Identification for medically important yeast-like fungal species by sequence analysis of 18S rRNA gene

Abstract

Objective To compare sequence analysis of the yeast-like fungal isolates with traditional methods and analyze the feasibility of identification of common yeast-like fungal by sequence analysis of gene. Methods 115 yeast-like fungal isolates were collected in the clinical laboratory of Beijing Tongren Hospital. DNA of yeast-like fungal was extracted and then amplified with universal primers of part of 18S rRNA genes followed by sequencing directly. The sequences obtained were submitted to the GenBank (NCBI) to identify the fungi. At the same time, the CHROMagar Candida and Vitek 32 YBC were used to identify the fungi. The identification accuracy with three methods was compared to explore the feasibility of the identification of sequence analysis. Results 18S rRNA gene sequence analysis was compared with traditional method. There were some differences in the identification results of 13 strains. The coincidence rate between CHROMagar Candida and sequence analysis was 89. 2% (91/102) and the coincidence rate between Vitek 32 YBC and sequence analysis was 91.3% (105/115). The positivity rate of species-level identification by CHROMagar Candida , Vitek 32 YBC and the 18S rRNA gene sequence analysis were 88. 7 % ( 102/115 ), 100% ( 115/115 ), 100% ( 115/115 ). Conclusion Identification of medically important yeast-like fungal by sequence analysis of the 18S rRNA gene is reliability. Key words: Yeasts; RNA,ribosomal,18S; Sequence analysis,RNA