Histoplasma

{{Automatic taxobox

|image =Histoplasma capsulatum (8538519681).jpg

|image_caption = Tuberculate macroconidia of Histoplasma capsulatum

|taxon = Histoplasma

|authority = Darling (1906)

| type_species = Histoplasma capsulatum

| type_species_authority = Darling (1906)

| subdivision_ranks = Species

| subdivision = Histoplasma capsulatum

Histoplasma duboisii

Histoplasma mississippiense (nom. inval.)

Histoplasma ohiense (nom. inval.)

Histoplasma suramericanum (nom. inval.)

}}

Histoplasma is a genus of fungi in the order Onygenales. Species are known human pathogens producing yeast-like states under pathogenic conditions. They are the causative agents of histoplasmosis in humans and epizootic lymphangitis in horses.OIE Manual of Diagnostic Tests and Vaccines for Terrestrial Animals 2004 Chapter 2.5.13, {{cite web |url=http://www.oie.int/eng/normes/mmanual/A_00091.htm |title=Archived copy |accessdate=2007-06-14 |url-status=dead |archiveurl=https://web.archive.org/web/20070804182644/http://www.oie.int/eng/normes/MMANUAL/A_00091.htm |archivedate=2007-08-04 }}

Forms and stages

Histoplasma species have two forms: their environmental form is hyphal with microconidia and tuberculate macroconidia while their pathogenic form is a small intracellular yeast that exhibits narrow-necked budding{{cite book|chapter=Histoplasma Capsulatum: Mechanisms for Pathogenesis|last1=Mittal|first1=Jamie|last2=Ponce|first2=Maria G.|last3=Gendlina|first3=Inessa|last4=Nosanchuk|first4=Joshua D.|pmid=30043340|pmc=7212190|title=Fungal Physiology and Immunopathogenesis|pages=157–191|isbn=978-3-030-30236-8|publisher=Springer Nature Switzerland AG|year=2019|editor-last=Rodrigues|editor-first=Marcio L.|series=Current Topics in Microbiology and Immunology volume 422|volume=422 |doi=10.1007/82_2018_114}} and no capsule.{{cite journal|last=Mahajan|first=Monika|title=Etymologia: Histoplasma capsulatum|year=2021|journal=Emerging Infectious Diseases|volume=27|issue=3|page=969|doi=10.3201/eid2703.et2703|doi-access=free|pmc=7920646}}{{Cite journal|last=Hutton|first=JP|date=April 1985|title=Hyphal forms of Histoplasma capsulatum. A common manifestation of intravascular infections|url=https://pubmed.ncbi.nlm.nih.gov/3885898/|journal=Archives of Pathology and Laboratory Medicine|volume=109|issue=4|pages=330–332|pmid=3885898|via=Pubmed}} Infection occurs through inhalation of microconidia or small mycelial fragments. The dimorphic mold-yeast transforms and enters host macrophages and proliferates within them. Infections are most often seen in immunodeficient individuals.{{Cite journal|last=Lopez|first=CE|date=Oct 2006|title=Dimorphism and pathogenesis of Histoplasma capsulatum|url=https://pubmed.ncbi.nlm.nih.gov/17370580/|journal=Revista Argentina de Microbiologia|volume=38|issue=4|pages=235–242|pmid=17370580|via=Pubmed}}

Species are mainly found in the Ohio and Mississippi River Valleys in the United States (H.ohiense and H. mississippiense) as well as Central (H. capsulatum) and South America (H. suramericanum), Africa (H. duboisii), Asia, and Australia.{{Cite web|last=|first=|date=28 October 2020|title=Histoplasmosis|url=https://www.cdc.gov/fungal/diseases/histoplasmosis/index.html|archive-url=|archive-date=|access-date=27 January 2021|website=Centers for Disease Control and Prevention}}

References

{{Reflist|refs=

{{cite journal |vauthors=Jiang Y, Dukik K, Munoz JF, Sigler L, Schwartz IS, Govender NP, Kenyon C, Feng P, van den Ende BG, Stielow JB, Stchigel AM, Lu H, de Hoog S |title=Phylogeny, ecology and taxonomy of systemic pathogens and their relatives in Ajellomycetaceae (Onygenales): Blastomyces, Emergomyces, Emmonsia, Emmonsiellopsis |journal=Fungal Diversity |year=2018 |volume=90 |pages=245–291 |doi=10.1007/s13225-018-0403-y|doi-access=free |hdl=10067/1520590151162165141 |hdl-access=free }}

{{cite journal |vauthors=Sepúlveda VE, Márquez R, Turissini DA, Goldman WE, Matute DR |year=2017 |title=Genome sequences reveal cryptic speciation in the human pathogen Histoplasma capsulatum |journal=mBio |volume=8 |issue=6 |pages=e01339-17 |doi=10.1128/mbio.01339-17 |doi-access=free |pmid=29208741 |pmc=5717386 }}

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Category:Onygenales

Category:Eurotiomycetes genera

Category:Taxa described in 1906