Direct Visualization of Fungal Burden in Filamentous Fungus-Infected Silkworms

Invasive fungal infections (IFIs) are difficult to diagnose and to treat and, despite several available antifungal drugs, cause high mortality rates. In the past decades, the incidence of IFIs has continuously increased. More recently, SARS-CoV-2-associated lethal IFIs have been reported worldwide i...

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Bibliographic Details
Main Authors: Yidong Yu, Ann-Katrin Wolf, Sina Thusek, Thorsten Heinekamp, Michael Bromley, Sven Krappmann, Ulrich Terpitz, Kerstin Voigt, Axel A. Brakhage, Andreas Beilhack
Format: Article
Language:English
Published: MDPI AG 2021-02-01
Series:Journal of Fungi
Subjects:
Online Access:https://www.mdpi.com/2309-608X/7/2/136
Description
Summary:Invasive fungal infections (IFIs) are difficult to diagnose and to treat and, despite several available antifungal drugs, cause high mortality rates. In the past decades, the incidence of IFIs has continuously increased. More recently, SARS-CoV-2-associated lethal IFIs have been reported worldwide in critically ill patients. Combating IFIs requires a more profound understanding of fungal pathogenicity to facilitate the development of novel antifungal strategies. Animal models are indispensable for studying fungal infections and to develop new antifungals. However, using mammalian animal models faces various hurdles including ethical issues and high costs, which makes large-scale infection experiments extremely challenging. To overcome these limitations, we optimized an invertebrate model and introduced a simple calcofluor white (CW) staining protocol to macroscopically and microscopically monitor disease progression in silkworms (<i>Bombyx mori</i>) infected with the human pathogenic filamentous fungi <i>Aspergillus fumigatus</i> and <i>Lichtheimia corymbifera</i>. This advanced silkworm <i>A. fumigatus</i> infection model could validate knockout mutants with either attenuated, strongly attenuated or unchanged virulence. Finally, CW staining allowed us to efficiently visualize antifungal treatment outcomes in infected silkworms. Conclusively, we here present a powerful animal model combined with a straightforward staining protocol to expedite large-scale in vivo research of fungal pathogenicity and to investigate novel antifungal candidates.
ISSN:2309-608X