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738. A Novel Molecular Diagnostic Assay for Identification of Fungal Pathogens

BACKGROUND: A rapid and accurate diagnostic method for invasive fungal infections remains a critical clinical need. We recently reported a rapid molecular method for bacterial species identification directly from clinical samples that targets highly abundant ribosomal RNA on a multiplexed hybridizat...

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Autores principales: Matzko, Michelle E, Martinsen, Melanie A, Sephton-Clark, Poppy, Cuomo, Christina, Bhattacharyya, Roby P
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Oxford University Press 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7776206/
http://dx.doi.org/10.1093/ofid/ofaa439.929
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author Matzko, Michelle E
Martinsen, Melanie A
Sephton-Clark, Poppy
Cuomo, Christina
Bhattacharyya, Roby P
author_facet Matzko, Michelle E
Martinsen, Melanie A
Sephton-Clark, Poppy
Cuomo, Christina
Bhattacharyya, Roby P
author_sort Matzko, Michelle E
collection PubMed
description BACKGROUND: A rapid and accurate diagnostic method for invasive fungal infections remains a critical clinical need. We recently reported a rapid molecular method for bacterial species identification directly from clinical samples that targets highly abundant ribosomal RNA on a multiplexed hybridization platform called NanoString. Here we report an adaptation of this assay that accurately distinguishes common fungal pathogens with limit of detection at a single yeast cell. METHODS: Building on our bacterial approach, we computationally designed specific hybridization probes targeting species-specific variable regions of fungal 18S and 28S rRNA from 12 clinically relevant fungi: Aspergillus fumigatus, Cryptococcus neoformans, and 10 Candida species, including Candida auris. Following mechanical lysis of crude specimens, fungi were detected from laboratory culture or artificial cerebrospinal fluid via multiplexed hybridization on a NanoString (Seattle, WA) instrument which yielded results within 7 hours from sample collection. Assay sensitivity was probed using serial dilutions of lysed C. albicans in culture, and cell-equivalents were confirmed by plating. RESULTS: Our hybridization probes targeting fungal rRNA specifically recognized all species tested to date: A. fumigatus, C. neoformans, and C. albicans with no cross-reactivity (Fig 1a). Serial dilutions of C. albicans lysate demonstrated a limit of detection around 0.1 cell equivalents without rRNA amplification (Fig 1b), capitalizing on the intrinsic abundance of rRNA in fungal cells. Figure 1. [Image: see text] CONCLUSION: We adapted a rapid, ultrasensitive hybridization-based diagnostic assay that has proven successful in bacteria, to fungi. Here we show the accurate detection of Aspergillus, Cryptococcus, and Candida species, including a computational design that will enable the distinction of 10 different Candida species, including C. auris, within hours from clinical specimen collection. DISCLOSURES: All Authors: No reported disclosures
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spelling pubmed-77762062021-01-07 738. A Novel Molecular Diagnostic Assay for Identification of Fungal Pathogens Matzko, Michelle E Martinsen, Melanie A Sephton-Clark, Poppy Cuomo, Christina Bhattacharyya, Roby P Open Forum Infect Dis Poster Abstracts BACKGROUND: A rapid and accurate diagnostic method for invasive fungal infections remains a critical clinical need. We recently reported a rapid molecular method for bacterial species identification directly from clinical samples that targets highly abundant ribosomal RNA on a multiplexed hybridization platform called NanoString. Here we report an adaptation of this assay that accurately distinguishes common fungal pathogens with limit of detection at a single yeast cell. METHODS: Building on our bacterial approach, we computationally designed specific hybridization probes targeting species-specific variable regions of fungal 18S and 28S rRNA from 12 clinically relevant fungi: Aspergillus fumigatus, Cryptococcus neoformans, and 10 Candida species, including Candida auris. Following mechanical lysis of crude specimens, fungi were detected from laboratory culture or artificial cerebrospinal fluid via multiplexed hybridization on a NanoString (Seattle, WA) instrument which yielded results within 7 hours from sample collection. Assay sensitivity was probed using serial dilutions of lysed C. albicans in culture, and cell-equivalents were confirmed by plating. RESULTS: Our hybridization probes targeting fungal rRNA specifically recognized all species tested to date: A. fumigatus, C. neoformans, and C. albicans with no cross-reactivity (Fig 1a). Serial dilutions of C. albicans lysate demonstrated a limit of detection around 0.1 cell equivalents without rRNA amplification (Fig 1b), capitalizing on the intrinsic abundance of rRNA in fungal cells. Figure 1. [Image: see text] CONCLUSION: We adapted a rapid, ultrasensitive hybridization-based diagnostic assay that has proven successful in bacteria, to fungi. Here we show the accurate detection of Aspergillus, Cryptococcus, and Candida species, including a computational design that will enable the distinction of 10 different Candida species, including C. auris, within hours from clinical specimen collection. DISCLOSURES: All Authors: No reported disclosures Oxford University Press 2020-12-31 /pmc/articles/PMC7776206/ http://dx.doi.org/10.1093/ofid/ofaa439.929 Text en © The Author 2020. Published by Oxford University Press on behalf of Infectious Diseases Society of America. http://creativecommons.org/licenses/by-nc-nd/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs licence (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial reproduction and distribution of the work, in any medium, provided the original work is not altered or transformed in any way, and that the work is properly cited. For commercial re-use, please contact journals.permissions@oup.com
spellingShingle Poster Abstracts
Matzko, Michelle E
Martinsen, Melanie A
Sephton-Clark, Poppy
Cuomo, Christina
Bhattacharyya, Roby P
738. A Novel Molecular Diagnostic Assay for Identification of Fungal Pathogens
title 738. A Novel Molecular Diagnostic Assay for Identification of Fungal Pathogens
title_full 738. A Novel Molecular Diagnostic Assay for Identification of Fungal Pathogens
title_fullStr 738. A Novel Molecular Diagnostic Assay for Identification of Fungal Pathogens
title_full_unstemmed 738. A Novel Molecular Diagnostic Assay for Identification of Fungal Pathogens
title_short 738. A Novel Molecular Diagnostic Assay for Identification of Fungal Pathogens
title_sort 738. a novel molecular diagnostic assay for identification of fungal pathogens
topic Poster Abstracts
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7776206/
http://dx.doi.org/10.1093/ofid/ofaa439.929
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