Submitted to: American Society for Microbiology Meeting
Publication Type: Abstract Only
Publication Acceptance Date: May 27, 2004
Publication Date: N/A
Technical Abstract: Yeast infections are particularly devastating in AIDS and other immuno-compromised patients and treatment for a given infection can vary between species. An efficient DNA-based assay would be particularly beneficial for rapid identification of infective species. We have developed a system of DNA probes using the Luminex 100 flow cytometer that identifies nearly 30 medically important ascomycetous yeasts. The bead-based assays are designed for multiplexing so that all medically important ascomycetous yeast species can be detected in a single well. Domains D1/D2 of the large subunit (26S) ribosomal DNA were used for probe design because this rDNA region has been sequenced for all known species, shows little sequence variation between strains of a species, but contains enough variation among different species to design effective probes. We present a comparison of FlexMap technology with the DNA Direct Hybridization method to assess the strengths of each method. Both methods correctly distinguished between closely related species such as Candida albicans, C. dubliniensis, C. tropicalis, C. sojae, C. maltosa, C. parapsilosis, and C. lodderae, as well as the more distantly related C. glabrata, and Pichia (Candida) guilliermondii. The FlexMap method required fewer probe redesigns, and was better able to distinguish single nucleotide differences between species. The Direct Hybridization method required fewer steps to complete and used fewer resources. Both methods represent an accurate DNA-based assay that will distinguish between medically important ascomycetous yeasts in as little as 5 hours.