Clinical-mycologic diagnosis of oral yeast infections

Abstract

Conventional oral specimens for recovery of yeasts are swabs and smears. Oral rinses and imprint/impression cultures can also be used. Yeasts grow well at room temperature and may multiply in specimens under transport. Direct smears examined for blastospores, hyphae, and inflammatory cells ensure rapid presumptive diagnosis. Fungal identification requires culture, preferably on different media and at different temperatures to ensure recognition of all species present. YM agar supplemented with 0.01% aniline enables detection of Candida albicans and C. parapsilosis on primary plates through fluorescence. Microstix-Candida or Oricult-N slides can be read after culture at room temperature. Histologic sections for demonstration of yeasts require periodic acid-Schiff, Gridley, or Gomori's methenamine silver staining. Fungiqual staining enables non-specific diagnosis, also of rare oral mycoses, within 30min, through fluorescence. Calcofluor white is even faster (<30sec). Specific antibodies labeled with fluorescent stain enable more precise mycologic diagnosis. Mycologic findings should be interpreted together with clinical findings.