Peavy C A, Lane R S, Kleinjan J E
Department of Environmental Science, Policy & Management University of California, Berkeley 94720, USA.
Exp Appl Acarol. 1997 Aug;21(8):569-84. doi: 10.1023/a:1018448416618.
The role of small mammals other than woodrats in the enzootiology of the Lyme disease spirochete, Borrelia burgorferi, was assessed in the peri-urban park. Mammals were collected monthly from September through to April. Following tick removal, the animals were tested for B. burgdorferi by culture of ear-punch biopsies. Larvae and nymphs that were intermediate in morphology between Ixodes spinipalpis and Ixodes neotomae occurred on several species of rodents (Peromyscus truei, Peromyscus californicus, Microtus californicus, Rattus rattus and Reithrodontomys megalotis) and the brush rabbit (Sylvilagus bachmani). Morphometric analyses of these I. spinipalpis-like ticks and the offspring from two I. neotomae females from the site suggest that I. neotomae may bo conspecific with I. spinipalpis. Borrelia burgdorferi was isolated from eight out of 109 (7.3%), three out of 16 (18.8%), two out of 38 (5.3%) and two out of six (33.3%) P. truei, P. maniculatus, M. californicus and R. rattus, respectively. One bush rabbit yielded the first isolate of B. burgdorferi from a lagomorph in western North America. This isolate and three others derived from unfed I. spinipalpis-like nymphs failed to produce infection when inoculated intradermally into 11-12 P. maniculatus each. Likewise, no spirochetes were detected in 420 Ixodes pacificus nymphs derived from larvae fed on animals inoculated with these isolates. An additional isolate, derived from an I. spinipalpis-like nymph, was recovered by ear-punch biopsies from five our of 12 (42%) needle-inoculated P. maniculatus. However, spirochetes were not detected in 20 I. pacificus nymphs fed as larvae on each of five mice (two infected and three uninfected) inoculated with this isolate. We conclude that brush rabbits and several species of rodents besides woodrats may contribute to the maintenance of B. burgdorferi because they harbour the spirochete and are fed upon by competent enzootic vectors.
在城市周边公园中，评估了林鼠之外的小型哺乳动物在莱姆病螺旋体——伯氏疏螺旋体动物流行病学中的作用。从9月至次年4月，每月收集哺乳动物。去除蜱虫后，通过耳打孔活检培养对动物进行伯氏疏螺旋体检测。在几种啮齿动物（特鲁伊白足鼠、加利福尼亚白足鼠、加利福尼亚田鼠、黑家鼠和大耳稻鼠）和灌丛兔（巴氏棉尾兔）身上发现了形态介于棘刺硬蜱和新域硬蜱之间的幼虫和若虫。对这些类似棘刺硬蜱的蜱虫以及该地点两只新域硬蜱雌虫的后代进行形态测量分析表明，新域硬蜱可能与棘刺硬蜱为同种。分别从109只特鲁伊白足鼠中的8只（7.3%）、16只白足鼠中的3只（18.8%）、38只加利福尼亚田鼠中的2只（5.3%）和6只黑家鼠中的2只（33.3%）中分离出伯氏疏螺旋体。一只灌丛兔产生了北美西部兔形目动物中首例伯氏疏螺旋体分离株。将该分离株及另外3株从未进食的类似棘刺硬蜱若虫中获得的分离株分别皮内接种到11 - 12只白足鼠体内后，均未引发感染。同样，在以接种了这些分离株的动物为食的幼虫发育而来的420只太平洋硬蜱若虫中未检测到螺旋体。从一只类似棘刺硬蜱的若虫中获得的另一个分离株，通过耳打孔活检从12只经针刺接种的白足鼠中的5只（42%）体内分离得到。然而，在以接种了该分离株的5只小鼠（2只感染，3只未感染）中的每只小鼠为食的幼虫发育而来的20只太平洋硬蜱若虫中未检测到螺旋体。我们得出结论，灌丛兔和除林鼠之外的几种啮齿动物可能有助于伯氏疏螺旋体的维持，因为它们携带该螺旋体并被有效的动物传播媒介叮咬。
