Characterization of a new isolate of Ehrlichia platys (Order Rickettsiales) using electron microscopy and polymerase chain reaction
Characterization of a new isolate of Ehrlichia platys (Order Rickettsiales) using electron microscopy and polymerase chain reaction
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DOI：
10.1016/s0304-4017(96)01052-7
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发表时间：
1997-01-01
影响因子：
2.6
通讯作者：
Fox, JC
中科院分区：
文献类型：
--
作者：
Mathew, JS;Ewing, SA;Fox, JC
俄克拉荷马州立大学实验动物资源中心在俄克拉荷马州中北部获得了一只约 3 个月大的混种幼犬，其表现出血小板内含物。出现内含物后，狗出现严重血小板减少症（<10 000 μl(-1)）。每天监测血片，当约 75% 的血小板有内含物时，在 EDTA 中收集样本并进行处理以用于电子显微镜 (EM) 研究和聚合酶链反应 (PCR)。对戊二醛固定的血沉棕黄层的电镜研究揭示了许多血小板中存在立克次体样内含物。使用普拉提埃里希体抗原进行的血清学检查显示，滴度较高，提示存在普拉提埃里希体感染。源自 E. platys 16S rRNA 基因序列高度可变区域的 PCR 引物被用来特异性扩增寄生虫 DNA 的该区域。通过通用埃里希体引物获得的 PCR 产物的测序显示，与已发表的艾里希体序列有一个核苷酸差异，这表明这种细胞内寄生虫可能存在菌株变异。我们的结果表明，PCR 可能是诊断白喉埃里希体感染的有用工具，并且与其他埃里希体属一样，白喉埃里希体分离株可能有所不同。
A mixed-breed pup approximately 3 months old obtained in north central Oklahoma by the Laboratory Animal Resources Unit of Oklahoma State University presented with platelet inclusions. The dog developed severe thrombocytopenia (< 10 000 mu l(-1)) following the appearance of inclusions. Blood films were monitored daily and when about 75% of platelets had inclusions, samples were collected in EDTA and processed for electron microscopic (EM) studies and polymerase chain reaction (PCR). EM studies on glutaraldehyde-fixed buffy coat revealed rickettsia-like inclusions in numerous platelets. Serologic examination, using Ehrlichia platys antigen, showed high titre suggestive of E. platys infection. PCR primers derived from a highly variable region of the 16S rRNA gene sequence of E. platys were used to specifically amplify that region of the parasite's DNA. Sequencing of the PCR product obtained by general Ehrlichia primers showed one nucleotide difference from the published sequence for E. platys which suggests possible strain variation of this intracellular parasite. Our results indicate that PCR may be a useful tool in the diagnosis of E. platys infection and that, like other Ehrlichia spp., E. platys isolates may vary.