Candida tropicalis is a species of yeast in the Candida genus. It's a typical inhabitant of the human body and is not normally considered to be a health issue. However, a colony of Candida tropicalis can experience overgrowth under some conditions, causing an infection known as candidiasis.
Infections
The Candida genus contains about 150 species, but only six are generally able to cause candidiasis in humans. These include Candida albicans, Candida tropicalis, Candida glabrata, Candida parapsilosis, Candida krusei and Candida lusitaniae. Candida albicans is responsible for half of these cases, and Candida tropicalis is the second-most common cause of candidiasis, with 15 to 30 percent of all cases.
Occurrence
Candida tropicalis is typically found in human mucous membranes and is a common cause of disseminated candidiasis and septicemia. Varieties of Candida tropicalis that are unable to ferment sucrose (table sugar) are becoming increasingly more common causes of disseminated candidiasis. Candida tropicalis can also be found in the environment in feces, shrimp and soil.
Appearance
Candida tropicalis grows readily on Sabouraud's dextrose agar. These colonies will have a smooth appearance and will be white-to-cream in color. A microscopic examination of Candida tropicalis should show typical yeast cells that are generally spherical. These cells range from 3 to 5.5 micrometers (um) in width and 4 to 9um in length.
Assimilation
Microorganisms such as yeast are frequently classified according to the substances they're able to ferment. Candida tropicalis is typically able to ferment sugars such as galactose, glucose, maltose and trehalose. It's generally unable to ferment sugars such as lactose, melibiose and raffinose. Some varieties of Candida tropicalis can ferment sugars such as cellobiose, melezitose and sucrose.
Minimum Inhibitory Concentration
The minimum inhibitory concentration (MIC) is the minimum concentration of an antifungal agent that will inhibit the growth of a fungus. The MIC90 level is the concentration needed to kill 90 percent of a colony. The MIC90 value of Candida tropicalis is 2 micrograms per milliliter (ug/ml) for fluconazole, 0.5 ug/ml for amphotericin B and 0.125 for flucytosine.
