Current Fungal Infection Reports

, Volume 6, Issue 3, pp 170–177 | Cite as

Recent Taxonomic Developments with Candida and Other Opportunistic Yeasts

  • Mary E. BrandtEmail author
  • Shawn R. Lockhart
Clinical Lab Issues (M Pfaller, Section Editor)


Increases in susceptible patient populations and advances in identification methods have resulted in the continued recognition of novel yeasts as agents of human infection. Most of these agents are members of the well-recognized genera Candida, Cryptococcus, Trichosporon, and Rhodotorula. Some of these agents are “cryptic species,” members of species complexes, and may not be detectable using classical carbohydrate assimilation-based methods of yeast identification. Such species require DNA- or MALDI-based methods for correct identification, although sporadic isolates may not routinely require delineation to the individual species level. The coming end of the fungal taxonomy rules requiring separate names for sexual and asexual forms of the same fungus will hopefully allow greater clarity, as names for medically important yeast can now be based on the needs of the medical mycology community and the common goal of better communication between laboratory and clinician.


Non-albicans Candida Candida species Cryptococcus species Trichosporon species Emerging fungal infections Antifungal resistance Yeast infection 



The findings and conclusions in this presentation/report are those of the author(s) and do not necessarily represent the official position of the Centers for Disease Control and Prevention.


No potential conflicts of interest relevant to this article were reported.


Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance

  1. 1.
    van Belkum A, et al. Biomedical mass spectrometry in today’s and tomorrow’s clinical microbiology laboratory. J Clin Microbiol. 2012;50:1513–7.PubMedCrossRefGoogle Scholar
  2. 2.
    •• Taylor JW, et al. Phylogenetic species recognition and species concepts in fungi. Fungal Genet Biol. 2000;31:21–32. This paper describes the rationale behind the concept of a phylogenetic species.PubMedCrossRefGoogle Scholar
  3. 3.
    Hawksworth DL. Pandora’s mycological box: molecular sequences vs. morphology in understanding fungal relationships and biodiversity. Rev Iberoam Micol. 2006;23:127–33.PubMedCrossRefGoogle Scholar
  4. 4.
    • Clinical and Laboratory Standards Institute. MM18-A: Interpretive criteria for identification of bacteria and fungi by DNA target sequencing; Approved Guideline. Wayne: CLSI; 2007. Lists the DNA targets currently used to identify most common fungal species. Google Scholar
  5. 5.
    ••Hawksworth DL. Managing and coping with names of pleomorphic fungi in a period of transition. Mycosphere. 2012;3:52–64. Explains the rationale behind the end of the “one fungus-two names” taxonomic rule.CrossRefGoogle Scholar
  6. 6.
    Miceli MH, Diaz JA, Lee SA. Emerging opportunistic yeast infections. Lancet Infect Dis. 2011;11:142–51.PubMedCrossRefGoogle Scholar
  7. 7.
    Schmid J, et al. Increased mortality in young candidemia patients associated with presence of a Candida albicans general-purpose genotype. J Clin Microbiol. 2011;49:3250–6.PubMedCrossRefGoogle Scholar
  8. 8.
    Ells R, Kock JLF, Pohl CH. Candida albicans or Candida dubliniensis? Mycoses. 2011;54:1–16.PubMedCrossRefGoogle Scholar
  9. 9.
    Lockhart SR. Do hospital microbiology laboratories still need to distinguish Candida albicans from Candida dubliniensis? J Clin Microbiol. 2011;49:4415.PubMedCrossRefGoogle Scholar
  10. 10.
    Romeo O, Criseo G. Candida africana and its closest relatives. Mycoses. 2011;54:475–86.PubMedCrossRefGoogle Scholar
  11. 11.
    Falagas ME, Roussos N, Vardakas KZ. Relative frequency of albicans and the various non-albicans Candida species among candidemia isolates form inpatients in various parts of the world: a systematic review. Int J Infect Dis. 2010;14:e954–66.PubMedCrossRefGoogle Scholar
  12. 12.
    Warren TA, et al. Candida bracarensis bloodstream infection in an immunocompromised patient. J Clin Microbiol. 2010;48:4677–9.PubMedCrossRefGoogle Scholar
  13. 13.
    Yang YL, et al. Comparison of human and soil Candida tropicalis isolates with reduced susceptibility to fluconazole. Plos One. 2012;7:e34609.PubMedCrossRefGoogle Scholar
  14. 14.
    •• Kurtzman CP, Fell JW, Boekhout T, editors. The yeasts: a taxonomic study. 5th ed. London: Elsevier; 2011. The standard manual for yeast taxonomy and identification.Google Scholar
  15. 15.
    Savini V, et al. What do we know about Candida guilliermondii? A voyage throughout past and current literature about this emerging yeast. Mycoses. 2011;54:434–41.PubMedCrossRefGoogle Scholar
  16. 16.
    Jensen RH, Arendrup MC. Candida palmioleophila: characterization of a previously overlooked pathogen and its unique susceptibility profile in comparison with five related species. J Clin Microbiol. 2011;49:549–56.PubMedCrossRefGoogle Scholar
  17. 17.
    Paredes K, et al. Molecular identification and antifungal susceptibility of clinical isolates of Candida rugosa species complex and proposal of the new species Candida neorugosa. J Clin Microbiol. 2012. doi: 10.1128/JCM.00688-12.
  18. 18.
    Taverna CG, et al. First case report of bloodstream infection due to a Candida species closely related to the novel species Candida pseudorugosa. J Clin Microbiol. 2012;50:2165–9.PubMedCrossRefGoogle Scholar
  19. 19.
    Kurtzman CP. Phylogeny of the ascomycetous yeasts and the renaming of Pichia anomala to Wickerhamomyces anomalus. Antonie van Leeuwenhoek. 2011;99:13–23.PubMedCrossRefGoogle Scholar
  20. 20.
    Al-Sweih N, et al. Kodamaea ohmeri as an emerging pathogen: a case report and review of the literature. Med Mycol. 2011;49:766–70.PubMedGoogle Scholar
  21. 21.
    Pfüller R, et al. A novel flucytosine-resistant yeast species, Candida pseudoaaseri, causes disease in a cancer patient. J Clin Microbiol. 2011;49:4195–202.PubMedCrossRefGoogle Scholar
  22. 22.
    Adam H, et al. Identification of a new species, Candida subhashii, as a cause of peritonitis. Med Mycol. 2009;47:305–11.PubMedCrossRefGoogle Scholar
  23. 23.
    Lee WG, et al. First three reported cases of nosocomial fungemia caused by Candida auris. J Clin Microbiol. 2011;49:3139–42.PubMedCrossRefGoogle Scholar
  24. 24.
    Bovers M, Hagen F, Boekhout T. Diversity of the Cryptococcus neoformans-Cryptococcus gattii species complex. Rev Iberoam Micol. 2008;25:S4–S12.PubMedCrossRefGoogle Scholar
  25. 25.
    Kwon-Chung KJ, Polacheck I, Bennett JE. Improved diagnostic medium for separation of Cryptococcus neoformans var. neoformans (serotypes A and D) and Cryptococcus neoformans var. gattii (serotypes B and C). J Clin Microbiol. 1982;15:535–7.PubMedGoogle Scholar
  26. 26.
    • McTaggart L, et al. Rapid identification of Cryptococcus neoformans var. grubii, C. neoformans var. neoformans, and C. gattii by use of rapid biochemical tests, differential media, and DNA sequencing. J Clin Microbiol. 2011;49:2522–7. A very helpful description of the most recent ways to separate these two species.PubMedCrossRefGoogle Scholar
  27. 27.
    Meyer W, et al. Consensus multi-locus typing scheme for Cryptococcus neoformans and Cryptococcus gattii. Med Mycol. 2009;47:561–70.PubMedCrossRefGoogle Scholar
  28. 28.
    Ngamskulrungroj F, et al. Genetic diversity of the Cryptococcus species complex suggests that Cryptococcus gattii deserves to have varieties. PLoS One. 2009;4:e5862.PubMedCrossRefGoogle Scholar
  29. 29.
    Byrnes EJ, et al. Cryptococcus gattii: an emerging fungal pathogen infecting humans and animals. Microbes Infect. 2011;13:895–907.PubMedCrossRefGoogle Scholar
  30. 30.
    • Harris J, et al. Cryptococcus gattii in the United States: clinical aspects of infection with an emerging pathogen. Clin Infect Dis. 2011;53:1188–95. Describes clinical aspects of patients diagnosed with C. gattii infection.PubMedCrossRefGoogle Scholar
  31. 31.
    Iqbal N, et al. Correlation of genotype and in vitro susceptibilities of Cryptococcus gattii strains from the Pacific Northwest of the United States. J Clin Microbiol. 2010;48:539–44.PubMedCrossRefGoogle Scholar
  32. 32.
    Lockhart SR, et al. Epidemiologic cutoff values for triazole drugs in Cryptococcus gattii: correlation of molecular type and in vitro susceptibility. Diagn Microbiol Infect Dis. 2012. doi: 10.1016/j.diagmicrobio.2012.02.018.
  33. 33.
    Chagas-Neto TC, Chaves GM, Colombo AL. Update on the genus Trichosporon. Mycopathologia. 2008;166:121–32.PubMedCrossRefGoogle Scholar
  34. 34.
    Hickey PW, et al. Trichosporon mycotoxinivorans, a novel respiratory pathogen in patients with cystic fibrosis. J Clin Microbiol. 2009;47:3091–7.PubMedCrossRefGoogle Scholar
  35. 35.
    Chitasombat MN, et al. Rare opportunistic (non-Candida, non-Cryptococcus) yeast bloodstream infections in patients with cancer. J Infect. 2012;64:68–75.PubMedCrossRefGoogle Scholar
  36. 36.
    Gaitanis G, et al. The Malassezia genus in skin and systemic diseases. Clin Microbiol Rev. 2012;25:106–41.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC (outside the USA) 2012

Authors and Affiliations

  1. 1.Mycotic Diseases BranchCenters for Disease Control and PreventionAtlantaUSA

Personalised recommendations