Hodzic E, Borjesson D L, Feng S, Barthold S W
Center for Comparative Medicine, School of Medicine, University of California Davis, 95616, USA.
Vector Borne Zoonotic Dis. 2001 Summer;1(2):149-58. doi: 10.1089/153036601316977750.
The population dynamics of two cotransmitted tick-borne pathogens, Borrelia burgdorferi and the agent of human granulocytic ehrlichiosis (aoHGE), were assessed at the skin-vector interface at intervals after tick attachment on infected mice. Quantitative real-time polymerase chain reaction targeting the B. burgdorferi flagellin gene revealed consistent decreases in spirochete numbers in skin at the sites of tick attachment compared with non-tick attachment sites. This phenomenon was found during early (2 weeks) and late (8 weeks) infection and at 24, 48, and 72 h after tick attachment. A nonspecific inflammatory stimulus, implantation of suture material, did not have this effect. In contrast to B. burgdorferi, copy numbers of an aoHGE p44 target gene target were significantly increased at the sites of tick attachment, compared with non-tick sites. The non-specific stimulus of suture material had the same effect on aoHGE recruitment as tick attachment in aoHGE infected mice. These results reinforce the concept that B. burgdorferi interfaces with its vector by virtue of its non-systemic dermatotropism, and not via systemic hematogenous acquisition. In contrast, results indicate that the aoHGE relies upon hematogenous acquisition. Thus, these two cotransmitted tick-borne pathogens utilize distinctly different means of vector acquisition.
在感染小鼠身上蜱虫附着后的不同时间间隔，对两种共同传播的蜱传病原体——伯氏疏螺旋体和人粒细胞埃立克体病病原体（aoHGE）在皮肤-媒介界面处的种群动态进行了评估。针对伯氏疏螺旋体鞭毛蛋白基因的定量实时聚合酶链反应显示，与非蜱虫附着部位相比，蜱虫附着部位皮肤中的螺旋体数量持续减少。在感染早期（2周）和晚期（8周）以及蜱虫附着后24、48和72小时均发现了这种现象。一种非特异性炎症刺激，即缝合材料植入，并未产生这种效果。与伯氏疏螺旋体相反，与非蜱虫附着部位相比，aoHGE p44靶基因的拷贝数在蜱虫附着部位显著增加。在感染aoHGE的小鼠中，缝合材料的非特异性刺激对aoHGE募集的影响与蜱虫附着相同。这些结果强化了这样一个概念，即伯氏疏螺旋体凭借其非全身性皮肤嗜性而非通过全身性血行获取与媒介相互作用。相比之下，结果表明aoHGE依赖血行获取。因此，这两种共同传播的蜱传病原体利用截然不同的方式获取媒介。
