Internal transcribed spacer sequencing versus biochemical profiling for identification of medically important yeasts.
In this study, we established an in-house database of yeast internal transcribed spacer (ITS) sequences. This database includes medically important as well as colonizing yeasts that frequently occur in the diagnostic laboratory. In a prospective study, we compared molecular identification with phenotypic identification by using the ID32C system (bioMérieux) for yeast strains that could not be identified by a combination of CHROMagar Candida and morphology on rice agar. In total, 113 yeast strains were included in the study. By sequence analysis, 98% of all strains were identified correctly to the species level. With the ID32C, 87% of all strains were identified correctly to the species or genus level, 7% of the isolates could not be identified, and 6% of the isolates were misidentified, most of them as Candida rugosa or Candida utilis. For a diagnostic algorithm, we suggest a three-step procedure which integrates morphological criteria, biochemical investigation, and sequence analysis of the ITS region.
Ciardo
D E
DE
Institut für Medizinische Mikrobiologie, Universität Zürich, Switzerland.
Schär
G
G
Böttger
E C
EC
Altwegg
M
M
Bosshard
P P
PP
D002176:Candida albicans / Q000145:classification / Q000235:genetics; D002177:Candidiasis / Q000175:diagnosis* / Q000382:microbiology; D004271:DNA, Fungal / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000032:analysis*; D030541:Databases, Genetic; D006801:Humans; D008828:Microbiological Techniques; D010802:Phylogeny; D011446:Prospective Studies; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic; D015003:Yeasts / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer