YEAST PANEL multiplex PCR for identification of clinically important yeast species: stepwise diagnostic strategy, useful for developing countries.

Identification of opportunistic yeasts in developing countries is mainly performed by phenotypic assays, which are time-consuming and prone to errors. Wrong species identification may result in suboptimal treatment and inaccurate epidemiological data. To improve rapidity and accuracy of species identification, a diagnostic strategy using a stepwise "YEAST PANEL multiplex PCR assays" targeting 21 clinically important yeast species of Candida, Trichosporon, Rhodotorula, Cryptococcus, and Geotrichum was designed. Four hundred CBS reference strains were used for optimization and specificity testing. Eight hundred clinical species were prepared in blinded sets for multiplex polymerase chain reaction (PCR) and matrix-assisted laser desorption time of flight mass spectrophotometry (MALDI-TOF MS) investigation. Results obtained from YEAST PANEL multiplex PCR assay were 100% consistent with those of MALDI-TOF MS. Utilization of pure colony testing showed distinct amplicons for each species, thus eliminating the need for DNA extraction. The targeted yeast species of this assay are responsible for 95% of the yeast infections. In conclusion, due to the high accuracy and coverage of a broad range of yeasts, this assay could be useful for identification in routine laboratories and epidemiological studies.