Objective: The objectives of this study were to evaluate the clinical presentation(s) of oral candidiasis, Candida species abundance and antifungal drug susceptibility in APECED patients.
Methods: Sixteen APECED patients (age range 2-29 years) and 16 age- and gender-matched healthy controls underwent a comprehensive medical, dental, and drug history, followed by a clinical and microbiological evaluation of oral candidiasis. Clinical examination and oral sampling were undertaken on three separate occasions over a six month period. Candida isolates recovered from oral rinse samples were presumptively identified based on colony colour following culture on CHROMagar Candida medium and subsequently definitively identified with the API ID 32C system. Antifungal drug susceptibility testing was preformed by broth microdilution and by E-test.
Results: 11/16 (68.8%) of the APECED patients exhibited clinical signs indicative of candidiasis, whereas 13/16 (81.3%) were oral Candida carriers, of whom 7/13 (53.8%) demonstrated microbiological evidence of candidiasis (i.e. ≥500 Candida cfu/ml oral rinse). Candida carriage/infection was transient among the cohort over the six month period. Surprisingly C. albicans was the only Candida species identified. Three patients (19%) harboured strains that were resistant to fluconazole (MIC range 64-128 µg/ml) and itraconazole (MIC range 2-16 µg/ml).
Conclusions: Oral candidiasis with C. albicans is a significant but transient feature of APECED. Protracted antifungal use has lead to the selection of resistant isolates in some patients. Surprisingly, non-C. albicans species were not recovered, in stark contrast to many other patient groups with recurrent oral candidiasis.