Date: 26 November 2013
cultures grown from BAL fluid showing formation of sclerotia.
Copyright:
Kindly donated by Dr Claudia Venturelli and Dr Giorgia Bertazzoni, Laboratory of Microbiology – Policlinico of Modena-Italy. © Fungal Research Trust
Notes:
These colonies were isolated from a BAL, (also with bacterial qrowth of S.aureus and S.maltophilia) from a patient with a VAP (undergoing corticosteroid treatment). The growth medium used is sabouraud dextrose agar , incubated at 37° C The identification is made by microscopic/macroscopic observation criteria.
Colonies on CYA 60-70 mm diam, plane, sparse to moderately dense, velutinous in marginal areas at least, often floccose centrally, sometimes deeply so; mycelium only conspicuous in floccose areas, white; conidial heads usually borne uniformly over the whole colony, but sparse or absent in areas of floccose growth or sclerotial production, characteristically Greyish Green to Olive Yellow (1-2B-E5-7), but sometimes pure Yellow (2-3A7-8), becoming greenish in age; sclerotia produced by about 50% of isolates, at first white, becoming deep reddish brown, density varying from inconspicuous to dominating colony appearance and almost entirely suppressing conidial production; exudate sometimes produced, clear, or reddish brown near sclerotia; reverse uncoloured or brown to reddish brown beneath sclerotia. Colonies on MEA 50-70 mm diam, similar to those on CYA although usually less dense. Colonies on G25N 25-40 mm diam, similar to those on CYA or more deeply floccose and with little conidial production, reverse pale to orange or salmon. No growth at 5°C. At 37°C, colonies usually 55-65 mm diam, similar to those on CYA at 25°C, but more velutinous, with olive conidia, and sometimes with more abundant sclerotia.
Sclerotia produced by some isolates, at first white, rapidly becoming hard and reddish brown to black, spherical, usually 400- 800 µm diam. Teleomorph not known. Conidiophores borne from subsurface or surface hyphae, stipes 400 µm to 1 mm or more long, colourless or pale brown, rough walled; vesicles spherical, 20-45 µm diam, fertile over three quarters of the surface, typically bearing both metulae and phialides, but in some isolates a proportion or even a majority of heads with phialides alone; metulae and phialides of similar size, 7-10 µm long; conidia spherical to subspheroidal, usually 3.5-5.0 µm diam, with relatively thin walls, finely roughened or, rarely, smooth.
Distinctive features
Aspergillus flavus is distinguished by rapid growth at both 25°C and 37°C, and a bright yellow green (or less commonly yellow) conidial colour. A. flavus produces conidia which are rather variable in shape and size, have relatively thin walls, and range from smooth to moderately rough, the majority being finely rough.
Images library
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Pt FT. Autopsy appearance of the trachea, after the adherent pseudomembrane had been removed, revealing confluent ulceration superiorly with small green plaques of Aspergillus growth on the trachea inferiorly.
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This view was obtained in a lung transplant recipient at bronchoscopy. Aspergillus fumigatus was grown from bronchial lavage but invasion was not demonstrated on bronchial biopsy. Symptoms improved with itraconazole therapy and abnormal appearances had resolved within 2 weeks.
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Bronchoscopic view of Aspergillus tracheobronchitis. Bronchial lavage revealed hyphae in microscopy and cultures grew A.fumigatus. This man had received a lung transplant a few weeks before. Invasion of mucosa, but not cartilage, was demonstrated histologically. He responded rapidly to oral itraconazole.
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This view from indirect laryngoscopy illustrates bilateral lesions on the larynx that on biopsy were shown to be due to Aspergillus. This is a rare disease in non-immunocompromised patients.
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Bronchoscopic view of a deep bronchial ulcer in a lung transplant patient. Biopsies through the ulcer yielded cartilage with hyphae invading it. Fungal cultures of bronchial lavage grew Aspergillus fumigatus. He responded to oral itraconazole therapy.
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Patient had life threatening pneumonia, cavity formation was later observed. He later presented with a fungal ball. The aspergilloma was removed by surgical resection of the right upper lobe.
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