Brandsma A R, Little S E, Lockhart J M, Davidson W R, Stallknecht D E, Dawson J E
Department of Medical Microbiology and Parasitology, College of Veterinary Medicine, University of Georgia, Athens 30602, USA.
J Med Entomol. 1999 Mar;36(2):190-4. doi: 10.1093/jmedent/36.2.190.
Polymerase chain reaction (PCR) evidence of a novel Ehrlichia organism was found recently in wild white-tailed deer, Odocoileus virginianus Zimmermann, and lone star ticks, Amblyomma americanum L., from the southeastern United States. To evaluate whether lone star tick parasitism was associated with the presence of this novel Ehrlichia organism in deer, 2 retrospective studies were conducted using specific nested PCR to test archived deer serum samples. The 1st study of 150 serum samples collected from a single deer population over a 15-yr period examined the temporal association between the presence of the Ehrlichia organism in deer and parasitism by lone star ticks. The deer Ehrlichia was not detected in serum samples collected before 1986, when lone star ticks were absent or rare, but was detected in samples collected in 1986 and every year thereafter, when lone star ticks became increasingly abundant. In the 2nd study, serum samples from 120 deer from 24 sites in 14 southeastern states were tested to evaluate if a site-specific, spatial association existed between the presence of the deer Ehrlichia and lone star ticks. All 60 serum samples from the 12 deer populations without evidence of lone star tick infestation were negative for the deer Ehrlichia, whereas 83% of the 12 populations infested by lone star ticks had PCR evidence of infection. These data suggest that lone star ticks may be a vector of the deer Ehrlichia; however, they do not preclude the involvement of other arthropods in maintaining infection with this organism in deer populations.
最近在美国东南部的野生白尾鹿（Odocoileus virginianus Zimmermann）和孤星蜱（Amblyomma americanum L.）中发现了一种新型埃立克体生物的聚合酶链反应（PCR）证据。为了评估孤星蜱寄生是否与鹿体内这种新型埃立克体生物的存在有关，进行了两项回顾性研究，使用特异性巢式PCR检测存档的鹿血清样本。第一项研究对15年间从单一鹿群中采集的150份血清样本进行了检测，研究鹿体内埃立克体生物的存在与孤星蜱寄生之间的时间关联。在1986年之前采集的血清样本中未检测到鹿埃立克体，当时孤星蜱不存在或很稀少，但在1986年及之后每年采集的样本中都检测到了，此时孤星蜱数量日益增多。在第二项研究中，对来自东南部14个州24个地点的120只鹿的血清样本进行了检测，以评估鹿埃立克体的存在与孤星蜱之间是否存在特定地点的空间关联。来自12个没有孤星蜱感染迹象的鹿群的所有60份血清样本对鹿埃立克体呈阴性，而在12个受到孤星蜱感染的鹿群中，83%有PCR感染证据。这些数据表明孤星蜱可能是鹿埃立克体的传播媒介；然而，它们并不排除其他节肢动物在鹿群中维持这种生物感染方面的作用。
