Oral candidiasis (also known as "thrush") is an infection of yeast fungi of the genus Candida on the mucous membranes of the mouth. It is frequently caused by Candida albicans, or less commonly by Candida glabrata or Candida tropicalis. Oral thrush may refer to candidiasis in the mouths of babies, while if occurring in the mouth or throat of adults it may also be termed candidosis or moniliasis.