Cryptococcus
562574
223997971
2008-07-06T21:47:02Z
Ka Faraq Gatri
6892069
Category:Teliomycotina
{{Taxobox
| name = ''Cryptococcus''
| image = Cryptococcus_neoformans_using_a_light_India_ink_staining_preparation_PHIL_3771_lores.jpg
| image_caption = ''Cryptococcus neoformans''
| regnum = [[Fungi]]
| phylum = [[Basidiomycota]]
| subphylum = [[Basidiomycotina]]
| classis = [[Urediniomycetes]]
| ordo = [[Sporidiales]]
| familia = [[Sporidiobolaceae]]
| genus = '''''[[Filobasidiella]] (Cryptococcus)'''''
}}
'''''Cryptococcus''''' (literally "Hidden Seed") is a [[genus]] of [[fungus]]. It grows in culture as a [[yeast]]. The perfect (sexual) form or [[teleomorph]] is called '''Filobasidiella''', but the imperfect (asexual) form or [[anamorph]] is called '''Cryptococcus'''. The name Cryptococcus is correct when used in a medical context because the infective form is the imperfect form.
''[[Cryptococcus neoformans]]'' is the most prominent medically important [[species]]. It is best known for causing a severe form of [[meningitis]] and meningo-encephalitis in people with [[HIV]]/[[AIDS]]. There are about 37 recognized species of ''Cryptococcus'', but the [[taxonomy]] of the group is currently being re-evaluated with up-to-date methods. The majority of species live in the soil and are not harmful to humans. Very common species include ''Cryptococcus laurentii'' and ''Cryptococcus albidus''. Of all species, ''[[Cryptococcus neoformans]]'' is the major human and animal pathogen. However, ''Cryptococcus laurentii'' and ''Cryptococcus albidus'' have been known to occasionally cause moderate-to-severe disease in human patients with compromised immunity (owing to HIV infection, cancer chemotherapy, metabolic immunosuppression, ''et cetera'') <ref>Cheng MF, Chiou CC, Liu YC, Wang HZ, Hsieh KS (2001) ''Cryptococcus laurentii'' fungemia in a premature neonate. Journal of Clinical Microbiology. 39(4):1608-11. - a good review of ''C. laurentii'' cases till year 2000.</ref> <ref>[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=PureSearch&db=pubmed&details_term=%28%28%22cryptococcus%22%5BMeSH%20Terms%5D%20OR%20%28%22cryptococcosis%22%5BTIAB%5D%20NOT%20Medline%5BSB%5D%29%20OR%20%22cryptococcosis%22%5BMeSH%20Terms%5D%20OR%20cryptococcus%5BText%20Word%5D%29%20AND%20albidus%5BAll%20Fields%5D%20AND%20%28%22infection%22%5BMeSH%20Terms%5D%20OR%20%28%22communicable%20diseases%22%5BTIAB%5D%20NOT%20Medline%5BSB%5D%29%20OR%20%22communicable%20diseases%22%5BMeSH%20Terms%5D%20OR%20infection%5BText%20Word%5D%29%29%20AND%20%22humans%22%5BMeSH%20Terms%5D Results from a PubMed Search on terms: "Cryptococcus albidus Infection"] - list of references for ''C. albidus'' clinical infections.</ref>
''[[Cryptococcus gattii]]'' (or ''Cryptococcus neoformans'' var ''gattii'') is endemic to tropical parts of the continent of Africa and Australia. It is capable of causing disease in non-immunocompromised people. It is has been isolated from [[eucalyptus]] trees in Australia. Since 1999, there has been an outbreak of cryptococcus gattii infections in eastern [[Vancouver Island]],<ref>{{cite journal | author=Lindberg J, Hagen F, Laursen A, ''et al.'' | title=''Cryptococcus gattii'' risk for tourists visiting Vancouver lsland, Canada | journal=Emerg Infect Dis | year=2007 | volume=13 | pages=178–79 }}</ref> an area not generally thought to be endemic for this organism. Cases have since been described in the [[Pacific northwestern United States]].<ref>{{cite journal | author=MacDougall L, Kidd SE, Galanis E, ''et al.'' | title=Spread of ''Cryptoccus gattii'' in British Columbia, Canada and detection in the Pacific Northwest, USA | journal=Emerg Infect Dis | year=2007 | volume=13 | pages=42–50 }}</ref>
The cells of these species are covered in a thin layer of glycoprotein capsular material that has a gelatin-like consistency and that, among other functions, serves to help extract nutrients from the soil. But ''C. neoformans'' capsule is different in being richer in glucuronic acid and mannose, having O-acetyl groups <ref>Ross A, Taylor IE (1981) Extracellular glycoprotein from virulent and avirulent Cryptococcus species. Infection and Immunity. 31(3):911-8</ref>, and functioning as the major virulence factor in cryptococcal infection and disease.<ref>Casadevall A and Perfect JR (1998) Cryptococcus neoformans. American Society for Microbiolgy, ASM Press, Washington DC, 1st edition.</ref>
==References==
{{reflist}}
[[Category:Teliomycotina]]
[[Category:Yeasts]]
{{yeast-stub}}
[[de:Cryptococcus]]
[[id:Kriptokokus]]
[[ru:Криптококк]]