High-throughput detection of pathogenic yeasts of the genus trichosporon

J Clin Microbiol. 2004 Aug;42(8):3696-706. doi: 10.1128/JCM.42.8.3696-3706.2004.

Abstract

The need for a rapid and accurate method for the detection of fungal pathogens has become imperative as the incidence of fungal infections has increased dramatically. Herein, we tested the Luminex 100, a novel flow cytometer, for the detection of the medically important genus Trichosporon. This genus was selected as our proof-of-concept model due to the close phylogenetic relationship between the species. The method, which is based on a nucleotide hybridization assay, consists of a combination of different sets of fluorescent beads covalently bound to species-specific capture probes. Upon hybridization, the beads bearing the target amplicons are classified by their spectral addresses with a 635-nm laser. Quantitation of the hybridized biotinylated amplicon is based on fluorescence detection with a 532-nm laser. We tested in various multiplex formats 48 species-specific and group-specific capture probes designed in the D1/D2 region of ribosomal DNA, internal transcribed spacer regions, and intergenic spacer region. Species-specific biotinylated amplicons were generated with three sets of primers to yield fragments from the three regions. The assay was specific and fast, as it discriminated species differing by 1 nucleotide and required less than 50 min following amplification to process a 96-well plate. The sensitivity of the assay allowed the detection of 10(2) genome molecules in PCRs and 10(7) to 10(8) molecules of biotinylated amplification product. This technology provided a rapid means of detection of Trichosporon species with the flexibility to identify species in a multiplex format by combining different sets of beads.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • Cells, Cultured
  • DNA Primers
  • DNA, Fungal / isolation & purification
  • Humans
  • Mycoses / diagnosis*
  • Nucleic Acid Hybridization
  • Phylogeny
  • Polymerase Chain Reaction
  • Trichosporon / classification
  • Trichosporon / genetics
  • Trichosporon / isolation & purification
  • Trichosporon / pathogenicity*

Substances

  • DNA Primers
  • DNA, Fungal