【摘要】 对首次在乳牛粪便中发现的疑似环孢子虫卵囊的形状、大小、抗酸染色和孢子化等形态学特征进行了观察,探讨了该原虫的纯化方法。结果显示,牛源环孢子虫卵囊呈球形,直径6～10μm。直接涂片时可见卵囊内含折光性较强的成团小球体,呈桑椹胚状,淡绿色。碘液染色不着色。经改良抗酸染色后,卵囊着色变化较大,呈淡红色、深红色或不着色。新排出的未孢子化卵囊培养后可观察到孢子化的卵囊,内含2个孢子囊,每个孢子囊内含有2个折光性较强的子孢子。这些特征与人或其他动物的环孢子虫一致。环孢子虫感染阳性的粪便经Sheather’s蔗糖漂浮法浓集后,再经蔗糖密度梯度离心,可以得到较为纯净的卵囊。更多还原

【Abstract】 Cyclospora-like oocysts were found in dairy cattle feces.Using wet mount slides,the oocyst walls appeared as well-defined non-refractile spheres measuring 6 to 10μm in diameter,within each unsporulated oocyst was a central morula-like structure containing a variable number of inclusions.At a magnification of×1000,the inclusions were refractile,exhibiting a greenish tinge.Oocysts were stained variably using a modified acid-fast stains but colorless in saline wet mounts.Oocysts were concentrated and purified by sucrose flotation.Purified oocysts were suspended in equal volumes of 5% potassium dichro- mate solution to sporulate.The sporulated oocyst holds 2 sporocysts and each sporocyst contains 2 sporo- zoites,i.e.each oocyst contains a total of 4 sporozoites.All the above phenotypic characteristics were simi- lar to those described previously in human being.This is the first cyclosporan to be described in dairy cattle.更多还原