Direct cultivation of the causative agent of human granulocytic ehrlichiosis
Direct cultivation of the causative agent of human granulocytic ehrlichiosis
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DOI：
10.1056/nejm199601253340401
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发表时间：
1996-01-25
影响因子：
158.5
通讯作者：
Munderloh, UG
中科院分区：
文献类型：
--
作者：
Goodman, JL;Nelson, C;Munderloh, UG
背景人粒细胞埃立克体病是一种潜在的致命蜱传感染，最近被描述，这种急性发热性疾病的特征是肌痛，头痛，血小板减少和血清转氨酶水平升高，该疾病难以诊断，因为症状是非特异性的，白细胞内包涵体（桑椹胚）可能看不到，并且血清学结果通常最初为阴性，由于从未培育过这种病原体，因此人们对它知之甚少。方法。我们研究了三名患者的症状和实验室检查结果提示人类粒细胞埃立克体病，包括不明原因的发热后，可能暴露于蜱，粒细胞减少症，血小板减少症。用显微镜和聚合酶链反应（PCR）检测外周血中埃立克体的感染情况，并将血液接种于HL 60细胞（人早幼粒细胞白血病细胞系）培养物中，用Giemsa染色和PCR检测感染情况。来自三名患者的血液（其中只有一名患者具有提示嗜中性粒细胞中埃里希体的内含物）在PCR上对人粒细胞埃里希体病呈阳性。将来自所有三名患者的血液接种到HL 60细胞培养物中并引起感染，早在接种后5天就可观察到细胞内生物体，并且在12至14天内发生细胞溶解。通过免疫荧光显微镜、PCR分析和DNA测序确认培养生物体的身份，在16S核糖体基因的区域中对来自感染细胞的DNA进行测序，所述16S核糖体基因的区域被报道为在人粒细胞埃立克体病的病原体和密切相关的物种之间存在差异，包括马埃立克体和马埃立克体。嗜吞噬细胞菌，导致动物感染。所有三种人类分离株的序列均相同，但与大肠杆菌菌株不同。马的第84位核苷酸是鸟嘌呤而不是腺嘌呤。我们描述了在细胞培养中培养人粒细胞埃立克体病的病原体，分离这种微生物的能力应有助于更好地了解这种新出现的感染的生物学、治疗和流行病学。(C)1996年，马萨诸塞州医学会。
Background. Human granulocytic ehrlichiosis is a potentially fatal tick-borne infection that has recently been described, This acute febrile illness is characterized by myalgias, headache, thrombocytopenia, and elevated serum aminotransferase levels, The disease is difficult to diagnose because the symptoms are nonspecific, intraleukocytic inclusions (morulae) may not be seen, and the serologic results are often initially negative, Little is known about the causative agent because it has never been cultivated.Methods. We studied three patients with symptoms and laboratory findings suggestive of human granulocytic ehrlichiosis, including unexplained fever after probable exposure to ticks, granulocytopenia, and thrombocytopenia. Peripheral blood was examined for ehrlichia microscopically and with use of the polymerase chain reaction (PCR), Blood was inoculated into cultures of HL60 cells (a line of human promyelocytic leukemia cells), and the cultures were monitored for infection by Giemsa staining and PCR.Results. Blood from the three patients, only one of whom had inclusions suggestive of ehrlichia in neutrophils, was positive for human granulocytic ehrlichiosis on PCR, Blood from all three patients was inoculated into HL60 cell cultures and caused infection, with intracellular organisms visualized as early as 5 days after inoculation and cell lysis occurring within 12 to 14 days, The identity of the cultured organisms was confirmed by immunofluorescence microscopy, PCR analysis, and DNA sequencing, DNA from the infected cells was sequenced in regions of the 16S ribosomal gene reported to differ between the agent of human granulocytic ehrlichiosis and closely related species, including Ehrlichia equi and E. phagocytophila, which cause infection in animals. The sequences from all three human isolates were identical and differed from the strain of E. equi studied in having guanine rather than adenine at nucleotide 84.Conclusions. We describe the cultivation of the agent of human granulocytic ehrlichiosis in cell culture, The ability to isolate this organism should lead to a better understanding of the biology, treatment, and epidemiology of this emerging infection. (C) 1996, Massachusetts Medical Society.