Fluconazole sensitivities of Candida species isolated from the mouths of terminally ill cancer patients

Abstract

Oral candidosis is common in advanced cancer and is often treated with the systemic triazole antifungal drug fluconazole. This study examined the species of yeast present in the mouths of 30 patients with advanced cancer and determined their sensitivity to fluconazole. Thirty-five yeast isolates were collected from a total of 25 (83 percent) of the patients sampled. The two most common species were Candida albicans (15 isolates) and C. glabrata (11 isolates)—with smaller numbers of C. tropicalis, C. parapsilosis, C. guilliermondii, C. inconspicua, and Saccharomyces cerevisiae. The minimal inhibitory concentrations (MIC) of fluconazole for the strains of C. albicans were generally low (median 0.19µg/ml) but were considerably higher for C. glabrata (median 2µg/ml). The remaining species demonstrated MICs similar to those for C. albicans, with the exceptions of C. inconspicua and Saccharomyces cerevisiae, which were relatively insensitive. In conclusion, non-albicans yeasts are common in the mouths of patients with advanced cancer and these may have reduced sensitivity to fluconazole. Mycological diagnosis is a valuable aid to management.