Microsporum canis

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Scientific classification
Kingdom: Fungi
Phylum: Ascomycota
Class: Euascomycetes
Order: Onygenales
Family: Arthrodermataceae
Genus: Microsporum
Species: canis
Binomial name
Microsporum canis

Description and significance

Microsporum canis is a fungus also known as a dermatophyte that causes dermatophytosis (ringworm) in canines and felines. They are commonly found in humid, warm climates. Although canines and felines are its natural reservoir it can cause ringworm in humans.

Genome structure

Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence? Does it have any plasmids? Are they important to the organism's lifestyle?

Cell structure and metabolism

Microscopically this species has multicelled macroconidia (spores) with thick, rough walls. They are barreled shaped with an asymmetrical apical knob and are 6 to 15 cells long. When grown on a culture medium for at least 4 days colonies produce a white cottony surface with yellow around the periphery and the underside is bright yellow or orange. (2) This organism gains energy from keratin found in nails, hair and skin. It secretes keratinolytic protease, which provides the fungus with nutrients by degrading keratin into easily assimilable metabolites. This secreted protease also allows the invasion of keratinized structures and controls the host defense mechanisms. (4)

Ecology

Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.

Pathology

This fungal pathogen causes ringworm mainly in cats and dogs, but is a common source for human infection. This fungus can be picked up by direct contact with other infected animals or by contact with spores that have contaminated objects such as grooming equipment, furniture and the environment. Spores are very resistant without treatment and can live up to two years infecting animals and humans. Spores will attach to the skin and germinate producing hyphae, which will then grow in the dead, superficial layers of the skin, hair or nails. The most investigated virulence factors has been keratinolytic protease. The secretion of this protease causes some damage to the skin and hair follicle. The skin will have a hypersensitive reaction becoming inflamed causing the fungus to move away from the site to normal skin. This creates characteristic circular lesions with healing at the center and inflammation at the edge. (3) Some cats can be asymptomatic while others will exhibit flacky skin, hair lose and occasionally inflamed skin. Cats that are less than a year old, long haired or have a comprised immune system are more susceptible to ringworm. A reason for younger cats susceptibility to this fungus can be that their immune system is immature and its defense mechanisms are limited to infection. Long haired cats are easier targets for infection because their grooming is less efficient and self grooming is an effective way of removing spores from the skin and fur. Their long hair also protects the dermatophytes from sun exposure which they can not tolerate. The infection is primarily found on ears head or extremity of the paws. Dogs will exhibit non-inflammatory flaky skin with hair lose.


Application to Biotechnology

Does this organism produce any useful compounds or enzymes? What are they and how are they used?

Current Research

Enter summaries of the most recent research here--at least three required

References

1) http://www.fabcats.org/owners/skin/ringworm.html

2) http://www.doctorfungus.org/thefungi/microsporum_canis.htm
3)http://www.vetstreamfelis.com/ACI/January08/VMD1/bug00270.asp 

4)http://www.nature.com/jid/journal/v119/n4/full/5601629a.html#bib23