Pneumocystis carinii is a eukaryotic microorganism, which mainly has two forms: cyst and trophozoite. In the early stage of cyst, it is an intermediate form between them, and its morphological characteristics are unclear. The capsule is round or oval, with a diameter of 4 ~ 6 µ m and a wall thickness of 100 ~ 160nm. It is brown black when stained with silver and purple blue when stained with toluidine blue. After maturation, the cytoplasm in the capsule is absorbed, containing 8 intracapsular bodies with a diameter of 1 ~ 1.5 µ m, pleomorphic, thin membrane and mononuclear. After the rupture of the capsule, the small bodies in the capsule are released and develop into trophozoites. The trophozoites are not colored and reproduce by dichotomy. There are often a large number of trophozoites in the lungs of severely infected people. There are fewer cysts. Cyst is an important basis for diagnosis.
Common Health Issues