Geotrichum is a genus of

fungi A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...

found worldwide in soil, water, air, and sewage, as well as in plants, cereals, and dairy products; it is also commonly found in normal human flora and is isolated from sputum and feces. It was first described in 1809 by Johann Heinrich Friedrich Link. The genus ''Geotrichum'' includes over 100

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

. Some are welcome and even considered desirable. For example, skilled cheesemakers create conditions favorable for the formation of a ''Geotrichum candidum'' rind on certain goat's milk and cow's milk cheeses, proudly declaring the rind to be the most flavorful part of such cheeses. Another example is the presence of some Geotrichum species in fermented poi. The most clinically relevant species is '' Saprochaeta capitata'', formerly known as ''Geotrichum capitatum'', with most cases occurring in Europe. '' Saprochaete clavata'', formerly known as '' Geotrichum clavatum'', is an uncommon infection that has been associated with sporadic outbreaks. ''

Geotrichum candidum ''Geotrichum candidum'' is a fungus which is a member of the human microbiome, notably associated with skin, sputum, and faeces where it occurs in 25–30% of specimens. It is common in soil and has been isolated from soil collected around the w ...

'' is closely related to '' Saprochaeta'' sp., rarely isolated but may cause invasive and disseminated disease with high mortality

Yeast Yeasts are eukaryotic, single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and at least 1,500 species are currently recognized. They are estimated to constit ...

-like and

mold A mold () or mould () is one of the structures certain fungi can form. The dust-like, colored appearance of molds is due to the formation of spores containing fungal secondary metabolites. The spores are the dispersal units of the fungi. Not ...

-like strains have been identified. The most important risk factor for invasive fungal infection related to ''Geotrichum'' is severe immunosuppression, especially in hematological malignancies as

acute leukemia Acute leukemia or acute leukaemia is a family of serious medical conditions relating to an original diagnosis of leukemia. In most cases, these can be classified according to the lineage, myeloid or lymphoid, of the malignant cells that grow unco ...

, associated with profound and prolonged neutropenia. Fungemia is very common, often with deep organ involvement (lung, liver, spleen, and central nervous system) and also skin and mucous membranes lesions. There is no optimal treatment for ''Geotrichum'' infections but based on existing data guidelines recommend

amphotericin B Amphotericin B is an antifungal medication used for serious mycosis, fungal infections and leishmaniasis. The fungal infections it is used to treat include mucormycosis, aspergillosis, blastomycosis, candida infections, candidiasis, coccidioidomy ...

with or without co-administered

flucytosine Flucytosine, also known as 5-fluorocytosine (5-FC), is an antifungal medication. It is specifically used, together with amphotericin B, for serious ''Candida'' infections and cryptococcosis. It may be used by itself or with other antifungals for ...

or with

voriconazole Voriconazole, sold under the brand name Vfend among others, is an antifungal medication used to treat a number of fungal infections. This includes aspergillosis, candidiasis, coccidioidomycosis, histoplasmosis, penicilliosis, and infections by ...

showing good in vitro susceptibility. Mortality associated with Geotrichum-related infections is high, ranging from 57% to 80%. Increasing the knowledge on ''Geotrichum'' related invasive fungal infections may improve early diagnosis and adequate treatment of these severe infections.

History

The genus ''Geotrichum'' was described by Johann Heinrich Friedrich Link in 1809 to accommodate the species ''G. candidum'' found on decaying leaves. Since then, over 130 taxa have been described in the genus, and hundreds of synonyms have been generated. For example ''G. candidum'' was misclassified as the ''Oidium lactis'' in much early literature. Species of ''Geotrichum'' resemble the genera '' Trichosporon'' and ''Protendomycopsis''; however, ''Geotrichum'' is of ascomycetous affiliation whereas the latter are members of the Basidiomycota. Species of ''Geotrichum'' are occasionally mistaken for fast growing members of the genus ''

Dipodascus ''Dipodascus'' is a genus of fungi in the family Dipodascaceae The Dipodascaceae are a family of yeasts in the order Saccharomycetales. According to the 2007 Outline of Ascomycota, the family contains four genera; however, the placement of ''Sp ...

'', which are characterized by irregularly branched, 10-14 μm wide hyphae and the production of single-spored asci. However, unlike ''Geotrichum'', members of the genus ''Dipodascus'' lack dichotomous branching of the peripheral hyphae and their growth rates are generally less than 3 mm per day.

Species

Species in this genus include the following: *'' Geotrichum amycelicum'' *'' Geotrichum armillariae'' *'' Geotrichum asteroides'' *'' Geotrichum beigelii'' *'' Geotrichum bipunctatum'' *'' Geotrichum bogolepoffii'' *'' Geotrichum bostonense'' *'' Geotrichum brasiliense'' *'' Geotrichum brocianum'' *'' Geotrichum brocqii'' *'' Geotrichum brocquii'' *'' Geotrichum bryndzae'' *'' Geotrichum byssinum'' *''

'' Link 1809 **'' Geotrichum candidum var. citri-aurantii'' ( Ferraris) Cif. & F. Cif. 1955 *'' Geotrichum caoi'' *'' Geotrichum capitatum'' *'' Geotrichum carabidarum'' *'' Geotrichum cerebrinum'' *'' Geotrichum cinereum'' *'' Geotrichum cinnamomeum'' *'' Geotrichum citri-aurantii'' *'' Geotrichum clavatum'' *'' Geotrichum coccophilum'' *'' Geotrichum coremiiforme'' *'' Geotrichum cuboideum'' *'' Geotrichum cucujoidarum'' *'' Geotrichum cutaneum'' *'' Geotrichum cyphellae'' *'' Geotrichum decipiens'' *'' Geotrichum dermatitidis'' *'' Geotrichum doliiforme'' *'' Geotrichum dombrayi'' *''

Geotrichum dulcitum Geotrichum is a genus of fungi found worldwide in soil, water, air, and sewage, as well as in plants, cereals, and dairy products; it is also commonly found in normal human flora and is isolated from sputum and feces. It was first described in 1 ...

'' *'' Geotrichum eriense'' *'' Geotrichum europaeum'' *'' Geotrichum famatum'' *'' Geotrichum fermentans'' *''

Geotrichum fici Geotrichum is a genus of fungi found worldwide in soil, water, air, and sewage, as well as in plants, cereals, and dairy products; it is also commonly found in normal human flora and is isolated from sputum and feces. It was first described in ...

References

{{- Saccharomycetes Fungal plant pathogens and diseases Animal fungal diseases Taxa named by Johann Heinrich Friedrich Link Ascomycota genera