title: Comparative analyses of classical phenotypic method and ribosomal RNA gene sequencing for identification of medically relevant Candida species.
abstract: As the distribution of Candida species and their susceptibility to antifungal agents have changed, a new means of accurately and rapidly identifying these species is necessary for the successful early resolution of infection and the subsequent reduction of morbidity and mortality. The current work aimed to evaluate ribosomal RNA gene sequencing for the identification of medically relevant Candida species in comparison with a standard phenotypic method. Eighteen reference strains (RSs), 69 phenotypically identified isolates and 20 inconclusively identified isolates were examined. Internal transcribed spaces (ITSs) and D1/D2 of the 26S ribosomal RNA gene regions were used as targets for sequencing. Additionally, the sequences of the ITS regions were used to establish evolutionary relationships. The sequencing of the ITS regions was successful for 88% (94/107) of the RS and isolates, whereas 100% of the remaining 12% (13/107) of the samples were successfully analysed by sequencing the D1/D2 region. Similarly, genotypic analysis identified all of the RS and isolates, including the 20 isolates that were not phenotypically identified. Phenotypic analysis, however, misidentified 10% (7/69) of the isolates. Phylogenetic analysis allowed the confirmation of the relationships between evolutionarily close species. Currently, the use of genotypic methods is necessary for the correct identification of Candida species.
authors.affiliation: Departamento Micología, Instituto Nacional de Enfermedades Infecciosas Dr Carlos G Malbrán, Buenos Aires, Argentina. ctaverna@anlis.gov.ar
authors.forename: Constanza Giselle
authors.initials: CG
authors.lastname: Taverna
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Bosco-Borgeat
authors.forename: Omar Alejandro
authors.initials: OA
authors.lastname: Murisengo
authors.forename: Graciela
authors.initials: G
authors.lastname: Davel
authors.forename: Mariana Côrtes
authors.initials: MC
authors.lastname: Boité
authors.forename: Elisa
authors.initials: E
authors.lastname: Cupolillo
authors.forename: Cristina Elena
authors.initials: CE
authors.lastname: Canteros
mesh_terms: D002175:Candida / Q000145:classification / Q000235:genetics*; D004271:DNA, Fungal / Q000032:analysis*; D021903:DNA, Ribosomal Spacer / Q000235:genetics*; D020459:Genes, rRNA / Q000235:genetics*; D005838:Genotype; D006801:Humans; D010641:Phenotype; D016133:Polymerase Chain Reaction; D017423:Sequence Analysis, RNA
chemical_list: D004271:DNA, Fungal; D021903:DNA, Ribosomal Spacer