Light micrograph of yeast culture, probably Candida parapsilosis. Candida species are part of the normal flora of mucous membranes of the mouth, gut and vagina. They are opportunistic fungi which may grow and become invasive if the host is immunologically compromised; steroid therapy, malnutrition, diabetes and antibiotic suppression of the normal bacterial flora are predisposing factors. Thrush is a very common infection usually caused by Candida albicans, although as with other fungal infections of the skin and mucous membranes other species such as C. parapsilosis may be responsible. Magnification: x787 at 35mm size.