13 research outputs found

    International Society of Human and Animal Mycology (ISHAM)-ITS reference DNA barcoding database - the quality controlled standard tool for routine identification of human and animal pathogenic fungi

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    Human and animal fungal pathogens are a growing threat worldwide leading to emerging infections and creating new risks for established ones. There is a growing need for a rapid and accurate identification of pathogens to enable early diagnosis and targeted antifungal therapy. Morphological and biochemical identification methods are time-consuming and require trained experts. Alternatively, molecular methods, such as DNA barcoding, a powerful and easy tool for rapid monophasic identification, offer a practical approach for species identification and less demanding in terms of taxonomical expertise. However, its wide-spread use is still limited by a lack of quality-controlled reference databases and the evolving recognition and definition of new fungal species/complexes. An international consortium of medical mycology laboratories was formed aiming to establish a quality controlled ITS database under the umbrella of the ISHAM working group on "DNA barcoding of human and animal pathogenic fungi." A new database, containing 2800 ITS sequences representing 421 fungal species, providing the medical community with a freely accessible tool at http://www.isham.org and http://its.mycologylab.org/ to rapidly and reliably identify most agents of mycoses, was established. The generated sequences included in the new database were used to evaluate the variation and overall utility of the ITS region for the identification of pathogenic fungi at intra-and interspecies level. The average intraspecies variation ranged from 0 to 2.25%. This highlighted selected pathogenic fungal species, such as the dermatophytes and emerging yeast, for which additional molecular methods/genetic markers are required for their reliable identification from clinical and veterinary specimens.This study was supported by an National Health and Medical Research Council of Australia (NH&MRC) grant [#APP1031952] to W Meyer, S Chen, V Robert, and D Ellis; CNPq [350338/2000-0] and FAPERJ [E-26/103.157/2011] grants to RM Zancope-Oliveira; CNPq [308011/2010-4] and FAPESP [2007/08575-1] Fundacao de Amparo Pesquisa do Estado de So Paulo (FAPESP) grants to AL Colombo; PEst-OE/BIA/UI4050/2014 from Fundacao para a Ciencia e Tecnologia (FCT) to C Pais; the Belgian Science Policy Office (Belspo) to BCCM/IHEM; the MEXBOL program of CONACyT-Mexico, [ref. number: 1228961 to ML Taylor and [122481] to C Toriello; the Institut Pasteur and Institut de Veil le Sanitaire to F Dromer and D Garcia-Hermoso; and the grants from the Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) and the Fundacao de Amparo a Pesquisa do Estado de Goias (FAPEG) to CM de Almeida Soares and JA Parente Rocha. I Arthur would like to thank G Cherian, A Higgins and the staff of the Molecular Diagnostics Laboratory, Division of Microbiology and Infectious Diseases, Path West, QEII Medial Centre. Dromer would like to thank for the technical help of the sequencing facility and specifically that of I, Diancourt, A-S Delannoy-Vieillard, J-M Thiberge (Genotyping of Pathogens and Public Health, Institut Pasteur). RM Zancope-Oliveira would like to thank the Genomic/DNA Sequencing Platform at Fundacao Oswaldo Cruz-PDTIS/FIOCRUZ [RPT01A], Brazil for the sequencing. B Robbertse and CL Schoch acknowledge support from the Intramural Research Program of the NIH, National Library of Medicine. T Sorrell's work is funded by the NH&MRC of Australia; she is a Sydney Medical School Foundation Fellow.info:eu-repo/semantics/publishedVersio

    Dual DNA barcoding for the molecular identification of the agents of invasive fungal infections

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    Invasive fungal infections, such as aspergillosis, candidiasis, and cryptococcosis, have significantly increased among immunocompromised people. To tackle these infections the first and most decisive step is the accurate identification of the causal pathogen. Routine identification of invasive fungal infections has progressed away from culture-dependent methods toward molecular techniques, including DNA barcoding, a highly efficient and widely used diagnostic technique. Fungal DNA barcoding previously relied on a single barcoding region, the internal transcribed spacer (ITS) region. However, this allowed only for 75% of all fungi to be correctly identified. As such, the translational elongation factor 1α (TEF1α) was recently introduced as the secondary barcode region to close the gap. Both loci together form the dual fungal DNA barcoding scheme. As a result, the ISHAM Barcoding Database has been expanded to include sequences for both barcoding regions to enable practical implementation of the dual barcoding scheme into clinical practice. The present study investigates the impact of the secondary barcode on the identification of clinically important fungal taxa, that have been demonstrated to cause severe invasive disease. Analysis of the barcoding regions was performed using barcoding gap analysis based on the genetic distances generated with the Kimura 2-parameter model. The secondary barcode demonstrated an improvement in identification for all taxa that were unidentifiable with the primary barcode, and when combined with the primary barcode ensured accurate identification for all taxa analyzed, making DNA barcoding an important, efficient and reliable addition to the diagnostic toolset of invasive fungal infections. Copyright © 2019 Hoang, Irinyi, Chen, Sorrell, the ISHAM Barcoding of Medical Fungi Working Group and Meyer. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms

    Database establishment for the secondary fungal DNA barcode translational elongation factor 1 alpha (TEF1 alpha)

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    With new or emerging fungal infections, human and animal fungal pathogens are a growing threat worldwide. Current diagnostic tools are slow, non-specific at the species and subspecies levels, and require specific morphological expertise to accurately identify pathogens from pure cultures. DNA barcodes are easily amplified, universal, short species-specific DNA sequences, which enable rapid identification by comparison with a well-curated reference sequence collection. The primary fungal DNA barcode, ITS region, was introduced in 2012 and is now routinely used in diagnostic laboratories. However, the ITS region only accurately identifies around 75% of all medically relevant fungal species, which has prompted the development of a secondary barcode to increase the resolution power and suitability of DNA barcoding for fungal disease diagnostics. The translational elongation factor 1 alpha (TEF1 alpha) was selected in 2015 as a secondary fungal DNA barcode, but it has not been implemented into practice, due to the absence of a reference database. Here, we have established a quality-controlled reference database for the secondary barcode that together with the ISHAM-ITS database, forms the ISHAM barcode database, available online at http://its.mycologylab.org/. We encourage the mycology community for active contributions623160169The authors thank Jeffrey M. Loch (U.S. Geological Survey, National Wildlife Health Center, Madison, USA) for submitting sequences and all reference centres and clinical microbiology laboratories that kindly contributed strains to this study. The study was supported by NH&MRC grants APP1031952 and APP1121936 to W.M., V.R., S.C., and T.C.S., and a REN grant from Western Sydney Local Health Research & Education Network to W.M., T.C.S., S.C., L.I. T.C.S. is a Sydney Medical Foundation Fello

    Database establishment for the secondary fungal DNA barcode translational elongation factor 1 alpha (TEF1 alpha)

    No full text
    With new or emerging fungal infections, human/animal fungal pathogens are a growing threat worldwide. Current diagnostic tools are slow, non-specific at the species and subspecies levels, and require specific morphological expertise to accurately identify pathogens from pure cultures. DNA barcodes are easily amplified, universal, short species-specific DNA sequences, which enable rapid identification by comparison with a well-curated reference sequence collection. The primary fungal DNA barcode, ITS region, was introduced in 2012 and is now routinely used in diagnostic laboratories. However, the ITS region only accurately identifies around 75% of all medically relevant fungal species, which has prompted the development of a secondary barcode to increase the resolution power and suitability of DNA barcoding for fungal disease diagnostics. The translational elongation factor 1α (TEF1α) was selected in 2015 as a secondary fungal DNA barcode, but has not been implemented into practice, due to the absence of a reference database. Here, we have established a quality-controlled reference database for the secondary barcode which together with the ISHAM-ITS database, forms the "ISHAM BARCODE DATABASE", available online at: http://its.mycologylab.org/. We encourage the mycology community for active contributions. The application of a dual DNA barcoding system enables accurate identification of all clinically important fungal pathogens
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