Coccidioides immitis

Ascomycota
Scientific classification
Kingdom:	Fungi
Division:	Ascomycota
Class:	Euascomycetes
Order:	Onygenales
Family:	Onygenaceae
Genus:	Coccidioides
Binomial name
Coccidioides immitis G.W. Stiles

Sputum culture of Coccidioides immitis on Sabouraud's medium, showing white, cottony fungus growth.

Coccidioides immitis is a pathogenic fungus that resides in the soil in certain parts of the southwestern United States, northern Mexico, and a few other areas in the Western Hemisphere.

It, along with its relative Coccidioides posadasii, is most commonly seen in the desert regions of the southwestern United States, and in Central and South America. It can cause a disease called coccidioidomycosis (Valley Fever). Coccidioidomycosis isn't diagnosed on the basis of signs and symptoms, which are usually vague and nonspecific, or on a chest X-ray, which can't distinguish valley fever from other lung diseases. For that reason, one or more of the following tests can be performed: SPUTUM SMEAR OR CULTURE: These tests check a sample of the sputum for the presence of coccidioides organisms. BLOOD TESTS: Through a blood test, a doctor can check for antibodies against the fungus that causes valley fever. It has been declared a select agent by both the U.S. Department of Health and Human Services and the U.S. Department of Agriculture, and is considered a biosafety level 3 pathogen.

In popular culture

Coccidioides immitis is used as a plot device in Thunderhead, a novel by Douglas Preston and Lincoln Child. The fungus (prepared from infected victims) is revealed to be the principal agent in corpse powder (based on corpse poison used by Witch). It was also mentioned by the fictional antihero Dr Gregory House (played by actor James Hugh Calum Laurie) on the Television Series, House MD (episode Lines in the Sand).

Microscopic appearance of an old culture of Coccidioides immitis, showing fragmented chlamydospores. This is the infective form of the fungus occurring in nature.

Septate hyphae of Coccidioides immitis with 90 degree branching and thick walled barrel shaped arthoconidia alternating with empty cells.