Cited by 23Antifungal resistance and susceptibilityFungal and yeast genetics researchFungal Plant Pathogen Control

Approaches for identifying and measuring heteroresistance in azole-susceptible Candida isolates

Open access
Gautier, Cécile, Maciel, Eli I., Ene, Iuliana V.·2024·Microbiology Spectrum

Abstract

Heteroresistance to antifungal agents poses a significant challenge in the treatment of fungal infections. Currently, the absence of established methods for detecting and measuring heteroresistance impedes progress in understanding this phenomenon in fungal pathogens. In response to this gap, we present a comprehensive set of new and optimized methods designed to detect and quantify azole heteroresistance in Candida albicans . Here, we define two primary assays for measuring heteroresistance: population analysis profiling, based on growth on solid medium, and single-cell assays, based on growth in liquid culture. We observe good correlations between the measurements obtained with liquid and solid assays, validating their utility for studying azole heteroresistance. We also highlight that disk diffusion assays could serve as an additional tool for the rapid detection of heteroresistance. These methods collectively provide a versatile toolkit for researchers seeking to assess heteroresistance in C. albicans . They also serve as a critical step forward in the characterization of antifungal heteroresistance, providing a framework for investigating this phenomenon in diverse fungal species and in the context of other antifungal agents. Ultimately, these advancements will enhance our ability to effectively measure antifungal drug responses and combat fungal infections. IMPORTANCE: Heteroresistance involves varying antimicrobial susceptibility within a clonal population. This phenomenon allows the survival of rare resistant subpopulations during drug treatment, significantly complicating the effective management of infections. However, the absence of established detection methods hampers progress in understanding this phenomenon in human fungal pathogens. We propose a comprehensive toolkit to address this gap in the yeast Candida albicans , encompassing population analysis profiling, single-cell assays, and disk diffusion assays. By providing robust and correlated measurements through both solid and liquid assays, this work will provide a framework for broader applications across clinically relevant Candida species. These methods will enhance our ability to understand this phenomenon and the failure of antifungal therapy.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1128/spectrum.04041-23

Cites

58 of 58 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • For diagnosed fungal infections, antifungal heteroresistance may lead to persistent infections that require longer or more aggressive treatment regimens.

    “For diagnosed fungal infections, it may lead to persistent infections that require longer or more aggressive treatment regimens [27,28,29,30].”

    From Insight into the Mechanisms and Clinical Relevance of Antifungal Heteroresistance (2025) · cites this paper as [30]

    The Introduction (page not available in our copy) links fungal heteroresistance to relapse during azole treatment and failure to clear infection, supporting the possibility of persistent infection. It does not say that patients require longer or more aggressive treatment regimens. (LLM, conf=0.86)

    Experimental — accuracy not yet measured
  • PAP assay has been proved to efficiently test heteroresistance to azoles and echinocandins in C. albicans, C. haemulonii, C. tropicalis, N. glabrata, C. parapsilosis, C. neoformans and S. cerevisiae.

    “PAP has been proved to efficiently test the heteroresistance to azoles and echinocandins in C. albicans, C. haemulonii, C. tropicalis, N. glabrata, C. parapsilosis, C. neoformans and S. cerevisiae, etc. [30].”

    From Insight into the Mechanisms and Clinical Relevance of Antifungal Heteroresistance (2025) · cites this paper as [30]

    The Results sections report that PAP assays measured fluconazole heteroresistance in C. albicans and detected it in some isolates of other listed yeasts. But the study did not test echinocandins, and it recovered no heteroresistant colonies from its C. parapsilosis or S. cerevisiae isolates. The Results mention earlier PAP adaptations for C. neoformans and echinocandin treatment; they do not establish efficient testing for both drug classes across every species named. (LLM, conf=0.90)

    Experimental — accuracy not yet measured
  • Single-cell assays may reveal a wide spectrum of adaptation mechanisms.

    “Though the protocols are lengthier, they may reveal a wide spectrum of adaptation mechanisms [30].”

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Authors
Gautier, C., Maciel, E. I., & Ene, I. V.
Affiliations
Institut Pasteur (FR)
Corresponding author
Ene, Iuliana V.
Venue
Microbiology Spectrum
Published
2024-04-02
Volume
12
Issue
4
Pages
e0404123-e0404123
ISSN
2165-0497 (ISSN-L)
OpenAlex
W4393411060
Cited by
23
References
58
Citations by year
2026: 12 · 2025: 9 · 2024: 2
FWCI
7.91
Type
journal article
Language
en
Open access
Locations
  • Microbiology Spectrum (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • HAL (submittedVersion, cc-by)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion)
Funders
  • Agence Nationale de la Recherche (GENOMEHET)
  • Fondation pour la Recherche Médicale (Espoirs de la Recherche Postdoctoral Fellowship)
  • Institut Pasteur (Pasteur Carnot PTR)
  • CIFAR
Topics
  • Health Sciences › Medicine › Infectious Diseases › Antifungal resistance and susceptibility
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Fungal and yeast genetics research
  • Life Sciences › Agricultural and Biological Sciences › Ecology, Evolution, Behavior and Systematics › Fungal Plant Pathogen Control
Keywords
heteroresistance, azole resistance, Candida albicans, antifungal susceptibility, population analysis profiling, single cell testing, disk diffusion, fungal drug resistance, antifungal treatment failure
MeSH terms
Antifungal Agents, Azoles, Candida, Candida albicans, Humans, Microbial Sensitivity Tests, Mycoses, Drug Resistance, Fungal

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review