Peavey C A, Lane R S
Department of Environmental Science, Policy and Management, University of California, Berkeley 94720, USA.
J Parasitol. 1995 Apr;81(2):175-8.
The transmission of Borrelia burgdorferi to deer mice (Peromyscus maniculatus) by Ixodes pacificus nymphs was investigated experimentally. Deer mice were exposed to infected nymphs for 24, 48, or 72 hr, or until ticks had fed to repletion (> or = 96 hr). Infection status of hosts was assessed 4 wk later by culture of ear-punch biopsies in BSK II medium and by indirect immunofluorescence. Eight mice exposed to ticks for 24 hr did not become Infected. In contrast, infection was acquired by 1 of 9 (11%), 2 of 8 (25%), and 8 of 10 (80%) mice exposed for 48, 72, and > or = 96 hr, respectively. Eight weeks after exposure to infected nymphs, the infectivity of 5 deer mice for I. pacificus larvae was assessed. Overall, 33% of I. pacificus larvae fed on these mice acquired and transstadially passed spirochetes. We conclude that most I. pacificus nymphs require 4 days or longer to transmit spirochetes to deer mice, and that larvae efficiently acquire and maintain spirochetes from mice that have been infected by tick-bite.
通过实验研究了太平洋硬蜱若虫将伯氏疏螺旋体传播给鹿鼠（白足鼠）的情况。将鹿鼠暴露于感染的若虫24、48或72小时，或直到蜱虫饱食（≥96小时）。4周后，通过在BSK II培养基中培养耳打孔活检组织并进行间接免疫荧光来评估宿主的感染状况。8只暴露于蜱虫24小时的小鼠未被感染。相比之下，分别暴露48、72和≥96小时的9只小鼠中有1只（11%）、8只小鼠中有2只（25%）以及10只小鼠中有8只（80%）被感染。在暴露于感染若虫8周后，评估了5只鹿鼠对太平洋硬蜱幼虫的感染性。总体而言，以这些小鼠为食的太平洋硬蜱幼虫中有33%获得并经变态传递了螺旋体。我们得出结论，大多数太平洋硬蜱若虫需要4天或更长时间才能将螺旋体传播给鹿鼠，并且幼虫能有效地从被蜱叮咬感染的小鼠中获得并维持螺旋体。
