Pneumocystis jirovecii - mature field cyst (MET x12 000)

France, Dei-Cas Emmanuel

The cell wall of Pneumocystis jirovecii shows two layers. The outer is dense to electon micrograph whereas the inner less dense covered by the plasma membrane. The intracystic bodies, with one cell nucleus, present a round dense mitochondrion and a rough endoplasmic reticulum.