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Saha D, Gregor JB, Hoda S, Eastman KE, Navarrete M, Wisecaver JH, Briggs SD. Candida glabrata maintains two Hap1 homologs, Zcf27 and Zcf4, for distinct roles in ergosterol gene regulation to mediate sterol homeostasis under azole and hypoxic conditions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.20.599910. [PMID: 38979343 PMCID: PMC11230168 DOI: 10.1101/2024.06.20.599910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Candida glabrata exhibits innate resistance to azole antifungal drugs but also has the propensity to rapidly develop clinical drug resistance. Azole drugs, which target Erg11, is one of the three major classes of antifungals used to treat Candida infections. Despite their widespread use, the mechanism controlling azole-induced ERG gene expression and drug resistance in C. glabrata has primarily revolved around Upc2 and/or Pdr1. In this study, we determined the function of two zinc cluster transcription factors, Zcf27 and Zcf4, as direct but distinct regulators of ERG genes. Our phylogenetic analysis revealed C. glabrata Zcf27 and Zcf4 as the closest homologs to Saccharomyces cerevisiae Hap1. Hap1 is a known zinc cluster transcription factor in S. cerevisiae in controlling ERG gene expression under aerobic and hypoxic conditions. Interestingly, when we deleted HAP1 or ZCF27 in either S. cerevisiae or C. glabrata, respectively, both deletion strains showed altered susceptibility to azole drugs, whereas the strain deleted for ZCF4 did not exhibit azole susceptibility. We also determined that the increased azole susceptibility in a zcf27Δ strain is attributed to decreased azole-induced expression of ERG genes, resulting in decreased levels of total ergosterol. Surprisingly, Zcf4 protein expression is barely detected under aerobic conditions but is specifically induced under hypoxic conditions. However, under hypoxic conditions, Zcf4 but not Zcf27 was directly required for the repression of ERG genes. This study provides the first demonstration that Zcf27 and Zcf4 have evolved to serve distinct roles allowing C. glabrata to adapt to specific host and environmental conditions. IMPORTANCE Invasive and drug-resistant fungal infections pose a significant public health concern. Candida glabrata , a human fungal pathogen, is often difficult to treat due to its intrinsic resistance to azole antifungal drugs and its capacity to develop clinical drug resistance. Therefore, understanding the pathways that facilitate fungal growth and environmental adaptation may lead to novel drug targets and/or more efficacious antifungal therapies. While the mechanisms of azole resistance in Candida species have been extensively studied, the roles of zinc cluster transcription factors, such as Zcf27 and Zcf4, in C. glabrata have remained largely unexplored until now. Our research shows that these factors play distinct yet crucial roles in regulating ergosterol homeostasis under azole drug treatment and oxygen-limiting growth conditions. These findings offer new insights into how this pathogen adapts to different environmental conditions and enhances our understanding of factors that alter drug susceptibility and/or resistance.
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Conway TP, Simonicova L, Moye-Rowley WS. Overlapping coactivator function is required for transcriptional activation by the Candida glabrata Pdr1 transcription factor. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.24.595833. [PMID: 38853834 PMCID: PMC11160619 DOI: 10.1101/2024.05.24.595833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Azole resistance in the pathogenic yeast Candida glabrata is a serious clinical complication and increasing in frequency. The majority of resistant organisms have been found to contain a substitution mutation in the Zn2Cys6 zinc cluster-containing transcription factor Pdr1. These mutations typically lead to this factor driving high, constitutive expression of target genes like the ATP-binding cassette transporter-encoding gene CDR1 . Overexpression of Cdr1 is required for the observed elevated fluconazole resistance exhibited by strains containing one of these hyperactive PDR1 alleles. While the identity of hyperactive PDR1 alleles has been extensively documented, the mechanisms underlying how these gain-of-function (GOF) forms of Pdr1 lead to elevated target gene transcription are not well understood. We have used a tandem affinity purification (TAP)-tagged form of Pdr1 to identify coactivator proteins that biochemically purify with the wild-type and two different GOF forms of Pdr1. Three coactivator proteins were found to associate with Pdr1: the SWI/SNF complex Snf2 chromatin remodeling protein and two different components of the SAGA complex, Spt7 and Ngg1. We found that deletion mutants lacking either SNF2 or SPT7 exhibited growth defects, even in the absence of fluconazole challenge. To overcome these issues, we employed a conditional degradation system to acutely deplete these coactivators and determined that loss of either coactivator complex, SWI/SNF or SAGA, caused defects in Pdr1-dependent transcription. A double degron strain that could be depleted for both SWI/SNF and SAGA exhibited a profound defect in PDR1 autoregulation, revealing that these complexes work together to ensure high level Pdr1-dependent gene transcription.
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Li J, Aubry L, Brandalise D, Coste AT, Sanglard D, Lamoth F. Upc2-mediated mechanisms of azole resistance in Candida auris. Microbiol Spectr 2024; 12:e0352623. [PMID: 38206035 PMCID: PMC10845950 DOI: 10.1128/spectrum.03526-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 12/13/2023] [Indexed: 01/12/2024] Open
Abstract
Candida auris is an emerging yeast pathogen of major concern because of its ability to cause hospital outbreaks of invasive candidiasis and to develop resistance to antifungal drugs. A majority of C. auris isolates are resistant to fluconazole, an azole drug used for the treatment of invasive candidiasis. Mechanisms of azole resistance are multiple, including mutations in the target gene ERG11 and activation of the transcription factors Tac1b and Mrr1, which control the drug transporters Cdr1 and Mdr1, respectively. We investigated the role of the transcription factor Upc2, which is known to regulate the ergosterol biosynthesis pathway and azole resistance in other Candida spp. Genetic deletion and hyperactivation of Upc2 by epitope tagging in C. auris resulted in drastic increases and decreases in susceptibility to azoles, respectively. This effect was conserved in strains with genetic hyperactivation of Tac1b or Mrr1. Reverse transcription PCR analyses showed that Upc2 regulates ERG11 expression and also activates the Mrr1/Mdr1 pathway. We showed that upregulation of MDR1 by Upc2 could occur independently from Mrr1. The impact of UPC2 deletion on MDR1 expression and azole susceptibility in a hyperactive Mrr1 background was stronger than that of MRR1 deletion in a hyperactive Upc2 background. While Upc2 hyperactivation resulted in a significant increase in the expression of TAC1b, CDR1 expression remained unchanged. Taken together, our results showed that Upc2 is crucial for azole resistance in C. auris, via regulation of the ergosterol biosynthesis pathway and activation of the Mrr1/Mdr1 pathway. Notably, Upc2 is a very potent and direct activator of Mdr1.IMPORTANCECandida auris is a yeast of major medical importance causing nosocomial outbreaks of invasive candidiasis. Its ability to develop resistance to antifungal drugs, in particular to azoles (e.g., fluconazole), is concerning. Understanding the mechanisms of azole resistance in C. auris is important and may help in identifying novel antifungal targets. This study shows the key role of the transcription factor Upc2 in azole resistance of C. auris and shows that this effect is mediated via different pathways, including the regulation of ergosterol biosynthesis and also the direct upregulation of the drug transporter Mdr1.
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Affiliation(s)
- Jizhou Li
- Department of Laboratory Medicine and Pathology, Institute of Microbiology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
- Infectious Diseases Service, Department of Medicine, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Lola Aubry
- Department of Laboratory Medicine and Pathology, Institute of Microbiology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Danielle Brandalise
- Department of Laboratory Medicine and Pathology, Institute of Microbiology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Alix T. Coste
- Department of Laboratory Medicine and Pathology, Institute of Microbiology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Dominique Sanglard
- Department of Laboratory Medicine and Pathology, Institute of Microbiology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
| | - Frederic Lamoth
- Department of Laboratory Medicine and Pathology, Institute of Microbiology, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
- Infectious Diseases Service, Department of Medicine, Lausanne University Hospital, University of Lausanne, Lausanne, Switzerland
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Hervay NT, Elias D, Habova M, Jacko J, Morvova M, Gbelska Y. Catechin potentiates the antifungal effect of miconazole in Candida glabrata. Folia Microbiol (Praha) 2023; 68:835-842. [PMID: 37145224 PMCID: PMC10689516 DOI: 10.1007/s12223-023-01061-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 04/25/2023] [Indexed: 05/06/2023]
Abstract
The rising number of invasive fungal infections caused by drug-resistant Candida strains is one of the greatest challenges for the development of novel antifungal strategies. The scarcity of available antifungals has drawn attention to the potential of natural products as antifungals and in combinational therapies. One of these is catechins-polyphenolic compounds-flavanols, found in a variety of plants. In this work, we evaluated the changes in the susceptibility of Candida glabrata strain characterized at the laboratory level and clinical isolates using the combination of catechin and antifungal azoles. Catechin alone had no antifungal activity within the concentration range tested. Its use in combination with miconazole resulted in complete inhibition of growth in the sensitive C. glabrata isolate and a significant growth reduction in the azole resistant C. glabrata clinical isolate. Simultaneous use of catechin and miconazole leads to increased intracellular ROS generation. The enhanced susceptibility of C. glabrata clinical isolates to miconazole by catechin was accompanied with the intracellular accumulation of ROS and changes in the plasma membrane permeability, as measured using fluorescence anisotropy, affecting the function of plasma membrane proteins.
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Affiliation(s)
- Nora Tóth Hervay
- Faculty of Natural Sciences, Department of Microbiology and Virology, Comenius University in Bratislava, Ilkovicova 6, Bratislava, 842 15, Slovak Republic
| | - Daniel Elias
- Faculty of Natural Sciences, Department of Microbiology and Virology, Comenius University in Bratislava, Ilkovicova 6, Bratislava, 842 15, Slovak Republic
| | - Marcela Habova
- Faculty of Natural Sciences, Department of Microbiology and Virology, Comenius University in Bratislava, Ilkovicova 6, Bratislava, 842 15, Slovak Republic
| | - Juraj Jacko
- Faculty of Mathematics, Physics and Informatics, Department of Nuclear Physics and Biophysics, Comenius University in Bratislava, Mlynska Dolina, Bratislava, 842 48, Slovak Republic
| | - Marcela Morvova
- Faculty of Mathematics, Physics and Informatics, Department of Nuclear Physics and Biophysics, Comenius University in Bratislava, Mlynska Dolina, Bratislava, 842 48, Slovak Republic
| | - Yvetta Gbelska
- Faculty of Natural Sciences, Department of Microbiology and Virology, Comenius University in Bratislava, Ilkovicova 6, Bratislava, 842 15, Slovak Republic.
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Boyce KJ. The Microevolution of Antifungal Drug Resistance in Pathogenic Fungi. Microorganisms 2023; 11:2757. [PMID: 38004768 PMCID: PMC10673521 DOI: 10.3390/microorganisms11112757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 10/30/2023] [Accepted: 10/30/2023] [Indexed: 11/26/2023] Open
Abstract
The mortality rates of invasive fungal infections remain high because of the limited number of antifungal drugs available and antifungal drug resistance, which can rapidly evolve during treatment. Mutations in key resistance genes such as ERG11 were postulated to be the predominant cause of antifungal drug resistance in the clinic. However, recent advances in whole genome sequencing have revealed that there are multiple mechanisms leading to the microevolution of resistance. In many fungal species, resistance can emerge through ERG11-independent mechanisms and through the accumulation of mutations in many genes to generate a polygenic resistance phenotype. In addition, genome sequencing has revealed that full or partial aneuploidy commonly occurs in clinical or microevolved in vitro isolates to confer antifungal resistance. This review will provide an overview of the mutations known to be selected during the adaptive microevolution of antifungal drug resistance and focus on how recent advances in genome sequencing technology have enhanced our understanding of this process.
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Affiliation(s)
- Kylie J Boyce
- School of Science, RMIT University, Melbourne, VIC 3085, Australia
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Ghasemi R, Lotfali E, Rezaei K, Madinehzad SA, Tafti MF, Aliabadi N, Kouhsari E, Fattahi M. Meyerozyma guilliermondii species complex: review of current epidemiology, antifungal resistance, and mechanisms. Braz J Microbiol 2022; 53:1761-1779. [PMID: 36306113 PMCID: PMC9679122 DOI: 10.1007/s42770-022-00813-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 06/30/2022] [Indexed: 01/13/2023] Open
Abstract
Meyerozyma guilliermondii has been accepted as a complex composed of Meyerozyma guilliermondii, Meyerozyma carpophila, and Meyerozyma caribbica. M. guilliermondii is a saprophyte detected on human mucosa and skin. It can lead to serious infections in patients with risk factors like chemotherapy, immunodeficiency, gastrointestinal or cardiovascular surgery, and oncology disorders. Most deaths related to M. guilliermondii infections occur in individuals with malignancy. In recent decades, incidence of M. guilliermondii infections is increased. Sensitivity of this microorganism to conventional antifungals (e.g., amphotericin B, fluconazole, micafungin and anidulafungin) was reduced. Prophylactic and empirical uses of these drugs are linked to elevated minimal inhibitory concentrations (MICs) of M. guilliermondii. Drug resistance has concerned many researchers across the world. They are attempting to discover appropriate solution to combat this challenge. This study reviews the most important mechanisms of resistance to antifungals developed by in M. guilliermondii species complex.
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Affiliation(s)
- Reza Ghasemi
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ensieh Lotfali
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Kamran Rezaei
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Seyed Ataollah Madinehzad
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mahdi Falah Tafti
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Nikta Aliabadi
- Microbiology Department Islamic, Azad University Tehran Branch, Tehran, Iran
| | - Ebrahim Kouhsari
- Department of Laboratory Sciences, Faculty of Paramedicine, Golestan University of Medical Sciences, Gorgan, Iran
- Laboratory Sciences Research Center, Golestan University of Medical Sciences, Gorgan, Iran
| | - Mahsa Fattahi
- Center for Research and Training in Skin Diseases and Leprosy, Tehran University of Medical Sciences, Tehran, Iran.
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7
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Rogers PD. Sterol homeostasis in yeast. Nat Chem Biol 2022; 18:1170-1171. [PMID: 36229682 DOI: 10.1038/s41589-022-01143-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- P David Rogers
- Department of Pharmacy and Pharmaceutical Sciences, St. Jude Children's Research Hospital, Memphis, TN, USA.
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8
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Bhakt P, Raney M, Kaur R. The SET-domain protein CgSet4 negatively regulates antifungal drug resistance via the ergosterol biosynthesis transcriptional regulator CgUpc2a. J Biol Chem 2022; 298:102485. [PMID: 36108742 PMCID: PMC9576903 DOI: 10.1016/j.jbc.2022.102485] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 08/30/2022] [Accepted: 09/02/2022] [Indexed: 11/27/2022] Open
Abstract
Invasive fungal infections, which pose a serious threat to human health, are increasingly associated with a high mortality rate and elevated health care costs, owing to rising resistance to current antifungals and emergence of multidrug-resistant fungal species. Candida glabrata is the second to fourth common cause of Candida bloodstream infections. Its high propensity to acquire resistance toward two mainstream drugs, azoles (inhibit ergosterol biosynthesis) and echinocandins (target cell wall), in clinical settings, and its inherent low azole susceptibility render antifungal therapy unsuccessful in many cases. Here, we demonstrate a pivotal role for the SET {suppressor of variegation 3 to 9 [Su(var)3-9], enhancer of zeste [E(z)], and trithorax (Trx)} domain-containing protein, CgSet4, in azole and echinocandin resistance via negative regulation of multidrug transporter-encoding and ergosterol biosynthesis (ERG) genes through the master transcriptional factors CgPdr1 and CgUpc2A, respectively. RNA-Seq analysis revealed that C. glabrata responds to caspofungin (CSP; echinocandin antifungal) stress by downregulation and upregulation of ERG and cell wall organization genes, respectively. Although CgSet4 acts as a repressor of the ergosterol biosynthesis pathway via CgUPC2A transcriptional downregulation, the CSP-induced ERG gene repression is not dependent on CgSet4, as CgSet4 showed diminished abundance on the CgUPC2A promoter in CSP-treated cells. Furthermore, we show a role for the last three enzymes of the ergosterol biosynthesis pathway, CgErg3, CgErg5, and CgErg4, in antifungal susceptibility and virulence in C. glabrata. Altogether, our results unveil the link between ergosterol biosynthesis and echinocandin resistance and have implications for combination antifungal therapy.
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Affiliation(s)
- Priyanka Bhakt
- Laboratory of Fungal Pathogenesis, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India
| | - Mayur Raney
- Laboratory of Fungal Pathogenesis, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India; Graduate Studies, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Rupinder Kaur
- Laboratory of Fungal Pathogenesis, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India.
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9
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Gaspar-Cordeiro A, Amaral C, Pobre V, Antunes W, Petronilho A, Paixão P, Matos AP, Pimentel C. Copper Acts Synergistically With Fluconazole in Candida glabrata by Compromising Drug Efflux, Sterol Metabolism, and Zinc Homeostasis. Front Microbiol 2022; 13:920574. [PMID: 35774458 PMCID: PMC9237516 DOI: 10.3389/fmicb.2022.920574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 05/23/2022] [Indexed: 11/18/2022] Open
Abstract
The synergistic combinations of drugs are promising strategies to boost the effectiveness of current antifungals and thus prevent the emergence of resistance. In this work, we show that copper and the antifungal fluconazole act synergistically against Candida glabrata, an opportunistic pathogenic yeast intrinsically tolerant to fluconazole. Analyses of the transcriptomic profile of C. glabrata after the combination of copper and fluconazole showed that the expression of the multidrug transporter gene CDR1 was decreased, suggesting that fluconazole efflux could be affected. In agreement, we observed that copper inhibits the transactivation of Pdr1, the transcription regulator of multidrug transporters and leads to the intracellular accumulation of fluconazole. Copper also decreases the transcriptional induction of ergosterol biosynthesis (ERG) genes by fluconazole, which culminates in the accumulation of toxic sterols. Co-treatment of cells with copper and fluconazole should affect the function of proteins located in the plasma membrane, as several ultrastructural alterations, including irregular cell wall and plasma membrane and loss of cell wall integrity, were observed. Finally, we show that the combination of copper and fluconazole downregulates the expression of the gene encoding the zinc-responsive transcription regulator Zap1, which possibly, together with the membrane transporters malfunction, generates zinc depletion. Supplementation with zinc reverts the toxic effect of combining copper with fluconazole, underscoring the importance of this metal in the observed synergistic effect. Overall, this work, while unveiling the molecular basis that supports the use of copper to enhance the effectiveness of fluconazole, paves the way for the development of new metal-based antifungal strategies.
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Affiliation(s)
- Ana Gaspar-Cordeiro
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Catarina Amaral
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Vânia Pobre
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Wilson Antunes
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- Centro de Investigação da Academia Militar (CINAMIL), Unidade Militar Laboratorial de Defesa Biológica e Química (UMLDBQ), Lisbon, Portugal
| | - Ana Petronilho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Paulo Paixão
- Unidade de Infeção, Faculdade de Ciências Médicas, Chronic Diseases Research Centre – CEDOC, NOVA Medical School, Universidade NOVA de Lisboa, Lisbon, Portugal
- Laboratório de Patologia Clínica – SYNLAB, Hospital da Luz, Lisbon, Portugal
| | - António P. Matos
- Egas Moniz Interdisciplinary Research Centre, Egas Moniz Higher Education Cooperative, Caparica, Portugal
| | - Catarina Pimentel
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- *Correspondence: Catarina Pimentel,
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10
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Baker KM, Hoda S, Saha D, Gregor JB, Georgescu L, Serratore ND, Zhang Y, Cheng L, Lanman NA, Briggs SD. The Set1 Histone H3K4 Methyltransferase Contributes to Azole Susceptibility in a Species-Specific Manner by Differentially Altering the Expression of Drug Efflux Pumps and the Ergosterol Gene Pathway. Antimicrob Agents Chemother 2022; 66:e0225021. [PMID: 35471041 PMCID: PMC9112889 DOI: 10.1128/aac.02250-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Fungal infections are a major health concern because of limited antifungal drugs and development of drug resistance. Candida can develop azole drug resistance by overexpression of drug efflux pumps or mutating ERG11, the target of azoles. However, the role of epigenetic histone modifications in azole-induced gene expression and drug resistance is poorly understood in Candida glabrata. In this study, we show that Set1 mediates histone H3K4 methylation in C. glabrata. In addition, loss of SET1 and histone H3K4 methylation increases azole susceptibility in both C. glabrata and S. cerevisiae. This increase in azole susceptibility in S. cerevisiae and C. glabrata strains lacking SET1 is due to distinct mechanisms. For S. cerevisiae, loss of SET1 decreased the expression and function of the efflux pump Pdr5, but not ERG11 expression under azole treatment. In contrast, loss of SET1 in C. glabrata does not alter expression or function of efflux pumps. However, RNA sequencing revealed that C. glabrata Set1 is necessary for azole-induced expression of all 12 genes in the late ergosterol biosynthesis pathway, including ERG11 and ERG3. Furthermore, chromatin immunoprecipitation analysis shows histone H3K4 trimethylation increases upon azole-induced ERG gene expression. In addition, high performance liquid chromatography analysis indicated Set1 is necessary for maintaining proper ergosterol levels under azole treatment. Clinical isolates lacking SET1 were also hypersusceptible to azoles which is attributed to reduced ERG11 expression but not defects in drug efflux. Overall, Set1 contributes to azole susceptibility in a species-specific manner by altering the expression and consequently disrupting pathways known for mediating drug resistance.
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Affiliation(s)
- Kortany M. Baker
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
| | - Smriti Hoda
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
| | - Debasmita Saha
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
| | - Justin B. Gregor
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
| | - Livia Georgescu
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
| | - Nina D. Serratore
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
| | - Yueping Zhang
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
| | - Lizhi Cheng
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
| | - Nadia A. Lanman
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana, USA
- Department of Comparative Pathobiology, Purdue University, West Lafayette, Indiana, USA
| | - Scott D. Briggs
- Department of Biochemistry, Purdue University, West Lafayette, Indiana, USA
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana, USA
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11
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Ribeiro GF, Denes E, Heaney H, Childers DS. What 'Omics Can Tell Us About Antifungal Adaptation. FEMS Yeast Res 2021; 21:6484793. [PMID: 34958354 PMCID: PMC8755904 DOI: 10.1093/femsyr/foab070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 12/22/2021] [Indexed: 12/01/2022] Open
Abstract
Invasive candidiasis, the most frequent healthcare-associated invasive fungal infection, is commonly caused by Candida albicans. However, in recent years other antifungal-resistant Candida species—namely Candida glabrata and Candidaauris—have emerged as a serious matter of concern. Much of our understanding of the mechanisms regulating antifungal resistance and tolerance relies on studies utilizing C. albicans, C. glabrataand the model yeast Saccharomyces cerevisiae. ‘Omics studies have been used to describe alterations in metabolic, genomic and transcriptomic expression profiles upon antifungal treatment of fungal cells. The physiological changes identified by these approaches could significantly affect fungal fitness in the host and survival during antifungal challenge, as well as provide further understanding of clinical resistance. Thus, this review aims to comparatively address ‘omics data for C. albicans, C. glabrata andS. cerevisiae published from 2000 to 2021 to identify what these technologies can tell us regarding cellular responses to antifungal therapy. We will also highlight possible effects on pathogen survival and identify future avenues for antifungal research.
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Affiliation(s)
- Gabriela Fior Ribeiro
- University of Aberdeen, Institute of Medical Sciences, Aberdeen Fungal Group, Aberdeen, UK, AB25 2ZD
| | - Eszter Denes
- University of Aberdeen, Institute of Medical Sciences, Aberdeen Fungal Group, Aberdeen, UK, AB25 2ZD
| | - Helen Heaney
- University of Aberdeen, Institute of Medical Sciences, Aberdeen Fungal Group, Aberdeen, UK, AB25 2ZD
| | - Delma S Childers
- University of Aberdeen, Institute of Medical Sciences, Aberdeen Fungal Group, Aberdeen, UK, AB25 2ZD
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12
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Loss-of-Function ROX1 Mutations Suppress the Fluconazole Susceptibility of upc2AΔ Mutation in Candida glabrata, Implicating Additional Positive Regulators of Ergosterol Biosynthesis. mSphere 2021; 6:e0083021. [PMID: 34935446 PMCID: PMC8694151 DOI: 10.1128/msphere.00830-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two of the major classes of antifungal drugs in clinical use target ergosterol biosynthesis. Despite its importance, our understanding of the transcriptional regulation of ergosterol biosynthesis genes in pathogenic fungi is essentially limited to the role of hypoxia and sterol-stress-induced transcription factors such as Upc2 and Upc2A as well as homologs of sterol response element binding (SREB) factors. To identify additional regulators of ergosterol biosynthesis in Candida glabrata, an important human fungal pathogen with reduced susceptibility to ergosterol biosynthesis inhibitors relative to other Candida spp., we used a serial passaging strategy to isolate suppressors of the fluconazole hypersusceptibility of a upc2AΔ deletion mutant. This led to the identification of loss-of-function mutations in two genes: ROX1, the homolog of a hypoxia gene transcriptional suppressor in Saccharomyces cerevisiae, and CST6, a transcription factor that is involved in the regulation of carbon dioxide response in C. glabrata. Here, we describe a detailed analysis of the genetic interaction of ROX1 and UPC2A. In the presence of fluconazole, loss of Rox1 function restores ERG11 expression to the upc2AΔ mutant and inhibits the expression of ERG3 and ERG6, leading to increased levels of ergosterol and decreased levels of the toxic sterol 14α methyl-ergosta-8,24(28)-dien-3β, 6α-diol, relative to the upc2AΔ mutant. Our observations establish that Rox1 is a negative regulator of ERG gene biosynthesis and indicate that a least one additional positive transcriptional regulator of ERG gene biosynthesis must be present in C. glabrata. IMPORTANCECandida glabrata is one of the most important human fungal pathogens and has reduced susceptibility to azole-class inhibitors of ergosterol biosynthesis. Although ergosterol is the target of two of the three classes of antifungal drugs, relatively little is known about the regulation of this critical cellular pathway. Sterols are both essential components of the eukaryotic plasma membrane and potential toxins; therefore, sterol homeostasis is critical for cell function. Here, we identified two new negative regulators in C. glabrata of ergosterol (ERG) biosynthesis gene expression. Our results also indicate that in addition to Upc2A, the only known activator of ERG genes, additional positive regulators of this pathway must exist.
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Wang Q, Li Y, Cai X, Li R, Zheng B, Yang E, Liang T, Yang X, Wan Z, Liu W. Two Sequential Clinical Isolates of Candida glabrata with Multidrug-Resistance to Posaconazole and Echinocandins. Antibiotics (Basel) 2021; 10:antibiotics10101217. [PMID: 34680798 PMCID: PMC8532709 DOI: 10.3390/antibiotics10101217] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 09/28/2021] [Accepted: 10/02/2021] [Indexed: 12/17/2022] Open
Abstract
Candida glabrata is one of the most prevalent causative pathogens of invasive candidiasis, and multidrug-resistant strains are emerging. We identified two clinical isolates of C. glabrata, BMU10720 and BMU10722 sequentially isolated from one patient with multidrug-resistance to posaconazole (POS), caspofungin (CAS), micafungin (MCF), and anidulafungin (ANF). Overexpression of ERG11 in BMU10720 and CDR1 in BMU10722 were detected at basal level. When exposed to POS, CDR1 was significantly up-regulated in both isolates compared with susceptible reference strain, while ERG11 was up-regulated considerably only in BMU10720. PDR1 sequencing revealed that both isolates harbored P76S, P143T, and D243N substitutions, while ERG11 was intact. Cdr1 inhibitor FK520 reversed POS-resistance by down-regulating ERG11 expression. FKS sequencing revealed that both isolates harbored S663P substitution in FKS2, and four single nucleotide polymorphisms (SNPs) existed in FKS2 genes between BMU10720 and BMU10722, while FKS1 was intact. Both FKS1 and FKS2 were up-regulated by CAS in BMU10720 and BMU10722. FK520 down-regulated FKS2 expression induced by CAS through inhibiting calcineurin, resulting in synergic effect with echinocandins as well as Congo Red and Calcofluor White, two cell wall-perturbing agents. In conclusion, the multidrug-resistance of C. glabrata isolates in our study was conferred by different mechanisms. CDR1 and ERG11 overexpression in one isolate and only CDR1 overexpression in the other isolate may mediate POS-resistance. S663P mutation in FKS2 and up-regulation of FKS2 may contribute to echinocandin-resistance in both isolates.
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Affiliation(s)
- Qiqi Wang
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing 100034, China; (Q.W.); (R.L.); (T.L.); (X.Y.); (Z.W.)
- National Clinical Research Center for Skin and Immune Diseases, Beijing 100034, China
- Research Center for Medical Mycology, Peking University, Beijing 100034, China
- Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing 100034, China
| | - Yun Li
- Institute of Clinical Pharmacology, Peking University First Hospital, Beijing 100034, China; (Y.L.); (B.Z.)
| | - Xuan Cai
- Department of Clinical Laboratory, Renmin Hospital of Wuhan University, Wuhan 430060, China;
| | - Ruoyu Li
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing 100034, China; (Q.W.); (R.L.); (T.L.); (X.Y.); (Z.W.)
- National Clinical Research Center for Skin and Immune Diseases, Beijing 100034, China
- Research Center for Medical Mycology, Peking University, Beijing 100034, China
- Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing 100034, China
| | - Bo Zheng
- Institute of Clinical Pharmacology, Peking University First Hospital, Beijing 100034, China; (Y.L.); (B.Z.)
| | - Ence Yang
- Department of Microbiology & Infectious Disease Center, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China;
| | - Tianyu Liang
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing 100034, China; (Q.W.); (R.L.); (T.L.); (X.Y.); (Z.W.)
- National Clinical Research Center for Skin and Immune Diseases, Beijing 100034, China
- Research Center for Medical Mycology, Peking University, Beijing 100034, China
- Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing 100034, China
| | - Xinyu Yang
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing 100034, China; (Q.W.); (R.L.); (T.L.); (X.Y.); (Z.W.)
- National Clinical Research Center for Skin and Immune Diseases, Beijing 100034, China
- Research Center for Medical Mycology, Peking University, Beijing 100034, China
- Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing 100034, China
| | - Zhe Wan
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing 100034, China; (Q.W.); (R.L.); (T.L.); (X.Y.); (Z.W.)
- National Clinical Research Center for Skin and Immune Diseases, Beijing 100034, China
- Research Center for Medical Mycology, Peking University, Beijing 100034, China
- Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing 100034, China
| | - Wei Liu
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing 100034, China; (Q.W.); (R.L.); (T.L.); (X.Y.); (Z.W.)
- National Clinical Research Center for Skin and Immune Diseases, Beijing 100034, China
- Research Center for Medical Mycology, Peking University, Beijing 100034, China
- Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing 100034, China
- Correspondence: ; Tel.: +86-10-8357-3075
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Vu BG, Stamnes MA, Li Y, Rogers PD, Moye-Rowley WS. The Candida glabrata Upc2A transcription factor is a global regulator of antifungal drug resistance pathways. PLoS Genet 2021; 17:e1009582. [PMID: 34591857 PMCID: PMC8509923 DOI: 10.1371/journal.pgen.1009582] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 10/12/2021] [Accepted: 09/22/2021] [Indexed: 01/15/2023] Open
Abstract
The most commonly used antifungal drugs are the azole compounds, which interfere with biosynthesis of the fungal-specific sterol: ergosterol. The pathogenic yeast Candida glabrata commonly acquires resistance to azole drugs like fluconazole via mutations in a gene encoding a transcription factor called PDR1. These PDR1 mutations lead to overproduction of drug transporter proteins like the ATP-binding cassette transporter Cdr1. In other Candida species, mutant forms of a transcription factor called Upc2 are associated with azole resistance, owing to the important role of this protein in control of expression of genes encoding enzymes involved in the ergosterol biosynthetic pathway. Recently, the C. glabrata Upc2A factor was demonstrated to be required for normal azole resistance, even in the presence of a hyperactive mutant form of PDR1. Using genome-scale approaches, we define the network of genes bound and regulated by Upc2A. By analogy to a previously described hyperactive UPC2 mutation found in Saccharomyces cerevisiae, we generated a similar form of Upc2A in C. glabrata called G898D Upc2A. Analysis of Upc2A genomic binding sites demonstrated that wild-type Upc2A binding to target genes was strongly induced by fluconazole while G898D Upc2A bound similarly, irrespective of drug treatment. Transcriptomic analyses revealed that, in addition to the well-described ERG genes, a large group of genes encoding components of the translational apparatus along with membrane proteins were responsive to Upc2A. These Upc2A-regulated membrane protein-encoding genes are often targets of the Pdr1 transcription factor, demonstrating the high degree of overlap between these two regulatory networks. Finally, we provide evidence that Upc2A impacts the Pdr1-Cdr1 system and also modulates resistance to caspofungin. These studies provide a new perspective of Upc2A as a master regulator of lipid and membrane protein biosynthesis. In the pathogenic yeast Candida glabrata, expression of the genes encoding enzymes in the ergosterol biosynthetic pathway is controlled by the transcription factor Upc2A. C. glabrata has a low intrinsic susceptibility to azole therapy and acquires fluconazole resistance at high frequency. These azole resistant mutants typically contain substitution mutations in a gene encoding the transcription factor Pdr1. Pdr1 does not appear to regulate ergosterol genes and instead induces expression of genes encoding drug transport proteins like CDR1. Here we establish that extensive overlap exists between the regulatory networks defined by Upc2A and Pdr1. Genomic approaches are used to describe the hundreds of genes regulated by Upc2A that far exceed the well-described impact of this factor on genes involved in ergosterol biosynthesis. The overlap between Upc2A and Pdr1 is primarily described by co-regulation of genes encoding membrane transporters like CDR1. We provide evidence that Upc2A impacts the transcriptional control of the FKS1 gene, producing a target of a second major class of antifungal drugs, the echinocandins. Our data are consistent with Upc2A playing a role as a master regulator coordinating the synthesis of membrane structural components, both at the level of lipids and proteins, to produce properly functional biological membranes.
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Affiliation(s)
- Bao Gia Vu
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Mark A. Stamnes
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Yu Li
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - P. David Rogers
- Department of Clinical Pharmacy and Translational Science, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - W. Scott Moye-Rowley
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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Lotfali E, Fattahi A, Sayyahfar S, Ghasemi R, Rabiei MM, Fathi M, Vakili K, Deravi N, Soheili A, Toreyhi H, Shirvani F. A Review on Molecular Mechanisms of Antifungal Resistance in Candida glabrata: Update and Recent Advances. Microb Drug Resist 2021; 27:1371-1388. [PMID: 33956513 DOI: 10.1089/mdr.2020.0235] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Candida glabrata is the second frequent etiologic agent of mucosal and invasive candidiasis. Based on the recent developments in molecular methods, C. glabrata has been introduced as a complex composed of C. glabrata, Candida nivariensis, and Candida bracarensis. The four main classes of antifungal drugs effective against C. glabrata are pyrimidine analogs (flucytosine), azoles, echinocandins, and polyenes. Although the use of antifungal drugs is related to the predictable development of drug resistance, it is not clear why C. glabrata is able to rapidly resist against multiple antifungals in clinics. The enhanced incidence and antifungal resistance of C. glabrata and the high mortality and morbidity need more investigation regarding the resistance mechanisms and virulence associated with C. glabrata; additional progress concerning the drug resistance of C. glabrata has to be further prevented. The present review highlights the mechanism of resistance to antifungal drugs in C. glabrata.
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Affiliation(s)
- Ensieh Lotfali
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Azam Fattahi
- Center for Research and Training in Skin Diseases and Leprosy, Tehran University of Medical Sciences, Tehran, Iran
| | - Shirin Sayyahfar
- Research Center of Pediatric Infectious Diseases, Institute of Immunology and Infectious Diseases, Iran University of Medical Sciences, Tehran, Iran
| | - Reza Ghasemi
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Mahdi Rabiei
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mobina Fathi
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Kimia Vakili
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Niloofar Deravi
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Amirali Soheili
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Toreyhi
- Student Research Committee, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fariba Shirvani
- Pediatric Infections Research Center, Research Institute for Children Health, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Lee Y, Puumala E, Robbins N, Cowen LE. Antifungal Drug Resistance: Molecular Mechanisms in Candida albicans and Beyond. Chem Rev 2021; 121:3390-3411. [PMID: 32441527 PMCID: PMC8519031 DOI: 10.1021/acs.chemrev.0c00199] [Citation(s) in RCA: 311] [Impact Index Per Article: 103.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Fungal infections are a major contributor to infectious disease-related deaths across the globe. Candida species are among the most common causes of invasive mycotic disease, with Candida albicans reigning as the leading cause of invasive candidiasis. Given that fungi are eukaryotes like their human host, the number of unique molecular targets that can be exploited for antifungal development remains limited. Currently, there are only three major classes of drugs approved for the treatment of invasive mycoses, and the efficacy of these agents is compromised by the development of drug resistance in pathogen populations. Notably, the emergence of additional drug-resistant species, such as Candida auris and Candida glabrata, further threatens the limited armamentarium of antifungals available to treat these serious infections. Here, we describe our current arsenal of antifungals and elaborate on the resistance mechanisms Candida species possess that render them recalcitrant to therapeutic intervention. Finally, we highlight some of the most promising therapeutic strategies that may help combat antifungal resistance, including combination therapy, targeting fungal-virulence traits, and modulating host immunity. Overall, a thorough understanding of the mechanistic principles governing antifungal drug resistance is fundamental for the development of novel therapeutics to combat current and emerging fungal threats.
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Affiliation(s)
- Yunjin Lee
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, Ontario M5G 1M1, Canada
| | - Emily Puumala
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, Ontario M5G 1M1, Canada
| | - Nicole Robbins
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, Ontario M5G 1M1, Canada
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, Ontario M5G 1M1, Canada
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Identification of Essential Genes and Fluconazole Susceptibility Genes in Candida glabrata by Profiling Hermes Transposon Insertions. G3-GENES GENOMES GENETICS 2020; 10:3859-3870. [PMID: 32819971 PMCID: PMC7534453 DOI: 10.1534/g3.120.401595] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Within the budding yeasts, the opportunistic pathogen Candida glabrata and other members of the Nakaseomyces clade have developed virulence traits independently from C. albicans and C. auris. To begin exploring the genetic basis of C. glabrata virulence and its innate resistance to antifungals, we launched the Hermes transposon from a plasmid and sequenced more than 500,000 different semi-random insertions throughout the genome. With machine learning, we identified 1278 protein-encoding genes (25% of total) that could not tolerate transposon insertions and are likely essential for C. glabrata fitness in vitro. Interestingly, genes involved in mRNA splicing were less likely to be essential in C. glabrata than their orthologs in S. cerevisiae, whereas the opposite is true for genes involved in kinetochore function and chromosome segregation. When a pool of insertion mutants was challenged with the first-line antifungal fluconazole, insertions in several known resistance genes (e.g., PDR1, CDR1, PDR16, PDR17, UPC2A, DAP1, STV1) and 15 additional genes (including KGD1, KGD2, YHR045W) became hypersensitive to fluconazole. Insertions in 200 other genes conferred significant resistance to fluconazole, two-thirds of which function in mitochondria and likely down-regulate Pdr1 expression or function. Knockout mutants of KGD2 and IDH2, which consume and generate alpha-ketoglutarate in mitochondria, exhibited increased and decreased resistance to fluconazole through a process that depended on Pdr1. These findings establish the utility of transposon insertion profiling in forward genetic investigations of this important pathogen of humans.
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Affiliation(s)
- W. Scott Moye-Rowley
- Department of Molecular Physiology and Biophysics, Carver College of Medicine University of Iowa, Iowa City, Iowa, United States of America
- * E-mail:
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Arastehfar A, Lass-Flörl C, Garcia-Rubio R, Daneshnia F, Ilkit M, Boekhout T, Gabaldon T, Perlin DS. The Quiet and Underappreciated Rise of Drug-Resistant Invasive Fungal Pathogens. J Fungi (Basel) 2020; 6:E138. [PMID: 32824785 PMCID: PMC7557958 DOI: 10.3390/jof6030138] [Citation(s) in RCA: 63] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 07/22/2020] [Accepted: 08/11/2020] [Indexed: 12/13/2022] Open
Abstract
Human fungal pathogens are attributable to a significant economic burden and mortality worldwide. Antifungal treatments, although limited in number, play a pivotal role in decreasing mortality and morbidities posed by invasive fungal infections (IFIs). However, the recent emergence of multidrug-resistant Candida auris and Candida glabrata and acquiring invasive infections due to azole-resistant C. parapsilosis, C. tropicalis, and Aspergillus spp. in azole-naïve patients pose a serious health threat considering the limited number of systemic antifungals available to treat IFIs. Although advancing for major fungal pathogens, the understanding of fungal attributes contributing to antifungal resistance is just emerging for several clinically important MDR fungal pathogens. Further complicating the matter are the distinct differences in antifungal resistance mechanisms among various fungal species in which one or more mechanisms may contribute to the resistance phenotype. In this review, we attempt to summarize the burden of antifungal resistance for selected non-albicansCandida and clinically important Aspergillus species together with their phylogenetic placement on the tree of life. Moreover, we highlight the different molecular mechanisms between antifungal tolerance and resistance, and comprehensively discuss the molecular mechanisms of antifungal resistance in a species level.
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Affiliation(s)
- Amir Arastehfar
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA;
| | - Cornelia Lass-Flörl
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, 6020 Innsbruck, Austria;
| | - Rocio Garcia-Rubio
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA;
| | - Farnaz Daneshnia
- Westerdijk Fungal Biodiversity Institute, 3584 CT Utrecht, The Netherlands; (F.D.); (T.B.)
| | - Macit Ilkit
- Division of Mycology, University of Çukurova, 01330 Adana, Turkey;
| | - Teun Boekhout
- Westerdijk Fungal Biodiversity Institute, 3584 CT Utrecht, The Netherlands; (F.D.); (T.B.)
- Institute of Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, 1012 WX Amsterdam, The Netherlands
| | - Toni Gabaldon
- Life Sciences Programme, Barcelona, Supercomputing Center (BSC-CNS), Jordi Girona, 08034 Barcelona, Spain;
- Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB), 08024 Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain
| | - David S. Perlin
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA;
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20
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Arastehfar A, Daneshnia F, Salehi M, Yaşar M, Hoşbul T, Ilkit M, Pan W, Hagen F, Arslan N, Türk-Dağı H, Hilmioğlu-Polat S, Perlin DS, Lass-Flörl C. Low level of antifungal resistance of Candida glabrata blood isolates in Turkey: Fluconazole minimum inhibitory concentration and FKS mutations can predict therapeutic failure. Mycoses 2020; 63:911-920. [PMID: 32413170 PMCID: PMC7497236 DOI: 10.1111/myc.13104] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 04/25/2020] [Accepted: 05/02/2020] [Indexed: 12/26/2022]
Abstract
Background Candida glabrata is the third leading cause of candidaemia in Turkey; however, the data regarding antifungal resistance mechanisms and genotypic diversity in association with their clinical implication are limited. Objectives To assess genotypic diversity, antifungal susceptibility and mechanisms of drug resistance of Cglabrata blood isolates and their association with patients' outcome in a retrospective multicentre study. Patients/Methods Isolates from 107 patients were identified by ITS sequencing and analysed by multilocus microsatellite typing, antifungal susceptibility testing, and sequencing of PDR1 and FKS1/2 hotspots (HSs). Results Candida glabrata prevalence in Ege University Hospital was twofold higher in 2014‐2019 than in 2005‐2014. Six of the analysed isolates had fluconazole MICs ≥ 32 µg/mL; of them, five harboured unique PDR1 mutations. Although echinocandin resistance was not detected, three isolates had mutations in HS1‐Fks1 (S629T, n = 1) and HS1‐Fks2 (S663P, n = 2); one of the latter was also fluconazole‐resistant. All patients infected with isolates carrying HS‐FKS mutations and/or demonstrating fluconazole MIC ≥ 32 µg/mL (except one without clinical data) showed therapeutic failure (TF) with echinocandin and fluconazole; seven such isolates were collected in Ege (n = 4) and Gulhane (n = 3) hospitals and six detected recently. Among 34 identified genotypes, none were associated with mortality or enriched for fluconazole‐resistant isolates. Conclusion Antifungal susceptibility testing should be supplemented with HS‐FKS sequencing to predict TF for echinocandins, whereas fluconazole MIC ≥ 32 µg/mL may predict TF. Recent emergence of C glabrata isolates associated with antifungal TF warrants future comprehensive prospective studies in Turkey.
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Affiliation(s)
- Amir Arastehfar
- Shanghai Key Laboratory Molecular Medical Mycology, Shanghai, China.,Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - Farnaz Daneshnia
- Shanghai Key Laboratory Molecular Medical Mycology, Shanghai, China
| | - Mohammadreza Salehi
- Department of Infectious Diseases and Tropical Medicine, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Melike Yaşar
- Department of Medical Microbiology, Faculty of Medicine, Ege University, Izmir, Turkey
| | - Tuğrul Hoşbul
- Department of Medical Microbiology, Gulhane Training and Research Hospital, University of Health Sciences, Ankara, Turkey
| | - Macit Ilkit
- Division of Mycology, Faculty of Medicine, Çukurova University, Adana, Turkey
| | - Weihua Pan
- Shanghai Key Laboratory Molecular Medical Mycology, Shanghai, China
| | - Ferry Hagen
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands.,University Medical Center Utrecht, Utrecht, The Netherlands.,People's Hospital, Jining, China
| | - Nazlı Arslan
- Department of Medical Microbiology, Dokuz Eylül University Faculty of Medicine, Izmir, Turkey
| | - Hatice Türk-Dağı
- Department of Microbiology, Faculty of Medicine, Selcuk University, Konya, Turkey
| | | | - David S Perlin
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, USA
| | - Cornelia Lass-Flörl
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
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21
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Salazar SB, Simões RS, Pedro NA, Pinheiro MJ, Carvalho MFNN, Mira NP. An Overview on Conventional and Non-Conventional Therapeutic Approaches for the Treatment of Candidiasis and Underlying Resistance Mechanisms in Clinical Strains. J Fungi (Basel) 2020; 6:jof6010023. [PMID: 32050673 PMCID: PMC7151124 DOI: 10.3390/jof6010023] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/06/2020] [Accepted: 02/07/2020] [Indexed: 02/06/2023] Open
Abstract
Fungal infections and, in particular, those caused by species of the Candida genus, are growing at an alarming rate and have high associated rates of mortality and morbidity. These infections, generally referred as candidiasis, range from common superficial rushes caused by an overgrowth of the yeasts in mucosal surfaces to life-threatening disseminated mycoses. The success of currently used antifungal drugs to treat candidiasis is being endangered by the continuous emergence of resistant strains, specially among non-albicans Candida species. In this review article, the mechanisms of action of currently used antifungals, with emphasis on the mechanisms of resistance reported in clinical isolates, are reviewed. Novel approaches being taken to successfully inhibit growth of pathogenic Candida species, in particular those based on the exploration of natural or synthetic chemicals or on the activity of live probiotics, are also reviewed. It is expected that these novel approaches, either used alone or in combination with traditional antifungals, may contribute to foster the identification of novel anti-Candida therapies.
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Affiliation(s)
- Sara B. Salazar
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (S.B.S.); (R.S.S.); (N.A.P.); (M.J.P.)
| | - Rita S. Simões
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (S.B.S.); (R.S.S.); (N.A.P.); (M.J.P.)
| | - Nuno A. Pedro
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (S.B.S.); (R.S.S.); (N.A.P.); (M.J.P.)
| | - Maria Joana Pinheiro
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (S.B.S.); (R.S.S.); (N.A.P.); (M.J.P.)
| | - Maria Fernanda N. N. Carvalho
- Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal;
| | - Nuno P. Mira
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (S.B.S.); (R.S.S.); (N.A.P.); (M.J.P.)
- Correspondence:
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Impact of the Major Candida glabrata Triazole Resistance Determinants on the Activity of the Novel Investigational Tetrazoles VT-1598 and VT-1161. Antimicrob Agents Chemother 2019; 63:AAC.01304-19. [PMID: 31383660 DOI: 10.1128/aac.01304-19] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 07/26/2019] [Indexed: 02/06/2023] Open
Abstract
VT-1161 and VT-1598 are promising investigational tetrazole antifungals that have shown in vitro and in vivo activity against Candida and other fungi. Candida glabrata is a problematic opportunistic pathogen that is associated with high mortality in invasive infection, as well as both intrinsic and rapidly acquired antifungal resistance. The MICs of VT-1161 and VT-1598 were determined by CLSI methodology to evaluate their in vitro activities against clinical C. glabrata isolates and strains containing individual deletions of the zinc cluster transcription factor genes PDR1 and UPC2A as well as the efflux transporter genes CDR1, PDH1, and SNQ2 Overall, both tetrazoles demonstrated relative activities comparable to those of the tested triazole antifungals against clinical C. glabrata isolates (MIC range, 0.25 to 2 mg/liter and 0.5 to 2 μg/ml for VT-1161 and VT-1598, respectively). Deletion of the PDR1 gene in fluconazole-resistant matched clinical isolate SM3 abolished the decreased susceptibility phenotype completely for both VT-1161 and VT-1598, similarly to the triazoles. UPC2A deletion also increased susceptibility to both triazoles and tetrazoles but to a lesser extent than PDR1 deletion. Of the three major transporter genes regulated by Pdr1, CDR1 deletion resulted in the largest MIC reductions for all agents tested, while PDH1 and SNQ2 deletion individually impacted MICs very little. Overall, both VT-1161 and VT-1598 have comparable activities to those of the available triazoles, and decreased susceptibility to these tetrazoles in C. glabrata is driven by many of the same known resistance mechanisms.
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Shivarathri R, Tscherner M, Zwolanek F, Singh NK, Chauhan N, Kuchler K. The Fungal Histone Acetyl Transferase Gcn5 Controls Virulence of the Human Pathogen Candida albicans through Multiple Pathways. Sci Rep 2019; 9:9445. [PMID: 31263212 PMCID: PMC6603162 DOI: 10.1038/s41598-019-45817-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 06/14/2019] [Indexed: 12/28/2022] Open
Abstract
Fungal virulence is regulated by a tight interplay of transcriptional control and chromatin remodelling. Despite compelling evidence that lysine acetylation modulates virulence of pathogenic fungi such as Candida albicans, the underlying mechanisms have remained largely unexplored. We report here that Gcn5, a paradigm lysyl-acetyl transferase (KAT) modifying both histone and non-histone targets, controls fungal morphogenesis - a key virulence factor of C. albicans. Our data show that genetic removal of GCN5 abrogates fungal virulence in mice, suggesting strongly diminished fungal fitness in vivo. This may at least in part arise from increased susceptibility to killing by macrophages, as well as by other phagocytes such as neutrophils or monocytes. Loss of GCN5 also causes hypersensitivity to the fungicidal drug caspofungin. Caspofungin hypersusceptibility requires the master regulator Efg1, working in concert with Gcn5. Moreover, Gcn5 regulates multiple independent pathways, including adhesion, cell wall-mediated MAP kinase signaling, hypersensitivity to host-derived oxidative stress, and regulation of the Fks1 glucan synthase, all of which play critical roles in virulence and antifungal susceptibility. Hence, Gcn5 regulates fungal virulence through multiple mechanisms, suggesting that specific inhibition of Gcn5 could offer new therapeutic strategies to combat invasive fungal infections.
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Affiliation(s)
- Raju Shivarathri
- Medical University of Vienna, Max Perutz Labs Vienna, Campus Vienna Biocenter, A-1030, Vienna, Austria
| | - Michael Tscherner
- Medical University of Vienna, Max Perutz Labs Vienna, Campus Vienna Biocenter, A-1030, Vienna, Austria
| | - Florian Zwolanek
- Medical University of Vienna, Max Perutz Labs Vienna, Campus Vienna Biocenter, A-1030, Vienna, Austria
| | | | - Neeraj Chauhan
- Public Health Research Institute, New Jersey Medical School, Rutgers The State University of New Jersey, Newark, NJ, 07103, USA.
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers The State University of New Jersey, Newark, NJ, 07103, USA.
| | - Karl Kuchler
- Medical University of Vienna, Max Perutz Labs Vienna, Campus Vienna Biocenter, A-1030, Vienna, Austria.
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Evidence that Ergosterol Biosynthesis Modulates Activity of the Pdr1 Transcription Factor in Candida glabrata. mBio 2019; 10:mBio.00934-19. [PMID: 31186322 PMCID: PMC6561024 DOI: 10.1128/mbio.00934-19] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
A likely contributor to the increased incidence of non-albicans candidemias involving Candida glabrata is the ease with which this yeast acquires azole resistance, in large part due to induction of the ATP-binding cassette transporter-encoding gene CDR1. Azole drugs lead to induction of Pdr1 transactivation, with a central model being that this factor binds these drugs directly. Here we provide evidence that Pdr1 is activated without azole drugs by the use of genetic means to inhibit expression of azole drug target-encoding gene ERG11. These acute reductions in Erg11 levels lead to elevated Pdr1 activity even though no drug is present. A key transcriptional regulator of the ERG pathway, Upc2A, is shown to directly bind to the PDR1 and CDR1 promoters. We interpret these data as support for the view that Pdr1 function is responsive to ergosterol biosynthesis and suggest that this connection reveals the normal physiological circuitry in which Pdr1 participates. A crucial limitation in antifungal chemotherapy is the limited number of antifungal drugs currently available. Azole drugs represent the most commonly used chemotherapeutic, and loss of efficacy of these drugs is a major risk factor in successful treatment of a variety of fungal diseases. Candida glabrata is a pathogenic yeast that is increasingly found associated with bloodstream infections, a finding likely contributed to by its proclivity to develop azole drug resistance. C. glabrata often acquires azole resistance via gain-of-function (GOF) mutations in the transcription factor Pdr1. These GOF forms of Pdr1 drive elevated expression of target genes, including the ATP-binding cassette transporter-encoding CDR1 locus. GOF alleles of PDR1 have been extensively studied, but little is known of how Pdr1 is normally regulated. Here we test the idea that reduction of ergosterol biosynthesis (as occurs in the presence of azole drugs) might trigger activation of Pdr1 function. Using two different means of genetically inhibiting ergosterol biosynthesis, we demonstrated that Pdr1 activity and target gene expression are elevated in the absence of azole drug. Blocks at different points in the ergosterol pathway lead to Pdr1 activation as well as to induction of other genes in this pathway. Delivery of the signal from the ergosterol pathway to Pdr1 involves the transcription factor Upc2A, an ERG gene regulator. We show that Upc2A binds directly to the PDR1 and CDR1 promoters. Our studies argue for a physiological link between ergosterol biosynthesis and Pdr1-dependent gene regulation that is not restricted to efflux of azole drugs.
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Sharma J, Rosiana S, Razzaq I, Shapiro RS. Linking Cellular Morphogenesis with Antifungal Treatment and Susceptibility in Candida Pathogens. J Fungi (Basel) 2019; 5:E17. [PMID: 30795580 PMCID: PMC6463059 DOI: 10.3390/jof5010017] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Revised: 02/11/2019] [Accepted: 02/13/2019] [Indexed: 02/07/2023] Open
Abstract
Fungal infections are a growing public health concern, and an increasingly important cause of human mortality, with Candida species being amongst the most frequently encountered of these opportunistic fungal pathogens. Several Candida species are polymorphic, and able to transition between distinct morphological states, including yeast, hyphal, and pseudohyphal forms. While not all Candida pathogens are polymorphic, the ability to undergo morphogenesis is linked with the virulence of many of these pathogens. There are also many connections between Candida morphogenesis and antifungal drug treatment and susceptibility. Here, we review how Candida morphogenesis-a key virulence trait-is linked with antifungal drugs and antifungal drug resistance. We highlight how antifungal therapeutics are able to modulate morphogenesis in both sensitive and drug-resistant Candida strains, the shared signaling pathways that mediate both morphogenesis and the cellular response to antifungal drugs and drug resistance, and the connection between Candida morphology, drug resistance, and biofilm growth. We further review the development of anti-virulence drugs, and targeting Candida morphogenesis as a novel therapeutic strategy to target fungal pathogens. Together, this review highlights important connections between fungal morphogenesis, virulence, and susceptibility to antifungals.
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Affiliation(s)
- Jehoshua Sharma
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Sierra Rosiana
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Iqra Razzaq
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
| | - Rebecca S Shapiro
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
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Tantivitayakul P, Lapirattanakul J, Kaypetch R, Muadcheingka T. Missense mutation in CgPDR1 regulator associated with azole-resistant Candida glabrata recovered from Thai oral candidiasis patients. J Glob Antimicrob Resist 2019; 17:221-226. [PMID: 30658200 DOI: 10.1016/j.jgar.2019.01.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/19/2018] [Accepted: 01/09/2019] [Indexed: 01/04/2023] Open
Abstract
OBJECTIVES Non-albicans Candida (NAC) species are increasingly identified as pathogens causing oral candidiasis. Incidence rates for azole resistance among NAC species have been continuously reported. This study aimed to evaluate the azole susceptibility profiles and to characterise the azole resistance mechanisms of oral clinical NAC isolates. METHODS In vitro susceptibility patterns of 85 NAC species isolates were determined by the broth microdilution method. Azole resistance-related genes (ERG3, ERG11 and PDR1) of Candida glabrata isolates were sequenced to determine the presence of nucleotide substitutions. Expression levels of various resistance-related genes were also evaluated by RT-qPCR in azole-susceptible, susceptible dose-dependent (SDD) and resistant Candida isolates. RESULTS Two C. glabrata isolates (2.4% of all NAC isolates) were resistant to all three azoles tested (fluconazole, itraconazole and ketoconazole). All clinical isolates of Candida tropicalis and Candida kefyr were susceptible to azoles. Silent mutations were found in the CgERG11 and CgERG3 genes of clinical C. glabrata isolates. Interestingly, two missense mutations in CgPDR1 (N768D and E818K) were identified only in resistant C. glabrata isolates. The presence of a CgPDR1 missense mutation in resistant isolates is associated with overexpression of its own product as well as multidrug transporters including ABC and MFS transporters. CONCLUSION A gain-of-function (GOF) mutation in CgPDR1 is associated with upregulation of various drug transporters, which appears to serve as a primary mechanism for azole resistance in the detected C. glabrata isolates. Therefore, analysis of GOF mutations in the PDR1 regulator provides a better understanding of the development of antifungal resistance.
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Affiliation(s)
- Pornpen Tantivitayakul
- Department of Oral Microbiology, Faculty of Dentistry, Mahidol University, 6 Yothi Street, Rajthevi, Bangkok 10400, Thailand.
| | - Jinthana Lapirattanakul
- Department of Oral Microbiology, Faculty of Dentistry, Mahidol University, 6 Yothi Street, Rajthevi, Bangkok 10400, Thailand
| | - Rattiporn Kaypetch
- Research Office, Faculty of Dentistry, Mahidol University, Bangkok, Thailand
| | - Thaniya Muadcheingka
- Department of Oral Microbiology, Faculty of Dentistry, Mahidol University, 6 Yothi Street, Rajthevi, Bangkok 10400, Thailand
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Zhang J, Li L, Lv Q, Yan L, Wang Y, Jiang Y. The Fungal CYP51s: Their Functions, Structures, Related Drug Resistance, and Inhibitors. Front Microbiol 2019; 10:691. [PMID: 31068906 PMCID: PMC6491756 DOI: 10.3389/fmicb.2019.00691] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Accepted: 03/19/2019] [Indexed: 12/18/2022] Open
Abstract
CYP51 (Erg11) belongs to the cytochrome P450 monooxygenase (CYP) superfamily and mediates a crucial step of the synthesis of ergosterol, which is a fungal-specific sterol. It is also the target of azole drugs in clinical practice. In recent years, researches on fungal CYP51 have stepped into a new stage attributing to the discovery of crystal structures of the homologs in Candida albicans, Cryptococcus neoformans and Aspergillus fumigatus. This review summarizes the functions, structures of fungal CYP51 proteins, and the inhibitors targeting these homologs. In particular, several drug-resistant mechanisms associated with the fungal CYP51s are introduced. The sequences and crystal structures of CYP51 proteins in different fungal species are also compared. These will provide new insights for the advancement of research on antifungal agents.
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Affiliation(s)
- Jingxiang Zhang
- Center for New Drug Research, School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Liping Li
- Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
- Department of Pharmacology, Tongji University School of Medicine, Shanghai, China
| | - Quanzhen Lv
- Center for New Drug Research, School of Pharmacy, Second Military Medical University, Shanghai, China
| | - Lan Yan
- Center for New Drug Research, School of Pharmacy, Second Military Medical University, Shanghai, China
- *Correspondence: Lan Yan, Yan Wang, Yuanying Jiang,
| | - Yan Wang
- Center for New Drug Research, School of Pharmacy, Second Military Medical University, Shanghai, China
- *Correspondence: Lan Yan, Yan Wang, Yuanying Jiang,
| | - Yuanying Jiang
- Center for New Drug Research, School of Pharmacy, Second Military Medical University, Shanghai, China
- Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
- Department of Pharmacology, Tongji University School of Medicine, Shanghai, China
- *Correspondence: Lan Yan, Yan Wang, Yuanying Jiang,
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28
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Pais P, Galocha M, Teixeira MC. Genome-Wide Response to Drugs and Stress in the Pathogenic Yeast Candida glabrata. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2019; 58:155-193. [PMID: 30911893 DOI: 10.1007/978-3-030-13035-0_7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Candida glabrata is the second most common cause of candidemia worldwide and its prevalence has continuously increased over the last decades. C. glabrata infections are especially worrisome in immunocompromised patients, resulting in serious systemic infections, associated to high mortality rates. Intrinsic resistance to azole antifungals, widely used drugs in the clinical setting, and the ability to efficiently colonize the human host and medical devices, withstanding stress imposed by the immune system, are thought to underlie the emergence of C. glabrata. There is a clear clinical need to understand drug and stress resistance in C. glabrata. The increasing prevalence of multidrug resistant isolates needs to be addressed in order to overcome the decrease of viable therapeutic strategies and find new therapeutic targets. Likewise, the understanding of the mechanisms underlying its impressive ability thrive under oxidative, nitrosative, acidic and metabolic stresses, is crucial to design drugs that target these pathogenesis features. The study of the underlying mechanisms that translate C. glabrata plasticity and its competence to evade the immune system, as well as survive host stresses to establish infection, will benefit from extensive scrutiny. This chapter provides a review on the contribution of genome-wide studies to uncover clinically relevant drug resistance and stress response mechanisms in the human pathogenic yeast C. glabrata.
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Affiliation(s)
- Pedro Pais
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.,Biological Sciences Research Group, Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Mónica Galocha
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.,Biological Sciences Research Group, Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Miguel Cacho Teixeira
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal. .,Biological Sciences Research Group, Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.
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Azole Resistance Reduces Susceptibility to the Tetrazole Antifungal VT-1161. Antimicrob Agents Chemother 2018; 63:AAC.02114-18. [PMID: 30397057 DOI: 10.1128/aac.02114-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 10/29/2018] [Indexed: 01/07/2023] Open
Abstract
Tetrazole antifungals designed to target fungal lanosterol 14α-demethylase (LDM) appear to be effective against a range of fungal pathogens. In addition, a crystal structure of the catalytic domain of Candida albicans LDM in complex with the tetrazole VT-1161 has been obtained. We have addressed concern about artifacts that might arise from crystallizing VT-1161 with truncated recombinant CYP51s and measured the impact on VT-1161 susceptibility of genotypes known to confer azole resistance. A yeast system was used to overexpress recombinant full-length Saccharomyces cerevisiae LDM with a C-terminal hexahistidine tag (ScLDM6×His) for phenotypic analysis and crystallographic studies with VT-1161 or with the widely used triazole drug posaconazole (PCZ). We determined the effect of characterized mutations in LDM on VT-1161 activity and identified drug efflux pumps from fungi, including key fungal pathogens, that efflux VT-1161. The relevance of these yeast-based observations on drug efflux was verified using clinical isolates of C. albicans and Candida glabrata VT-1161 binding elicits a significant conformational difference between the full-length and truncated enzymes not found when posaconazole is bound. Susceptibility to VT-1161 is reduced by ATP-binding cassette (ABC) and major facilitator superfamily (MFS) drug efflux pumps, the overexpression of LDM, and mutations within the drug binding pocket of LDM that affect interaction with the tertiary alcohol of the drug.
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30
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Wang SQ, Wang T, Liu JF, Deng L, Wang F. Overexpression of Ecm22 improves ergosterol biosynthesis in Saccharomyces cerevisiae. Lett Appl Microbiol 2018; 67:484-490. [PMID: 30098030 DOI: 10.1111/lam.13061] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 07/17/2018] [Accepted: 07/28/2018] [Indexed: 12/01/2022]
Abstract
Ergosterol biosynthesis in Saccharomyces cerevisiae is complex and the underlying mechanism of regulation remains unclear. To clarify the influence of transcriptional regulation on the ergosterol content, transcription factor Ecm22 was overexpressed in S. cerevisiae. Results showed that the overexpression of ECM22 led to an increased invasive growth. Fluconazole susceptibility testing indicated that strains overexpressing ECM22 could grow at 20 μg(fluconazole) ml-1 . By contrast, the control failed to grow at 16 μg(fluconazole) ml-1 . Among truncated ECM22 fragments, only the 1440-bp DNA fragment exerted almost the same impact on ergosterol content as that of the full-length gene. In a 5-l bioreactor, the highest ergosterol yield of the recombinant reached 32∙7 mg g(dry cell weight) -1 , which was increased by about 20% compared with that of the control. In this work, a novel approach for enhancing the ergosterol production by overexpressing a transcription factor in S. cerevisiae was developed.
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Affiliation(s)
- S-Q Wang
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - T Wang
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - J-F Liu
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - L Deng
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
| | - F Wang
- Beijing Key Laboratory of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, China
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Li QQ, Tsai HF, Mandal A, Walker BA, Noble JA, Fukuda Y, Bennett JE. Sterol uptake and sterol biosynthesis act coordinately to mediate antifungal resistance in Candida glabrata under azole and hypoxic stress. Mol Med Rep 2018. [PMID: 29532896 PMCID: PMC5928633 DOI: 10.3892/mmr.2018.8716] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Pathogenic fungi, including Candida glabrata, develop strategies to grow and survive both in vitro and in vivo under azole stress. However, the mechanisms by which yeast cells counteract the inhibitory effects of azoles are not completely understood. In the current study, it was demonstrated that the expression of the ergosterol biosynthetic genes ERG2, ERG3, ERG4, ERG10, and ERG11 was significantly upregulated in C. glabrata following fluconazole treatment. Inhibiting ergosterol biosynthesis using fluconazole also increased the expression of the sterol influx transporter AUS1 and the sterol metabolism regulators SUT1 and UPC2 in fungal cells. The microarray study quantified 35 genes with elevated mRNA levels, including AUS1, TIR3, UPC2, and 8 ERG genes, in a C. glabrata mutant strain lacking ERG1, indicating that sterol importing activity is increased to compensate for defective sterol biosynthesis in cells. Bioinformatic analyses further revealed that those differentially expressed genes were involved in multiple cellular processes and biological functions, such as sterol biosynthesis, lipid localization, and sterol transport. Finally, to assess whether sterol uptake affects yeast susceptibility to azoles, we generated a C. glabrata aus1∆ mutant strain. It was shown that loss of Aus1p in C. glabrata sensitized the pathogen to azoles and enhanced the efficacy of drug exposure under low oxygen tension. In contrast, the presence of exogenous cholesterol or ergosterol in medium rendered the C. glabrata AUS1 wild-type strain highly resistant to fluconazole and voriconazole, suggesting that the sterol importing mechanism is augmented when ergosterol biosynthesis is suppressed in the cell, thus allowing C. glabrata to survive under azole pressure. On the basis of these results, it was concluded that sterol uptake and sterol biosynthesis may act coordinately and collaboratively to sustain growth and to mediate antifungal resistance in C. glabrata through dynamic gene expression in response to azole stress and environmental challenges.
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Affiliation(s)
- Qingdi Quentin Li
- Clinical Mycology Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Huei-Fung Tsai
- Clinical Mycology Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ajeet Mandal
- Molecular and Cellular Biochemistry Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
| | - Bryan A Walker
- Clinical Mycology Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jason A Noble
- Clinical Mycology Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yuichi Fukuda
- Clinical Mycology Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - John E Bennett
- Clinical Mycology Section, Laboratory of Clinical Infectious Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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Joshua IM, Höfken T. From Lipid Homeostasis to Differentiation: Old and New Functions of the Zinc Cluster Proteins Ecm22, Upc2, Sut1 and Sut2. Int J Mol Sci 2017; 18:ijms18040772. [PMID: 28379181 PMCID: PMC5412356 DOI: 10.3390/ijms18040772] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 03/27/2017] [Accepted: 03/31/2017] [Indexed: 12/27/2022] Open
Abstract
Zinc cluster proteins are a large family of transcriptional regulators with a wide range of biological functions. The zinc cluster proteins Ecm22, Upc2, Sut1 and Sut2 have initially been identified as regulators of sterol import in the budding yeast Saccharomyces cerevisiae. These proteins also control adaptations to anaerobic growth, sterol biosynthesis as well as filamentation and mating. Orthologs of these zinc cluster proteins have been identified in several species of Candida. Upc2 plays a critical role in antifungal resistance in these important human fungal pathogens. Upc2 is therefore an interesting potential target for novel antifungals. In this review we discuss the functions, mode of actions and regulation of Ecm22, Upc2, Sut1 and Sut2 in budding yeast and Candida.
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Affiliation(s)
| | - Thomas Höfken
- Division of Biosciences, Brunel University London, Uxbridge UB8 3PH, UK.
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33
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The Celecoxib Derivative AR-12 Has Broad-Spectrum Antifungal Activity In Vitro and Improves the Activity of Fluconazole in a Murine Model of Cryptococcosis. Antimicrob Agents Chemother 2016; 60:7115-7127. [PMID: 27645246 DOI: 10.1128/aac.01061-16] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Accepted: 09/04/2016] [Indexed: 12/24/2022] Open
Abstract
Only one new class of antifungal drugs has been introduced into clinical practice in the last 30 years, and thus the identification of small molecules with novel mechanisms of action is an important goal of current anti-infective research. Here, we describe the characterization of the spectrum of in vitro activity and in vivo activity of AR-12, a celecoxib derivative which has been tested in a phase I clinical trial as an anticancer agent. AR-12 inhibits fungal acetyl coenzyme A (acetyl-CoA) synthetase in vitro and is fungicidal at concentrations similar to those achieved in human plasma. AR-12 has a broad spectrum of activity, including activity against yeasts (e.g., Candida albicans, non-albicans Candida spp., Cryptococcus neoformans), molds (e.g., Fusarium, Mucor), and dimorphic fungi (Blastomyces, Histoplasma, and Coccidioides) with MICs of 2 to 4 μg/ml. AR-12 is also active against azole- and echinocandin-resistant Candida isolates, and subinhibitory AR-12 concentrations increase the susceptibility of fluconazole- and echinocandin-resistant Candida isolates. Finally, AR-12 also increases the activity of fluconazole in a murine model of cryptococcosis. Taken together, these data indicate that AR-12 represents a promising class of small molecules with broad-spectrum antifungal activity.
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35
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Dhieb C, Normand AC, Al-Yasiri M, Chaker E, El Euch D, Vranckx K, Hendrickx M, Sadfi N, Piarroux R, Ranque S. MALDI-TOF typing highlights geographical and fluconazole resistance clusters in Candida glabrata. Med Mycol 2015; 53:462-9. [PMID: 25841053 DOI: 10.1093/mmy/myv013] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 02/09/2015] [Indexed: 12/12/2022] Open
Abstract
Utilizing matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectra for Candida glabrata typing would be a cost-effective and easy-to-use alternative to classical DNA-based typing methods. This study aimed to use MALDI-TOF for the typing of C. glabrata clinical isolates from various geographical origins and test its capacity to differentiate between fluconazole-sensitive and -resistant strains.Both microsatellite length polymorphism (MLP) and MALDI-TOF mass spectra of 58 C. glabrata isolates originating from Marseilles (France) and Tunis (Tunisia) as well as collection strains from diverse geographic origins were analyzed. The same analysis was conducted on a subset of C. glabrata isolates that were either susceptible (MIC ≤ 8 mg/l) or resistant (MIC ≥ 64 mg/l) to fluconazole.According to the seminal results, both MALDI-TOF and MLP classifications could highlight C. glabrata population structures associated with either geographical dispersal barriers (p < 10(-5)) or the selection of antifungal drug resistance traits (<10(-5)).In conclusion, MALDI-TOF geographical clustering was congruent with MPL genotyping and highlighted a significant population genetic structure according to fluconazole susceptibility in C. glabrata. Furthermore, although MALDI-TOF and MLP resulted in distinct classifications, MALDI-TOF also classified the isolates with respect to their fluconazole susceptibility profile. Further prospective studies are required to evaluate the capacity of MALDI-TOF typing to investigate C. glabrata infection outbreaks and predict the antifungal susceptibility profile of clinical laboratory isolates.
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Affiliation(s)
- C Dhieb
- Laboratoire des Microorganismes et Biomolécules Actives, Faculté des Sciences de Tunis, 2092 Tunis, Tunisia
| | - A C Normand
- Parasitolgy-Mycology, APHM, CHU Timone, Marseille, France
| | - M Al-Yasiri
- Aix Marseille Université, IP-TPT UMR MD3, 13005, Marseille, France
| | - E Chaker
- Laboratoire de Parasitologie, Hôpital La Rabta, Tunis, Tunisia
| | - D El Euch
- Service de Dermatologie et de Vénéréologie, Hôpital La Rabta, Tunis, Tunisia
| | - K Vranckx
- Applied Maths NV, 9830, Sint-Martens-Latem, Belgium
| | - M Hendrickx
- BCCM/IHEM: Scientific Institute of Public Health, Mycology and Aerobiology Section, Brussels, Belgium
| | - N Sadfi
- Laboratoire des Microorganismes et Biomolécules Actives, Faculté des Sciences de Tunis, 2092 Tunis, Tunisia
| | - R Piarroux
- Parasitolgy-Mycology, APHM, CHU Timone, Marseille, France Aix Marseille Université, IP-TPT UMR MD3, 13005, Marseille, France
| | - S Ranque
- Parasitolgy-Mycology, APHM, CHU Timone, Marseille, France Aix Marseille Université, IP-TPT UMR MD3, 13005, Marseille, France
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36
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Yang H, Tong J, Lee CW, Ha S, Eom SH, Im YJ. Structural mechanism of ergosterol regulation by fungal sterol transcription factor Upc2. Nat Commun 2015; 6:6129. [PMID: 25655993 DOI: 10.1038/ncomms7129] [Citation(s) in RCA: 114] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 12/15/2014] [Indexed: 11/09/2022] Open
Abstract
Transcriptional regulation of ergosterol biosynthesis in fungi is crucial for sterol homeostasis and for resistance to azole drugs. In Saccharomyces cerevisiae, the Upc2 transcription factor activates the expression of related genes in response to sterol depletion by poorly understood mechanisms. We have determined the structure of the C-terminal domain (CTD) of Upc2, which displays a novel α-helical fold with a deep hydrophobic pocket. We discovered that the conserved CTD is a ligand-binding domain and senses the ergosterol level in the cell. Ergosterol binding represses its transcription activity, while dissociation of the ligand leads to relocalization of Upc2 from cytosol to nucleus for transcriptional activation. The C-terminal activation loop is essential for ligand binding and for transcriptional regulation. Our findings highlight that Upc2 represents a novel class of fungal zinc cluster transcription factors, which can serve as a target for the developments of antifungal therapeutics.
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Affiliation(s)
- Huiseon Yang
- College of Pharmacy, Chonnam National University, Gwangju 500-757, South Korea
| | - Junsen Tong
- College of Pharmacy, Chonnam National University, Gwangju 500-757, South Korea
| | - Chul Won Lee
- Department of Chemistry, Chonnam National University, Gwangju 500-757, South Korea
| | - Subin Ha
- College of Pharmacy, Chonnam National University, Gwangju 500-757, South Korea
| | - Soo Hyun Eom
- School of Life Science, Steitz Center for Structural Biology, and Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea
| | - Young Jun Im
- College of Pharmacy, Chonnam National University, Gwangju 500-757, South Korea
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