Candida albicans. Colored Scanning Electron Micrograph (SEM) of the fungus Candida albicans, cause of human thrush. At lower center, rounded yeast-like spores are seen of different sizes. These spores have produced filaments (hyphae) which spread into a fungal network (mycelium) and produce more spores. Candida albicans causes the infection known as candidiasis. This affects moist mucous membranes of the body, such as skin folds, mouth, respiratory tract and vagina. Oral and vaginal conditions are known as thrush. Genital thrush is sexually transmitted. The infection may also appear in persons receiving prolonged broad spectrum antibiotics, or in diabetics.