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Cited by 69Antifungal resistance and susceptibilityFungal Plant Pathogen ControlFungal and yeast genetics research

Delineation of the Direct Contribution of Candida auris ERG11 Mutations to Clinical Triazole Resistance

Open access
Rybak, Jeffrey M., Sharma, Cheshta, Doorley, Laura A., Barker, Katherine S., Palmer, Glen E., Rogers, P. David·2021·Microbiology Spectrum
DOI 10.1128/spectrum.01585-21PMC PMC8653815
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Abstract

Candida auris is an emerging multidrug-resistant and health care-associated pathogen of urgent clinical concern. The triazoles are the most widely prescribed antifungal agents worldwide and are commonly utilized for the treatment of invasive Candida infections.

AI snapshot

Written from the paper’s full text.

TL;DR

Using Cas9-RNP allele swaps in *Candida auris* clinical isolates, this study shows that the three common *ERG11* mutations (VF125AL, Y132F, K143R) directly increase fluconazole and voriconazole MICs by 8- to 16-fold but do not alone confer clinical fluconazole resistance. Other triazoles (isavuconazole, itraconazole, posaconazole) were largely unaffected, and resistance in a clinical isolate also required additional factors such as TAC1B-mediated efflux.

Key findings

  • Introducing *ERG11* VF125AL, Y132F, or K143R into fluconazole-susceptible AR0387 raised fluconazole MIC from 0.5 to 8 mg/L (16-fold) and increased voriconazole MIC by 4- to 16-fold; isavuconazole, itraconazole, and posaconazole MICs changed by ≤1 dilution.
  • Correcting the native *ERG11* K143R allele to wild type in fluconazole-resistant AR0390 reduced fluconazole MIC from 256 to 16 mg/L (16-fold) and voriconazole MIC from 0.25 to 0.03 mg/L (8-fold), with minimal changes for the other triazoles.
  • None of the three *ERG11* mutations alone produced clinical fluconazole resistance by tentative CDC breakpoints in AR0387; after K143R correction, AR0390 still had fluconazole MIC 16 mg/L versus 0.5 mg/L in AR0387, likely reflecting combined effects with a TAC1B A640V mutation and Cdr1 efflux.
  • The paper reports that >90% of characterized *C. auris* clinical isolates are fluconazole resistant and that nearly all fluconazole-resistant isolates carry one of these three *ERG11* mutations.

Methods

  • Cas9-ribonucleoprotein-mediated allele swap with a SAT-FLP cassette replaced the native *ERG11* allele in AR0387 with alleles from AR0383 (VF125AL), UTHSCA DI-19-24 (Y132F), and AR0390 (K143R); reciprocally, wild-type *ERG11* was introduced into AR0390. Transformants were confirmed by Sanger sequencing and qPCR for single-copy *ERG11*.
  • Susceptibility testing used modified CLSI broth microdilution at 24 h with a 50% growth inhibition endpoint, in biological duplicate with three technical replicates, plus Etest per CLSI M44-A2.
  • Clinical isolates AR0387 (B8441) and AR0390 (B11205) were obtained from the CDC Antibiotic Resistance Isolate Bank; strains were propagated in YPD medium.

Limitations

  • The paper states that none of the three *ERG11* mutations alone conferred clinical fluconazole resistance, and that AR0390 also carries a TAC1B A640V mutation likely causing Cdr1 overexpression; the high resistance in that isolate is therefore likely due to combined effects, with most fluconazole-resistant *C. auris* isolates carrying mutations in both *TAC1B* and *ERG11*.
  • Evident from the text: only two *C. auris* genetic backgrounds and three *ERG11* alleles were tested, and the study reports in vitro MIC data only, without in vivo infection models or clinical outcome data.
  • Evident from the text: the direct contribution of TAC1B/efflux or other resistance mechanisms was not experimentally isolated here, so the relative quantitative contribution of *ERG11* mutations versus other factors in clinical isolates remains incompletely defined.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1128/spectrum.01585-21

Cites

20 of 20 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 36 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    In the AR0390 background, correction of the K143R encoding mutation to wild type led to an 8-fold decrease in voriconazole MIC.

    “Moreover, an 8-fold decrease in resistance to voriconazole was observed upon introduction of the ERG11WT allele, again following the changes observed with fluconazole MIC (Fig. 2B).”
    Quote in the paperSubstantial claim
  • Findingown data

    In the AR0390 background, correction of the K143R encoding mutation to wild type led to a 16-fold decrease in fluconazole MIC relative to parental AR0390 (MIC 256 mg/L).

    “The resulting ERG11WT transformants, were observed to exhibit an 16-fold decrease in fluconazole MIC relative to the parental AR0390 (MIC 256 mg/L) (Fig. 3A).”
    Quote in the paperSubstantial claim
  • Findingown data

    In the AR0390 background, MIC for isavuconazole, itraconazole, and posaconazole were largely unchanged upon correction of K143R to wild type.

    “However, consistent with the observations in the AR0387 background, MIC for isavuconazole, itraconazole, and posaconazole were largely unchanged (Table 1).”
    Quote in the paperSubstantial claim
  • Findingown data

    Introduction of each of the three resistance-associated ERG11 alleles into the AR0387 background increased voriconazole MIC by 4- to 16-fold.

    “Changes in voriconazole MIC were observed to be consistent with those observed in fluconazole MIC and increased by 4- to 16-fold for all strains with resistance-associated ERG11 alleles (Fig. 2A).”
    Quote in the paperSubstantial claim
  • Findingown data

    Introduction of any of the ERG11 alleles into AR0387 did not substantially change MIC for isavuconazole, itraconazole, or posaconazole (1 dilution or less).

    “However, MIC for isavuconazole, itraconazole, and posaconazole were relatively unchanged (1 dilution or less) upon introduction any of the ERG11 alleles into AR0387 (Table 1).”
    Quote in the paperSubstantial claim
  • May combine two claims. 14
  • Classified as probably not a substantial claim. 15

  • May combine two claims.

    Findingown data

    Correction of the K143R substitution to wild type in resistant clinical isolate AR0390 conferred susceptibility to fluconazole, but the MIC remained high (16 mg/L) compared with susceptible isolate AR0387 (0.5 mg/L).

    “Likewise, while correction of the K143R substitution to the wild type sequence in resistant clinical isolate AR0390 did confer susceptibility to fluconazole, the MIC remained high (16 mg/L) compared with the susceptible isolate AR0387 (0.5 mg/L).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The increase in fluconazole resistance was also observed by Etest, with the strain harboring the ERG11Y132F allele exhibiting a slightly more prominent change in the zone of inhibition on solid media.

    “This increase in fluconazole resistance was also observed by Etest, with the strain harboring the ERG11Y132F allele exhibiting a slightly more prominent change in the zone of inhibition on solid media (Fig. 1B).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Study design and conductown data

    The manipulation control strain in AR0390 still harboring K143R had only a single dilution reduction in fluconazole MIC (128 mg/L) by broth microdilution, with no appreciable change in zone of inhibition by Etest.

    “Conversely the manipulation control strain, still harboring the ERG11K143R allele, was found to have only a single dilution reduction in fluconazole MIC (128 mg/L) by broth microdilution, with no appreciable change in the zone of inhibition observed by Etest (Fig. 3B).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Mutations in C. auris ERG11 significantly contribute to fluconazole and voriconazole resistance, but alone cannot explain the substantially elevated MIC observed among clinical isolates of C. auris.

    “Taken together, these findings demonstrate that mutations in C. auris ERG11 significantly contribute to fluconazole and voriconazole resistance, but alone cannot explain the substantially elevated MIC observed among clinical isolates of C. auris.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    Mutations in sterol-demethylase have variable and agent-specific effects on the MICs of triazole antifungals.

    “Frequently reported in association with triazole resistance in both yeast and molds, mutations in sterol-demethylase have been observed to have variable and agent specific effects on the MICs of triazole antifungals, potentially as a result of agent-specific stabilizing interactions with sterol-demethylase residues (4, 5).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [4] Warrilow AG, Nishimoto AT, Parker JE, Price CL, Flowers SA, Kelly DE, Rogers PD, Kelly SL. 2019. The evolution of azole resistance in Candida albicans sterol 14alpha-demethylase (CYP51) through incremental amino acid substitutions. Antimicrob Agents Chemother 63. doi: 10.1128/AAC.02586-18. PMC6496074 30783005 source

      Not checked in the free run.

    • cites [5] Flowers SA, Colon B, Whaley SG, Schuler MA, Rogers PD. 2015. Contribution of clinically derived mutations in ERG11 to azole resistance in Candida albicans. Antimicrob Agents Chemother 59: 450– 460. doi: 10.1128/AAC.03470-14. 25385095 PMC4291385 source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation

    Among pathogenic fungi, the most commonly reported mechanism of resistance to triazoles is acquisition of mutations in the gene encoding sterol-demethylase.

    “Among pathogenic fungi, the most commonly reported mechanism of resistance to the triazole class of antifungals is the acquisition of mutations in the gene encoding sterol-demethylase, the enzyme which these agents directly interact with and inhibit (1–3).”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [1] Rybak JM, Fortwendel JR, Rogers PD. 2019. Emerging threat of triazole-resistant Aspergillus fumigatus. J Antimicrob Chemother 74: 835– 842. doi: 10.1093/jac/dky517. 30561652 PMC6657284 source

      Not checked in the free run.

    • cites [2] Nishimoto AT, Sharma C, Rogers PD. 2020. Molecular and genetic basis of azole antifungal resistance in the opportunistic pathogenic fungus Candida albicans. J Antimicrob Chemother 75: 257– 270. doi: 10.1093/jac/dkz400. 31603213 PMC8204710 source

      Not checked in the free run.

    • cites [3] Perlin DS, Rautemaa-Richardson R, Alastruey-Izquierdo A. 2017. The global problem of antifungal resistance: prevalence, mechanisms, and management. Lancet Infect Dis 17: e383– e392. doi: 10.1016/S1473-3099(17)30316-X. 28774698 source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Heterologous expression of C. auris ERG11 alleles carrying the Y132F and K143R substitutions in Saccharomyces cerevisiae revealed that both mutations increase fluconazole resistance.

    “Heterologous expression of C. auris ERG11 alleles carrying the mutations leading to the Y132F and K143R substitutions on a low copy number episomal plasmid in Saccharomyces cerevisiae revealed that both mutations increase fluconazole resistance, but the specific contribution of these mutations to triazole resistance in C. auris has not been defined (14).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [14] Healey KR, Kordalewska M, Jimenez Ortigosa C, Singh A, Berrio I, Chowdhary A, Perlin DS. 2018. Limited ERG11 mutations identified in isolates of Candida auris directly contribute to reduced azole susceptibility. Antimicrob Agents Chemother 62: e01427. doi: 10.1128/AAC.01427-18. PMC6153782 30082281 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    All three ERG11 mutations contribute to fluconazole resistance, but none alone are sufficient to confer clinical resistance.

    “While all three of these mutations contribute to fluconazole resistance, none alone are sufficient to confer clinical resistance.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Only three predominant mutations in C. auris ERG11 have been identified, encoding the amino acid substitutions VF125AL, Y132F, and K143R, and each is strongly associated with specific genetic clades of C. auris.

    “Intriguingly, only three predominant mutations in ERG11 have been identified, encoding the amino acid substitutions VF125AL (more commonly reported simply as F126L), Y132F, and K143R, and each of these mutations is strongly associated with specific genetic clades of C. auris (9).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [9] Lockhart SR, Etienne KA, Vallabhaneni S, Farooqi J, Chowdhary A, Govender NP, Colombo AL, Calvo B, Cuomo CA, Desjardins CA, Berkow EL, Castanheira M, Magobo RE, Jabeen K, Asghar RJ, Meis JF, Jackson B, Chiller T, Litvintseva AP. 2017. simultaneous emergence of multidrug-resistant Candida auris on 3 continents confirmed by whole-genome sequencing and epidemiological analyses. Clin Infect Dis 64: 134– 140. doi: 10.1093/cid/ciw691. 27988485 PMC5215215 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Inhibition of sterol-demethylase by triazoles depletes cellular ergosterol and leads to accumulation of other sterol precursors, including those thought to be toxic to the fungal cell.

    “Ergosterol is the prominent membrane sterol among most pathogenic fungi, and inhibition of sterol-demethylase by the triazoles depletes cellular ergosterol and leads to the accumulation of other sterol precursors, including those thought to be toxic to the fungal cell.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [19] Kelly SL, Lamb DC, Corran AJ, Baldwin BC, Kelly DE. 1995. Mode of action and resistance to azole antifungals associated with the formation of 14 alpha-methylergosta-8,24(28)-dien-3 beta,6 alpha-diol. Biochem Biophys Res Commun 207: 910– 915. doi: 10.1006/bbrc.1995.1272. 7864896 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The K143 position resides in a region proximal to the heme presumed to be involved in electron transfer from the P450 reductase and the K143R substitution affects catalytic efficiency.

    “The K143 position resides in a region proximal to the heme presumed to be involved in electron transfer from the P450 reductase and the K143R substitution affects catalytic efficiency (4).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [4] Warrilow AG, Nishimoto AT, Parker JE, Price CL, Flowers SA, Kelly DE, Rogers PD, Kelly SL. 2019. The evolution of azole resistance in Candida albicans sterol 14alpha-demethylase (CYP51) through incremental amino acid substitutions. Antimicrob Agents Chemother 63. doi: 10.1128/AAC.02586-18. PMC6496074 30783005 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    A single mutation resulting in the F126L substitution was found in a highly fluconazole-resistant C. albicans clinical isolate in conjunction with mutations encoding E266D, S405F, and V437I.

    “However, a single mutation resulting in the F126L substitution was found in a highly fluconazole-resistant C. albicans clinical isolate in conjunction with mutations encoding the E266D, S405F, and V437I substitutions (20).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [20] Marichal P, Koymans L, Willemsens S, Bellens D, Verhasselt P, Luyten W, Borgers M, Ramaekers FCS, Odds FC, Vanden Bossche H. 1999. Contribution of mutations in the cytochrome P450 14alpha-demethylase (Erg11p, Cyp51p) to azole resistance in Candida albicans. Microbio 145: 2701– 2713. doi: 10.1099/00221287-145-10-2701. 10537192 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The triazoles account for more than 80% of all antifungal prescribing in the United States.

    “The triazoles are the most commonly relied upon class of antifungals worldwide, accounting for more than 80% of all antifungal prescribing in the United States (18).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [18] Vallabhaneni S, Baggs J, Tsay S, Srinivasan AR, Jernigan JA, Jackson BR. 2018. Trends in antifungal use in US hospitals, 2006–12. J Antimicrob Chemother 73: 2867– 2875. doi: 10.1093/jac/dky270. 30295769 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The F126 residue is predicted to reside near the ligand access channel and modifications to this residue may interfere with the binding of sterol-demethylase inhibitors.

    “While the potential contribution to triazole resistance of this F126L-encoding mutation in C. albicans has not been delineated, the F126 residue is predicted to reside near the ligand access channel and modifications to this residue may interfere with the binding of sterol-demethylase inhibitors (20).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [20] Marichal P, Koymans L, Willemsens S, Bellens D, Verhasselt P, Luyten W, Borgers M, Ramaekers FCS, Odds FC, Vanden Bossche H. 1999. Contribution of mutations in the cytochrome P450 14alpha-demethylase (Erg11p, Cyp51p) to azole resistance in Candida albicans. Microbio 145: 2701– 2713. doi: 10.1099/00221287-145-10-2701. 10537192 source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation

    The triazoles exert antifungal activity through competitive inhibition of sterol-demethylase, which catalyzes a critical and rate-limiting step in ergosterol biosynthesis.

    “The triazoles exert antifungal activity through the competitive inhibition of sterol-demethylase, which catalyzes a critical and rate-limiting step in the ergosterol biosynthesis pathway (19).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [19] Kelly SL, Lamb DC, Corran AJ, Baldwin BC, Kelly DE. 1995. Mode of action and resistance to azole antifungals associated with the formation of 14 alpha-methylergosta-8,24(28)-dien-3 beta,6 alpha-diol. Biochem Biophys Res Commun 207: 910– 915. doi: 10.1006/bbrc.1995.1272. 7864896 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    In C. albicans, the Y132F substitution resulted in an 8-fold increase in fluconazole MIC, the K143R substitution resulted in a 16-fold increase, both affected voriconazole MIC 2-fold, K143R increased itraconazole MIC 2-fold, and neither affected posaconazole susceptibility.

    “In C. albicans the Y132F substitution resulted in an 8-fold increase in fluconazole MIC whereas the K143R substitution resulted in a 16-fold increase. Both affected voriconazole MIC to a lesser extent (2-fold increase), the K143R substitution increased itraconazole MIC 2-fold, and neither had an effect on posaconazole susceptibility (5).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [5] Flowers SA, Colon B, Whaley SG, Schuler MA, Rogers PD. 2015. Contribution of clinically derived mutations in ERG11 to azole resistance in Candida albicans. Antimicrob Agents Chemother 59: 450– 460. doi: 10.1128/AAC.03470-14. 25385095 PMC4291385 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The Y132 position is within the predicted catalytic site of sterol-demethylase and the Y132F substitution is predicted to interfere with fluconazole binding.

    “The Y132 position is within the predicted catalytic site of sterol-demethylase and the Y132F substitution is predicted to interfere with fluconazole binding.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [4] Warrilow AG, Nishimoto AT, Parker JE, Price CL, Flowers SA, Kelly DE, Rogers PD, Kelly SL. 2019. The evolution of azole resistance in Candida albicans sterol 14alpha-demethylase (CYP51) through incremental amino acid substitutions. Antimicrob Agents Chemother 63. doi: 10.1128/AAC.02586-18. PMC6496074 30783005 source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductcitation

    MIC determination was performed by broth microdilution in biological duplicate, each with three technical replicates, and MIC from biological replicates were in agreement.

    “A modified CLSI MIC determination employing the standard endpoint of 50% growth inhibition was performed using broth microdilution in biological duplicate, each with three technical replicates, as previously described, and MIC from biological replicates were in agreement (15).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [15] Rybak JM, Munoz JF, Barker KS, Parker JE, Esquivel BD, Berkow EL, Lockhart SR, Gade L, Palmer GE, White TC, Kelly SL, Cuomo CA, Rogers PD. 2020. Mutations in TAC1B: a novel genetic determinant of clinical fluconazole resistance in Candida auris. mBio 11: e00365. doi: 10.1128/mBio.00365-20. 32398311 PMC7218281 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The CDC found the modal MIC of all C. auris isolates from the United States to be at least 256 mg/L, with 90% of isolates possessing fluconazole MIC at least 32 mg/L.

    “Testing hundreds of clinical C. auris clinical isolates, the Center for Disease Control and Prevention (CDC) has found the modal MIC of all C. auris isolates from the United States to be ≥256 mg/L with 90% of isolates possessing fluconazole MIC ≥32 mg/L (the tentative clinical breakpoint set forth by the CDC) (11).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [11] Centers for Disease Control and Prevention. 2020. Antifungal Susceptibility Testing and Interpretation. https://www.cdc.gov/fungal/candida-auris/c-auris-antifungal.html. Accessed August 31, 2021.

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    In C. albicans, mutations in ERG11 often accompany activating mutations in UPC2, which leads to increased expression of ergosterol biosynthesis genes including ERG11 and has a combinatorial effect on triazole susceptibility.

    “In C. albicans, mutations in ERG11 often accompany activating mutations in UPC2 which encodes the major transcriptional regulator of ergosterol biosynthesis (5). Such activation of UPC2 leads to increased expression of genes of the ergosterol biosynthesis pathway including ERG11 which in combination with ERG11 mutations has a combinatorial effect on triazole susceptibility (5, 21, 22).”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [5] Flowers SA, Colon B, Whaley SG, Schuler MA, Rogers PD. 2015. Contribution of clinically derived mutations in ERG11 to azole resistance in Candida albicans. Antimicrob Agents Chemother 59: 450– 460. doi: 10.1128/AAC.03470-14. 25385095 PMC4291385 source

      Not checked in the free run.

    • cites [21] Dunkel N, Liu TT, Barker KS, Homayouni R, Morschhauser J, Rogers PD. 2008. A gain-of-function mutation in the transcription factor Upc2p causes upregulation of ergosterol biosynthesis genes and increased fluconazole resistance in a clinical Candida albicans isolate. Eukaryot Cell 7: 1180– 1190. doi: 10.1128/EC.00103-08. 18487346 PMC2446669 source

      Not checked in the free run.

    • cites [22] Flowers SA, Barker KS, Berkow EL, Toner G, Chadwick SG, Gygax SE, Morschhauser J, Rogers PD. 2012. Gain-of-function mutations in UPC2 are a frequent cause of ERG11 upregulation in azole-resistant clinical isolates of Candida albicans. Eukaryot Cell 11: 1289– 1299. doi: 10.1128/EC.00215-12. 22923048 PMC3485914 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    In C. albicans, the majority of fluconazole resistance-associated ERG11 mutations are found within three hot spot regions corresponding to amino acids 105 to 165, 266 to 287, and 405 to 488.

    “Among pathogenic fungi, the role of mutations in the gene encoding sterol-demethylase in antifungal resistance has been most comprehensively studied in C. albicans, where a wide repertoire of mutations have been observed among fluconazole-resistant isolates, the majority of which are found within three hot spot regions corresponding to amino acids 105 to 165, 266 to 287, and 405 to 488 (4, 5).”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [4] Warrilow AG, Nishimoto AT, Parker JE, Price CL, Flowers SA, Kelly DE, Rogers PD, Kelly SL. 2019. The evolution of azole resistance in Candida albicans sterol 14alpha-demethylase (CYP51) through incremental amino acid substitutions. Antimicrob Agents Chemother 63. doi: 10.1128/AAC.02586-18. PMC6496074 30783005 source

      Not checked in the free run.

    • cites [5] Flowers SA, Colon B, Whaley SG, Schuler MA, Rogers PD. 2015. Contribution of clinically derived mutations in ERG11 to azole resistance in Candida albicans. Antimicrob Agents Chemother 59: 450– 460. doi: 10.1128/AAC.03470-14. 25385095 PMC4291385 source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductcitation

    Transformants were confirmed to possess a single copy of ERG11 by qPCR.

    “Additionally, transformants were confirmed to possess a single copy of ERG11 by qPCR as previously described (15).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [15] Rybak JM, Munoz JF, Barker KS, Parker JE, Esquivel BD, Berkow EL, Lockhart SR, Gade L, Palmer GE, White TC, Kelly SL, Cuomo CA, Rogers PD. 2020. Mutations in TAC1B: a novel genetic determinant of clinical fluconazole resistance in Candida auris. mBio 11: e00365. doi: 10.1128/mBio.00365-20. 32398311 PMC7218281 source

      Not checked in the free run.

22 of 22

  • The paper relies on this without support.

    Nearly all fluconazole-resistant C. auris clinical isolates possess mutations in ERG11.

    “Almost all fluconazole-resistant clinical isolates have been reported to possess mutations in ERG11 (B9J08_001448), the C. auris gene encoding sterol-demethylase.”

  • The paper relies on this without support.

    The three C. auris ERG11 mutations studied alter residues at or near the catalytic domain of Erg11.

    “As the three C. auris ERG11 mutations studied in this work alter residues predicted to be at or near the catalytic domain of Erg11, these additional interactions along the ligand access channel may contribute to the maintained activity of isavuconazole, itraconazole, and posaconazole.”

  • The paper relies on this without support.

    The lipophilic side chains of isavuconazole, itraconazole, and posaconazole interact with sterol-demethylase at additional residues along the enzyme ligand access channel.

    “Unlike fluconazole and voriconazole, the lipophilic side chains of all three of these triazoles are believed to interact with the sterol-demethylase enzyme at additional residues along the enzyme ligand access channel.”
3 of 3

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?

  • Mutations in ERG11 contribute to reduced azole susceptibility in C. auris.

    “Mutations in ERG11 also contribute to reduced azole susceptibility in the emerging fungal pathogen C. auris12–15, with a recent study highlighting a previously unreported substitution in Erg11 (F444L) identified in azole-resistant clade IV clinical isolates that has not been previously described in other reports15.”

    From Molecular mechanisms governing antifungal drug resistance (2023) · cites this paper as [14]

Self-check

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

Each contradiction between two passages listed here was confirmed by an independent check.

  • Voriconazole increase reported as both 8-16-fold and 4-16-fold

    Minor

    The abstract says each introduced mutant allele increased voriconazole MIC by at least 8-fold, whereas the Results report a range starting at 4-fold. Table 1 supports the smaller increase for the K143R strain (≤0.004 to 0.015 mg/L).

1 of 1

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Authors
Rybak, J. M., Sharma, C., Doorley, L. A., Barker, K. S., Palmer, G. E., & Rogers, P. D.
Affiliations
  • St. Jude Children's Research Hospital (US)
  • University of Tennessee Health Science Center (US)
Corresponding author
Rogers, P. David
ORCID
Venue
Microbiology Spectrum
Publisher
American Society for Microbiology
Published
2021-12-22
Volume
9
Issue
3
Pages
e0158521-e0158521
ISSN
2165-0497 (ISSN-L)
DOI
10.1128/spectrum.01585-21
PMC
PMC8653815
OpenAlex
W4200400419
Semantic Scholar
95263d4899af8cb9292e29b60a8381c59ef87be2
Cited by
69
References
20
Citations by year
2026: 13 · 2025: 15 · 2024: 19 · 2023: 16 · 2022: 6
FWCI
3.24
Type
journal article
Language
en
Open access
Licence
Locations
  • Microbiology Spectrum (publishedVersion, cc-by)
  • PubMed Central (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
Funders
HHS | NIH | National Institute of Allergy and Infectious Diseases (R01 A1058145)
Topics
  • Health Sciences › Medicine › Infectious Diseases › Antifungal resistance and susceptibility
  • Life Sciences › Agricultural and Biological Sciences › Ecology, Evolution, Behavior and Systematics › Fungal Plant Pathogen Control
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Fungal and yeast genetics research
Keywords
Candida auris, ERG11 mutations, triazole resistance, fluconazole resistance, antifungal susceptibility, triazole antifungals, drug resistance mechanisms
MeSH terms
Candida auris, Antifungal Agents, Candidiasis, Cytochrome P-450 Enzyme System, Fungal Proteins, Humans, Microbial Sensitivity Tests, Mutation, Triazoles, Fluconazole, Amino Acid Substitution, Drug Resistance, Fungal

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Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-09.

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