A real-time PCR assay for the differentiation of Candida species

Aims: We established a real-time PCR assay for the detection and strain identification of Candida species and demonstrated the ability to differentiate between Candida albicans the most common species, and also Candida parapsilosis, Candida glabrata, Candida tropicalis and Candida dubliniensis by LightCycler PCR and melting curve analysis. Methods and Results: The DNA isolation from cultures and serum was established using the QIAmp Tissue Kit. The sensitivity of the assay was >/= 2 genome equivalents/assay. It was possible to differentiate all investigated Candida species by melting curve analysis, and no cross-reaction to human DNA or Aspergillus species could be observed. Conclusions: The established real-time PCR assay is a useful tool for the rapid identification of Candida species and a base technology for more complex PCR assays. Significance and Impact of the Study: We carried out initial steps in validation of a PCR assay for the detection and differentiation of medically relevant Candida species. The PCR was improved by generating PCR standards, additional generation of melting curves for species identification and the possibility to investigate different specimens simultaneously.