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Görlitz K, Bessler L, Helm M, Schaffrath R, Klassen R. Fluoropyrimidines trigger decay of hypomodified tRNA in yeast. Nucleic Acids Res 2024; 52:5841-5851. [PMID: 38716877 PMCID: PMC11162795 DOI: 10.1093/nar/gkae341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 04/10/2024] [Accepted: 04/22/2024] [Indexed: 06/11/2024] Open
Abstract
Therapeutic fluoropyrimidines 5-fluorouracil (5-FU) and 5-fluorocytosine (5-FC) are in long use for treatment of human cancers and severe invasive fungal infections, respectively. 5-Fluorouridine triphosphate represents a bioactive metabolite of both drugs and is incorporated into target cells' RNA. Here we use the model fungus Saccharomyces cerevisiae to define fluorinated tRNA as a key mediator of 5-FU and 5-FC cytotoxicity when specific tRNA methylations are absent. tRNA methylation deficiency caused by loss of Trm4 and Trm8 was previously shown to trigger an RNA quality control mechanism resulting in partial destabilization of hypomodified tRNAValAAC. We demonstrate that, following incorporation into tRNA, fluoropyrimidines strongly enhance degradation of yeast tRNAValAAC lacking Trm4 and Trm8 dependent methylations. At elevated temperature, such effect occurs already in absence of Trm8 alone. Genetic approaches and quantification of tRNA modification levels reveal that enhanced fluoropyrimidine cytotoxicity results from additional, drug induced uridine modification loss and activation of tRNAValAAC decay involving the exonuclease Xrn1. These results suggest that inhibition of tRNA methylation may be exploited to boost therapeutic efficiency of 5-FU and 5-FC.
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Affiliation(s)
- Katharina Görlitz
- Institute of Biology, Department of Microbiology, Universität Kassel, Kassel 34132, Germany
| | - Larissa Bessler
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-Universität Mainz, Mainz 55128, Germany
| | - Mark Helm
- Institute of Pharmaceutical and Biomedical Sciences, Johannes Gutenberg-Universität Mainz, Mainz 55128, Germany
| | - Raffael Schaffrath
- Institute of Biology, Department of Microbiology, Universität Kassel, Kassel 34132, Germany
| | - Roland Klassen
- Institute of Biology, Department of Microbiology, Universität Kassel, Kassel 34132, Germany
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Kanagavel M, Sparjan Samuvel RM, Ramalingam V, Nechipadappu SK. Repurposing of Antifungal Drug Flucytosine/Flucytosine Cocrystals for Anticancer Activity against Prostate Cancer Targeting Apoptosis and Inflammatory Signaling Pathways. Mol Pharm 2024; 21:2577-2589. [PMID: 38647021 DOI: 10.1021/acs.molpharmaceut.4c00156] [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] [Indexed: 04/25/2024]
Abstract
This study aimed to repurpose the antifungal drug flucytosine (FCN) for anticancer activity together with cocrystals of nutraceutical coformers sinapic acid (SNP) and syringic acid (SYA). The cocrystal screening experiments with SNP resulted in three cocrystal hydrate forms in which two are polymorphs, namely, FCN-SNP F-I and FCN-SNP F-II, and the third one with different stoichiometry in the asymmetric unit (1:2:1 ratio of FCN:SNP:H2O, FCN-SNP F-III). Cocrystallization with SYA resulted in two hydrated cocrystal polymorphs, namely, FCN-SYA F-I and FCN-SYA F-II. All the cocrystal polymorphs were obtained concomitantly during the slow evaporation method, and one of the polymorphs of each system was produced in bulk by the slurry method. The interaction energy and lattice energies of all cocrystal polymorphs were established using solid-state DFT calculations, and the outcomes correlated with the experimental results. Further, the in vitro cytotoxic activity of the cocrystals was determined against DU145 prostate cancer and the results showed that the FCN-based cocrystals (FCN-SNP F-III and FCN-SYA F-I) have excellent growth inhibitory activity at lower concentrations compared with parent FCN molecules. The prepared cocrystals induce apoptosis by generating oxidative stress and causing nuclear damage in prostate cancer cells. The Western blot analysis also depicted that the cocrystals downregulate the inflammatory markers such as NLRP3 and caspase-1 and upregulate the intrinsic apoptosis signaling pathway marker proteins, such as Bax, p53, and caspase-3. These findings suggest that the antifungal drug FCN can be repurposed for anticancer activity.
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Affiliation(s)
- Manimurugan Kanagavel
- Centre for X-ray Crystallography, Department of Analytical & Structural Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Rajan Marystella Sparjan Samuvel
- Department of Natural Products and Medicinal Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Vaikundamoorthy Ramalingam
- Department of Natural Products and Medicinal Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sunil Kumar Nechipadappu
- Centre for X-ray Crystallography, Department of Analytical & Structural Chemistry, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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Coelho RA, Almeida-Silva F, Figueiredo-Carvalho MHG, Rabello VBDS, de Souza GR, Lourenço MCDS, Rodrigues ML, Almeida-Paes R. Comparison of the antifungal activity of the pyrimidine analogs flucytosine and carmofur against human-pathogenic dematiaceous fungi. Med Mycol 2024; 62:myae029. [PMID: 38533658 PMCID: PMC11008743 DOI: 10.1093/mmy/myae029] [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: 11/28/2023] [Revised: 03/07/2024] [Accepted: 03/25/2024] [Indexed: 03/28/2024] Open
Abstract
Chromoblastomycosis (CBM) and pheohyphomycosis (PHM) are the most common implantation mycoses caused by dematiaceous fungi. In the past, flucytosine (5-FC) has been used to treat CBM, but development of resistance is common. Carmofur belongs to the same class as 5-FC and has in vitro inhibitory activity against the main agents of CBM and PHM. The aim of this study was to compare the action of these two pyrimidine analog drugs against CBM and PHM agents. The minimum inhibitory concentration (MIC) and the selectivity index based on cytotoxicity tests of these two drugs against some agents of these mycoses were determined, with carmofur presenting a higher selectivity index than 5-FC. Carmofur demonstrated here synergistic interactions with itraconazole and amphotericin B against Exophiala heteromorpha, Fonsecaea pedrosoi, Fonsecaea monophora, and Fonsecaea nubica strains. Additionally, carmofur plus itraconazole demonstrated here synergism against a Phialophora verrucosa strain. To evaluate the development of carmofur resistance, passages in culture medium containing subinhibitory concentrations of this pyrimidine analog were carried out, followed by in vitro susceptibility tests. Exophiala dermatitidis quickly developed resistance, whereas F. pedrosoi took seven passages in carmofur-supplemented medium to develop resistance. Moreover, resistance was permanent in E. dermatitidis but transient in F. pedrosoi. Hence, carmofur has exhibited certain advantages, albeit accompanied by limitations such as the development of resistance, which was expected as with 5-FC. This underscores its therapeutic potential in combination with other drugs, emphasizing the need for a meticulous evaluation of its application in the fight against dematiaceous fungi.
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Affiliation(s)
- Rowena Alves Coelho
- Mycology Laboratory, National Institute of Infectious Diseases Evandro Chagas, INI/Fiocruz, Rio de Janeiro, Brazil
| | - Fernando Almeida-Silva
- Mycology Laboratory, National Institute of Infectious Diseases Evandro Chagas, INI/Fiocruz, Rio de Janeiro, Brazil
| | | | | | - Gabriela Rodrigues de Souza
- RPT 11B Bioassay Platform, National Institute of Infectious Diseases Evandro Chagas, INI/Fiocruz, Rio de Janeiro, Brazil
| | | | - Marcio L Rodrigues
- Carlos Chagas Institute, Fiocruz, Paraná, Brazil
- Institute of Microbiology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Rodrigo Almeida-Paes
- Mycology Laboratory, National Institute of Infectious Diseases Evandro Chagas, INI/Fiocruz, Rio de Janeiro, Brazil
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Yoo K, Oliveira NK, Bhattacharya S, Fries BC. Achieving Resilience in Aging: How Mitochondrial Modulation Drives Age-associated Fluconazole Tolerance in Cryptococcus neoformans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.26.586817. [PMID: 38585804 PMCID: PMC10996610 DOI: 10.1101/2024.03.26.586817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Cryptococcus neoformans ( Cn ) is an opportunistic fungal microorganism that causes life-threatening meningoencephalitis. During the infection, the microbial population is heterogeneously composed of cells with varying generational ages, with older cells accumulating during chronic infections. This is attributed to their enhanced resistance to phagocytic killing and tolerance of antifungals like fluconazole (FLC). In this study, we investigated the role of ergosterol synthesis, ATP-binding cassette (ABC) transporters, and mitochondrial metabolism in the regulation of age-dependent FLC tolerance. We find that old Cn cells increase the production of ergosterol and exhibit upregulation of ABC transporters. Old cells also show transcriptional and phenotypic characteristics consistent with increased metabolic activity, leading to increased ATP production. This is accompanied by increased production of reactive oxygen species (ROS), which results in mitochondrial fragmentation. This study demonstrates that the metabolic changes occurring in the mitochondria of old cells drive the increase in ergosterol synthesis and the upregulation of ABC transporters, leading to FLC tolerance. IMPORTANCE Infections caused by Cryptococcus neoformans cause more than 180,000 deaths annually. Estimated one-year mortality for patients receiving care ranges from 20% in developed countries to 70% in developing countries, suggesting that current treatments are inadequate. Some fungal cells can persist and replicate despite the usage of current antifungal regimens, leading to death or treatment failure. In replicative aging, older cells display a resilient phenotype, characterized by their enhanced tolerance against antifungals and resistance to killing by host cells. This study shows that age-dependent increase in mitochondrial reactive oxygen species drive changes in ABC transporters and ergosterol synthesis, ultimately leading to the heightened tolerance against fluconazole in old C. neoformans cells. Understanding the underlying molecular mechanisms of this age-associated antifungal tolerance will enable more targeted antifungal therapies for cryptococcal infections.
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Aguiar TK, Costa AC, Neto NA, Brito DM, Freitas CD, Neto JM, Mesquita FP, Souza PF. Rise and fall of Caspofungin: the current status of Caspofungin as a treatment for Cryptococcus neoformans infection. Future Microbiol 2024. [PMID: 38497911 DOI: 10.2217/fmb-2023-0236] [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] [Indexed: 03/19/2024] Open
Abstract
Antifungal infections are becoming a major concern to human health due to antimicrobial resistance. Echinocandins have been promising agents against resistant fungal infections, primarily caspofungin, which has a more effective mechanism of action than azoles and polyenes. However, fungi such as Cryptococcus neoformans appear to be inheritably resistant to these drugs, which is concerning due to the high clinical importance of C. neoformans. In this review, we review the history of C. neoformans and the treatments used to treat antifungals over the years, focusing on caspofungin, while highlighting the C. neoformans problem and possible explanations for its inherent resistance.
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Affiliation(s)
- Tawanny Kb Aguiar
- Department of Biochemistry & Molecular Biology, Federal University of Ceará, Fortaleza, CE, 60451-970, Brazil
| | - Ana Cm Costa
- Department of Biochemistry & Molecular Biology, Federal University of Ceará, Fortaleza, CE, 60451-970, Brazil
| | - Nilton As Neto
- University of Brasília, Post-Graduation in Molecular Pathology, Darcy Ribeiro Campus, Brasília, DF, 70910-900, Brazil
| | - Daiane Ms Brito
- Department of Biochemistry & Molecular Biology, Federal University of Ceará, Fortaleza, CE, 60451-970, Brazil
- Drug Research & Development Center, Department of Physiology & Pharmacology, Federal University of Ceará, Fortaleza, CE, 60430-275, Brazil
| | - Cleverson Dt Freitas
- Department of Biochemistry & Molecular Biology, Federal University of Ceará, Fortaleza, CE, 60451-970, Brazil
| | - João Mm Neto
- Department of Biochemistry & Molecular Biology, Federal University of Ceará, Fortaleza, CE, 60451-970, Brazil
| | - Felipe P Mesquita
- Drug Research & Development Center, Department of Physiology & Pharmacology, Federal University of Ceará, Fortaleza, CE, 60430-275, Brazil
| | - Pedro Fn Souza
- Drug Research & Development Center, Department of Physiology & Pharmacology, Federal University of Ceará, Fortaleza, CE, 60430-275, Brazil
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Minja M, Mbilinyi T, Mkinga B, Philipo EG, Owenya J, Kilonzi M. Prevalence, treatment, and factors associated with cryptococcal meningitis post introduction of integrase inhibitors antiretroviral based regimens among People Living with HIV in Tanzania. PLoS One 2024; 19:e0294940. [PMID: 38412200 PMCID: PMC10898767 DOI: 10.1371/journal.pone.0294940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 01/12/2024] [Indexed: 02/29/2024] Open
Abstract
OBJECTIVE This study aimed to assess the prevalence of Cryptococcal Meningitis (CM), treatment practice, and the associated factors post-introduction of Tenofovir Lamivudine and Dolutegravir (TLD) regimen among People Living with HIV (PLHIV) in Tanzania. METHODS This was an analytical cross-sectional study, and the data was collected retrospectively in three public regional referral hospitals (RRHs) in Dar es Salaam, Tanzania. A total of 405 files of the PLHIV admitted in the medical wards on the TLD regimen from January 2019 to December 2022 were reviewed. The collected information includes the patient's demographic characteristics, Cryptococcal status, CD4 level at the time of CM diagnosis, status of using ART, CM treatment approach, and outcome. Data was analyzed using SPSS software version 23. RESULTS Out of 405 patients, the majority 267(65.9%) were female, 224(55.3%) were aged between 36-55 years, and 293(72.3%) were married. ART defaulters were found to be 37(9.1%). The prevalence of CM was found to be 48(11.9%), out of which 42(87.5%) received fluconazole alone. ART defaulter and marital status significantly (p-value < 0.05) were associated with those who tested CM positive. CONCLUSION The study found the prevalence of CM among PLHIV to be significantly high and the majority were treated with fluconazole alone. ART defaulters and marital status were significantly associated with one being CM positive. Responsible authorities and stakeholders should enforce guideline adherence and PLHIV should be encouraged on medication adherence.
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Affiliation(s)
- Makyao Minja
- Department of Clinical Pharmacy and Pharmacology, School of Pharmacy, The Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Tusaligwe Mbilinyi
- Department of Pharmaceutical Microbiology, School of Pharmacy, The Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Bryceson Mkinga
- Department of Pharmacognosy, School of Pharmacy, The Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Erick G Philipo
- Department of Pharmaceutics and Pharmacy Practice, School of Pharmacy, The Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Joyce Owenya
- Department of Pharmacy, Temeke Regional Referral Hospital, Dar es Salaam, Tanzania
| | - Manase Kilonzi
- Department of Clinical Pharmacy and Pharmacology, School of Pharmacy, The Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
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Meng Y, Ni Y, Li Z, Jiang T, Sun T, Li Y, Gao X, Li H, Suo C, Li C, Yang S, Lan T, Liao G, Liu T, Wang P, Ding C. Interplay between acetylation and ubiquitination of imitation switch chromatin remodeler Isw1 confers multidrug resistance in Cryptococcus neoformans. eLife 2024; 13:e85728. [PMID: 38251723 PMCID: PMC10834027 DOI: 10.7554/elife.85728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 01/21/2024] [Indexed: 01/23/2024] Open
Abstract
Cryptococcus neoformans poses a threat to human health, but anticryptococcal therapy is hampered by the emergence of drug resistance, whose underlying mechanisms remain poorly understood. Herein, we discovered that Isw1, an imitation switch chromatin remodeling ATPase, functions as a master modulator of genes responsible for in vivo and in vitro multidrug resistance in C. neoformans. Cells with the disrupted ISW1 gene exhibited profound resistance to multiple antifungal drugs. Mass spectrometry analysis revealed that Isw1 is both acetylated and ubiquitinated, suggesting that an interplay between these two modification events exists to govern Isw1 function. Mutagenesis studies of acetylation and ubiquitination sites revealed that the acetylation status of Isw1K97 coordinates with its ubiquitination processes at Isw1K113 and Isw1K441 through modulating the interaction between Isw1 and Cdc4, an E3 ligase. Additionally, clinical isolates of C. neoformans overexpressing the degradation-resistant ISW1K97Q allele showed impaired drug-resistant phenotypes. Collectively, our studies revealed a sophisticated acetylation-Isw1-ubiquitination regulation axis that controls multidrug resistance in C. neoformans.
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Affiliation(s)
- Yang Meng
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Yue Ni
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Zhuoran Li
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Tianhang Jiang
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Tianshu Sun
- Department of Scientific Research, Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina
| | - Yanjian Li
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Xindi Gao
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Hailong Li
- NHC Key Laboratory of AIDS Immunology, The First Affiliated Hospital of China Medical UniversityShenyangChina
| | - Chenhao Suo
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Chao Li
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Sheng Yang
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Tian Lan
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
| | - Guojian Liao
- College of Pharmaceutical Sciences, Southwest UniversityChongqingChina
| | - Tongbao Liu
- Medical Research Institute, Southwest UniversityChongqingChina
| | - Ping Wang
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center New OrleansNew OrleansUnited States
| | - Chen Ding
- College of Life and Health Sciences, Northeastern UniversityShenyangChina
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8
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Aderibigbe BA. Nanotherapeutics for the delivery of antifungal drugs. Ther Deliv 2024. [PMID: 38174574 DOI: 10.4155/tde-2023-0090] [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] [Indexed: 01/05/2024] Open
Abstract
The treatment of fungal infections is challenging with high death rates reported among immunocompromised patients. The currently available antifungals suffer from poor bioavailability and solubility, pharmacokinetics, and drug resistance, with limited cellular uptake. The clinical pipeline of new antifungals is dry. The incorporation of antifungal drugs into polymer-based nanocarriers to form nanotherapeutics is a promising approach to enhance the therapeutic outcomes of the available antifungal drugs. This review summarizes different polymer-based nanotherapeutics strategies that have been explored for the delivery of antifungals, resulting in enhanced therapeutic outcomes, such as improved pharmacokinetics, targeted/sustained delivery, prolonged drug circulation, retention of the drugs at the localized site of action, and overcoming drug resistance when compared with the free antifungal drugs.
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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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10
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Lanser DM, Bennett AB, Vu K, Gelli A. Macropinocytosis as a potential mechanism driving neurotropism of Cryptococcus neoformans. Front Cell Infect Microbiol 2023; 13:1331429. [PMID: 38149006 PMCID: PMC10750359 DOI: 10.3389/fcimb.2023.1331429] [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: 11/01/2023] [Accepted: 11/27/2023] [Indexed: 12/28/2023] Open
Abstract
Cryptococcus neoformans can invade the central nervous system by crossing the blood-brain barrier via a transcellular mechanism that relies on multiple host factors. In this narrative, we review the evidence that a direct interplay between C. neoformans and brain endothelial cells forms the basis for invasion and transmigration across the brain endothelium. Adherence and internalization of C. neoformans is dependent on transmembrane proteins, including a hyaluronic acid receptor and an ephrin receptor tyrosine kinase. We consider the role of EphA2 in facilitating the invasion of the central nervous system by C. neoformans and highlight experimental evidence supporting macropinocytosis as a potential mechanism of internalization and transcytosis. How macropinocytosis might be conclusively demonstrated in the context of C. neoformans is also discussed.
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Affiliation(s)
| | | | | | - Angie Gelli
- Department of Pharmacology, School of Medicine, University of California, Davis, Davis, CA, United States
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11
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Gangadharan SS, Raveendranath S. Cryptococcosis in oncology patients: a case series in a tertiary care cancer centre. IRANIAN JOURNAL OF MICROBIOLOGY 2023; 15:821-825. [PMID: 38156297 PMCID: PMC10751610 DOI: 10.18502/ijm.v15i6.14163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/30/2023]
Abstract
Cryptococcosis, a relatively uncommon infection in cancer patients is often associated with delayed diagnosis and high fatality rate due to its highly heterogeneous and protean manifestations. Early recognition and initiation of appropriate antifungal therapy might have a favourable outcome in such cases. Here we report three cases of Cryptococcosis among cancer patients in a tertiary care cancer centre in South India. All three patients were males of different ages at presentation with immunosuppression in the form of solid organ or hematologic malignancy and were using immunosuppressive medications like steroids or chemotherapeutic agents. They presented with cryptococcemia and cryptococcal meningitis. Patients with microbiologically proven cryptococcosis had poor outcome in this subgroup of patients.
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Affiliation(s)
| | - Swapna Raveendranath
- Department of Microbiology, Regional Cancer Centre, Thiruvananthapuram, Kerala, India
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12
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Munzen ME, Goncalves Garcia AD, Martinez LR. An update on the global treatment of invasive fungal infections. Future Microbiol 2023; 18:1095-1117. [PMID: 37750748 DOI: 10.2217/fmb-2022-0269] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023] Open
Abstract
Fungal infections are a serious problem affecting many people worldwide, creating critical economic and medical consequences. Fungi are ubiquitous and can cause invasive diseases in individuals mostly living in developing countries or with weakened immune systems, and antifungal drugs currently available have important limitations in tolerability and efficacy. In an effort to counteract the high morbidity and mortality rates associated with invasive fungal infections, various approaches are being utilized to discover and develop new antifungal agents. This review discusses the challenges posed by fungal infections, outlines different methods for developing antifungal drugs and reports on the status of drugs currently in clinical trials, which offer hope for combating this serious global problem.
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Affiliation(s)
- Melissa E Munzen
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, FL 32610, USA
| | | | - Luis R Martinez
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, FL 32610, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA
- Center for Immunology and Transplantation, University of Florida, Gainesville, FL 32610, USA
- Center for Translational Research in Neurodegenerative Disease, University of Florida, Gainesville, FL 32610, USA
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13
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Caza M, Santos DA, Burden E, Brisland A, Hu G, Kronstad JW. Proteasome inhibition as a therapeutic target for the fungal pathogen Cryptococcus neoformans. Microbiol Spectr 2023; 11:e0190423. [PMID: 37750732 PMCID: PMC10580939 DOI: 10.1128/spectrum.01904-23] [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: 05/05/2023] [Accepted: 08/07/2023] [Indexed: 09/27/2023] Open
Abstract
The current therapeutic challenges for treating fungal diseases demand new approaches and new drugs. A promising strategy involves combination therapy with agents of distinct mechanisms of action to increase fungicidal activity and limit the impact of mutations leading to resistance. In this study, we evaluated the antifungal potential of bortezomib by examining the inhibition of proteasome activity, cell proliferation, and capsule production by Cryptococcus neoformans, the causative agent of fungal meningoencephalitis. Chemical genetic screens with collections of deletion mutants identified potential druggable targets for combination therapy with bortezomib. In vitro assays of combinations of bortezomib with flucytosine, chlorpromazine, bafilomycin A1, copper sulfate, or hydroxyurea revealed antifungal effects against C. neoformans. Furthermore, combination treatment with bortezomib and flucytosine in a murine inhalation model of cryptococcosis resulted in the improvement of neurological functions and reduced fungal replication and dissemination, leading to a delay in disease progression. This study therefore highlights the utility of chemical genetic screens to identify new therapeutic approaches as well as the antifungal potential of proteasome inhibition. IMPORTANCE Fungal diseases of humans are difficult to treat, and there is a clear need for additional antifungal drugs, better diagnostics, effective vaccines, and new approaches to deal with emerging drug resistance. Fungi are challenging to control because they share many common biochemical functions with their mammalian hosts and it is therefore difficult to identify fungal-specific targets for drug development. One approach is to employ existing antifungal drugs in combination with agents that target common cellular processes at levels that are (ideally) not toxic for the host. We pursued this approach in this study by examining the potential of the clinically approved proteasome inhibitor bortezomib to influence the proliferation and virulence of Cryptococcus neoformans. We found that the combination of bortezomib with the anti-cryptococcal drug flucytosine improved the survival of infected mice, thus demonstrating the potential of this strategy for antifungal therapy.
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Affiliation(s)
- Mélissa Caza
- Department of Microbiology and Immunology, Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Daniel Assis Santos
- Department of Microbiology, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Elizabeth Burden
- Department of Microbiology and Immunology, Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Anna Brisland
- Department of Microbiology and Immunology, Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Guanggan Hu
- Department of Microbiology and Immunology, Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - James W. Kronstad
- Department of Microbiology and Immunology, Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
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14
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de Oliveira Kocerginsky P, Dos Santos Soares PH, Lyra HFS, Cadena PG, de Lima-Neto RG, Pontes-Filho NT, Lima-Filho JVM, Costa-Júnior SD, Neves RP, Cavalcanti IMF, Santos-Magalhães NS. Efficacy and non-toxicity of ciclopirox olamine-loaded liposomes against Cryptococcus neoformans clinical isolates. Braz J Microbiol 2023; 54:1513-1521. [PMID: 37540461 PMCID: PMC10484888 DOI: 10.1007/s42770-023-01071-6] [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: 04/14/2023] [Accepted: 07/03/2023] [Indexed: 08/05/2023] Open
Abstract
The aim of this study was to evaluate the efficacy and non-toxicity of ciclopirox olamine-loaded liposomes against Cryptococcus neoformans clinical isolates. Initially, 24-1 fractional experimental design was carried out to obtain an optimized formulation of liposomes containing CPO (CPO-LipoC), which were then used to prepare stealth liposomes (CPO-LipoS). Liposomal formulations were characterized by their mean size diameter, polydispersity index (PDI), and drug encapsulation efficiency (EE%). Immunosuppressed mice were exposed to CPO-LipoS at 0.5 mg/kg/day for 14 days to verify possible histopathological alterations in the liver and kidneys. Immunosuppressed mice infected with C. neoformans were treated with CPO-LipoS at 0.5 mg/kg/day for 14 days to quantify the fungal burden in spleen, liver, lungs, and brain. CPO-LipoS presented a mean size diameter, PDI, and EE% of 101.4 ± 0.7 nm, 0.307, and 96.4 ± 0.9%, respectively. CPO-LipoS was non-toxic for the liver and kidneys of immunosuppressed mice. At the survival curve, all infected animals submitted to treatment with CPO-LipoS survived until the end of the experiment. Treatment with CPO-LipoS reduced C. neoformans cells in the spleen (59.3 ± 3.4%), liver (75.0 ± 3.6%), lungs (75.7 ± 6.7%), and brain (54.2 ± 3.2%). CPO-LipoS exhibit antifungal activity against C. neoformans, and the encapsulation of CPO into stealth liposomes allows its use as a systemic drug for treating cryptococcosis.
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Affiliation(s)
- Patrícia de Oliveira Kocerginsky
- Biosciences Center, Laboratory of Medical Mycology, Federal University of Pernambuco (UFPE), Av Reitor Joaquim Amazonas, S/N, Cidade Universitária, Recife, PE, 50740-570, Brazil
- Keizo Asami Institute (iLIKA), Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235, Cidade Universitária, Recife, PE, 50670-901, Brazil
| | - Pedro Henrique Dos Santos Soares
- Keizo Asami Institute (iLIKA), Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235, Cidade Universitária, Recife, PE, 50670-901, Brazil
| | - Hannah Ferreira Soares Lyra
- Keizo Asami Institute (iLIKA), Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235, Cidade Universitária, Recife, PE, 50670-901, Brazil
| | - Pabyton Gonçalves Cadena
- Keizo Asami Institute (iLIKA), Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235, Cidade Universitária, Recife, PE, 50670-901, Brazil
- Department of Animal Morphology and Physiology, Federal Rural University of Pernambuco (UFRPE), Rua Dom Manoel de Medeiros, S/N, Dois Irmãos, Recife, PE, 52171-900, Brazil
| | - Reginaldo Gonçalves de Lima-Neto
- Biosciences Center, Laboratory of Medical Mycology, Federal University of Pernambuco (UFPE), Av Reitor Joaquim Amazonas, S/N, Cidade Universitária, Recife, PE, 50740-570, Brazil
- Health Sciences Center, Department of Tropical Medicine, Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235, Cidade Universitária, Recife, PE, 50670-901, Brazil
| | - Nicodemos Teles Pontes-Filho
- Center for Health Sciences, Department of Pathology, Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235, Cidade Universitária, Recife, PE, 50670-901, Brazil
| | - José Vitor Moreira Lima-Filho
- Department of Biology, Federal Rural University of Pernambuco (UFRPE), Rua Dom Manoel de Medeiros, 401, Dois Irmãos, Recife, PE, 52171-900, Brazil
| | - Sérgio Dias Costa-Júnior
- Keizo Asami Institute (iLIKA), Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235, Cidade Universitária, Recife, PE, 50670-901, Brazil
| | - Rejane Pereira Neves
- Biosciences Center, Laboratory of Medical Mycology, Federal University of Pernambuco (UFPE), Av Reitor Joaquim Amazonas, S/N, Cidade Universitária, Recife, PE, 50740-570, Brazil
| | - Isabella Macário Ferro Cavalcanti
- Keizo Asami Institute (iLIKA), Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235, Cidade Universitária, Recife, PE, 50670-901, Brazil.
- Academic Center of Vitória (CAV), Laboratory of Microbiology and Immunology, Vitória de Santo Antão, Federal University of Pernambuco (UFPE), Rua Alto Do Reservatório, S/N, Vitória de Santo Antão, PE, Brazil.
| | - Nereide Stela Santos-Magalhães
- Keizo Asami Institute (iLIKA), Federal University of Pernambuco (UFPE), Av. Prof. Moraes Rego, 1235, Cidade Universitária, Recife, PE, 50670-901, Brazil.
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15
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Carvajal SK, Melendres J, Escandón P, Firacative C. Reduced Susceptibility to Azoles in Cryptococcus gattii Correlates with the Substitution R258L in a Substrate Recognition Site of the Lanosterol 14-α-Demethylase. Microbiol Spectr 2023; 11:e0140323. [PMID: 37341584 PMCID: PMC10434158 DOI: 10.1128/spectrum.01403-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/01/2023] [Indexed: 06/22/2023] Open
Abstract
Cryptococcus neoformans and Cryptococcus gattii cause cryptococcosis, a life-threatening fungal infection affecting mostly immunocompromised patients. In fact, cryptococcal meningitis accounts for about 19% of AIDS-related deaths in the world. Because of long-term azole therapies to treat this mycosis, resistance to fluconazole leading to treatment failure and poor prognosis has long been reported for both fungal species. Among the mechanisms implicated in resistance to azoles, mutations in the ERG11 gene, encoding the azole target enzyme lanosterol 14-α-demethylase, have been described. This study aimed to establish the amino acid composition of ERG11 of Colombian clinical isolates of C. neoformans and C. gattii and to correlate any possible substitution with the in vitro susceptibility profile of the isolates to fluconazole, voriconazole, and itraconazole. Antifungal susceptibility testing results showed that C. gattii isolates are less susceptible to azoles than C. neoformans isolates, which could correlate with differences in the amino acid composition and structure of ERG11 of each species. In addition, in a C. gattii isolate with high MICs for fluconazole (64 μg/mL) and voriconazole (1 μg/mL), a G973T mutation resulting in the substitution R258L, located in substrate recognition site 3 of ERG11, was identified. This finding suggests the association of the newly reported substitution with the azole resistance phenotype in C. gattii. Further investigations are needed to determine the exact role that R258L plays in the decreased susceptibility to fluconazole and voriconazole, as well as to determine the participation of additional mechanisms of resistance to azole drugs. IMPORTANCE The fungal species Cryptococcus neoformans and C. gattii are human pathogens for which drug resistance or other treatment and management challenges exist. Here, we report differential susceptibility to azoles among both species, with some isolates displaying resistant phenotypes. Azoles are among the most commonly used drugs to treat cryptococcal infections. Our findings underscore the necessity of testing antifungal susceptibility in the clinical setting in order to assist patient management and beneficial outcomes. In addition, we report an amino acid change in the sequence of the target protein of azoles, which suggests that this change might be implicated in resistance to these drugs. Identifying and understanding possible mechanisms that affect drug affinity will eventually aid the design of new drugs that overcome the global growing concern of antifungal resistance.
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Affiliation(s)
| | - Javier Melendres
- Studies in Translational Microbiology and Emerging Diseases (MICROS) Research Group, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Patricia Escandón
- Group of Microbiology, Instituto Nacional de Salud, Bogotá, Colombia
| | - Carolina Firacative
- Studies in Translational Microbiology and Emerging Diseases (MICROS) Research Group, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia
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16
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Sousa NSOD, Almeida JDRD, Frickmann H, Lacerda MVG, Souza JVBD. Searching for new antifungals for the treatment of cryptococcosis. Rev Soc Bras Med Trop 2023; 56:e01212023. [PMID: 37493736 PMCID: PMC10367226 DOI: 10.1590/0037-8682-0121-2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 05/19/2023] [Indexed: 07/27/2023] Open
Abstract
There is a consensus that the antifungal repertoire for the treatment of cryptococcal infections is limited. Standard treatment involves the administration of an antifungal drug derived from natural sources (i.e., amphotericin B) and two other drugs developed synthetically (i.e., flucytosine and fluconazole). Despite treatment, the mortality rates associated with fungal cryptococcosis are high. Amphotericin B and flucytosine are toxic, require intravenous administration, and are usually unavailable in low-income countries because of their high cost. However, fluconazole is cost-effective, widely available, and harmless with regard to its side effects. However, fluconazole is a fungistatic agent that has contributed considerably to the increase in fungal resistance and frequent relapses in patients with cryptococcal meningitis. Therefore, there is an unquestionable need to identify new alternatives or adjuvants to conventional drugs for the treatment of cryptococcosis. A potential antifungal agent should be able to kill cryptococci and "bypass" the virulence mechanism of the yeast. Furthermore, it should have fungicidal action, low toxicity, high selectivity, easily penetrate the central nervous system, and widely available. In this review, we describe cryptococcosis, its conventional therapy, and failures arising from the use of drugs traditionally considered to be the reference standard. Additionally, we present the approaches used for the discovery of new drugs to counteract cryptococcosis, ranging from the conventional screening of natural products to the inclusion of structural modifications to optimize anticryptococcal activity, as well as drug repositioning and combined therapies.
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Affiliation(s)
| | | | - Hagen Frickmann
- Institute for Medical Microbiology, Virology and Hygiene, University Medicine Rostock, Germany
- Department of Microbiology and Hospital Hygiene, Bundeswehr Hospital Hamburg, Germany
| | - Marcus Vinícius Guimarães Lacerda
- Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brasil
- Instituto de Pesquisas Leônidas & Maria Deane, Fiocruz, Manaus, AM, Brasil
- University of Texas Medical Branch, Galveston, USA
| | - João Vicente Braga de Souza
- Programa de Pós-Graduação em Biodiversidade e Biotecnologia da Rede BIONORTE, Manaus, AM, Brasil
- Instituto Nacional de Pesquisas da Amazônia, Manaus, AM, Brasil
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17
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Ma Z, Wang X, Li C. Advances in anti-invasive fungal drug delivery systems. Zhejiang Da Xue Xue Bao Yi Xue Ban 2023; 52:318-327. [PMID: 37476943 PMCID: PMC10409907 DOI: 10.3724/zdxbyxb-2023-0030] [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: 01/20/2023] [Accepted: 05/31/2023] [Indexed: 07/22/2023]
Abstract
Currently, the first-line drugs for invasive fungal infections (IFI), such as amphotericin B, fluconazole and itraconazole, have drawbacks including poor water solubility, low bioavailability, and severe side effects. Using drug delivery systems is a promising strategy to improve the efficacy and safety of traditional antifungal therapy. Synthetic and biomimetic carriers have greatly facilitated the development of targeted delivery systems for antifungal drugs. Synthetic carrier drug delivery systems, such as liposomes, nanoparticles, polymer micelles, and microspheres, can improve the physicochemical properties of antifungal drugs, prolong their circulation time, enhance targeting capabilities, and reduce toxic side effects. Cell membrane biomimetic drug delivery systems, such as macrophage or red blood cell membrane-coated drug delivery systems, retain the membrane structure of somatic cells and confer various biological functions and specific targeting abilities to the loaded antifungal drugs, exhibiting better biocompatibility and lower toxicity. This article reviews the development of antifungal drug delivery systems and their application in the treatment of IFI, and also discusses the prospects of novel biomimetic carriers in antifungal drug delivery.
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Affiliation(s)
- Zhongyi Ma
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China.
| | - Xinyu Wang
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
| | - Chong Li
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China.
- Medical Research Institute, Southwest University, Chongqing 400715, China.
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18
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Acharya S, Allam RR, Karanjkar VK, Rathod D, Mahajan R, Deshpande P, Palkar A, Todmal S, Koli S, Dhande S, Dale J, Yeldandi VV, Harshana A, Agarwal R, Upadhyaya S, Nyendak M. Implementation of point-of-care testing and prevalence of cryptococcal antigenaemia among patients with advanced HIV disease in Mumbai, India. BMJ Open 2023; 13:e070500. [PMID: 37349096 PMCID: PMC10314426 DOI: 10.1136/bmjopen-2022-070500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Accepted: 06/08/2023] [Indexed: 06/24/2023] Open
Abstract
OBJECTIVES To describe the implementation of screening for cryptococcal antigenaemia by point-of-care (POC) serum cryptococcal antigen (CrAg) lateral flow assay, measure the prevalence and factors associated with serum cryptococcal antigenaemia in the routine programmatic setting. DESIGN Cross-sectional study. SETTING Seventeen publicly funded antiretroviral therapy (ART) centres in Mumbai, India. PARTICIPANTS Serum CrAg screening was offered to all adolescents (>10 years of age) and adults with advanced HIV disease (AHD) (CD4 <200 cells/mm3 or with WHO clinical stage III/IV) regardless of symptoms of cryptococcal meningitis. PRIMARY AND SECONDARY OUTCOME MEASURES The primary outcome was to describe the implementation of serum CrAg screening and secondary outcome was to measure the prevalence of serum cryptococcal antigenaemia and its risk factors. RESULTS A total of 2715 patients with AHD were tested for serum CrAg by POC assay. Of these, 25 (0.9%) had a CrAg positive result. Among CrAg-positive patients, only one had symptoms. Serum CrAg positivity was 3.6% (6/169) and 1.6% (6/520) among those presenting with CD4 <100 cells/mm3 in the treatment naïve and treatment experienced group, respectively. On multivariable analysis, CD4 count <100 cells/mm3 (OR: 2.3, 95% CI 1.01 to 5.3; p=0.05) and people living with HIV who were treatment naïve (OR: 2.5, 95% CI 1.04 to 6.0; p=0.04) were significantly associated with a positive serum CrAg result. Lumbar puncture was obtained in 20/25 patients within 4 days (range: 1-4 days) of positive serum CrAg result and one person was confirmed to have meningitis. All serum CrAg-positive patients who had a negative cerebrospinal fluid CrAg were offered pre-emptive therapy. CONCLUSIONS Implementation of a POC CrAg assay was possible with existing ART centre staff. Initiation of pre-emptive therapy and management of cryptococcal antigenaemia are operationally feasible at ART centres. The Indian National AIDS Control Programme may consider reflexive CrAg screening of all AHD patients with CD4 <100 cells/mm3.
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Affiliation(s)
| | - Ramesh Reddy Allam
- Division of Global HIV and Tuberculosis, Centers for Disease Control and Prevention, Delhi, India
| | | | | | - Raman Mahajan
- International Training and Education HIV (I-TECH), Delhi, India
| | | | - Amol Palkar
- International Training and Education HIV (I-TECH), Delhi, India
| | | | - Sagar Koli
- International Training and Education HIV (I-TECH), Delhi, India
| | - Sachin Dhande
- International Training and Education HIV (I-TECH), Delhi, India
| | | | | | - Amit Harshana
- International Training and Education HIV (I-TECH), Delhi, India
| | - Reshu Agarwal
- Division of Global HIV and Tuberculosis, Centers for Disease Control and Prevention, Delhi, India
| | - Sunita Upadhyaya
- Division of Global HIV and Tuberculosis, Centers for Disease Control and Prevention, Delhi, India
| | - Melissa Nyendak
- Division of Global HIV and Tuberculosis, Centers for Disease Control and Prevention, Delhi, India
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19
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Carmo A, Rocha M, Pereirinha P, Tomé R, Costa E. Antifungals: From Pharmacokinetics to Clinical Practice. Antibiotics (Basel) 2023; 12:antibiotics12050884. [PMID: 37237787 DOI: 10.3390/antibiotics12050884] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/30/2023] [Accepted: 05/05/2023] [Indexed: 05/28/2023] Open
Abstract
The use of antifungal drugs started in the 1950s with polyenes nystatin, natamycin and amphotericin B-deoxycholate (AmB). Until the present day, AmB has been considered to be a hallmark in the treatment of invasive systemic fungal infections. Nevertheless, the success and the use of AmB were associated with severe adverse effects which stimulated the development of new antifungal drugs such as azoles, pyrimidine antimetabolite, mitotic inhibitors, allylamines and echinochandins. However, all of these drugs presented one or more limitations associated with adverse reactions, administration route and more recently the development of resistance. To worsen this scenario, there has been an increase in fungal infections, especially in invasive systemic fungal infections that are particularly difficult to diagnose and treat. In 2022, the World Health Organization (WHO) published the first fungal priority pathogens list, alerting people to the increased incidence of invasive systemic fungal infections and to the associated risk of mortality/morbidity. The report also emphasized the need to rationally use existing drugs and develop new drugs. In this review, we performed an overview of the history of antifungals and their classification, mechanism of action, pharmacokinetic/pharmacodynamic (PK/PD) characteristics and clinical applications. In parallel, we also addressed the contribution of fungi biology and genetics to the development of resistance to antifungal drugs. Considering that drug effectiveness also depends on the mammalian host, we provide an overview on the roles of therapeutic drug monitoring and pharmacogenomics as means to improve the outcome, prevent/reduce antifungal toxicity and prevent the emergence of antifungal resistance. Finally, we present the new antifungals and their main characteristics.
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Affiliation(s)
- Anália Carmo
- Advanced Unit for Pharmacokinetics and Personalized Therapeutics, Clinical Pathology Department, Centro Hospitalar e Universitário de Coimbra, 3004-561 Coimbra, Portugal
| | - Marilia Rocha
- Advanced Unit for Pharmacokinetics and Personalized Therapeutics, Pharmacy Department, Centro Hospitalar e Universitário de Coimbra, 3004-561 Coimbra, Portugal
| | - Patricia Pereirinha
- Advanced Unit for Pharmacokinetics and Personalized Therapeutics, Pharmacy Department, Centro Hospitalar e Universitário de Coimbra, 3004-561 Coimbra, Portugal
| | - Rui Tomé
- Clinical Pathology Department, Centro Hospitalar e Universitário de Coimbra, 3004-561 Coimbra, Portugal
| | - Eulália Costa
- Advanced Unit for Pharmacokinetics and Personalized Therapeutics, Clinical Pathology Department, Centro Hospitalar e Universitário de Coimbra, 3004-561 Coimbra, Portugal
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20
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Li-Zhulanov NS, Zaikova NP, Sari S, Gülmez D, Sabuncuoğlu S, Ozadali-Sari K, Arikan-Akdagli S, Nefedov AA, Rybalova TV, Volcho KP, Salakhutdinov NF. Rational Design of New Monoterpene-Containing Azoles and Their Antifungal Activity. Antibiotics (Basel) 2023; 12:antibiotics12050818. [PMID: 37237723 DOI: 10.3390/antibiotics12050818] [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: 04/10/2023] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/28/2023] Open
Abstract
Azole antifungals, including fluconazole, have long been the first-line antifungal agents in the fight against fungal infections. The emergence of drug-resistant strains and the associated increase in mortality from systemic mycoses has prompted the development of new agents based on azoles. We reported a synthesis of novel monoterpene-containing azoles with high antifungal activity and low cytotoxicity. These hybrids demonstrated broad-spectrum activity against all tested fungal strains, with excellent minimum inhibitory concentration (MIC) values against both fluconazole-susceptible and fluconazole-resistant strains of Candida spp. Compounds 10a and 10c with cuminyl and pinenyl fragments demonstrated up to 100 times lower MICs than fluconazole against clinical isolates. The results indicated that the monoterpene-containing azoles had much lower MICs against fluconazole-resistant clinical isolates of Candida parapsilosis than their phenyl-containing counterpart. In addition, the compounds did not exhibit cytotoxicity at active concentrations in the MTT assay, indicating potential for further development as antifungal agents.
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Affiliation(s)
- Nikolai S Li-Zhulanov
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev Ave., 9, 630090 Novosibirsk, Russia
| | - Nadezhda P Zaikova
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev Ave., 9, 630090 Novosibirsk, Russia
| | - Suat Sari
- Department of Pharmaceutical Chemistry, Hacettepe University Faculty of Pharmacy, Sihhiye, Ankara 06100, Turkey
| | - Dolunay Gülmez
- Department of Medical Microbiology, Hacettepe University Faculty of Medicine, Sihhiye, Ankara 06100, Turkey
| | - Suna Sabuncuoğlu
- Department of Pharmaceutical Toxicology, Hacettepe University Faculty of Pharmacy, Sihhiye, Ankara 06100, Turkey
| | - Keriman Ozadali-Sari
- Department of Pharmaceutical Chemistry, Hacettepe University Faculty of Pharmacy, Sihhiye, Ankara 06100, Turkey
| | - Sevtap Arikan-Akdagli
- Department of Medical Microbiology, Hacettepe University Faculty of Medicine, Sihhiye, Ankara 06100, Turkey
| | - Andrey A Nefedov
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev Ave., 9, 630090 Novosibirsk, Russia
| | - Tatyana V Rybalova
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev Ave., 9, 630090 Novosibirsk, Russia
| | - Konstantin P Volcho
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev Ave., 9, 630090 Novosibirsk, Russia
| | - Nariman F Salakhutdinov
- N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Lavrentiev Ave., 9, 630090 Novosibirsk, Russia
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21
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de Oliveira H, Bezerra BT, Rodrigues ML. Antifungal Development and the Urgency of Minimizing the Impact of Fungal Diseases on Public Health. ACS BIO & MED CHEM AU 2023; 3:137-146. [PMID: 37101810 PMCID: PMC10125384 DOI: 10.1021/acsbiomedchemau.2c00055] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/03/2022] [Accepted: 11/04/2022] [Indexed: 04/28/2023]
Abstract
Fungal infections are a major public health problem resulting from the lack of public policies addressing these diseases, toxic and/or expensive therapeutic tools, scarce diagnostic tests, and unavailable vaccines. In this Perspective, we discuss the need for novel antifungal alternatives, highlighting new initiatives based on drug repurposing and the development of novel antifungals.
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Affiliation(s)
| | - Bárbara T. Bezerra
- Instituto
Carlos Chagas, Fundação Oswaldo Cruz (Fiocruz), Curitiba81310-020, Brazil
| | - Marcio L. Rodrigues
- Instituto
Carlos Chagas, Fundação Oswaldo Cruz (Fiocruz), Curitiba81310-020, Brazil
- Instituto
de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro, Rio de Janeiro21941-902, Brazil
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22
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Deng H, Song J, Huang Y, Yang C, Zang X, Zhou Y, Li H, Dai B, Xue X. Combating increased antifungal drug resistance in Cryptococcus, what should we do in the future? Acta Biochim Biophys Sin (Shanghai) 2023; 55:540-547. [PMID: 36815374 DOI: 10.3724/abbs.2023011] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Few therapeutic drugs and increased drug resistance have aggravated the current treatment difficulties of Cryptococcus in recent years. To better understand the antifungal drug resistance mechanism and treatment strategy of cryptococcosis. In this review, by combining the fundamental features of Cryptococcus reproduction leading to changes in its genome, we review recent research into the mechanism of four current anti-cryptococcal agents, coupled with new therapeutic strategies and the application of advanced technologies WGS and CRISPR-Cas9 in this field, hoping to provide a broad idea for the future clinical therapy of cryptococcosis.
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Affiliation(s)
- Hengyu Deng
- Affiliated Hospital of Weifang Medical University, School of Clinical Medicine, Weifang Medical University, Weifang 261053, China
| | - Jialin Song
- Affiliated Hospital of Weifang Medical University, School of Clinical Medicine, Weifang Medical University, Weifang 261053, China
| | - Yemei Huang
- Department of Respiratory and Critical Care, Beijing Shijitan Hospital, Capital Medical University; Peking University Ninth School of Clinical Medicine, Beijing 100089, China
| | - Chen Yang
- Department of Laboratory Medicine, the First Medical Centre, Chinese PLA General Hospital, Beijing 100853, China
| | - Xuelei Zang
- Department of Respiratory and Critical Care, Beijing Shijitan Hospital, Capital Medical University; Peking University Ninth School of Clinical Medicine, Beijing 100089, China
| | - Yangyu Zhou
- Department of Respiratory and Critical Care, Beijing Shijitan Hospital, Capital Medical University; Peking University Ninth School of Clinical Medicine, Beijing 100089, China
| | - Hongli Li
- Affiliated Hospital of Weifang Medical University, School of Clinical Medicine, Weifang Medical University, Weifang 261053, China
| | - Bin Dai
- Department of Respiratory and Critical Care, Beijing Shijitan Hospital, Capital Medical University; Peking University Ninth School of Clinical Medicine, Beijing 100089, China
| | - Xinying Xue
- Affiliated Hospital of Weifang Medical University, School of Clinical Medicine, Weifang Medical University, Weifang 261053, China.,Department of Respiratory and Critical Care, Beijing Shijitan Hospital, Capital Medical University; Peking University Ninth School of Clinical Medicine, Beijing 100089, China
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Jezewski AJ, Ristow LC, Krysan DJ. Carbon Dioxide Potentiates Flucytosine Susceptibility in Cryptococcus neoformans. Microbiol Spectr 2023; 11:e0478322. [PMID: 36719209 PMCID: PMC10101005 DOI: 10.1128/spectrum.04783-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 01/11/2023] [Indexed: 02/01/2023] Open
Abstract
Cryptococcal meningoencephalitis remains a global health threat with limited treatment options. Currently, the most effective treatment regimens are based on a combination therapy of flucytosine with either amphotericin B or fluconazole. Slow but steady progress is being made toward universal access to flucytosine-based therapies. The broadening access to flucytosine combination therapies will be accompanied by the need for microbiological methods that reliably determine strain susceptibility. This is especially true considering that flucytosine susceptibility can vary widely across clinical isolates. Identifying culture conditions that best represent the host environment are likely optimal and may even be required for accurately determining in vivo flucytosine susceptibility. Here, we report that culture conditions incorporating host-like concentrations of carbon dioxide (CO2) potentiated flucytosine susceptibilities across clinical isolates (10 of 11) that exhibited a range of MIC values under ambient growth conditions (2 to 8 μg/mL) by standard Clinical and Laboratory Standards Institute susceptibility testing. CO2 induced a dose-dependent increase in flucytosine susceptibility between 2- and 8-fold over standard conditions. The CO2-dependent increase in flucytosine susceptibility did not correspond to an increase in fluorouracil susceptibility, indicating a central role for flucytosine uptake through the cytosine permease in the presence of host-like CO2 concentrations. Indeed, the expression of the cytosine permease gene (FCY2) was induced 18- to 60-fold in the mouse lung environment. Therefore, the activity of flucytosine is likely to be very dependent upon host environment and may not be well represented by standard in vitro susceptibility testing. IMPORTANCE Cryptococcus neoformans causes life-threatening infections of the brain. The most effective treatment regimens are based on flucytosine-based combination therapy, which has led to increasingly successful broadening of access to flucytosine globally. Wider use of flucytosine-based therapies for cryptococcal infections will require the ability to reliably determine clinical isolate susceptibilities. We showed that host-like carbon dioxide stress affected flucytosine susceptibility, and this likely occurred through flucytosine uptake. We further showed that the gene encoding the permease, FCY2, and that is responsible for flucytosine uptake was strongly induced during cryptococcal infection. Our data provide insights into the distinctions between the activity of flucytosine in the host environment and during in vitro susceptibility testing.
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Affiliation(s)
- Andrew J. Jezewski
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Laura C. Ristow
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Damian J. Krysan
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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Sigera LSM, Denning DW. Flucytosine and its clinical usage. Ther Adv Infect Dis 2023; 10:20499361231161387. [PMID: 37051439 PMCID: PMC10084540 DOI: 10.1177/20499361231161387] [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: 01/02/2023] [Accepted: 02/13/2023] [Indexed: 04/14/2023] Open
Abstract
Flucytosine is an antifungal agent first licensed in the 1970's. However, its clinical value has long been overlooked and its availability across the globe is limited. This review highlights the important clinical and pharmacological aspects of flucytosine. This a narrative review of the clinical and in vitro susceptibility literature, with a focus on clinical uses for flucytosine. Detailed literature review including early literature related to primary and acquired resistance to flucytosine. Flucytosine has good antifungal activity against Cryptococcus species, Candida species, and dematiaceous fungi. Its water solubility enables good penetration into the eye, urinary tract, central nervous system (CNS), cardiac vegetations and fungal biofilms. In combination with amphotericin B, it shows early fungicidal activity against Cryptococcus species, and this translates to ~20% improved survival in cryptococcal meningitis. Combination therapy also reduces the mortality of Candida meningitis, and should be used in neonatal candidiasis because of the high frequency of CNS infection. Monotherapy for urinary candidiasis is under-studied, but is usually effective. It is probably valuable in the treatment of Candida endocarditis and endophthalmitis: there are few data. It is not effective for aspergillosis or mucormycosis. Flucytosine monotherapy of urinary candidiasis resulted in 22% developing resistance on therapy and failing therapy, and in 29% of 21 patients with cryptococcosis. Certain regions of the world still do not have access to flucytosine compromising the management of certain severe fungal infections. Flucytosine has an important role in combination therapy for yeast and dematiaceous infections and probably as monotherapy for urinary candidiasis, with a modest risk of resistance emergence. Facilitating access to flucytosine in those regions (especially low-income countries) might alleviate the mortality of invasive fungal diseases.
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Affiliation(s)
| | - David W. Denning
- Division of Infection, Immunity & Respiratory Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
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25
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Temfack E, Lortholary O. Access to flucytosine for the treatment of HIV-associated cryptococcal meningitis in Africa. THE LANCET. INFECTIOUS DISEASES 2022; 22:1262-1264. [PMID: 35750066 DOI: 10.1016/s1473-3099(22)00315-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Affiliation(s)
- Elvis Temfack
- Africa Centers for Disease Control and Prevention, Addis Ababa, Ethiopia; National Public Health Laboratory, Yaoundé, Cameroon.
| | - Olivier Lortholary
- Molecular Mycology Unit, Institut Pasteur of Paris, Paris, France; Department of Infectious and Tropical Diseases, University of Paris Cité, Paris, France; Department of Infectious and Tropical Diseases, Necker Hospital, Paris, France
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Priest SJ, Yadav V, Roth C, Dahlmann TA, Kück U, Magwene PM, Heitman J. Uncontrolled transposition following RNAi loss causes hypermutation and antifungal drug resistance in clinical isolates of Cryptococcus neoformans. Nat Microbiol 2022; 7:1239-1251. [PMID: 35918426 PMCID: PMC10840647 DOI: 10.1038/s41564-022-01183-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 06/23/2022] [Indexed: 02/07/2023]
Abstract
Cryptococcus neoformans infections cause approximately 15% of AIDS-related deaths owing to a combination of limited antifungal therapies and drug resistance. A collection of clinical and environmental C. neoformans isolates were assayed for increased mutation rates via fluctuation analysis, and we identified two hypermutator C. neoformans clinical isolates with increased mutation rates when exposed to the combination of rapamycin and FK506. Sequencing of drug target genes found that Cnl1 transposon insertions conferred the majority of resistance to rapamycin and FK506 and could also independently cause resistance to 5-fluoroorotic acid and the clinically relevant antifungal 5-flucytosine. Whole-genome sequencing revealed both hypermutator genomes harbour a nonsense mutation in the RNA-interference component ZNF3 and hundreds of Cnl1 elements organized into massive subtelomeric arrays on each of the fourteen chromosomes. Quantitative trait locus mapping in 28 progeny derived from a cross between a hypermutator and wild-type identified a locus associated with hypermutation that included znf3. CRISPR editing of the znf3 nonsense mutation abolished hypermutation and restored small-interfering-RNA production. We conclude that hypermutation and drug resistance in these clinical isolates result from RNA-interference loss and accumulation of Cnl1 elements.
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Affiliation(s)
- Shelby J Priest
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Vikas Yadav
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Cullen Roth
- Department of Biology, Duke University, Durham, NC, USA
- University Program in Genetics and Genomics, Duke University, Durham, NC, USA
| | - Tim A Dahlmann
- Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, Bochum, Germany
| | - Ulrich Kück
- Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, Bochum, Germany
| | | | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA.
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Larson B, Shroufi A, Muthoga C, Oladele R, Rajasingham R, Jordan A, Jarvis JN, Chiller TM, Govender NP. Induction-phase treatment costs for cryptococcal meningitis in high HIV-burden African countries: New opportunities with lower costs. Wellcome Open Res 2022; 6:140. [PMID: 35706922 PMCID: PMC9184925 DOI: 10.12688/wellcomeopenres.16776.3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2022] [Indexed: 11/20/2022] Open
Abstract
Introduction: Access to and the cost of induction treatment for cryptococcal meningitis (CM) is rapidly changing. The newly-announced price for flucytosine ($0.75 per 500 mg pill) and possibly lower prices for liposomal amphotericin B (AmB-L) create opportunities to reduce CM treatment costs compared to the current standard treatment in low- and middle-income countries. Methods: We developed an Excel-based cost model to estimate health system treatment costs for CM over a two-week induction phase for multiple treatment combinations, newly feasible with improved access to flucytosine and AmB-L. CM treatment costs include medications, laboratory tests and other hospital-based costs (bed-day costs and healthcare worker time). We report results from applying the model using country-specific information for South Africa, Uganda, Nigeria, and Botswana. Results: A 14-day induction-phase of seven days of inpatient AmB-D with flucytosine, followed by seven days of high-dose fluconazole as an outpatient, will cost health systems less than a 14-day hospital stay with AmB-D and fluconazole. If daily AmB-L replaces AmB-D for those with baseline renal dysfunction, with a cost of $50 or less per 50 mg vial, incremental costs would still be less than the AmB-D with fluconazole regimen. Simple oral combinations (e.g., seven days of flucytosine with fluconazole as an inpatient) are practical when AmB-D is not available, and treatment costs would remain less than the current standard treatment. Conclusions: Improved access to and lower prices for flucytosine and AmB-L create opportunities for improving CM treatment regimens. An induction regimen of flucytosine and AmB-D for seven days is less costly than standard care in the settings studied here. As this regimen has also been shown to be more effective than current standard care, countries should prioritize scaling up flucytosine access. The cost of AmB-L based regimens is highly dependent on the price of AmB-L, which currently remains unclear.
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Affiliation(s)
- Bruce Larson
- Global Health, Boston University School of Public Health, Boston, MA, 02118, USA
- Health Economics and Epidemiology Research Office, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Charles Muthoga
- Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana
| | - Rita Oladele
- College of Medicine, Univerity of Lagos, Lagos, Nigeria
| | - Radha Rajasingham
- Division of Infectious Diseases & International Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Alexander Jordan
- Mycotic Diseases Branch, Centers for Disease Controls and Prevention, Atlanta, Georgia, USA
| | - Joseph N. Jarvis
- Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Tom M. Chiller
- Mycotic Diseases Branch, Centers for Disease Controls and Prevention, Atlanta, Georgia, USA
| | - Nelesh P. Govender
- National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
- University of Witwatersrand, Johannesburg, South Africa
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Larson B, Shroufi A, Muthoga C, Oladele R, Rajasingham R, Jordan A, Jarvis JN, Chiller TM, Govender NP. Induction-phase treatment costs for cryptococcal meningitis in high HIV-burden African countries: New opportunities with lower costs. Wellcome Open Res 2022; 6:140. [PMID: 35706922 PMCID: PMC9184925 DOI: 10.12688/wellcomeopenres.16776.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/24/2022] [Indexed: 11/20/2022] Open
Abstract
Introduction: Access to and the cost of induction treatment for cryptococcal meningitis (CM) is rapidly changing. The newly-announced price for flucytosine ($0.75 per 500 mg pill) and possibly lower prices for liposomal amphotericin B (AmB-L) create opportunities to reduce CM treatment costs compared to the current standard treatment in low- and middle-income countries. Methods: We developed an Excel-based cost model to estimate health system treatment costs for CM over a two-week induction phase for multiple treatment combinations, newly feasible with improved access to flucytosine and AmB-L. CM treatment costs include medications, laboratory tests and other hospital-based costs (bed-day costs and healthcare worker time). We report results from applying the model using country-specific information for South Africa, Uganda, Nigeria, and Botswana. Results: A 14-day induction-phase of seven days of inpatient AmB-D with flucytosine, followed by seven days of high-dose fluconazole as an outpatient, will cost health systems less than a 14-day hospital stay with AmB-D and fluconazole. If daily AmB-L replaces AmB-D for those with baseline renal dysfunction, with a cost of $50 or less per 50 mg vial, incremental costs would still be less than the AmB-D with fluconazole regimen. Simple oral combinations (e.g., seven days of flucytosine with fluconazole as an inpatient) are practical when AmB-D is not available, and treatment costs would remain less than the current standard treatment. Conclusions: Improved access to, and lower prices for flucytosine and AmB-L create opportunities for improving CM treatment regimens. An induction regimen of flucytosine and AmB-D for seven days is less costly than standard care in the settings studied here. As this regimen has also been shown to be more effective than current standard care, countries should prioritize scaling up flucytosine access. The cost of AmB-L based regimens is highly dependent on the price of AmB-L, which currently remains unclear.
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Affiliation(s)
- Bruce Larson
- Global Health, Boston University School of Public Health, Boston, MA, 02118, USA
- Health Economics and Epidemiology Research Office, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Charles Muthoga
- Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana
| | - Rita Oladele
- College of Medicine, Univerity of Lagos, Lagos, Nigeria
| | - Radha Rajasingham
- Division of Infectious Diseases & International Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Alexander Jordan
- Mycotic Diseases Branch, Centers for Disease Controls and Prevention, Atlanta, Georgia, USA
| | - Joseph N. Jarvis
- Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Tom M. Chiller
- Mycotic Diseases Branch, Centers for Disease Controls and Prevention, Atlanta, Georgia, USA
| | - Nelesh P. Govender
- National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
- University of Witwatersrand, Johannesburg, South Africa
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29
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Chen X, Tan Q, Lyu Q, Yu C, Jiang N, Li J, Luo L. Unmarked Gene Editing in Clavibacter michiganensis Using CRISPR/Cas9 and 5-Fluorocytosine Counterselection. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2022; 35:4-14. [PMID: 34543054 DOI: 10.1094/mpmi-07-21-0179-ta] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Plant-pathogenic bacteria in the genus Clavibacter are important quarantine species that cause considerable economic loss worldwide. The development of effective gene editing techniques and additional selectable markers is essential to expedite gene functional analysis in this important Gram-positive genus. The current study details a highly efficient unmarked CRISPR/Cas9-mediated gene editing system in Clavibacter michiganensis, which couples the expression of cas9 and single-guide RNA with homology-directed repair templates and the negative selectable marker codA::upp within a single plasmid. Initial experiments indicated that CRISPR/Cas9-mediated transformation could be utilized for both site-directed mutagenesis, in which an A to G point mutation was introduced at the 128th nucleotide of the C. michiganensis rpsL gene to generate a streptomycin-resistant mutant, and complete gene knockout, in which the deletion of the C. michiganensis celA or katA genes resulted in transformants that lacked cellulase and catalase activity, respectively. In subsequent experiments, the introduction of the codA::upp cassette into the transformation vector facilitated the counterselection of unmarked transformants by incubation in the absence of the selective antibiotic, followed by plating on M9 agar containing 5-fluorocytosine at 100 μg/ml, in which an unmarked katA mutant lacking the transformation vector was recovered. Compared with conventional homologous recombination, the unmarked CRISPR/Cas9-mediated system was more useful and convenient because it allowed the template plasmid to be reused repeatedly to facilitate the editing of multiple genes, which constitutes a major advancement that could revolutionize research into C. michiganensis and other Clavibacter spp.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Xing Chen
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, Beijing Key Laboratory of Seed Disease Testing and Control, China Agricultural University; Beijing, P. R. China
| | - Qing Tan
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, Beijing Key Laboratory of Seed Disease Testing and Control, China Agricultural University; Beijing, P. R. China
| | - Qingyang Lyu
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, Beijing Key Laboratory of Seed Disease Testing and Control, China Agricultural University; Beijing, P. R. China
- CAS Key Laboratory of Environmental and Applied Microbiology, Environmental Microbiology Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, P. R. China
| | - Chengxuan Yu
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, Beijing Key Laboratory of Seed Disease Testing and Control, China Agricultural University; Beijing, P. R. China
| | - Na Jiang
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, Beijing Key Laboratory of Seed Disease Testing and Control, China Agricultural University; Beijing, P. R. China
| | - Jianqiang Li
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, Beijing Key Laboratory of Seed Disease Testing and Control, China Agricultural University; Beijing, P. R. China
| | - Laixin Luo
- Department of Plant Pathology and MOA Key Laboratory of Pest Monitoring and Green Management, College of Plant Protection, Beijing Key Laboratory of Seed Disease Testing and Control, China Agricultural University; Beijing, P. R. China
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31
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[AmBisome, three challenges: Candida auris infection, central nervous system infection, and biofilm-associated infection]. Rev Iberoam Micol 2021; 38:84-90. [PMID: 34144836 DOI: 10.1016/j.riam.2021.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/21/2021] [Accepted: 03/31/2021] [Indexed: 12/17/2022] Open
Abstract
The treatment of invasive fungal infections remains a challenge, both for the diagnosis and for the need of providing the appropriate antifungal therapy. Candida auris is a pathogenic yeast that is responsible for hospital outbreaks, especially in intensive care units; it is characterized by a high resistance to the antifungal agents and can become multidrug-resistant. At present, the recommended antifungal agents for the invasive infections with this pathogen are echinocandins, always after carrying out an antifungal susceptibility testing. In case of no clinical response or persistent candidemia, the addition of liposomal amphotericin B or isavuconazole may be considered. Both fungal infection of the central nervous system and that associated with biomedical devices remain rare entities affecting mainly immunocompromised patients. However, an increase in their incidence in recent years, along with high morbidity and mortality, has been shown. The treatment of these infections is conditioned by the limited knowledge of the pharmacokinetic properties of antifungals. A better understanding of the pharmacokinetic and pharmacodynamic parameters of the different antifungals is essential to determine the efficacy of the antifungal agents in the treatment of these infections.
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32
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Larson B, Shroufi A, Muthoga C, Oladele R, Rajasingham R, Jordan A, Jarvis JN, Chiller TM, Govender NP. Induction-phase treatment costs for cryptococcal meningitis in high HIV-burden African countries: New opportunities with lower costs. Wellcome Open Res 2021; 6:140. [PMID: 35706922 PMCID: PMC9184925 DOI: 10.12688/wellcomeopenres.16776.1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/25/2021] [Indexed: 11/20/2022] Open
Abstract
Introduction: Access to and the cost of induction treatment for cryptococcal meningitis (CM) is rapidly changing. The newly-announced price for flucytosine ($0.75 per 500 mg pill) and possibly lower prices for liposomal amphotericin B (AmB-L) create opportunities to reduce CM treatment costs compared to the current standard treatment in low- and middle-income countries. Methods: We developed an Excel-based cost model to estimate health system treatment costs for CM over a two-week induction phase for multiple treatment combinations, newly feasible with improved access to flucytosine and AmB-L. CM treatment costs include medications, laboratory tests and other hospital-based costs (bed-day costs and healthcare worker time). We report results from applying the model using country-specific information for South Africa, Uganda, Nigeria, and Botswana. Results: A 14-day induction-phase of seven days of inpatient AmB-D with flucytosine, followed by seven days of high-dose fluconazole as an outpatient, will cost health systems less than a 14-day hospital stay with AmB-D and fluconazole. If daily AmB-L replaces AmB-D for those with baseline renal dysfunction, with a cost of $50 or less per 50 mg vial, incremental costs would still be less than the AmB-D with fluconazole regimen. Simple oral combinations (e.g., seven days of flucytosine with fluconazole as an inpatient) are practical when AmB-D is not available, and treatment costs would remain less than the current standard treatment. Conclusions: Improved access to, and lower prices for flucytosine and AmB-L create opportunities for improving CM treatment regimens. An induction regimen of flucytosine and AmB-D for seven days is less costly than standard care in the settings studied here. As this regimen has also been shown to be more effective than current standard care, countries should prioritize scaling up flucytosine access. The cost of AmB-L based regimens is highly dependent on the price of AmB-L, which currently remains unclear.
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Affiliation(s)
- Bruce Larson
- Global Health, Boston University School of Public Health, Boston, MA, 02118, USA
- Health Economics and Epidemiology Research Office, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Charles Muthoga
- Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana
| | - Rita Oladele
- College of Medicine, Univerity of Lagos, Lagos, Nigeria
| | - Radha Rajasingham
- Division of Infectious Diseases & International Medicine, University of Minnesota, Minneapolis, Minnesota, USA
| | - Alexander Jordan
- Mycotic Diseases Branch, Centers for Disease Controls and Prevention, Atlanta, Georgia, USA
| | - Joseph N. Jarvis
- Botswana Harvard AIDS Institute Partnership, Gaborone, Botswana
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Tom M. Chiller
- Mycotic Diseases Branch, Centers for Disease Controls and Prevention, Atlanta, Georgia, USA
| | - Nelesh P. Govender
- National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa
- University of Witwatersrand, Johannesburg, South Africa
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Abstract
Pathogenic fungi have several mechanisms of resistance to antifungal drugs, driven by the genetic plasticity and versatility of their homeostatic responses to stressful environmental cues. We critically review the molecular mechanisms of resistance and cellular adaptations of pathogenic fungi in response to antifungals and discuss the factors contributing to such resistance. We offer suggestions for the translational and clinical research agenda of this rapidly evolving and medically important field. A better understanding of antifungal resistance should assist in developing better detection tools and inform optimal strategies for preventing and treating refractory mycoses in the future.
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Affiliation(s)
- Ronen Ben-Ami
- Infectious Diseases Department, Sackler School of Medicine, Tel Aviv University, Tel Aviv Sourasky Medical Center, 6 Weizmann, Tel Aviv 64239, Israel
| | - Dimitrios P Kontoyiannis
- Infectious Diseases, University of Texas M D Anderson Cancer Center, 1515 Holcombe, Houston, TX 77030, USA.
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Boulware DR, Nalintya E, Rajasingham R, Kirumira P, Naluyima R, Turya F, Namanda S, Rutakingirwa MK, Skipper CP, Nikweri Y, Hullsiek KH, Bangdiwala AS, Meya DB. Adjunctive sertraline for asymptomatic cryptococcal antigenemia: A randomized clinical trial. Med Mycol 2021; 58:1037-1043. [PMID: 32415846 DOI: 10.1093/mmy/myaa033] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 04/09/2020] [Accepted: 05/12/2020] [Indexed: 12/13/2022] Open
Abstract
Cryptococcal antigen (CrAg) screening in HIV-infected persons with CD4 < 100 cells/µl can reduce meningitis and death, yet preemptive fluconazole therapy fails in ∼25%. Sertraline has in vitro and in vivo activity against Cryptococcus and is synergistic with fluconazole in mice. We evaluated the efficacy and safety of sertraline in asymptomatic cryptococcal antigenemia. We conducted a randomized trial of asymptomatic CrAg-positive Ugandans from November 2017 to February 2018. All subjects received WHO standard therapy of fluconazole 800 mg for 2 weeks, then 400 mg for 10 weeks, then 200 mg through 24 weeks. Participants were randomized to receive adjunctive sertraline or placebo, given in once-weekly escalating 100 mg/day doses up to 400 mg/day, which was then given for 8 weeks, then tapered. The primary endpoint was meningitis-free 6-month survival. The data and safety monitoring board halted the trial after 21 subjects were enrolled due to safety concerns. Meningitis-free 6-month survival occurred in 9 of 11 of placebo participants and 10 of 10 of sertraline participants. However, seven serious adverse events (SAEs) occurred (n = 4 sertraline group; n = 3 placebo group). Three SAEs in the sertraline group presented with psychosis and aggressive behavioral changes with one meeting Hunter's criteria for serotonin syndrome while receiving 200 mg/day sertraline. Two transient psychoses were associated with antecedent fluconazole and sertraline interruption. The serotonin syndrome resolved within 1 day, but psychosis persisted for 4 months after sertraline discontinuation. Sertraline was associated with excess SAEs of psychosis. Due to early stopping, we were unable to determine any efficacy for cryptococcal antigenemia.
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Affiliation(s)
| | | | | | - Paul Kirumira
- Infectious Diseases Institute, Makerere University, Uganda
| | - Rose Naluyima
- Infectious Diseases Institute, Makerere University, Uganda
| | - Fred Turya
- Infectious Diseases Institute, Makerere University, Uganda
| | - Sylvia Namanda
- Infectious Diseases Institute, Makerere University, Uganda
| | | | - Caleb P Skipper
- University of Minnesota, Minneapolis, MN, USA.,Infectious Diseases Institute, Makerere University, Uganda
| | - Yofesi Nikweri
- Medical Research Council/Uganda Virus Research Institute & London School of Hygiene and Tropical Medicine (MRC/UVRI & LSHTM), Uganda Research Unit, Masaka Station
| | | | | | - David B Meya
- University of Minnesota, Minneapolis, MN, USA.,Infectious Diseases Institute, Makerere University, Uganda.,Department of Medicine, School of Medicine, College of Health Sciences, Makerere University, Kampala, Uganda
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35
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Kryštůfek R, Šácha P, Starková J, Brynda J, Hradilek M, Tloušt'ová E, Grzymska J, Rut W, Boucher MJ, Drąg M, Majer P, Hájek M, Řezáčová P, Madhani HD, Craik CS, Konvalinka J. Re-emerging Aspartic Protease Targets: Examining Cryptococcus neoformans Major Aspartyl Peptidase 1 as a Target for Antifungal Drug Discovery. J Med Chem 2021; 64:6706-6719. [PMID: 34006103 PMCID: PMC8165695 DOI: 10.1021/acs.jmedchem.0c02177] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Cryptococcosis is
an invasive infection that accounts for 15% of
AIDS-related fatalities. Still, treating cryptococcosis remains a
significant challenge due to the poor availability of effective antifungal
therapies and emergence of drug resistance. Interestingly, protease
inhibitor components of antiretroviral therapy regimens have shown
some clinical benefits in these opportunistic infections. We investigated
Major aspartyl peptidase 1 (May1), a secreted Cryptococcus
neoformans protease, as a possible target for the
development of drugs that act against both fungal and retroviral aspartyl
proteases. Here, we describe the biochemical characterization of May1,
present its high-resolution X-ray structure, and provide its substrate
specificity analysis. Through combinatorial screening of 11,520 compounds,
we identified a potent inhibitor of May1 and HIV protease. This dual-specificity
inhibitor exhibits antifungal activity in yeast culture, low cytotoxicity,
and low off-target activity against host proteases and could thus
serve as a lead compound for further development of May1 and HIV protease
inhibitors.
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Affiliation(s)
- Robin Kryštůfek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, Prague 6 16610, Czech Republic.,Department of Physical and Macromolecular Chemistry, Faculty of Science, Charles UniversityHlavova 8, Prague 2 12843, Czech Republic
| | - Pavel Šácha
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, Prague 6 16610, Czech Republic.,Department of Biochemistry, Faculty of Science, Charles UniversityHlavova 8, Prague 2 12843, Czech Republic
| | - Jana Starková
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, Prague 6 16610, Czech Republic
| | - Jiří Brynda
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, Prague 6 16610, Czech Republic.,Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, Prague 4 14220, Czech Republic
| | - Martin Hradilek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, Prague 6 16610, Czech Republic
| | - Eva Tloušt'ová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, Prague 6 16610, Czech Republic
| | - Justyna Grzymska
- Department of Chemical Biology and Bioimaging, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, Wroclaw 50-370, Poland
| | - Wioletta Rut
- Department of Chemical Biology and Bioimaging, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, Wroclaw 50-370, Poland
| | - Michael J Boucher
- Department of Biochemistry & Biophysics, University of California, San Francisco, UCSF Genentech Hall, 600 16th St Rm N374, San Francisco, California 94158, United States
| | - Marcin Drąg
- Department of Chemical Biology and Bioimaging, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, Wroclaw 50-370, Poland
| | - Pavel Majer
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, Prague 6 16610, Czech Republic
| | - Miroslav Hájek
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, Prague 6 16610, Czech Republic
| | - Pavlína Řezáčová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, Prague 6 16610, Czech Republic.,Institute of Molecular Genetics of the Czech Academy of Sciences, Vídeňská 1083, Prague 4 14220, Czech Republic
| | - Hiten D Madhani
- Department of Biochemistry & Biophysics, University of California, San Francisco, UCSF Genentech Hall, 600 16th St Rm N374, San Francisco, California 94158, United States.,Chan-Zuckerberg Biohub, 499 Illinois Street, San Francisco, California 94158, United States
| | - Charles S Craik
- Department of Pharmaceutical Chemistry, University of California San Francisco, UCSF Genentech Hall, 600 16th St Rm S512, San Francisco, California 94158, United States
| | - Jan Konvalinka
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo n. 2, Prague 6 16610, Czech Republic.,Department of Biochemistry, Faculty of Science, Charles UniversityHlavova 8, Prague 2 12843, Czech Republic
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36
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Chen CH, Li H, Chen HM, Chen YM, Chang YJ, Lin PY, Hsu CW, Tseng PT, Lin KH, Tu YK. Efficacy of induction regimens for cryptococcal meningitis in HIV-infected adults: a systematic review and network meta-analysis. Sci Rep 2021; 11:8565. [PMID: 33883566 PMCID: PMC8060388 DOI: 10.1038/s41598-021-87726-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 04/01/2021] [Indexed: 11/09/2022] Open
Abstract
Cryptococcal meningitis (CM) is the most fatal adult meningitis in patients with human immunodeficiency virus (HIV). There is no conclusive evidence for the superiority of 1-week amphotericin B deoxycholate (AmphB) + flucytosine (5-FC) regimen over other antifungals in the management of HIV patients with CM (HIV-CM patients). We aimed to evaluate the differences in efficacy and tolerability of different antifungal agents in HIV-CM patients by conducting a current network meta-analysis NMA. Overall, 19 randomized controlled trials were included with 2642 participants. A regimen indicated a possibly lower early mortality rate, namely, AmphB + 5-FC + Azole (OR = 1.1E-12, 95% CIs = 1.3E-41 to 0.06) comparing to AmphB + 5-FC. The current NMA provides evidence that AmphB + 5-FC + Azole are superior to all the investigated treatments for induction regimen in HIV-CM patients.
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Affiliation(s)
- Chang-Hua Chen
- Division of Infectious Diseases, Department of Internal Medicine, Changhua Christian Hospital, Changhua, Taiwan
- Center for Infection Prevention and Control, Changhua Christian Hospital, Changhua, 500, Taiwan
- National Chung Hsing University, Taichung, Taiwan
- Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung, Taiwan
| | - Hua Li
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan
| | - Hsien-Meng Chen
- Division of Infectious Diseases, Department of Internal Medicine, Changhua Christian Hospital, Changhua, Taiwan
| | - Yu-Min Chen
- Department of Pharmacy, Changhua Christian Hospital, Changhua, Taiwan
| | - Yu-Jun Chang
- Epidemiology and Biostatistics Center, Changhua Christian Hospital, Changhua, Taiwan
| | - Pao-Yen Lin
- Department of Psychiatry, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
- Chang Gung University College of Medicine, Kaohsiung, Taiwan
| | - Chih-Wei Hsu
- Department of Psychiatry, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
- Department of Computer Science and Information Engineering, National Cheng Kung University, Tainan, Taiwan
| | - Ping-Tao Tseng
- WinShine Clinics in Specialty of Psychiatry, Kaohsiung City, Taiwan
| | - Kai-Huang Lin
- Division of Critical Care Medicine, Department of Internal Medicine, Changhua Christian Hospital, Changhua, Taiwan
| | - Yu-Kang Tu
- Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
- Department of Dentistry, National Taiwan University Hospital, Taipei, Taiwan.
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A Rapid Screening Program for Histoplasmosis, Tuberculosis, and Cryptococcosis Reduces Mortality in HIV Patients from Guatemala. J Fungi (Basel) 2021; 7:jof7040268. [PMID: 33916153 PMCID: PMC8065950 DOI: 10.3390/jof7040268] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 03/25/2021] [Accepted: 03/29/2021] [Indexed: 01/15/2023] Open
Abstract
Opportunistic infections (OIs) and advanced HIV disease (AHD) contribute to HIV-related mortality. Here, we analyzed the situation of AHD and OIs in a cohort of newly diagnosed HIV patients from Guatemala. We included 2127 adult patients from 13 facilities across the country during 2017 to 2018. Patients were screened for tuberculosis (TB), nontuberculous mycobacteria (NTM), histoplasmosis, and cryptococcal disease, independently of their CD4 cell count. Of the 2127 enrolled patients, 1682 (79.1%) had a CD4 cell count available; of which 52% presented with AHD. Of the Mayan population, 65% had AHD. The overall OI incidence was 21%. Histoplasmosis was the most frequent OI (7.9%), followed by TB (7.1%); 94.4% of these infections occurred in patients with a CD4 < 350 cells/mm3. Mortality at 180 days was significantly higher in those with OIs than without OIs (29.7% vs. 5.9%, p < 0.0001). In one year, this program decreased the OI mortality by 7% and increased the OI treatment by 5.1%. Early OI diagnosis and appropriate therapy reduced OI mortality among newly diagnosed HIV patients in Guatemala. Screening for OIs should be considered in all newly diagnosed HIV patients who have a CD4 cell count < 350 cells/mm3 or those without a CD4 cell count available. To improve results, interventions such as early HIV detection and access to flucytosine and liposomal amphotericin B are required.
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38
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Ko HT, Hsu LH, Yang SY, Chen YL. Repurposing the thrombopoietin receptor agonist eltrombopag as an anticryptococcal agent. Med Mycol 2021; 58:493-504. [PMID: 31297540 DOI: 10.1093/mmy/myz077] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 05/14/2019] [Accepted: 06/18/2019] [Indexed: 01/02/2023] Open
Abstract
In this study, a Food and Drug Administration (FDA)-approved drug with previously unreported antifungal activity was investigated for suitability for use as an anticryptococcal agent. First, we screened a compound library of 1018 FDA-approved drugs against Cryptococcus neoformans. Of 52 drugs possessing anti-Cryptococcus activity, eltrombopag was chosen due to its novel activity. The susceptibility of Cryptococcus against eltrombopag was then studied by determining the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC), while the synergy of eltrombopag with other drugs was tested by fractional inhibitory concentration index (FICI). Eltrombopag had a limited spectrum of antifungal activity against C. neoformans/C. gattii species complex (MICs of 0.125 mg/l), Candida glabrata (MIC, 0.25 mg/l), and Trichophyton rubrum (MIC, 0.5 mg/l). Eltrombopag affected cryptococcal virulence factors, including capsule and biofilm formation, melanin production, and growth ability at 37°C. Further, RNA sequencing and deletion mutant library screening experiments revealed that genes involved in the calcineurin pathway, lipid biosynthesis, membrane component, and transporter genes were associated with eltrombopag. In addition, eltrombopag showed synergism with the calcineurin inhibitor FK506 (FICI < 0.5) against Cryptococcus species. In conclusion, eltrombopag exhibited excellent antifungal activity against Cryptococcus species potentially via a mode of action which interferes with virulence factors and the calcineurin pathway, indicating that eltrombopag might be usefully repurposed as an antifungal agent for treating cryptococcosis.
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Affiliation(s)
- Hao-Tai Ko
- Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, 10617 Taiwan.,Faculty of Medicine, Medical University of Lublin, Lublin, 20093 Poland
| | - Li-Hang Hsu
- Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, 10617 Taiwan
| | - Sheng-Yung Yang
- Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, 10617 Taiwan
| | - Ying-Lien Chen
- Department of Plant Pathology and Microbiology, National Taiwan University, Taipei, 10617 Taiwan
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39
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Acharya R, Khanal K, Upadhyaya P, Kafle S, Savaliya V. Diabetes mellitus as a risk factor for cryptococcal meningitis in immunocompetent. IDCases 2020; 22:e00988. [PMID: 33204630 PMCID: PMC7652783 DOI: 10.1016/j.idcr.2020.e00988] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/07/2020] [Accepted: 10/10/2020] [Indexed: 12/26/2022] Open
Abstract
Cryptococcal meningoencephalitis (CM) is one of the major causes of mortality and morbidity in immunocompromised patients estimating 650,000 deaths each year. Across the globe, CM has been occasionally seen in apparently immunocompetent patients who otherwise don’t have established risk factors. The clinical presentation of CM in immunocompetent hosts is subtle and often results in complications including persistent neurological deficits and death. We present a case of Cryptococcal neoformans meningitis in a diabetic female with no other identified risk factors. Although her clinical presentation was atypical, her clinical course was uncomplicated. The pathophysiology in immunocompetent hosts appears somewhat different, so is the clinical presentation. Since there are no separate evidence-based treatment recommendations, it is challenging to treat this group of patients. There seems to be a need for further studies for management in CM for HIV negative, non-transplant immunocompetent patients.
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Affiliation(s)
- Roshan Acharya
- Department of Medicine, Cape Fear Valley Hospital, Fayetteville, NC 28304, USA
| | - Kishor Khanal
- Department of Anesthesia and Critical Care Medicine, Nepal Mediciti Hospital, Kathmandu, Nepal
| | | | - Smita Kafle
- RN-BSN Program Student, Fayetteville State University, Fayetteville, NC 28301, USA
| | - Vipul Savaliya
- ID Care, Infectious Disease Specialist, Fayetteville, NC 28304, USA
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40
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Grizante Barião PH, Tonani L, Cocio TA, Martinez R, Nascimento É, von Zeska Kress MR. Molecular typing, in vitro susceptibility and virulence of Cryptococcus neoformans/Cryptococcus gattii species complex clinical isolates from south-eastern Brazil. Mycoses 2020; 63:1341-1351. [PMID: 32869413 DOI: 10.1111/myc.13174] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 08/17/2020] [Accepted: 08/19/2020] [Indexed: 12/17/2022]
Abstract
BACKGROUND Cryptococcus neoformans/ Cryptococcus gattii species complex is composed of encapsulated yeast species that are causative agents of cryptococcosis. The characterisation of pathogenic Cryptococcus species provides useful data for epidemiological studies as well as the clinical diagnosis and treatment of patients. OBJECTIVES This study aimed to characterise the epidemiology, antifungal susceptibility and virulence of 72 clinical strains isolated from cryptococcosis cases between 2012 and 2017 in a tertiary reference hospital in south-eastern Brazil. METHODS Species and molecular types were molecularly assessed by PCR and PCR-restriction fragment length polymorphism (RFLP) of the URA5 gene. Antifungal susceptibility testing was performed according to the CLSI protocols. The virulence was studied in a Galleria mellonella infection model. RESULTS The most frequently isolated strain was C. neoformans molecular type VNI (61/72; 84.7%), although C. neoformans molecular type VNII (3/72; 4.2%) was also isolated. Additionally, C. deuterogattii molecular type VGII (8/72; 11.1%) was present, but most frequently from non-HIV-infected patients. Non-wild-type phenotype to the antifungals was observed in 26.4% (19/72) of the C. neoformans and C. deuterogattii clinical isolates, and the latter demonstrated higher MIC to fluconazole and itraconazole than C. neoformans clinical isolates. Finally, the virulence of C. neoformans and C. deuterogattii clinical isolates was diverse in G mellonella larvae and uncorrelated with the virulence factors of melanin and capsule. CONCLUSIONS The assessment of the spread of cryptococcal species and molecular types as well as the pattern of corresponding antifungal susceptibility and virulence aids in surveil the emergence of resistant strains, ensuring more accurate management of the cryptococcal infection.
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Affiliation(s)
- Patrícia Helena Grizante Barião
- Faculdade de Ciências Farmacêuticas de Ribeirao Preto, Departamento de Analises Clinicas, Toxicologicas e Bromatologicas, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Ludmilla Tonani
- Faculdade de Ciências Farmacêuticas de Ribeirao Preto, Departamento de Analises Clinicas, Toxicologicas e Bromatologicas, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Tiago Alexandre Cocio
- Faculdade de Medicina de Ribeirao Preto, Departamento de Clinica Medica, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Roberto Martinez
- Faculdade de Medicina de Ribeirao Preto, Departamento de Clinica Medica, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Érika Nascimento
- Faculdade de Medicina de Ribeirao Preto, Departamento de Clinica Medica, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
| | - Marcia Regina von Zeska Kress
- Faculdade de Ciências Farmacêuticas de Ribeirao Preto, Departamento de Analises Clinicas, Toxicologicas e Bromatologicas, Universidade de Sao Paulo, Ribeirao Preto, Sao Paulo, Brazil
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41
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Lukas S, Crowe SJ, Law M, Kahaleh A, Addo-Atuah J, Nonyel NP, Ombengi D, Singhal M, Sultan D, Tamukong R. An Ethics-based Approach to Global Health Research Part 2: Strategies for Overcoming Logistic and Implementation Challenges. Res Social Adm Pharm 2020; 16:1580-1587. [PMID: 32811755 DOI: 10.1016/j.sapharm.2020.07.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 06/29/2020] [Accepted: 07/06/2020] [Indexed: 01/31/2023]
Abstract
With the growth of global pharmacy partnerships and collaborative research, particularly between high-income countries and low- or middle-income countries, it is necessary to establish best practices for fair and ethical collaboration and research. There is a gap in the pharmacy literature in this regard. Through this commentary, authors will present a pathway for future global health researchers including generating ideas based on mutual needs of the partnership and the community; exploring the importance of regulations including the need to conduct research and partnership projects within the confines of each participant's professional scope of practice, expertise, and licensure; describing the need to develop agreements and the components that should be included in such an agreement; discussing ethical guidelines for research planning, obtaining ethical approval, and planning for adverse events; and illustrating ethical considerations for research implementation with considerations around consent, data collection, linking patients to care after the completion of the study, and dissemination. Global examples, with a pharmacy-specific approach where applicable, within each section highlight the importance of discussion and action around ethics and equity when pursuing collaborative research, recognizing that many of these situations involve difficult decisions.
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Affiliation(s)
- Stephanie Lukas
- St. Louis College of Pharmacy, 4588 Parkview Place, St. Louis, MO, 63110, USA.
| | - Susie J Crowe
- Bill Gatton College of Pharmacy, Maple Avenue, Bldg. 7. Mountain Home, TN, USA.
| | - Miranda Law
- Howard University College of Pharmacy, 2300 4th St NW, Washington, DC, 20059, USA.
| | - Abby Kahaleh
- Roosevelt University College of Pharmacy, 1400 N Roosevelt Blvd Schaumburg, IL, 60173, USA.
| | - Joyce Addo-Atuah
- Touro College of Pharmacy, 230 W 125th Street, Room 429, New York, NY, 10027, USA.
| | - Nkem P Nonyel
- University of Maryland Eastern Shore, School of Pharmacy and Health Professions, 1 College Backbone Road, Princess Anne, MD, 21853, USA.
| | - David Ombengi
- Medical College of Wisconsin School of Pharmacy and Department of Family Medicine, 8701 Watertown Plank Road, Milwaukee, WI, 53226, USA.
| | - Mudit Singhal
- D'Youville School of Pharmacy, 320 Porter Avenue, Buffalo, NY, 14201, USA.
| | - Dawood Sultan
- Mercer University College of Health Professions, 3001 Mercer University Drive, Atlanta, GA, 30341-4155, USA.
| | - Robert Tamukong
- Mbarara University of Science &Technology, P.O.Box 1410, Mbarara, Uganda.
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42
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An Antivirulence Approach for Preventing Cryptococcus neoformans from Crossing the Blood-Brain Barrier via Novel Natural Product Inhibitors of a Fungal Metalloprotease. mBio 2020; 11:mBio.01249-20. [PMID: 32694141 PMCID: PMC7374060 DOI: 10.1128/mbio.01249-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Fungal infections like cryptococcal meningitis are difficult to resolve because of the limited therapies available. The small arsenal of antifungal drugs reflect the difficulty in finding available targets in fungi because like mammalian cells, fungi are eukaryotes. The limited efficacy, toxicity, and rising resistance of antifungals contribute to the high morbidity and mortality of fungal infections and further underscore the dire but unmet need for new antifungal drugs. The traditional approach in antifungal drug development has been to target fungal growth, but an attractive alternative is to target mechanisms of pathogenesis. An important attribute of Cryptococcus neoformans (Cn) pathogenesis is its ability to enter the central nervous system. Here, we describe a large-scale screen that identified three natural products that prevented Cn from crossing the blood-brain barrier by inhibiting the virulence factor Mpr1 without affecting the growth of Cn. We propose that compounds identified here could be further developed as antivirulence therapy that would be administered preemptively or serve as a prophylactic in patients at high risk for developing cryptococcal meningitis. Cryptococcus neoformans (Cn) is the leading cause of fungal meningitis, a deadly disease with limited therapeutic options. Dissemination to the central nervous system hinges on the ability of Cn to breach the blood-brain barrier (BBB) and is considered an attribute of Cn virulence. Targeting virulence instead of growth for antifungal drug development has not been fully exploited despite the benefits of this approach. Mpr1 is a secreted fungal metalloprotease not required for fungal growth, but rather, it functions as a virulence factor by facilitating Cn migration across the BBB. This central role for Mpr1, its extracellular location, and lack of expression in mammalian cells make Mpr1 a high-value target for an antivirulence approach aimed at developing therapeutics for cryptococcal meningitis. To test this notion, we devised a large-scale screen to identify compounds that prohibited Cn from crossing the BBB by selectively blocking Mpr1 proteolytic activity, without inhibiting the growth of Cn. A phytochemical natural product-derived library was screened to identify new molecular scaffolds of prototypes unique to a Cn microecosystem. Of the 240 pure natural products examined, 3 lead compounds, abietic acid, diosgenin, and lupinine inhibited Mpr1 proteolytic activity with 50% inhibitory concentration (IC50) values of <10 μM, displayed little to no mammalian cell toxicity, and did not affect Cn growth. Notably, the lead compounds blocked Cn from crossing the BBB, without damaging the barrier integrity, suggesting the bioactive molecules had no off-target effects. We propose that these new drug scaffolds are promising candidates for the development of antivirulence therapy against cryptococcal meningitis.
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43
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Li Y, Huang X, Qin Y, Wu H, Yan X, Chen Y. What Is the Most Appropriate Induction Regimen for the Treatment of HIV-Associated Cryptococcal Meningitis When the Recommended Regimen Is Not Available? Evidence From a Network Meta-Analysis. Front Pharmacol 2020; 11:963. [PMID: 32714189 PMCID: PMC7344322 DOI: 10.3389/fphar.2020.00963] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 06/12/2020] [Indexed: 02/06/2023] Open
Abstract
Aims Our object was to find the most appropriate, most effective, and most readily available of four induction regimens for HIV-associated cryptococcal meningitis (CM) (Regimen A: 1 week of AmB plus 5-FC followed by 1 week of fluconazole, Regimen B: 1 week of AmB plus fluconazole followed by 1 week of fluconazole, Regimen C: 2 weeks of AmB plus 5-FC, Regimen D: 2 weeks of AmB plus fluconazole), given the vast differences between resource-limited and resource-abundant settings regarding therapeutic drug accessibility, availability, and affordability for HIV-associated (CM). Methods We conducted a network meta-analysis to compare the therapeutic efficacy and safety of four different induction treatment regimens. Results The 10-week mortality of Regimen A was significantly lower than that of Regimen B and D, and the 2-week mortality of Regimen A was significantly lower than that of Regimen B. Furthermore, there were no statistically significant differences in 10-week mortality, 2-week mortality, as well as in effective fungicidal activity (EFA) over the first 2 weeks among Regimens B, C, and D. The statistical differences in adverse events between Regimen B and Regimen D, and Regimen C and Regimen D were not calculated to be significant. Conclusions Our results indicate that, 1 week of AmB plus 5-FC followed by 1 week of fluconazole is superior to the three other studied regimens, and that when 5-FC is not available, accessible, or affordable, 2 weeks of AmB plus fluconazole or 1 week of AmB plus fluconazole followed by 1 week of fluconazole is an appropriate substitution for 2 weeks of AmB plus 5-FC.
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Affiliation(s)
- Yao Li
- Division of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China
| | - Xiaojie Huang
- Center for Infectious Diseases, Beijing Youan Hospital, Capital Medical University, Beijing, China
| | - Yuanyuan Qin
- Division of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China
| | - Hao Wu
- Center for Infectious Diseases, Beijing Youan Hospital, Capital Medical University, Beijing, China
| | - Xiaofeng Yan
- Division of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China
| | - Yaokai Chen
- Division of Infectious Diseases, Chongqing Public Health Medical Center, Chongqing, China
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44
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Affiliation(s)
- Joseph N Jarvis
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, United Kingdom.,Botswana Harvard AIDS Institute Partnership, Gaborone.,Botswana UPenn Partnership, Gaborone.,Division of Infectious Diseases, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Thomas S Harrison
- Centre for Global Health, Institute for Infection and Immunity, St George's University of London, United Kingdom
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45
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Identification of Off-Patent Drugs That Show Synergism with Amphotericin B or That Present Antifungal Action against Cryptococcus neoformans and Candida spp. Antimicrob Agents Chemother 2020; 64:AAC.01921-19. [PMID: 31988099 DOI: 10.1128/aac.01921-19] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2019] [Accepted: 01/18/2020] [Indexed: 12/11/2022] Open
Abstract
Amphotericin B (AmB) is the antifungal with the strongest fungicidal activity, but its use has several limitations, mainly associated with its toxicity. Although some lipidic and liposomal formulations that present reduced toxicity are available, their price limits their application in developing countries. Flucytosine (5FC) has shown synergistic effect with AmB for treatment of some fungal infections, such as cryptococcosis, but again, its price is a limitation for its use in many regions. In the present work, we aimed to identify new drugs that have a minor effect on Cryptococcus neoformans, reducing its growth in the presence of subinhibitory concentrations of AmB. In the initial screening, we found fourteen drugs that had this pattern. Later, checkerboard assays of selected compounds, such as erythromycin, riluzole, nortriptyline, chenodiol, nisoldipine, promazine, chlorcyclizine, cloperastine, and glimepiride, were performed and all of them confirmed for their synergistic effect (fractional inhibitory concentration index [FICI] < 0.5). Additionally, toxicity of these drugs in combination with AmB was tested in mammalian cells and in zebrafish embryos. Harmless compounds, such as the antibiotic erythromycin, were found to have synergic activity with AmB, not only against C. neoformans but also against some Candida spp., in particular against Candida albicans In parallel, we identified drugs that had antifungal activity against C. neoformans and found 43 drugs that completely inhibited the growth of this fungus, such as ciclopirox and auranofin. Our results expand our knowledge about antifungal compounds and open new perspectives in the treatment of invasive mycosis based on repurposing off-patent drugs.
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46
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Billmyre RB, Applen Clancey S, Li LX, Doering TL, Heitman J. 5-fluorocytosine resistance is associated with hypermutation and alterations in capsule biosynthesis in Cryptococcus. Nat Commun 2020; 11:127. [PMID: 31913284 PMCID: PMC6949227 DOI: 10.1038/s41467-019-13890-z] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 11/29/2019] [Indexed: 12/27/2022] Open
Abstract
Patients infected with the fungal pathogen Cryptococcus are most effectively treated with a combination of 5-fluorocytosine (5FC) and amphotericin B. 5FC acts as a prodrug, which is converted into toxic 5-fluorouracil (5FU) upon uptake into fungal cells. However, the pathogen frequently develops resistance through unclear mechanisms. Here we show that resistance to 5FC in Cryptococcus deuterogattii is acquired more frequently in isolates with defects in DNA mismatch repair that confer an elevated mutation rate. We use whole genome sequencing of 16 independent isolates to identify mutations associated with 5FC resistance in vitro. We find mutations in known resistance genes (FUR1 and FCY2) and in a gene UXS1, previously shown to encode an enzyme that converts UDP-glucuronic acid to UDP-xylose for capsule biosynthesis, but not known to play a role in 5FC metabolism. Mutations in UXS1 lead to accumulation of UDP-glucuronic acid and alterations in nucleotide metabolism, which appear to suppress toxicity of both 5FC and its toxic derivative 5FU. The authors show that resistance to the antifungal 5-fluorocytosine in Cryptococcus deuterogattii is acquired more frequently in isolates with elevated mutation rate, and is associated with alterations in capsule biosynthesis and nucleotide metabolism.
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Affiliation(s)
- R Blake Billmyre
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA.,Stowers Institute for Medical Research, 1000 E 50th St., Kansas City, MO, 64110, USA
| | - Shelly Applen Clancey
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
| | - Lucy X Li
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Tamara L Doering
- Department of Molecular Microbiology, Washington University School of Medicine, Saint Louis, MO, 63110, USA
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA.
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47
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Govender NP, Meintjes G, Mangena P, Nel J, Potgieter S, Reddy D, Rabie H, Wilson D, Black J, Boulware D, Boyles T, Chiller T, Dawood H, Dlamini S, Harrison TS, Ive P, Jarvis J, Karstaedt A, Madua MC, Menezes C, Moosa MYS, Motlekar Z, Shroufi A, Stacey SL, Tsitsi M, van Cutsem G, Variava E, Venter M, Wake R. Southern African HIV Clinicians Society guideline for the prevention, diagnosis and management of cryptococcal disease among HIV-infected persons: 2019 update. South Afr J HIV Med 2019; 20:1030. [PMID: 32201629 PMCID: PMC7081625 DOI: 10.4102/sajhivmed.v20i1.1030] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 09/12/2019] [Indexed: 02/06/2023] Open
Affiliation(s)
- Nelesh P Govender
- National Institute for Communicable Diseases, a Division of the National Health Laboratory Service, Johannesburg, South Africa
- School of Pathology, University of the Witwatersrand, Johannesburg, South Africa
- Division of Medical Microbiology, University of Cape Town, Cape Town, South Africa
| | - Graeme Meintjes
- Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa
- Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Phetho Mangena
- Department of Medicine, Polokwane Hospital, Polokwane, South Africa
| | - Jeremy Nel
- Helen Joseph Hospital, University of the Witwatersrand, Johannesburg, South Africa
| | - Samantha Potgieter
- Department of Internal Medicine, University of the Free State, Bloemfontein, South Africa
| | - Denasha Reddy
- Division of Infectious Diseases, Department of Internal Medicine, Chris Hani Baragwanath Academic Hospital, University of the Witwatersrand, Johannesburg, South Africa
| | - Helena Rabie
- Department of Paediatrics, Tygerberg Hospital, Stellenbosch University, Stellenbosch, South Africa
| | - Douglas Wilson
- Department of Internal Medicine, Edendale Hospital, Pietermaritzburg, South Africa
- School of Clinical Medicine, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - John Black
- Department of Infectious Diseases, Livingstone Hospital, Port Elizabeth, South Africa
| | - David Boulware
- Department of Medicine, Centre for Infectious Diseases and Microbiology Translational Research, University of Minnesota, Minneapolis, United States
| | - Tom Boyles
- Anova Health Institute, Johannesburg, South Africa
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Tom Chiller
- Mycotic Diseases Branch, US Centres for Disease Control and Prevention, Atlanta, United States
| | - Halima Dawood
- Department of Medicine, Grey's Hospital, Pietermaritzburg, South Africa
- Caprisa, University of KwaZulu-Natal, Pietermaritzburg, South Africa
| | - Sipho Dlamini
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Groote Schuur Hospital, University of Cape Town, Cape Town, South Africa
| | - Thomas S Harrison
- Centre for Global Health, Institute of Infection and Immunity, St George's University of London, London, United Kingdom
| | - Prudence Ive
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Division of Infectious Diseases, Department of Internal Medicine, School of Clinical Medicine, Faculty of Health Sciences, Helen Joseph Hospital, Johannesburg, South Africa
| | - Joseph Jarvis
- Department of Clinical Research, Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Alan Karstaedt
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Division of Infectious Diseases, Department of Internal Medicine, Charlotte Maxeke Johannesburg Hospital, Johannesburg, South Africa
| | - Matamela C Madua
- Department of Medicine, Rob Ferreira Hospital, Mbombela, South Africa
| | - Colin Menezes
- Division of Infectious Diseases, Department of Internal Medicine, Chris Hani Baragwanath Academic Hospital, University of the Witwatersrand, Johannesburg, South Africa
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Mahomed-Yunus S Moosa
- Department of Infectious Diseases, Nelson R. Mandela School of Medicine, University of KwaZulu-Natal, Durban, South Africa
| | - Zaaheera Motlekar
- Department of Medicine, Kimberley Provincial Hospital, Kimberley, South Africa
| | - Amir Shroufi
- Mycotic Diseases Branch, US Centres for Disease Control and Prevention, Atlanta, United States
| | - Sarah Lynn Stacey
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Department of Internal Medicine, Charlotte Maxeke Johannesburg Academic Hospital, Johannesburg, South Africa
| | - Merika Tsitsi
- Division of Infectious Diseases, Department of Internal Medicine, Chris Hani Baragwanath Academic Hospital, University of the Witwatersrand, Johannesburg, South Africa
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Gilles van Cutsem
- Southern Africa Medical Unit, Médecins Sans Frontières, Cape Town, South Africa
- Centre for Infectious Disease Epidemiology and Research, University of Cape Town, Cape Town, South Africa
| | - Ebrahim Variava
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Department of Medicine, Tshepong Hospital, Klerksdorp, South Africa
| | - Michelle Venter
- Division of Infectious Diseases, Department of Internal Medicine, Chris Hani Baragwanath Academic Hospital, University of the Witwatersrand, Johannesburg, South Africa
- Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Rachel Wake
- National Institute for Communicable Diseases, a Division of the National Health Laboratory Service, Johannesburg, South Africa
- Centre for Global Health, Institute of Infection and Immunity, St George's University of London, London, United Kingdom
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48
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Ashley ED. Antifungal Drugs: Special Problems Treating Central Nervous System Infections. J Fungi (Basel) 2019; 5:E97. [PMID: 31614505 PMCID: PMC6958367 DOI: 10.3390/jof5040097] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 09/29/2019] [Accepted: 09/30/2019] [Indexed: 02/07/2023] Open
Abstract
Treating fungal infections in the central nervous system (CNS) remains a challenge despite the availability of new antifungal agents. Therapy is limited by poor understanding of the kinetic properties of antifungal drugs in the CNS compounded by lack of data for many agents. In some cases, clinical response rates do not correspond to data on drug concentrations in the cerebral spinal fluid and/or brain parenchyma. In order to better characterize the use of antifungal agents in treating CNS infections, a review of the essential principles of neuroPK are reviewed. Specific data regarding antifungal drug concentrations in the cerebral spinal fluid and brain tissue are described from human data where available. Alternative dosing regimens and the role of antifungal drug concentration monitoring in treating fungal infections in the CNS are also discussed. Having a better understanding of these key concepts will help guide clinicians in determining the best treatment courses for patients with these devastating infections.
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Affiliation(s)
- Elizabeth Dodds Ashley
- Duke Center for Antimicrobial Stewardship and Infection Prevention, Duke University School of Medicine, Durham, NC 27710, USA.
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49
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Hai TP, Van AD, Ngan NTT, Nhat LTH, Lan NPH, Vinh Chau NV, Thwaites GE, Krysan D, Day JN. The combination of tamoxifen with amphotericin B, but not with fluconazole, has synergistic activity against the majority of clinical isolates of Cryptococcus neoformans. Mycoses 2019; 62:818-825. [PMID: 31173410 PMCID: PMC6771715 DOI: 10.1111/myc.12955] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/04/2019] [Accepted: 06/04/2019] [Indexed: 02/01/2023]
Abstract
BACKGROUND Cryptococcal meningitis has fatality rates of 40%-70%, resulting in 200 000 deaths each year. The best outcomes are achieved with amphotericin combined with flucytosine but flucytosine is expensive and unavailable where most disease occurs. More effective and affordable treatments are needed. Tamoxifen, a selective oestrogen receptor modulator frequently indicated for breast cancer, has been found to have synergistic activity against the Cryptococcus neoformans type strain when combined with amphotericin or fluconazole. It is cheap, off-licence, widely available and well-tolerated, and thus a pragmatic potential treatment for cryptococcal disease. OBJECTIVES We wanted to determine the susceptibility of clinical isolates of C. neoformans to tamoxifen alone and in combination with other antifungals, to determine whether there is sufficient evidence of activity to justify a clinical trial. METHODS We used the CLSI broth microdilution protocol to test the susceptibility of 30 randomly selected clinical isolates of C. neoformans to tamoxifen, in dual combination with amphotericin, fluconazole or flucytosine, and in triple combination with amphotericin and fluconazole. Evidence of drug interactions was assessed using the fractional inhibitory concentration index. RESULTS The MIC50 and MIC90 of tamoxifen were 4 and 16 mg/L, respectively. The combination of tamoxifen and amphotericin suggested a synergistic interaction in 20 of 30 (67%) isolates. There was no interaction between tamoxifen and either fluconazole or flucytosine. Synergy was maintained in 3-Dimensional chequerboard testing. There was no evidence of antagonism. CONCLUSIONS Tamoxifen may be a useful addition to treatment with amphotericin and fluconazole for cryptococcal meningitis; a trial is justified.
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Affiliation(s)
- Trieu Phan Hai
- Oxford University Clinical Research UnitHo Chi Minh CityViet Nam
| | - Anh Duong Van
- Oxford University Clinical Research UnitHo Chi Minh CityViet Nam
| | - Nguyen Thi Thuy Ngan
- Oxford University Clinical Research UnitHo Chi Minh CityViet Nam
- Cho Ray HospitalHo Chi Minh cityViet Nam
| | | | | | | | - Guy E. Thwaites
- Oxford University Clinical Research UnitHo Chi Minh CityViet Nam
- Centre for Tropical Medicine, Nuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Damian Krysan
- Department of Pediatrics and Microbiology/ImmunologyUniversity of IowaIowa CityIowaUSA
| | - Jeremy N. Day
- Oxford University Clinical Research UnitHo Chi Minh CityViet Nam
- Centre for Tropical Medicine, Nuffield Department of MedicineUniversity of OxfordOxfordUK
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50
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Selb R, Fuchs V, Graf B, Hamprecht A, Hogardt M, Sedlacek L, Schwarz R, Idelevich EA, Becker SL, Held J, Küpper-Tetzel CP, McCormick-Smith I, Heckmann D, Gerkrath J, Han CO, Wilmes D, Rickerts V. Molecular typing and in vitro resistance of Cryptococcus neoformans clinical isolates obtained in Germany between 2011 and 2017. Int J Med Microbiol 2019; 309:151336. [PMID: 31444102 DOI: 10.1016/j.ijmm.2019.151336] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 07/05/2019] [Accepted: 07/31/2019] [Indexed: 02/07/2023] Open
Abstract
Cryptococcosis is a fungal infection of the central nervous system predominantly caused by Cryptococcus neoformans in immunocompromised patients. In several countries worldwide, up to 50% of isolates show in vitro resistance to clinically used antifungals including fluconazole. No prospective data on susceptibility to antifungal drugs are available for Germany. In this study, we characterised all C. neoformans isolates collected from individual patients' samples at the German reference laboratory for cryptococcosis 2011 and 2017 (n = 133) by multi-locus sequence typing and phenotypic drug susceptibility testing. We identified serotype A/genotype VNI isolates belonging to clonal complexes previously described from Europe, Africa, Asia and South America as the most prevalent agents of cryptococcosis in Germany. Overall, we observed minimal inhibitory concentrations (MICs) above the epidemiological cut-offs (ECVs) in 1.6% of isolates regarding fluconazole and 2.3% of isolates regarding 5-flucytosine. Here, two C. neoformans var. grubii isolates displayed decreased drug susceptibility to fluconazole, one of them additionally to 5-flucytosine. We also found 5-flucytosine MICs above the ECV for two C. neoformans var. neoformans isolates. We identified a novel mutation in the ERG11 gene which might be associated with the elevated fluconazole MIC in one of the isolates. The clinical importance of the detected in vitro resistance is documented by patient histories showing relapsed infection or primary fatal disease. Of note, sertraline demonstrated antifungal activity comparable to previous reports. Systematic collection of susceptibility data in combination with molecular typing of C. neoformans is important to comprehensively assess the spread of isolates and to understand their drug resistance patterns.
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Affiliation(s)
- Regina Selb
- European Public Health Microbiology Programme (EUPHEM), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden; Department of Infectious Diseases, Unit for Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Berlin, Germany
| | - Vidmante Fuchs
- Department of Infectious Diseases, Unit for Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Berlin, Germany
| | - Barbara Graf
- Labor Berlin - Charité Vivantes GmbH, Berlin, Germany
| | - Axel Hamprecht
- Institute for Medical Microbiology, Immunology and Hygiene, University Hospital of Cologne, Cologne, Germany
| | - Michael Hogardt
- Institute of Medical Microbiology and Infection Control, Goethe University Hospital, Frankfurt/Main, Germany
| | - Ludwig Sedlacek
- Institute for Medical Microbiology and Hospital Epidemiology, Hannover Medical School, Hannover, Germany
| | - Roman Schwarz
- MVZ Dr. Stein and colleagues, Moenchengladbach, Germany
| | - Evgeny A Idelevich
- Institute of Medical Microbiology, University Hospital Muenster, Muenster, Germany
| | - Sören L Becker
- Institute of Medical Microbiology and Hygiene, Saarland University, Homburg, Germany
| | - Jürgen Held
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen and Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
| | - Claus P Küpper-Tetzel
- Medical Department II, Infectious Diseases Unit, Goethe-University Hospital Frankfurt, Frankfurt, Germany
| | - Ilka McCormick-Smith
- Department of Infectious Diseases, Unit for Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Berlin, Germany
| | - Daniela Heckmann
- Department of Infectious Diseases, Unit for Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Berlin, Germany
| | - Jasmin Gerkrath
- Department of Infectious Diseases, Unit for Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Berlin, Germany
| | - Chang-Ok Han
- Department of Infectious Diseases, Unit for Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Berlin, Germany
| | - Dunja Wilmes
- Department of Infectious Diseases, Unit for Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Berlin, Germany
| | - Volker Rickerts
- Department of Infectious Diseases, Unit for Mycotic and Parasitic Agents and Mycobacteria, Robert Koch-Institute, Berlin, Germany.
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