Use of a suspension array for rapid identification of the varieties and genotypes of the Cryptococcus neoformans species complex

Mara Diaz, Jack W. Fell

Research output: Contribution to journalArticle

55 Citations (Scopus)

Abstract

Cryptococcus neoformans is an encapsulated fungal pathogen known to cause severe disease in immunocompromised patients. The disease, cryptococcosis, is mostly acquired by inhalation and can result in a chronic meningoencephalitis, which can be fatal. Here, we describe a molecular method to identify the varieties and genotypic groups within the C. neoformans species complex from culture-based assays. The method employs a novel flow cytometer with a dual laser system that allows the simultaneous detection of different target sequences in a multiplex and high-throughput format. The assay uses a liquid suspension hybridization format with specific oligonucleotide probes that are covalently bound to the surface of fluorescent color-coded microspheres. Biotinylated target amplicons, which hybridized to their complementary probe sequences, are quantified by the addition of the conjugate, streptavidin R-phycoerythrin. In this study we developed and validated eight probes derived from sequence analysis of the intergenic spacer region of the rRNA gene region. The assay proved to be specific and sensitive, allowed discrimination of a 1-bp mismatch with no apparent cross-reactivity, and detected 101 to 103 genome copies. The described protocol, which can be used directly with yeast cells or isolated DNA, can be undertaken in less than 1 h following PCR amplification and permits identification of species in a multiplex format. In addition to a multiplex capability, the assay allows the simultaneous detection of target sequences in a single reaction. The accuracy, speed, flexibility, and sensitivity of this technology are a few of the advantages that will make this assay useful for the diagnosis of human cryptococcal infections and other pathogenic diseases.

Original languageEnglish (US)
Pages (from-to)3662-3672
Number of pages11
JournalJournal of Clinical Microbiology
Volume43
Issue number8
DOIs
StatePublished - Aug 2005

Fingerprint

Cryptococcus neoformans
Suspensions
Genotype
Phycoerythrin
Cryptococcosis
Meningoencephalitis
Intergenic DNA
Streptavidin
Oligonucleotide Probes
Immunocompromised Host
Microspheres
rRNA Genes
Inhalation
Sequence Analysis
Lasers
Color
Yeasts
Genome
Technology
Polymerase Chain Reaction

ASJC Scopus subject areas

  • Microbiology
  • Microbiology (medical)

Cite this

Use of a suspension array for rapid identification of the varieties and genotypes of the Cryptococcus neoformans species complex. / Diaz, Mara; Fell, Jack W.

In: Journal of Clinical Microbiology, Vol. 43, No. 8, 08.2005, p. 3662-3672.

Research output: Contribution to journalArticle

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