Systematic Internal Transcribed Spacer Sequence Analysis for Identification of Clinical Mold Isolates in Diagnostic Mycology: a 5-Year Study

• Published in: Journal of Clinical Microbiology 2010-08, Vol.48 (8), p.2809-2813
• Main Authors: Ciardo, Diana E, Lucke, Katja, Imhof, Alex, Bloemberg, Guido V, Böttger, Erik C
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; DNA, Fungal - chemistry; DNA, Fungal - genetics; DNA, Ribosomal Spacer - chemistry; DNA, Ribosomal Spacer - genetics; Fundamental and applied biological sciences. Psychology; Fungi - classification; Fungi - genetics; Fungi - isolation & purification; Humans; Microbiology; Mycological Typing Techniques - methods; Mycology; Mycology - methods; Mycoses - diagnosis; Mycoses - microbiology; Sensitivity and Specificity; Sequence Analysis - methods
• ISSN: 0095-1137; 1098-660X
• DOI: 10.1128/JCM.00289-10

The implementation of internal transcribed spacer (ITS) sequencing for routine identification of molds in the diagnostic mycology laboratory was analyzed in a 5-year study. All mold isolates (n = 6,900) recovered in our laboratory from 2005 to 2009 were included in this study. According to a defined work flow, which in addition to troublesome phenotypic identification takes clinical relevance into account, 233 isolates were subjected to ITS sequence analysis. Sequencing resulted in successful identification for 78.6% of the analyzed isolates (57.1% at species level, 21.5% at genus level). In comparison, extended in-depth phenotypic characterization of the isolates subjected to sequencing achieved taxonomic assignment for 47.6% of these, with a mere 13.3% at species level. Optimization of DNA extraction further improved the efficacy of molecular identification. This study is the first of its kind to testify to the systematic implementation of sequence-based identification procedures in the routine workup of mold isolates in the diagnostic mycology laboratory.