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López-Marmolejo AL, Hernández-Chávez MJ, Gutiérrez-Escobedo G, Selene Herrera-Basurto M, Mora-Montes HM, De Las Peñas A, Castaño I. Microevolution of Candida glabrata (Nakaseomyces glabrata) during an infection. Fungal Genet Biol 2024; 172:103891. [PMID: 38621582 DOI: 10.1016/j.fgb.2024.103891] [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: 09/20/2023] [Revised: 03/27/2024] [Accepted: 04/12/2024] [Indexed: 04/17/2024]
Abstract
Candida glabrata (Nakaseomyces glabrata) is an emergent and opportunistic fungal pathogen that colonizes and persists in different niches within its human host. In this work, we studied five clinical isolates from one patient (P7), that have a clonal origin, and all of which come from blood cultures except one, P7-3, obtained from a urine culture. We found phenotypic variation such as sensitivity to high temperature, oxidative stress, susceptibility to two classes of antifungal agents, and cell wall porosity. Only isolate P7-3 is highly resistant to the echinocandin caspofungin while the other four isolates from P7 are sensitive. However, this same isolate P7-3, is the only one that displays susceptibility to fluconazole (FLC), while the rest of the isolates are resistant to this antifungal. We sequenced the PDR1 gene which encodes a transcription factor required to induce the expression of several genes involved in the resistance to FLC and found that all the isolates encode for the same Pdr1 amino acid sequence except for the last isolate P7-5, which contains a single amino acid change, G1099C in the putative Pdr1 transactivation domain. Consistent with the resistance to FLC, we found that the CDR1 gene, encoding the main drug efflux pump in C. glabrata, is highly overexpressed in the FLC-resistant isolates, but not in the FLC-sensitive P7-3. In addition, the resistance to FLC observed in these isolates is dependent on the PDR1 gene. Additionally, we found that all P7 isolates have a different proportion of cell wall carbohydrates compared to our standard strains CBS138 and BG14. In P7 isolates, mannan is the most abundant cell wall component, whereas β-glucan is the most abundant component in our standard strains. Consistently, all P7 isolates have a relatively low cell wall porosity compared to our standard strains. These data show phenotypic and genotypic variability between clonal isolates from different niches within a single host, suggesting microevolution of C. glabrata during an infection.
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Affiliation(s)
- Ana L López-Marmolejo
- IPICYT, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José No. 2055, Col. Lomas 4a Sección, San Luis Potosí CP 78216, Mexico
| | - Marco J Hernández-Chávez
- IPICYT, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José No. 2055, Col. Lomas 4a Sección, San Luis Potosí CP 78216, Mexico
| | - Guadalupe Gutiérrez-Escobedo
- IPICYT, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José No. 2055, Col. Lomas 4a Sección, San Luis Potosí CP 78216, Mexico
| | - M Selene Herrera-Basurto
- IPICYT, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José No. 2055, Col. Lomas 4a Sección, San Luis Potosí CP 78216, Mexico
| | - Héctor M Mora-Montes
- Departamento de Biología, División de Ciencias Naturales, Universidad de Guanajuato, Noria Alta s/n Col. Noria Alta, Guanajuato, Gto CP36050, Mexico
| | - Alejandro De Las Peñas
- IPICYT, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José No. 2055, Col. Lomas 4a Sección, San Luis Potosí CP 78216, Mexico
| | - Irene Castaño
- IPICYT, División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José No. 2055, Col. Lomas 4a Sección, San Luis Potosí CP 78216, Mexico
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2
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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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3
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Chow EWL, Song Y, Wang H, Xu X, Gao J, Wang Y. Genome-wide profiling of piggyBac transposon insertion mutants reveals loss of the F 1F 0 ATPase complex causes fluconazole resistance in Candida glabrata. Mol Microbiol 2024; 121:781-797. [PMID: 38242855 DOI: 10.1111/mmi.15229] [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: 12/14/2023] [Revised: 01/04/2024] [Accepted: 01/07/2024] [Indexed: 01/21/2024]
Abstract
Invasive candidiasis caused by non-albicans species has been on the rise, with Candida glabrata emerging as the second most common etiological agent. Candida glabrata possesses an intrinsically lower susceptibility to azoles and an alarming propensity to rapidly develop high-level azole resistance during treatment. In this study, we have developed an efficient piggyBac (PB) transposon-mediated mutagenesis system in C. glabrata to conduct genome-wide genetic screens and applied it to profile genes that contribute to azole resistance. When challenged with the antifungal drug fluconazole, PB insertion into 270 genes led to significant resistance. A large subset of these genes has a role in the mitochondria, including almost all genes encoding the subunits of the F1F0 ATPase complex. We show that deleting ATP3 or ATP22 results in increased azole resistance but does not affect susceptibility to polyenes and echinocandins. The increased azole resistance is due to increased expression of PDR1 that encodes a transcription factor known to promote drug efflux pump expression. Deleting PDR1 in the atp3Δ or atp22Δ mutant resulted in hypersensitivity to fluconazole. Our results shed light on the mechanisms contributing to azole resistance in C. glabrata. This PB transposon-mediated mutagenesis system can significantly facilitate future genome-wide genetic screens.
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Affiliation(s)
- Eve W L Chow
- A*STAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science and Technology Research (A*STAR), Singapore, Singapore
| | - Yabing Song
- School of Life Sciences, Tsinghua University, Beijing, China
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Haitao Wang
- A*STAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science and Technology Research (A*STAR), Singapore, Singapore
| | - Xiaoli Xu
- A*STAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science and Technology Research (A*STAR), Singapore, Singapore
| | - Jiaxin Gao
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yue Wang
- A*STAR Infectious Diseases Labs (A*STAR ID Labs), Agency for Science and Technology Research (A*STAR), Singapore, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
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4
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Maroc L, Shaker H, Shapiro RS. Functional genetic characterization of stress tolerance and biofilm formation in Nakaseomyces ( Candida) glabrata via a novel CRISPR activation system. mSphere 2024; 9:e0076123. [PMID: 38265239 PMCID: PMC10900893 DOI: 10.1128/msphere.00761-23] [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: 12/07/2023] [Accepted: 12/13/2023] [Indexed: 01/25/2024] Open
Abstract
The overexpression of genes frequently arises in Nakaseomyces (formerly Candida) glabrata via gain-of-function mutations, gene duplication, or aneuploidies, with important consequences on pathogenesis traits and antifungal drug resistance. This highlights the need to develop specific genetic tools to mimic and study genetic amplification in this important fungal pathogen. Here, we report the development, validation, and applications of the first clustered regularly interspaced short palindromic repeats (CRISPR) activation (CRISPRa) system in N. glabrata for targeted genetic overexpression. Using this system, we demonstrate the ability of CRISPRa to drive high levels of gene expression in N. glabrata, and further assess optimal guide RNA targeting for robust overexpression. We demonstrate the applications of CRISPRa to overexpress genes involved in fungal pathogenesis and drug resistance and detect corresponding phenotypic alterations in these key traits, including the characterization of novel phenotypes. Finally, we capture strain variation using our CRISPRa system in two commonly used N. glabrata genetic backgrounds. Together, this tool will expand our capacity for functional genetic overexpression in this pathogen, with numerous possibilities for future applications.IMPORTANCENakaseomyces (formerly Candida) glabrata is an important fungal pathogen that is now the second leading cause of candidiasis infections. A common strategy that this pathogen employs to resist antifungal treatment is through the upregulation of gene expression, but we have limited tools available to study this phenomenon. Here, we develop, optimize, and apply the use of CRISPRa as a means to overexpress genes in N. glabrata. We demonstrate the utility of this system to overexpress key genes involved in antifungal susceptibility, stress tolerance, and biofilm growth. This tool will be an important contribution to our ability to study the biology of this important fungal pathogen.
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Affiliation(s)
- Laetitia Maroc
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada
| | - Hajer Shaker
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada
| | - Rebecca S Shapiro
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Canada
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Misas E, Seagle E, Jenkins EN, Rajeev M, Hurst S, Nunnally NS, Bentz ML, Lyman MM, Berkow E, Harrison LH, Schaffner W, Markus TM, Pierce R, Farley MM, Chow NA, Lockhart SR, Litvintseva AP. Genomic description of acquired fluconazole- and echinocandin-resistance in patients with serial Candida glabrata isolates. J Clin Microbiol 2024; 62:e0114023. [PMID: 38265207 PMCID: PMC10865870 DOI: 10.1128/jcm.01140-23] [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: 09/06/2023] [Accepted: 11/29/2023] [Indexed: 01/25/2024] Open
Abstract
Candida glabrata is one of the most common causes of systemic candidiasis, often resistant to antifungal medications. To describe the genomic context of emerging resistance, we conducted a retrospective analysis of 82 serially collected isolates from 33 patients from population-based candidemia surveillance in the United States. We used whole-genome sequencing to determine the genetic relationships between isolates obtained from the same patient. Phylogenetic analysis demonstrated that isolates from 29 patients were clustered by patient. The median SNPs between isolates from the same patient was 30 (range: 7-96 SNPs), while unrelated strains infected four patients. Twenty-one isolates were resistant to echinocandins, and 24 were resistant to fluconazole. All echinocandin-resistant isolates carried a mutation either in the FKS1 or FKS2 HS1 region. Of the 24 fluconazole-resistant isolates, 17 (71%) had non-synonymous polymorphisms in the PDR1 gene, which were absent in susceptible isolates. In 11 patients, a genetically related resistant isolate was collected after recovering susceptible isolates, indicating in vivo acquisition of resistance. These findings allowed us to estimate the intra-host diversity of C. glabrata and propose an upper boundary of 96 SNPs for defining genetically related isolates, which can be used to assess donor-to-host transmission, nosocomial transmission, or acquired resistance. IMPORTANCE In our study, mutations associated to azole resistance and echinocandin resistance were detected in Candida glabrata isolates using a whole-genome sequence. C. glabrata is the second most common cause of candidemia in the United States, which rapidly acquires resistance to antifungals, in vitro and in vivo.
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Affiliation(s)
- E. Misas
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - E. Seagle
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - E. N. Jenkins
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
- ASRT, Inc., Atlanta, Georgia, USA
| | - M. Rajeev
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - S. Hurst
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - N. S. Nunnally
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - M. L. Bentz
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - M. M. Lyman
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - E. Berkow
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - L. H. Harrison
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - W. Schaffner
- Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - T. M. Markus
- Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - R. Pierce
- Oregon Public Health Division, Oregon Health Authority, Portland, USA
| | - M. M. Farley
- Emory University School of Medicine, Decatur, Georgia, USA
| | - N. A. Chow
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - S. R. Lockhart
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - A. P. Litvintseva
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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6
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Czajka KM, Venkataraman K, Brabant-Kirwan D, Santi SA, Verschoor C, Appanna VD, Singh R, Saunders DP, Tharmalingam S. Molecular Mechanisms Associated with Antifungal Resistance in Pathogenic Candida Species. Cells 2023; 12:2655. [PMID: 37998390 PMCID: PMC10670235 DOI: 10.3390/cells12222655] [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: 10/17/2023] [Revised: 11/14/2023] [Accepted: 11/17/2023] [Indexed: 11/25/2023] Open
Abstract
Candidiasis is a highly pervasive infection posing major health risks, especially for immunocompromised populations. Pathogenic Candida species have evolved intrinsic and acquired resistance to a variety of antifungal medications. The primary goal of this literature review is to summarize the molecular mechanisms associated with antifungal resistance in Candida species. Resistance can be conferred via gain-of-function mutations in target pathway genes or their transcriptional regulators. Therefore, an overview of the known gene mutations is presented for the following antifungals: azoles (fluconazole, voriconazole, posaconazole and itraconazole), echinocandins (caspofungin, anidulafungin and micafungin), polyenes (amphotericin B and nystatin) and 5-fluorocytosine (5-FC). The following mutation hot spots were identified: (1) ergosterol biosynthesis pathway mutations (ERG11 and UPC2), resulting in azole resistance; (2) overexpression of the efflux pumps, promoting azole resistance (transcription factor genes: tac1 and mrr1; transporter genes: CDR1, CDR2, MDR1, PDR16 and SNQ2); (3) cell wall biosynthesis mutations (FKS1, FKS2 and PDR1), conferring resistance to echinocandins; (4) mutations of nucleic acid synthesis/repair genes (FCY1, FCY2 and FUR1), resulting in 5-FC resistance; and (5) biofilm production, promoting general antifungal resistance. This review also provides a summary of standardized inhibitory breakpoints obtained from international guidelines for prominent Candida species. Notably, N. glabrata, P. kudriavzevii and C. auris demonstrate fluconazole resistance.
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Affiliation(s)
- Karolina M. Czajka
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
| | - Krishnan Venkataraman
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
| | | | - Stacey A. Santi
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Chris Verschoor
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Vasu D. Appanna
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
| | - Ravi Singh
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Deborah P. Saunders
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Sujeenthar Tharmalingam
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
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7
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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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8
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Nakano K, Okamoto M, Takahashi-Nakaguchi A, Sasamoto K, Yamaguchi M, Chibana H. Evaluation of Antifungal Selective Toxicity Using Candida glabrata ERG25 and Human SC4MOL Knock-In Strains. J Fungi (Basel) 2023; 9:1035. [PMID: 37888291 PMCID: PMC10607794 DOI: 10.3390/jof9101035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 10/28/2023] Open
Abstract
With only four classes of antifungal drugs available for the treatment of invasive systemic fungal infections, the number of resistant fungi is increasing, highlighting the urgent need for novel antifungal drugs. Ergosterol, an essential component of cell membranes, and its synthetic pathway have been targeted for antifungal drug development. Sterol-C4-methyl monooxygenase (Erg25p), which is a greater essential target than that of existing drugs, represents a promising drug target. However, the development of antifungal drugs must consider potential side effects, emphasizing the importance of evaluating their selective toxicity against fungi. In this study, we knocked in ERG25 of Candida glabrata and its human ortholog, SC4MOL, in ERG25-deleted Saccharomyces cerevisiae. Utilizing these strains, we evaluated 1181-0519, an Erg25p inhibitor, that exhibited selective toxicity against the C. glabrata ERG25 knock-in strain. Furthermore, 1181-0519 demonstrated broad-spectrum antifungal activity against pathogenic Candida species, including Candida auris. The approach of utilizing a gene that is functionally conserved between yeast and humans and subsequently screening for molecular target drugs enables the identification of selective inhibitors for both species.
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Affiliation(s)
- Keiko Nakano
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | - Michiyo Okamoto
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | | | - Kaname Sasamoto
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | - Masashi Yamaguchi
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | - Hiroji Chibana
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
- School of Medicine, Niigata University, Niigata 951-8510, Japan
- Faculty of Medicine, University of the Ryukyus, Okinawa 903-0125, Japan
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9
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Gale AN, Pavesic MW, Nickels TJ, Xu Z, Cormack BP, Cunningham KW. Redefining pleiotropic drug resistance in a pathogenic yeast: Pdr1 functions as a sensor of cellular stresses in Candida glabrata. mSphere 2023; 8:e0025423. [PMID: 37358297 PMCID: PMC10449514 DOI: 10.1128/msphere.00254-23] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 05/09/2023] [Indexed: 06/27/2023] Open
Abstract
Candida glabrata is a prominent opportunistic fungal pathogen of humans. The increasing incidence of C. glabrata infections is attributed to both innate and acquired resistance to antifungals. Previous studies suggest the transcription factor Pdr1 and several target genes encoding ABC transporters are critical elements of pleiotropic defense against azoles and other antifungals. This study utilizes Hermes transposon insertion profiling to investigate Pdr1-independent and Pdr1-dependent mechanisms that alter susceptibility to the frontline antifungal fluconazole. Several new genes were found to alter fluconazole susceptibility independent of Pdr1 (CYB5, SSK1, SSK2, HOG1, TRP1). A bZIP transcription repressor of mitochondrial function (CIN5) positively regulated Pdr1 while hundreds of genes encoding mitochondrial proteins were confirmed as negative regulators of Pdr1. The antibiotic oligomycin activated Pdr1 and antagonized fluconazole efficacy likely by interfering with mitochondrial processes in C. glabrata. Unexpectedly, disruption of many 60S ribosomal proteins also activated Pdr1, thus mimicking the effects of the mRNA translation inhibitors. Cycloheximide failed to fully activate Pdr1 in a cycloheximide-resistant Rpl28-Q38E mutant. Similarly, fluconazole failed to fully activate Pdr1 in a strain expressing a low-affinity variant of Erg11. Fluconazole activated Pdr1 with very slow kinetics that correlated with the delayed onset of cellular stress. These findings are inconsistent with the idea that Pdr1 directly senses xenobiotics and support an alternative hypothesis where Pdr1 senses cellular stresses that arise only after engagement of xenobiotics with their targets. IMPORTANCE Candida glabrata is an opportunistic pathogenic yeast that causes discomfort and death. Its incidence has been increasing because of natural defenses to our common antifungal medications. This study explores the entire genome for impacts on resistance to fluconazole. We find several new and unexpected genes can impact susceptibility to fluconazole. Several antibiotics can also alter the efficacy of fluconazole. Most importantly, we find that Pdr1-a key determinant of fluconazole resistance-is not regulated directly through binding of fluconazole and instead is regulated indirectly by sensing the cellular stresses caused by fluconazole blockage of sterol biosynthesis. This new understanding of drug resistance mechanisms could improve the outcomes of current antifungals and accelerate the development of novel therapeutics.
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Affiliation(s)
- Andrew N. Gale
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Matthew W. Pavesic
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Timothy J. Nickels
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Zhuwei Xu
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Brendan P. Cormack
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Kyle W. Cunningham
- Department of Biology, Johns Hopkins University, Baltimore, Maryland, USA
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10
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Lee Y, Robbins N, Cowen LE. Molecular mechanisms governing antifungal drug resistance. NPJ ANTIMICROBIALS AND RESISTANCE 2023; 1:5. [PMID: 38686214 PMCID: PMC11057204 DOI: 10.1038/s44259-023-00007-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/17/2023] [Indexed: 05/02/2024]
Abstract
Fungal pathogens are a severe public health problem. The leading causative agents of systemic fungal infections include species from the Candida, Cryptococcus, and Aspergillus genera. As opportunistic pathogens, these fungi are generally harmless in healthy hosts; however, they can cause significant morbidity and mortality in immunocompromised patients. Despite the profound impact of pathogenic fungi on global human health, the current antifungal armamentarium is limited to only three major classes of drugs, all of which face complications, including host toxicity, unfavourable pharmacokinetics, or limited spectrum of activity. Further exacerbating this issue is the growing prevalence of antifungal-resistant infections and the emergence of multidrug-resistant pathogens. In this review, we discuss the diverse strategies employed by leading fungal pathogens to evolve antifungal resistance, including drug target alterations, enhanced drug efflux, and induction of cellular stress response pathways. Such mechanisms of resistance occur through diverse genetic alterations, including point mutations, aneuploidy formation, and epigenetic changes given the significant plasticity observed in many fungal genomes. Additionally, we highlight recent literature surrounding the mechanisms governing resistance in emerging multidrug-resistant pathogens including Candida auris and Candida glabrata. Advancing our knowledge of the molecular mechanisms by which fungi adapt to the challenge of antifungal exposure is imperative for designing therapeutic strategies to tackle the emerging threat of antifungal resistance.
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Affiliation(s)
- Yunjin Lee
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1 Canada
| | - Nicole Robbins
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1 Canada
| | - Leah E. Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5G 1M1 Canada
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11
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Torabiardekani N, Karami F, Khorram M, Zare A, Kamkar M, Zomorodian K, Zareshahrabadi Z. Encapsulation of Zataria multiflora essential oil in polyvinyl alcohol/chitosan/gelatin thermo-responsive hydrogel: Synthesis, physico-chemical properties, and biological investigations. Int J Biol Macromol 2023:125073. [PMID: 37245771 DOI: 10.1016/j.ijbiomac.2023.125073] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 04/25/2023] [Accepted: 05/22/2023] [Indexed: 05/30/2023]
Abstract
Zataria multiflora essential oil is a natural volatile plant product whose therapeutic applications require a delivery platform. Biomaterial-based hydrogels have been extensively used in biomedical applications, and they are promising platforms to encapsulate essential oils. Among different hydrogels, intelligent hydrogels have recently attracted many interests because of their response to environmental stimuli such as temperature. Herein, Zataria multiflora essential oil is encapsulated in a polyvinyl alcohol/chitosan/gelatin hydrogel as a positive thermo-responsive and antifungal platform. According to the optical microscopic image, the encapsulated spherical essential oil droplets reveal a mean size of 1.10 ± 0.64 μm, which are in consistent with the SEM imaging results. Encapsulation efficacy and loading capacity are 98.66 % and 12.98 %, respectively. These results confirm the successful efficient encapsulation of the Zataria multiflora essential oil within the hydrogel. The chemical compositions of the Zataria multiflora essential oil and the fabricated hydrogel are analyzed by gas chromatography-mass spectroscopy (GC-MS) and Fourier transform infrared (FTIR) techniques. It is found that thymol (44.30 %) and γ-terpinene (22.62 %) are the main constituents of the Zataria multiflora essential oil. The produced hydrogel inhibits the metabolic activity of Candida albicans biofilms (~60-80 %), which can be related to the antifungal activity of the essential oil constituents and chitosan. Based on the rheological results, the produced thermo-responsive hydrogel shows a gel-sol viscoelastic transition at a temperature of 24.5 °C. This transition leads to a facile release of the loaded essential oil. The release test depicts that about 30 % of Zataria multiflora essential oil is released during the first 16 min. In addition, 2, 5-diphenyl-2H-tetrazolium bromide (MTT) assay demonstrates that the designed thermo-sensitive formulation is biocompatible with high cell viability (over 96 %). The fabricated hydrogel can be deemed as a potential intelligent drug delivery platform for controlling cutaneous candidiasis due to antifungal effectiveness and less toxicity, which can be a promising alternative to traditional drug delivery systems.
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Affiliation(s)
| | - Forough Karami
- Central Research Laboratory, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran; Chemistry Department, Yasouj University, Yasouj, Iran
| | - Mohammad Khorram
- School of Chemical and Petroleum Engineering, Shiraz University, Shiraz, Iran
| | - Alireza Zare
- Department of Chemical Engineering, Shiraz Branch, Islamic Azad University, Shiraz, Iran
| | - Milad Kamkar
- Department of Chemical Engineering and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Canada
| | - Kamiar Zomorodian
- Department of Medical Parasitology and Mycology, Shiraz University of Medical Sciences, Shiraz, Iran; Basic Sciences in Infectious Diseases Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Zahra Zareshahrabadi
- Basic Sciences in Infectious Diseases Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
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12
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Osset-Trénor P, Pascual-Ahuir A, Proft M. Fungal Drug Response and Antimicrobial Resistance. J Fungi (Basel) 2023; 9:jof9050565. [PMID: 37233275 DOI: 10.3390/jof9050565] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/27/2023] [Accepted: 05/12/2023] [Indexed: 05/27/2023] Open
Abstract
Antifungal resistance is a growing concern as it poses a significant threat to public health. Fungal infections are a significant cause of morbidity and mortality, especially in immunocompromised individuals. The limited number of antifungal agents and the emergence of resistance have led to a critical need to understand the mechanisms of antifungal drug resistance. This review provides an overview of the importance of antifungal resistance, the classes of antifungal agents, and their mode of action. It highlights the molecular mechanisms of antifungal drug resistance, including alterations in drug modification, activation, and availability. In addition, the review discusses the response to drugs via the regulation of multidrug efflux systems and antifungal drug-target interactions. We emphasize the importance of understanding the molecular mechanisms of antifungal drug resistance to develop effective strategies to combat the emergence of resistance and highlight the need for continued research to identify new targets for antifungal drug development and explore alternative therapeutic options to overcome resistance. Overall, an understanding of antifungal drug resistance and its mechanisms will be indispensable for the field of antifungal drug development and clinical management of fungal infections.
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Affiliation(s)
- Paloma Osset-Trénor
- Department of Biotechnology, Instituto de Biología Molecular y Celular de Plantas IBMCP, Universidad Politécnica de Valencia, 46022 Valencia, Spain
| | - Amparo Pascual-Ahuir
- Department of Biotechnology, Instituto de Biología Molecular y Celular de Plantas IBMCP, Universidad Politécnica de Valencia, 46022 Valencia, Spain
| | - Markus Proft
- Department of Molecular and Cellular Pathology and Therapy, Instituto de Biomedicina de Valencia IBV-CSIC, Consejo Superior de Investigaciones Científicas CSIC, 46010 Valencia, Spain
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13
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Gale AN, Pavesic MW, Nickels TJ, Xu Z, Cormack BP, Cunningham KW. Redefining Pleiotropic Drug Resistance in a Pathogenic Yeast: Pdr1 Functions as a Sensor of Cellular Stresses in Candida glabrata. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.07.539747. [PMID: 37214952 PMCID: PMC10197522 DOI: 10.1101/2023.05.07.539747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Candida glabrata is a prominent opportunistic fungal pathogen of humans. The increasing incidence of C. glabrata infections is attributed to both innate and acquired resistance to antifungals. Previous studies suggest the transcription factor Pdr1 and several target genes encoding ABC transporters are critical elements of pleiotropic defense against azoles and other antifungals. This study utilizes Hermes transposon insertion profiling to investigate Pdr1-independent and Pdr1-dependent mechanisms that alter susceptibility to the frontline antifungal fluconazole. Several new genes were found to alter fluconazole susceptibility independent of Pdr1 ( CYB5 , SSK1 , SSK2 , HOG1 , TRP1 ). A bZIP transcription repressor of mitochondrial function ( CIN5 ) positively regulated Pdr1 while hundreds of genes encoding mitochondrial proteins were confirmed as negative regulators of Pdr1. The antibiotic oligomycin activated Pdr1 and antagonized fluconazole efficacy likely by interfering with mitochondrial processes in C. glabrata . Unexpectedly, disruption of many 60S ribosomal proteins also activated Pdr1, thus mimicking the effects of the mRNA translation inhibitors. Cycloheximide failed to fully activate Pdr1 in a cycloheximide-resistant Rpl28-Q38E mutant. Similarly, fluconazole failed to fully activate Pdr1 in a strain expressing a low-affinity variant of Erg11. Fluconazole activated Pdr1 with very slow kinetics that correlated with the delayed onset of cellular stress. These findings are inconsistent with the idea that Pdr1 directly senses xenobiotics and support an alternative hypothesis where Pdr1 senses cellular stresses that arise only after engagement of xenobiotics with their targets. Importance Candida glabrata is an opportunistic pathogenic yeast that causes discomfort and death. Its incidence has been increasing because of natural defenses to our common antifungal medications. This study explores the entire genome for impacts on resistance to fluconazole. We find several new and unexpected genes can impact susceptibility to fluconazole. Several antibiotics can also alter the efficacy of fluconazole. Most importantly, we find that Pdr1 - a key determinant of fluconazole resistance - is not regulated directly through binding of fluconazole and instead is regulated indirectly by sensing the cellular stresses caused by fluconazole blockage of sterol biosynthesis. This new understanding of drug resistance mechanisms could improve the outcomes of current antifungals and accelerate the development of novel therapeutics.
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14
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Okamoto M, Nakano K, Takahashi-Nakaguchi A, Sasamoto K, Yamaguchi M, Teixeira MC, Chibana H. In Candida glabrata, ERMES Component GEM1 Controls Mitochondrial Morphology, mtROS, and Drug Efflux Pump Expression, Resulting in Azole Susceptibility. J Fungi (Basel) 2023; 9:jof9020240. [PMID: 36836353 PMCID: PMC9965728 DOI: 10.3390/jof9020240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 02/05/2023] [Accepted: 02/08/2023] [Indexed: 02/16/2023] Open
Abstract
Mitochondrial dysfunction or morphological abnormalities in human pathogenic fungi are known to contribute to azole resistance; however, the underlying molecular mechanisms are unknown. In this study, we investigated the link between mitochondrial morphology and azole resistance in Candida glabrata, which is the second most common cause of human candidiasis worldwide. The ER-mitochondrial encounter structure (ERMES) complex is thought to play an important role in the mitochondrial dynamics necessary for mitochondria to maintain their function. Of the five components of the ERMES complex, deletion of GEM1 increased azole resistance. Gem1 is a GTPase that regulates the ERMES complex activity. Point mutations in GEM1 GTPase domains were sufficient to confer azole resistance. The cells lacking GEM1 displayed abnormalities in mitochondrial morphology, increased mtROS levels, and increased expression of azole drug efflux pumps encoded by CDR1 and CDR2. Interestingly, treatment with N-acetylcysteine (NAC), an antioxidant, reduced ROS production and the expression of CDR1 in Δgem1 cells. Altogether, the absence of Gem1 activity caused an increase in mitochondrial ROS concentration, leading to Pdr1-dependent upregulation of the drug efflux pump Cdr1, resulting in azole resistance.
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Affiliation(s)
- Michiyo Okamoto
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | - Keiko Nakano
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | | | - Kaname Sasamoto
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | - Masashi Yamaguchi
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
| | - Miguel Cacho Teixeira
- iBB—Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisbon, Portugal
| | - Hiroji Chibana
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan
- Correspondence:
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15
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Conway TP, Moye-Rowley WS. Conditional Protein Depletion in the Analysis of Antifungal Drug Resistance in Candida glabrata. Methods Mol Biol 2023; 2658:191-200. [PMID: 37024703 DOI: 10.1007/978-1-0716-3155-3_13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Abstract
This chapter illustrates a method to generate Candida glabrata conditional depletion mutants for SNF2, an ATPase subunit of the SWI/SNF chromatin remodeling complex with potential roles in the response to azole drugs. The strategy employed utilizes a plant-specific proteolysis pathway which allows for the rapid degradation of a target protein in the presence of the phytohormone, auxin. The steps taken to generate strains expressing the auxin-inducible plant F-box protein, Tir1, and in which the auxin-binding target, IAA17, is C-terminally fused to Snf2 are described. This acute depletion strategy is suitable for studying the effects of the loss of growth-critical proteins. The rapid depletion afforded by the auxin-induced degradation avoids the potential complications of a null allele causing a severe growth defect and allows a more rapid assessment of the consequences of reduced levels of a protein of interest.
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Affiliation(s)
- Thomas P Conway
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - W Scott Moye-Rowley
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
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16
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Simonicova L, Moye-Rowley WS. Characterizing Candida glabrata Pdr1, a Hyperactive Transcription Factor Involved in Azole Resistance. Methods Mol Biol 2023; 2658:169-179. [PMID: 37024701 DOI: 10.1007/978-1-0716-3155-3_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/08/2023]
Abstract
This chapter illustrates how to prepare isogenic strains carrying gain-of-function forms of transcription factor Pdr1 in the human pathogen Candida glabrata. Simple steps are described that lead from a characterized plasmid-borne PDR1-GOF allele to its integration into the yeast genome in a markerless manner. Pdr1-GOF strains constructed by this approach are suitable for virulence studies in an animal host.
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Affiliation(s)
- Lucia Simonicova
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - W Scott Moye-Rowley
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
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17
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Pais P, Galocha M, Takahashi-Nakaguchi A, Chibana H, Teixeira MC. Multiple genome analysis of Candida glabrata clinical isolates renders new insights into genetic diversity and drug resistance determinants. MICROBIAL CELL (GRAZ, AUSTRIA) 2022; 9:174-189. [PMID: 36448018 PMCID: PMC9662024 DOI: 10.15698/mic2022.11.786] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 10/06/2022] [Accepted: 10/10/2022] [Indexed: 11/07/2023]
Abstract
The emergence of drug resistance significantly hampers the treatment of human infections, including those caused by fungal pathogens such as Candida species. Candida glabrata ranks as the second most common cause of candidiasis worldwide, supported by rapid acquisition of resistance to azole and echinocandin antifungals frequently prompted by single nucleotide polymorphisms (SNPs) in resistance associated genes, such as PDR1 (azole resistance) or FKS1/2 (echinocandin resistance). To determine the frequency of polymorphisms and genome rearrangements as the possible genetic basis of C. glabrata drug resistance, we assessed genomic variation across 94 globally distributed isolates with distinct resistance phenotypes, whose sequence is deposited in GenBank. The genomes of three additional clinical isolates were sequenced, in this study, including two azole resistant strains that did not display Gain-Of-Function (GOF) mutations in the transcription factor encoding gene PDR1. Genomic variations in susceptible isolates were used to screen out variants arising from genome diversity and to identify variants exclusive to resistant isolates. More than half of the azole or echinocandin resistant isolates do not possess exclusive polymorphisms in PDR1 or FKS1/2, respectively, providing evidence of alternative genetic basis of antifungal resistance. We also identified copy number variations consistently affecting a subset of chromosomes. Overall, our analysis of the genomic and phenotypic variation across isolates allowed to pinpoint, in a genome-wide scale, genetic changes enriched specifically in antifungal resistant strains, which provides a first step to identify additional determinants of antifungal resistance. Specifically, regarding the newly sequenced strains, a set of mutations/genes are proposed to underlie the observed unconventional azole resistance phenotype.
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Affiliation(s)
- Pedro Pais
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Portugal
| | - Mónica Galocha
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Portugal
| | | | - Hiroji Chibana
- Medical Mycology Research Center (MMRC), Chiba University, Chiba, Japan
| | - Miguel C. Teixeira
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
- iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Portugal
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18
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Galocha M, Viana R, Pais P, Silva-Dias A, Cavalheiro M, Miranda IM, Van Ende M, Souza CS, Costa C, Branco J, Soares CM, Van Dijck P, Rodrigues AG, Teixeira MC. Genomic evolution towards azole resistance in Candida glabrata clinical isolates unveils the importance of CgHxt4/6/7 in azole accumulation. Commun Biol 2022; 5:1118. [PMID: 36271293 PMCID: PMC9587243 DOI: 10.1038/s42003-022-04087-0] [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: 08/04/2021] [Accepted: 10/11/2022] [Indexed: 11/09/2022] Open
Abstract
The increasing prevalence of candidosis caused by Candida glabrata is related to its ability to acquire azole resistance. Although azole resistance mechanisms are well known, the mechanisms for azole import into fungal cells have remained obscure. In this work, we have characterized two hexose transporters in C. glabrata and further investigate their role as potential azole importers. Three azole susceptible C. glabrata clinical isolates were evolved towards azole resistance and the acquired resistance phenotype was found to be independent of CgPDR1 or CgERG11 mutations. Through whole-genome sequencing, CgHXT4/6/7 was found to be mutated in the three evolved strains, when compared to their susceptible parents. CgHxt4/6/7 and the 96% identical CgHxt6/7 were found to confer azole susceptibility and increase azole accumulation in C. glabrata cells, strikingly rescuing the susceptibility phenotype imposed by CgPDR1 deletion, while the identified loss-of-function mutation in CgHXT4/6/7, leads to increased azole resistance. In silico docking analysis shows that azoles display a strong predicted affinity for the glucose binding site of CgHxt4/6/7. Altogether, we hypothesize that hexose transporters, such as CgHxt4/6/7 and CgHxt6/7, may constitute a family of azole importers, involved in clinical drug resistance in fungal pathogens, and constituting promising targets for improved antifungal therapy. Mutations in the hexose transporter, CgHXT4/6/7, contribute to increased antifungal (azole) resistance in the fungal pathogen, Candida glabrata, potentially by influencing azole accumulation.
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Affiliation(s)
- Mónica Galocha
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisbon, Portugal.,Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Romeu Viana
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisbon, Portugal.,Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Pedro Pais
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisbon, Portugal.,Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Ana Silva-Dias
- Department of Microbiology, Faculty of Medicine, University of Porto, Porto, Portugal.,CINTESIS - Center for Health Technology and Services Research, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Mafalda Cavalheiro
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisbon, Portugal.,Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Isabel M Miranda
- Department of Microbiology, Faculty of Medicine, University of Porto, Porto, Portugal.,CINTESIS - Center for Health Technology and Services Research, Faculty of Medicine, University of Porto, Porto, Portugal.,Cardiovascular R&D Center, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Mieke Van Ende
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium.,VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| | - Caio S Souza
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Catarina Costa
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisbon, Portugal.,Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Joana Branco
- Department of Microbiology, Faculty of Medicine, University of Porto, Porto, Portugal.,CINTESIS - Center for Health Technology and Services Research, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Cláudio M Soares
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Patrick Van Dijck
- Laboratory of Molecular Cell Biology, Department of Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium.,VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| | - Acácio G Rodrigues
- Department of Microbiology, Faculty of Medicine, University of Porto, Porto, Portugal. .,CINTESIS - Center for Health Technology and Services Research, Faculty of Medicine, University of Porto, Porto, Portugal.
| | - Miguel C Teixeira
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal. .,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisbon, Portugal. .,Associate Laboratory i4HB-Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.
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19
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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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20
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Vu BG, Moye-Rowley WS. Nonidentical function of Upc2A binding sites in the Candida glabrata CDR1 promoter. Genetics 2022; 222:iyac135. [PMID: 36063046 PMCID: PMC9526049 DOI: 10.1093/genetics/iyac135] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 08/15/2022] [Indexed: 01/04/2023] Open
Abstract
Increased expression of the Candida glabrata CDR1 gene, encoding an ATP-binding cassette membrane transporter, is routinely observed in fluconazole-resistant isolates of this pathogenic yeast. CDR1 transcription has been well-documented to be due to activity of the Zn2Cys6 zinc cluster-containing transcription factor Pdr1. Gain-of-function mutations in the gene encoding this factor are the most commonly observed cause of fluconazole hyper-resistance in clinical isolates. We have recently found that the sterol-responsive transcription factor Upc2A also acts to control CDR1 transcription, providing a direct link between ergosterol biosynthesis and expression of Pdr1 target genes. While this earlier work implicated Upc2A as an activator of CDR1 transcription, our further analyses revealed the presence of a second Upc2A binding site that negatively regulated CDR1 expression. This Upc2A binding site designated a sterol-responsive element (SRE) was found to have significant lower affinity for Upc2A DNA-binding than the previously described SRE. This new SRE was designated SRE2 while the original, positively acting site was named SRE1. A mutant version of SRE2 prevented in vitro DNA-binding by recombinant Upc2A and, when introduced into the CDR1 promoter, caused decreased fluconazole susceptibility and increased CDR1 expression. This negative effect caused by loss of SRE2 was shown to be Pdr1 independent, consistent with the presence of at least one additional activator of CDR1 transcription. The ability of Upc2A to exert either positive or negative effects on gene expression resembles behavior of mammalian nuclear receptor proteins and reveals an unexpectedly complex nature for SRE effects on gene regulation.
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Affiliation(s)
- Bao Gia Vu
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - William Scott Moye-Rowley
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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21
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Edlind T, Katiyar S. Intrinsically High Resistance of Candida glabrata to Hydrogen Peroxide and Its Reversal in a Fluconazole-Resistant Mutant. Antimicrob Agents Chemother 2022; 66:e0072122. [PMID: 35916516 PMCID: PMC9487529 DOI: 10.1128/aac.00721-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Affiliation(s)
- Tom Edlind
- MicrobiType LLC, Wyndmoor, Pennsylvania, USA
| | - Santosh Katiyar
- Drexel University College of Medicine, Philadelphia, Pennsylvania, USA
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22
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Merdan O, Şişman AS, Aksoy SA, Kızıl S, Tüzemen NÜ, Yılmaz E, Ener B. Investigation of the Defective Growth Pattern and Multidrug Resistance in a Clinical Isolate of Candida glabrata Using Whole-Genome Sequencing and Computational Biology Applications. Microbiol Spectr 2022; 10:e0077622. [PMID: 35867406 PMCID: PMC9430859 DOI: 10.1128/spectrum.00776-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 06/16/2022] [Indexed: 11/20/2022] Open
Abstract
Candida glabrata is increasingly isolated from blood cultures, and multidrug-resistant isolates have important implications for therapy. This study describes a cholesterol-dependent clinical C. glabrata isolate (ML72254) that did not grow without blood (containing cholesterol) on routine mycological media and that showed azole and amphotericin B (AmB) resistance. Matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) and whole-genome sequencing (WGS) were used for species identification. A modified Etest method (Mueller-Hinton agar supplemented with 5% sheep blood) was used for antifungal susceptibility testing. WGS data were processed via the Galaxy platform, and the genomic variations of ML72254 were retrieved. A computational biology workflow utilizing web-based applications (PROVEAN, AlphaFold Colab, and Missense3D) was constructed to predict possible deleterious effects of these missense variations on protein functions. The predictive ability of this workflow was tested with previously reported missense variations in ergosterol synthesis genes of C. glabrata. ML72254 was identified as C. glabrata sensu stricto with MALDI-TOF, and WGS confirmed this identification. The MICs of fluconazole, voriconazole, and amphotericin B were >256, >32, and >32 μg/mL, respectively. A novel frameshift mutation in the ERG1 gene (Pro314fs) and many missense variations were detected in the ergosterol synthesis genes. None of the missense variations in the ML72254 ergosterol synthesis genes were deleterious, and the Pro314fs mutation was identified as the causative molecular change for a cholesterol-dependent and multidrug-resistant phenotype. This study verified that web-based computational biology solutions can be powerful tools for examining the possible impacts of missense mutations in C. glabrata. IMPORTANCE In this study, a cholesterol-dependent C. glabrata clinical isolate that confers azole and AmB resistance was investigated using artificial intelligence (AI) technologies and cloud computing applications. This is the first of the known cholesterol-dependent C. glabrata isolate to be found in Turkey. Cholesterol-dependent C. glabrata isolates are rarely isolated in clinical samples; they can easily be overlooked during routine laboratory procedures. Microbiologists therefore need to be alert when discrepancies occur between microscopic examination and growth on routine media. In addition, because these isolates confer antifungal resistance, patient management requires extra care.
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Affiliation(s)
- Osman Merdan
- Department of Medical Microbiology, Faculty of Medicine, Bursa Uludağ University, Bursa, Turkey
| | - Ayşe Sena Şişman
- Department of Clinical Microbiology and Infectious Diseases, Faculty of Medicine, Bursa Uludağ University, Bursa, Turkey
| | - Seçil Ak Aksoy
- İnegöl Vocational School, Bursa Uludağ University, Bursa, Turkey
| | - Samet Kızıl
- Department of Medical Microbiology, Faculty of Medicine, Bursa Uludağ University, Bursa, Turkey
| | - Nazmiye Ülkü Tüzemen
- Department of Medical Microbiology, Faculty of Medicine, Bursa Uludağ University, Bursa, Turkey
| | - Emel Yılmaz
- Department of Clinical Microbiology and Infectious Diseases, Faculty of Medicine, Bursa Uludağ University, Bursa, Turkey
| | - Beyza Ener
- Department of Medical Microbiology, Faculty of Medicine, Bursa Uludağ University, Bursa, Turkey
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23
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Blass BE, Puri S, Sharma R, Day BM. Antifungal properties of (2S, 4R)-Ketoconazole sulfonamide analogs. FRONTIERS IN DRUG DISCOVERY 2022; 2:1000827. [PMID: 37214226 PMCID: PMC10198183 DOI: 10.3389/fddsv.2022.1000827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Invasive candidiasis remains a significant health concern, as it is associated with a high mortality risk. In addition, the risk of infection is significantly elevated in immunocompromised patients such as those with HIV, cancer, or those taking imcmunosuppressive drugs as a result of organ transplantation. The majority of these cases are caused by C. albicans, and C. glabrata is the second most common cause. These infections are typically treated using approved antifungal agents, but the rise of drug-resistant fungi is a serious concern. As part of our on-going effort to identify novel antifungal agents, we have studied the in vitro antifungal properties of a series of sulfonamide analogs of (2S, 4R)-Ketoconazole. Herein we report on the in vitro activity against the key fungal pathogens C. albicans, and C. glabrata.
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Affiliation(s)
- Benjamin E. Blass
- Department of Pharmaceutical Sciences, Temple University School of Pharmacy, Philadelphia, PA, United States
| | - Sumant Puri
- Oral Microbiome Research Laboratory, Kornberg School of Dentistry, Temple University, Philadelphia, PA, United Stated
| | - Rishabh Sharma
- Oral Microbiome Research Laboratory, Kornberg School of Dentistry, Temple University, Philadelphia, PA, United Stated
| | - Brian M. Day
- Department of Pharmaceutical Sciences, Temple University School of Pharmacy, Philadelphia, PA, United States
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24
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Salazar SB, Pinheiro MJF, Sotti-Novais D, Soares AR, Lopes MM, Ferreira T, Rodrigues V, Fernandes F, Mira NP. Disclosing azole resistance mechanisms in resistant Candida glabrata strains encoding wild-type or gain-of-function CgPDR1 alleles through comparative genomics and transcriptomics. G3 (BETHESDA, MD.) 2022; 12:jkac110. [PMID: 35532173 PMCID: PMC9258547 DOI: 10.1093/g3journal/jkac110] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 04/25/2022] [Indexed: 12/03/2022]
Abstract
The pathogenic yeast Candida glabrata is intrinsically resilient to azoles and rapidly acquires resistance to these antifungals, in vitro and in vivo. In most cases azole-resistant C. glabrata clinical strains encode hyperactive CgPdr1 variants, however, resistant strains encoding wild-type CgPDR1 alleles have also been isolated, although remaining to be disclosed the underlying resistance mechanism. In this study, we scrutinized the mechanisms underlying resistance to azoles of 8 resistant clinical C. glabrata strains, identified along the course of epidemiological surveys undertaken in Portugal. Seven of the strains were found to encode CgPdr1 gain-of-function variants (I392M, E555K, G558C, and I803T) with the substitutions I392M and I803T being herein characterized as hyper-activating mutations for the first time. While cells expressing the wild-type CgPDR1 allele required the mediator subunit Gal11A to enhance tolerance to fluconazole, this was dispensable for cells expressing the I803T variant indicating that the CgPdr1 interactome is shaped by different gain-of-function substitutions. Genomic and transcriptomic profiling of the sole azole-resistant C. glabrata isolate encoding a wild-type CgPDR1 allele (ISTB218) revealed that under fluconazole stress this strain over-expresses various genes described to provide protection against this antifungal, while also showing reduced expression of genes described to increase sensitivity to these drugs. The overall role in driving the azole-resistance phenotype of the ISTB218 C. glabrata isolate played by these changes in the transcriptome and genome of the ISTB218 isolate are discussed shedding light into mechanisms of resistance that go beyond the CgPdr1-signalling pathway and that may alone, or in combination, pave the way for the acquisition of resistance to azoles in vivo.
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Affiliation(s)
- Sara B Salazar
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico—Department of Bioengineering, Universidade de Lisboa, Lisboa 1049-001, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisboa 1049-001, Portugal
| | - Maria Joana F Pinheiro
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico—Department of Bioengineering, Universidade de Lisboa, Lisboa 1049-001, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisboa 1049-001, Portugal
| | - Danielle Sotti-Novais
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico—Department of Bioengineering, Universidade de Lisboa, Lisboa 1049-001, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisboa 1049-001, Portugal
| | - Ana R Soares
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, Aveiro 3810, Portugal
| | - Maria M Lopes
- Departamento de Microbiologia e Imunologia, Faculdade de Farmácia da Universidade de Lisboa, Lisboa 1649-003, Portugal
| | - Teresa Ferreira
- Laboratório de Microbiologia, Hospital Dona Estefânia (Centro Hospitalar Universitário Lisboa Central), Lisboa 1169-045, Portugal
| | - Vitória Rodrigues
- Seção de Microbiologia, Laboratório SYNLAB—Lisboa, Grupo SYNLAB Portugal, Lisboa 1070-061, Portugal
| | - Fábio Fernandes
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico—Department of Bioengineering, Universidade de Lisboa, Lisboa 1049-001, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisboa 1049-001, Portugal
| | - Nuno P Mira
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico—Department of Bioengineering, Universidade de Lisboa, Lisboa 1049-001, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisboa 1049-001, Portugal
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25
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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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26
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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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27
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Castanheira M, Deshpande LM, Davis AP, Carvalhaes CG, Pfaller MA. Azole Resistance in Candida glabrata Clinical Isolates from Global Surveillance is Associated with Efflux Overexpression. J Glob Antimicrob Resist 2022; 29:371-377. [DOI: 10.1016/j.jgar.2022.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 05/05/2022] [Accepted: 05/06/2022] [Indexed: 11/28/2022] Open
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28
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Augmenting Azoles with Drug Synergy to Expand the Antifungal Toolbox. Pharmaceuticals (Basel) 2022; 15:ph15040482. [PMID: 35455479 PMCID: PMC9027798 DOI: 10.3390/ph15040482] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 03/25/2022] [Accepted: 03/26/2022] [Indexed: 12/23/2022] Open
Abstract
Fungal infections impact the lives of at least 12 million people every year, killing over 1.5 million. Wide-spread use of fungicides and prophylactic antifungal therapy have driven resistance in many serious fungal pathogens, and there is an urgent need to expand the current antifungal arsenal. Recent research has focused on improving azoles, our most successful class of antifungals, by looking for synergistic interactions with secondary compounds. Synergists can co-operate with azoles by targeting steps in related pathways, or they may act on mechanisms related to resistance such as active efflux or on totally disparate pathways or processes. A variety of sources of potential synergists have been explored, including pre-existing antimicrobials, pharmaceuticals approved for other uses, bioactive natural compounds and phytochemicals, and novel synthetic compounds. Synergy can successfully widen the antifungal spectrum, decrease inhibitory dosages, reduce toxicity, and prevent the development of resistance. This review highlights the diversity of mechanisms that have been exploited for the purposes of azole synergy and demonstrates that synergy remains a promising approach for meeting the urgent need for novel antifungal strategies.
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29
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Gupta P, Poluri KM. Elucidating the Eradication Mechanism of Perillyl Alcohol against Candida glabrata Biofilms: Insights into the Synergistic Effect with Azole Drugs. ACS BIO & MED CHEM AU 2022; 2:60-72. [PMID: 37102177 PMCID: PMC10114769 DOI: 10.1021/acsbiomedchemau.1c00034] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Increased incidences of fungal infections and associated mortality have accelerated the need for effective and alternative therapeutics. Perillyl alcohol (PA) is a terpene produced by the hydroxylation of limonene via the mevalonate pathway. In pursuit of an alternative antifungal agent, we studied the effect of PA on the biofilm community of Candida glabrata and on different cellular pathways to decipher its mode of action. PA efficiently inhibited growth and eradicated biofilms by reducing carbohydrate and eDNA content in the extracellular matrix. PA reduced the activity of hydrolytic enzymes in the ECM of C. glabrata biofilm. The chemical profiling study has given insights into the overall mode of action of PA in C. glabrata and the marked involvement of the cell wall and membrane, ergosterol biosynthesis, oxidative stress, and DNA replication. The spectroscopic and RT-PCR studies suggested a strong interaction of PA with chitin, β-glucan, ergosterol, and efflux pump, thus indicating increased membrane fluidity in C. glabrata. Furthermore, the microscopic and flow cytometry analysis emphasized that PA facilitated the change in mitochondrial activity, increased Ca2+ influx via overexpression of voltage-gated Ca2+ channels, and enhanced cytochrome C release from mitochondria. In addition, PA interferes with DNA replication and thus hinders the cell cycle progression at the S-phase. All these studies together established that PA mitigates the C. glabrata biofilms by targeting multiple cellular pathways. Interestingly, PA also potentiated the efficacy of azole drugs, particularly miconazole, against C. glabrata and its clinical isolates. Conclusively, the study demonstrated the use of PA as an effective antifungal agent alone or in combination with FDA-approved conventional drugs for fungal biofilm eradication.
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Affiliation(s)
- Payal Gupta
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India
| | - Krishna Mohan Poluri
- Department of Biosciences and Bioengineering, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India
- Centre for Nanotechnology, Indian Institute of Technology Roorkee, Roorkee 247667, Uttarakhand, India
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30
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Gaspar-Cordeiro A, Afonso G, Amaral C, da Silva SM, Pimentel C. Zap1 is required for Candida glabrata response to fluconazole. FEMS Yeast Res 2022; 22:6510815. [PMID: 35040997 DOI: 10.1093/femsyr/foab068] [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: 08/18/2021] [Accepted: 01/13/2022] [Indexed: 11/13/2022] Open
Abstract
The increasing prevalence of fluconazole-resistant clinical isolates of Candida spp. strongly hinders the widespread use of the drug. To tackle this problem, great efforts have been made to fully understand the fungal response to fluconazole. In this work, we show that the role of Zap1 in Candida glabrata goes beyond regulating yeast adaptation to zinc deficiency. In line with our previous observation that deletion of ZAP1 makes yeast cells more sensitive to fluconazole, we found that the mutant CgΔzap1 accumulates higher levels of the drug, which correlates well with its lower levels of ergosterol. Surprisingly, Zap1 is a negative regulator of the drug efflux transporter gene CDR1 and of its regulator, PDR1. The apparent paradox of drug accumulation in cells where genes encoding transporters relevant for drug extrusion are being overexpressed led us to postulate that their activity could be impaired. In agreement, Zap1-depleted cells present, in addition to decreased ergosterol levels, an altered composition of membrane phospholipids, which together should impact membrane function and impair the detoxification of fluconazole. Overall, our study brings to light Zap1 as an important hub in Candida glabrata response to fluconazole.
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Affiliation(s)
- A Gaspar-Cordeiro
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. República, 2780-157 Oeiras, Portugal
| | - G Afonso
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. República, 2780-157 Oeiras, Portugal
| | - C Amaral
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. República, 2780-157 Oeiras, Portugal
| | - S M da Silva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. República, 2780-157 Oeiras, Portugal
| | - C Pimentel
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. República, 2780-157 Oeiras, Portugal
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31
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Azole-resistant alleles of
ERG11
in
Candida glabrata
trigger activation of the Pdr1 and Upc2A transcription factors. Antimicrob Agents Chemother 2022; 66:e0209821. [DOI: 10.1128/aac.02098-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Azoles, the most commonly used antifungal drugs, specifically inhibit the fungal lanosterol α-14 demethylase enzyme, which is referred to as Erg11. Inhibition of Erg11 ultimately leads to a reduction in ergosterol production, an essential fungal membrane sterol. Many
Candida
species, such as
Candida albicans
, develop mutations in this enzyme which reduces the azole binding affinity and results in increased resistance.
Candida glabrata
is also a pathogenic yeast that has low intrinsic susceptibility to azole drugs and easily develops elevated resistance. In
C. glabrata
, these azole resistant mutations typically cause hyperactivity of the Pdr1 transcription factor and rarely lie within the
ERG11
gene. Here, we generated
C. glabrata
ERG11
mutations that were analogous to azole resistance alleles from
C. albicans
ERG11
. Three different Erg11 forms (Y141H, S410F, and the corresponding double mutant (DM)) conferred azole resistance in
C. glabrata
with the DM Erg11 form causing the strongest phenotype. The DM Erg11 also induced cross-resistance to amphotericin B and caspofungin. Resistance caused by the DM allele of
ERG11
imposed a fitness cost that was not observed with hyperactive
PDR1
alleles. Crucially, the presence of the DM
ERG11
allele was sufficient to activate the Pdr1 transcription factor in the absence of azole drugs. Our data indicate that azole resistance linked to changes in
ERG11
activity can involve cellular effects beyond an alteration in this key azole target enzyme. Understanding the physiology linking ergosterol biosynthesis with Pdr1-mediated regulation of azole resistance is crucial for ensuring the continued efficacy of azole drugs against
C. glabrata
.
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32
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Characterization of the Candida glabrata Transcription Factor CgMar1: Role in Azole Susceptibility. J Fungi (Basel) 2022; 8:jof8010061. [PMID: 35050001 PMCID: PMC8779156 DOI: 10.3390/jof8010061] [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: 12/21/2021] [Revised: 01/03/2022] [Accepted: 01/05/2022] [Indexed: 11/18/2022] Open
Abstract
The prevalence of antifungal resistance in Candida glabrata, especially against azole drugs, results in difficult-to-treat and potentially life-threatening infections. Understanding the molecular basis of azole resistance in C. glabrata is crucial to designing more suitable therapeutic strategies. In this study, the role of the transcription factor encoded by ORF CAGL0B03421g, here denominated as CgMar1 (Multiple Azole Resistance 1), in azole susceptibility was explored. Using RNA-sequencing, CgMar1 was found to regulate 337 genes under fluconazole stress, including several related to lipid biosynthesis pathways. In this context, CgMar1 and its target CgRSB1, encoding a predicted sphingoid long-chain base efflux transporter, were found to contribute to plasma membrane sphingolipid incorporation and membrane permeability, decreasing fluconazole accumulation. CgMar1 was found to associate with the promoter of CgRSB1, which contains two instances of the CCCCTCC consensus, found to be required for CgRSB1 activation during fluconazole stress. Altogether, a regulatory pathway modulating azole susceptibility in C. glabrata is proposed, resulting from what appears to be a neofunctionalization of a Hap1-like transcription factor.
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33
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Thomas A, Bankar N, Nagore D, Kothapalli L, Chitlange S. Herbal Oils for Treatment of Chronic and Diabetic Wounds: A Systematic Review. Curr Diabetes Rev 2022; 18:e220321192406. [PMID: 34225631 DOI: 10.2174/1573399817666210322151700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 11/29/2020] [Accepted: 02/13/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND In the present scenario, diabetes is a growing health challenge, and its occurrence is growing across the globe. Diabetes, with its complications like diabetic wounds, vasculopathy, neuropathy, wound infections, and oxidative stress, is a serious cause of mortality worldwide. INTRODUCTION Among the various complications, treatment of diabetic foot and ulcers is one of the major concerns in patients who are suffering from diabetes. The causative factors for this condition include increased oxidative stress, high blood glucose levels, vascular insufficiency, and microbial infections, and many a time, if left untreated, it may even lead to amputations of the lower extremities. The present therapy for the treatment of diabetic wounds mainly involves the use of synthetic moieties and other biotechnology-derived biomolecules, including growth factors. Few plant products are also useful in the treatment of wounds. METHODS Essential oils derived from various herbs are reported to possess significant wound healing potential and promote blood clotting, help to fight infections, and accelerate the wound healing process. Hence, the present review is a systematic analysis of all the available data on the use of the natural oils with their biological source, active phytochemical constituents present, and the probable mechanism of action for the treatment of chronic and diabetic wounds in suitable animal models. A methodical collection of data was performed, and information was searched up to April 2020 in entirety. Key phrases used for the data search include the pathophysiology of wounds, diabetic foot wound and its complications, natural oils for chronic and diabetic wound treatment. RESULTS This review summarizes the natural oils which are reported in the literature to be beneficial in the treatment of chronic wounds, while some oils have been specifically also studied against wounds in diabetic rats. Essential oils are said to interact with the body pharmacologically, physiologically and psychologically and help in rapid wound healing. However, the majority of the literature studies have demonstrated wound healing activity only in animal models (preclinical data), and further clinical studies are necessary. CONCLUSION This review provides a platform for further studies on the effective utilization of natural oils in the treatment of chronic and diabetic wounds, especially if oils are to receive credibility in the management of chronic wounds.
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Affiliation(s)
- Asha Thomas
- Department of Pharmaceutical Chemistry, Dr. D. Y. Patil Institute of Pharmaceutical Sciences and Research, Pimpri, Pune, MS, India
| | - Nilam Bankar
- Department of Pharmaceutical Chemistry, Dr. D. Y. Patil Institute of Pharmaceutical Sciences and Research, Pimpri, Pune, MS, India
| | - Dheeraj Nagore
- Department of Pharmaceutical Chemistry, Dr. D. Y. Patil Institute of Pharmaceutical Sciences and Research, Pimpri, Pune, MS, India
| | - Lata Kothapalli
- Department of Pharmaceutical Chemistry, Dr. D. Y. Patil Institute of Pharmaceutical Sciences and Research, Pimpri, Pune, MS, India
| | - Sohan Chitlange
- Department of Pharmaceutical Chemistry, Dr. D. Y. Patil Institute of Pharmaceutical Sciences and Research, Pimpri, Pune, MS, India
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El-Ganiny AM, Kamel HA, Yossef NE, Mansour B, El-Baz AM. Repurposing pantoprazole and haloperidol as efflux pump inhibitors in azole resistant clinical Candida albicans and non-albicans isolates. Saudi Pharm J 2022; 30:245-255. [PMID: 35498219 PMCID: PMC9051972 DOI: 10.1016/j.jsps.2022.01.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 01/12/2022] [Indexed: 12/17/2022] Open
Abstract
Candida species have a major role in nosocomial infections leading to high morbidity and mortality. Increased resistance to various antifungals, especially azoles is a significant problem. One of the main mechanisms for azole resistance is the up-regulation of efflux pump genes including CDR1 and MDR1. In the current study, clinical Candida isolates were identified to the species level and the antifungal susceptibility (AFS) of different Candida species was determined by disk diffusion method. Furthermore, the main mechanisms of azole resistance were investigated. Finally, haloperidol and pantoprazole were tested for their potential synergistic effect against fluconazole-resistant isolates. One hundred and twenty-two Candida clinical isolates were used in this study. 70 isolates were Candida albicans (57.4%), the non-albicans Candida species include: C. krusei (20.5%), C. tropicalis (6.6%), C. parapsilosis (5.7%), C. dubliniensis (4.9%) and C. glabrata (4.9%). The AFS testing showed that resistance to fluconazole and voriconazole were 13.1% (n = 16) and 9.8% (n = 12), respectively. Among the 16 resistant isolates, eight isolates (50%) were strong biofilm producers, seven (43.8 %) formed intermediate biofilm and one had no biofilm. All resistant strains overexpressed efflux pumps. Using RT-PCR, the efflux genes CDR1, MDR1 and ABC2 were over-expressed in azole resistant isolates. Haloperidol-fluconazole and pantoprazole-fluconazole combinations reduced the MIC of fluconazole in resistant isolates. The current study showed an increase in azole resistance of Candida species. The majority of resistant isolates form biofilm, and overexpress efflux pumps. Pantoprazole and Haloperidol showed a noteworthy effect as efflux pump inhibitors which oppose the fluconazole resistance in different Candida species.
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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: 1] [Impact Index Per Article: 0.3] [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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Recent Advances in Photodynamic Therapy against Fungal Keratitis. Pharmaceutics 2021; 13:pharmaceutics13122011. [PMID: 34959293 PMCID: PMC8709008 DOI: 10.3390/pharmaceutics13122011] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 11/14/2021] [Accepted: 11/20/2021] [Indexed: 01/08/2023] Open
Abstract
Fungal keratitis is a serious clinical infection on the cornea caused by fungi and is one of the leading causes of blindness in Asian countries. The treatment options are currently limited to a few antifungal agents. With the increasing incidence of drug-resistant infections, many patients fail to respond to antibiotics. Riboflavin-mediated corneal crosslinking (similar to photodynamic therapy (PDT)) for corneal ectasia was approved in the US in the early 2000s. Current evidence suggests that PDT could have the potential to inhibit fungal biofilm formation and overcome drug resistance by using riboflavin and rose bengal as photosensitizers. However, only a few clinical trials have been initiated in anti-fungal keratitis PDT treatment. Moreover, the removal of the corneal epithelium and repeated application of riboflavin and rose bengal are required to improve drug penetration before and during PDT. Thus, an improvement in trans-corneal drug delivery is mandatory for a successful and efficient treatment. In this article, we review the studies published to date using PDT against fungal keratitis and aim to enhance the understanding and awareness of this research area. The potential of modifying photosensitizers using nanotechnology to improve the efficacy of PDT on fungal keratitis is also briefly reviewed.
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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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M El-Ganiny A, E Yossef N, A Kamel H. Prevalence and antifungal drug resistance of nosocomial Candida species isolated from two university hospitals in Egypt. Curr Med Mycol 2021; 7:31-37. [PMID: 34553095 PMCID: PMC8443875 DOI: 10.18502/cmm.7.1.6181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 02/17/2021] [Accepted: 04/07/2021] [Indexed: 11/24/2022] Open
Abstract
Background and Purpose: There is a significant rise in morbidity and mortality of infections caused by Candida. Candida spp. infections are currently ranked fourth among nosocomial infections which are difficult
to diagnose and refractory to therapy. Given the differences in susceptibility among various spp., identification of Candida spp. is an important step that leads to the selection of a suitable antifungal. Materials and Methods: A prevalence study was conducted on 122 Candida isolates. The Candida spp. were identified using Chromogenic agar and polymerase chain reaction (PCR).
The antifungal susceptibility (AFS) of Candida spp. to amphotericin B, fluconazole, voriconazole, and caspofungin was determined by the disc diffusion method. Results: In total, 122 Candida clinical isolates were investigated in this study. Candida albicans with 57.4% (70 isolates) had the highest prevalence rate,
while 52 isolates (42.6%) were non-albicansCandida species (NAC). The NAC include Candida krusei (20.4%), Candida tropicalis (6.5%), Candida parapsilolsis (5.7%),
Candida dubliniensis (4.9%), and Candida glabrata (4.9%). The AFS showed that the resistance rates of Candida spp. to fluconazole and voriconazole were 13.1% (16 isolates)
and 9.8% (12 isolates), respectively. Moreover, only five isolates (4.1%) were resistant to caspofungin. Furthermore, there was no resistance against amphotericin B. The spp.
that showed the highest resistance were C. glabrata and C. tropicalis, while the lowest resistance was observed in C. albicans and C. dubliniensis. Conclusion: In conclusion, rapid identification of clinical Candida isolates and standard AFS are essential procedures for controlling the rise of resistant NAC spp. in clinical settings.
Usage of fluconazole should be restricted, especially in patients with recurrent Candida infections.
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Affiliation(s)
- Amira M El-Ganiny
- Microbiology and Immunology Department, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Nehal E Yossef
- Microbiology and Immunology Department, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Hend A Kamel
- Microbiology and Immunology Department, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt.,Microbiology Department, Faculty of Pharmacy and Pharmaceutical Industries, Sinai University, Kantara, Egypt
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Abstract
Anti-fungal therapies remain sub-optimal, and resistant pathogens are increasing. New therapies are desperately needed, especially options that are less toxic than most of the currently available selection. In this review, I will discuss anti-fungal therapies that are in at least phase I human trials. These include VT-1161 and VT-1598, modified azoles with a tetrazole metal-binding group; the echinocandin rezafugin; the novel β-1,3-d-glucan synthase inhibitor ibrexafungerp; fosmanogepix, a novel anti-fungal targeting Gwt1; the arylamidine T-2307; the dihydroorotate inhibitor olorofim; and the cyclic hexapeptide ASP2397. The available data including spectrum of activity, toxicity and stage of clinical development will be discussed for each of these so clinicians are aware of promising anti-fungal agents with a strong likelihood of clinical availability in the next 5–7 years.
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Affiliation(s)
- Grant Waterer
- University of Western Australia, Royal Perth Hospital, Level 3 Executive Corridor, Wellington St, Perth, 6000, Australia.
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Abstract
The breadth of fungi causing human disease and the spectrum of clinical presentations associated with these infections has widened. Epidemiologic trends display dramatic shifts with expanding geographic ranges, identification of new at-risk groups, increasing prevalence of resistant infections, and emergence of novel multidrug-resistant pathogenic fungi. Certain fungi have been transmitted between patients in clinical settings. Major health events not typically associated with mycoses resulted in larger proportions of the population susceptible to secondary fungal infections. Many health care-related, environmental, and socioeconomic factors have influenced these epidemiologic shifts. This review summarizes updates to clinically significant fungal pathogens in North America.
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Affiliation(s)
- Emma E Seagle
- ASRT, Inc, 4158 Onslow Pl, Smyrna, GA 30080, USA; Mycotic Diseases Branch, Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road Northeast, Atlanta, GA 30329-4018, USA
| | - Samantha L Williams
- ASRT, Inc, 4158 Onslow Pl, Smyrna, GA 30080, USA; Mycotic Diseases Branch, Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road Northeast, Atlanta, GA 30329-4018, USA
| | - Tom M Chiller
- Mycotic Diseases Branch, Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, 1600 Clifton Road Northeast, Atlanta, GA 30329-4018, USA.
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Abstract
Pathogenic fungi have several mechanisms of resistance to antifungal drugs, driven by the genetic plasticity and versatility of their homeostatic responses to stressful environmental cues. We critically review the molecular mechanisms of resistance and cellular adaptations of pathogenic fungi in response to antifungals and discuss the factors contributing to such resistance. We offer suggestions for the translational and clinical research agenda of this rapidly evolving and medically important field. A better understanding of antifungal resistance should assist in developing better detection tools and inform optimal strategies for preventing and treating refractory mycoses in the future.
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Affiliation(s)
- Ronen Ben-Ami
- Infectious Diseases Department, Sackler School of Medicine, Tel Aviv University, Tel Aviv Sourasky Medical Center, 6 Weizmann, Tel Aviv 64239, Israel
| | - Dimitrios P Kontoyiannis
- Infectious Diseases, University of Texas M D Anderson Cancer Center, 1515 Holcombe, Houston, TX 77030, USA.
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Two Functionally Redundant FK506-Binding Proteins Regulate Multidrug Resistance Gene Expression and Govern Azole Antifungal Resistance. Antimicrob Agents Chemother 2021; 65:AAC.02415-20. [PMID: 33722894 DOI: 10.1128/aac.02415-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 03/06/2021] [Indexed: 12/14/2022] Open
Abstract
Increasing resistance to antifungal therapy is an impediment to the effective treatment of fungal infections. Candida glabrata is an opportunistic human fungal pathogen that is inherently less susceptible to cost-effective azole antifungals. Gain-of-function mutations in the Zn-finger pleiotropic drug resistance transcriptional activator-encoding gene CgPDR1 are the most prevalent causes of azole resistance in clinical settings. CgPDR1 is also transcriptionally activated upon azole exposure; however, factors governing CgPDR1 gene expression are not yet fully understood. Here, we have uncovered a novel role for two FK506-binding proteins, CgFpr3 and CgFpr4, in the regulation of the CgPDR1 regulon. We show that CgFpr3 and CgFpr4 possess a peptidyl-prolyl isomerase domain and act redundantly to control CgPDR1 expression, as a Cgfpr3Δ4Δ mutant displayed elevated expression of the CgPDR1 gene along with overexpression of its target genes, CgCDR1, CgCDR2, and CgSNQ2, which code for ATP-binding cassette multidrug transporters. Furthermore, CgFpr3 and CgFpr4 are required for the maintenance of histone H3 and H4 protein levels, and fluconazole exposure leads to elevated H3 and H4 protein levels. Consistent with the role of histone proteins in azole resistance, disruption of genes coding for the histone demethylase CgRph1 and the histone H3K36-specific methyltransferase CgSet2 leads to increased and decreased susceptibility to fluconazole, respectively, with the Cgrph1Δ mutant displaying significantly lower basal expression levels of the CgPDR1 and CgCDR1 genes. These data underscore a hitherto unknown role of histone methylation in modulating the most common azole antifungal resistance mechanism. Altogether, our findings establish a link between CgFpr-mediated histone homeostasis and CgPDR1 gene expression and implicate CgFpr in the virulence of C. glabrata.
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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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Raj S, Vinod V, Jayakumar J, Suresh P, Kumar A, Biswas R. Antifungal activity of Syzygium samarangense leaf extracts against Candida. Lett Appl Microbiol 2021; 73:31-38. [PMID: 33735468 DOI: 10.1111/lam.13471] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 03/08/2021] [Accepted: 03/09/2021] [Indexed: 11/26/2022]
Abstract
Candida species are opportunistic human fungal pathogens that cause acute and chronic infections against which only few antifungal agents are available. Here we have elucidated the antifungal effect of Syzygium samarangense leaf extracts (SSLE). Antifungal activity of SSLE was studied against Candida albicans, C. krusei, C. parapsilosis, C. glabrata, C. auris and C. tropicalis. Following experiments were performed: minimum fungicidal concentration (MFC) determination, agar well disc diffusion assays, fungal morphology analysis using scanning electron microscope (SEM), ex vivo fungal survival assays on porcine tongue and skin and in vivo fungal survival assays using Drosophila melanogaster fly model. Results demonstrated MFC of SSLE ranges between 100 and 125 mg ml-1 . SEM images showed cell wall degradation of C. albicans when treated with SSLE. Around 75% decrease in C. albicans viability was observed when infected porcine tongue and skin were treated using SSLE. The C. albicans infected D. melanogaster when fed with SSLE showed significant decrease (around 80%) of fungal count than the infected control. Furthermore, agar plate disc diffusion assays demonstrated that the antifungal activity of SSLE could be due to chalcone, which is one of the active constituents in SSLE. Our study demonstrated that SSLE could be used for the topical treatment of Candida infections.
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Affiliation(s)
- S Raj
- Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Kochi, Kerala, India
| | - V Vinod
- Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Kochi, Kerala, India
| | - J Jayakumar
- Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Kochi, Kerala, India
| | - P Suresh
- Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Kochi, Kerala, India
| | - A Kumar
- Department of Microbiology, Amrita Institute of Medical Sciences, Amrita Vishwa Vidyapeetham, Kochi, Kerala, India
| | - R Biswas
- Centre for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Kochi, Kerala, India
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Kumari S, Kumar M, Gaur NA, Prasad R. Multiple roles of ABC transporters in yeast. Fungal Genet Biol 2021; 150:103550. [PMID: 33675986 DOI: 10.1016/j.fgb.2021.103550] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 01/29/2021] [Accepted: 02/25/2021] [Indexed: 12/20/2022]
Abstract
The ATP binding cassette (ABC) transporters, first discovered as high-affinity nutrient importers in bacteria, rose to prominence when their ability to confer multidrug resistance (MDR) to cancer cells was realized. The most characterized human permeability glycoprotein (P-gp) is a dominant exporter of anti-cancer drugs and its overexpression is directly linked to MDR. The overexpression of drug efflux pumps belonging to the ABC superfamily is also a frequent cause of resistance to antifungals. Fungi has a battery of ABC proteins, but in variable numbers and at different subcellular locations. These proteins perform many critical functions, from serving as gatekeepers for xenobiotic cleansing to translocating various structurally unrelated cargoes, including lipids, fatty acids, ions, peptides, sterols, metabolites and toxins. Their emerging additional roles in cellular physiology and virulence call for attention to analyze and re-examine their divergent functions in yeast. In brief, this review traces the history of ABC transporters in yeast and discusses their typical physiological functions that go beyond their well-known role as antifungal drug efflux pumps.
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Affiliation(s)
- Sonam Kumari
- Yeast Biofuel Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Mohit Kumar
- Yeast Biofuel Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India; Amity Institute of Integrative Science and Health, Amity Institute of Biotechnology, Amity University Gurgaon, 122413 Haryana, India
| | - Naseem A Gaur
- Yeast Biofuel Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India.
| | - Rajendra Prasad
- Amity Institute of Integrative Science and Health, Amity Institute of Biotechnology, Amity University Gurgaon, 122413 Haryana, India.
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Comparison of Two Commercially Available qPCR Kits for the Detection of Candida auris. J Fungi (Basel) 2021; 7:jof7020154. [PMID: 33671676 PMCID: PMC7926799 DOI: 10.3390/jof7020154] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Revised: 02/07/2021] [Accepted: 02/18/2021] [Indexed: 12/22/2022] Open
Abstract
Candida auris is an emerging pathogen with resistance to many commonly used antifungal agents. Infections with C. auris require rapid and reliable detection methods to initiate successful medical treatment and contain hospital outbreaks. Conventional identification methods are prone to errors and can lead to misidentifications. PCR-based assays, in turn, can provide reliable results with low turnaround times. However, only limited data are available on the performance of commercially available assays for C. auris detection. In the present study, the two commercially available PCR assays AurisID (OLM, Newcastle Upon Tyne, UK) and Fungiplex Candida Auris RUO Real-Time PCR (Bruker, Bremen, Germany) were challenged with 29 C. auris isolates from all five clades and eight other Candida species as controls. AurisID reliably detected C. auris with a limit of detection (LoD) of 1 genome copies/reaction. However, false positive results were obtained with high DNA amounts of the closely related species C. haemulonii, C. duobushaemulonii and C. pseudohaemulonii. The Fungiplex Candida Auris RUO Real-Time PCR kit detected C. auris with an LoD of 9 copies/reaction. No false positive results were obtained with this assay. In addition, C. auris could also be detected in human blood samples spiked with pure fungal cultures by both kits. In summary, both kits could detect C. auris-DNA at low DNA concentrations but differed slightly in their limits of detection and specificity.
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Buechel ER, Pinkett HW. Transcription factors and ABC transporters: from pleiotropic drug resistance to cellular signaling in yeast. FEBS Lett 2020; 594:3943-3964. [PMID: 33089887 DOI: 10.1002/1873-3468.13964] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/07/2020] [Accepted: 10/15/2020] [Indexed: 12/24/2022]
Abstract
Budding yeast Saccharomyces cerevisiae survives in microenvironments utilizing networks of regulators and ATP-binding cassette (ABC) transporters to circumvent toxins and a variety of drugs. Our understanding of transcriptional regulation of ABC transporters in yeast is mainly derived from the study of multidrug resistance protein networks. Over the past two decades, this research has not only expanded the role of transcriptional regulators in pleiotropic drug resistance (PDR) but evolved to include the role that regulators play in cellular signaling and environmental adaptation. Inspection of the gene networks of the transcriptional regulators and characterization of the ABC transporters has clarified that they also contribute to environmental adaptation by controlling plasma membrane composition, toxic-metal sequestration, and oxidative stress adaptation. Additionally, ABC transporters and their regulators appear to be involved in cellular signaling for adaptation of S. cerevisiae populations to nutrient availability. In this review, we summarize the current understanding of the S. cerevisiae transcriptional regulatory networks and highlight recent work in other notable fungal organisms, underlining the expansion of the study of these gene networks across the kingdom fungi.
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Affiliation(s)
- Evan R Buechel
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
| | - Heather W Pinkett
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, USA
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Bazana LCG, Carvalho ÂR, Silveira GP, S. de Oliveira LF, Teixeira ML, Lopes W, Vainstein MH, Barbosa FAR, Russo TVC, Sá MM, Canto RFS, Fuentefria AM. Allylic Selenocyanates as Antifungal Agents Against Pathogenic
Candida
Species. ChemistrySelect 2020. [DOI: 10.1002/slct.202002170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Luana C. G. Bazana
- Laboratório de Pesquisa em Micologia Aplicada Faculdade de Farmácia-Anexo 2, UFRGS Rua São Luis 154 90470440 Porto Alegre Brazil
| | - Ânderson R. Carvalho
- Laboratório de Pesquisa em Micologia Aplicada Faculdade de Farmácia-Anexo 2, UFRGS Rua São Luis 154 90470440 Porto Alegre Brazil
| | - Gustavo P. Silveira
- Departamento de Química Orgânica Instituto de Química, UFRGS Avenida Bento Gonçalves 9500 90650-001 Porto Alegre Brazil
| | | | - Mário L. Teixeira
- Laboratório de Pesquisa em Toxicologia e Farmacologia IFC SC 283 -Km 8 89700-000 Concordia Brazil
| | - William Lopes
- Departamento de Biologia Molecular e Biotecnologia UFRGS Avenida Bento Gonçalves 9500 91501-970 Porto Alegre Brazil
| | - Marilene H. Vainstein
- Departamento de Biologia Molecular e Biotecnologia UFRGS Avenida Bento Gonçalves 9500 91501-970 Porto Alegre Brazil
| | - Flavio A. R. Barbosa
- Departamento de Química, UFSC Rua Engenheiro Agronômico Andrei Cristian Ferreira 88040-900 Florianópolis Brazil
| | - Theo V. C. Russo
- Departamento de Química, UFSC Rua Engenheiro Agronômico Andrei Cristian Ferreira 88040-900 Florianópolis Brazil
| | - Marcus M. Sá
- Departamento de Química, UFSC Rua Engenheiro Agronômico Andrei Cristian Ferreira 88040-900 Florianópolis Brazil
| | - Rômulo F. S. Canto
- Departamento de Farmacociências UFCSPA Rua Sarmento Leite 287 90050-170 Porto Alegre Brazil
| | - Alexandre M. Fuentefria
- Laboratório de Pesquisa em Micologia Aplicada Faculdade de Farmácia-Anexo 2, UFRGS Rua São Luis 154 90470440 Porto Alegre Brazil
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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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Simonicova L, Moye-Rowley WS. Functional information from clinically-derived drug resistant forms of the Candida glabrata Pdr1 transcription factor. PLoS Genet 2020; 16:e1009005. [PMID: 32841236 PMCID: PMC7473514 DOI: 10.1371/journal.pgen.1009005] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 09/04/2020] [Accepted: 07/22/2020] [Indexed: 02/02/2023] Open
Abstract
Azole drugs are the most frequently used antifungal agents. The pathogenic yeast Candida glabrata acquires resistance to azole drugs via single amino acid substitution mutations eliciting a gain-of-function (GOF) hyperactive phenotype in the Pdr1 transcription factor. These GOF mutants constitutively drive high transcription of target genes such as the ATP-binding cassette transporter-encoding CDR1 locus. Previous characterization of Pdr1 has demonstrated that this factor is negatively controlled by the action of a central regulatory domain (CRD) of ~700 amino acids, in which GOF mutations are often found. Our earlier experiments demonstrated that a Pdr1 derivative in which the CRD was deleted gave rise to a transcriptional regulator that could not be maintained as the sole copy of PDR1 in the cell owing to its toxically high activity. Using a set of GOF PDR1 alleles from azole-resistant clinical isolates, we have analyzed the mechanisms acting to repress Pdr1 transcriptional activity. Our data support the view that Pdr1-dependent transactivation is mediated by a complex network of transcriptional coactivators interacting with the extreme C-terminal part of Pdr1. These coactivators include but are not limited to the Mediator component Med15A. Activity of this C-terminal domain is controlled by the CRD and requires multiple regions across the C-terminus for normal function. We also provide genetic evidence for an element within the transactivation domain that mediates the interaction of Pdr1 with coactivators on one hand while restricting Pdr1 activity on the other hand. These data indicate that GOF mutations in PDR1 block nonidentical negative inputs that would otherwise restrain Pdr1 transcriptional activation. The strong C-terminal transactivation domain of Pdr1 uses multiple different protein regions to recruit coactivators. Resistance to antibiotics is a major threat to the continued use of these lifesaving chemotherapeutic drugs. This problem is especially acute in the case of antifungal drugs as only 3 classes of these compounds exist. The pathogenic yeast Candida glabrata acquires resistance to the azole class of antifungal drugs by developing hyperactive alleles of the PDR1 gene, encoding a major inducer of azole resistance. We provide evidence that these hyperactive mutant proteins identify different negative inputs that would otherwise repress the transcriptional activity of Pdr1. Mutational analysis of the extreme C-terminus of Pdr1 indicated that this region exhibited multiple different interactions with coactivator proteins required for normal transcriptional activation of target gene expression. The data reported here shed light on the complicated nature of regulation of Pdr1 activity and identify domains in this protein that are bifunctional in their role to ensure normal factor activity. A detailed understanding of the molecular control of Pdr1 will allow strategies to be devised to reverse the azole resistance triggered by mutant forms of this protein.
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Affiliation(s)
- Lucia Simonicova
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA, United States of America
| | - W. Scott Moye-Rowley
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA, United States of America
- * E-mail:
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