Cryptosporidium sp., an intracellular protozoan parasite. Using a modified cold Kinyoun acid-fast staining technique, and under an oil immersion lens the Cryptosporidium sp. oocysts, which are acid-fast stain red, and the yeast cells, which are not acid-fast stain green(picture1).
It exists in either the free-swimming (trophozoite) form or the oocyst (dormant) form. Cryptosporidium parvum is now recognized as a human pathogen which can cause severe diarrheal illness.
Big problem for immunocompromised patients (AIDS).