Candida bracarensis detected among isolates of Candida glabrata by peptide nucleic acid fluorescence in situ hybridization: susceptibility data and documentation of presumed infection

J Clin Microbiol. 2008 Feb;46(2):443-6. doi: 10.1128/JCM.01986-07. Epub 2007 Dec 12.

Abstract

Molecular taxonomic studies have revealed new Candida species among phenotypically delineated species, the best example being Candida dubliniensis. This study was designed to determine the occurrence of two new molecularly defined species, Candida bracarensis and Candida nivariensis, which are closely related to and identified as Candida glabrata by phenotypic assays. A total of 137 recent clinical isolates of C. glabrata identified by phenotypic characteristics was tested with C. bracarensis and C. nivariensis species-specific peptide nucleic acid fluorescence in situ hybridization probes. Three of 137 (2.2%) isolates were positive with the C. bracarensis probe, whereas the control strain, but none of the clinical isolates, was positive with the C. nivariensis probe. D1/D2 sequencing confirmed the identification of the three isolates as representing C. bracarensis. Clinically, one C. bracarensis isolate was recovered from a presumed infection, a polymicrobial pelvic abscess in a patient with perforated diverticulitis. The other two isolates were recovered from two adult oncology patients who were only colonized. C. bracarensis was white on CHROMagar Candida, had variable API-20C patterns that overlapped with C. nivariensis and some C. glabrata isolates, and had variable results with a rapid trehalose assay. Interestingly, an isolate from one of the colonized oncology patients was resistant to fluconazole, itraconazole, voriconazole, and posaconazole in vitro. In summary, C. bracarensis was detected among clinical isolates of C. glabrata, while C. nivariensis was not. One C. bracarensis isolate causing a presumed deep infection was recovered, and another isolate was azole resistant. Whether clinical laboratories should identify C. bracarensis will require more data.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Candida / classification*
  • Candida / drug effects
  • Candida / genetics
  • Candida / isolation & purification*
  • Candidiasis / microbiology*
  • Carrier State / microbiology
  • DNA, Fungal / chemistry
  • DNA, Fungal / genetics
  • DNA, Ribosomal / chemistry
  • DNA, Ribosomal / genetics
  • Female
  • Genes, rRNA
  • Humans
  • In Situ Hybridization, Fluorescence / methods*
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Mycological Typing Techniques
  • Pelvic Infection / microbiology
  • Peptide Nucleic Acids* / genetics
  • Phylogeny
  • RNA, Fungal / genetics
  • RNA, Ribosomal / genetics
  • Sequence Analysis, DNA

Substances

  • DNA, Fungal
  • DNA, Ribosomal
  • Peptide Nucleic Acids
  • RNA, Fungal
  • RNA, Ribosomal
  • RNA, ribosomal, 26S