Frontiers in Microbiology (Jul 2019)

Dual DNA Barcoding for the Molecular Identification of the Agents of Invasive Fungal Infections

  • Minh Thuy Vi Hoang,
  • Minh Thuy Vi Hoang,
  • Laszlo Irinyi,
  • Laszlo Irinyi,
  • Laszlo Irinyi,
  • Sharon C. A. Chen,
  • Sharon C. A. Chen,
  • Sharon C. A. Chen,
  • Tania C. Sorrell,
  • Tania C. Sorrell,
  • Tania C. Sorrell,
  • The ISHAM Barcoding of Medical Fungi Working Group,
  • Wieland Meyer,
  • Wieland Meyer,
  • Wieland Meyer,
  • Wieland Meyer,
  • Michael Arabatzis,
  • Ian Arthur,
  • Jose F. Cano-Lira,
  • Gianluigi Cardinali,
  • Laura Rosio Castañón,
  • Sharon Chen,
  • Wen Chen,
  • Ariya Chindamporn,
  • Arnaldo L. Colombo,
  • Marie Desnos-Ollivier,
  • Wilhelm de Beer,
  • Sybren de Hoog,
  • Françoise Dromer,
  • Dea Garcia-Hermoso,
  • Marieka Gryzenhout,
  • Josep Guarro,
  • Catriona Halliday,
  • Marijke Hendrickx,
  • Sabine Huhndorf,
  • Laszlo Irinyi,
  • C. Andre Levesque,
  • Wieland Meyer,
  • Maria Luiza Moretti,
  • Mauro de Medeiros Muniz,
  • Analy Salles de Azevedo Melo,
  • Angela Satie Nishikaku,
  • Anne-Cécile Normand,
  • Célia Pais,
  • Renaud Piarroux,
  • Stéphane Ranque,
  • Barbara Robbertse,
  • Vincent Robert,
  • Conrad L. Schoch,
  • Keith A. Seifert,
  • Célia Maria de Almeida Soares,
  • Tania C. Sorrell,
  • John L. Spouge,
  • Dirk Stubbe,
  • Maria Lucia Taylor,
  • Conchita Toriello,
  • Aristea Velegraki,
  • Chompoonek Yurayart,
  • Rosely Maria Zancopé-Oliveira

DOI
https://doi.org/10.3389/fmicb.2019.01647
Journal volume & issue
Vol. 10

Abstract

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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.

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