Aspergillus terreus sectorization: a morphological phenomenon shedding light on amphotericin B resistance mechanism

ABSTRACT Prolonged cultivation of certain filamentous fungi, including Aspergillus terreus, on drug-free medium leads to degeneration and morphological heterogeneity, marked by the emergence of fluffy mycelium-type sectors. This phenomenon may indicate alterations in antifungal susceptibility profil...

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Main Authors: David Eisele, Michael Blatzer, Anna Maria Dietl, Ulrike Binder, Christoph Müller, Ferry Hagen, Tongta Sae-Ong, Sascha Schäuble, Gianni Panagiotou, Roya Vahedi-Shahandashti, Cornelia Lass-Flörl
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Language:English
Published: American Society for Microbiology 2025-04-01
Series:mBio
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Online Access:https://journals.asm.org/doi/10.1128/mbio.03926-24
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author David Eisele
Michael Blatzer
Anna Maria Dietl
Ulrike Binder
Christoph Müller
Ferry Hagen
Tongta Sae-Ong
Sascha Schäuble
Gianni Panagiotou
Roya Vahedi-Shahandashti
Cornelia Lass-Flörl
author_facet David Eisele
Michael Blatzer
Anna Maria Dietl
Ulrike Binder
Christoph Müller
Ferry Hagen
Tongta Sae-Ong
Sascha Schäuble
Gianni Panagiotou
Roya Vahedi-Shahandashti
Cornelia Lass-Flörl
author_sort David Eisele
collection DOAJ
description ABSTRACT Prolonged cultivation of certain filamentous fungi, including Aspergillus terreus, on drug-free medium leads to degeneration and morphological heterogeneity, marked by the emergence of fluffy mycelium-type sectors. This phenomenon may indicate alterations in antifungal susceptibility profiles (particularly to amphotericin B (AmB) in A. terreus), as well as reductions or losses in conidiation, sexuality, secondary metabolite production, and/or virulence. In the present study, various characteristics of an AmB-resistant wild-type (WT) strain and its AmB-susceptible sectorized derivative (ATSec) were characterized. Compared to WT, ATSec exhibited increased susceptibility to AmB, reduced sporulation, and comparable sterol contents and virulence in Galleria mellonella. To elucidate the genes involved in AmB resistance, gene expression levels were compared between WT and ATSec with and without AmB treatment. The expression of P-type ATPase-related genes, which are implicated in membrane composition changes and consequently in AmB resistance, was significantly higher in the WT strain compared to ATSec. Moreover, the up-regulation of genes involved in the biosynthesis of polyketides—a diverse group of secondary metabolites—was higher in WT compared to ATSec, with a significant number of these genes also carrying at least one mutation. The findings of this study indicate that P-type ATPases may significantly be involved in AmB susceptibility and resistance observed in ATSec and WT strains. Additionally, mutations in polyketide synthase genes in ATSec may contribute to the phenotypic alterations associated with the sectorized phenotype.IMPORTANCEProlonged cultivation of certain filamentous fungi, including Aspergillus terreus, on drug-free medium leads to degeneration and morphological heterogeneity, marked by the emergence of fluffy mycelium-type sectors. This phenomenon may indicate alterations in antifungal susceptibility profiles (particularly to amphotericin B (AmB) in A. terreus), as well as reductions or losses in conidiation, sexuality, secondary metabolite production, and/or virulence. In the present study, various characteristics of an AmB-resistant wild-type strain (WT) and its AmB-susceptible sectorized derivative (ATSec) were characterized. Compared to WT, ATSec exhibited increased susceptibility to AmB, reduced sporulation, and comparable sterol contents and virulence in Galleria mellonella. To elucidate the genes involved in AmB resistance, gene expression levels were compared between WT and ATSec with and without AmB treatment. The expression of P-type ATPase-related genes, which are implicated in membrane composition changes and consequently in AmB resistance, was significantly higher in the WT strain compared to ATSec. Moreover, the up-regulation of genes involved in the biosynthesis of polyketides - a diverse group of secondary metabolites - was higher in WT compared to ATSec, with a significant number of these genes also carrying at least one mutation. The findings of this study indicate that P-type ATPases may significantly be involved in AmB susceptibility and resistance observed in ATSec and WT strains. Additionally, mutations in polyketide synthase genes in ATSec may contribute to the phenotypic alterations associated with the sectorized phenotype.
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spelling doaj-art-45768d58665a42b2af3af7ead3388e0f2025-08-20T02:16:46ZengAmerican Society for MicrobiologymBio2150-75112025-04-0116410.1128/mbio.03926-24Aspergillus terreus sectorization: a morphological phenomenon shedding light on amphotericin B resistance mechanismDavid Eisele0Michael Blatzer1Anna Maria Dietl2Ulrike Binder3Christoph Müller4Ferry Hagen5Tongta Sae-Ong6Sascha Schäuble7Gianni Panagiotou8Roya Vahedi-Shahandashti9Cornelia Lass-Flörl10Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, AustriaInstitute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, AustriaInstitute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, AustriaInstitute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, AustriaDepartment of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, GermanyDepartment of Medical Mycology, Westerdijk Fungal Biodiversity Institute (WI-KNAW), Utrecht, the NetherlandsDepartment of Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (Leibniz-HKI), Jena, GermanyDepartment of Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (Leibniz-HKI), Jena, GermanyDepartment of Microbiome Dynamics, Leibniz Institute for Natural Product Research and Infection Biology – Hans Knöll Institute (Leibniz-HKI), Jena, GermanyInstitute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, AustriaInstitute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, AustriaABSTRACT Prolonged cultivation of certain filamentous fungi, including Aspergillus terreus, on drug-free medium leads to degeneration and morphological heterogeneity, marked by the emergence of fluffy mycelium-type sectors. This phenomenon may indicate alterations in antifungal susceptibility profiles (particularly to amphotericin B (AmB) in A. terreus), as well as reductions or losses in conidiation, sexuality, secondary metabolite production, and/or virulence. In the present study, various characteristics of an AmB-resistant wild-type (WT) strain and its AmB-susceptible sectorized derivative (ATSec) were characterized. Compared to WT, ATSec exhibited increased susceptibility to AmB, reduced sporulation, and comparable sterol contents and virulence in Galleria mellonella. To elucidate the genes involved in AmB resistance, gene expression levels were compared between WT and ATSec with and without AmB treatment. The expression of P-type ATPase-related genes, which are implicated in membrane composition changes and consequently in AmB resistance, was significantly higher in the WT strain compared to ATSec. Moreover, the up-regulation of genes involved in the biosynthesis of polyketides—a diverse group of secondary metabolites—was higher in WT compared to ATSec, with a significant number of these genes also carrying at least one mutation. The findings of this study indicate that P-type ATPases may significantly be involved in AmB susceptibility and resistance observed in ATSec and WT strains. Additionally, mutations in polyketide synthase genes in ATSec may contribute to the phenotypic alterations associated with the sectorized phenotype.IMPORTANCEProlonged cultivation of certain filamentous fungi, including Aspergillus terreus, on drug-free medium leads to degeneration and morphological heterogeneity, marked by the emergence of fluffy mycelium-type sectors. This phenomenon may indicate alterations in antifungal susceptibility profiles (particularly to amphotericin B (AmB) in A. terreus), as well as reductions or losses in conidiation, sexuality, secondary metabolite production, and/or virulence. In the present study, various characteristics of an AmB-resistant wild-type strain (WT) and its AmB-susceptible sectorized derivative (ATSec) were characterized. Compared to WT, ATSec exhibited increased susceptibility to AmB, reduced sporulation, and comparable sterol contents and virulence in Galleria mellonella. To elucidate the genes involved in AmB resistance, gene expression levels were compared between WT and ATSec with and without AmB treatment. The expression of P-type ATPase-related genes, which are implicated in membrane composition changes and consequently in AmB resistance, was significantly higher in the WT strain compared to ATSec. Moreover, the up-regulation of genes involved in the biosynthesis of polyketides - a diverse group of secondary metabolites - was higher in WT compared to ATSec, with a significant number of these genes also carrying at least one mutation. The findings of this study indicate that P-type ATPases may significantly be involved in AmB susceptibility and resistance observed in ATSec and WT strains. Additionally, mutations in polyketide synthase genes in ATSec may contribute to the phenotypic alterations associated with the sectorized phenotype.https://journals.asm.org/doi/10.1128/mbio.03926-24Aspergillus terreusP-type ATPaseamphotericin B (AmB) resistanceculture degenerationsectorizationphenotypic heterogeneity
spellingShingle David Eisele
Michael Blatzer
Anna Maria Dietl
Ulrike Binder
Christoph Müller
Ferry Hagen
Tongta Sae-Ong
Sascha Schäuble
Gianni Panagiotou
Roya Vahedi-Shahandashti
Cornelia Lass-Flörl
Aspergillus terreus sectorization: a morphological phenomenon shedding light on amphotericin B resistance mechanism
mBio
Aspergillus terreus
P-type ATPase
amphotericin B (AmB) resistance
culture degeneration
sectorization
phenotypic heterogeneity
title Aspergillus terreus sectorization: a morphological phenomenon shedding light on amphotericin B resistance mechanism
title_full Aspergillus terreus sectorization: a morphological phenomenon shedding light on amphotericin B resistance mechanism
title_fullStr Aspergillus terreus sectorization: a morphological phenomenon shedding light on amphotericin B resistance mechanism
title_full_unstemmed Aspergillus terreus sectorization: a morphological phenomenon shedding light on amphotericin B resistance mechanism
title_short Aspergillus terreus sectorization: a morphological phenomenon shedding light on amphotericin B resistance mechanism
title_sort aspergillus terreus sectorization a morphological phenomenon shedding light on amphotericin b resistance mechanism
topic Aspergillus terreus
P-type ATPase
amphotericin B (AmB) resistance
culture degeneration
sectorization
phenotypic heterogeneity
url https://journals.asm.org/doi/10.1128/mbio.03926-24
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