Matsubayashi Makoto, Kimata Isao, Iseki Motohiro, Hajiri Tomoya, Tani Hiroyuki, Sasai Kazumi, Baba Eiichiroh
Department of Food and Nutrition, Osaka Joshi-Gakuen Junior College, Tennoji-ku, Osaka 543-0073, Japan.
Vet Parasitol. 2005 Apr 20;129(1-2):165-8. doi: 10.1016/j.vetpar.2005.01.003.
Previously, we reported 'a novel type' of Cryptosporidium andersoni detected from cattle in Japan, and showed that the isolate was infective to mice. In the present study, we examined the patterns of oocyst shedding in both immunocompromised and immunocompetent mice, as well as pathological lesions in the infected mice. After oral inoculation with 1 x 10(6) oocysts, all five severe combined immunodeficiency (SCID) mice began to shed endogenously produced oocysts on day 6 post-inoculation (p.i.). The number of oocysts per day (OPD) reached 1 x 10(6) on day 17 p.i., and an OPD level of 1 x 10(6) to 10(7) was maintained until 91 days p.i. when the mice were sacrificed. In the five immunocompetent mice inoculated with 1 x 10(6) oocysts, the pre-patent and patent periods were 6 and 19 days, respectively, and the maximal OPD level was 1.5 x 10(5) on average. On histological examinations of infected SCID mice, a large number of parasites were present on the surface of the gastric glands of the stomach, but not in other organs examined. In conclusion, the novel type of C. andersoni, which genetically coincides with C. andersoni reported in other countries, is infective to mice, but susceptibility was lower than that of Cryptosporidium muris infecting rodents from the perspective of infectivity to immunocompetent mice.
此前，我们报道了从日本牛体内检测到的一种“新型”安氏隐孢子虫，并表明该分离株对小鼠具有感染性。在本研究中，我们检测了免疫受损和免疫健全小鼠的卵囊排出模式以及感染小鼠的病理损伤。给5只严重联合免疫缺陷（SCID）小鼠经口接种1×10⁶个卵囊后，所有小鼠在接种后第6天开始排出内源性产生的卵囊。接种后第17天，每天的卵囊数（OPD）达到1×10⁶，直到接种后91天处死小鼠时，OPD水平维持在1×10⁶至10⁷。给5只免疫健全小鼠接种1×10⁶个卵囊后，潜伏期和发病期分别为6天和19天，平均最大OPD水平为1.5×10⁵。对感染的SCID小鼠进行组织学检查时，在胃的胃腺表面发现大量寄生虫，但在检查的其他器官中未发现。总之，这种新型安氏隐孢子虫在基因上与其他国家报道的安氏隐孢子虫一致，对小鼠具有感染性，但从对免疫健全小鼠的感染性来看，其易感性低于感染啮齿动物的微小隐孢子虫。
