View source for Trichosporon

{{Short description|Genus of fungi}}
{{Automatic_taxobox
| image = Excessive dandruff.jpg
| image_caption = A typical case of severe dandruff and dry scalp
| taxon = Trichosporon
| authority = [[Gustav Behrend|Behrend]] (1890)
| type_species = ''Trichosporon beigelii'' 
| type_species_authority = (Küchenm. & [[Gottlob Ludwig Rabenhorst|Rabenh.]]) [[Jean Paul Vuillemin|Vuill.]]
| synonyms = 
}}


'''''Trichosporon''''' is a [[genus]] of [[anamorph]]ic [[fungi]] in the [[family (biology)|family]] [[Trichosporonaceae]]. All [[species]] of ''Trichosporon'' are [[yeast]]s with no known [[teleomorph]]s (sexual states). Most are typically isolated from soil, but several species occur as a natural part of the [[skin flora|skin microbiota]] of humans and other animals. Proliferation of ''Trichosporon'' yeasts in the hair can lead to an unpleasant but non-serious condition known as [[white piedra]]. ''Trichosporon'' species can also cause severe [[opportunistic infection]]s ([[trichosporonosis]]) in [[immunocompromised]] individuals.

==Taxonomy==
The genus was first described by the German [[dermatologist]] [[Gustav Behrend]] in 1890, based on yeasts isolated from the hairs of a [[moustache]] where they were causing the condition known as "[[white piedra]]".<ref name="Guého1992"/> Behrend called his new species ''[[Trichosporon ovoides]]''. [[Friedrich Küchenmeister]] and [[Gottlob Ludwig Rabenhorst|Rabenhorst]] had, however, previously described a species in 1867 from the hairs of a wig. They thought that the organism was an [[alga]] and placed it in the genus ''[[Pleurococcus]]'' as ''Pleurococcus beigelii''. The French mycologist [[Jean Paul Vuillemin|Vuillemin]] later realized it was a [[yeast]] and transferred it to the genus ''Trichosporon'', considering it to be an earlier name for ''Trichosporon ovoides''.

Over 100 additional yeast species were referred to ''Trichosporon'' by later authors.<ref name="Fungorum:Trichosporon"/> With the advent of [[DNA sequencing]], however, it became clear that many of these additional species belonged in other genera. Based on [[cladistic]] analysis of DNA sequences, 12 species are now accepted in the genus.<ref name="Liu2015"/>

DNA sequencing has also shown that white piedra can be caused by more than one ''Trichoporon'' species. As a result, ''Trichosporon beigelii'' has become a name of uncertain application.  McPartland & Goff selected a [[type (biology)|neotype]] strain that makes ''T. beigelii'' synonymous with ''[[Cutaneotrichosporon cutaneum]]''.<ref name="McPartland&Goff"/><ref name="CBSYeastDatabase"/> Guého and others, however, have argued that ''T. beigelii'' should be discarded (as a dubious name) and Behrend's original ''T. ovoides'' (for which a neotype strain has also been selected) should become the type.<ref name="Guého1992"/>  As a result of this uncertainty, the name ''T. beigelii'' is now obsolete.<ref name="UnivAdelaide"/>

==Description and habitat==
''Trichosporon'' species are distinguished microscopically by having yeast cells that germinate to produce hyaline [[hypha]]e that disarticulate at the [[septum|septa]], the hyphal compartments acting as [[Arthroconidium|arthroconidia]] (asexual propagules). No [[teleomorph]]ic (sexual) states are known.

Species of ''Trichosporon'' and related genera are widespread and have been isolated from a wide range of substrates, including human hair (''Trichosporon ovoides''), soil (''Cutaneotrichosporon guehoae''), [[cabbage]]s (''Apiotrichum brassicae''), [[cheese]] (''T. caseorum''), [[Scarabaeidae|scarab beetles]] (''Apiotrichum scarabaeorum''), [[parrot]] droppings (''T. coremiiforme''), and [[sea water]] (''Cutaneotrichosporon dermatis'').<ref name="Middelhoven2004"/>

==Human pathogens==
Several ''Trichosporon'' species occur naturally as part of the [[skin flora|microbiota of human skin]]. Occasionally, particularly in circumstances of high humidity, the fungus can proliferate, causing an unpleasant but harmless hair condition known as [[white piedra]]. Soft, pale nodules containing yeast cells and arthroconidia form on hairs of the scalp and body. The species responsible include ''Trichosporon ovoides'', ''[[Trichosporon inkin|T. inkin]]'',<ref name="Magalhães2008"/> ''[[Trichosporon asahii|T. asahii]]'', ''Cutaneotrichosporon mucoides'', ''T. asteroides'', and ''[[Cutaneotrichosporon cutaneum]]''. The obsolete name ''T. beigelii'' was formerly applied to all or any of these species.<ref name="Schwartz&Altman"/>

Much more serious [[opportunistic infection]]s, collectively called [[trichosporonosis]], have been reported in [[immunocompromised]] individuals. Species said to be agents of trichosporonosis are ''T. asahii'', ''T. asteroides'', ''[[Cutaneotrichosporon cutaneum]]'', ''Cutaneotrichosporon dermatis'', ''T. dohaense'', ''T. inkin'', ''Apiotrichum loubieri'', ''Cutaneotrichosporon mucoides'', and ''T. ovoides''.<ref name="Sugita1998"/><ref name="Marty2003"/><ref name="Taj-Aldeen2009"/>

== Species ==
{{div col begin|colwidth=30em}}
*''[[Trichosporon aquatile]]'' <small></small>
*''[[Trichosporon asahii]]'' <small></small>
*''[[Trichosporon asteroides]]'' <small></small>
*''[[Trichosporon caseorum]]'' <small></small>
*''[[Trichosporon coremiiforme]]'' <small></small>
*''[[Trichosporon dohaense]]'' <small></small>
*''[[Trichosporon faecale]]'' <small></small>
*''[[Trichosporon inkin]]'' <small></small>
*''[[Trichosporon insectorum]]'' <small></small>
*''[[Trichosporon japonicum]]'' <small></small>
*''[[Trichosporon lactis]]'' <small></small>
*''[[Trichosporon ovoides]]'' <small></small>
{{div col end}}

==References==
{{Reflist|2|refs=

<ref name="Fungorum:Trichosporon">{{cite web |url=http://www.indexfungorum.org/Names/genusrecord.asp?RecordID=10296 |title=Genus Record Details-''Trichosporon'' |publisher=CAB International |work= Index Fungorum|access-date=2010-04-30}}</ref>

<ref name="Middelhoven2004">{{cite journal |vauthors=Middelhoven WJ, Scorzetti G, Fell JW |year=2004 |title=Systematics of the anamorphic basidiomycetous yeast genus ''Trichosporon'' Behrend with the description of five novel species |journal=International Journal of Systematic and Evolutionary Microbiology |volume=54 |pages=975–986 |pmid=15143052 |doi=10.1099/ijs.0.02859-0 |issue=Pt 3 |doi-access=free }}</ref>

<ref name="Liu2015">{{cite journal |vauthors=Liu XZ, Wang QM, Göker M, Groenewald M, Kachalkin AV, Lumbsch HT, Millanes AM, Wedin M, Yurkov AM, Boekhout T, Bai FY |year=2015 |title=Towards an integrated phylogenetic classification of the Tremellomycetes |journal=Studies in Mycology |volume=81 |pages=85–147 |doi=10.1016/j.simyco.2015.12.001|pmid=26955199 |pmc=4777781 |doi-access=free }}</ref>

<ref name="Guého1992">{{cite journal |vauthors=Guého E, de Hoog GS, Smith MT |year=1992 |title=Neotypification of the genus ''Trichosporon''  |journal=Antonie van Leeuwenhoek |volume=61 |pages=285–288 |pmid=1497333 |issue=4 |doi=10.1007/bf00713937|s2cid=43889990 }}</ref>

<ref name="McPartland&Goff">{{cite journal |last1=McPartland |first1=JM |last2=Goff |first2=JP |year=1991 |title=Neotypification of ''Trichosporon beigelii'': morphological, pathological and taxonomic considerations |journal=Mycotaxon |volume=41 |pages=173–178 |id={{INIST|5366626}} }}</ref>

<ref name="CBSYeastDatabase">http://www.cbs.knaw.nl/Yeast/BioloMICS.aspx?Link=T&DB=0&Table=0&Descr=CBS%202466&Fields=All&ExactMatch=T{{Dead link|date=October 2023 |bot=InternetArchiveBot |fix-attempted=yes }}{{full citation needed|date=June 2015}}</ref>

<ref name="UnivAdelaide">Mycology Online: ''Trichosporon asahii'' {{cite web|url=http://www.mycology.adelaide.edu.au/virtual/2008/ID2-Apr08.html |access-date=May 1, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100212114446/http://www.mycology.adelaide.edu.au/virtual/2008/ID2-Apr08.html |archive-date=February 12, 2010 |title=Mould Identification: A Virtual Self Assessment &#124; Mycology Online }}{{full citation needed|date=June 2015}}</ref>

<ref name="Magalhães2008">{{cite journal |vauthors=Magalhães AR, Bona de Mondino SS, da Silva M, Nishikawa MM |year=2008 |title=Morphological and biochemical characterization of the aetiological agents of white piedra |journal=Mem. Inst. Oswaldo Cruz |volume=103 |pages=786–790 |pmid=19148418 |issue=8 |doi=10.1590/s0074-02762008000800008 |doi-access=free |hdl=1807/57587 |hdl-access=free }}</ref>

<ref name="Schwartz&Altman">{{EMedicine|article|1092330|Piedra}}</ref>

<ref name="Sugita1998">{{cite journal |vauthors=Sugita T, Nishikawa A, Shinoda T |year=1998 |title=Rapid detection of species of the opportunistic yeast ''Trichosporon'' by PCR |journal= Journal of Clinical Microbiology |volume=36 |pages=1458–1460 |pmid=9574732 |issue=5 |doi=10.1128/JCM.36.5.1458-1460.1998 |pmc=104855 }}</ref>

<ref name="Marty2003">{{cite journal |vauthors=Marty FM, Barouch DH, Coakley EP, Baden LR |year=2003 |title=Disseminated trichosporonosis caused by ''Trichosporon loubieri'' |journal=Journal of Clinical Microbiology |volume=41 |pages=5317–5320 |pmid=14605194 |doi=10.1128/JCM.41.11.5317-5320.2003 |issue=11 |pmc=262469 }}</ref>

<ref name="Taj-Aldeen2009">{{cite journal |vauthors=Taj-Aldeen SJ, Al-Ansari N, El Shafei S, Meis JF, Curfs-Breuker I, Theelen B, Boekhout T |year=2009 |title=Molecular identification and susceptibility of ''Trichosporon'' species isolated from clinical specimens in Qatar: Isolation of ''Trichosporon dohaense'' Taj-Aldeen, Meis & Boekhout sp. nov. |journal=Journal of Clinical Microbiology |volume=47 |pages=1791–1799 |issue=6 |pmid=19321719 |doi=10.1128/JCM.02222-08 |pmc=2691106 }}</ref>

}}

==External links==
* {{MeshName|Trichosporon}}

{{Mycoses}}
{{Taxonbar|from=Q3272399}}

[[Category:Tremellomycetes]]
[[Category:Yeasts]]