Watanabe Kanji, Kikuchi Mihoko, Ohno Akio, Mohamed Raafat Taha, Nara Takeshi, Ubalee Ratawan, Senba Masachika, Iwasaki Takuya, Chen Honggen, Aoki Yoshiki, Hirayama Kenji
Department of Parasitology, Institute of Tropical Medicine, Nagasaki University, Nagasaki 852-8523, Japan.
Parasitol Int. 2004 Dec;53(4):293-9. doi: 10.1016/j.parint.2004.03.002.
As part of a search for good animal models for human schistosomiasis, two miniature pigs of the CLAWN strain (C-1, C-2) were inoculated percutaneously with 200 Schistosoma japonicum cercariae of the Chinese strain, and the subsequent infection was monitored parasitologically, pathologically and serologically. Egg excretion into feces began at 5 weeks post-infection (p.i.) and became pronounced from 8 weeks to 17-20 weeks p.i. The average number of eggs in 1 g feces of each pig at the peak period between 8 and 20 weeks were 288 and 277, respectively. C-1 and C-2 were killed and perfused at 27 and 47 weeks p.i. and adult worm numbers recovered were 35 and 15, respectively. C-2 had at least four pairs of viable mature worms but no detectable fecal eggs for a month before perfusion, suggesting that any produced eggs were not excreted into the feces during this period. Egg deposits associated with inflammatory reactions were observed by histological examination of the liver, spleen, pancreas, mesenteric lymph nodes, lung, and small intestine. This suggests that reduced fecal excretion of eggs into the feces did not correlate to reduced parasite numbers in the chronic phase of schistosomiasis. This is the first report showing the miniature pig to be a potential model for human S. japonicum infection.
作为寻找人类血吸虫病良好动物模型的一部分，给两只CLAWN品系的小型猪（C-1、C-2）经皮接种200条中国品系的日本血吸虫尾蚴，并从寄生虫学、病理学和血清学方面监测随后的感染情况。感染后5周（p.i.）开始有虫卵排至粪便中，8周龄至17 - 20周龄时排虫显著。在8至20周的高峰期，每头猪每克粪便中的虫卵平均数分别为288和277。分别在感染后27周和47周处死并灌注C-1和C-2，回收的成虫数量分别为35条和15条。C-2至少有四对存活的成熟虫体，但在灌注前一个月未检测到粪便虫卵，这表明在此期间产生的任何虫卵均未排至粪便中。通过对肝脏、脾脏、胰腺、肠系膜淋巴结、肺和小肠进行组织学检查，观察到与炎症反应相关的虫卵沉积。这表明在血吸虫病慢性期，粪便中虫卵排泄减少与寄生虫数量减少无关。这是首份表明小型猪可能是人类日本血吸虫感染模型的报告。
