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''Cryptosporidium'' is a genus of apicomplexan protozoans that can cause gastrointestinal illness with diarrhea in humans. Treatment is symptomatic, with fluid rehydration, electrolyte correction and management of any pain. ''Cryptosporidium'' oocysts are 4-6 µm in diameter and exhibit partial acid-fast staining. They must be differentiated from other partially acid-fast organisms including ''Cyclospora cayetanensis''. == General characteristics == ''Cryptosporidium'' causes the diarrhoeal illness cryptosporidiosis. Other apicomplexan pathogens include the malaria parasite ''Plasmodium'', and the toxoplasmosis parasite ''Toxoplasma''. Unlike ''Plasmodium'', which transmits via a mosquito vector, ''Cryptosporidium'' does not use an insect vector, and is capable of completing its lifecycle within a single host, resulting in cyst stages that are excreted in feces and are capable of transmission to a new host.〔http://www.cdc.gov/parasites/crypto/pathogen.html〕 A number of ''Cryptosporidium'' species infect mammals. In humans, the main causes of disease are ''C. parvum'' and ''C. hominis'' (previously ''C. parvum'' genotype 1). ''C. canis'', ''C. felis'', ''C. meleagridis'', and ''C. muris'' can also cause disease in humans.〔 Cryptosporidiosis is typically an acute, short-term infection, but can become severe and nonresolving in children and immunocompromised individuals. In humans, it remains in the lower intestine and may remain for up to five weeks.〔 The parasite is transmitted by environmentally hardy cysts (oocysts) that, once ingested, exist in the small intestine and result in an infection of intestinal epithelial tissue.〔 The genome of ''Cryptosporidium parvum'', sequenced in 2004, was found to be unusual amongst eukaryotes in that the mitochondria seem not to contain DNA. A closely related species, ''C. hominis'', also has its genome sequence available. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Cryptosporidium」の詳細全文を読む スポンサード リンク
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