Coloured scanning electron micrograph (SEM) of hyphae from Candida albicans (green) fungus infecting a neutrophil white blood cell. When activated the granulocyte will destroy the yeast as part of the body's immune response. C. albicans is a dimorphic fungus. It may be either spherical, or form many thread-like hyphae. It is commonly found on the skin and the mucous membranes of the mouth, digestive and respiratory tracts and the vagina, where it is usually harmless. However, the use of antibiotics or a suppressed immune system can lead to infection. Common candida infections include oral thrush, vaginal thrush and nappy rash.