Isolation and identification of Cryptosporidium from various animals in Korea II. Identification of Cruptosporidium muyis from mice

한국산 동물로부터 크립토스포리디움의 분리 및 동정 II. 마우스로부터 Cryptosporidium muris의 분리

Each of SPF mice(Scl: ICR strain, 3-week-old males) was inoculated with 5$\times$104 oocysts of Cryptosporidium by stomach tube. The oocysts were large type one which was previously isolated from Korean mice, and passaged in 3-week-old SPF mice. The patterns of oocyst discharge were monitored daily, and in order to observe the ultrastructure of developmental stages the stomach of the mice was examined by transmission electron microscopy (TEM) at 4 weeks post-inoculation. The prepatent period for 6 mice was 5.6 days post-inoculation on the average, and the patent period was 63.2 days. The number of oocysts discharged per day from the mice reached peak on day 36.6 post-inoculation on the average. A large number of oocysts were found in fecal samples obtained from inoculated mice on days 30~50 post-inoculation. C. tsuris was larger than C. parvum at almost every developmental stages, the sixte difference being 1.4 times in oocysts, 2.4 times in sporozoites, 1.6 times in merozoites, and 1.5 times in microgametes. The ultrastructural features of the attachment site of C. tsuris to the mucus cells were remarkably different from those of C. parvum and its closely related species. The anterior projection of the protozoa (C. muris), the outer aspect of which was surrounded by a thick filamentous process of the host cell, has not been reported at any developmental stages of C. parvum or its closely related species. The size of the oocysts of strain RN 66 was larger than that of Korean mice origin. The above results reveal that the large type Cryptosporidium of Korean mice origin is identified as Cryptosporidium muris and this type was named as C. muris (strain MCR).

한국산 마우스로부터 분리한 크링토스포리디움(Cryptosporidium)의 대형 오오시스트 (C. muris)를 SPF 마우스에 경구 투여하여 분변 내 오오시스트 배출 양상과 투과전자현미경으로 위선 조직에서 발견되는 여러 발육기의 미세구조를 관찰하였다. 마우스에 있어서 prepatent period는 평균 5.6일, patent period 63.0±1.6일, 오오시스트 배출 정점기는 투여 후 36.6±2.8일째, 그리고 일반적으로 30일부터 50일까지 20일간에 걸쳐 다수의 오오시스트가 분변으로 배출되었다. 이 원충의 거의 모든 발육기의 크기는 C. Parwum보다 커서 오오시스트 1.4배, 스포로조이트 2.4배, 메로조이트 1.6배, 수생식체 1.5배이었다. 그리고, 숙주세포에 부착되어 있는 부위는 C. parwum의 것과 현저하게 다르므로 모든 발육기에서 바같쪽이 숙주의 두터운 사상돌기로 둘러싸여 있는 전단 돌출부를 볼 수 있었다. 또한, 한국산 마우스 유래 오오시스트가 strain RN 66의 것보다 다소 작았다. 이상의 결과를 기초로 하여 한국산 마우스 유래 크립토스포리디움을 C. maris라고 동정하였으며, Cryptesporidium tsuris(strain MCR)라고 명명하고자 한다.