Ultrastructural study of globidian parasites infecting the abomasum of sheep in Germany.

Globidian parasites infecting the abomasum of sheep in Germany were investigated by means of electron microscopy. The frequency of infection was found to be 93 %. The globidian cyst-like bodies contained multinucleate schizonts, developing merozoites or fully developed merozoites. Among the latter there were two different types, namely short and long forms. The process of merozoite formation was described in detail. The giant schizonts were subdivided into multinucleate cell portions of irregular size and shape. Their nuclei were then arranged at the periphery of the cell portions and underwent their last division which was combined with the differentiation of merozoites. The long form merozoites were elongated cylindrical in shape with terminal nucleus. They measured 7.7 μm in length and 1.0 μm in width. The merozoites of the short type were spindle-shaped with a central nucleus. They were 5.0 μm long and 1.0 μm wide. The globidian parasites were located in a parasitophorous vacuole of an intact host cell.