Intra-Genomic Internal Transcribed Spacer Region Sequence Heterogeneity and Molecular Diagnosis in Clinical Microbiology

Internal transcribed spacer region (ITS) sequencing is the most extensively used technology for accurate molecular identification of fungal pathogens in clinical microbiology laboratories. Intra-genomic ITS sequence heterogeneity, which makes fungal identification based on direct sequencing of PCR p...

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Main Authors: Zhao, Ying, Tsang, Chi-Ching, Xiao, Meng, Cheng, Jingwei, Xu, Yingchun, Lau, Susanna K. P., Woo, Patrick C. Y.
Format: Online
Language:English
Published: MDPI 2015
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4632790/
id pubmed-4632790
recordtype oai_dc
spelling pubmed-46327902015-11-23 Intra-Genomic Internal Transcribed Spacer Region Sequence Heterogeneity and Molecular Diagnosis in Clinical Microbiology Zhao, Ying Tsang, Chi-Ching Xiao, Meng Cheng, Jingwei Xu, Yingchun Lau, Susanna K. P. Woo, Patrick C. Y. Article Internal transcribed spacer region (ITS) sequencing is the most extensively used technology for accurate molecular identification of fungal pathogens in clinical microbiology laboratories. Intra-genomic ITS sequence heterogeneity, which makes fungal identification based on direct sequencing of PCR products difficult, has rarely been reported in pathogenic fungi. During the process of performing ITS sequencing on 71 yeast strains isolated from various clinical specimens, direct sequencing of the PCR products showed ambiguous sequences in six of them. After cloning the PCR products into plasmids for sequencing, interpretable sequencing electropherograms could be obtained. For each of the six isolates, 10–49 clones were selected for sequencing and two to seven intra-genomic ITS copies were detected. The identities of these six isolates were confirmed to be Candida glabrata (n = 2), Pichia (Candida) norvegensis (n = 2), Candida tropicalis (n = 1) and Saccharomyces cerevisiae (n = 1). Multiple sequence alignment revealed that one to four intra-genomic ITS polymorphic sites were present in the six isolates, and all these polymorphic sites were located in the ITS1 and/or ITS2 regions. We report and describe the first evidence of intra-genomic ITS sequence heterogeneity in four different pathogenic yeasts, which occurred exclusively in the ITS1 and ITS2 spacer regions for the six isolates in this study. MDPI 2015-10-22 /pmc/articles/PMC4632790/ /pubmed/26506340 http://dx.doi.org/10.3390/ijms161025067 Text en © 2015 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/4.0/).
repository_type Open Access Journal
institution_category Foreign Institution
institution US National Center for Biotechnology Information
building NCBI PubMed
collection Online Access
language English
format Online
author Zhao, Ying
Tsang, Chi-Ching
Xiao, Meng
Cheng, Jingwei
Xu, Yingchun
Lau, Susanna K. P.
Woo, Patrick C. Y.
spellingShingle Zhao, Ying
Tsang, Chi-Ching
Xiao, Meng
Cheng, Jingwei
Xu, Yingchun
Lau, Susanna K. P.
Woo, Patrick C. Y.
Intra-Genomic Internal Transcribed Spacer Region Sequence Heterogeneity and Molecular Diagnosis in Clinical Microbiology
author_facet Zhao, Ying
Tsang, Chi-Ching
Xiao, Meng
Cheng, Jingwei
Xu, Yingchun
Lau, Susanna K. P.
Woo, Patrick C. Y.
author_sort Zhao, Ying
title Intra-Genomic Internal Transcribed Spacer Region Sequence Heterogeneity and Molecular Diagnosis in Clinical Microbiology
title_short Intra-Genomic Internal Transcribed Spacer Region Sequence Heterogeneity and Molecular Diagnosis in Clinical Microbiology
title_full Intra-Genomic Internal Transcribed Spacer Region Sequence Heterogeneity and Molecular Diagnosis in Clinical Microbiology
title_fullStr Intra-Genomic Internal Transcribed Spacer Region Sequence Heterogeneity and Molecular Diagnosis in Clinical Microbiology
title_full_unstemmed Intra-Genomic Internal Transcribed Spacer Region Sequence Heterogeneity and Molecular Diagnosis in Clinical Microbiology
title_sort intra-genomic internal transcribed spacer region sequence heterogeneity and molecular diagnosis in clinical microbiology
description Internal transcribed spacer region (ITS) sequencing is the most extensively used technology for accurate molecular identification of fungal pathogens in clinical microbiology laboratories. Intra-genomic ITS sequence heterogeneity, which makes fungal identification based on direct sequencing of PCR products difficult, has rarely been reported in pathogenic fungi. During the process of performing ITS sequencing on 71 yeast strains isolated from various clinical specimens, direct sequencing of the PCR products showed ambiguous sequences in six of them. After cloning the PCR products into plasmids for sequencing, interpretable sequencing electropherograms could be obtained. For each of the six isolates, 10–49 clones were selected for sequencing and two to seven intra-genomic ITS copies were detected. The identities of these six isolates were confirmed to be Candida glabrata (n = 2), Pichia (Candida) norvegensis (n = 2), Candida tropicalis (n = 1) and Saccharomyces cerevisiae (n = 1). Multiple sequence alignment revealed that one to four intra-genomic ITS polymorphic sites were present in the six isolates, and all these polymorphic sites were located in the ITS1 and/or ITS2 regions. We report and describe the first evidence of intra-genomic ITS sequence heterogeneity in four different pathogenic yeasts, which occurred exclusively in the ITS1 and ITS2 spacer regions for the six isolates in this study.
publisher MDPI
publishDate 2015
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4632790/
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