Related Experiment Video

Updated: Aug 25, 2026

Whole Genome Sequencing of Candida glabrata for Detection of Markers of Antifungal Drug Resistance
08:45

Whole Genome Sequencing of Candida glabrata for Detection of Markers of Antifungal Drug Resistance

Published on: December 28, 2017

Aspergillus fumigatus variant with decreased susceptibility to multiple antifungals

S Arunmozhi Balajee1, Molly Weaver, Alexander Imhof

  • 1Program in Infectious Diseases, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA.

Antimicrobial Agents and Chemotherapy
|March 30, 2004
PubMed

Insights

Antifungal resistance in Aspergillus fumigatus is a growing concern. This study identified a unique, poorly sporulating A. fumigatus variant with reduced susceptibility to multiple antifungals, including itraconazole.

Area of Science:

  • Medical Mycology
  • Infectious Diseases
  • Antimicrobial Resistance

Background:

  • Itraconazole (ITZ) resistance in Aspergillus fumigatus is known but not fully understood.
  • Invasive fungal infections pose significant risks, especially in immunocompromised patients like stem cell transplant recipients.

Purpose of the Study:

  • To assess the prevalence and clinical significance of ITZ resistance in A. fumigatus isolates from stem cell transplant patients.
  • To characterize unusual A. fumigatus isolates exhibiting reduced antifungal susceptibility.

Main Methods:

  • Antifungal susceptibility testing (MICs) for ITZ, voriconazole, caspofungin, and amphotericin B.
  • Phenotypic characterization including colony morphology and sporulation.
  • Molecular typing using randomly amplified polymorphic DNA-PCR and gene sequencing (18S rRNA, mitochondrial cytochrome b).

Main Results:

  • 10 of 128 A. fumigatus isolates showed high ITZ MICs (>1 µg/ml).
  • Seven atypical isolates with high ITZ MICs displayed a distinct white colony phenotype due to slow sporulation.
  • These atypical isolates also exhibited high MICs for voriconazole and caspofungin, and in some cases, amphotericin B.
  • Molecular analysis revealed unique mitochondrial cytochrome b gene sequences in the atypical isolates, suggesting a distinct genetic variant.

Conclusions:

  • A genetically unique, poorly sporulating variant of A. fumigatus may be emerging.
  • This variant demonstrates decreased susceptibility to multiple antifungal agents.
  • Further research is needed to understand the prevalence and clinical impact of this antifungal-resistant A. fumigatus variant.

More Related Videos

Isolation of Culturable Yeasts and Molds from Soils to Investigate Fungal Population Structure10:33

Isolation of Culturable Yeasts and Molds from Soils to Investigate Fungal Population Structure

Published on: May 27, 2022

Related Concept Videos

Antifungal Agents01:15

Antifungal Agents

Amphotericin B is a broad-spectrum antifungal agent that exploits structural differences between fungal and mammalian cell membranes. Its amphipathic structure—featuring a hydrophobic polyene-lactone ring and a hydrophilic region containing mycosamine and carboxylic acid groups—enables selective binding to ergosterol, a sterol predominantly found in fungal plasma membranes. This selective interaction underlies the drug’s antifungal activity, although weak binding to cholesterol contributes to...
Fungal Phylum Ascomycota01:28

Fungal Phylum Ascomycota

Phylum Ascomycota, a major division within the subkingdom Dikarya, comprises a diverse range of fungal species, including both unicellular yeasts and filamentous molds such as Aspergillus and Penicillium. These fungi thrive in a variety of habitats, from aquatic ecosystems to terrestrial environments, playing crucial ecological and economic roles.Morphology and ReproductionThe defining characteristic of Ascomycetes, commonly referred to as sac fungi, is the ascus—a sac-like structure that...
Cryptococcal Meningitis01:27

Cryptococcal Meningitis

Cryptococcal meningitis is a life-threatening opportunistic infection predominantly associated with HIV/AIDS, accounting for over 100,000 deaths annually worldwide. However, it also affects individuals with other forms of immunosuppression, including those undergoing immunosuppressive therapy, organ transplant recipients, patients with innate immunodeficiencies, and individuals with hematological disorders. The infection is caused mainly by Cryptococcus neoformans and Cryptococcus gattii,...
Fungal Group Zygomycota01:29

Fungal Group Zygomycota

Zygomycota, previously classified as a distinct fungal group, are primarily terrestrial, saprophytic molds that play a crucial role as decomposers. Recent phylogenetic studies have revealed that these fungi are now divided into two major clades — Mucoromycota, which includes many symbiotic species, and Zoopagomycota, which primarily consists of parasitic and pathogenic fungi. These groups exhibit distinct ecological roles and reproductive strategies while sharing key structural and...
Fungal Phylum Microsporidia01:28

Fungal Phylum Microsporidia

Microsporidia are a group of obligate intracellular fungi that were initially classified as protists but were later reclassified based on phylogenetic, molecular, and structural evidence linking them to the Chytridiomycota. These unicellular, non-motile organisms are highly specialized parasites that infect a wide range of animal hosts, including humans. They have evolved extensive genomic and metabolic reductions, making them highly dependent on their hosts for survival.Morphology and Genomic...
Anthelminthic Agents01:15

Anthelminthic Agents

Anthelmintic drugs differ significantly from antiparasitic therapies targeting protozoa, primarily due to differences in parasite biology. Whereas most protozoal treatments act on proliferating cells, anthelmintics are typically directed against mature, nonproliferative helminths. The therapeutic approach considers the helminth's reliance on neuromuscular coordination, glucose metabolism, and microtubular integrity for survival, reproduction, and localization within the host. Most anthelmintics...