Eukaryotes Genomes - ASPERGILLUS FUMIGATUS

Aspergillus is a filamentous, cosmopolitan and ubiquitous fungus. It is commonly isolated from soil, plant debris, and indoor air environments particularly moist kitchens and bathrooms. The genus Aspergillus includes over 185 species. Around 20 species have so far been reported as causative agents of opportunistic infections in man. Among these, Aspergillus fumigatus is the most commonly isolated species.

On agar, colonies show typical blue-green surface pigmentation with a suede-like surface consisting of a dense felt of conidiophores (An asexually produced fungal spore). Conidial heads are typically columnar (up to 400 x 50 um but often much shorter and smaller) and arranged in one row. Conidiophores are short, smooth-walled and have conical-shaped terminal vesicles which support a single row of phialides on the upper two thirds of the vesicle. Conidia are produced in basipetal succession forming long chains and are globose to subglobose (2.5-3.0 um in diameter), green and rough-walled. Aspergillus spp. is thermotolerant and grows at temperatures up to 55C. A teleomorphic state has been described only for some of the Aspergillus spp. and others are accepted to be mitosporic, without any known sexual spore production.

Four percent of all patients dying in tertiary care hospitals in Europe have invasive aspergillosis. The fungus causes allergic deseases in asthmatics and patients suffering from cystic fibrosis. Invasive aspergillosis can occur in individuals with cavities caused by tuberculosis or other cystic lung diseases. Almost any organ or system in the human body may be involved. Onychomycosis, sinusitis, cerebral aspergillosis, meningitis, endocarditis, myocarditis, pulmonary aspergillosis, osteomyelitis, otomycosis, endophthalmitis, cutaneous aspergillosis, hepatosplenic aspergillosis, as well as Aspergillus fungemia, and disseminated aspergillosis may develop. Nosocomial occurrence of aspergillosis due to catheters and other devices is also likely.

Aspergillus spp. may also be local colonizers in previously developed lung cavities due to tuberculosis, sarcoidosis, bronchiectasis, pneumoconiosis, ankylosing spondylitis or neoplasms, presenting as a distinct clinical entity, called aspergilloma. Aspergilloma may also occur in kidneys.

Aspergillus spp. can cause infections in animals as well as in man. In birds, respiratory infections may develop and it may induce mycotic abortion in cattle and the sheep. Ingestion of high amounts of aflatoxin may induce lethal effects in poultry animals fed with grain contaminated with the toxin.

References:

http://www.aspergillus.man.ac.uk/
http://www.doctorfungus.org/thefungi/Aspergillus_spp.htm
http://www.sanger.ac.uk/Projects/A_fumigatus/
http://www.mycology.adelaide.edu.au/Fungal_Descriptions/Hyphomycetes_(hyaline)/Aspergillus/fumigatus.html
http://www.moldbacteria.com/myblog/2005_05_01_moldbacteria_archive.html