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Kaden T, Alonso-Roman R, Akbarimoghaddam P, Mosig AS, Graf K, Raasch M, Hoffmann B, Figge MT, Hube B, Gresnigt MS. Modeling of intravenous caspofungin administration using an intestine-on-chip reveals altered Candida albicans microcolonies and pathogenicity. Biomaterials 2024; 307:122525. [PMID: 38489910 DOI: 10.1016/j.biomaterials.2024.122525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 02/21/2024] [Accepted: 03/06/2024] [Indexed: 03/17/2024]
Abstract
Candida albicans is a commensal yeast of the human intestinal microbiota that, under predisposing conditions, can become pathogenic and cause life-threatening systemic infections (candidiasis). Fungal-host interactions during candidiasis are commonly studied using conventional 2D in vitro models, which have provided critical insights into the pathogenicity. However, microphysiological models with a higher biological complexity may be more suitable to mimic in vivo-like infection processes and antifungal drug efficacy. Therefore, a 3D intestine-on-chip model was used to investigate fungal-host interactions during the onset of invasive candidiasis and evaluate antifungal treatment under clinically relevant conditions. By combining microbiological and image-based analyses we quantified infection processes such as invasiveness and fungal translocation across the epithelial barrier. Additionally, we obtained novel insights into fungal microcolony morphology and association with the tissue. Our results demonstrate that C. albicans microcolonies induce injury to the epithelial tissue by disrupting apical cell-cell contacts and causing inflammation. Caspofungin treatment effectively reduced the fungal biomass and induced substantial alterations in microcolony morphology during infection with a wild-type strain. However, caspofungin showed limited effects after infection with an echinocandin-resistant clinical isolate. Collectively, this organ-on-chip model can be leveraged for in-depth characterization of pathogen-host interactions and alterations due to antimicrobial treatment.
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Affiliation(s)
- Tim Kaden
- Dynamic42 GmbH, Jena, Germany; Institute of Biochemistry II, Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany
| | - Raquel Alonso-Roman
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute, Jena, Germany; Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, Jena, Germany
| | - Parastoo Akbarimoghaddam
- Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, Jena, Germany; Applied Systems Biology, HKI-Center for Systems Biology of Infection, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute, Jena, Germany; Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany
| | - Alexander S Mosig
- Institute of Biochemistry II, Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany; Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, Jena, Germany
| | | | | | - Bianca Hoffmann
- Applied Systems Biology, HKI-Center for Systems Biology of Infection, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute, Jena, Germany
| | - Marc T Figge
- Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, Jena, Germany; Applied Systems Biology, HKI-Center for Systems Biology of Infection, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute, Jena, Germany; Institute of Microbiology, Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany.
| | - Bernhard Hube
- Department of Microbial Pathogenicity Mechanisms, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute, Jena, Germany; Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, Jena, Germany; Institute of Microbiology, Faculty of Biological Sciences, Friedrich Schiller University, Jena, Germany.
| | - Mark S Gresnigt
- Cluster of Excellence Balance of the Microverse, Friedrich Schiller University Jena, Jena, Germany; Junior Research Group Adaptive Pathogenicity Strategies, Leibniz Institute for Natural Product Research and Infection Biology - Hans-Knöll-Institute, Jena, Germany.
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Lefranc M, Accoceberry I, Fitton-Ouhabi V, Biteau N, Noël T. Rapamycin and caspofungin show synergistic antifungal effects in caspofungin-susceptible and caspofungin-resistant Candida strains in vitro. J Antimicrob Chemother 2024; 79:151-156. [PMID: 37991226 DOI: 10.1093/jac/dkad359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 11/07/2023] [Indexed: 11/23/2023] Open
Abstract
OBJECTIVES Caspofungin is an echinocandin antifungal agent that inhibits synthesis of glucan required for the fungal cell wall. Resistance is mediated by mutation of Fks1 glucan synthase, among which S645P is the most common resistance-associated polymorphism. Rapamycin is a macrolide that inhibits the mechanistic target of rapamycin (mTOR) protein kinase activity. This study investigated the interaction between rapamycin and caspofungin in inhibiting the growth of WT Candida albicans and Fks1 S645P mutant clinical isolate, and WT Candida lusitaniae and genetically engineered isogenic strain with Fks1 S645P mutation at equivalent position. METHODS Interactions between caspofungin and rapamycin were evaluated using the microdilution chequerboard method in liquid medium. The results were analysed using the Loewe additivity model (FIC index, FICI) and the Bliss independence model (response surface, RS, analysis). RESULTS Synergy between rapamycin and caspofungin was shown for C. albicans and C. lusitaniae strains by RS analysis of the chequerboard tests. Synergy was observed in strains susceptible and resistant to caspofungin. Weak subinhibitory concentrations of rapamycin were sufficient to restore caspofungin susceptibility. CONCLUSIONS We report here, for the first time, synergy between caspofungin and rapamycin in Candida species. Synergy was shown for strains susceptible and resistant to caspofungin. This study highlights the possible implication of the TOR pathway in sensing antifungal-mediated cell wall stress and in modulating the cellular response to echinocandins in Candida yeasts.
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Affiliation(s)
- Maxime Lefranc
- University Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33000 Bordeaux, France
- University Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, CHU Bordeaux, 33000 Bordeaux, France
| | - Isabelle Accoceberry
- University Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33000 Bordeaux, France
- University Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, CHU Bordeaux, 33000 Bordeaux, France
| | - Valérie Fitton-Ouhabi
- University Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33000 Bordeaux, France
| | - Nicolas Biteau
- University Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33000 Bordeaux, France
| | - Thierry Noël
- University Bordeaux, CNRS, Microbiologie Fondamentale et Pathogénicité, UMR 5234, 33000 Bordeaux, France
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Arendrup MC, Arikan-Akdagli S, Jørgensen KM, Barac A, Steinmann J, Toscano C, Arsenijevic VA, Sartor A, Lass-Flörl C, Hamprecht A, Matos T, Rogers BRS, Quiles I, Buil J, Özenci V, Krause R, Bassetti M, Loughlin L, Denis B, Grancini A, White PL, Lagrou K, Willinger B, Rautemaa-Richardson R, Hamal P, Ener B, Unalan-Altintop T, Evren E, Hilmioglu-Polat S, Oz Y, Ozyurt OK, Aydin F, Růžička F, Meijer EFJ, Gangneux JP, Lockhart DEA, Khanna N, Logan C, Scharmann U, Desoubeaux G, Roilides E, Talento AF, van Dijk K, Koehler P, Salmanton-García J, Cornely OA, Hoenigl M. European candidaemia is characterised by notable differential epidemiology and susceptibility pattern: Results from the ECMM Candida III study. J Infect 2023; 87:428-437. [PMID: 37549695 DOI: 10.1016/j.jinf.2023.08.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 07/25/2023] [Accepted: 08/03/2023] [Indexed: 08/09/2023]
Abstract
The objectives of this study were to assess Candida spp. distribution and antifungal resistance of candidaemia across Europe. Isolates were collected as part of the third ECMM Candida European multicentre observational study, conducted from 01 to 07-07-2018 to 31-03-2022. Each centre (maximum number/country determined by population size) included ∼10 consecutive cases. Isolates were referred to central laboratories and identified by morphology and MALDI-TOF, supplemented by ITS-sequencing when needed. EUCAST MICs were determined for five antifungals. fks sequencing was performed for echinocandin resistant isolates. The 399 isolates from 41 centres in 17 countries included C. albicans (47.1%), C. glabrata (22.3%), C. parapsilosis (15.0%), C. tropicalis (6.3%), C. dubliniensis and C. krusei (2.3% each) and other species (4.8%). Austria had the highest C. albicans proportion (77%), Czech Republic, France and UK the highest C. glabrata proportions (25-33%) while Italy and Turkey had the highest C. parapsilosis proportions (24-26%). All isolates were amphotericin B susceptible. Fluconazole resistance was found in 4% C. tropicalis, 12% C. glabrata (from six countries across Europe), 17% C. parapsilosis (from Greece, Italy, and Turkey) and 20% other Candida spp. Four isolates were anidulafungin and micafungin resistant/non-wild-type and five resistant to micafungin only. Three/3 and 2/5 of these were sequenced and harboured fks-alterations including a novel L657W in C. parapsilosis. The epidemiology varied among centres and countries. Acquired echinocandin resistance was rare but included differential susceptibility to anidulafungin and micafungin, and resistant C. parapsilosis. Fluconazole and voriconazole cross-resistance was common in C. glabrata and C. parapsilosis but with different geographical prevalence.
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Affiliation(s)
- Maiken Cavling Arendrup
- Unit of Mycology, Statens Serum Institut, Copenhagen, Denmark; Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
| | - Sevtap Arikan-Akdagli
- Department of Medical Microbiology, Hacettepe University Medical School, Ankara, Turkey
| | | | - Aleksandra Barac
- Clinic for Infectious and Tropical Diseases, University Clinical Center of Serbia, Belgrade, Serbia
| | - Jörg Steinmann
- Institute for Clincal Hygiene, Medical Microbiology and Infectiology, Paracelsus Medical University, Klinikum Nürnberg, Nuremberg, Germany
| | - Cristina Toscano
- Microbiology Laboratory, Centro Hospitalar de Lisboa Ocidental, Lisboa, Portugal
| | - Valentina Arsic Arsenijevic
- Faculty of Medicine University of Belgrade, Institute of Microbiology and Immunology, Medical Mycology Reference Laboratory (MMRL), Belgrade, Serbia
| | - Assunta Sartor
- SC Microbiology, Department of Laboratory Medicine, Friuli Centrale University Health Authority, Udin, Italy
| | - Cornelia Lass-Flörl
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Axel Hamprecht
- University of Cologne, University Hospital Cologne, Institute for Medical Microbiology, Immunology and Hygiene, Cologne, Germany; University of Oldenburg, Institute for Medical Microbiology and Virology, Oldenburg, Germany
| | - Tadeja Matos
- Institute of Microbiology and Immunology, Medical Faculty, University of Ljubljana, Slovenia
| | - Benedict R S Rogers
- Department of Clinical Microbiology, University Hospitals of Leicester NHS Trust, Leicester, United Kingdom
| | - Inmaculada Quiles
- Department of Microbiology, La Paz University Hospital, Madrid, Spain
| | - Jochem Buil
- Canisius Wilhelmina Hospital (CWZ), Medical Microbiology and Infectious Diseases, Nijmegen, the Netherlands; Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands; Center of Expertise in Mycology Radboudumc/CWZ, Nijmegen, the Netherlands
| | - Volkan Özenci
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Sweden; Department of Clinical Microbiology, Karolinska University Hospital, Huddinge, Stockholm, Sweden
| | - Robert Krause
- Biotech Med, Graz, Austria; Division of Infectious Diseases, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Matteo Bassetti
- Infectious Diseases Unit, IRCCS San Martino Polyclinic Hospital, Genoa, Italy; Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
| | - Laura Loughlin
- Belfast Health and Social Care Trust, Belfast, United Kingdom
| | - Blandine Denis
- Department of Infectious Diseases, Hôpital Saint-Louis, Fernand Widal, Lariboisière, AP-HP, Paris, France
| | - Anna Grancini
- U.O.S Microbiology - Analysis Laboratory, IRCCS Foundation, Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - P Lewis White
- Public Health Wales Microbiology Cardiff and Cardiff University School of Medicine, United Kingdom
| | - Katrien Lagrou
- Department of Microbiology, Immunology and Transplantation, KU Leuven, Leuven, Belgium; Department of Laboratory Medicine and National Reference Center for Mycosis University Hospitals Leuven, Leuven, Belgium
| | - Birgit Willinger
- Division of Clinical Microbiology, Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Riina Rautemaa-Richardson
- Mycology Reference Centre Manchester and Department of Infectious Diseases, Wythenshawe Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom; Division of Evolution, Infection and Genomics, Faculty of Biology, Medicine and Health, University of Manchester, United Kingdom
| | - Petr Hamal
- Department of Microbiology, Faculty of Medicine and Dentistry, Palacky University Olomouc, Olomouc, Czech Republic
| | - Beyza Ener
- Department of Medical Microbiology, Bursa Uludağ University Medical School, Bursa, Turkey
| | - Tugce Unalan-Altintop
- Department of Medical Microbiology, Hacettepe University Medical School, Ankara, Turkey
| | - Ebru Evren
- Department of Medical Microbiology, Ankara University Medical School, Ankara, Turkey
| | | | - Yasemin Oz
- Department of Medical Microbiology, Eskisehir Osmangazi University Medical School, Eskisehir, Turkey
| | - Ozlem Koyuncu Ozyurt
- Department of Medical Microbiology, Akdeniz University Medical School, Antalya, Turkey
| | - Faruk Aydin
- KTÜ Tıp Fakültesi Tıbbi Mikrobiyoloji AbD, Trabzon, Turkey
| | - Filip Růžička
- Masaryk University, Faculty of Medicine and St. Anne's Faculty Hospital, Department of Microbiology, Brno, Czech Republic
| | - Eelco F J Meijer
- Canisius Wilhelmina Hospital (CWZ), Medical Microbiology and Infectious Diseases, Nijmegen, the Netherlands; Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, the Netherlands; Center of Expertise in Mycology Radboudumc/CWZ, Nijmegen, the Netherlands
| | - Jean Pierre Gangneux
- Univ Rennes, CHU Rennes, Inserm, EHESP, Irset (Institut de recherche en santé, environnement et travail), UMR_S 1085, F-35000 Rennes, France
| | - Deborah E A Lockhart
- Department of Medical Microbiology, Aberdeen Royal Infirmary, Foresterhill, Aberdeen AB25 2ZN, United Kingdom; Institute of Medical Sciences, School of Medicine Medical Sciences & Nutrition, University of Aberdeen, Aberdeen AB25 2ZD, United Kingdom
| | - Nina Khanna
- Division of Infectious Diseases and Hospital Epidemiology, University Hospital of Basel, Basel, Switzerland
| | - Clare Logan
- Clinical Infection Unit, St Georges University NHS Hospital Foundation Trust, Blackshaw Road, London, United Kingdom; Institute of Infection & Immunity, St Georges University London, Cranmer Terrace, London, United Kingdom
| | - Ulrike Scharmann
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Guillaume Desoubeaux
- Department of Parasitology-Mycology-Tropical medicine, CHRU Tours, Tours, France
| | - Emmanuel Roilides
- Hippokration General Hospital, Infectious Diseases Department, Medical School, Aristotle University of Thessaloniki, Greece
| | | | - Karin van Dijk
- Department of Medical Microbiology and Infection Control, Amsterdam University Medical Centers, Academic Medical Center, Amsterdam Infection and Immunity Institute, Amsterdam, the Netherlands
| | - Philipp Koehler
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Department I of Internal Medicine, and Excellence Center for Medical Mycology (ECMM), Cologne, Germany; University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Institute of Translational Research, Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Jon Salmanton-García
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Department I of Internal Medicine, and Excellence Center for Medical Mycology (ECMM), Cologne, Germany; University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Institute of Translational Research, Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Oliver A Cornely
- University of Cologne, Faculty of Medicine and University Hospital Cologne, Department I of Internal Medicine, and Excellence Center for Medical Mycology (ECMM), Cologne, Germany; University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Institute of Translational Research, Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), Cologne, Germany
| | - Martin Hoenigl
- Biotech Med, Graz, Austria; Division of Infectious Diseases, Department of Internal Medicine, Medical University of Graz, Graz, Austria.
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Silva LN, Ramos LS, Oliveira SSC, Magalhães LB, Cypriano J, Abreu F, Macedo AJ, Branquinha MH, Santos ALS. Development of Echinocandin Resistance in Candida haemulonii: An Emergent, Widespread, and Opportunistic Fungal Pathogen. J Fungi (Basel) 2023; 9:859. [PMID: 37623630 PMCID: PMC10455776 DOI: 10.3390/jof9080859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/11/2023] [Accepted: 08/17/2023] [Indexed: 08/26/2023] Open
Abstract
Echinocandins, used for the prevention and treatment of invasive fungal infections, have led to a rise in breakthrough infections caused by resistant Candida species. Among these species, those belonging to the Candida haemulonii complex are rare multidrug-resistant (MDR) yeasts that are frequently misidentified but have emerged as significant healthcare-associated pathogens causing invasive infections. The objectives of this study were to investigate the evolutionary pathways of echinocandin resistance in C. haemulonii by identifying mutations in the FKS1 gene and evaluating the impact of resistance on fitness. After subjecting a MDR clinical isolate of C. haemulonii (named Ch4) to direct selection using increasing caspofungin concentrations, we successfully obtained an isolate (designated Ch4'r) that exhibited a high level of resistance, with MIC values exceeding 16 mg/L for all tested echinocandin drugs (caspofungin, micafungin, and anidulafungin). Sequence analysis revealed a specific mutation in the resistant Ch4'r strain, leading to an arginine-histidine amino acid substitution (R1354H), occurring at the G4061A position of the HS2 region of the FKS1 gene. Compared to the wild-type strain, Ch4'r exhibited significantly reduced growth proliferation, biofilm formation capability, and phagocytosis ratio, indicating a decrease in fitness. Transmission electron microscopy analysis revealed alterations in cell wall components, with a notable increase in cell wall thickness. The resistant strain also exhibited higher amounts (2.5-fold) of chitin, a cell wall-located molecule, compared to the wild-type strain. Furthermore, the resistant strain demonstrated attenuated virulence in the Galleria mellonella larval model. The evolved strain Ch4'r maintained its resistance profile in vivo since the treatment with either caspofungin or micafungin did not improve larval survival or reduce the fungal load. Taken together, our findings suggest that the acquisition of pan-echinocandin resistance occurred rapidly after drug exposure and was associated with a significant fitness cost in C. haemulonii. This is particularly concerning as echinocandins are often the first-line treatment option for MDR Candida species.
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Affiliation(s)
- Laura N. Silva
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes (LEAMER), Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil; (L.N.S.); (L.S.R.); (S.S.C.O.); (L.B.M.); (M.H.B.)
| | - Lívia S. Ramos
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes (LEAMER), Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil; (L.N.S.); (L.S.R.); (S.S.C.O.); (L.B.M.); (M.H.B.)
| | - Simone S. C. Oliveira
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes (LEAMER), Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil; (L.N.S.); (L.S.R.); (S.S.C.O.); (L.B.M.); (M.H.B.)
| | - Lucas B. Magalhães
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes (LEAMER), Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil; (L.N.S.); (L.S.R.); (S.S.C.O.); (L.B.M.); (M.H.B.)
| | - Jefferson Cypriano
- Laboratório de Biologia Celular e Magnetotaxia & Unidade de Microscopia Multiusuário, Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil; (J.C.); (F.A.)
| | - Fernanda Abreu
- Laboratório de Biologia Celular e Magnetotaxia & Unidade de Microscopia Multiusuário, Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil; (J.C.); (F.A.)
| | - Alexandre J. Macedo
- Laboratório de Biofilmes e Diversidade Microbiana, Centro de Biotecnologia e Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre 90010-150, Brazil;
| | - Marta H. Branquinha
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes (LEAMER), Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil; (L.N.S.); (L.S.R.); (S.S.C.O.); (L.B.M.); (M.H.B.)
- Programa de Pós-Graduação em Bioquímica (PPGBq), Instituto de Química (IQ), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-853, Brazil
| | - André L. S. Santos
- Laboratório de Estudos Avançados de Microrganismos Emergentes e Resistentes (LEAMER), Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-902, Brazil; (L.N.S.); (L.S.R.); (S.S.C.O.); (L.B.M.); (M.H.B.)
- Programa de Pós-Graduação em Bioquímica (PPGBq), Instituto de Química (IQ), Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro 21941-853, Brazil
- Rede Micologia RJ—Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), Rio de Janeiro 21941-902, Brazil
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Desnos-Ollivier M, Bretagne S, Lortholary O, Dromer F; French Mycoses Study Group N. Brieu CH Aix, T. Chouaki , C. Damiani , A. Totet CHU Amiens, J. P. Bouchara , D. Chabasse , M. Pihet CHU Angers, S. Bland CH Annecy, V. Blanc CH Antibes, S. Branger CH Avignon, A. P. Bellanger , L. Millon CHU Besançon, C. Plassart CH Beauvais, I. Poilane Hôpital Jean Verdier, Bondy, I. Accoceberry , L. Delhaes , B. Couprie , F. Gabriel CH Bordeaux, J. Dunand , A. L. Roux , V. Sivadon-Tardy Hôpital Ambroise Paré, Boulogne Billancourt, F. Laurent CH, Bourg en Bresse, S. Legal , E. Moalic , G. Nevez , D. Quinio CHU Brest, M. Cariou CH Bretagne Sud, J. Bonhomme , C. Duhamel CHU, Caen, B. Podac CH, Chalon sur Saône, S. Lechatch CH, Charleville-Mézières, C. Soler Hopital d’Instruction des armées, Clamart, M. Cambon , C. Nourrisson , P. Poirier , D. Pons CHU, Clermont Ferrand, O. Augereau , I. Grawey CH, Colmar, N. Fauchet CHIC, Créteil, A. Bonnin , F. Dalle CHU, Dijon, P. Cahen , P. Honderlick CMC, Foch, N. Desbois , C. Miossec CHU, Fort de France, J. L. Hermann Hôpital Raymond Poincaré, Garches, M. Cornet , R. Grillot , B. Lebeau , D. Maubon , H. Pelloux CHU, Grenoble, M. Nicolas CHU, Guadeloupe, C. Aznar , D. Blanchet , J. F. Carod , M. Demar CHU, Guyane, A. Angoulvant Hôpital Bicêtre, le Kremlin Bicêtre, C. Ciupek CH, Le Mans, A. Gigandon Hôpital Marie Lannelongue, Le Plessis Robinson, B. Bouteille CH Limoges, E. Frealle , D. Poulain , B. Sendid CHU Lille, D. Dupont , J. Menotti , F. Persat , M.-A. Piens , M. Wallon CHU, Lyon, C. Cassagne , S. Ranque CHU, Marseille, T. Benoit-Cattin , L. Collet CH Mayotte, A. Fiacre CH Meaux, N. Bourgeois , L. Lachaud , P. Rispail , Y. Sterkers CHU, Montpellier, M. Machouart CHU, Nancy, F. Gay-Andrieu , P. Lepape , F. Morio CHU, Nantes, O. Moquet CH, Nevers, S. Lefrançois Hôpital Américain, Neuilly, M. Sasso CHU, Nimes, F. Reibel GH, Nord-Essone, M. Gari-Toussaint , L. Hasseine CHU Nice, L. Bret , D. Poisson CHR Orléans, S. Brun Hôpital Avicenne, Paris, C. Bonnal , C. Chochillon , S. Houzé Hôpital Bichat, Paris, A. Paugam Hôpital Cochin, Paris, N. Ait-Ammar , F. Botterel , R. Chouk CHU Henri Mondor, Paris, M. E. Bougnoux , E. Sitterle Hôpital Necker, Paris, A. Fekkar , R. Piarroux Hôpital Pitié Salpêtrière, Paris, J. Guitard , C. Hennequin , J.-L. Poirot Hôpital St Antoine, Paris, M. Gits-Muselli , S. Hamane , C. Lacroix Hôpital Saint Louis, Paris, S. Bonacorsi , P. Mariani Hôpital Robert Debré, Paris, D. Moissenet Hôpital Trousseau, Paris, C. Kauffmann-Lacroix , A. Minoza , E. Perraud , M. H. Rodier CHU Poitiers, G. Colonna CH, Porto Vecchio, A. Huguenin , D. Toubas CHU Reims, S. Chevrier , J. P. Gangneux , F. Robert-Gangneux , C. Guigen CHU Rennes, O. Belmonte , G. Hoarau , M. C. Jaffar Bandjee , J. Jaubert , S. Picot , N. Traversier CHU Réunion, L. Favennec , G. Gargala CHU, Rouen, N. Godineau , C. Tournus CH, St Denis, C. Mahinc , H. Raberin CHU, St Etienne, V. Letscher Bru CHU, Strasbourg, S. Cassaing CHU, Toulouse, P. Patoz CH Tourcoing, E. Bailly , J. Chandenier , G. Desoubeaux CHU Tours, F. Moreau CH Troyes, P. Munier CH Valence, E. Mazars CH Valenciennes, O. Eloy CH Versailles, E. Chachaty Institut Gustave Roussy, Villejuif . Echinocandins Susceptibility Patterns of 2,787 Yeast Isolates: Importance of the Thresholds for the Detection of FKS Mutations. Antimicrob Agents Chemother 2022;:e0172521. [PMID: 35412354 DOI: 10.1128/aac.01725-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Since echinocandins are recommended as first line therapy for invasive candidiasis, detection of resistance, mainly due to alteration in FKS protein, is of main interest. EUCAST AFST recommends testing both MIC of anidulafungin and micafungin, and breakpoints (BPs) have been proposed to detect echinocandin-resistant isolates. We analyzed MIC distribution for all three available echinocandins of 2,787 clinical yeast isolates corresponding to 5 common and 16 rare yeast species, using the standardized EUCAST method for anidulafungin and modified for caspofungin and micafungin (AM3-MIC). In our database, 64 isolates of common pathogenic species were resistant to anidulafungin, according to the EUCAST BP, and/or to caspofungin, using our previously published threshold (AM3-MIC ≥ 0.5 mg/L). Among these 64 isolates, 50 exhibited 21 different FKS mutations. We analyzed the capacity of caspofungin AM3-MIC and anidulafungin MIC determination in detecting isolates with FKS mutation. They were always identified using caspofungin AM3-MIC and the local threshold while some isolates were misclassified using anidulafungin MIC and EUCAST threshold. However, both methods misclassified four wild-type C. glabrata as resistant. Based on a large data set from a single center, the use of AM3-MIC testing for caspofungin looks promising in identifying non-wild-type C. albicans, C. tropicalis and P. kudiravzevii isolates, but additional multicenter comparison is mandatory to conclude on the possible superiority of AM3-MIC testing compared to the EUCAST method.
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7
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Perrine-Walker F. Caspofungin resistance in Candida albicans: genetic factors and synergistic compounds for combination therapies. Braz J Microbiol 2022; 53:1101-1113. [PMID: 35352319 PMCID: PMC9433586 DOI: 10.1007/s42770-022-00739-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 03/25/2022] [Indexed: 11/25/2022] Open
Abstract
Caspofungin and other echinocandins have been used for the treatment of human infections by the opportunistic yeast pathogen, Candida albicans. There has been an increase in infections by non-albicans Candida species such as Candida glabrata, Candida parapsilosis, Candida tropicalis, Candida krusei, and Candida auris in clinical or hospital settings. This is problematic to public health due to the increasing prevalence of echinocandin resistant species/strains. This review will present a summary on various studies that investigated the inhibitory action of caspofungin on 1,3-β-D-glucan synthesis, on cell wall structure, and biofilm formation of C. albicans. It will highlight some of the issues linked to caspofungin resistance or reduced caspofungin sensitivity in various Candida species and the potential benefits of antimicrobial peptides and other compounds in synergy with caspofungin.
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Affiliation(s)
- Francine Perrine-Walker
- Department of Biochemistry and Genetics, La Trobe Institute For Molecular Science, La Trobe University, Bundoora, VIC, 3086, Australia.
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8
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Kim HY, Baldelli S, Märtson AG, Stocker S, Alffenaar JW, Cattaneo D, Marriott DJE. Therapeutic Drug Monitoring of the Echinocandin Antifungal Agents: Is There a Role in Clinical Practice? A Position Statement of the Anti-Infective Drugs Committee of the International Association of Therapeutic Drug Monitoring and Clinical Toxicology. Ther Drug Monit 2022; 44:198-214. [PMID: 34654030 DOI: 10.1097/ftd.0000000000000931] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 09/01/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE Reduced exposure to echinocandins has been reported in specific patient populations, such as critically ill patients; however, fixed dosing strategies are still used. The present review examines the accumulated evidence supporting echinocandin therapeutic drug monitoring (TDM) and summarizes available assays and sampling strategies. METHODS A literature search was conducted using PubMed in December 2020, with search terms such as echinocandins, anidulafungin, caspofungin, micafungin, or rezafungin with pharmacology, pharmacokinetics (PKs), pharmacodynamics (PDs), drug-drug interactions, TDM, resistance, drug susceptibility testing, toxicity, adverse drug reactions, bioanalysis, chromatography, and mass spectrometry. Data on PD/PD (PK/PD) outcome markers, drug resistance, PK variability, drug-drug interactions, assays, and TDM sampling strategies were summarized. RESULTS Echinocandins demonstrate drug exposure-efficacy relationships, and maximum concentration/minimal inhibitory concentration ratio (Cmax/MIC) and area under the concentration-time curve/MIC ratio (AUC/MIC) are proposed PK/PD markers for clinical response. The relationship between drug exposure and toxicity remains poorly clarified. TDM could be valuable in patients at risk of low drug exposure, such as those with critical illness and/or obesity. TDM of echinocandins may also be useful in patients with moderate liver impairment, drug-drug interactions, hypoalbuminemia, and those undergoing extracorporeal membrane oxygenation, as these conditions are associated with altered exposure to caspofungin and/or micafungin. Assays are available to measure anidulafungin, micafungin, and caspofungin concentrations. A limited-sampling strategy for anidulafungin has been reported. CONCLUSIONS Echinocandin TDM should be considered in patients at known risk of suboptimal drug exposure. However, for implementing TDM, clinical validation of PK/PD targets is needed.
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Affiliation(s)
- Hannah Yejin Kim
- Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
- Westmead Hospital, Westmead, NSW, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Camperdown, NSW, Australia
| | - Sara Baldelli
- Unit of Clinical Pharmacology, Fatebenefratelli Sacco University Hospital, Milan, Italy
| | - Anne-Grete Märtson
- Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands
| | - Sophie Stocker
- Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
- St Vincent's Clinical School, University of New South Wales, Kensington, NSW Australia; and
| | - Jan-Willem Alffenaar
- Sydney Pharmacy School, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
- Westmead Hospital, Westmead, NSW, Australia
- Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Camperdown, NSW, Australia
| | - Dario Cattaneo
- Unit of Clinical Pharmacology, Fatebenefratelli Sacco University Hospital, Milan, Italy
- Gestione Ambulatoriale Politerapie (GAP) Outpatient Clinic, ASST Fatebenefratelli Sacco University Hospital, Milan, Italy
| | - Deborah J E Marriott
- St Vincent's Clinical School, University of New South Wales, Kensington, NSW Australia; and
- Department of Microbiology and Infectious Diseases, St. Vincent's Hospital, Darlinghurst, NSW, Australia
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9
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Hammi KM, Essid R, Khadraoui N, Ksouri R, Majdoub H, Tabbene O. Antimicrobial, antioxidant and antileishmanial activities of Ziziphus lotus leaves. Arch Microbiol 2022; 204:119. [PMID: 34989872 DOI: 10.1007/s00203-021-02733-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 12/04/2021] [Accepted: 12/17/2021] [Indexed: 11/28/2022]
Abstract
The aim of this study was to investigate antimicrobial and antioxidant activities of different fractions obtained from edible Tunisian Ziziphus Lotus leaves of Tozeur region. Different organic extracts were tested: cyclohexane, dichloromethane, ethyl acetate, n-butanol and water. Bio-guided fractionation revealed that dichloromethane fraction is the most active against S. aureus and Methicillin-resistant S. aureus strains. Moreover, this fraction showed the highest antileishmanial activity with IC50 values of 20.55 ± 0.34 μg/mL and 15.37 ± 0.17 μg/mL against L. major and L. infantum, respectively. The potentialities of antibacterial and leishmanicidal activities found in dichloromethane could be explained by the presence of major flavonoids such as catechin, rutin and luteolin 7-O-glucoside as revealed by HPLC system. The observed moderate antifungal activity, which was only given by butanolic fraction against pathogen fungi, may be attributed to the presence of chlorogenic acid. Furthermore, dichloromethane and butanolic fraction showed a good DPPH (2,2-diphenyl-1-picryl hydrazyl) scavenging activity and Ferric reducing power. These results suggest that Ziziphus lotus leaf fractions might be used as antioxidant and antimicrobialagent.
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Affiliation(s)
- Khaoula Mkadmini Hammi
- Laboratoire des Plantes Aromatiques et Médicinales (LPAM), Centre de Biotechnologie de Borj-Cédria, BP 901, 2050, Hammam-Lif, Tunisia.,Laboratoire des Interfaces et des Matériaux Avancés (LIMA), Faculté des Sciences de Monastir, Université de Monastir, Bd. de l'environnement, 5019, Monastir, Tunisia
| | - Rym Essid
- Laboratoire des Substances Bioactives, Centre de Biotechnologie de Borj-Cédria, BP 901, 2050, Hammam-Lif, Tunisia.
| | - Nadine Khadraoui
- Laboratoire des Substances Bioactives, Centre de Biotechnologie de Borj-Cédria, BP 901, 2050, Hammam-Lif, Tunisia
| | - Riadh Ksouri
- Laboratoire des Plantes Aromatiques et Médicinales (LPAM), Centre de Biotechnologie de Borj-Cédria, BP 901, 2050, Hammam-Lif, Tunisia
| | - Hatem Majdoub
- Laboratoire des Interfaces et des Matériaux Avancés (LIMA), Faculté des Sciences de Monastir, Université de Monastir, Bd. de l'environnement, 5019, Monastir, Tunisia
| | - Olfa Tabbene
- Laboratoire des Substances Bioactives, Centre de Biotechnologie de Borj-Cédria, BP 901, 2050, Hammam-Lif, Tunisia
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10
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Abstract
The increasing incidence and changing epidemiology of invasive fungal infections continue to present many challenges to their effective management. The repertoire of antifungal drugs available for treatment is still limited although there are new antifungals on the horizon. Successful treatment of invasive mycoses is dependent on a mix of pathogen-, host- and antifungal drug-related factors. Laboratories need to be adept at detection of fungal pathogens in clinical samples in order to effectively guide treatment by identifying isolates with acquired drug resistance. While there are international guidelines on how to conduct in vitro antifungal susceptibility testing, these are not performed as widely as for bacterial pathogens. Furthermore, fungi generally are recovered in cultures more slowly than bacteria, and often cannot be cultured in the laboratory. Therefore, non-culture-based methods, including molecular tests, to detect fungi in clinical specimens are increasingly important in patient management and are becoming more reliable as technology improves. Molecular methods can also be used for detection of target gene mutations or other mechanisms that predict antifungal drug resistance. This review addresses acquired antifungal drug resistance in the principal human fungal pathogens and describes known resistance mechanisms and what in-house and commercial tools are available for their detection. It is emphasized that this approach should be complementary to culture-based susceptibility testing, given the range of mutations, resistance mechanisms and target genes that may be present in clinical isolates, but may not be included in current molecular assays.
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Affiliation(s)
| | | | | | | | | | - Maiken Cavling Arendrup
- Unit of Mycology, Statens Serum Institut, Copenhagen, Denmark
- Department of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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11
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Chakraborty A, Jasieniak M, Coad BR, Griesser HJ. Candida albicans Can Survive Antifungal Surface Coatings on Surfaces with Microcone Topography. ACS Appl Bio Mater 2021; 4:7769-7778. [PMID: 35006760 DOI: 10.1021/acsabm.1c00307] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
This study demonstrates the ability of Candida albicans, a medically significant human fungal pathogen, to minimize contact with an antifungal surface coating that on a flat surface is lethal on contact by growing on and between micron-sized surface topographical features, thus minimizing the contact area. Scanning electron microscopy showed that cells contacting the "floor" between microcones were killed, whereas cells attached to microcones survived and formed hyphal filaments. These spanned space between cones and avoided contact with the flat surface in-between cones. Thus, fungal cells managed to attach and grow despite the antifungal coating. This ability of Candida albicans to exploit topography features to minimize surface contact yet utilize the solid surface for anchoring reduces the effectiveness of the grafted antifungal surface coating. This suggests that biomedical devices with rough surfaces might be more challenging to protect against fungal biofilm formation via application of an antifungal coating.
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Affiliation(s)
- Argha Chakraborty
- Future Industries Institute, University of South Australia, Mawson Lakes, South Australia 5095, Australia.,Cooperative Research Centre for Cell Therapy Manufacturing, Adelaide, South Australia 5000, Australia
| | - Marek Jasieniak
- Future Industries Institute, University of South Australia, Mawson Lakes, South Australia 5095, Australia.,Cooperative Research Centre for Cell Therapy Manufacturing, Adelaide, South Australia 5000, Australia
| | - Bryan R Coad
- Future Industries Institute, University of South Australia, Mawson Lakes, South Australia 5095, Australia.,School of Agriculture, Food and Wine, University of Adelaide, Urrbrae, South Australia 5064, Australia
| | - Hans J Griesser
- Future Industries Institute, University of South Australia, Mawson Lakes, South Australia 5095, Australia.,Cooperative Research Centre for Cell Therapy Manufacturing, Adelaide, South Australia 5000, Australia
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12
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Hoenigl M, Sprute R, Egger M, Arastehfar A, Cornely OA, Krause R, Lass-Flörl C, Prattes J, Spec A, Thompson GR, Wiederhold N, Jenks JD. The Antifungal Pipeline: Fosmanogepix, Ibrexafungerp, Olorofim, Opelconazole, and Rezafungin. Drugs 2021; 81:1703-1729. [PMID: 34626339 PMCID: PMC8501344 DOI: 10.1007/s40265-021-01611-0] [Citation(s) in RCA: 149] [Impact Index Per Article: 49.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/09/2021] [Indexed: 01/08/2023]
Abstract
The epidemiology of invasive fungal infections is changing, with new populations at risk and the emergence of resistance caused by the selective pressure from increased usage of antifungal agents in prophylaxis, empiric therapy, and agriculture. Limited antifungal therapeutic options are further challenged by drug-drug interactions, toxicity, and constraints in administration routes. Despite the need for more antifungal drug options, no new classes of antifungal drugs have become available over the last 2 decades, and only one single new agent from a known antifungal class has been approved in the last decade. Nevertheless, there is hope on the horizon, with a number of new antifungal classes in late-stage clinical development. In this review, we describe the mechanisms of drug resistance employed by fungi and extensively discuss the most promising drugs in development, including fosmanogepix (a novel Gwt1 enzyme inhibitor), ibrexafungerp (a first-in-class triterpenoid), olorofim (a novel dihyroorotate dehydrogenase enzyme inhibitor), opelconazole (a novel triazole optimized for inhalation), and rezafungin (an echinocandin designed to be dosed once weekly). We focus on the mechanism of action and pharmacokinetics, as well as the spectrum of activity and stages of clinical development. We also highlight the potential future role of these drugs and unmet needs.
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Affiliation(s)
- Martin Hoenigl
- Division of Infectious Diseases, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria.
- Division of Infectious Diseases and Global Public Health, Department of Medicine, University of California San Diego, La Jolla, San Diego, CA, USA.
- Clinical and Translational Fungal-Working Group, University of California San Diego, La Jolla, San Diego, CA, USA.
| | - Rosanne Sprute
- Department I of Internal Medicine, Excellence Center for Medical Mycology (ECMM), University Hospital Cologne, Faculty of Medicine, University of Cologne, Cologne, Germany
- Chair Translational Research, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University Hospital Cologne, Faculty of Medicine, University of Cologne, Cologne, Germany
- German Centre for Infection Research (DZIF), Partner Site Bonn-Cologne, Cologne, Germany
| | - Matthias Egger
- Division of Infectious Diseases, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Amir Arastehfar
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ, USA
| | - Oliver A Cornely
- Department I of Internal Medicine, Excellence Center for Medical Mycology (ECMM), University Hospital Cologne, Faculty of Medicine, University of Cologne, Cologne, Germany
- Chair Translational Research, Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University Hospital Cologne, Faculty of Medicine, University of Cologne, Cologne, Germany
- German Centre for Infection Research (DZIF), Partner Site Bonn-Cologne, Cologne, Germany
- Clinical Trials Centre Cologne (ZKS Köln), University Hospital Cologne, Faculty of Medicine, University of Cologne, Cologne, Germany
| | - Robert Krause
- Division of Infectious Diseases, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Cornelia Lass-Flörl
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Juergen Prattes
- Division of Infectious Diseases, Department of Internal Medicine, Medical University of Graz, Auenbruggerplatz 15, 8036, Graz, Austria
| | - Andrej Spec
- Division of Infectious Diseases, Department of Medicine, Washington University School of Medicine, St. Louis, MI, USA
| | - George R Thompson
- Division of Infectious Diseases, Departments of Internal Medicine and Medical Microbiology and Immunology, University of California Davis Medical Center, Sacramento, CA, USA
| | - Nathan Wiederhold
- Department of Pathology and Laboratory Medicine, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Jeffrey D Jenks
- Division of Infectious Diseases and Global Public Health, Department of Medicine, University of California San Diego, La Jolla, San Diego, CA, USA
- Clinical and Translational Fungal-Working Group, University of California San Diego, La Jolla, San Diego, CA, USA
- Division of General Internal Medicine, Department of Medicine, University of California San Diego, La Jolla, San Diego, CA, USA
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13
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Rollin-Pinheiro R, Bayona-Pacheco B, Domingos LTS, da Rocha Curvelo JA, de Castro GMM, Barreto-Bergter E, Ferreira-Pereira A. Sphingolipid Inhibitors as an Alternative to Treat Candidiasis Caused by Fluconazole-Resistant Strains. Pathogens 2021; 10:856. [PMID: 34358009 DOI: 10.3390/pathogens10070856] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Revised: 07/01/2021] [Accepted: 07/03/2021] [Indexed: 11/19/2022] Open
Abstract
Candida species are fungal pathogens known to cause a wide spectrum of diseases, and Candida albicans and Candida glabrata are the most common associated with invasive infections. A concerning aspect of invasive candidiasis is the emergence of resistant isolates, especially those highly resistant to fluconazole, the first choice of treatment for these infections. Fungal sphingolipids have been considered a potential target for new therapeutic approaches and some inhibitors have already been tested against pathogenic fungi. The present study therefore aimed to evaluate the action of two sphingolipid synthesis inhibitors, aureobasidin A and myriocin, against different C. albicans and C. glabrata strains, including clinical isolates resistant to fluconazole. Susceptibility tests of aureobasidin A and myriocin were performed using CLSI protocols, and their interaction with fluconazole was evaluated by a checkerboard protocol. All Candida strains tested were sensitive to both inhibitors. Regarding the evaluation of drug interaction, both aureobasidin A and myriocin were synergic with fluconazole, demonstrating that sphingolipid synthesis inhibition could enhance the effect of fluconazole. Thus, these results suggest that sphingolipid inhibitors in conjunction with fluconazole could be useful for treating candidiasis cases, especially those caused by fluconazole resistant isolates.
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14
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Marzuttini F, Mancusi A, Bonato S, Griselli M, Tricarico S, Casarola G, Paradiso M, Ruggeri L, Terenzi A, Merluzzi M, Prigitano A, Tortorano AM, Pitzurra L, Falini B, Carotti A, Velardi A, Pierini A. Rifaximin use favoured micafungin-resistant Candida spp. infections in recipients of allogeneic hematopoietic cell transplantation. Ann Hematol 2021; 100:2375-80. [PMID: 34180023 DOI: 10.1007/s00277-021-04569-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 06/04/2021] [Indexed: 10/25/2022]
Abstract
Damage to gut mucosa following conditioning regimens may favour bacterial infections that can trigger graft versus host disease (GvHD) in patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT). Rifaximin, an oral and non-absorbable antibiotic, has been recently proposed as effective prophylaxis to reduce bacterial infections in the gut and consequently acute GvHD in this setting. The present study evaluated safety and outcomes of HSCT patients that were treated with rifaximin prophylaxis at Perugia University Hospital. Rifaximin prophylaxis was introduced as standard of care in HSCT patients in May 2018. We retrieved data from 118 consecutive transplants, and we compared the outcomes of rifaximin-treated patients with historical controls that did not receive antibiotic prophylaxis. While incidences of neutropenic fever, documented bacterial infections, and aGvHD were similar in the two groups, we found an increased frequency of invasive candidiasis and clinically relevant Candida spp. infections in rifaximin-treated patients (5 patients vs 1 patient, 25% [± 0.99%] vs 1% [± 0.01%], p < .0001). Three rifaximin-treated patients experienced life-threating candidemia (2 C. krusei, 1 C. orthopsilosis). Rifaximin was the only factor that increased the risk of Candida spp. infections. Rifaximin could have contributed to microbiome disruption which favoured an outbreak of life-threatening Candida infections. This important complication forced us to halt its use. Larger, prospective studies are needed to assess the impact of rifaximin prophylaxis on incidence of bacterial infections, aGvHD, and survival of HSCT patients.
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15
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Sitterlé E, Coste AT, Obadia T, Maufrais C, Chauvel M, Sertour N, Sanglard D, Puel A, D'Enfert C, Bougnoux ME. Large-scale genome mining allows identification of neutral polymorphisms and novel resistance mutations in genes involved in Candida albicans resistance to azoles and echinocandins. J Antimicrob Chemother 2021; 75:835-848. [PMID: 31923309 DOI: 10.1093/jac/dkz537] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/22/2019] [Accepted: 12/01/2019] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND The genome of Candida albicans displays significant polymorphism. Point mutations in genes involved in resistance to antifungals may either confer phenotypic resistance or be devoid of phenotypic consequences. OBJECTIVES To catalogue polymorphisms in azole and echinocandin resistance genes occurring in susceptible strains in order to rapidly pinpoint relevant mutations in resistant strains. METHODS Genome sequences from 151 unrelated C. albicans strains susceptible to fluconazole and caspofungin were used to create a catalogue of non-synonymous polymorphisms in genes involved in resistance to azoles (ERG11, TAC1, MRR1 and UPC2) or echinocandins (FKS1). The potential of this catalogue to reveal putative resistance mutations was tested in 10 azole-resistant isolates, including 1 intermediate to caspofungin. Selected mutations were analysed by mutagenesis experiments or mutational prediction effect. RESULTS In the susceptible strains, we identified 126 amino acid substitutions constituting the catalogue of phenotypically neutral polymorphisms. By excluding these neutral substitutions, we identified 22 additional substitutions in the 10 resistant strains. Among these substitutions, 10 had already been associated with resistance. The remaining 12 were in Tac1p (n = 6), Upc2p (n = 2) and Erg11p (n = 4). Four out of the six homozygous substitutions in Tac1p (H263Y, A790V, H839Y and P971S) conferred increases in azole MICs, while no effects were observed for those in Upc2p. Additionally, two homozygous substitutions (Y64H and P236S) had a predicted conformation effect on Erg11p. CONCLUSIONS By establishing a catalogue of neutral polymorphisms occurring in genes involved in resistance to antifungal drugs, we provide a useful resource for rapid identification of mutations possibly responsible for phenotypic resistance in C. albicans.
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Affiliation(s)
- Emilie Sitterlé
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC2019 INRA, Paris, France.,Université Paris Diderot, Sorbonne Paris Cité, Paris, France.,Unité de Parasitologie-Mycologie, Service de Microbiologie clinique, Hôpital Necker-Enfants-Malades, Assistance Publique des Hôpitaux de Paris (APHP), Paris, France
| | - Alix T Coste
- Institut de Microbiologie, Université de Lausanne et Centre Hospitalo-Universitaire, Lausanne, Switzerland
| | - Thomas Obadia
- Hub de Bioinformatique et Biostatistique, Département Biologie Computationnelle, Institut Pasteur, USR 3756 CNRS, Paris, France.,Unité Malaria: parasites et hôtes, Département Parasites et Insectes Vecteurs, Institut Pasteur, Paris, France
| | - Corinne Maufrais
- Hub de Bioinformatique et Biostatistique, Département Biologie Computationnelle, Institut Pasteur, USR 3756 CNRS, Paris, France
| | - Murielle Chauvel
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC2019 INRA, Paris, France
| | - Natacha Sertour
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC2019 INRA, Paris, France
| | - Dominique Sanglard
- Institut de Microbiologie, Université de Lausanne et Centre Hospitalo-Universitaire, Lausanne, Switzerland
| | - Anne Puel
- Laboratoire de génétique humaine des maladies infectieuses, Necker, INSERM U1163, Paris, France.,Université Paris Descartes, Institut Imagine, Paris, France
| | - Christophe D'Enfert
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC2019 INRA, Paris, France
| | - Marie-Elisabeth Bougnoux
- Unité Biologie et Pathogénicité Fongiques, Département de Mycologie, Institut Pasteur, USC2019 INRA, Paris, France.,Unité de Parasitologie-Mycologie, Service de Microbiologie clinique, Hôpital Necker-Enfants-Malades, Assistance Publique des Hôpitaux de Paris (APHP), Paris, France.,Université de Paris, Paris, France
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16
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Baltaci N, Kalkanci A. Demonstration of Mutation Development and Virulence Change in Reference Candida Strains Exposed to Caspofungin. Journal of Basic and Clinical Health Sciences. [DOI: 10.30621/jbachs.920675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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17
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Carolus H, Pierson S, Muñoz JF, Subotić A, Cruz RB, Cuomo CA, Van Dijck P. Genome-Wide Analysis of Experimentally Evolved Candida auris Reveals Multiple Novel Mechanisms of Multidrug Resistance. mBio 2021; 12:e03333-20. [PMID: 33820824 PMCID: PMC8092288 DOI: 10.1128/mbio.03333-20] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 02/12/2021] [Indexed: 12/12/2022] Open
Abstract
Candida auris is globally recognized as an opportunistic fungal pathogen of high concern, due to its extensive multidrug resistance (MDR). Still, molecular mechanisms of MDR are largely unexplored. This is the first account of genome-wide evolution of MDR in C. auris obtained through serial in vitro exposure to azoles, polyenes, and echinocandins. We show the stepwise accumulation of copy number variations and novel mutations in genes both known and unknown in antifungal drug resistance. Echinocandin resistance was accompanied by a codon deletion in FKS1 hot spot 1 and a substitution in FKS1 "novel" hot spot 3. Mutations in ERG3 and CIS2 further increased the echinocandin MIC. Decreased azole susceptibility was linked to a mutation in transcription factor TAC1b and overexpression of the drug efflux pump Cdr1, a segmental duplication of chromosome 1 containing ERG11, and a whole chromosome 5 duplication, which contains TAC1b The latter was associated with increased expression of ERG11, TAC1b, and CDR2 but not CDR1 The simultaneous emergence of nonsense mutations in ERG3 and ERG11 was shown to decrease amphotericin B susceptibility, accompanied with fluconazole cross-resistance. A mutation in MEC3, a gene mainly known for its role in DNA damage homeostasis, further increased the polyene MIC. Overall, this study shows the alarming potential for and diversity of MDR development in C. auris, even in a clade until now not associated with MDR (clade II), stressing its clinical importance and the urge for future research.IMPORTANCECandida auris is a recently discovered human fungal pathogen and has shown an alarming potential for developing multi- and pan-resistance toward all classes of antifungals most commonly used in the clinic. Currently, C. auris has been globally recognized as a nosocomial pathogen of high concern due to this evolutionary potential. So far, this is the first study in which the stepwise progression of multidrug resistance (MDR) in C. auris is monitored in vitro Multiple novel mutations in known resistance genes and genes previously not or vaguely associated with drug resistance reveal rapid MDR evolution in a C. auris clade II isolate. Additionally, this study shows that in vitro experimental evolution can be a powerful tool to discover new drug resistance mechanisms, although it has its limitations.
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Affiliation(s)
- Hans Carolus
- VIB Center for Microbiology, Leuven, Belgium
- Department of Biology, KU Leuven, Leuven, Belgium
| | | | - José F Muñoz
- Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA
| | - Ana Subotić
- VIB Center for Microbiology, Leuven, Belgium
- Department of Biology, KU Leuven, Leuven, Belgium
| | - Rita B Cruz
- Department of Biology, KU Leuven, Leuven, Belgium
| | | | - Patrick Van Dijck
- VIB Center for Microbiology, Leuven, Belgium
- Department of Biology, KU Leuven, Leuven, Belgium
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18
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Rosam K, Monk BC, Lackner M. Sterol 14α-Demethylase Ligand-Binding Pocket-Mediated Acquired and Intrinsic Azole Resistance in Fungal Pathogens. J Fungi (Basel) 2020; 7:jof7010001. [PMID: 33374996 PMCID: PMC7822023 DOI: 10.3390/jof7010001] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/17/2020] [Accepted: 12/18/2020] [Indexed: 12/17/2022] Open
Abstract
The fungal cytochrome P450 enzyme sterol 14α-demethylase (SDM) is a key enzyme in the ergosterol biosynthesis pathway. The binding of azoles to the active site of SDM results in a depletion of ergosterol, the accumulation of toxic intermediates and growth inhibition. The prevalence of azole-resistant strains and fungi is increasing in both agriculture and medicine. This can lead to major yield loss during food production and therapeutic failure in medical settings. Diverse mechanisms are responsible for azole resistance. They include amino acid (AA) substitutions in SDM and overexpression of SDM and/or efflux pumps. This review considers AA affecting the ligand-binding pocket of SDMs with a primary focus on substitutions that affect interactions between the active site and the substrate and inhibitory ligands. Some of these interactions are particularly important for the binding of short-tailed azoles (e.g., voriconazole). We highlight the occurrence throughout the fungal kingdom of some key AA substitutions. Elucidation of the role of these AAs and their substitutions may assist drug design in overcoming some common forms of innate and acquired azole resistance.
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Affiliation(s)
- Katharina Rosam
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Schöpfstrasse 41, 6020 Innsbruck, Austria;
| | - Brian C. Monk
- Sir John Walsh Research Institute and Department of Oral Biology, Faculty of Dentistry, University of Otago, PO Box 56, 9054 Dunedin, New Zealand;
| | - Michaela Lackner
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Schöpfstrasse 41, 6020 Innsbruck, Austria;
- Correspondence: ; Tel.: +43-512-003-70725
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19
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Fraser M, Borman AM, Thorn R, Lawrance LM. Resistance to echinocandin antifungal agents in the United Kingdom in clinical isolates of Candida glabrata: Fifteen years of interpretation and assessment. Med Mycol 2020; 58:219-226. [PMID: 31111912 DOI: 10.1093/mmy/myz053] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/02/2019] [Accepted: 04/24/2019] [Indexed: 01/08/2023] Open
Abstract
Candidemia is widely reported as the fourth most common form of bloodstream infection worldwide. Reports of breakthrough cases of candidemia are increasing, especially in the context of a move away from azole antifungals as prophylactic or first line treatment toward the use of echinocandin agents. The global evaluation of echinocandin antifungal susceptibility since 2003 has included switches in testing methodologies and the move to a sentinel echinocandin approach for classification reporting. This study compiles previously unpublished data from echinocandin susceptibility testing of UK clinical isolates of C. glabrata received at the Public Health England Mycology Reference Laboratory from 2003 to 2016 and reevaluates the prevalence of resistance in light of currently accepted testing protocols. From 2015 onward, FKS gene mutation detection using a novel Pyrosequencing® assay was assessed as a predictor of echinocandin resistance alongside conventional susceptibility testing. Overall, our data show that echinocandin resistance in UK isolates of C. glabrata is a rare phenomenon and prevalence has not appreciably increased in the last 14 years. The pyrosequencing assay was able to successfully detect hot spot mutations in FKS1 and FKS2, although not all isolates that exhibited phenotypic resistance demonstrated detectable hot spot mutations. We propose that a rapid genomic based detection method for FKS mutations, as part of a multifactorial approach to susceptibility testing, could help provide accurate and timely management decisions especially in regions where echinocandin resistance has been reported to be emerging in this important pathogen.
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Affiliation(s)
- Mark Fraser
- UK National Mycology Reference Laboratory, Public Health England, Bristol, UK.,Centre for Research in Bioscience, University of the West of England, Coldharbour Lane, Bristol, UK
| | - Andrew M Borman
- UK National Mycology Reference Laboratory, Public Health England, Bristol, UK
| | - Robin Thorn
- Centre for Research in Bioscience, University of the West of England, Coldharbour Lane, Bristol, UK
| | - Lynne M Lawrance
- Centre for Research in Bioscience, University of the West of England, Coldharbour Lane, Bristol, UK
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20
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Arendrup MC, Friberg N, Mares M, Kahlmeter G, Meletiadis J, Guinea J. How to interpret MICs of antifungal compounds according to the revised clinical breakpoints v. 10.0 European committee on antimicrobial susceptibility testing (EUCAST). Clin Microbiol Infect 2020; 26:1464-1472. [PMID: 32562861 DOI: 10.1016/j.cmi.2020.06.007] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 05/29/2020] [Accepted: 06/06/2020] [Indexed: 11/16/2022]
Abstract
BACKGROUND EUCAST has revised the definition of the susceptibility category I from 'Intermediate' to 'Susceptible, Increased exposure'. This implies that I can be used where the drug concentration at the site of infection is high, either because of dose escalation or through other means to ensure efficacy. Consequently, I is no longer used as a buffer zone to prevent technical factors from causing misclassifications and discrepancies in interpretations. Instead, an Area of Technical Uncertainty (ATU) has been introduced for MICs that cannot be categorized without additional information as a warning to the laboratory that decision on how to act has to be made. To implement these changes, the EUCAST-AFST (Subcommittee on Antifungal Susceptibility Testing) reviewed all, and revised some, clinical antifungal breakpoints. OBJECTIVES The aim was to present an overview of the current antifungal breakpoints and supporting evidence behind the changes. SOURCES This document is based on the ten recently updated EUCAST rationale documents, clinical breakpoint and breakpoint ECOFF documents. CONTENT The following breakpoints (in mg/L) have been revised or established for Candida species: micafungin against C. albicans (ATU = 0.03); amphotericin B (S ≤/> R = 1/1), fluconazole (S ≤/> R = 2/4), itraconazole (S ≤/> R = 0.06/0.06), posaconazole (S ≤/> R = 0.06/0.06) and voriconazole (S ≤/> R = 0.06/0.25) against C. dubliniensis; fluconazole against C. glabrata (S ≤/> R = 0.001/16); and anidulafungin (S ≤/> R = 4/4) and micafungin (S ≤/> R = 2/2) against C. parapsilosis. For Aspergillus, new or revised breakpoints include itraconazole (ATU = 2) and isavuconazole against A. flavus (S ≤/> R = 1/2, ATU = 2); amphotericin B (S ≤/> R = 1/1), isavuconazole (S ≤ /> R = 1/2, ATU = 2), itraconazole (S ≤/> R = 1/1, ATU = 2), posaconazole (ATU = 0.25) and voriconazole (S ≤/> R = 1/1, ATU = 2) against A. fumigatus; itraconazole (S ≤/> R = 1/1, ATU = 2) and voriconazole (S ≤/> R = 1/1, ATU = 2) against A. nidulans; amphotericin B against A. niger (S ≤/> R = 1/1); and itraconazole (S ≤/> R = 1/1, ATU = 2) and posaconazole (ATU = 0.25) against A. terreus. IMPLICATIONS EUCAST-AFST has released ten new documents summarizing existing and new breakpoints and MIC ranges for control strains. A failure to adopt the breakpoint changes may lead to misclassifications and suboptimal or inappropriate therapy of patients with fungal infections.
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Affiliation(s)
- M C Arendrup
- Unit of Mycology, Department of Microbiological Surveillance and Research, Statens Serum Institut, Copenhagen, Denmark; Department of Clinical Microbiology, University Hospital Rigshospitalet, Copenhagen, Denmark; Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
| | - N Friberg
- Division of Clinical Microbiology, Helsinki University Hospital, HUSLAB, Finland
| | - M Mares
- Laboratory of Antimicrobial Chemotherapy, Ion Ionescu de la Brad University, Iasi, Romania
| | - G Kahlmeter
- The EUCAST Development Laboratory, Clinical Microbiology, Växjö, Sweden
| | - J Meletiadis
- Clinical Microbiology Laboratory, Attikon University Hospital, National and Kapodistrian University of Athens, Athens, Greece; Department of Medical Microbiology and Infectious Diseases, Erasmus MC, Rotterdam, the Netherlands
| | - J Guinea
- Clinical Microbiology and Infectious Diseases Department, Hospital General Universitario Gregorio Marañón, Madrid, Spain; CIBER de enfermedades Respiratorias-CIBERES (CB06/06/0058), Madrid, Spain; Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
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21
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Howard KC, Dennis EK, Watt DS, Garneau-Tsodikova S. A comprehensive overview of the medicinal chemistry of antifungal drugs: perspectives and promise. Chem Soc Rev 2020; 49:2426-2480. [PMID: 32140691 DOI: 10.1039/c9cs00556k] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The emergence of new fungal pathogens makes the development of new antifungal drugs a medical imperative that in recent years motivates the talents of numerous investigators across the world. Understanding not only the structural families of these drugs but also their biological targets provides a rational means for evaluating the merits and selectivity of new agents for fungal pathogens and normal cells. An equally important aspect of modern antifungal drug development takes a balanced look at the problems of drug potency and drug resistance. The future development of new antifungal agents will rest with those who employ synthetic and semisynthetic methodology as well as natural product isolation to tackle these problems and with those who possess a clear understanding of fungal cell architecture and drug resistance mechanisms. This review endeavors to provide an introduction to a growing and increasingly important literature, including coverage of the new developments in medicinal chemistry since 2015, and also endeavors to spark the curiosity of investigators who might enter this fascinatingly complex fungal landscape.
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Affiliation(s)
- Kaitlind C Howard
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40536-0596, USA.
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22
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Navarro-Rodríguez P, Martin-Vicente A, López-Fernández L, Guarro J, Capilla J. Expression of ERG11 and efflux pump genes CDR1, CDR2 and SNQ2 in voriconazole susceptible and resistant Candida glabrata strains. Med Mycol 2020; 58:30-38. [DOI: 10.1093/mmy/myz014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 02/01/2019] [Accepted: 02/05/2019] [Indexed: 11/12/2022] Open
Abstract
AbstractCandida glabrata causes difficult to treat invasive candidiasis due to its antifungal resistance, mainly to azoles. The aim of the present work was to study the role of the genes ERG11, CDR1, CDR2, and SNQ2 on the resistance to voriconazole (VRC) in a set of C. glabrata strains with known in vitro and in vivo susceptibility to this drug. Eighteen clinical isolates of C. glabrata were exposed in vitro to VRC, and the expression of the cited genes was quantified by real time quantitative polymerase chain reaction (q-PCR). In addition, the ERG11 gene was amplified and sequenced to detect possible mutations. Ten synonymous mutations were found in 15 strains, two of them being reported for the first time; however, no amino acid changes were detected. ERG11 and CDR1 were the most expressed genes in all the strains tested, while the expression of CDR2 and SNQ2 was modest. Our results show that gene expression does not directly correlate with the VRC MIC. In addition, the expression profiles of ERG11 and efflux pump genes did not change consistently after exposure to VRC. Although individual analysis did not result in a clear correlation between MIC and gene expression, we did observe an increase in ERG11 and CDR1 expression in resistant strains. It is of interest that considering both in vitro and in vivo results, the slight increase in such gene expression correlates with the observed resistance to VRC.
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Affiliation(s)
- Patricia Navarro-Rodríguez
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, and Institut d’Investigació Sanitària Pere Virgili (IISPV), Universitat Rovira i Virgili, Reus, Tarragona, Spain
| | - Adela Martin-Vicente
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, and Institut d’Investigació Sanitària Pere Virgili (IISPV), Universitat Rovira i Virgili, Reus, Tarragona, Spain
| | - Loida López-Fernández
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, and Institut d’Investigació Sanitària Pere Virgili (IISPV), Universitat Rovira i Virgili, Reus, Tarragona, Spain
| | - Josep Guarro
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, and Institut d’Investigació Sanitària Pere Virgili (IISPV), Universitat Rovira i Virgili, Reus, Tarragona, Spain
| | - Javier Capilla
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, and Institut d’Investigació Sanitària Pere Virgili (IISPV), Universitat Rovira i Virgili, Reus, Tarragona, Spain
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24
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Kesarwani V, Kelly HG, Shankar M, Robinson KJ, Kent SJ, Traven A, Corrie SR. Characterization of Key Bio-Nano Interactions between Organosilica Nanoparticles and Candida albicans. ACS Appl Mater Interfaces 2019; 11:34676-34687. [PMID: 31483991 DOI: 10.1021/acsami.9b10853] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Nanoparticle-cell interactions between silica nanomaterials and mammalian cells have been investigated extensively in the context of drug delivery, diagnostics, and imaging. While there are also opportunities for applications in infectious disease, the interactions of silica nanoparticles with pathogenic microbes are relatively underexplored. To bridge this knowledge gap, here, we investigate the effects of organosilica nanoparticles of different sizes, concentrations, and surface coatings on surface association and viability of the major human fungal pathogen Candida albicans. We show that uncoated and PEGylated organosilica nanoparticles associate with C. albicans in a size and concentration-dependent manner, but on their own, do not elicit antifungal activity. The particles are also shown to associate with human white blood cells, in a similar trend as observed with C. albicans, and remain noncytotoxic toward neutrophils. Smaller particles are shown to have low association with C. albicans in comparison to other sized particles and their association with blood cells was also observed to be minimal. We further demonstrate that by chemically immobilizing the clinically important echinocandin class antifungal drug, caspofungin, to PEGylated nanoparticles, the cell-material interaction changes from benign to antifungal, inhibiting C. albicans growth when provided in high local concentration on a surface. Our study provides the foundation for defining how organosilica particles could be tailored for clinical applications against C. albicans. Possible future developments include designing biomaterials that could detect, prevent, or treat bloodstream C. albicans infections, which at present have very high patient mortality.
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Affiliation(s)
- Vidhishri Kesarwani
- Department of Chemical Engineering and ARC Centre of Excellence in Convergent Bio-Nano Science and Technology , Monash University , Clayton , Victoria 3800 , Australia
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute , Monash University , Clayton , Victoria 3800 , Australia
| | - Hannah G Kelly
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, and ARC Centre of Excellence in Convergent BioNano Science and Technology , The University of Melbourne , Melbourne , Victoria 3010 , Australia
| | - Madhu Shankar
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute , Monash University , Clayton , Victoria 3800 , Australia
| | - Kye J Robinson
- Department of Chemical Engineering and ARC Centre of Excellence in Convergent Bio-Nano Science and Technology , Monash University , Clayton , Victoria 3800 , Australia
| | - Stephen J Kent
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, and ARC Centre of Excellence in Convergent BioNano Science and Technology , The University of Melbourne , Melbourne , Victoria 3010 , Australia
| | - Ana Traven
- Infection and Immunity Program and the Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute , Monash University , Clayton , Victoria 3800 , Australia
| | - Simon R Corrie
- Department of Chemical Engineering and ARC Centre of Excellence in Convergent Bio-Nano Science and Technology , Monash University , Clayton , Victoria 3800 , Australia
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25
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Binder U, Aigner M, Risslegger B, Hörtnagl C, Lass-Flörl C, Lackner M. Minimal Inhibitory Concentration (MIC)-Phenomena in Candida albicans and Their Impact on the Diagnosis of Antifungal Resistance. J Fungi (Basel) 2019; 5:E83. [PMID: 31487830 DOI: 10.3390/jof5030083] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 08/30/2019] [Accepted: 09/02/2019] [Indexed: 02/07/2023] Open
Abstract
Antifungal susceptibility testing (AFST) of clinical isolates is a tool in routine diagnostics to facilitate decision making on optimal antifungal therapy. The minimal inhibitory concentration (MIC)-phenomena (trailing and paradoxical effects (PXE)) observed in AFST complicate the unambiguous and reproducible determination of MICs and the impact of these phenomena on in vivo outcome are not fully understood. We aimed to link the MIC-phenomena with in vivo treatment response using the alternative infection model Galleria mellonella. We found that Candida albicans strains exhibiting PXE for caspofungin (CAS) had variable treatment outcomes in the Galleria model. In contrast, C. albicans strains showing trailing for voriconazole failed to respond in vivo. Caspofungin- and voriconazole-susceptible C. albicans strains responded to the respective antifungal therapy in vivo. In conclusion, MIC data and subsequent susceptibility interpretation of strains exhibiting PXE and/or trailing should be carried out with caution, as both effects are linked to drug adaptation and treatment response is uncertain to predict.
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26
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Toutounji M, Tokajian S, Khalaf RA. Genotypic and phenotypic characterization of Candida albicans Lebanese hospital isolates resistant and sensitive to caspofungin. Fungal Genet Biol 2019; 127:12-22. [DOI: 10.1016/j.fgb.2019.02.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 02/11/2019] [Accepted: 02/18/2019] [Indexed: 12/11/2022]
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Taj-Aldeen SJ, Salah H, Perez WB, Almaslamani M, Motyl M, AbdulWahab A, Healey KR, Perlin DS. Molecular Analysis of Resistance and Detection of Non-Wild-Type Strains Using Etest Epidemiological Cutoff Values for Amphotericin B and Echinocandins for Bloodstream Candida Infections from a Tertiary Hospital in Qatar. Antimicrob Agents Chemother 2018; 62:e00214-18. [PMID: 29941644 DOI: 10.1128/AAC.00214-18] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 06/05/2018] [Indexed: 11/20/2022] Open
Abstract
A total of 301 Candida bloodstream isolates collected from 289 patients over 5 years at a tertiary hospital in Qatar were evaluated. Out of all Candida infections, 53% were diagnosed in patients admitted to the intensive care units. Steady increases in non-albicans Candida species were reported from 2009 to 2014 (30.2% for Candida albicans versus 69.8% for the other Candida species). Etest antifungal susceptibility testing was performed on all recovered clinical isolates to determine echinocandin (micafungin and anidulafungin) and amphotericin B susceptibilities and assess non-wild-type (non-WT) strains (strains for which MICs were above the epidemiological cutoff values). DNA sequence analysis was performed on all isolates to assess the presence of FKS mutations, which confer echinocandin resistance in Candida species. A total of 3.9% of isolates (12/301) among strains of C. albicans and C. orthopsilosis contained FKS hot spot mutations, including heterozygous mutations in FKS1 For C. tropicalis, the Etest appeared to overestimate strains non-WT for micafungin, anidulafungin, and amphotericin B, as 14%, 11%, and 35% of strains, respectively, had values above the epidemiological cutoff value. However, no FKS mutations were identified in this species. For all other species, micafungin best reported the echinocandin non-WT strains relative to the FKS genotype, as anidulafungin tended to overestimate non-wild-type strains. Besides C. tropicalis, few strains were classified as non-WT for amphotericin B.
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Bader JC, Lakota EA, Flanagan S, Ong V, Sandison T, Rubino CM, Bhavnani SM, Ambrose PG. Overcoming the Resistance Hurdle: Pharmacokinetic-Pharmacodynamic Target Attainment Analyses for Rezafungin (CD101) against Candida albicans and Candida glabrata. Antimicrob Agents Chemother 2018; 62:e02614-17. [PMID: 29555634 PMCID: PMC5971579 DOI: 10.1128/aac.02614-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 03/07/2018] [Indexed: 01/05/2023] Open
Abstract
Rezafungin (CD101) is a novel echinocandin antifungal agent with activity against Aspergillus and Candida species, including azole- and echinocandin-resistant isolates. The objective of these analyses was to conduct pharmacokinetic (PK)-pharmacodynamic (PD) target attainment analyses to evaluate single and once-weekly rezafungin dosing to provide dose selection support for future clinical studies. Using a previously developed rezafungin population PK model, Monte Carlo simulations were conducted utilizing the following three intravenous rezafungin regimens: (i) a single 400 mg dose, (ii) 400 mg for week 1 followed by 200 mg weekly for 5 weeks, and (iii) 400 mg weekly for 6 weeks. Percent probabilities of achieving the nonclinical PK-PD targets associated with net fungal stasis and 1-log10 CFU reductions from baseline for Candida albicans and Candida glabrata were calculated for each rezafungin regimen. At the MIC90 for C. albicans and C. glabrata, a single 400 mg dose of rezafungin achieved probabilities of PK-PD target attainment of ≥90% through week 3 of therapy for all PK-PD targets evaluated. When evaluating the multiple-dose (i.e., weekly) regimens under these conditions, percent probabilities of PK-PD target attainment of 100% were achieved through week 6. Moreover, high (>90%) probabilities of PK-PD target attainment were achieved through week 6 following administration of the weekly regimens at or above the MIC100 values for C. albicans and C. glabrata based on contemporary in vitro surveillance data. These analyses support the use of single and once-weekly rezafungin regimens for the treatment of patients with candidemia and/or candidiasis due to C. albicans or C. glabrata.
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Affiliation(s)
- Justin C Bader
- Institute for Clinical Pharmacodynamics, Inc., Schenectady, New York, USA
| | - Elizabeth A Lakota
- Institute for Clinical Pharmacodynamics, Inc., Schenectady, New York, USA
| | | | - Voon Ong
- Cidara Therapeutics, San Diego, California, USA
| | | | | | - Sujata M Bhavnani
- Institute for Clinical Pharmacodynamics, Inc., Schenectady, New York, USA
| | - Paul G Ambrose
- Institute for Clinical Pharmacodynamics, Inc., Schenectady, New York, USA
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Martinez-Rossi NM, Bitencourt TA, Peres NTA, Lang EAS, Gomes EV, Quaresemin NR, Martins MP, Lopes L, Rossi A. Dermatophyte Resistance to Antifungal Drugs: Mechanisms and Prospectus. Front Microbiol 2018; 9:1108. [PMID: 29896175 PMCID: PMC5986900 DOI: 10.3389/fmicb.2018.01108] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 05/09/2018] [Indexed: 12/24/2022] Open
Abstract
Dermatophytes comprise pathogenic fungi that have a high affinity for the keratinized structures present in nails, skin, and hair, causing superficial infections known as dermatophytosis. A reasonable number of antifungal drugs currently exist on the pharmaceutical market to control mycoses; however, their cellular targets are restricted, and fungi may exhibit tolerance or resistance to these agents. For example, the stress caused by antifungal and cytotoxic drugs in sub-inhibitory concentrations promotes compensatory stress responses, with the over-expression of genes involved in cellular detoxification, drug efflux, and signaling pathways being among the various mechanisms that may contribute to drug tolerance. In addition, the ATP-binding cassette transporters in dermatophytes that are responsible for cellular efflux can act synergistically, allowing one to compensate for the absence of the other, revealing the complexity of drug tolerance phenomena. Moreover, mutations in genes coding for target enzymes could lead to substitutions in amino acids involved in the binding of antifungal agents, hindering their performance and leading to treatment failure. The relevance of each one of these mechanisms of resistance to fungal survival is hard to define, mainly because they can act simultaneously in the cell. However, an understanding of the molecular mechanisms involved in the resistance/tolerance processes, the identification of new antifungal targets, as well as the prospective of new antifungal compounds among natural or synthetic products, are expected to bring advances and new insights that facilitate the improvement or development of novel strategies for antifungal therapy.
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Affiliation(s)
- Nilce M Martinez-Rossi
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Tamires A Bitencourt
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Nalu T A Peres
- Department of Morphology, Federal University of Sergipe, Aracaju, Brazil
| | - Elza A S Lang
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Eriston V Gomes
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Natalia R Quaresemin
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Maíra P Martins
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Lucia Lopes
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Antonio Rossi
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
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Marcos-Zambrano LJ, Gómez-Perosanz M, Escribano P, Bouza E, Guinea J. The novel oral glucan synthase inhibitor SCY-078 shows in vitro activity against sessile and planktonic Candida spp. J Antimicrob Chemother 2018; 72:1969-1976. [PMID: 28175309 DOI: 10.1093/jac/dkx010] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 01/04/2017] [Indexed: 11/13/2022] Open
Abstract
Objectives We studied the antifungal activity of SCY-078 (an orally bioavailable 1,3-β -d- glucan synthesis inhibitor), micafungin and fluconazole against the planktonic and sessile forms of 178 Candida and non- Candida isolates causing fungaemia in patients recently admitted to a large European hospital. Methods The in vitro activity of SCY-078, micafungin and fluconazole against the planktonic form of the isolates was assessed using EUCAST EDef 7.3 and CLSI M27-A3. Antibiofilm activity was assessed using the XTT reduction assay. Results SCY-078 and micafungin showed potent in vitro activity against Candida and non- Candida isolates. The in vitro activity of both drugs was similar, but SYC-078 displayed significantly lower MIC values than micafungin against Candida parapsilosis and non- Candida isolates, whereas micafungin displayed significantly lower MIC values for the remaining species ( P <0.001). In contrast, SCY-078 and micafungin showed essentially the same activity against the biofilms with the exception of Candida glabrata , in which the micafungin sessile MIC values were significantly lower ( P <0.001). These observations were confirmed by assessing biofilm structure by scanning electron microscopy after antifungal treatment. Conclusions Our study showed that the high in vitro activity of SCY-078 against invasive Candida isolates in both sessile and planktonic forms is comparable to that of micafungin.
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Affiliation(s)
- Laura Judith Marcos-Zambrano
- Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Marta Gómez-Perosanz
- Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
| | - Pilar Escribano
- Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, Madrid, Spain.,Instituto de Investigación Sanitaria Gregorio Marañón, Madrid, Spain
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Dadar M, Tiwari R, Karthik K, Chakraborty S, Shahali Y, Dhama K. Candida albicans - Biology, molecular characterization, pathogenicity, and advances in diagnosis and control – An update. Microb Pathog 2018; 117:128-38. [DOI: 10.1016/j.micpath.2018.02.028] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 02/04/2018] [Accepted: 02/13/2018] [Indexed: 12/16/2022]
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32
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Yue Q, Li Y, Chen L, Zhang X, Liu X, An Z, Bills GF. Genomics-driven discovery of a novel self-resistance mechanism in the echinocandin-producing fungus Pezicula radicicola. Environ Microbiol 2018. [PMID: 29528534 DOI: 10.1111/1462-2920.14089] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The echinocandins are antifungal lipopeptides targeting fungi via noncompetitive inhibition of the β-1,3-d-glucan synthase FKS1 subunit. A novel echinocandin resistance mechanism involving an auxiliary copy of FKS1 in echinocandin-producing fungus Pezicula radicicola NRRL 12192 was discovered. We sequenced the genome of NRRL 12192 and predicted two FKS1-encoding genes (prfks1n and prfks1a), rather than a single FKS1 gene typical of filamentous ascomycetes. The prfks1a gene sits immediately adjacent to an echinocandin (sporiofungin) gene cluster, which was confirmed by disruption of prnrps4 and abolishment of sporiofungin production. Disruption of prfks1a dramatically increased the strain's sensitivity to exogenous echinocandins. In the absence of echinocandins, transcription levels of prfks1a relative to β-tubulin in the wild type and in Δprnrps4 stains were similar. Moreover, prfks1a is consistently transcribed at low levels and is upregulated in the presence of exogenous echinocandin, but not during growth conditions promoting endogenous production of sporiofungin. Therefore, we conclude that prfks1a is primarily responsible for protecting the fungus against extracellular echinocandin toxicity. The presence of unclustered auxiliary copies of FKS1 with high similarity to prfks1a in two other echinocandin-producing strains suggests that this previously unrecognized resistance mechanism may be common in echinocandin-producing fungi of the family Dermataceae of the class Leotiomycetes.
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Affiliation(s)
- Qun Yue
- Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA.,Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Yan Li
- Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA.,Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China
| | - Li Chen
- Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Xiaoling Zhang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Xingzhong Liu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, People's Republic of China
| | - Zhiqiang An
- Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Gerald F Bills
- Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, University of Texas Health Science Center at Houston, Houston, TX, USA
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33
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Salci TP, Negri M, Abadio AKR, Svidzinski TIE, Kioshima ÉS. Targeting Candida spp. to develop antifungal agents. Drug Discov Today 2018; 23:802-14. [PMID: 29353694 DOI: 10.1016/j.drudis.2018.01.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 12/09/2017] [Accepted: 01/04/2018] [Indexed: 01/15/2023]
Abstract
Invasive fungal infections are a complex challenge throughout the world because of their high incidence, mainly in critically ill patients, and high mortality rates. The antifungal agents currently available are limited; thus, there is a need for the rapid development of new drugs. In silico methods are a modern strategy to explore interactions between new compounds and specific fungal targets, but they depend on precise genetic information. Here, we discuss the main Candida spp. target genes, including information about null mutants, virulence, cytolocalization, co-regulatory genes, and compounds that are related to protein expression. These data will provide a basis for the future in silico development of antifungal drugs.
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34
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Perlin DS, Wiederhold NP. Culture-Independent Molecular Methods for Detection of Antifungal Resistance Mechanisms and Fungal Identification. J Infect Dis 2017; 216:S458-S465. [PMID: 28911041 DOI: 10.1093/infdis/jix121] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Resistance to azoles and echinocandins has emerged as a significant factor affecting the clinical management of patients with invasive fungal infections. Immunosuppressed patients at high risk for invasive fungal infections often have prolonged or repeated exposure to antifungals resulting in either the well-documented selection of naturally occurring, less susceptible fungal species, or the in situ development of specific resistance mechanisms. Nucleic acid-based molecular diagnostics are particularly well suited for the rapid detection of low-abundance fungal pathogens and identification of the infecting pathogen to the genus and species levels, as well as assessment of resistance mechanisms. A wide range of molecular probing technologies involving real-time polymerase chain reaction (PCR) assays that facilitate direct analysis of a single infecting genome in a sterile blood specimen are available and have recently been commercialized (eg, Roche LightCycler SeptiFast and T2 Biosystems T2Candida). One of the exciting applications of molecular technology is the direct detection of specific resistance mechanisms that evolve during therapy. In principle, the detection of resistance mechanisms that have been independently validated to cause resistance provides a culture-independent biomarker for potential therapeutic failure. The emergence of real-time PCR assays utilizing allele-specific molecular detection technology that is highly sensitive, robust, and high-throughput has the potential to improve patient care by providing faster detection of drug-resistant infecting strains and to help inform therapeutic management.
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Affiliation(s)
- David S Perlin
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, Newark, New Jersey
| | - Nathan P Wiederhold
- Fungus Testing Laboratory, University of Texas Health Science Center, San Antonio
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35
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Abstract
Invasive Candida infections remain an important cause of morbidity and mortality, especially in hospitalized and immunocompromised or critically ill patients. A limited number of antifungal agents from only a few drug classes are available to treat patients with these serious infections. Resistance can be either intrinsic or acquired. Resistance mechanisms are not exchanged between Candida; thus, acquired resistance either emerges in response to an antifungal selection pressure in the individual patient or, more rarely, occur due to horizontal transmission of resistant strains between patients. Although multidrug resistance is uncommon, increasing reports of multidrug resistance to the azoles, echinocandins, and polyenes have occurred in several Candida species, most notably Candida glabrata and more recently Candida auris. Drivers are overall antifungal use, subtherapeutic drug levels at sites of infection/colonization, drug sequestration in the biofilm matrix, and, in the setting of outbreaks, suboptimal infection control. Moreover, recent research suggests that DNA mismatch repair gene mutations may facilitate acquisition of resistance mutations in C. glabrata specifically. Diagnosis of antifungal-resistant Candida infections is critical to the successful management of patients with these infections. Reduction of unnecessary use of antifungals via antifungal stewardship is critical to limit multidrug resistance emergence.
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Affiliation(s)
- Maiken Cavling Arendrup
- Unit of Mycology, Statens Serum Institut.,Department of Clinical Microbiology, Rigshospitalet.,Department of Clinical Medicine, University of Copenhagen, Denmark
| | - Thomas F Patterson
- Division of Infectious Diseases, San Antonio Center for Medical Mycology, UT Health San Antonio, and the South Texas Veterans Health Care System
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36
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Xisto MIDS, Caramalho RDF, Rocha DAS, Ferreira-Pereira A, Sartori B, Barreto-Bergter E, Junqueira ML, Lass-Flörl C, Lackner M. Pan-azole-resistant Candida tropicalis carrying homozygous erg11 mutations at position K143R: a new emerging superbug? J Antimicrob Chemother 2017; 72:988-992. [PMID: 28065893 DOI: 10.1093/jac/dkw558] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 11/28/2016] [Indexed: 11/14/2022] Open
Abstract
Objectives Candidaemia is a public health problem mainly in hospitalized individuals worldwide. In Brazil, Candida albicans is the most prevalent species that causes candidaemia, followed by Candida tropicalis and Candida parapsilosis . Few data on the abundance of antifungal resistance are available for Latin America. Methods We analysed the frequency of azole and echinocandin resistance in Candida isolates ( n = 75) collected between 2012 and 2014 at the University Hospital of Federal University of Juiz de Fora (Brazil). The primary targets erg11 (azoles) and fks1 (echinocandins) were sequenced and modelled at the protein level. Antifungal susceptibility testing was performed according to CLSI (M27-A3 and M27-S4) and according to EUCAST. Results The three most frequent species were C. albicans (38.0%), C. tropicalis (30.0%) and Candida glabrata (17.0%). Azole resistance was observed in 27.0% of all Candida isolates, while 20.0% of all isolates were echinocandin resistant. A novel mutation in erg11 at location K143R was found to be associated with phenotypically pan-azole-resistant C. tropicalis isolates. This mutation maps near the active binding site of erg11 and is likely to confer pan-azole resistance to C. tropicalis . Conclusions A novel point mutation (K143R) located in the erg11 gene of C. tropicalis was found in pan-azole-resistant strains. According to our protein homology model, it is very likely that the mutation K143R causes pan-azole resistance in C. tropicalis . Moreover, an up-regulation of ABC transporters was observed, which can add up to a pan-azole-resistant phenotype.
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Affiliation(s)
- Mariana I D S Xisto
- Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Innsbruck, Austria.,Laboratório de Química Biológica de Microorganismos, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rita D F Caramalho
- Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Innsbruck, Austria
| | - Débora A S Rocha
- Laboratório de Bioquímica Microbiana, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Antonio Ferreira-Pereira
- Laboratório de Bioquímica Microbiana, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Bettina Sartori
- Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Innsbruck, Austria
| | - Eliana Barreto-Bergter
- Laboratório de Química Biológica de Microorganismos, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Maria L Junqueira
- Hospital Universitário, Universidade Federal de Juiz de Fora, Minas Gerais, Brazil
| | - Cornelia Lass-Flörl
- Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Innsbruck, Austria
| | - Michaela Lackner
- Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Innsbruck, Austria
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Abstract
Abstract
Objectives
Echinocandins are the newest addition of the last decade to the antifungal armamentarium, which, owing to their unique mechanism of action, selectively target the fungal cells without affecting mammalian cells. Since the time of their introduction, they have come to occupy an important niche in the antifungal pharmacotherapy, due to their efficacy, safety, tolerability and favourable pharmacokinetic profiles. This review deals with the varying facets of echinocandins such as their chemistry, in-vitro and in-vivo evaluations, clinical utility and indications, pharmacokinetic and pharmacodynamic profiles, and pharmacoeconomic considerations.
Key findings
Clinical studies have demonstrated that the echinocandins – caspofungin, micafungin and anidulafungin – are equivalent, if not superior, to the mainstay antifungal therapies involving amphotericin B and fluconazole. Moreover, echinocandin regimen has been shown to be more cost-effective and economical. Hence, the echinocandins have found favour in the management of invasive systemic fungal infections.
Conclusions
The subtle differences in echinocandins with respect to their pharmacology, clinical therapy and the mechanisms of resistance are emerging at a rapid pace from the current pool of research which could potentially aid in extending their utility in the fungal infections of the eye, heart and nervous system.
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Affiliation(s)
- Akash Patil
- Department of Pharmaceutics and Drug Delivery, School of Pharmacy, University of Mississippi, Oxford, MS, USA
| | - Soumyajit Majumdar
- Department of Pharmaceutics and Drug Delivery, School of Pharmacy, University of Mississippi, Oxford, MS, USA
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Grosset M, Desnos-Ollivier M, Godet C, Kauffmann-Lacroix C, Cazenave-Roblot F. Recurrent episodes of Candidemia due to Candida glabrata, Candida tropicalis and Candida albicans with acquired echinocandin resistance. Med Mycol Case Rep 2016; 14:20-23. [PMID: 27995055 PMCID: PMC5155041 DOI: 10.1016/j.mmcr.2016.12.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 12/03/2016] [Accepted: 12/06/2016] [Indexed: 11/17/2022] Open
Abstract
Mixed fungal infection and acquired echinocandin resistance of Candida spp. remain infrequent. In this study we have reported the case of a patient hospitalized for tuberculosis who experienced multiple infections due to three common Candida species (C. albicans, C. glabrata, C. tropicalis). Furthermore, consecutive isolates from blood cultures and heart valve were found resistant to azoles (C. tropicalis) and to echinocandin with either novel (C. tropicalis) or previously described (C. albicans) missense mutations in the Fks gene.
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Affiliation(s)
- Marine Grosset
- Service de Maladies Infectieuses et tropicales, CHU de Poitiers, 2 rue de la Milétrie, Poitiers 86021, France
| | - Marie Desnos-Ollivier
- Institut Pasteur, Unité de Mycologie Moléculaire, Centre National de Référence Mycologie et Antifongiques, 25 rue du Dr Roux, Paris 75015, France
| | - Cendrine Godet
- Service de Maladies Infectieuses et tropicales, CHU de Poitiers, 2 rue de la Milétrie, Poitiers 86021, France
| | | | - France Cazenave-Roblot
- Service de Maladies Infectieuses et tropicales, CHU de Poitiers, 2 rue de la Milétrie, Poitiers 86021, France
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Davidson R, Pontasch JA, Wu JQ. Sbg1 Is a Novel Regulator for the Localization of the β-Glucan Synthase Bgs1 in Fission Yeast. PLoS One 2016; 11:e0167043. [PMID: 27898700 PMCID: PMC5127554 DOI: 10.1371/journal.pone.0167043] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 11/08/2016] [Indexed: 02/03/2023] Open
Abstract
Glucan synthases synthesize glucans, complex polysaccharides that are the major components in fungal cell walls and division septa. Studying regulation of glucan synthases is important as they are essential for fungal cell survival and thus popular targets for anti-fungal drugs. Linear 1,3-β-glucan is the main component of primary septum and is synthesized by the conserved β-glucan synthase Bgs1 in fission yeast cytokinesis. It is known that Rho1 GTPase regulates Bgs1 catalytic activity and the F-BAR protein Cdc15 plays a role in Bgs1 delivery to the plasma membrane. Here we characterize a novel protein Sbg1 that is present in a complex with Bgs1 and regulates its protein levels and localization. Sbg1 is essential for contractile-ring constriction and septum formation during cytokinesis. Sbg1 and Bgs1 physically interact and are interdependent for localization to the plasma membrane. Bgs1 is less stable and/or mis-targeted to vacuoles in sbg1 mutants. Moreover, Sbg1 plays an earlier and more important role in Bgs1 trafficking and localization than Cdc15. Together, our data reveal a new mode of regulation for the essential β-glucan synthase Bgs1 by the novel protein Sbg1.
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Affiliation(s)
- Reshma Davidson
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
| | - Josef A. Pontasch
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
| | - Jian-Qiu Wu
- Department of Molecular Genetics, The Ohio State University, Columbus, Ohio, United States of America
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
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40
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Abstract
The echinocandins are important agents for the treatment of invasive fungal infections, especially those caused by Candida species. However, as with other antimicrobial agents, microbiologic resistance to this class of antifungal agents has emerged and can result in clinical failure. Several studies have recently reported an increase in echinocandin resistance in Candida glabrata isolates at various medical centers in different geographic regions of the USA. Recent studies have also reported that many of these isolates may also be fluconazole resistant, leaving few treatment options available for clinicians to use in patients with invasive candidiasis caused by this species. Our understanding of the clinical relevance of specific point mutations within the FKS genes that cause echinocandin resistance and risk factors for the development of microbiologic resistance and clinical failure have also increased. The purpose of this review is to discuss echinocandin resistance in Candida species and recent reports that have increased our understanding of this growing clinical problem.
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Affiliation(s)
- Nathan P Wiederhold
- Department of Pathology, Fungus Testing Laboratory, University of Texas Health Science Center at San Antonio, 7703 Floyd Curl Drive, San Antonio, TX, 78229, USA.
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41
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Abstract
PURPOSE OF REVIEW We review and offer our clinical perspectives on the emergence of echinocandin-resistant Candida. RECENT FINDINGS Candida FKS gene mutations attenuate echinocandin activity, but overall mutation rates among clinical isolates remain low (Candida glabrata, ∼4%; other species, <1%). Rates are higher with prior echinocandin exposure, exceeding 50% among C. glabrata or Candida albicans isolates causing breakthrough invasive candidiasis. The median duration of prior echinocandin exposure among FKS mutant isolates is ∼100 days. The clinical usefulness of echinocandin susceptibility testing is limited by the low overall prevalence of resistance, and uncertainties surrounding testing methods and interpretation of minimum inhibitory concentrations (MICs). In single-center studies, caspofungin resistance (defined using institution-specific MIC breakpoints) was 32-53% sensitive and 75-95% specific for predicting treatment outcomes of C. glabrata invasive candidiasis; corresponding values for the presence of an FKS mutation were 35-41% and 90-98%. Results were similar using anidulafungin and micafungin MICs. Clinical data are scarce for non-C. glabrata species. SUMMARY Echinocandins remain preferred agents against invasive Candida infections. Susceptibility testing and FKS genotypic testing do not have roles in routine clinical practice, but may be useful in newly-diagnosed patients who are echinocandin-experienced or those who have not responded to echinocandin treatment.
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Liu Y, Lee IJ, Sun M, Lower CA, Runge KW, Ma J, Wu JQ. Roles of the novel coiled-coil protein Rng10 in septum formation during fission yeast cytokinesis. Mol Biol Cell 2016; 27:2528-41. [PMID: 27385337 PMCID: PMC4985255 DOI: 10.1091/mbc.e16-03-0156] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 06/21/2016] [Indexed: 12/31/2022] Open
Abstract
The regulation of Rho-GAP localization is not well understood. A novel coiled-coil protein Rng10 is characterized that localizes the Rho-GAP Rga7 in fission yeast. Rng10 and Rga7 physically interact and work together to regulate the accumulation and dynamics of glucan synthases for successful septum formation during cytokinesis. Rho GAPs are important regulators of Rho GTPases, which are involved in various steps of cytokinesis and other processes. However, regulation of Rho-GAP cellular localization and function is not fully understood. Here we report the characterization of a novel coiled-coil protein Rng10 and its relationship with the Rho-GAP Rga7 in fission yeast. Both rng10Δ and rga7Δ result in defective septum and cell lysis during cytokinesis. Rng10 and Rga7 colocalize on the plasma membrane at the cell tips during interphase and at the division site during cell division. Rng10 physically interacts with Rga7 in affinity purification and coimmunoprecipitation. Of interest, Rga7 localization is nearly abolished without Rng10. Moreover, Rng10 and Rga7 work together to regulate the accumulation and dynamics of glucan synthases for successful septum formation in cytokinesis. Our results show that cellular localization and function of the Rho-GAP Rga7 are regulated by a novel protein, Rng10, during cytokinesis in fission yeast.
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Affiliation(s)
- Yajun Liu
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - I-Ju Lee
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Mingzhai Sun
- Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210
| | - Casey A Lower
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210
| | - Kurt W Runge
- Department of Molecular Genetics, Cleveland Clinic Lerner College of Medicine, Cleveland, OH 44195
| | - Jianjie Ma
- Department of Surgery, Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH 43210
| | - Jian-Qiu Wu
- Department of Molecular Genetics, The Ohio State University, Columbus, OH 43210 Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH 43210
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Sanguinetti M, Posteraro B, Lass-Flörl C. Antifungal drug resistance among Candida species: mechanisms and clinical impact. Mycoses 2016; 58 Suppl 2:2-13. [PMID: 26033251 DOI: 10.1111/myc.12330] [Citation(s) in RCA: 254] [Impact Index Per Article: 31.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 03/23/2015] [Indexed: 11/29/2022]
Abstract
The epidemiology of Candida infections has changed in recent years. Although Candida albicans is still the main cause of invasive candidiasis in most clinical settings, a substantial proportion of patients is now infected with non-albicans Candida species. The various Candida species vary in their susceptibility to the most commonly used antifungal agents, and the intrinsic resistance to antifungal therapy seen in some species, along with the development of acquired resistance during treatment in others, is becoming a major problem in the management of Candida infection. A better understanding of the mechanisms and clinical impact of antifungal drug resistance is essential for the efficient treatment of patients with Candida infection and for improving treatment outcomes. Herein, we report resistance to the azoles and echinocandins among Candida species.
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Affiliation(s)
| | - Brunella Posteraro
- Institute of Public Health, Section of Hygiene, Università Cattolica del Sacro Cuore, Rome, Italy
| | - Cornelia Lass-Flörl
- Division of Hygiene and Medical Microbiology, Innsbruck Medical University, Innsbruck, Austria
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Abstract
Rapid, accurate diagnostic laboratory tests are needed to improve clinical outcomes of invasive fungal disease (IFD). Traditional direct microscopy, culture and histological techniques constitute the 'gold standard' against which newer tests are judged. Molecular diagnostic methods, whether broad-range or fungal-specific, have great potential to enhance sensitivity and speed of IFD diagnosis, but have varying specificities. The use of PCR-based assays, DNA sequencing, and other molecular methods including those incorporating proteomic approaches such as matrix-assisted laser desorption ionisation-time of flight mass spectroscopy (MALDI-TOF MS) have shown promising results. These are used mainly to complement conventional methods since they require standardisation before widespread implementation can be recommended. None are incorporated into diagnostic criteria for defining IFD. Commercial assays may assist standardisation. This review provides an update of molecular-based diagnostic approaches applicable to biological specimens and fungal cultures in microbiology laboratories. We focus on the most common pathogens, Candida and Aspergillus, and the mucormycetes. The position of molecular-based approaches in the detection of azole and echinocandin antifungal resistance is also discussed.
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Abstract
Fungal infections due to Candida and Aspergillus species cause extensive morbidity and mortality, especially among immunosuppressed patients, and antifungal therapy is critical to patient management. Yet only a few drug classes are available to treat invasive fungal diseases, and this problem is compounded by the emergence of antifungal resistance. Echinocandin drugs are the preferred choice to treat candidiasis. They are the first cell wall-active agents and target the fungal-specific enzyme glucan synthase, which catalyzes the biosynthesis of β-1,3-glucan, a key cell wall polymer. Therapeutic failures occur rarely among common Candida species, with the exception of Candida glabrata, which is frequently multidrug resistant. Echinocandin resistance in susceptible species is always acquired during therapy. The mechanism of resistance involves amino acid changes in hot-spot regions of Fks subunits of glucan synthase, which decrease the sensitivity of the enzyme to drug. Cellular stress response pathways lead to drug adaptation, which promotes the formation of resistant fks strains. Clinical factors promoting echinocandin resistance include empiric therapy, prophylaxis, gastrointestinal reservoirs, and intra-abdominal infections. A better understanding of the echinocandin-resistance mechanism, along with cellular and clinical factors promoting resistance, will facilitate more effective strategies to overcome and prevent echinocandin resistance.
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Affiliation(s)
- David S Perlin
- New Jersey Medical School, Rutgers Biomedical and Health Sciences, Public Health Research Institute, Newark, New Jersey
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Lackner M, Binder U, Reindl M, Gönül B, Fankhauser H, Mair C, Nagl M. N-Chlorotaurine Exhibits Fungicidal Activity against Therapy-Refractory Scedosporium Species and Lomentospora prolificans. Antimicrob Agents Chemother 2015; 59:6454-62. [PMID: 26239996 DOI: 10.1128/AAC.00957-15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 07/24/2015] [Indexed: 01/26/2023] Open
Abstract
N-Chlorotaurine (NCT), a well-tolerated endogenous long-lived oxidant that can be applied topically as an antiseptic, was tested on its fungicidal activity against Scedosporium and Lomentospora, opportunistic fungi that cause severe infections with limited treatment options, mainly in immunocompromised patients. In quantitative killing assays, both hyphae and conidia of Scedosporium apiospermum, Scedosporium boydii, and Lomentospora prolificans (formerly Scedosporium prolificans) were killed by 55 mM (1.0%) NCT at pH 7.1 and 37°C, with a 1- to 4-log10 reduction in CFU after 4 h and a 4- to >6-log10 reduction after 24 h. The addition of ammonium chloride to NCT markedly increased this activity. LIVE/DEAD staining of conidia treated with 1.0% NCT for 0.5 to 3 h increased the permeability of the cell wall and membrane. Preincubation of the test fungi in 1.0% NCT for 10 to 60 min delayed the time to germination of conidia by 2 h to >12 h and reduced their germination rate by 10.0 to 100.0%. Larvae of Galleria mellonella infected with 1.0 × 10(7) conidia of S. apiospermum and S. boydii died at a rate of 90.0 to 100% after 8 to 12 days. The mortality rate was reduced to 20 to 50.0% if conidia were preincubated in 1.0% NCT for 0.5 h or if heat-inactivated conidia were used. Our study demonstrates the fungicidal activity of NCT against different Scedosporium and Lomentospora species. A postantifungal effect connected with a loss of virulence occurs after sublethal incubation times. The augmenting effect of ammonium chloride can be explained by the formation of monochloramine.
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Abstract
PURPOSE OF REVIEW Echinocandin resistance in Candida is a great concern, as the echinocandin drugs are recommended as first-line therapy for patients with invasive candidiasis. Here, we review recent advances in our understanding of the epidemiology, underlying mechanisms, methods for detection and clinical implications. RECENT FINDINGS Echinocandin resistance has emerged over the recent years. It has been found in most clinically relevant Candida spp., but is most common in C. glabrata with rates exceeding 10% at selected institutions. It is most commonly detected after 3-4 weeks of treatment and is associated with a dismal outcome. An extensive list of mutations in hot spot regions of the genes encoding the target has been characterized and associated with species and drug-specific loss of susceptibility. The updated antifungal susceptibility testing reference methods identify echinocandin-resistant isolates reliably, although the performance of commercial tests is somewhat more variable. Alternative technologies are being developed, including molecular detection and matrix-assisted laser desorption ionization-time of flight. SUMMARY Echinocandin resistance is increasingly encountered and its occurrence makes susceptibility testing essential, particularly in patients with prior exposure. The further development of rapid and user-friendly commercially available susceptibility platforms is warranted. Antifungal stewardship is important in order to minimize unnecessary selection pressure.
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Arendrup MC, Posteraro B, Sanguinetti M, Guinea J. The State-of-the-Art Mycology Laboratory: Visions of the Future. Curr Fungal Infect Rep 2015; 9:37-51. [DOI: 10.1007/s12281-014-0212-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Abstract
Echinocandins are the newest antifungal agents approved for use in treating Candida infections in the US. They act by interfering with 1,3-β-D-glucan synthase and therefore disrupt cell wall production and lead to Candida cell death. There is no intrinsic resistance to echinocandins among Candida species, and isolates from historic collections archived before the release of the echinocandins show no resistance. Resistance to the echinocandins remains low among most Candida species and ranges overall from 0-1%. Among isolates of Candida glabrata, the proportion of resistant isolates is higher and has been reported to be as high as 13.5% in at least one hospital. Antifungal resistance is due to specific amino acid mutations in the Fksp subunit(s) of the 1,3-β-D-glucan synthase protein which are localized to one of two hotspots. These mutations are being recognized in isolates from patients who have failed echinocandin therapy, and often lead to a poor outcome. While the future looks bright for the echinocandins against most Candida species, C. glabrata remains a species of concern and resistance rates of C. glabrata to the echinocandins should be monitored closely.
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