How Candida albicans switches phenotype - and back again: the SIR2 silencing gene has a say in Candida's colony type

Among the many bugs that live in the mouth and digestive tract is the yeast Candida albicans, which under normal circumstances lives in 80% of the human population with no harmful effects. However, overgrowth results in thrush, a condition often observed in immunocompromised individuals such as HIV-positive patients. Candidiasis also occurs in the blood and in the genital tract. 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. This switching between two cell types is known as dimorphism.