Exserohilum

''Exserohilum'' is a genus of fungi in the family Pleosporaceae. The ''Exserohilum'' species are known for causing blight and human immune system diseases. The sexual reproductive (or ascigerous) states of Exserohilum species are known as Setosphaeria. The type species is ''Exserohilum turcicum''. This genus is among three dematiaceous that are categorized for containing pathogens leading to diseases like phaeohyphomycosis.

Morphology

''Exserohilum'' is an asexual organism that reproduces through spores. These one-celled reproductive units are concave and can be seen in the suspensor.

Taxonomy

''Exserohilum'' was circumscribed by K. Leonard and Edna Suggs in 1974 to contain species formerly placed in ''Bipolaris'' with distinctly protruding hila. Exsero which means stretch out and hilum which refers to the part of the organism. The truncate hila or hilum, protrudes from its distinct conidia which are ellipsoidal and distoseptate (forming a layer).

Colonies of ''Exserohilum'' range from the color grey to blackish-brown. The texture varies from suede-like to floccose in texture. The species also have an olivaceous to black reverse. The conidia from which the hilum extends, are either straight, curved, slightly bent or ellipsoidal to fusiform. and are formed on the top through a pore (poroconidia) on an elongated sympodial angled conidiophore. The strong, protruding truncate hilum and the septum above is normally thick and dark. The end cells are paler and the walls finely roughened. The conidial germination of ''Exserohilum'' is bipolar.

Habitat and distribution

''Exserohilum'' has a cosmopolitan distribution, with its species found naturally in warm, tropical, and subtropical locations. They live on plant material like grasses, rotten wood and in the soil.

Species

, Index Fungorum lists 26 valid species of ''Exserohilum'':
*'' Exserohilum antillanum'' R.F.Castañeda, Guarro & Cano 1995 – Cuba
*'' Exserohilum curvatum'' Sivan. & Muthaiyan 1984 – Venezuela
*''Exserohilum curvisporum'' Sivan., Abdullah & B.A.Abbas 1993 – Iraq
*'' Exserohilum echinochloae'' Sivan. 1984 – Bangladesh
*''Exserohilum frumentacei'' (Mitra) K.J.Leonard & Suggs 1974 – Andhra Pradesh; Bihar; Botswana; Ethiopia; Sabah
*''Exserohilum fusiforme'' Alcorn 1991 – Queensland
*''Exserohilum gedarefense'' (El Shafie) Alcorn 1983 – Egypt; Sudan
*''Exserohilum heteromorphum'' G.Y.Sun 2005
*''Exserohilum heteropogonicola'' Sivan. 1984 – Colombia; Uttaranchal
*''Exserohilum inaequale'' Sivan. 1984 – Nigeria
*''Exserohilum israeli'' Steiman, Guiraud, Seigle-Mur. & Sage 2000 – Israel
*'' Exserohilum longirostratum'' (Subram.) Sivan. 1984 – Andhra Pradesh; Florida; France; Haryana; Madhya Pradesh; Nigeria; Northern Territory; Puerto Rico; Rajasthan; Sudan; Uttar Pradesh; Zambia
*''Exserohilum longisporum'' G.Y.Sun 1997 – China
*''Exserohilum mcginnisii'' A.A.Padhye & Ajello 1986
*''Exserohilum minor'' Alcorn 1986
*''Exserohilum neoregeliae'' Sakoda & Tsukib. 2011
*''Exserohilum oryzae'' Sivan. 1987 – Macedonia
*''Exserohilum oryzicola'' Sivan. 1984
*''Exserohilum oryzinum'' Sivan. 1984 – Egypt
*''Exserohilum parlierense'' W.Q.Chen & Michailides 2002
*''Exserohilum paspali'' J.J.Muchovej & Nesio 1987 – Minas Gerais
*''Exserohilum phragmitis'' W.P.Wu 1990
*''Exserohilum protrudens'' Alcorn 1988
*''Exserohilum psidii'' Sivan. 1992 – Andhra Pradesh
*''Exserohilum sodomii'' Guiraud, Steiman, Seigle-Mur. & Sage 1997 – Israel
*''Exserohilum sorghicola'' Sivan. 1987 – Ethiopia

Clinical significance

Infection cases caused by exposure to ''Exserohilum'' are rare, but it's the most well studied detail of the fungi. The three species of ''Exserohilum'' that are identified as human pathogens are: '' Exserohilum Rostratum'', '' Exserohilum longirostratum'' and ''Exserohilum mcginnisii''. Prevailing infections include sinusitis, skin infection and in some rare cases, cerebral abscesses, keratitis, osteomyelitis, prothetic valve endocarditis, and disseminated infection. Reports of human infection by ''Exserohilum'' mainly come from warm, tropical and subtropical locations such as southern United States, India, and Israel.

References

External links

{{Taxonbar, from=Q10493219

Dothideomycetes genera
Pleosporaceae