Date: 26 November 2013
Plugs cultured on agarA young colony of the fungus(AF) has a central patch of sporulation and is surrounded by colonies of bacteria and yeasts.
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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The chest x-ray shows a patient who had a left lung transplanted in May 2003 for cryptogenic fibrosing alveolitis, which was diagnosed post-transplant as sarcoidosis.
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Gross pathology demonstrating the great pleural thickness and two cavities (upper lobe and superior segment of lower lobe) with fragments of fungal mass.
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Histopathological appearance of a fungus ball. Note a conidial head resulting from fungal exposure to the air.
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Histopathological appearance of a fungus ball caused by Scedosporium apiospermum. The presence of anneloconidia differentiates it from Aspergillus.
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Chronic necrotising aspergillosis. Hyaline hyphal and calcium oxalate crystals obtained by needle aspirate biopsy from a diabetic patient with chronic necrotizing aspergillosis caused by Aspergillus niger (Papanicolaou, x 100).
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Aspergillus niger fungus ball and acute oxalosis. Higher magnification of adjacent replicate section.
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Oxalate crystals within renal tubuli (H&E, phase contrast, x 100). This patient developed acute oxalosis.
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Lung surface. Fungus ball, severe parenchymal fibrosis and pleural thickening.