Laboratory of Zoonotic Pathogens, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana 59840, USA.
J Med Entomol. 2011 Jul;48(4):891-5. doi: 10.1603/me10283.
Tick-borne relapsing fever is caused by spirochetes within the genus Borrelia. The hallmark of this disease is recurrent febrile episodes and high spirochete densities in mammalian blood resulting from immune evasion. Between episodes of spirochetemia when bacterial densities are low, it is unknown whether ticks can acquire the spirochetes, become colonized by the bacteria, and subsequently transmit the bacteria once they feed again. We addressed these questions by feeding ticks, Omnithodoros hermsi Wheeler (Acari: Argasidae),daily on an infected mouse during low andhigh levels of spirochete infections. This study demonstrates that spirochete acquisition by the tick vector can occur during low levels of mammalian infection and that once a spirochetemic threshold is attained within the blood, nearly 100% of ticks become colonized by Borrelia hermsii.
蜱传回归热是由螺旋体属内的螺旋体引起的。这种疾病的标志是反复出现的发热发作和哺乳动物血液中的高螺旋体密度，这是由于免疫逃避造成的。在螺旋体血症发作期间，当细菌密度较低时，尚不清楚蜱是否可以获得螺旋体，被细菌定植，并在再次进食时传播细菌。我们通过每日给感染的老鼠喂食感染的 Omnithodoros hermsi Wheeler（蜱螨目：Argasidae）来解决这些问题，在低水平和高水平的螺旋体感染期间。这项研究表明，蜱虫载体可以在哺乳动物感染的低水平时获得螺旋体，并且一旦血液中的螺旋体血症阈值达到，几乎 100%的蜱都会被 Borrelia hermsii 定植。
