Stromdahl E Y, Randolph M P, O'Brien J J, Gutierrez A G
Entomological Sciences Program, U.S. Army Center for Health Promotion and Preventive Medicine, Aberdeen Proving Ground, MD 21010-5403, USA.
J Med Entomol. 2000 May;37(3):349-56. doi: 10.1093/jmedent/37.3.349.
Human monocytic ehrlichiosis (HME) is a sometimes fatal, emerging tick-borne disease caused by the bacterium Ehrlichia chaffeensis. It is frequently misdiagnosed because its symptoms mimic those of the flu. Current evidence indicates that Amblyomma americanum (L.), the lone star tick, is the major vector of HME. To determine if E. chaffeensis is present in ticks at Aberdeen Proving Ground, MD, questing A. americanum ticks were collected from 33 sites. Nucleic acid was extracted from 34 adult and 81 nymphal pools. Sequences diagnostic for E. chaffeensis from three different loci (16S rRNA, 120-kDa protein, and a variable-length polymerase chain reaction [PCR] target, or VLPT) were targeted for amplification by the PCR. Fifty-two percent of the collection sites yielded pools infected with E. chaffeensis, confirming the presence and widespread distribution of E. chaffeensis at Aberdeen Proving Ground. Analysis with the both the 120-kDa protein primers and the VLPT primers showed that genetic variance exists. A novel combination of variance for the two loci was detected in two tick pools. The pathogenic implications of genetic variation in E. chaffeensis are as yet unknown.
人单核细胞埃立克体病（HME）是一种由恰菲埃立克体引起的、有时会致命的新发蜱传疾病。该病常被误诊，因为其症状与流感相似。目前的证据表明，美洲钝眼蜱是HME的主要传播媒介。为了确定马里兰州阿伯丁试验场的蜱中是否存在恰菲埃立克体，从33个地点采集了正在 questing 的美洲钝眼蜱。从34个成虫样本库和81个若虫样本库中提取了核酸。通过聚合酶链反应（PCR）扩增来自三个不同基因座（16S rRNA、120 kDa蛋白和可变长度聚合酶链反应[PCR]靶标，即VLPT）的恰菲埃立克体诊断序列。52%的采集地点的样本库检测出感染了恰菲埃立克体，证实了阿伯丁试验场存在恰菲埃立克体且分布广泛。用120 kDa蛋白引物和VLPT引物进行分析表明存在遗传变异。在两个蜱样本库中检测到两个基因座变异的一种新组合。恰菲埃立克体遗传变异的致病意义尚不清楚。
原文中“questing”可能有误，推测可能是“questing”（搜索、探寻）的拼写错误，这里暂按此翻译，你可根据实际情况调整。
