Geotrichum candidum

Species of the genus Geotrichum produce chains of hyaline, smooth, one-celled, subglobose to cylindrical, slimy arthroconidia (ameroconidia) by the holoarthric fragmentation of undifferentiated hyphae. The arthroconidia, which are quite variable in size, may germinate at one end giving the appearance of a bud. However, the latter develops into a septate mycelium. True blastoconidia production is not found in the genus. This characteristic distinguishes the genus Geotrichum from Trichosporon, which usually does produce blastoconidia.

On Sabouraud's dextrose agar, colonies are fast growing, flat, white to cream, dry and finely suede-like with no reverse pigment. Hyphae are hyaline, septate, branched and break up into chains of hyaline, smooth, one-celled, subglobose to cylindrical arthroconidia. They are 6-12 x 3-6 um in size and are released by the separation of a double septum.

Arthroconidium development in Geotrichum candidum.

The need to exercise care when identifying species of Geotrichum must be stressed, as this name has often been used erroneously to describe any hyaline hyphomycete producing arthroconidia . Geotrichum species may be differentiated from each other using physiological and biochemical tests similar to those used for the identification of yeasts.

MIC data is limited.  Antifungal susceptibility testing of individual strains is recommended.

Clinical significance:

Geotrichum candidum is an extremely common fungus with a world-wide distribution and is the causative agent of geotrichosis. Pulmonary involvement is the most frequently reported form of the disease, but bronchial, oral, vaginal, cutaneous and alimentary infections have also been reported.

Mycosis: Hyalohyphomycosis

Further reading:

Domsch, K.H., W. Gams, and T.H. Anderson. 1980. Compendium of soil fungi. Volume 1. Academic Press, London, UK