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.
Images library
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Title
Legend
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Necrotic lung tissue in culture
Af=Colony of Aspergillus fumigatus
B=bacterial colonies
L=lung tissue -
A photograph of part of the upper lung lobe of an immunosuppressed patient. The lung tissue shows extenive areas of necrosis due to invasive colonisation.
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A photograph of a cavity in the upper lobe of the lung of a patient with ankylosing spondylitis. Such cavitation,which may be confused with prior tuberculosis, can follow fibrosis.
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Plugs stained with Methenamine/silverActively growing mycelia of the fungus are a deep brown/black. Counterstaining shows the dense mucus of the plugs as predominantly orange.
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Sputum from an asthmatic patient showing plugs(casts). The development of plugs coincided with an increased prevalence and severity of episodes of asthma
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microscopic characters Conidiophore stipes(C)1300-2800um long:Vesicles(V)40-70um wide,clavate:Phialides(Ph) uniseriate:Conidia(Con)3.5-4.0um long,smooth walled.
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microscopic characters Conidiophore stipes(C)225-350um arising from hyphae(Hy):Vesicles(Ves)15-25um wide:Phialides(Ph)uniseriate:Conidia(Con)2.4-3.0um spherical to ovoid,roughened.