Oral Candida dubliniensis as a clinically important species in HIV-seropositive patients in the United States

Objective. Interest in Candida dubliniensis has led to renewed clinical inv estigations regarding incidence, drug resistance, pathogenesis, and epidemi ology of fungal infections in patients with HIV. C dubliniensis phenotypica lly resembles Candida albicans in many respects, yet it can be identified a nd differentiated as a unique Candida species by its phenotypic and genetic profiles. The purpose of this study was to prospectively evaluate the prev alence of C dubliniensis in clinical isolates and determine the clinical an d demographic characteristics of patients harboring C dubliniensis. Study design. Over a 6-week period, 24 yeast-positive isolates from HIV-pos itive dental patients were screened for C dubliniensis through use of pheno typic criteria. HIV viral load, CD4 count, and complete oral health evaluat ions were performed on each patient at the same visit during which the oral fungal surveillance culture was taken. Results. Six isolates from 24 HIV-seropositive and yeast-positive patients were shown to be consistent phenotypically and by electrophoretic karyotypi ng with the European reference strain of C dubliniensis. Dose-dependent sus ceptibility to fluconazole was shown in one of the C dubliniensis isolates. Five of the 6 patients demonstrated moderate to high viral loads. General oral health, as evidenced by the presence of advanced periodontal lesions a nd a high decayed, missing, and filled teeth index (>20), was poor in 3 of the 6 patients with C dubliniensis and 7 of the 18 patients with C albicans . A history of intravenous drug abuse was present in 50% of the C dublinien sis-positive patients, which is representative of the HIV-positive populati on at the hospital. Conclusions. In this small sample, C dubliniensis represented 25% of the ye ast-positive cultures. The clinical significance of this interesting specie s in the United States may be related to high viral load, rapid AIDS progre ssion, and/or concomitant oral disease, such as a high caries index or peri odontal disease.