An HIV positive female has an indurated ulcer over the tongue. Laboratory findings show growth in cornmeal agar at 20 degrees, microscopy showing hyphae and growth inhuman serum at 37 degrees show budding yeasts. The probable cause is:

Ans. (a) Candida albicans Ref. Harrison 19/e, p 1342, 18/e, p 1652 "This is a case of oral thrush secondary to candidiasis" C. albicans is a dimorphic fungi which occur both as yeast and moulds (with hyphae). In HIV oral thrush occurs when CD4 <50/1.11.