DESCRIPTIONS OF MEDICAL FUNGI

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Descriptions of Medical Fungi
Nannizzia gypsea (Nannizzi) Stockdale
Synonymy: Microsporum gypseum (Bodin) Guiart & Grigorakis.
Nannizzia gypsea is a geophilic fungus with a worldwide distribution which may cause
infections in animals and humans, particularly children and rural workers during warm
humid weather. Usually produces a single inflammatory skin or scalp lesion. Invaded
hairs show an ectothrix infection but do not fluoresce under Wood’s ultra-violet light.
RG-1 organism.
Morphological Description: Colonies are usually flat, spreading, suede-like to
granular, with a deep cream to tawny-buff to pale cinnamon-coloured surface. Many
cultures develop a central white downy umbo (dome) or a fluffy white tuft of mycelium
and some also have a narrow white peripheral border. A yellow-brown pigment, often
with a central darker brown spot, is usually produced on the reverse, however a reddishbrown
reverse pigment may be present in some strains. Cultures produce abundant,
symmetrical, ellipsoidal, thin-walled, verrucose, four to six-celled macroconidia. The
terminal or distal ends of most macroconidia are slightly rounded, while the proximal
ends (point of attachment to hyphae) are truncate. Numerous clavate-shaped
microconidia are also present, but these are not diagnostic.
Key Features: Distinctive macroconidia and culture characteristics.
Molecular Identification: ITS sequencing is recommended, especially for the
separation of N. gypsea and N. incurvata which are morphologically similar.
References: Rebell and Taplin (1970), Rippon (1988), Gräser et al. (2008), Cafarchia
et al. (2013), de Hoog et al. (2015, 2016).
a
b
20 µm
Nannizzia gypsea (a) culture and (b) macroconidia.