Oral candidiasis: a comparison between conventional methods and multiplex polymerase chain reaction for species identification.

Oral candidiasis is the most common fungal infection in dental practice, and is caused by yeasts that are normally present in the endogenous flora. METHODS: To evaluate a rapid diagnostic method for identification of Candida oral isolates, a multiplex polymerase chain reaction (PCR) was carried out on colonies and on oral rinse solutions from 95 subjects with suspected oral candidiasis and results were compared with those from seven commonly used phenotypic identification systems. RESULTS: Between four and nine species were characterized in the samples by the phenotypic methods. PCR identified the same species in 60 (74%) samples from both colony and oral rinse solutions. Statistical analysis, carried out only for the three most frequently isolated species (Candida albicans, Candida glabrata, and Candida tropicalis), showed good concordance in the comparison of multiplex PCR with API 20C AUX and with the Rapid Yeast Identification Panel; conversely, significant differences were registered in the comparison between the molecular method and other phenotypic systems, including four chromogenic media and the automated system Vitek2. DISCUSSION: Multiplex PCR was rapid and effective in the identification of Candida species and allowed the detection of more than one species in the same sample.