Schizophyllum commune is a common basidiomycete bracket fungus found on rotten wood, and is an occasional human pathogen, principally associated with sinusitis, allergic bronchopulmonary mycosis and as a contaminant from respiratory specimens. However the introduction of DNA sequencing and/or MALDI-TOF MS identification in the clinical laboratory has seen many more cases of S. commune fungal rhinosinusitis identified (Michel et al. 2012, Chowdhary et al. 2013a, 2014a,b).
Morphological Description: Colonies on 2% malt extract agar are spreading, woolly, whitish to pale greyish-brown, soon forming macroscopically visible fruiting bodies. Some isolates may take up to 12 weeks to form fruiting bodies. Fruit bodies are sessile, kidney-shaped, lobed with split gills on the lower side. Hyphae are hyaline, wide and have clamp connections. Basidia bear four basidiospores on erect sterigmata. Basidiospores hyaline, smooth-walled, elongate with lateral scar at lower end, 6-7 x 2-3 µm.
Note: Many clinical isolates of S. commune are monokaryotic and do not show clamp connections, therefore any white, rapidly growing, sterile isolate showing good growth at 37C with tolerance to benomyl, susceptibility to cycloheximide, and a pronounced odour should be suspected of being S. commune (Sigler et al. 1995).
Molecular Identification: Sequencing of the ITS and D1/D2 regions is recommended (Buzina et al. 2001, Won et al. 2012, Chowdhary et al. 2013b, Michel et al. 2012), however the number of well identified nucleotide sequences of these fungi in the GenBank database remains limited.
MALDI-TOF MS: Michel et al. (2012), Chowdhary et al. (2014b), Huguenin et al. (2015) provide identification procedures, however the number of mass spectral profiles to be found in MALDI-TOF libraries remains limited.
References: McGinnis (1980), Rippon (1988), Sigler et al. (1995), de Hoog et al. (2015).
Basidiocarps of Schizophyllum commune on malt extract agar.