Aspergillus fumigatus

Entry in species database

Case histories:

– ptMB-2

– ptJO-2

This distinctive species can be recognised in the unopened Petri dish by its broad, velutinous, bluish colonies bearing characteristic, well defined columns of conidia. Conidial heads are also diagnostic: pyriform vesicles bear crowded phialides which bend to be roughly parallel to the stipe axis. Care should be exercised in handling cultures of this species.

 

Appearance of colonies

CYA:   40-60 mm diameter, plane or lightly wrinkled, low, dense and velutinous or with a sparse, floccose overgrowth; mycelium inconspicuous, white; conidial heads borne in a continuous, densely packed layer, Greyish Turquoise to Dark Turquoise (24-25E-F5); clear exudate sometimes produced in small amounts; reverse pale or greenish.

MEA:   40-60 mm diameter, similar to those on CYA but less dense and with conidia in duller colours (24-25E-F3); reverse uncoloured or greyish.

G25N:   less than 10 mm diam, sometimes only germination, of white mycelium.

 

Appearance of conidia

Conidiophores borne from surface hyphae, stipes 200-400 µm long, sometimes sinuous, with colourless, thin, smooth walls, enlarging gradually into pyriform vesicles; vesicles 20-30 µm diam, fertile over half or more of the enlarged area, bearing phialides only, the lateral ones characteristically bent so that the tips are approximately parallel to the stipe axis; phialides crowded, 6-8 µm long; conidia spherical to subspheroidal, 2.5-3.0 µm diam, with finely roughened or spinose walls, forming radiate heads at first, then well defined columns of conidia.

 

Temperature and growth

No growth at 5°C.

Growth at 37°C is exceptionally rapid. At 37°C, colonies covering the available area, i.e. a whole Petri dish in 2 days from a single point inoculum, of similar appearance to those on CYA at 25°C, but with conidial columns longer and conidia darker, greenish grey to pure grey.


Our sponsors