DESCRIPTIONS OF MEDICAL FUNGI

8
Descriptions of Medical Fungi
Apophysomyces complex
Comment: Apophysomyces complex is readily distinguished from other zygomycetes,
especially the morphologically similar, strongly apophysate pathogen Lichtheimia
corymbifera, by having sporangiophores with distinctive funnel or bell-shaped
apophyses and hemispherical-shaped columellae. In addition, there is a conspicuous
pigmented subapical thickening, which constricts the lumen of the sporangiophore
below the apophysis, and distinctive foot cells.
Laboratory identification of this fungus may be difficult or delayed because of the mould’s
failure to sporulate on primary isolation media or on subsequent subculture onto potato
dextrose agar. Sporulation may be stimulated by the use of nutrient deficient media,
like cornmeal-glucose-sucrose-yeast extract agar, Czapek Dox agar, or by using the
agar block method described by Ellis and Ajello (1982) and Ellis and Kaminski (1985).
Molecular-based identification is particularly helpful for the definitive identification of
poorly sporulating cultures.
Key Features: Soil fungus with a tropical to subtropical distribution. Characteristic
“cocktail glass” apophysate sporangial morphology with conspicuous subapical
thickening of the sporangiophore. Resistance to cycloheximide. Rapid growth at 42 O C,
no growth at 50 O C.
References: Misra et al. (1979), Ellis and Ajello (1982), Padhye and Ajello (1988),
Wieden et al. (1985), Lawrence et al. (1986), Cooter et al. (1990), Holland (1997), de
Hoog et al. (2000, 2015), Ellis (2005b), Alvarez et al. (2010a), Chakrabarti et al. (2003,
2010), Guarro et al. (2011).
Antifungal Susceptibility: A. variabilis limited data (Espinel-Ingroff et al. 2015a,
and Australian National data); MIC µg/mL.
No 64
AmB 10 1 1 3 5
POSA 10 1 1 7 1
A. variabilis data from 20 isolates (Alvarez et al. 2010 and Chakrabarti et al. 2010);
MIC µg/mL.
AmB Range 0.5-4; MIC 90
= 2 VORI Range 8-16; MIC 90
= 16
ITRA Range 0.25-2; MIC 90
= 2 POSA Range 0.5-2; MIC 90
= 1