-nora-

Reservoirs of medically important fungi are found in animals, humans and soils. The classification of medically important fungi is based on morphology, namely, filamentous fungi, yeast and dimorphic fungi

1. Aspergillus

Description and Natural Habitats

Aspergillus is a filamentous, cosmopolitan and ubiquitous fungus found in nature. It is commonly isolated from soil, plant debris, and indoor air environment. While a teleomorphic state has been described only for some of the Aspergillus spp., others are accepted to be mitosporic, without any known sexual spore production.

Species

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, followed by Aspergillus flavus and Aspergillus niger. Aspergillus clavatus, Aspergillus glaucus group, Aspergillus nidulans, Aspergillus oryzae, Aspergillus terreus, Aspergillus ustus, and Aspergillus versicolor are among the other species less commonly isolated as opportunistic pathogens. See the list of obsolete names and synonyms for older names of these species.

The color of the colony in various Aspergillus species


2. Malassezia furfur

Description and Natural Habitats

Malassezia is a lipophilic yeast found on skin and body surfaces of humans and animals. It has been shown that colonization with Malassezia may occur as early as neonatal period [794]. It is a member of the normal skin flora in as much as 90% of adults and may occasionally cause superficial and deep mycoses. Malassezia has no known teleomorphic phase.
Species

There are seven proposed species in the genus Malassezia based on molecular, morphological, and biochemical profiles [277, 929, 953, 1369, 2087, 2407]. The most common and well-known species are Malassezia furfur and Malassezia pachydermatis [1223]. See the complete list of active species and summary of synonyms for the Malassezia spp.

In humans, the species causing skin disease, including the most common cause of dandruff and tinea versicolor is Malassezia furfur. The skin rash of tinea versicolor (pityriasis versicolor) is due to infection by this fungi, and is also thought to be involved in the skin condition of seborrhoeic dermatitis.
As the fungus requires fat to grow, it is most common in areas with many sebaceous glands: on the scalp, face, and upper part of the body. When the fungus grows too rapidly, the natural renewal of cells is disturbed and dandruff appears with itching (a similar process may also occur with other fungi or bacteria).


Feferences
1. Doctor Fungus. Retrieved on-line: http://www.doctorfungus.org/thefungi/malassezia_furfur.htm
2. Wikipedia. Retrieved on-line: http://en.wikipedia.org/wiki/Malassezia_furfur