Candida albicans is a diploid fungus that grows both as yeast and filamentous cells and a causal agent of opportunistic oral and genital infections in humans.
Everyone has Candida, and a significant proportion of us may have Candidiasis, or an overgrowth of Candida. Candida starts to cause trouble when there is some change in your body that allows it to overgrow. This change could be anything from a few courses of antibiotics, a prolonged diet rich in carbohydrates and sugar, or even something as common as a lengthy period of stress at work.
Systemic fungal infections (fungemias) including those by C. albicans have emerged as important causes of morbidity and mortality in immunocompromised patients (e.g., AIDS, cancer chemotherapy, organ or bone marrow transplantation).
C. albicans is commensal and a constituent of the normal gut flora comprising microorganisms that live in the human mouth and gastrointestinal tract.
C. albicans lives in 80% of the human population without causing harmful effects, although overgrowth of the fungus results in candidiasis (candidosis).
Candidiasis is often observed in immunocompromised individuals such as HIV-infected patients. A common form of candidiasis restricted to the mucosal membranes in mouth or vagina is thrush, which is usually easily cured in people who are not immunocompromised. For example, higher prevalence of colonization of C. albicans was reported in young individuals with tongue piercing, in comparison to non-tongue-pierced matched individuals.
To infect host tissue, the usual unicellular yeast-like form of C. albicans reacts to environmental cues and switches into an invasive, multicellular filamentous form, a phenomenon called dimorphism.