Azole-resistant Candida albicans: report of two cases of resistance to fluconazole and review.

We report the course of oropharyngeal infection by Candida albicans that was refractory to treatment with fluconazole in two patients infected by the human immunodeficiency virus (HIV). We also review the epidemiology of C. albicans with decreased in vitro and in vivo susceptibility to azole antifungal agents, the significance of such isolates, the known mechanisms by which C. albicans may become less susceptible to azole antifungal agents, and the efficacy of various treatments for mucosal candidiasis. The occurrence in HIV-infected patients of mucosal candidiasis that is refractory to therapy with fluconazole and is due to C. albicans that demonstrates decreased in vitro susceptibility to fluconazole has been reported since 1990. Following the release of miconazole and ketoconazole in the late 1970s, C. albicans with decreased in vitro susceptibility to these agents was isolated from patients with chronic mucocutaneous candidiasis who required repeated and prolonged courses of therapy. Subsequently, C. albicans with decreased in vitro-susceptibility to ketoconazole, clotrimazole, and itraconazole has been isolated from HIV-infected patients. Recent reports of the sexual and nosocomial transmission of wild-type C. albicans indicate the possibility of future person-to-person transmission of C. albicans with decreased in vitro susceptibility to azole antifungal agents.