Cross-sectional study of oral Candida carriage in a human immunodeficiency virus (HIV)-seropositive population: predisposing factors, epidemiology and antifungal susceptibility

The Candida species isolated from oral rinses of 130 human immunodeficiency virus (HIV) infected patients were compared with those of 130 healthy non-matched volunteers. The oral rinses were plated on CHROMagar Candida medium (CAC) and on CAC supplemented with 10 micrograms (CF10) and 100 micrograms (CF100) of fluconazole per ml. The prevalence of non-albicans Candida spp. in oral rinses of HIV-infected patients and their correlation with the clinical and epidemiological characteristics of the patients were studied. Susceptibility of the Candida spp. isolated was determined by a microbroth dilution method based on the NCCLS reference procedure. Results of susceptibility tests of the yeast isolates were compared with their growth at the time of isolation on CAC supplemented with fluconazole. Thirty-five (30.7%) strains of non-albicans Candida spp. were isolated from the HIV-positive population, vs. seven (15.9%) from the immunocompetent population. Growth on CF10 correlated in 96% of the cases with fluconazole minimum inhibitory concentration (MIC) > 8 micrograms ml-1. Smoking and use of azoles were significantly associated with oral carriage of non-albicans Candida spp. (P < 0.05). The prevalence of non-albicans Candida spp. in HIV-positive persons in oral rinse samples is twice as high as in the HIV-negative population. Smoking and treatment with azoles are risk factors for the oral carriage of non-albicans Candida spp. The isolation of yeasts on CAC plates supplemented with fluconazole allows combination of presumptive yeast identification and fluconazole susceptibility testing.