美麗食道虫の実験動物および羊における感染実験 Experimental Infection of Laboratory Animals and Sheep with Gongylonema pulchrum in Japan

青森県六ヶ所村産の糞食性甲虫から分離した美麗食道虫の感染幼虫を兎,ラット,マウス,羊および猫に経口投与し,感染性を検討した.投与後7,14および19週の虫体回収率は兎で高く,マウスと猫から虫体は検出されなかった.虫体は食道を中心に口腔から胃噴門部の粘膜に寄生し,その発育は兎と羊でほぼ同様であった.これらの結果から,本線虫の実験的終宿主としての兎の好適性が示唆された.

Japanese White rabbits, Wistar rats, ddY mice, Suffolk sheep, and a domestic cat were each orally inoculated with 20-140 third-stage larvae (L3) of <i>Gongylonema pulchrum</i>, isolated from naturally infected dung beetles captured in Aomori Prefecture. Worm recovery rates were 40.0-72.0% in rabbits at 7, 14, and 19 weeks post-infection (PI) and 3.3-25.0% in rats at 19 weeks PI. Those in 2 sheep at 7 weeks PI showed 53.6% and 29.3%. No worms were recovered from the mice and the cat. In the susceptible animals, many worms were found in the esophagus, and a few were present in the pharyngeal mucosa, tongue, buccal mucosa, and cardiac portion of the stomach wall. No distinct morphological differences were observed in the worms from rabbits and sheep. These results indicate that rabbits are very suitable experimental definitive hosts for <i>G. pulchrum</i>.<br>