Magnusiomyces clavatus

Synonmy: 
Saprochaeta clavata, Geotrichum clavatum.

Saprochaete clavata (formerly known as Geotrichum clavatum), which is also closely related to Magnusiomyces capitatus (formerly known as Geotrichum capitatum or Saprochaeta capitata), has only very infrequently been described as involved in invasive human infection.

However, an outbreak of invasive infections caused by Saprochaete clavata in haematology patients has been reported (Vaux et al. 2013).

RG-1 organism.

Morphological description:
Colonies are moderately fast growing, flat, whitish and butyrous. True hyphae are abundant, soon breaking up into rectangular arthroconidia of variable size, 2.8-4 3 x 6-20 μm. Sympodial conidiogenesis is occasionally present. Terminal parts of hyphae may swell and become thick-walled.

Note: Saprochaete clavata and Magnusiomyces capitatus are human pathogens that are closely related and are frequently mistaken for each other.

Molecular identification:
ITS sequencing is recommended for accurate species identification.

MALDI-TOF MS: 
Reliably identifies S. clavata, M. capitatus and Geotrichum candidum to the species level (Desnos-Ollivier et al. 2014).

References: 
de Hoog and Smith (2004, 2011b), de Hoog et al. (2015), Desnos-Ollivier et al. (2014), Vaux et al. (2013), Arendrup et al. (2014).

Physiological Tests: + Positive, - Negative, v Variable, w Weak, s Slow, nd No Data
Germ Tube - L-Sorbose + L-Arabinose - D-Glucitol -
Fermentation   Sucrose - D-Arabinose - 𝝰-M-D-glucoside -
Glucose - Maltose - D-Ribose - D-Gluconate -
Galactose - Cellobiose + L-Rhamnose - DL-Lactate +,w
Sucrose - Trehalose - D-Glucosamine - myo-Inositol -
Maltose - Lactose - NAD-glucosamine nd 2-K-D-Gluconate -
Lactose - Melibiose - Glycerol + D-Glucuronate nd
Trehalose - Raffinose - Erythritol - Nitrate -
Assimilation   Melezitose - Ribitol - Urease -
Glucose + Soluble Starch - Galactitol - 0.1% Cycloheximide -
Galactose + D-Xylose - D-Mannitol - Growth at 40C +

Antifungal susceptibility: Saprochaete clavata (Geotrichum clavatum) very limited data (1); MIC µg/mL.  
Note: S. claveta reported to be intrinsically resistant to echinocandins .

  No 0.016 0.03 0.06 0.125 0.25 0.5 1 2 4 ≥8
AmB 4         1 1 1 1    
VORI 3     1   1 1        
POSA 3           2 1      
ITRA 4         2 2        
5FC 4     2 1   1        

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