blood monocytes. In the intestinal wall, many microorganisms were intracytoplasmic in deep glandular epithelial cells and mast cells. Microorganisms were also found in macrophages migrating between glandular epithelial cells in the lamina propria and submucosa. The microorganisms were round, very pleomorphic, and surrounded by a host membrane. They contained fine strands of DNA and ribosomes and were surrounded by double bileaflet membranes. Their ultrastructure was very similar to that of the genus Ehrlichia, a member of the family Rickettsiaceae. The high frequency of detection of the organism in the wall of the intestinal tract, especially in the large colon, indicates the presence of organotrophism in this organism. Infected blood monocytes may be the vehicle for transmission between organs and between animals. The characteristic severe diarrhea may be induced by the organism directly by impairing epithelial cell functions or indirectly by perturbing infected macrophages and mast cells in the intestinal wall or by both.