Abstract

The most pressing problem in clinical mycology is the need for an methods for the early diagnosis opportunistic candidiasis and cryptococcosis. This investigation will produce oligonucleotide sequences that are specific for the most significant fungal pathogens and evaluate their ability to amplify fungal DNA in clinical specimens to diagnose mycotic infection. In addition, the taxonomic relationships in medical fungi will be examined by comparative analysis of the ribosomal RNA genes (rDNA) and by surveying representative isolates of pathogenic fungi for phylogenetically informative sequence variations within the major ribosomal subunit RNAs (5.8S, 17S and 25S RNAs) and the internal transcribed spacer region (ITS). The methods will include reverse transcriptase sequencing of ribosomal RNA and dideoxy-sequencing of single stranded DNA templates that are amplified from genomic DNA using the polymerase chain reaction (PCR). Studies of restriction fragment length polymorphisms (RFLP) will also be undertaken to investigate these relationships. The results of the taxonomic survey will complement the application of DNA technology to the clinical identification of pathogenic fungi. Taxon-specific """"""""signature sequences"""""""" will be serve as probes and markers for the identification of pathogens, and the PCR will be used to amplify specific fungal genes in clinical specimens as a diagnostic tool for the rapid identification of fungi associated with human disease.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI028836-02
Application #
3143436
Study Section
Bacteriology and Mycology Subcommittee 2 (BM)
Project Start
1991-09-30
Project End
1994-07-31
Budget Start
1992-09-01
Budget End
1993-07-31
Support Year
2
Fiscal Year
1992
Total Cost
Indirect Cost

  Institution

Name
Duke University
Department
Type
Schools of Medicine
DUNS #
071723621
City
Durham
State
NC
Country
United States
Zip Code
27705

  Publications

Diezmann, Stephanie; Cox, Cymon J; Schonian, Gabriele et al. (2004) Phylogeny and evolution of medical species of Candida and related taxa: a multigenic analysis. J Clin Microbiol 42:5624-35
Xu, Jianping; Mitchell, Thomas G (2003) Geographical differences in human oral yeast flora. Clin Infect Dis 36:221-4
Luo, Guizhen; Mitchell, Thomas G (2002) Rapid identification of pathogenic fungi directly from cultures by using multiplex PCR. J Clin Microbiol 40:2860-5
Xu, J; Ramos, A R; Vilgalys, R et al. (2000) Clonal and spontaneous origins of fluconazole resistance in Candida albicans. J Clin Microbiol 38:1214-20
McEwen, J G; Taylor, J W; Carter, D et al. (2000) Molecular typing of pathogenic fungi. Med Mycol 38 Suppl 1:189-97
Pinto de Andrade, M; Schonian, G; Forche, A et al. (2000) Assessment of genetic relatedness of vaginal isolates of Candida albicans from different geographical origins. Int J Med Microbiol 290:97-104
Xu, J; Boyd, C M; Livingston, E et al. (1999) Species and genotypic diversities and similarities of pathogenic yeasts colonizing women. J Clin Microbiol 37:3835-43
Forche, A; Schonian, G; Graser, Y et al. (1999) Genetic structure of typical and atypical populations of Candida albicans from Africa. Fungal Genet Biol 28:107-25
Xu, J; Vilgalys, R; Mitchell, T G (1999) Lack of genetic differentiation between two geographically diverse samples of Candida albicans isolated from patients infected with human immunodeficiency virus. J Bacteriol 181:1369-73
Xu, J; Mitchell, T G; Vilgalys, R (1999) PCR-restriction fragment length polymorphism (RFLP) analyses reveal both extensive clonality and local genetic differences in Candida albicans. Mol Ecol 8:59-73

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