Pohlenz J, Bemrick W J, Moon H W, Cheville N F
Vet Pathol. 1978 May;15(3):417-27. doi: 10.1177/030098587801500318.
Transmission and scanning electron microscopy of the ileal mucosae from 12 calves infected with Cryptosporidium sp. showed cryptosporidia free in the lumen and attached to epithelium. The attached parasites were interpreted to be extracellular and adherent to the microvillous border of epithelial cells. Stages of the organism included crescentic-free merozoites, trophozoites, schizonts, gametes and oocysts. Attached parasites were detected chiefly at villous tips and all stages were present on a single villus. Attachment sites were characterized by absence or disintegration of microvilli, disorganization of the terminal web and development of a specialized attachment zone. There were increased numbers of lysosomes and irregularities in the nuclear membrane of parasitized epithelial cells. It was concluded that cryptosporidia exist in bovine intestine as extracellular parasites and cause epithelial changes that in turn probably cause or contribute to diarrheal disease.
对12头感染隐孢子虫的犊牛回肠黏膜进行透射电子显微镜和扫描电子显微镜观察，结果显示隐孢子虫存在于肠腔中且附着于上皮细胞。附着的寄生虫被认为是细胞外的，并附着于上皮细胞的微绒毛边缘。该生物体的阶段包括新月形游离裂殖子、滋养体、裂殖体、配子和卵囊。附着的寄生虫主要在绒毛顶端被检测到，且所有阶段都存在于单个绒毛上。附着部位的特征是微绒毛缺失或解体、终末网紊乱以及形成一个特殊的附着区。被寄生的上皮细胞中溶酶体数量增加，核膜出现不规则变化。得出的结论是，隐孢子虫在牛肠道中作为细胞外寄生虫存在，并引起上皮细胞变化，进而可能导致或促成腹泻病。
