Takahashi M, Murata M, Hori E, Tanaka H, Kawamura A
Department of Parasitology, Saitama Medical School, Japan.
Jpn J Exp Med. 1990 Aug;60(4):203-8.
Transmission of Rickettsia tsutsugamushi (Rt) from a rodent to trombiculid mites was studied. Wild rodents, Apodemus speciosus, were subcutaneously inoculated with Karp strain of Rt, and larval trombiculid mites were released on the ear lobes for feeding, 10 and 20 days after infection. Isolation of Rt was performed from individual mites or pools of 2 to 7 mites by the mouse passage method. From Apodemus 10 days after Rt infection, possibly at the time of high rickettsiaemia, the infection rates among mites were 4/44 (9.1%) or higher in Leptotrombidium fuji, 1/20 (5%) in L. pallidum and 0/41 in L. deliense. From Apodemus 20 days after infection, no mite was infected in 50 L. fuji or 7 L. pallidum possibly due to reduced rickettsiaemia. Transmission of Rt from rodent to mite was proven to occur at low probability on appropriate conditions but not by the incidental chance.
研究了恙虫病东方体（Rt）从啮齿动物传播至纤恙螨的过程。将野生啮齿动物日本姬鼠皮下接种Rt的Karp株，在感染后10天和20天，将幼虫纤恙螨置于耳垂上以供取食。通过小鼠传代法从单个螨或2至7个螨的组中分离Rt。在Rt感染日本姬鼠10天后，可能在立克次体血症高峰期，富士纤恙螨的螨感染率为4/44（9.1%）或更高，苍白纤恙螨为1/20（5%），地里纤恙螨为0/41。在感染日本姬鼠20天后，50只富士纤恙螨或7只苍白纤恙螨中均无螨感染，这可能是由于立克次体血症减少所致。已证明，在适当条件下，Rt从啮齿动物到螨的传播以低概率发生，但并非偶然发生。
