Candida dubliniensis and Candida albicans differentiation by colony morphotype in Sabouraud-triphenyltetrazolium agar.

BACKGROUND Candida dubliniensis is a germ tube and chlamydoconidia producing Candida species that may be misidentified as Candida albicans. Molecular-based methods are the most reliable techniques for C. albicans and C. dubliniensis differentiation. However, accurate, quick and inexpensive phenotypic tests are needed to be used in low-complexity mycology laboratories. AIMS To evaluate colony morphotypes on Sabouraud-triphenyltetrazolium agar as a tool for C. dubliniensis and C. albicans differentiation. METHODS The morphology of 126 C. albicans and C. dubliniensis strains was evaluated and compared with their identification by molecular methods. RESULTS The method showed 100% sensitivity and specificity when color and the presence or absence of large white mycelial halo was evaluated. CONCLUSIONS Colony morphotype on Sabouraud-triphenyltetrazolium agar should be considered as a new tool to differentiate C. dubliniensis and C. albicans.