Stoffel Ryan T, McClure Jennifer C, Butcher Marion M, Johnson Gayle C, Roland Will, Cheng Chuanmin, Sirigireddy Kamesh R, Ganta Roman, Boughan Kirstin, Ewing S A, Stich Roger W
Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA.
Department of Internal Medicine Infectious Disease Division, University of Missouri, Columbia, MO 65211, USA.
Vet Microbiol. 2014 Aug 6;172(1-2):334-8. doi: 10.1016/j.vetmic.2014.04.017. Epub 2014 May 4.
Ehrlichia chaffeensis, the etiologic agent of human monocytic ehrlichiosis, is a tick-borne rickettsial pathogen that is infective to a wide range of mammals, including dogs and people. Amblyomma americanum, the lone star tick, is considered the primary vector of E. chaffeensis, but this pathogen has been detected in other tick species, including the brown dog tick, Rhipicephalus sanguineus. We hypothesized that the Arkansas strain of E. chaffeensis is infective to R. sanguineus, and used a novel PCR assay to test for acquisition of this pathogen by R. sanguineus and A. americanum ticks that were simultaneously fed on experimentally infected dogs. Although E. chaffeensis was not frequently detected in peripheral blood of these dogs, the pathogen was detected in both tick species and in canine lung, kidney, lymph node, bone marrow and frontal lobe samples. One dog (AFL) was maintained for several years, and ticks again acquired E. chaffeensis from this dog 566 days after intradermal inoculation with E. chaffeensis, but the pathogen was not detected in ticks fed on the same dog at 764 or 1086 days after the intradermal inoculation.
查菲埃立克体是人类单核细胞埃立克体病的病原体，是一种通过蜱传播的立克次氏体病原体，可感染包括狗和人类在内的多种哺乳动物。美洲钝眼蜱是查菲埃立克体的主要传播媒介，但在其他蜱种中也检测到了这种病原体，包括棕狗蜱血红扇头蜱。我们推测查菲埃立克体的阿肯色菌株可感染血红扇头蜱，并使用一种新型聚合酶链反应（PCR）检测方法，来检测同时吸食实验感染犬血液的血红扇头蜱和美洲钝眼蜱是否感染了这种病原体。尽管在这些犬的外周血中不常检测到查菲埃立克体，但在这两种蜱以及犬的肺、肾、淋巴结、骨髓和额叶样本中均检测到了该病原体。一只犬（AFL）被饲养了数年，在皮内接种查菲埃立克体566天后蜱再次从这只犬身上感染了查菲埃立克体，但在皮内接种764天或1086天后吸食同一只犬血液的蜱中未检测到该病原体。
