Lee K T, Little M D, Beaver P C
J Parasitol. 1975 Aug;61(4):585-98.
The persistence and precise location of Ancylostoma caninum larvae in tissues of vertebrate paratenic hosts and the nature of host responses were studied in mouse, cat, and monkey. Mice were infected percutaneously and examined at various intervals up to 260 days after exposure. Long-persisting larvae were found only in the muscles. Histologic sections revealed that within 4 hr after exposure some larvae had migrated through the skin and had entered individual fibers of the underlying muscles. After the 1st day nearly all larvae found in muscles were within fibers. Granuloma formation and encapsulation were not observed, suggesting that inside the fibers the larvae produced no direct inflammatory reaction. Only diffuse infiltration of inflammatory cells was observed in muscles and this appeared to be in response to destruction of muscle fibers. Larvae were similarly located in muscles of a cat and a rhesus monkey examined 16 and 17 days, respectively, after cutaneous exposure. The histologic changes observed in muscle fibers invaded by A. caninum larvae are similar to those observed in early Trichinella spiralis infections. The larvae of A. canninum lying coiled within the muscle fibers also bear superficial resemblance to the larvae of T. spiralis. A. caninum larvae were also recovered by tissue digestion from muscles of naturally infected dogs, which suggests that larvae reside in this location in the bitch prior to transfer to the neonate via the milk.
在小鼠、猫和猴体内研究了犬钩口线虫幼虫在脊椎动物转续宿主组织中的持久性、精确位置以及宿主反应的性质。小鼠经皮感染，并在暴露后长达260天的不同时间间隔进行检查。仅在肌肉中发现了长期存活的幼虫。组织学切片显示，暴露后4小时内，一些幼虫穿过皮肤并进入了下方肌肉的单个纤维中。第1天后，在肌肉中发现的几乎所有幼虫都在纤维内。未观察到肉芽肿形成和包囊，这表明在纤维内部，幼虫没有产生直接的炎症反应。仅在肌肉中观察到炎性细胞的弥漫性浸润，这似乎是对肌纤维破坏的反应。在皮肤暴露后分别于第16天和第17天检查的一只猫和一只恒河猴的肌肉中，幼虫的位置相似。在被犬钩口线虫幼虫侵入的肌纤维中观察到的组织学变化与在旋毛虫早期感染中观察到的相似。盘绕在肌纤维内的犬钩口线虫幼虫在外观上也与旋毛虫幼虫相似。通过组织消化也从自然感染犬的肌肉中回收了犬钩口线虫幼虫，这表明幼虫在通过乳汁转移至新生儿之前存在于母犬的该位置。
