A Comparison of the Ability of Fungal Internal Transcribed Spacers and D1/D2 Domain Regions to Accurately Identify Candida glabrata Clinical Isolates Using Sequence Analysis

Abstract

Candida glabrata is the second most prevalent causative agent for candidiasis following C. albicans. The opportunistic yeast, C. glabrata, is able to cause the critical bloodstream infections in hospitalized patients. Conventional identification methods for yeasts are often time consuming and labor intensive. Therefore, recent studies on sequence-based identification have been conducted. Recently, sequencing the D1/D2 domain of the large subunit ribosomal RNA gene and the internal transcribed spacers (ITS) 1 and ITS2 regions of the ribosomal DNA has proven useful for DNA-based identification of most species of fungi. In the present study, therefore, fungal ITS and D1/D2 domain regions were targeted and analyzed by DNA sequencing for the accurate identification of C. glabrata clinical isolates. A total of 102 C. glabrata clinical isolates from various clinical samples including bloodstream, catheterized urine, bile and other body fluids were used in the study. The results of the DNA sequence analysis showed that the mean standard deviation of species identity percent score between ITS and D1/D2 domain regions was 97.8% ± 2.9 and 99.7% ± 0.46, respectively. These results revealed that the D1/D2 domain region might be a better target for identifying C. glabrata clinical isolates based on DNA sequences than the ITS1 and ITS2 regions. However, in order to evaluate the usefulness of D1/D2 domain region for species identification of all Candida species, other Candida species such as C. albicans, C. tropicalis, C. dubliniensis, and C. krusei should be verified in further studies additionally.

New Fungal Strains from Peat Soil in Malaysia: Morphological and Molecular Characteristics

“…Molecular analysis based on the D1/D2 of the 28S rRNA sequence was used to confirm the identification of fungi. Many studies have stated that sequencing of the D1/D2 region is the recognised gold standard for fungal identification [54]. However, the morphological findings and molecular data were compared to ensure consistency and identification of the fungus strains in the current work.…”