Saccharomyces cerevisiae is a colonizer of mucosal surfaces and is part of the normal flora of the gastrointestinal tract, the respiratory tract, and the vagina. The most important disease caused by S. cerevisiae is fungemia. It occurs in immunocompromised and critically ill patients. Saccharomyces infection is clinically indistinguishable from invasive candidiasis. Fever is common and chorioretinitis may occur.
The yeast is characterized by round to oval multilateral budding yeast cells and short, rudimentary pseudohyphae.