PCR fingerprinting: a convenient molecular tool to distinguish between Candida dubliniensis and Candida albicans

Candida dubliniensis was recently identified as a germ-tube- and chlamydosp ore-positive yeast, phenotypically and morphologically indistinguishable fr om the phylogenetically closely related yeast species C. albicans and its s ynonymized variant C. stellatoidea. The high similarity between these yeast species causes significant problems in the correct identification of C. du bliniensis in a standard clinical mycology laboratory, Polymerase chain rea ction (PCR) fingerprinting was successfully applied here to distinguish bet ween clinical isolates of the two closely related species. Microsatellite ( [GACA](4)) and minisatellite ([5'-GAGGGTGGCGGTTCT-3'], derived from the cor e-sequence of the wild-type phage M13) specific oligonucleotides were used as single primers in PCR to amplify hypervariable inter-repeat DNA sequence s from 16 C. dubliniensis strains and 11 C, albicans strains. Each species, represented by its ex-type strain, could be identified by a distinct speci es-specific multilocus pattern, allowing identification to species level fo r all clinical isolates. In addition, the PCR fingerprinting generated stra in-specific profiles, making this method applicable to epidemiological inve stigations. PCR fingerprinting using the primer M13 is proposed here as a s imple, reliable and highly reproducible molecular tool to differentiate bet ween strains of C. albicans and C, dubliniensis.