FIG. 7.

Diagrammatic representation of the characteristic features of a host cell infected with Enterocytozoon bieneusi as seen with the transmission electron microscope. Note that the development takes place in the absence of a parasitophorous vacuole. All stages of the parasite develop within the host cell cytoplasm. The structure formed at early stages of development during the course of infection is called a plasmodium (P) and may contain one or more nuclei. The cell surface of the plasmodium thickens during further development, leading to the formation of sporogonial plasmodium (PL), which divides to form several sporoblast cells. The sporoblasts develop into spores (S). V, posterior vacuole; HN, host cell nucleus.