Azole-resistant Candida spp. - emerging pathogens?

Invasive fungal infections cause significant morbidity and mortality in immunocompromised patients. Azoles, and fluconazole in particular, are very active against Candida albicans, and are used widely because of their good tolerability. However, the increasing use of azole antifungals for the treatment of mucosal and systemic Candida infections has resulted in the selection and/or emergence of resistant Candida strains. The main mechanisms of azole resistance among Candida species are the development of bypass pathways, alterations in the ERG 11 gene encoding the azole target enzyme, and the up-regulation of genes encoding efflux pumps. A better understanding of the mechanisms and clinical impact of antifungal resistance is essential to prompt and efficient treatment of patients with invasive mycoses and to improve the outcome of such infections.