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Sun H, Xiao D, Li X, Sun T, Meng F, Shao X, Ding Y, Li Y. Study on the chemical composition and anti-fungi activities of anthraquinones and its glycosides from Rumex japonicus Houtt. J Nat Med 2024:10.1007/s11418-024-01834-x. [PMID: 39103726 DOI: 10.1007/s11418-024-01834-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Accepted: 07/18/2024] [Indexed: 08/07/2024]
Abstract
Fungi, such as Trichophyton rubrum (T. rubrum) and Microsporum canis Bodin Anamorph (M. canis Bodin Anamorph) are the main pathogens of dermatophysis. According to ancient books records, Rumex japonicus Houtt. (RJH) has a miraculous effect on the treatment of dermatophysis. To reveal the anti-fungi (T. rubrum and M. canis Bodin Anamorph) components and its mechanism of the Rumex japonicus Houtt. The vinegar extraction and alcohol precipitation, HPLC and nuclear magnetic resonance spectroscopy (NMR) were employed for analyzing the chemical compositions of RJH; in vitro anti-fungal experiment was investigated including test the minimum inhibitory concentration (MIC) and the minimum fungicidal concentration (MFC), spore germination rate, nucleic acid, protein leakage rate, biofilm structure, and the mechanism of anti-fungal and anti-fungal biofilms in RJH. Seven anthraquinones and their glycoside compounds were obtained in this study respectively, such as chrysophanol, physcion, aloe-emodin, emodin, rhein, emodin-8-O-β-D-glucoside and chrysophanol-8-O-β-D-glucoside. In vitro anti-fungal experiment results showed that RJH extracts have good anti-fungal activity for dermatophytic fungi. Among them, the MIC of the rhein, emodin and aloe-emodin against T. rubrum are 1.9 µg/ml, 3.9 µg/ml and 15.6 µg/ml, respectively; the MIC of emodin and aloe-emodin against M. canis Bodin Anamorph are 7.8 µg/ml and 62.5 µg/ml, respectively. In addition, its active components can inhibit fungal spore germination and the formation of bud tube, change cell membrane permeability, prevent hyphal growth, destroy biofilm structure, and down-regulate the expression of agglutinin-like sequence family 1 of the adhesion phase of biofilm growth. The study shows that RJH play a fungicidal role.
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Affiliation(s)
- He Sun
- Department of School of Pharmaceutical Sciences, Changchun University of Chinese Medicine, Changchun, 130117, Jilin, People's Republic of China
| | - Dandan Xiao
- Department of Marine Life Sciences, Jeju National University, Jeju, 690-756, Korea
| | - Xue Li
- Department of School of Pharmaceutical Sciences, Changchun University of Chinese Medicine, Changchun, 130117, Jilin, People's Republic of China
| | - Tong Sun
- Department of School of Pharmaceutical Sciences, Changchun University of Chinese Medicine, Changchun, 130117, Jilin, People's Republic of China
| | - Fanying Meng
- Department of School of Pharmaceutical Sciences, Changchun University of Chinese Medicine, Changchun, 130117, Jilin, People's Republic of China
| | - Xinting Shao
- Department of School of Pharmaceutical Sciences, Changchun University of Chinese Medicine, Changchun, 130117, Jilin, People's Republic of China
| | - Yuling Ding
- Department of School of Pharmaceutical Sciences, Changchun University of Chinese Medicine, Changchun, 130117, Jilin, People's Republic of China.
| | - Yong Li
- Department of School of Pharmaceutical Sciences, Changchun University of Chinese Medicine, Changchun, 130117, Jilin, People's Republic of China.
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Diehl C, Pinzan CF, de Castro PA, Delbaje E, García Carnero LC, Sánchez-León E, Bhalla K, Kronstad JW, Kim DG, Doering TL, Alkhazraji S, Mishra NN, Ibrahim AS, Yoshimura M, Vega Isuhuaylas LA, Pham LTK, Yashiroda Y, Boone C, dos Reis TF, Goldman GH. Brilacidin, a novel antifungal agent against Cryptococcus neoformans. mBio 2024; 15:e0103124. [PMID: 38916308 PMCID: PMC11253610 DOI: 10.1128/mbio.01031-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 05/14/2024] [Indexed: 06/26/2024] Open
Abstract
Cryptococcus neoformans causes cryptococcosis, one of the most prevalent fungal diseases, generally characterized by meningitis. There is a limited and not very effective number of drugs available to combat this disease. In this manuscript, we show the host defense peptide mimetic brilacidin (BRI) as a promising antifungal drug against C. neoformans. BRI can affect the organization of the cell membrane, increasing the fungal cell permeability. We also investigated the effects of BRI against the model system Saccharomyces cerevisiae by analyzing libraries of mutants grown in the presence of BRI. In S. cerevisiae, BRI also affects the cell membrane organization, but in addition the cell wall integrity pathway and calcium metabolism. In vivo experiments show BRI significantly reduces C. neoformans survival inside macrophages and partially clears C. neoformans lung infection in an immunocompetent murine model of invasive pulmonary cryptococcosis. We also observed that BRI interacts with caspofungin (CAS) and amphotericin (AmB), potentiating their mechanism of action against C. neoformans. BRI + CAS affects endocytic movement, calcineurin, and mitogen-activated protein kinases. Our results indicate that BRI is a novel antifungal drug against cryptococcosis. IMPORTANCE Invasive fungal infections have a high mortality rate causing more deaths annually than tuberculosis or malaria. Cryptococcosis, one of the most prevalent fungal diseases, is generally characterized by meningitis and is mainly caused by two closely related species of basidiomycetous yeasts, Cryptococcus neoformans and Cryptococcus gattii. There are few therapeutic options for treating cryptococcosis, and searching for new antifungal agents against this disease is very important. Here, we present brilacidin (BRI) as a potential antifungal agent against C. neoformans. BRI is a small molecule host defense peptide mimetic that has previously exhibited broad-spectrum immunomodulatory/anti-inflammatory activity against bacteria and viruses. BRI alone was shown to inhibit the growth of C. neoformans, acting as a fungicidal drug, but surprisingly also potentiated the activity of caspofungin (CAS) against this species. We investigated the mechanism of action of BRI and BRI + CAS against C. neoformans. We propose BRI as a new antifungal agent against cryptococcosis.
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Affiliation(s)
- Camila Diehl
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Camila Figueiredo Pinzan
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Patrícia Alves de Castro
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Endrews Delbaje
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Laura C. García Carnero
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Eddy Sánchez-León
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Kabir Bhalla
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - James W. Kronstad
- Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Dong-gyu Kim
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Tamara L. Doering
- Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Sondus Alkhazraji
- Division of Infectious Diseases, The Lundquist Institute for Biomedical Innovation at Harbor-University of California Los Angeles (UCLA) Medical Center, Torrance, California, USA
| | - Nagendra N. Mishra
- Division of Infectious Diseases, The Lundquist Institute for Biomedical Innovation at Harbor-University of California Los Angeles (UCLA) Medical Center, Torrance, California, USA
- David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Ashraf S. Ibrahim
- Division of Infectious Diseases, The Lundquist Institute for Biomedical Innovation at Harbor-University of California Los Angeles (UCLA) Medical Center, Torrance, California, USA
- David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Mami Yoshimura
- RIKEN Center for Sustainable Resource Science, Wako, Saitama, Japan
| | | | | | - Yoko Yashiroda
- RIKEN Center for Sustainable Resource Science, Wako, Saitama, Japan
| | - Charles Boone
- RIKEN Center for Sustainable Resource Science, Wako, Saitama, Japan
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada
| | - Thaila Fernanda dos Reis
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Gustavo H. Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
- National Institute of Science and Technology in Human Pathogenic Fungi, São Paulo, Brazil
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Zhang ZH, Sun LL, Fu BQ, Deng J, Jia CL, Miao MX, Yang F, Cao YB, Yan TH. Aneuploidy underlies brefeldin A-induced antifungal drug resistance in Cryptococcus neoformans. Front Cell Infect Microbiol 2024; 14:1397724. [PMID: 38966251 PMCID: PMC11222406 DOI: 10.3389/fcimb.2024.1397724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Accepted: 05/17/2024] [Indexed: 07/06/2024] Open
Abstract
Cryptococcus neoformans is at the top of the list of "most wanted" human pathogens. Only three classes of antifungal drugs are available for the treatment of cryptococcosis. Studies on antifungal resistance mechanisms are limited to the investigation of how a particular antifungal drug induces resistance to a particular drug, and the impact of stresses other than antifungals on the development of antifungal resistance and even cross-resistance is largely unexplored. The endoplasmic reticulum (ER) is a ubiquitous subcellular organelle of eukaryotic cells. Brefeldin A (BFA) is a widely used chemical inducer of ER stress. Here, we found that both weak and strong selection by BFA caused aneuploidy formation in C. neoformans, mainly disomy of chromosome 1, chromosome 3, and chromosome 7. Disomy of chromosome 1 conferred cross-resistance to two classes of antifungal drugs: fluconazole and 5-flucytosine, as well as hypersensitivity to amphotericin B. However, drug resistance was unstable, due to the intrinsic instability of aneuploidy. We found overexpression of AFR1 on Chr1 and GEA2 on Chr3 phenocopied BFA resistance conferred by chromosome disomy. Overexpression of AFR1 also caused resistance to fluconazole and hypersensitivity to amphotericin B. Furthermore, a strain with a deletion of AFR1 failed to form chromosome 1 disomy upon BFA treatment. Transcriptome analysis indicated that chromosome 1 disomy simultaneously upregulated AFR1, ERG11, and other efflux and ERG genes. Thus, we posit that BFA has the potential to drive the rapid development of drug resistance and even cross-resistance in C. neoformans, with genome plasticity as the accomplice.
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Affiliation(s)
- Zhi-hui Zhang
- Institute of Vascular Disease, Shanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Liu-liu Sun
- Department of Pharmacy, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
| | - Bu-qing Fu
- Laboratory Department, Jiangsu Province Hospital of Chinese Medicine, Nanjing, China
| | - Jie Deng
- Institute of Vascular Disease, Shanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Cheng-lin Jia
- Institute of Vascular Disease, Shanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Ming-xing Miao
- Department of Physiology and Pharmacology, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Feng Yang
- Institute of Vascular Disease, Shanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- Department of Pharmacy, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yong-bing Cao
- Institute of Vascular Disease, Shanghai TCM-Integrated Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Tian-hua Yan
- Department of Physiology and Pharmacology, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, China
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Fiala J, Roach T, Holzinger A, Husiev Y, Delueg L, Hammerle F, Armengol ES, Schöbel H, Bonnet S, Laffleur F, Kranner I, Lackner M, Siewert B. The Light-activated Effect of Natural Anthraquinone Parietin against Candida auris and Other Fungal Priority Pathogens. PLANTA MEDICA 2024; 90:588-594. [PMID: 38843798 PMCID: PMC11156500 DOI: 10.1055/a-2249-9110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 01/05/2024] [Indexed: 06/10/2024]
Abstract
Antimicrobial photodynamic therapy (aPDT) is an evolving treatment strategy against human pathogenic microbes such as the Candida species, including the emerging pathogen C. auris. Using a modified EUCAST protocol, the light-enhanced antifungal activity of the natural compound parietin was explored. The photoactivity was evaluated against three separate strains of five yeasts, and its molecular mode of action was analysed via several techniques, i.e., cellular uptake, reactive electrophilic species (RES), and singlet oxygen yield. Under experimental conditions (λ = 428 nm, H = 30 J/cm2, PI = 30 min), microbial growth was inhibited by more than 90% at parietin concentrations as low as c = 0.156 mg/L (0.55 µM) for C. tropicalis and Cryptococcus neoformans, c = 0.313 mg/L (1.10 µM) for C. auris, c = 0.625 mg/L (2.20 µM) for C. glabrata, and c = 1.250 mg/L (4.40 µM) for C. albicans. Mode-of-action analysis demonstrated fungicidal activity. Parietin targets the cell membrane and induces cell death via ROS-mediated lipid peroxidation after light irradiation. In summary, parietin exhibits light-enhanced fungicidal activity against all Candida species tested (including C. auris) and Cryptococcus neoformans, covering three of the four critical threats on the WHO's most recent fungal priority list.
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Affiliation(s)
- Johannes Fiala
- Department of Pharmacognosy, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Austria
| | - Thomas Roach
- Department of Botany, University of Innsbruck, Austria
| | | | - Yurii Husiev
- Leiden Institute of Chemistry, Leiden University, Netherlands
| | - Lisa Delueg
- Department of Pharmacognosy, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Austria
| | - Fabian Hammerle
- Department of Pharmacognosy, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Austria
| | - Eva Sanchez Armengol
- Department of Technology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Austria
| | | | | | - Flavia Laffleur
- Department of Technology, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Austria
| | - Ilse Kranner
- Department of Botany, University of Innsbruck, Austria
| | - Michaela Lackner
- Institute of Hygiene und Medical Microbiology, Medical University of Innsbruck, Austria
| | - Bianka Siewert
- Department of Pharmacognosy, Institute of Pharmacy, Center for Molecular Biosciences Innsbruck, University of Innsbruck, Austria
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5
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Moussa AY. The limitless endophytes: their role as antifungal agents against top priority pathogens. Microb Cell Fact 2024; 23:161. [PMID: 38822407 PMCID: PMC11140875 DOI: 10.1186/s12934-024-02411-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 04/29/2024] [Indexed: 06/03/2024] Open
Abstract
Multi resistant fungi are on the rise, and our arsenal compounds are limited to few choices in the market such as polyenes, pyrimidine analogs, azoles, allylamines, and echinocandins. Although each of these drugs featured a unique mechanism, antifungal resistant strains did emerge and continued to arise against them worldwide. Moreover, the genetic variation between fungi and their host humans is small, which leads to significant challenges in new antifungal drug discovery. Endophytes are still an underexplored source of bioactive secondary metabolites. Many studies were conducted to isolate and screen endophytic pure compounds with efficacy against resistant yeasts and fungi; especially, Candida albicans, C. auris, Cryptococcus neoformans and Aspergillus fumigatus, which encouraged writing this review to critically analyze the chemical nature, potency, and fungal source of the isolated endophytic compounds as well as their novelty features and SAR when possible. Herein, we report a comprehensive list of around 320 assayed antifungal compounds against Candida albicans, C. auris, Cryptococcus neoformans and Aspergillus fumigatus in the period 1980-2024, the majority of which were isolated from fungi of orders Eurotiales and Hypocreales associated with terrestrial plants, probably due to the ease of laboratory cultivation of these strains. 46% of the reviewed compounds were active against C. albicans, 23% against C. neoformans, 29% against A. fumigatus and only 2% against C. auris. Coculturing was proved to be an effective technique to induce cryptic metabolites absent in other axenic cultures or host extract cultures, with Irperide as the most promising compounds MIC value 1 μg/mL. C. auris was susceptible to only persephacin and rubiginosin C. The latter showed potent inhibition against this recalcitrant strain in a non-fungicide way, which unveils the potential of fungal biofilm inhibition. Further development of culturing techniques and activation of silent metabolic pathways would be favorable to inspire the search for novel bioactive antifungals.
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Affiliation(s)
- Ashaimaa Y Moussa
- Department of Pharmacognosy, Faculty of Pharmacy, Ain-Shams University, African Union Organization Street, Abbassia, Cairo, 11566, Egypt.
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Melhem MSC, Leite Júnior DP, Takahashi JPF, Macioni MB, Oliveira LD, de Araújo LS, Fava WS, Bonfietti LX, Paniago AMM, Venturini J, Espinel-Ingroff A. Antifungal Resistance in Cryptococcal Infections. Pathogens 2024; 13:128. [PMID: 38392866 PMCID: PMC10891860 DOI: 10.3390/pathogens13020128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 01/20/2024] [Accepted: 01/22/2024] [Indexed: 02/25/2024] Open
Abstract
Antifungal therapy, especially with the azoles, could promote the incidence of less susceptible isolates of Cryptococcus neoformans and C. gattii species complexes (SC), mostly in developing countries. Given that these species affect mostly the immunocompromised host, the infections are severe and difficult to treat. This review encompasses the following topics: 1. infecting species and their virulence, 2. treatment, 3. antifungal susceptibility methods and available categorical endpoints, 4. genetic mechanisms of resistance, 5. clinical resistance, 6. fluconazole minimal inhibitory concentrations (MICs), clinical outcome, 7. environmental influences, and 8. the relevance of host factors, including pharmacokinetic/pharmacodynamic (PK/PD) parameters, in predicting the clinical outcome to therapy. As of now, epidemiologic cutoff endpoints (ECVs/ECOFFs) are the most reliable antifungal resistance detectors for these species, as only one clinical breakpoint (amphotericin B and C. neoformans VNI) is available.
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Affiliation(s)
- Marcia S C Melhem
- Graduate Program in Sciences, Secretary of Health, São Paulo 01246-002, SP, Brazil
- Graduate Program in Infectious and Parasitic Diseases, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, MS, Brazil
- Graduate Program in Tropical Diseases, State University of São Paulo, Botucatu 18618-687, SP, Brazil
| | | | - Juliana P F Takahashi
- Graduate Program in Infectious and Parasitic Diseases, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, MS, Brazil
- Pathology Division, Adolfo Lutz Institute, São Paulo 01246-002, SP, Brazil
| | | | | | - Lisandra Siufi de Araújo
- Graduate Program in Infectious and Parasitic Diseases, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, MS, Brazil
- Central Public Health Laboratory-LACEN, Mycology Unit, Adolfo Lutz Institut, São Paulo 01246-002, SP, Brazil
| | - Wellington S Fava
- Graduate Program in Infectious and Parasitic Diseases, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, MS, Brazil
| | - Lucas X Bonfietti
- Central Public Health Laboratory-LACEN, Mycology Unit, Adolfo Lutz Institut, São Paulo 01246-002, SP, Brazil
| | - Anamaria M M Paniago
- Graduate Program in Infectious and Parasitic Diseases, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, MS, Brazil
| | - James Venturini
- Graduate Program in Infectious and Parasitic Diseases, Federal University of Mato Grosso do Sul, Campo Grande 79070-900, MS, Brazil
| | - Ana Espinel-Ingroff
- Central Public Health Laboratory-LACEN, Campo Grande 79074-460, MS, Brazil
- VCU Medical Center, Richmond, VA 23284, USA
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Ordaya EE, Abu Saleh OM, Vergidis P, Deml SM, Wengenack NL, Fida M. Temporal trends in antifungal susceptibility of Cryptococcus neoformans isolates from a reference laboratory in the United States, 2011-2021. Mycoses 2024; 67:e13691. [PMID: 38214377 DOI: 10.1111/myc.13691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 12/10/2023] [Accepted: 12/17/2023] [Indexed: 01/13/2024]
Abstract
BACKGROUND There are no established clinical breakpoints for antifungal agents against Cryptococcus species; however, epidemiological cut-off values can help distinguish wild-type (WT) isolates without any acquired resistance from non-WT strains, which may harbour resistance mechanisms. PATIENTS/METHODS We describe the trends of antifungal MICs and percentages of WT C. neoformans species complex (CNSC) isolates processed in our reference laboratory from November 2011 to June 2021. There were only nine isolates in 2011, thus, we included them in the year 2012 for data analysis. Clinical data is also described when available. RESULTS We identified 632 CNSC, the majority collected from blood (n = 301), cerebrospinal fluid (n = 230), and respiratory (n = 71) sources. The overall percentage of WT isolates for amphotericin B (AMB), 5-flucytosine, and fluconazole was 77%, 98%, and 91%, respectively. We noticed a statistically significant change in the percentage of AMB WT isolates over the years, with 98% of isolates being WT in 2012 compared to 79% in 2021 (p < .01). A similar change was not observed for other antifungal agents. Clinical data was available for 36 patients, primarily non-HIV immunocompromised patients with disseminated cryptococcosis. There were no statistically significant differences in the clinical characteristics and outcomes between patients with WT (58.3%) versus non-WT (41.7%) isolates, but we noticed higher mortality in patients infected with an AMB non-WT CNSC isolate. CONCLUSIONS We observed an increase in the percentage of AMB non-WT CNSC isolates in the past decade. The clinical implications of this finding warrant further evaluation in larger studies.
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Affiliation(s)
- Eloy E Ordaya
- Division of Public Health, Infectious Diseases, and Occupational Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Omar M Abu Saleh
- Division of Public Health, Infectious Diseases, and Occupational Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Paschalis Vergidis
- Division of Public Health, Infectious Diseases, and Occupational Medicine, Mayo Clinic, Rochester, Minnesota, USA
| | - Sharon M Deml
- Division of Clinical Microbiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Nancy L Wengenack
- Division of Clinical Microbiology, Mayo Clinic, Rochester, Minnesota, USA
| | - Madiha Fida
- Division of Public Health, Infectious Diseases, and Occupational Medicine, Mayo Clinic, Rochester, Minnesota, USA
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Lockhart SR, Chowdhary A, Gold JAW. The rapid emergence of antifungal-resistant human-pathogenic fungi. Nat Rev Microbiol 2023; 21:818-832. [PMID: 37648790 DOI: 10.1038/s41579-023-00960-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2023] [Indexed: 09/01/2023]
Abstract
During recent decades, the emergence of pathogenic fungi has posed an increasing public health threat, particularly given the limited number of antifungal drugs available to treat invasive infections. In this Review, we discuss the global emergence and spread of three emerging antifungal-resistant fungi: Candida auris, driven by global health-care transmission and possibly facilitated by climate change; azole-resistant Aspergillus fumigatus, driven by the selection facilitated by azole fungicide use in agricultural and other settings; and Trichophyton indotineae, driven by the under-regulated use of over-the-counter high-potency corticosteroid-containing antifungal creams. The diversity of the fungi themselves and the drivers of their emergence make it clear that we cannot predict what might emerge next. Therefore, vigilance is critical to monitoring fungal emergence, as well as the rise in overall antifungal resistance.
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Affiliation(s)
- Shawn R Lockhart
- Mycotic Diseases Branch, Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA.
| | - Anuradha Chowdhary
- Medical Mycology Unit, Department of Microbiology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
- National Reference Laboratory for Antimicrobial Resistance in Fungal Pathogens, Medical Mycology Unit, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Jeremy A W Gold
- Mycotic Diseases Branch, Division of Foodborne, Waterborne, and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
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Pereira TC, do Carmo PHF, de Menezes RT, de Oliveira HC, de Oliveira LD, Junqueira JC, Scorzoni L. Synergistic effect of the verapamil and amphotericin B against Cryptococcus neoformans. Folia Microbiol (Praha) 2023; 68:999-1004. [PMID: 37950840 DOI: 10.1007/s12223-023-01104-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 10/30/2023] [Indexed: 11/13/2023]
Abstract
Cryptococcus neoformans is an encapsulated yeast that can cause cryptococcosis and cryptococcal meningitis, which conventional treatment involves antifungal drugs such as polyenes, flucytosine, azoles, and their combinations. However, the high cost, toxicity, and increase in fungi resistance to antifungal agents stimulate the search for therapeutic strategies such as drug repurposing and combination therapy. This study evaluated the activity of the antihypertensive verapamil (VEH) alone and combined with amphotericin B (AmB) against C. neoformans. VEH exhibited antifungal activity against C. neoformans with minimum inhibitory concentration and minimum fungicidal concentration of 118 µg per mL. The combination of VEH and AmB exhibited synergism, reducing at least eightfold both drugs' concentrations. Moreover, the combination decreased the size and glucuronoxylomannnan content of C. neoformans capsule. However, no difference was observed in ergosterol levels of C. neoformans after treatment with VEH and AmB in combination. Altogether, VEH in combination with AmB exhibits potential as a candidate as for the development of anti-cryptococcal drug.
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Affiliation(s)
- Thaís C Pereira
- Department of Biosciences and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (UNESP), São José dos Campos, SP, 12245-000, Brazil
| | - Paulo H F do Carmo
- Department of Biosciences and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (UNESP), São José dos Campos, SP, 12245-000, Brazil
| | - Raquel T de Menezes
- Department of Biosciences and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (UNESP), São José dos Campos, SP, 12245-000, Brazil
| | | | - Luciane D de Oliveira
- Department of Biosciences and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (UNESP), São José dos Campos, SP, 12245-000, Brazil
| | - Juliana C Junqueira
- Department of Biosciences and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (UNESP), São José dos Campos, SP, 12245-000, Brazil
| | - Liliana Scorzoni
- Department of Biosciences and Oral Diagnosis, Institute of Science and Technology, São Paulo State University (UNESP), São José dos Campos, SP, 12245-000, Brazil.
- Universidade de Guarulhos (UNG), Programa de Pós-Graduação em Enfermagem, Guarulhos, SP, Brazil.
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10
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Elalouf A, Yaniv-Rosenfeld A. Immunoinformatic-guided designing and evaluating protein and mRNA-based vaccines against Cryptococcus neoformans for immunocompromised patients. J Genet Eng Biotechnol 2023; 21:108. [PMID: 37882985 PMCID: PMC10603020 DOI: 10.1186/s43141-023-00560-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 10/08/2023] [Indexed: 10/27/2023]
Abstract
BACKGROUND Cryptococcus neoformans is a fungal pathogen that can cause serious meningoencephalitis in individuals with compromised immune systems due to HIV/AIDS (human immunodeficiency virus/acquired immunodeficiency syndrome), liver cirrhosis, and transplantation. Mannoproteins (MPs), glycoproteins in the C. neoformans capsule, crucially impact virulence by mediating adhesion to lung cells and modulating immune response via cytokine induction and phagocytosis influence. Therefore, creating a vaccine that can generate targeted antibodies to fight infection and prevent fungal illnesses is essential. RESULTS This research aims to create a unique, stable, and safe vaccine through bioinformatics methodologies, aiming at epitopes of T and B cells found in the MP of C. neoformans. Based on toxicity, immunogenicity, and antigenicity, this research predicted novel T cells (GNPVGGNVT, NPVGGNVTT, QTSYARLLS, TSVGNGIAS, WVMPGDYTN, AAATGSSSSGSTGSG, GSTGSGSGSAAAGST, SGSTGSGSGSAAAGS, SSGSTGSGSGSAAAG, and SSSGSTGSGSGSAAA) and B cell (ANGSTSTFQQRYTGTYTNGDGSLGTWTQGETVTPQTAYSTPATSNCKTYTSVGNGIASLALSNAGSNSTAAATNSSSGGASAAATGSSSSGSTGSGSGSAAAGSTAAASSSGDSSSSTSAAMSNGI, HGATGLGNPVGGNVTT, TMGPTNPSEPTLGTAI, GNPVGGNVTTNATGSD, and NSTAAATNSSSGGASA) epitopes for a multiple-epitope vaccine and constructed a vaccine subunit with potential immunogenic properties. The present study used four linkers (AAY, GPGPG, KK, and EAAAK linkers) to connect the epitopes and adjuvant. After constructing the vaccine, it was confronted with receptor docking and simulation analysis. Subsequently, the vaccine was cloned into the vector of Escherichia coli pET-28a ( +) by ligation process for the expression using the SnapGene tool, which confirmed a significant immune response. To assess the constructed vaccine's properties, multiple computational tools were employed. Based on the MP sequence, the tools evaluated the antigenicity, immunogenicity, cytokine-inducing capacity, allergenicity, toxicity, population coverage, and solubility. CONCLUSION Eventually, the results revealed a promising multi-epitope vaccine as a potential candidate for addressing global C. neoformans infection, particularly in immunocompromised patients. Yet, additional in vitro and in vivo investigations are necessary to validate its safety and effectiveness.
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Affiliation(s)
- Amir Elalouf
- Department of Management, Bar-Ilan University, Ramat Gan, 5290002, Israel.
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11
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Ma Y, Yang L, Jiang M, Zhao X, Xue P. Connecting Cryptococcal Meningitis and Gut Microbiome. Int J Mol Sci 2023; 24:13515. [PMID: 37686320 PMCID: PMC10487799 DOI: 10.3390/ijms241713515] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/27/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023] Open
Abstract
Fungal pathogens of the Cryptococcus neoformans species complex (C. neoformans SC) are a major cause of fungal meningitis in immunocompromised individuals. As with other melanotic microorganisms associated with human diseases, the cell-wall-associated melanin of C. neoformans SC is a major virulence factor that contributes to its ability to evade host immune responses. The levels of melanin substrate and the regulation of melanin formation could be influenced by the microbiota-gut-brain axis. Moreover, recent studies show that C. neoformans infections cause dysbiosis in the human gut microbiome. In this review, we discuss the potential association between cryptococcal meningitis and the gut microbiome. Additionally, the significant potential of targeting the gut microbiome in the diagnosis and treatment of this debilitating disease is emphasized.
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Affiliation(s)
- Yuanyuan Ma
- Nantong Key Laboratory of Environmental Toxicology, Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019, China; (Y.M.); (M.J.)
| | - Liang Yang
- School of Medicine, Southern University of Science and Technology, Shenzhen 518055, China;
| | - Mengna Jiang
- Nantong Key Laboratory of Environmental Toxicology, Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019, China; (Y.M.); (M.J.)
| | - Xinyuan Zhao
- Nantong Key Laboratory of Environmental Toxicology, Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019, China; (Y.M.); (M.J.)
| | - Peng Xue
- Nantong Key Laboratory of Environmental Toxicology, Department of Occupational Medicine and Environmental Toxicology, School of Public Health, Nantong University, Nantong 226019, China; (Y.M.); (M.J.)
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12
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Ambrosio FJ, Scribner MR, Wright SM, Otieno JR, Doughty EL, Gorzalski A, Siao DD, Killian S, Hua C, Schneider E, Tran M, Varghese V, Libuit KG, Pandori M, Sevinsky JR, Hess D. TheiaEuk: a species-agnostic bioinformatics workflow for fungal genomic characterization. Front Public Health 2023; 11:1198213. [PMID: 37593727 PMCID: PMC10428623 DOI: 10.3389/fpubh.2023.1198213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 07/04/2023] [Indexed: 08/19/2023] Open
Abstract
Introduction The clinical incidence of antimicrobial-resistant fungal infections has dramatically increased in recent years. Certain fungal pathogens colonize various body cavities, leading to life-threatening bloodstream infections. However, the identification and characterization of fungal isolates in laboratories remain a significant diagnostic challenge in medicine and public health. Whole-genome sequencing provides an unbiased and uniform identification pipeline for fungal pathogens but most bioinformatic analysis pipelines focus on prokaryotic species. To this end, TheiaEuk_Illumina_PE_PHB (TheiaEuk) was designed to focus on genomic analysis specialized to fungal pathogens. Methods TheiaEuk was designed using containerized components and written in the workflow description language (WDL) to facilitate deployment on the cloud-based open bioinformatics platform Terra. This species-agnostic workflow enables the analysis of fungal genomes without requiring coding, thereby reducing the entry barrier for laboratory scientists. To demonstrate the usefulness of this pipeline, an ongoing outbreak of C. auris in southern Nevada was investigated. We performed whole-genome sequence analysis of 752 new C. auris isolates from this outbreak. Furthermore, TheiaEuk was utilized to observe the accumulation of mutations in the FKS1 gene over the course of the outbreak, highlighting the utility of TheiaEuk as a monitor of emerging public health threats when combined with whole-genome sequencing surveillance of fungal pathogens. Results A primary result of this work is a curated fungal database containing 5,667 unique genomes representing 245 species. TheiaEuk also incorporates taxon-specific submodules for specific species, including clade-typing for Candida auris (C. auris). In addition, for several fungal species, it performs dynamic reference genome selection and variant calling, reporting mutations found in genes currently associated with antifungal resistance (FKS1, ERG11, FUR1). Using genome assemblies from the ATCC Mycology collection, the taxonomic identification module used by TheiaEuk correctly assigned genomes to the species level in 126/135 (93.3%) instances and to the genus level in 131/135 (97%) of instances, and provided zero false calls. Application of TheiaEuk to actual specimens obtained in the course of work at a local public health laboratory resulted in 13/15 (86.7%) correct calls at the species level, with 2/15 called at the genus level. It made zero incorrect calls. TheiaEuk accurately assessed clade type of Candida auris in 297/302 (98.3%) of instances. Discussion TheiaEuk demonstrated effectiveness in identifying fungal species from whole genome sequence. It further showed accuracy in both clade-typing of C. auris and in the identification of mutations known to associate with drug resistance in that organism.
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Affiliation(s)
| | | | | | | | | | | | | | - Steve Killian
- Alameda County Public Health Laboratory, Oakland, CA, United States
| | - Chi Hua
- Public Health Laboratories, Division of Disease Control and Health Statistics, Washington State Department of Health, Shoreline, WA, United States
| | - Emily Schneider
- Public Health Laboratories, Division of Disease Control and Health Statistics, Washington State Department of Health, Shoreline, WA, United States
| | - Michael Tran
- Public Health Laboratories, Division of Disease Control and Health Statistics, Washington State Department of Health, Shoreline, WA, United States
| | - Vici Varghese
- Alameda County Public Health Laboratory, Oakland, CA, United States
| | | | - Mark Pandori
- Nevada State Public Health Laboratory, Reno, NV, United States
- Department of Pathology and Laboratory Medicine, Reno School of Medicine, University of Nevada, Reno, NV, United States
- Department of Microbiology and Immunology, Reno School of Medicine, University of Nevada, Reno, NV, United States
| | | | - David Hess
- Nevada State Public Health Laboratory, Reno, NV, United States
- Department of Pathology and Laboratory Medicine, Reno School of Medicine, University of Nevada, Reno, NV, United States
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Drakulovski P, Krasteva D, Bellet V, Randazzo S, Roger F, Pottier C, Bertout S. Exposure of Cryptococcus neoformans to Seven Commonly Used Agricultural Azole Fungicides Induces Resistance to Fluconazole as Well as Cross-Resistance to Voriconazole, Posaconazole, Itraconazole and Isavuconazole. Pathogens 2023; 12:pathogens12050662. [PMID: 37242332 DOI: 10.3390/pathogens12050662] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 04/20/2023] [Accepted: 04/27/2023] [Indexed: 05/28/2023] Open
Abstract
BACKGROUND Cross-resistance to medical azoles by exposure to azole pesticides is well documented for Aspergillus family fungi but is poorly evaluated for other environmental pathogen fungi, particularly for yeasts belonging to the Cryptococcus neoformans/Cryptococcus gattii species complexes. METHODS One thousand C. neoformans yeast were exposed to various concentrations of seven different commonly used azole pesticides. Clones surviving exposure were picked randomly, and their minimal inhibitory concentrations (MICs) of fluconazole, voriconazole, posaconazole, itraconazole and isavuconazole were assessed. RESULTS Depending on the pesticide used for exposure, up to 13.3% of selected Cryptococcus colonies showed a phenotype of resistance to fluconazole, and among them, several showed cross-resistance to another or several other medical azoles. Molecular mechanisms involved in the resistance setups seem to be dependent on ERG11 and AFR1 gene overexpression. CONCLUSION Exposure to any of the seven azole pesticides tested is capable of increasing the MIC of fluconazole in C. neoformans, including up to the level of the fluconazole-resistant phenotype, as well as generating cross-resistance to other medical azoles in some cases.
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Affiliation(s)
- Pascal Drakulovski
- Laboratoire de Parasitologie et Mycologie Médicale, UMI 233 TransVIHMI, University of Montpellier, IRD, INSERM U1175, 15 Avenue Charles Flahaut, 34093 Montpellier, France
| | - Donika Krasteva
- Laboratoire de Parasitologie et Mycologie Médicale, UMI 233 TransVIHMI, University of Montpellier, IRD, INSERM U1175, 15 Avenue Charles Flahaut, 34093 Montpellier, France
| | - Virginie Bellet
- Laboratoire de Parasitologie et Mycologie Médicale, UMI 233 TransVIHMI, University of Montpellier, IRD, INSERM U1175, 15 Avenue Charles Flahaut, 34093 Montpellier, France
| | - Sylvie Randazzo
- Laboratoire de Parasitologie et Mycologie Médicale, UMI 233 TransVIHMI, University of Montpellier, IRD, INSERM U1175, 15 Avenue Charles Flahaut, 34093 Montpellier, France
| | - Frédéric Roger
- Laboratoire de Parasitologie et Mycologie Médicale, UMI 233 TransVIHMI, University of Montpellier, IRD, INSERM U1175, 15 Avenue Charles Flahaut, 34093 Montpellier, France
| | - Cyrille Pottier
- Laboratoire de Parasitologie et Mycologie Médicale, UMI 233 TransVIHMI, University of Montpellier, IRD, INSERM U1175, 15 Avenue Charles Flahaut, 34093 Montpellier, France
| | - Sébastien Bertout
- Laboratoire de Parasitologie et Mycologie Médicale, UMI 233 TransVIHMI, University of Montpellier, IRD, INSERM U1175, 15 Avenue Charles Flahaut, 34093 Montpellier, France
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Yavari SK, Lapoint D, Levy A, Pourafkari L. Cryptococcal endocarditis of native valve in a patient with systemic lupus erythematosus. North Clin Istanb 2023; 10:277-280. [PMID: 37181051 PMCID: PMC10170374 DOI: 10.14744/nci.2023.04372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 02/02/2023] [Indexed: 02/17/2023] Open
Abstract
Cryptococcal endocarditis is an exceedingly rare entity associated with high mortality and morbidity. Hereby, we present a 37-year-old patient with underlying systemic lupus erythematosus and end-stage renal disease who was diagnosed with cryptococcal endocarditis involving native mitral valve. Her blood culture grew Cryptococcus neoformans. Echocardiography confirmed presence of vegetations and patient underwent mitral valve replacement and received appropriate anti-fungal treatment. Her course was further complicated by sternal wound dehiscence and infection of hemodialysis site as well as atrial flutter. Unfortunately, patient passed 2 weeks after discharge from hospital. C. neoformans is typically known to cause serious central nervous system. However, this pathogen can rarely cause serious infective endocarditis case particularly in immune compromised patients or those with prosthetic valves. Fungal endocarditis is usually treated with a combination of surgery and anti-fungal medications.
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Affiliation(s)
| | - Danielle Lapoint
- Catholic Health System, University at Buffalo, Buffalo, New York, USA
| | - Amanda Levy
- New York Institute of Technology College of Osteopathic Medicine, New York City, New York, USA
| | - Leili Pourafkari
- Catholic Health System, University at Buffalo, Buffalo, New York, USA
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15
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De Jesus DFF, De Freitas ALD, De Oliveira IM, De Almeida LC, Bastos RW, Spadari CDC, Melo ASDA, Santos DDA, Costa-Lotufo LV, Reis FCG, Rodrigues ML, Stefani HA, Ishida K. Organoselenium Has a Potent Fungicidal Effect on Cryptococcus neoformans and Inhibits the Virulence Factors. Antimicrob Agents Chemother 2023; 67:e0075922. [PMID: 36815840 PMCID: PMC10019174 DOI: 10.1128/aac.00759-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 01/14/2023] [Indexed: 02/24/2023] Open
Abstract
Cryptococcosis therapy is often limited by toxicity problems, antifungal tolerance, and high costs. Studies approaching chalcogen compounds, especially those containing selenium, have shown promising antifungal activity against pathogenic species. This work aimed to evaluate the in vitro and in vivo antifungal potential of organoselenium compounds against Cryptococcus neoformans. The lead compound LQA_78 had an inhibitory effect on C. neoformans planktonic cells and dispersed cells from mature biofilms at similar concentrations. The fungal growth inhibition led to an increase in budding cells arrested in the G2/M phase, but the compound did not significantly affect structural cell wall components or chitinase activity, an enzyme that regulates the dynamics of the cell wall. The compound also inhibited titan cell (Tc) and enlarged capsule yeast (NcC) growth and reduced the body diameter and capsule thickness associated with increased capsular permeability of both virulent morphotypes. LQA_78 also reduced fungal melanization through laccase activity inhibition. The fungicidal activity was observed at higher concentrations (16 to 64 μg/mL) and may be associated with augmented plasma membrane permeability, ROS production, and loss of mitochondrial membrane potential. While LQA_78 is a nonhemolytic compound, its cytotoxic effects were cell type dependent, exhibiting no toxicity on Galleria mellonella larvae at a dose ≤46.5 mg/kg. LQA_78 treatment of larvae infected with C. neoformans effectively reduced the fungal burden and inhibited virulent morphotype formation. To conclude, LQA_78 displays fungicidal action and inhibits virulence factors of C. neoformans. Our results highlight the potential use of LQA_78 as a lead molecule for developing novel pharmaceuticals for treating cryptococcosis.
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Affiliation(s)
| | | | | | | | - Rafael Wesley Bastos
- Center of Biosciences, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil
| | | | | | - Daniel de Assis Santos
- Institute of Biomedical Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | | | - Flavia C. G. Reis
- Carlos Chagas Institute, Oswaldo Cruz Foundation, Curitiba, Brazil
- Center for Technological Development in Health (CDTS), Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Marcio L. Rodrigues
- Carlos Chagas Institute, Oswaldo Cruz Foundation, Curitiba, Brazil
- Institute of Microbiology Paulo de Góes, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | | | - Kelly Ishida
- Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, Brazil
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16
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Krishnan S, Gupta K, Sivaraman S, Venkatachalam P, Yennamalli RM, Shanmugam SR. Waste to drugs: identification of pyrolysis by-products as antifungal agents against Cryptococcus neoformans. J Biomol Struct Dyn 2023; 41:15386-15399. [PMID: 36927454 DOI: 10.1080/07391102.2023.2188960] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 02/28/2023] [Indexed: 03/18/2023]
Abstract
The fungi, Cryptococcus neoformans cause major infections such as cryptococcal meningitis and cryptococcosis. Therefore, we explored the use of Thioredoxin reductase (Trr1) from C. neoformans as a gene target for the development of novel antifungal agents. Trr1 plays an essential role in the survival in the oxidative environment of macrophages and is important for the virulence of C. neoformans. During the thermochemical conversion (pyrolysis) of lignocellulosic biomass (LCB), a cocktail of compounds is produced by the decomposition and degradation. In general, LCB-derived cocktail of compounds is a rich source of aromatic compounds that have been shown to be antifungal in nature. Usually, the aqueous phase produced during biomass pyrolysis is generally regarded as waste. Here, we used Parthenium hysterophorus biomass as the antifungal source and obtained the aqueous phase after pyrolysis. Using GC-MS analysis of the aqueous phase collected from P. hysterophorus biomass revealed the presence of a large number of aromatic and organic compounds. Using virtual screening, the compounds present in the aqueous phase were docked against Trr1 using GLIDE. Two promising candidates were analyzed further by performing molecular dynamics simulation using GROMACS, to establish stable interactions. We validated the computational results with clustering analysis. We report that 2,4-Di-tertbutyl phenol and 1H-Pyrazole, 4-ethyl-3,5-dimethyl have a potent antifungal property and we postulate that they could be a potent antifungal agent against Trr1 of C. neoformans.
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Affiliation(s)
- Srividhya Krishnan
- Department of Biotechnology, School of Chemical & Biotechnology, SASTRA Deemed University, Thanjavur, India
- Centre for Bioenergy, SASTRA Deemed University, Thanjavur, India
| | - Krishnakant Gupta
- Department of Bioinformatics, School of Chemical & Biotechnology, SASTRA Deemed University, Thanjavur, India
| | - Subramaniyasharma Sivaraman
- Department of Biotechnology, School of Chemical & Biotechnology, SASTRA Deemed University, Thanjavur, India
- Centre for Bioenergy, SASTRA Deemed University, Thanjavur, India
| | - Ponnusami Venkatachalam
- Department of Biotechnology, School of Chemical & Biotechnology, SASTRA Deemed University, Thanjavur, India
- Centre for Bioenergy, SASTRA Deemed University, Thanjavur, India
| | - Ragothaman M Yennamalli
- Department of Bioinformatics, School of Chemical & Biotechnology, SASTRA Deemed University, Thanjavur, India
| | - Saravanan Ramiah Shanmugam
- Department of Biotechnology, School of Chemical & Biotechnology, SASTRA Deemed University, Thanjavur, India
- Centre for Bioenergy, SASTRA Deemed University, Thanjavur, India
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Martins-Santana L, Rezende CP, Rossi A, Martinez-Rossi NM, Almeida F. Addressing Microbial Resistance Worldwide: Challenges over Controlling Life-Threatening Fungal Infections. Pathogens 2023; 12:pathogens12020293. [PMID: 36839565 PMCID: PMC9961291 DOI: 10.3390/pathogens12020293] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 02/02/2023] [Accepted: 02/03/2023] [Indexed: 02/12/2023] Open
Abstract
Fungal infections are a serious global concern because of their ability to spread and colonize host tissues in immunocompromised individuals. Such infections have been frequently reported worldwide and are currently gaining clinical research relevance owing to their resistant character, representing a bottleneck in treating affected people. Resistant fungi are an emergent public health threat. The upsurge of such pathogens has led to new research toward unraveling the destructive potential evoked by these species. Some fungi-grouped into Candida, Aspergillus, and Cryptococcus-are causative agents of severe and systemic infections. They are associated with high mortality rates and have recently been described as sources of coinfection in COVID-hospitalized patients. Despite the efforts to elucidate the challenges of colonization, dissemination, and infection severity, the immunopathogenesis of fungal diseases remains a pivotal characteristic in fungal burden elimination. The struggle between the host immune system and the physiological strategies of the fungi to maintain cellular viability is complex. In this brief review, we highlight the relevance of drug resistance phenotypes in fungi of clinical significance, taking into consideration their physiopathology and how the scientific community could orchestrate their efforts to avoid fungal infection dissemination and deaths.
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Affiliation(s)
- Leonardo Martins-Santana
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14040-900, Brazil
| | - Caroline Patini Rezende
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14040-900, Brazil
| | - Antonio Rossi
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14040-900, Brazil
| | - Nilce Maria Martinez-Rossi
- Department of Genetics, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14040-900, Brazil
| | - Fausto Almeida
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14040-900, Brazil
- Correspondence:
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Giving a Hand: Synthetic Peptides Boost the Antifungal Activity of Itraconazole against Cryptococcus neoformans. Antibiotics (Basel) 2023; 12:antibiotics12020256. [PMID: 36830167 PMCID: PMC9952215 DOI: 10.3390/antibiotics12020256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/22/2023] [Accepted: 01/25/2023] [Indexed: 01/31/2023] Open
Abstract
Cryptococcus neoformans is a multidrug-resistant pathogen responsible for infections in immunocompromised patients. Here, itraconazole (ITR), a commercial antifungal drug with low effectiveness against C. neoformans, was combined with different synthetic antimicrobial peptides (SAMPs), Mo-CBP3-PepII, RcAlb-PepII, RcAlb-PepIII, PepGAT, and PepKAA. The Mo-CBP3-PepII was designed based on the sequence of MoCBP3, purified from Moringa oleifera seeds. RcAlb-PepII and RcAlb-PepIII were designed using Rc-2S-Alb, purified from Ricinus communis seed cakes. The putative sequence of a chitinase from Arabidopsis thaliana was used to design PepGAT and PepKAA. All SAMPs have a positive liquid charge and a hydrophobic potential ranging from 41-65%. The mechanisms of action responsible for the combined effect were evaluated for the best combinations using fluorescence microscopy (FM). The synthetic peptides enhanced the activity of ITR by 10-fold against C. neoformans. Our results demonstrated that the combinations could induce pore formation in the membrane and the overaccumulation of ROS on C. neoformans cells. Our findings indicate that our peptides successfully potentialize the activity of ITR against C. neoformans. Therefore, synthetic peptides are potential molecules to assist antifungal agents in treating Cryptococcal infections.
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Behind the Curtain: In Silico and In Vitro Experiments Brought to Light New Insights into the Anticryptococcal Action of Synthetic Peptides. Antibiotics (Basel) 2023; 12:antibiotics12010153. [PMID: 36671354 PMCID: PMC9854638 DOI: 10.3390/antibiotics12010153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/08/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
Cryptococcus neoformans is the pathogen responsible for cryptococcal pneumonia and meningitis, mainly affecting patients with suppressed immune systems. We have previously revealed the mechanism of anticryptococcal action of synthetic antimicrobial peptides (SAMPs). In this study, computational and experimental analyses provide new insights into the mechanisms of action of SAMPs. Computational analysis revealed that peptides interacted with the PHO36 membrane receptor of C. neoformans. Additionally, ROS (reactive oxygen species) overproduction, the enzymes of ROS metabolism, interference in the ergosterol biosynthesis pathway, and decoupling of cytochrome c mitochondrial membrane were evaluated. Three of four peptides were able to interact with the PHO36 receptor, altering its function and leading to ROS overproduction. SAMPs-treated C. neoformans cells showed a decrease in scavenger enzyme activity, supporting ROS accumulation. In the presence of ascorbic acid, an antioxidant agent, SAMPs did not induce ROS accumulation in C. neoformans cells. Interestingly, two SAMPs maintained inhibitory activity and membrane pore formation in C. neoformans cells by a ROS-independent mechanism. Yet, the ergosterol biosynthesis and lactate dehydrogenase activity were affected by SAMPs. In addition, we noticed decoupling of Cyt c from the mitochondria, which led to apoptosis events in the cryptococcal cells. The results presented herein suggest multiple mechanisms imposed by SAMPs against C. neoformans interfering in the development of resistance, thus revealing the potential of SAMPs in treating infections caused by C. neoformans.
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Garvey M, Meade E, Rowan NJ. Effectiveness of front line and emerging fungal disease prevention and control interventions and opportunities to address appropriate eco-sustainable solutions. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 851:158284. [PMID: 36029815 DOI: 10.1016/j.scitotenv.2022.158284] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 08/21/2022] [Accepted: 08/21/2022] [Indexed: 06/15/2023]
Abstract
Fungal pathogens contribute to significant disease burden globally; however, the fact that fungi are eukaryotes has greatly complicated their role in fungal-mediated infections and alleviation. Antifungal drugs are often toxic to host cells and there is increasing evidence of adaptive resistance in animals and humans. Existing fungal diagnostic and treatment regimens have limitations that has contributed to the alarming high mortality rates and prolonged morbidity seen in immunocompromised cohorts caused by opportunistic invasive infections as evidenced during HIV and COVID-19 pandemics. There is a need to develop real-time monitoring and diagnostic methods for fungal pathogens and to create a greater awareness as to the contribution of fungal pathogens in disease causation. Greater information is required on the appropriate selection and dose of antifungal drugs including factors governing resistance where there is commensurate need to discover more appropriate and effective solutions. Popular azole fungal drugs are widely detected in surface water and sediment due to incomplete removal in wastewater treatment plants where they are resistant to microbial degradation and may cause toxic effects on aquatic organisms such as algae and fish. UV has limited effectiveness in destruction of anti-fungal drugs where there is increased interest in the combination approaches such as novel use of pulsed-plasma gas-discharge technologies for environmental waste management. There is growing interest in developing alternative and complementary green eco-biocides and disinfection innovation. Fungi present challenges for cleaning, disinfection and sterilization of reusable medical devices such as endoscopes where they (example, Aspergillus and Candida species) can be protected when harboured in build-up biofilm from lethal processing. Information on the efficacy of established disinfection and sterilization technologies to address fungal pathogens including bottleneck areas that present high risk to patients is lacking. There is a need to address risk mitigation and modelling to inform efficacy of appropriate intervention technologies that must consider all contributing factors where there is potential to adopt digital technologies to enable real-time analysis of big data, such as use of artificial intelligence and machine learning. International consensus on standardised protocols for developing and reporting on appropriate alternative eco-solutions must be reached, particularly in order to address fungi with increasing drug resistance where research and innovation can be enabled using a One Health approach.
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Affiliation(s)
- Mary Garvey
- Department of Life Science, Atlantic Technological University, Sligo, Ireland; Centre for Precision Engineering, Materials and Manufacturing Research (PEM), Atlantic Technological University, Sligo, Ireland
| | - Elaine Meade
- Department of Life Science, Atlantic Technological University, Sligo, Ireland; Centre for Precision Engineering, Materials and Manufacturing Research (PEM), Atlantic Technological University, Sligo, Ireland
| | - Neil J Rowan
- Bioscience Research Institute, Technological University of the Shannon Midlands Midwest, Athlone, Ireland; Centre for Decontamination, Sterilization and Biosecurity, Technological University of the Shannon Midlands Midwest, Athlone, Ireland; Empower Eco Sustainability Hub, Technological University of the Shannon Midlands Midwest, Athlone, Ireland.
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21
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Rizzo M, Soisangwan N, Vega-Estevez S, Price RJ, Uyl C, Iracane E, Shaw M, Soetaert J, Selmecki A, Buscaino A. Stress combined with loss of the Candida albicans SUMO protease Ulp2 triggers selection of aneuploidy via a two-step process. PLoS Genet 2022; 18:e1010576. [PMID: 36574460 PMCID: PMC9829183 DOI: 10.1371/journal.pgen.1010576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 01/09/2023] [Accepted: 12/16/2022] [Indexed: 12/29/2022] Open
Abstract
A delicate balance between genome stability and instability ensures genome integrity while generating genetic diversity, a critical step for evolution. Indeed, while excessive genome instability is harmful, moderated genome instability can drive adaptation to novel environments by maximising genetic variation. Candida albicans, a human fungal pathogen that colonises different parts of the human body, adapts rapidly and frequently to different hostile host microenvironments. In this organism, the ability to generate large-scale genomic variation is a key adaptative mechanism triggering dangerous infections even in the presence of antifungal drugs. Understanding how fitter novel karyotypes are selected is key to determining how C. albicans and other microbial pathogens establish infections. Here, we identified the SUMO protease Ulp2 as a regulator of C. albicans genome integrity through genetic screening. Deletion of ULP2 leads to increased genome instability, enhanced genome variation and reduced fitness in the absence of additional stress. The combined stress caused by the lack of ULP2 and antifungal drug treatment leads to the selection of adaptive segmental aneuploidies that partially rescue the fitness defects of ulp2Δ/Δ cells. Short and long-read genomic sequencing demonstrates that these novel genotypes are selected via a two-step process leading to the formation of novel chromosomal fragments with breakpoints at microhomology regions and DNA repeats.
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Affiliation(s)
- Marzia Rizzo
- University of Kent, School of Biosciences, Kent Fungal Group, Canterbury Kent, United Kingdom
| | - Natthapon Soisangwan
- University of Minnesota, Department of Microbiology and Immunology, Minneapolis, Minnesota, United States of America
| | - Samuel Vega-Estevez
- University of Kent, School of Biosciences, Kent Fungal Group, Canterbury Kent, United Kingdom
| | | | - Chloe Uyl
- University of Kent, School of Biosciences, Kent Fungal Group, Canterbury Kent, United Kingdom
| | - Elise Iracane
- University of Kent, School of Biosciences, Kent Fungal Group, Canterbury Kent, United Kingdom
| | - Matt Shaw
- University of Kent, School of Biosciences, Kent Fungal Group, Canterbury Kent, United Kingdom
| | - Jan Soetaert
- Blizard Advanced Light Microscopy (BALM), Queen Mary University of London, United Kingdom
| | - Anna Selmecki
- University of Minnesota, Department of Microbiology and Immunology, Minneapolis, Minnesota, United States of America
| | - Alessia Buscaino
- University of Kent, School of Biosciences, Kent Fungal Group, Canterbury Kent, United Kingdom
- * E-mail:
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22
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Kamiński K, Hąc-Wydro K, Skóra M, Tymecka M, Obłoza M. Preliminary Studies on the Mechanism of Antifungal Activity of New Cationic β-Glucan Derivatives Obtained from Oats and Barley. ACS OMEGA 2022; 7:40333-40343. [PMID: 36385808 PMCID: PMC9648169 DOI: 10.1021/acsomega.2c05311] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
New chemical structures with antifungal properties are highly desirable from the point of view of modern pharmaceutical science, especially due to the increasingly widespread instances of drug resistance in the case of these diseases. One way to solve this problem is to use polymeric drugs, widely described as biocidal, positively charged macromolecules. In this work, we present the synthesis of new cationic β-glucan derivatives that show selective antifungal activity and at the same time low toxicity toward animal and human cells. Two β-glucans isolated from oats and barley and modified using glycidyltrimethylammonium chloride were obtained and evaluated for biocidal properties on the cells of mammals and pathogenic fungi and bacteria. These compounds were found to be nontoxic to fibroblast and bacterial cells but showed selective toxicity to certain species of filamentous fungi (Scopulariopsis brevicaulis) and yeasts (Cryptococcus neoformans). The most important aspect of this work is the attempt to explain the mechanisms of action of these compounds by studying their interaction with biological membranes. This was achieved by examining the interactions with model biological membranes representative of given families of microorganisms using Langmuir monolayers. The data obtained partly show correlations between the results for model systems and biological experiments and allow indicating that the selective antifungal activity of cationic β-glucans is related to their interaction with fungal biological membranes and partly lack of such interaction toward cells of other organisms. In addition, the obtained macromolecules were characterized by spectral methods (Fourier transform infrared (FTIR) and 1H nuclear magnetic resonance (NMR) spectroscopies) to confirm that the desired structure was obtained, and their degree of modification and molecular weights were determined.
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Affiliation(s)
- Kamil Kamiński
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2 Street, 30-387Kraków, Poland
| | - Katarzyna Hąc-Wydro
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2 Street, 30-387Kraków, Poland
| | - Magdalena Skóra
- Department
of Infections Control and Mycology, Chair of Microbiology, Jagiellonian University Medical College, Czysta 18 Street, 31-121Kraków, Poland
| | - Małgorzata Tymecka
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2 Street, 30-387Kraków, Poland
| | - Magdalena Obłoza
- Faculty
of Chemistry, Jagiellonian University, Gronostajowa 2 Street, 30-387Kraków, Poland
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23
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Wang Y, Xu F, Nichols CB, Shi Y, Hellinga HW, Alspaugh JA, Distefano MD, Beese LS. Structure-Guided Discovery of Potent Antifungals that Prevent Ras Signaling by Inhibiting Protein Farnesyltransferase. J Med Chem 2022; 65:13753-13770. [PMID: 36218371 PMCID: PMC10755971 DOI: 10.1021/acs.jmedchem.2c00902] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Infections by fungal pathogens are difficult to treat due to a paucity of antifungals and emerging resistances. Next-generation antifungals therefore are needed urgently. We have developed compounds that prevent farnesylation of Cryptoccoccus neoformans Ras protein by inhibiting protein farnesyltransferase with 3-4 nanomolar affinities. Farnesylation directs Ras to the cell membrane and is required for infectivity of this lethal pathogenic fungus. Our high-affinity compounds inhibit fungal growth with 3-6 micromolar minimum inhibitory concentrations (MICs), 4- to 8-fold better than Fluconazole, an antifungal commonly used in the clinic. Compounds bound with distinct inhibition mechanisms at two alternative, partially overlapping binding sites, accessed via different inhibitor conformations. We showed that antifungal potency depends critically on the selected inhibition mechanism because this determines the efficacy of an inhibitor at low in vivo levels of enzyme and farnesyl substrate. We elucidated how chemical modifications of the antifungals encode desired inhibitor conformation and concomitant inhibitory mechanism.
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Affiliation(s)
- You Wang
- Department of Biochemistry, Duke University School
of Medicine, Durham, North Carolina, USA 27710
| | - Feng Xu
- Department of Chemistry, University of Minnesota,
Minneapolis, Minnesota, USA 55455
| | - Connie B. Nichols
- Department of Medicine, Duke University School of
Medicine, Durham, North Carolina, USA 27710
- Department of Molecular Genetics and Microbiology,
Duke University School of Medicine, Durham, North Carolina, USA 27710
| | - Yuqian Shi
- Department of Biochemistry, Duke University School
of Medicine, Durham, North Carolina, USA 27710
| | - Homme W. Hellinga
- Department of Biochemistry, Duke University School
of Medicine, Durham, North Carolina, USA 27710
| | - J. Andrew Alspaugh
- Department of Medicine, Duke University School of
Medicine, Durham, North Carolina, USA 27710
- Department of Molecular Genetics and Microbiology,
Duke University School of Medicine, Durham, North Carolina, USA 27710
| | - Mark D. Distefano
- Department of Chemistry, University of Minnesota,
Minneapolis, Minnesota, USA 55455
| | - Lorena S. Beese
- Department of Biochemistry, Duke University School
of Medicine, Durham, North Carolina, USA 27710
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24
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Pratt EJ, Mancera-Andrade EI, Bicker KL. Synthesis and Characterization of Derivatives of the Antifungal Peptoid RMG8-8. ACS OMEGA 2022; 7:36663-36671. [PMID: 36278036 PMCID: PMC9583092 DOI: 10.1021/acsomega.2c04778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
Cryptococcal meningitis, caused by the fungal pathogen Cryptococcus neoformans, is a devastating disease with a mortality rate of over 80%. Due to the increasing prevalence of resistance to antifungals and the high mammalian toxicity of current treatments, the development of new antifungal therapies is vital. In an effort to improve the biological properties of a previously discovered antifungal peptoid, termed RMG8-8, an iterative structure-activity relationship study was conducted. This three-round study sought to optimize the structure of RMG8-8 by focusing on three main structural components: the lipophilic tail, aliphatic side chains, and aromatic side chains. In addition to antifungal testing against C. neoformans, cytotoxicity testing was also performed on all derivatives against human liver cells, and select promising compounds were tested for hemolytic activity against human red blood cells. A number of derivatives containing unique aliphatic or aromatic side chains had antifungal activity similar to RMG8-8 (MIC = 1.56 μg/mL), but all of these compounds were more toxic than RMG8-8. While no derivative was improved across all biological tests, modest improvements were made to the hemolytic activity with compound 9, containing isobutyl side chains in positions 2 and 5, compared to RMG8-8 (HC10 = 130 and 75 μg/mL, respectively). While this study did not yield a dramatically optimized RMG8-8 derivative, this result was not totally unexpected given the remarkable selectivity of this compound from discovery. Nonetheless, this study is an important step in the development of RMG8-8 as a viable antifungal therapeutic.
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25
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Matson MEH, Liang Q, Lonardi S, Judelson HS. Karyotype variation, spontaneous genome rearrangements affecting chemical insensitivity, and expression level polymorphisms in the plant pathogen Phytophthora infestans revealed using its first chromosome-scale assembly. PLoS Pathog 2022; 18:e1010869. [PMID: 36215336 PMCID: PMC9584435 DOI: 10.1371/journal.ppat.1010869] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 10/20/2022] [Accepted: 09/09/2022] [Indexed: 11/18/2022] Open
Abstract
Natural isolates of the potato and tomato pathogen Phytophthora infestans exhibit substantial variation in virulence, chemical sensitivity, ploidy, and other traits. A chromosome-scale assembly was developed to expand genomic resources for this oomyceteous microbe, and used to explore the basis of variation. Using PacBio and Illumina data, a long-range linking library, and an optical map, an assembly was created and coalesced into 15 pseudochromosomes spanning 219 Mb using SNP-based genetic linkage data. De novo gene prediction combined with transcript evidence identified 19,981 protein-coding genes, plus about eight thousand tRNA genes. The chromosomes were comprised of a mosaic of gene-rich and gene-sparse regions plus very long centromeres. Genes exhibited a biased distribution across chromosomes, especially members of families encoding RXLR and CRN effectors which clustered on certain chromosomes. Strikingly, half of F1 progeny of diploid parents were polyploid or aneuploid. Substantial expression level polymorphisms between strains were identified, much of which could be attributed to differences in chromosome dosage, transposable element insertions, and adjacency to repetitive DNA. QTL analysis identified a locus on the right arm of chromosome 3 governing sensitivity to the crop protection chemical metalaxyl. Strains heterozygous for resistance often experienced megabase-sized deletions of that part of the chromosome when cultured on metalaxyl, increasing resistance due to loss of the sensitive allele. This study sheds light on diverse phenomena affecting variation in P. infestans and relatives, helps explain the prevalence of polyploidy in natural populations, and provides a new foundation for biologic and genetic investigations.
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Affiliation(s)
- Michael E. H. Matson
- Department of Microbiology and Plant Pathology, University of California, Riverside, California, United States of America
| | - Qihua Liang
- Department of Computer Science and Engineering, University of California, Riverside, California, United States of America
| | - Stefano Lonardi
- Department of Computer Science and Engineering, University of California, Riverside, California, United States of America
| | - Howard S. Judelson
- Department of Microbiology and Plant Pathology, University of California, Riverside, California, United States of America
- * E-mail:
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26
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Handelman M, Osherov N. Experimental and in-host evolution of triazole resistance in human pathogenic fungi. FRONTIERS IN FUNGAL BIOLOGY 2022; 3:957577. [PMID: 37746192 PMCID: PMC10512370 DOI: 10.3389/ffunb.2022.957577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 07/19/2022] [Indexed: 09/26/2023]
Abstract
The leading fungal pathogens causing systemic infections in humans are Candida spp., Aspergillus fumigatus, and Cryptococcus neoformans. The major class of antifungals used to treat such infections are the triazoles, which target the cytochrome P450 lanosterol 14-α-demethylase, encoded by the ERG11 (yeasts)/cyp51A (molds) genes, catalyzing a key step in the ergosterol biosynthetic pathway. Triazole resistance in clinical fungi is a rising concern worldwide, causing increasing mortality in immunocompromised patients. This review describes the use of serial clinical isolates and in-vitro evolution toward understanding the mechanisms of triazole resistance. We outline, compare, and discuss how these approaches have helped identify the evolutionary pathways taken by pathogenic fungi to acquire triazole resistance. While they all share a core mechanism (mutation and overexpression of ERG11/cyp51A and efflux transporters), their timing and mechanism differs: Candida and Cryptococcus spp. exhibit resistance-conferring aneuploidies and copy number variants not seen in A. fumigatus. Candida spp. have a proclivity to develop resistance by undergoing mutations in transcription factors (TAC1, MRR1, PDR5) that increase the expression of efflux transporters. A. fumigatus is especially prone to accumulate resistance mutations in cyp51A early during the evolution of resistance. Recently, examination of serial clinical isolates and experimental lab-evolved triazole-resistant strains using modern omics and gene editing tools has begun to realize the full potential of these approaches. As a result, triazole-resistance mechanisms can now be analyzed at increasingly finer resolutions. This newfound knowledge will be instrumental in formulating new molecular approaches to fight the rapidly emerging epidemic of antifungal resistant fungi.
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Affiliation(s)
| | - Nir Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
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27
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Aguiar TKB, Neto NAS, Freitas CDT, Silva AFB, Bezerra LP, Malveira EA, Branco LAC, Mesquita FP, Goldman GH, Alencar LMR, Oliveira JTA, Santos-Oliveira R, Souza PFN. Antifungal Potential of Synthetic Peptides against Cryptococcus neoformans: Mechanism of Action Studies Reveal Synthetic Peptides Induce Membrane-Pore Formation, DNA Degradation, and Apoptosis. Pharmaceutics 2022; 14:pharmaceutics14081678. [PMID: 36015304 PMCID: PMC9416200 DOI: 10.3390/pharmaceutics14081678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 08/10/2022] [Accepted: 08/10/2022] [Indexed: 12/02/2022] Open
Abstract
Cryptococcus neoformans is a human-pathogenic yeast responsible for pneumonia and meningitis, mainly in patients immunocompromised. Infections caused by C. neoformans are a global health concern. Synthetic antimicrobial peptides (SAMPs) have emerged as alternative molecules to cope with fungal infections, including C. neoformans. Here, eight SAMPs were tested regarding their antifungal potential against C. neoformans and had their mechanisms of action elucidated by fluorescence and scanning electron microscopies. Five SAMPs showed an inhibitory effect (MIC50) on C. neoformans growth at low concentrations. Fluorescence microscope (FM) revealed that SAMPs induced 6-kDa pores in the C. neoformans membrane. Inhibitory assays in the presence of ergosterol revealed that some peptides lost their activity, suggesting interaction with it. Furthermore, FM analysis revealed that SAMPs induced caspase 3/7-mediated apoptosis and DNA degradation in C. neoformans cells. Scanning Electron Microscopy (SEM) analysis revealed that peptides induced many morphological alterations such as cell membrane, wall damage, and loss of internal content on C. neoformans cells. Our results strongly suggest synthetic peptides are potential alternative molecules to control C. neoformans growth and treat the cryptococcal infection.
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Affiliation(s)
- Tawanny K. B. Aguiar
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451-970, CE, Brazil
| | - Nilton A. S. Neto
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451-970, CE, Brazil
| | - Cleverson D. T. Freitas
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451-970, CE, Brazil
| | - Ayrles F. B. Silva
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451-970, CE, Brazil
| | - Leandro P. Bezerra
- Department of Fisheries Engineering, Federal University of Ceará, Fortaleza 60455-970, CE, Brazil
| | - Ellen A. Malveira
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451-970, CE, Brazil
| | - Levi A. C. Branco
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451-970, CE, Brazil
| | - Felipe P. Mesquita
- Drug Research and Development Center, Department of Physiology and Pharmacology, Federal University of Ceará, Fortaleza 60430-275, CE, Brazil
| | - Gustavo H. Goldman
- Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, São Paulo 14040-903, SP, Brazil
| | - Luciana M. R. Alencar
- Department of Physics, Laboratory of Biophysics and Nanosystems, Federal University of Maranhão, São Luís 65080-805, MA, Brazil
| | - Jose T. A. Oliveira
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451-970, CE, Brazil
| | - Ralph Santos-Oliveira
- Laboratory of Nanoradiopharmaceuticals and Radiopharmacy, Zona Oeste State University, Rio de Janeiro 23070-200, RJ, Brazil
- Brazilian Nuclear Energy Commission, Nuclear Engineering Institute, Rio de Janeiro 21941-906, RJ, Brazil
| | - Pedro F. N. Souza
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451-970, CE, Brazil
- Drug Research and Development Center, Department of Physiology and Pharmacology, Federal University of Ceará, Fortaleza 60430-275, CE, Brazil
- Correspondence:
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28
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Kassaza K, Wasswa F, Nielsen K, Bazira J. Cryptococcus neoformans Genotypic Diversity and Disease Outcome among HIV Patients in Africa. J Fungi (Basel) 2022; 8:jof8070734. [PMID: 35887489 PMCID: PMC9325144 DOI: 10.3390/jof8070734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 06/24/2022] [Accepted: 07/06/2022] [Indexed: 11/16/2022] Open
Abstract
Cryptococcal meningoencephalitis, a disease with poor patient outcomes, remains the most prevalent invasive fungal infection worldwide, accounting for approximately 180,000 deaths each year. In several areas of sub-Saharan Africa with the highest HIV prevalence, cryptococcal meningitis is the leading cause of community-acquired meningitis, with a high mortality among HIV-infected individuals. Recent studies show that patient disease outcomes are impacted by the genetics of the infecting isolate. Yet, there is still limited knowledge of how these genotypic variations contribute to clinical disease outcome. Further, it is unclear how the genetic heterogeneity of C. neoformans and the extensive phenotypic variation observed between and within isolates affects infection and disease. In this review, we discuss current knowledge of how various genotypes impact disease progression and patient outcome in HIV-positive populations in sub-Saharan African, a setting with a high burden of cryptococcosis.
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Affiliation(s)
- Kennedy Kassaza
- Department of Microbiology and Parasitology, Mbarara University of Science and Technology, Mbarara P.O. Box 1410, Uganda; (K.K.); (F.W.)
| | - Fredrickson Wasswa
- Department of Microbiology and Parasitology, Mbarara University of Science and Technology, Mbarara P.O. Box 1410, Uganda; (K.K.); (F.W.)
| | - Kirsten Nielsen
- Department of Microbiology and Immunology, University of Minnesota, Minneapolis, MN 55455, USA
- Correspondence: (K.N.); (J.B.)
| | - Joel Bazira
- Department of Microbiology and Parasitology, Mbarara University of Science and Technology, Mbarara P.O. Box 1410, Uganda; (K.K.); (F.W.)
- Correspondence: (K.N.); (J.B.)
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29
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Normile TG, Del Poeta M. Three Models of Vaccination Strategies Against Cryptococcosis in Immunocompromised Hosts Using Heat-Killed Cryptococcus neoformans Δ sgl1. Front Immunol 2022; 13:868523. [PMID: 35615354 PMCID: PMC9124966 DOI: 10.3389/fimmu.2022.868523] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 04/11/2022] [Indexed: 12/16/2022] Open
Abstract
Vaccines are one of the greatest medical accomplishments to date, yet no fungal vaccines are currently available in humans mainly because opportunistic mycoses generally occur during immunodeficiencies necessary for vaccine protection. In previous studies, a live, attenuated Cryptococcus neoformans Δsgl1 mutant accumulating sterylglucosides was found to be avirulent and protected mice from a subsequent lethal infection even in absence of CD4+ T cells, a condition most associated with cryptococcosis (e.g., HIV). Here, we tested three strategies of vaccination against cryptococcosis. First, in our preventative model, protection was achieved even after a 3-fold increase of the vaccination window. Second, because live C. neoformans Δsgl1-vaccinated mice challenged more than once with WT strain had a significant decrease in lung fungal burden, we tested C. neoformans Δsgl1 as an immunotherapeutic. We found that therapeutic administrations of HK C. neoformans Δsgl1 post WT challenge significantly improves the lung fungal burden. Similarly, therapeutic administration of HK C. neoformans Δsgl1 post WT challenge resulted in 100% or 70% survival depending on the time of vaccine administration, suggesting that HK Δsgl1 is a robust immunotherapeutic option. Third, we investigated a novel model of vaccination in preventing reactivation from lung granuloma using C. neoformans Δgcs1. Remarkably, we show that administration of HK Δsgl1 prevents mice from reactivating Δgcs1 upon inducing immunosuppression with corticosteroids or by depleting CD4+ T cells. Our results suggest that HK Δsgl1 represents a clinically relevant, efficacious vaccine that confers robust host protection in three models of vaccination against cryptococcosis even during CD4-deficiency.
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Affiliation(s)
- Tyler G. Normile
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, NY, United States
| | - Maurizio Del Poeta
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, NY, United States,Division of Infectious Diseases, School of Medicine, Stony Brook University, Stony Brook, NY, United States,Veterans Administration Medical Center, Northport, NY, United States,*Correspondence: Maurizio Del Poeta,
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30
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Lineages Derived from Cryptococcus neoformans Type Strain H99 Support a Link between the Capacity to Be Pleomorphic and Virulence. mBio 2022; 13:e0028322. [PMID: 35258331 PMCID: PMC9040854 DOI: 10.1128/mbio.00283-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The pathogenic yeast Cryptococcus neoformans causes nearly 200,000 deaths annually in immunocompromised individuals. Cryptococcus cells can undergo substantial morphological change during mammalian infection, including increased capsule and cell size, the release of shed capsule, and the production of titan (>10 μm), micro (<2 μm)-, and irregular cells. We examined phenotypic variation under conditions designed to simulate in vivo stress in a collection of nine lineages derived from the C. neoformans type strain H99. These lineages are highly genetically similar but have a range of virulence levels. Strains from hypervirulent lineages had a larger average capsule size, greater variation in cell size, and an increased production of microcells and shed capsule. We tested whether disruption of SGF29, which encodes a component of the SAGA histone acetylation complex that has previously been implicated in the hypervirulence of some lineages, also has a role in the production of morphological variants. Deletion of SGF29 in a lineage with intermediate virulence substantially increased its production of microcells and released capsule, consistent with a switch to hypervirulence. We further examined SGF29 in a set of 52 clinical isolates and found loss-of-function mutations were significantly correlated with patient death. Expansion of a TA repeat in the second intron of SGF29 was positively correlated with cell and capsule size, suggesting it also affects Sgf29 function. This study extends the evidence for a link between pleomorphism and virulence in Cryptococcus, with a likely role for epigenetic mechanisms mediated by SAGA-induced histone acetylation.
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The Cyclin Cln1 Controls Polyploid Titan Cell Formation following a Stress-Induced G 2 Arrest in Cryptococcus. mBio 2021; 12:e0250921. [PMID: 34634930 PMCID: PMC8510536 DOI: 10.1128/mbio.02509-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The pathogenic yeast Cryptococcus neoformans produces polyploid titan cells in response to the host lung environment that are critical for host adaptation and subsequent disease. We analyzed the in vivo and in vitro cell cycles to identify key aspects of the C. neoformans cell cycle that are important for the formation of titan cells. We identified unbudded 2C cells, referred to as a G2 arrest, produced both in vivo and in vitro in response to various stresses. Deletion of the nonessential cyclin Cln1 resulted in overproduction of titan cells in vivo and transient morphology defects upon release from stationary phase in vitro. Using a copper-repressible promoter PCTR4-CLN1 strain and a two-step in vitro titan cell formation assay, our in vitro studies revealed Cln1 functions after the G2 arrest. These studies highlight unique cell cycle alterations in C. neoformans that ultimately promote genomic diversity and virulence in this important fungal pathogen.
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Accounting for the Biological Complexity of Pathogenic Fungi in Phylogenetic Dating. J Fungi (Basel) 2021; 7:jof7080661. [PMID: 34436200 PMCID: PMC8400180 DOI: 10.3390/jof7080661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 08/11/2021] [Accepted: 08/11/2021] [Indexed: 11/17/2022] Open
Abstract
In the study of pathogen evolution, temporal dating of phylogenies provides information on when species and lineages may have diverged in the past. When combined with spatial and epidemiological data in phylodynamic models, these dated phylogenies can also help infer where and when outbreaks occurred, how pathogens may have spread to new geographic locations and/or niches, and how virulence or drug resistance has developed over time. Although widely applied to viruses and, increasingly, to bacterial pathogen outbreaks, phylogenetic dating is yet to be widely used in the study of pathogenic fungi. Fungi are complex organisms with several biological processes that could present issues with appropriate inference of phylogenies, clock rates, and divergence times, including high levels of recombination and slower mutation rates although with potentially high levels of mutation rate variation. Here, we discuss some of the key methodological challenges in accurate phylogeny reconstruction for fungi in the context of the temporal analyses conducted to date and make recommendations for future dating studies to aid development of a best practices roadmap in light of the increasing threat of fungal outbreaks and antifungal drug resistance worldwide.
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Yamamura D, Xu J. Update on Pulmonary Cryptococcosis. Mycopathologia 2021; 186:717-728. [PMID: 34181160 DOI: 10.1007/s11046-021-00575-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Accepted: 06/22/2021] [Indexed: 12/24/2022]
Abstract
Pulmonary cryptococcosis is a common but underdiagnosed opportunistic fungal infection in both immunocompromised and immunocompetent patients. The causal agents include at least eight evolutionary distinct haploid lineages as well as their hybrids of the human pathogenic Cryptococcus complex. In this update, we review recent advances in epidemiology, mode of transmission, risk factors, diagnostic methods, and therapy of pulmonary cryptococcosis. Our review suggests significant challenges and opportunities for research, from bedside to benchside and back to bedside.
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Affiliation(s)
- Deborah Yamamura
- Microbiology Department, Hamilton Regional Laboratory Medicine Program, Hamilton General Hospital, Hamilton, ON, L8L 2X2, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, L8S 4K1, Canada
| | - Jianping Xu
- Department of Biology, McMaster University, Hamilton, L8S 4K1, Canada.
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Donlin MJ, Lane TR, Riabova O, Lepioshkin A, Xu E, Lin J, Makarov V, Ekins S. Discovery of 5-Nitro-6-thiocyanatopyrimidines as Inhibitors of Cryptococcus neoformans and Cryptococcus gattii. ACS Med Chem Lett 2021; 12:774-781. [PMID: 34055225 DOI: 10.1021/acsmedchemlett.1c00038] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/31/2021] [Indexed: 12/27/2022] Open
Abstract
Opportunistic infections from pathogenic fungi present a major challenge to healthcare because of a very limited arsenal of antifungal drugs, an increasing population of immunosuppressed patients, and increased prevalence of resistant clinical strains due to overuse of the few available antifungals. Cryptococcal meningitis is a life-threatening opportunistic fungal infection caused by one of two species in the Cryptococcus genus, Cryptococcus neoformans and Cryptococcus gattii. Eighty percent of cryptococcosis diseases are caused by C. neoformans that is endemic in the environment. The standard of care is limited to old antifungals, and under a high standard of care, mortality remains between 10 and 30%. We have identified a series of 5-nitro-6-thiocyanatopyrimidine antifungal drug candidates using in vitro and computational machine learning approaches. These compounds can inhibit C. neoformans growth at submicromolar levels, are effective against fluconazole-resistant C. neoformans and a clinical strain of C. gattii, and are not antagonistic with currently approved antifungals.
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Affiliation(s)
- Maureen J. Donlin
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, United States
- Institute for Drug and Biotherapeutic Development, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Thomas R. Lane
- Collaborations Pharmaceuticals, Inc., Raleigh, North Carolina 27606, United States
| | - Olga Riabova
- Department of Biology, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Alexander Lepioshkin
- Department of Biology, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Evan Xu
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, Missouri 63104, United States
| | - Jeffrey Lin
- Department of Biology, Saint Louis University, St. Louis, Missouri 63103, United States
| | - Vadim Makarov
- Research Center of Biotechnology RAS, 119071 Moscow, Russia
| | - Sean Ekins
- Collaborations Pharmaceuticals, Inc., Raleigh, North Carolina 27606, United States
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Stovall AK, Knowles CM, Kalem MC, Panepinto JC. A Conserved Gcn2-Gcn4 Axis Links Methionine Utilization and the Oxidative Stress Response in Cryptococcus neoformans. FRONTIERS IN FUNGAL BIOLOGY 2021; 2:640678. [PMID: 34622246 PMCID: PMC8494424 DOI: 10.3389/ffunb.2021.640678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 03/01/2021] [Indexed: 11/13/2022]
Abstract
The fungal pathogen Cryptococcus neoformans relies on post-transcriptional mechanisms of gene regulation to adapt to stressors it encounters in the human host, such as oxidative stress and nutrient limitation. The kinase Gcn2 regulates translation in response to stress by phosphorylating the initiation factor eIF2, and it is a crucial factor in withstanding oxidative stress in C. neoformans, and amino acid limitation in many fungal species. However, little is known about the role of Gcn2 in nitrogen limitation in C. neoformans. In this study, we demonstrate that Gcn2 is required for C. neoformans to utilize methionine as a source of nitrogen, and that the presence of methionine as a sole nitrogen source induces eIF2 phosphorylation. The stress imposed by methionine leads to an oxidative stress response at both the levels of transcription and translation, as seen through polysome profiling as well as increased abundance of select oxidative stress response transcripts. The transcription factor Gcn4 is also required for methionine utilization and oxidative stress resistance, and RT-qPCR data suggests that it regulates expression of certain transcripts in response to oxidative stress. The results of this study suggest a connection between nitrogen metabolism and oxidative stress in C. neoformans that is mediated by Gcn4, possibly indicating the presence of a compound stress response in this clinically important fungal pathogen.
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Affiliation(s)
| | | | | | - John C. Panepinto
- Department of Microbiology and Immunology, Witebsky Center for Microbial Pathogenesis and Immunology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York (SUNY), Buffalo, NY, United States
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Treatment strategies for cryptococcal infection: challenges, advances and future outlook. Nat Rev Microbiol 2021; 19:454-466. [PMID: 33558691 PMCID: PMC7868659 DOI: 10.1038/s41579-021-00511-0] [Citation(s) in RCA: 135] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/07/2021] [Indexed: 01/31/2023]
Abstract
Cryptococcus spp., in particular Cryptococcus neoformans and Cryptococcus gattii, have an enormous impact on human health worldwide. The global burden of cryptococcal meningitis is almost a quarter of a million cases and 181,000 deaths annually, with mortality rates of 100% if infections remain untreated. Despite these alarming statistics, treatment options for cryptococcosis remain limited, with only three major classes of drugs approved for clinical use. Exacerbating the public health burden is the fact that the only new class of antifungal drugs developed in decades, the echinocandins, displays negligible antifungal activity against Cryptococcus spp., and the efficacy of the remaining therapeutics is hampered by host toxicity and pathogen resistance. Here, we describe the current arsenal of antifungal agents and the treatment strategies employed to manage cryptococcal disease. We further elaborate on the recent advances in our understanding of the intrinsic and adaptive resistance mechanisms that are utilized by Cryptococcus spp. to evade therapeutic treatments. Finally, we review potential therapeutic strategies, including combination therapy, the targeting of virulence traits, impairing stress response pathways and modulating host immunity, to effectively treat infections caused by Cryptococcus spp. Overall, understanding of the mechanisms that regulate anti-cryptococcal drug resistance, coupled with advances in genomics technologies and high-throughput screening methodologies, will catalyse innovation and accelerate antifungal drug discovery.
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Tian B, Liu Y, Liu J. Smart stimuli-responsive drug delivery systems based on cyclodextrin: A review. Carbohydr Polym 2020; 251:116871. [PMID: 33142550 DOI: 10.1016/j.carbpol.2020.116871] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 07/29/2020] [Accepted: 07/30/2020] [Indexed: 12/29/2022]
Abstract
Stimulated by researches in materials chemistry and medicine fields, drug delivery has entered a new stage of development. Drug delivery systems have been extensively studied according to the differences in the drug therapeutic environment such as pH, light, temperature, magnet, redox, enzymes, etc. Cyclodextrin is a smart tool that has been proven to be used in the preparation of drug delivery, and has become a new area of concern in recent years. In this review, we discuss recent research advances in smart stimuli-responsive cyclodextrin-based drug delivery. First, different stimuli-responsive drug delivery systems based on cyclodextrin are introduced and classified. Then, the characteristics of different types of stimuli-responsive drug delivery systems are described, and their applications are emphasized. Finally, current challenges and future development opportunities of smart stimuli-responsive drug delivery systems based on cyclodextrin are discussed.
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Affiliation(s)
- Bingren Tian
- College of Chemistry and Chemical Engineering, Xinjiang University, Urumchi, 830001, China.
| | - Yumei Liu
- College of Chemistry and Chemical Engineering, Xinjiang University, Urumchi, 830001, China.
| | - Jiayue Liu
- School of Pharmacy, Ningxia Medical University, Yinchuan, 750004, China.
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Ballou ER. mSphere of Influence: Positive Research Culture Enables Excellence and Innovation. mSphere 2020; 5:5/1/e00948-19. [PMID: 31941817 PMCID: PMC6968658 DOI: 10.1128/msphere.00948-19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Elizabeth Ballou works in the field of medical mycology. In this mSphere of Influence article, she reflects on how two papers by Okagaki et al. (PLoS Pathog 6:e1000953, 2010, https://doi.org/10.1371/journal.ppat.1000953) and Zaragoza et al. (PLoS Pathog 6:e1000945, 2010, https://doi.org/10.1371/journal.ppat.1000945) made an impact on her career by demonstrating an alternative to destructive publication practices.
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Affiliation(s)
- Elizabeth R Ballou
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, Birmingham, United Kingdom
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