| Trophozoite, precyst
and cyst stages of PC can be found suspended in a frothy, honeycombed
foamy exudate. Mature cysts contain eight intracystic bodies known as
sporozoites. Trophozoites are small and pleomorphic ranging from 1 to
5 µm in size. In Giemsa stain trophozoites contain red dot like
nucleus surrounded by pale blue cytoplasm. Precysts are oval measuring
4 to 6 µm without intracystic bodies, but may have one or more
nuclei. Mature cysts are thick & thin walled measuring 5 to 8 µm
containing intracystic bodies. Thin walled cysts rupture and release
sporozoites that in turn multiply by binary fission or initiate sexual
cycle. Giemsa stains intra cystic bodies and trophozoites, but does
not stain cyst walls.
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