Aspergillus fumigatus

Date: 7 May 2013

Copyright: n/a

Notes:

Colonies on CYA 40-60 mm diam, 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. Colonies on MEA 40-60 mm diam, similar to those on CYA but less dense and with conidia in duller colours (24-25E-F3); reverse uncoloured or greyish. Colonies on G25N less than 10 mm diam, sometimes only germination, of white mycelium. No growth at 5°C. 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.

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.

Distinctive features

This distinctive species can be recognised in the unopened Petri dish by its broad, velutinous, bluish colonies bearing characteristic, well defined columns of conidia. Growth at 37°C is exceptionally rapid. 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.


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Showing 10 posts of 2574 posts found.
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  • Medium power view of lung (H&E) in which there is invasion of lung parenchyma by hyphae characteristic of Aspergillus resulting in lung tissue infarction.

    patt3

  • Vascular thrombosis. Medium power view (H&E) of a blood vessel occluded by fungal hyphae and thrombosis. Some fungal hyphae can be seen traversing the vessel wall.

    Vascular thrombosis

  • Four colonies of Aspergillus on an agar plate containing rose bengal (to limit colony spending) and elastin fibres (light pink dots). Underneath and surrounding the colonies, the elastin fibres have gone, indicating enzymatic degradation

    patt19

  • High power view of elastin fibres in an arterial wall being forced apart by Aspergillus hyphae. As Aspergillus is angiotropic and produces an elastase, it was uncertain how it traversed vessel walls. It appears to do so without any dissolution of elastin fibres.

    patt18

  • Medium power view (GMS) of hyphae seen within an arterial wall which is characteristic of angioinvasive Aspergillus.

    patt17

  • High power view (H&E) of a branching mould, consistent with Aspergillus inside a giant cell in a patient with chronic granulomatous disease.

    patt15

  • High power view (GMS) of an Aspergillus hypha within a giant cell in a patient with chronic granulomatous disease infected with Aspergillus.

    patt14

  • High power view (Papanicolau) of hyphae identified in sputum.

    patt13

  • Medium power view (GMS) of the contents of a cerebral abscess in which there are hyphae typical of Aspergillus. Aspergillus fumigatus was grown from adjacent tissue.

    patt10

  • Low power view (H&E) showing a pulmonary vein and a small bronchus infiltrated by fungal hyphae with associated necrotising inflammation.

    patt1