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.
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Diagnosis: Aspergilloma with invasive aspergillosis evidence of invasion found in the lumbar spine and brain, in addition to heart.
Fungal endocarditis with NO evidence of bacterial endocarditismia.Additional image details:
A. Normal chest X ray:
This (normal) chest X-ray was taken about 6 weeks before endocarditis was diagnosed, and 3 months before death due to disseminated aspergillosis. No CT scan was done (a chest radiograph has a 10% false negative rate in leukaemic patients, compared with CT).B. Aspergillus niger Fungal ball:
Gross section of lung at autopsy showing a discrete, well-demarcated dark/black mass surrounded by a fibrotic capsule. There was no evidence of local invasion, or infarction. The patient had had acute myeloid leukaemia (M1) and responded poorly to chemotherapy. He developed A.niger endocarditis and disseminated disease to the kidneys, lumbar disc and heart, probably arisiong from this lesion. It is unclear whether this lung lesion was a partially cured ‘mycotic lung sequestrum’ following antifungal therapy, or originated as an aspergilloma. The confirmation of genus and species was obtained by PCR on blood and vegetations.C. Endocarditis:
Macroscopic view of the heart at autopsy, showing an infracted lesion on the papillary muscle of the mitral valve in the left ventricle. In addition the patient had large vegetations, which are not shown here. The confirmation of genus and species was obtained by PCR on blood and vegetations; the pericarditis was a manifestation of disseminated aspergillosis.D. Pericarditis due to Aspergillus niger:
Macroscopic view of the pericardium at autopsy, showing gross chronic haemorrhagic pericarditis. The confirmation of genus and species was obtained by PCR on blood and vegetations; the pericarditis was a manifestation of disseminated aspergillosis.E. Lumbar discitis:
Macroscopic lesion of a lumbar intervertebral vertebral at autopsy, showing haemorrhagic necrosis, caused by hyphal invasion and infarction. The confirmation of genus and species was obtained by PCR on blood and vegetations; the discitis was a manifestation of disseminated aspergillosis.
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Secondary metabolites, structure diagram: Trivial name – Folipastatin
