Induced palatal candidosis in the Wistar rat

Palatal candidosis was induced by inoculating Candida albicans 3091 (serotype A) under an acrylic appliance. After 1 week, the palatal epithelium showed acute inflammatory cell infiltration and surface colonization by blastospores. Two weeks after inoculation, the inflammation had increased, micro-abscesses were observed and fungal hyphae penetrated the keratin layer. After 4 weeks, these changes were further intensified and the epithelium was markedly hyperplastic. Six weeks after inoculation, some areas of the epithelium were atrophic and others markedly hyperplastic, with fungal hyphal penetration. The histological changes in the epithelium were dependent on the presence of the palatal acrylic plate. When the appliance was removed 4 weeks after inoculation, the epithelial changes resolved within a further 2 weeks. Microbiological sampling of the mucosal surface revealed, however, that the organisms persisted.