Aspergillus fumigatus

Aspergillus fumigatus is a heat-tolerant fungus that is common in soil and fruits and occasionally causes human infections. Aspergillus fumigatus is also heat-tolerant and found worldwide. A. fumigatus it is particularly dense in agricultural soils but is commonly isolated from house dust, garbage, compost, potted plants, humidifiers and HVAC systems, as well. More importantly, A. fumigatus is isolated commonly from human patients. In healthy humans, A. fumigatus is not a pathogen. However, this species can cause severe infections in humans with suppressed immune systems (e.g. those with preexisting illnesses or taking immunosuppressants). In such individuals, spores that are inhaled are not attacked efficiently by the host’s immune system, and the spores could germinate and begin to invade host tissues.