贝氏隐孢子虫生活史的超微结构研究

ULTRASTRUCTURAL STUDY IN THE LIFE CYCLE OF CRYPTOSPORIDIUM BAILEYI

立文利用透射电镜观察了樱桃谷鸭贝氏隐孢子虫人工感染石歧杂鸡后法氏囊虫体生活史的超微结构。结果表明:各期虫体,除裂殖子、子孢子或小配子外,均寄生于微绒毛包围形成的带虫空泡内,但未与上皮细胞浆接触。在虫体和上皮细胞间存在附着带和营养器。成熟裂殖体具有8个或4个裂殖子、孢子化卵囊具有4个子孢子。裂殖子前端有顶泡、锥体前环、锥体、棒状体和微线。后端有致密体、粗面内质网、高尔基体和细胞核。但没有发现线粒体、多糖颗粒、微孔和膜下微管。大配子除具有1～4个成熟体和2种成囊壁颗粒外,还有多糖颗粒、粗面内质网和液泡。

The ultrastructure of tissue stages of Cryptosporidium baileyi parasitising the bursa Fabricii of Shiqiza chickens experimentally infected with parasites isolated from Cherry Valley ducks was studied by transmission electron microscopy. All the stages of the protozoon excepting the motile merozoites, sporozoites or microgametes were in parasitophorous vacuoles formed by microvilli but not in contact with the cytoplasm. Close contact of the parasite with the membrane of the epithelial cell was made by means of the parasite's adhesion zone and feeder organelle between the parasite and epithelial cell. The developed schizonts had eight or four merozoites and the sporulated oocysts had four sporozoites. The anterior end of the merozoite consisted of an apical vesicle, preconoidal ring and conoid. The anterior portion of the merozoite contained rhoptries and micronemes while the posterior portion contained dense bodies, endoplasmic reticulum, golgi bodies and nucleus. No mi-cothondria, polysaccharide granules, micropore or microtubules were found. The macrogametes had 1-4 maturation bodies and two types of wall-forming bodies, as well as polysaccharide granules, endoplasmic reticulum and lipid body.