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Kumari D, Sachivkina N, Pasrija R. Investigation of the influence of pH and temperature on melanization and survival under oxidative stress in Cryptococcus neoformans. Arch Microbiol 2024; 206:355. [PMID: 39017938 DOI: 10.1007/s00203-024-04080-7] [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: 04/16/2024] [Revised: 07/04/2024] [Accepted: 07/08/2024] [Indexed: 07/18/2024]
Abstract
Cryptococcus neoformans is an opportunistic pathogenic fungus that produces melanin during infection, an important virulence factor in Cryptococcal infections that enhances the ability of the fungus to resist immune defense. This fungus can synthesize melanin from a variety of substrates, including L-DOPA (L-3,4-dihydroxyphenylalanine). Since melanin protects the fungus from various stress factors such as oxidative, nitrosative, extreme heat and cold stress; we investigated the effects of environmental conditions on melanin production and survival. In this study, we investigated the effects of different pH values (5.6, 7.0 and 8.5) and temperatures (30 °C and 37 °C) on melanization and cell survival using a microtiter plate-based melanin production assay and an oxidative stress assay, respectively. In addition, the efficacy of compounds known to inhibit laccase involved in melanin synthesis, i.e., tunicamycin, β-mercaptoethanol, dithiothreitol, sodium azide and caspofungin on melanization was evaluated and their sensitivity to temperature and pH changes was measured. The results showed that melanin content correlated with pH and temperature changes and that pH 8.5 and 30 °C, were best for melanin production. Besides that, melanin production protects the fungal cells from oxidative stress induced by hydrogen peroxide. Thus, changes in pH and temperature drastically alter melanin production in C. neoformans and it correlates with the fungal survival. Due to the limited antifungal repertoire and the development of resistance in cryptococcal infections, the investigation of environmental conditions in the regulation of melanization and survival of C. neoformans could be useful for future research and clinical phasing.
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Affiliation(s)
- Deepika Kumari
- Department of Biochemistry, Maharshi Dayanand University, Rohtak, 124001, India
| | - Nadezhda Sachivkina
- Department of Microbiology, Peoples' Friendship University of Russia, Moscow, 117198, Russia
| | - Ritu Pasrija
- Department of Biochemistry, Maharshi Dayanand University, Rohtak, 124001, India.
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2
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De Jesus DFF, De Freitas ALD, De Oliveira IM, De Almeida LC, Bastos RW, Spadari CDC, Melo ASDA, Santos DDA, Costa-Lotufo LV, Reis FCG, Rodrigues ML, Stefani HA, Ishida K. Organoselenium Has a Potent Fungicidal Effect on Cryptococcus neoformans and Inhibits the Virulence Factors. Antimicrob Agents Chemother 2023; 67:e0075922. [PMID: 36815840 PMCID: PMC10019174 DOI: 10.1128/aac.00759-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 01/14/2023] [Indexed: 02/24/2023] Open
Abstract
Cryptococcosis therapy is often limited by toxicity problems, antifungal tolerance, and high costs. Studies approaching chalcogen compounds, especially those containing selenium, have shown promising antifungal activity against pathogenic species. This work aimed to evaluate the in vitro and in vivo antifungal potential of organoselenium compounds against Cryptococcus neoformans. The lead compound LQA_78 had an inhibitory effect on C. neoformans planktonic cells and dispersed cells from mature biofilms at similar concentrations. The fungal growth inhibition led to an increase in budding cells arrested in the G2/M phase, but the compound did not significantly affect structural cell wall components or chitinase activity, an enzyme that regulates the dynamics of the cell wall. The compound also inhibited titan cell (Tc) and enlarged capsule yeast (NcC) growth and reduced the body diameter and capsule thickness associated with increased capsular permeability of both virulent morphotypes. LQA_78 also reduced fungal melanization through laccase activity inhibition. The fungicidal activity was observed at higher concentrations (16 to 64 μg/mL) and may be associated with augmented plasma membrane permeability, ROS production, and loss of mitochondrial membrane potential. While LQA_78 is a nonhemolytic compound, its cytotoxic effects were cell type dependent, exhibiting no toxicity on Galleria mellonella larvae at a dose ≤46.5 mg/kg. LQA_78 treatment of larvae infected with C. neoformans effectively reduced the fungal burden and inhibited virulent morphotype formation. To conclude, LQA_78 displays fungicidal action and inhibits virulence factors of C. neoformans. Our results highlight the potential use of LQA_78 as a lead molecule for developing novel pharmaceuticals for treating cryptococcosis.
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Affiliation(s)
| | | | | | | | - Rafael Wesley Bastos
- Center of Biosciences, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil
| | | | | | - Daniel de Assis Santos
- Institute of Biomedical Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, Brazil
| | | | - Flavia C. G. Reis
- Carlos Chagas Institute, Oswaldo Cruz Foundation, Curitiba, Brazil
- Center for Technological Development in Health (CDTS), Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Marcio L. Rodrigues
- Carlos Chagas Institute, Oswaldo Cruz Foundation, Curitiba, Brazil
- Institute of Microbiology Paulo de Góes, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | | | - Kelly Ishida
- Institute of Biomedical Sciences, University of São Paulo (USP), São Paulo, Brazil
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3
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Smith DFQ, Mudrak NJ, Zamith-Miranda D, Honorato L, Nimrichter L, Chrissian C, Smith B, Gerfen G, Stark RE, Nosanchuk JD, Casadevall A. Melanization of Candida auris Is Associated with Alteration of Extracellular pH. J Fungi (Basel) 2022; 8:1068. [PMID: 36294632 PMCID: PMC9604884 DOI: 10.3390/jof8101068] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 10/05/2022] [Accepted: 10/07/2022] [Indexed: 11/29/2022] Open
Abstract
Candida auris is a recently emerged global fungal pathogen, which causes life-threatening infections, often in healthcare settings. C. auris infections are worrisome because the fungus is often resistant to multiple antifungal drug classes. Furthermore, C. auris forms durable and difficult to remove biofilms. Due to the relatively recent, resilient, and resistant nature of C. auris, we investigated whether it produces the common fungal virulence factor melanin. Melanin is a black-brown pigment typically produced following enzymatic oxidation of aromatic precursors, which promotes fungal virulence through oxidative stress resistance, mammalian immune response evasion, and antifungal peptide and pharmaceutical inactivation. We found that certain strains of C. auris oxidized L-DOPA and catecholamines into melanin. Melanization occurred extracellularly in a process mediated by alkalinization of the extracellular environment, resulting in granule-like structures that adhere to the fungus' external surface. C. auris had relatively high cell surface hydrophobicity, but there was no correlation between hydrophobicity and melanization. Melanin protected the fungus from oxidative damage, but we did not observe a protective role during infection of macrophages or Galleria mellonella larvae. In summary, C. auris alkalinizes the extracellular medium, which promotes the non-enzymatic oxidation of L-DOPA to melanin that attaches to its surface, thus illustrating a novel mechanism for fungal melanization.
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Affiliation(s)
- Daniel F. Q. Smith
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
| | - Nathan J. Mudrak
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
- Krieger School of Arts & Science, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Daniel Zamith-Miranda
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
| | - Leandro Honorato
- Laboratório de Glicobiologia de Eucariotos, Departamento de Microbiologia Geral, Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
| | - Leonardo Nimrichter
- Laboratório de Glicobiologia de Eucariotos, Departamento de Microbiologia Geral, Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-901, Brazil
| | - Christine Chrissian
- Department of Chemistry and Biochemistry, City College of New York and CUNY Institute for Macromolecular Assemblies, The City University of New York, New York, NY 10031, USA
| | - Barbara Smith
- Institute for Basic Biomedical Sciences Microscope Facility, The Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Gary Gerfen
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
| | - Ruth E. Stark
- Department of Chemistry and Biochemistry, City College of New York and CUNY Institute for Macromolecular Assemblies, The City University of New York, New York, NY 10031, USA
| | - Joshua D. Nosanchuk
- Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, Bronx, New York, NY 10461, USA
| | - Arturo Casadevall
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, The Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA
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In silico and in vitro studies on the inhibition of laccase activity by Ellagic acid: Implications in drug designing for the treatment of Cryptococcal infections. Int J Biol Macromol 2022; 209:642-654. [PMID: 35421416 DOI: 10.1016/j.ijbiomac.2022.04.060] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 03/30/2022] [Accepted: 04/08/2022] [Indexed: 01/14/2023]
Abstract
In recent years, the increased frequency of drug-resistant strains of Cryptococcus neoformans has depleted our antifungal armory. In the present study, we investigated the inhibitory potential of ellagic acid (EA) against C. neoformans laccase through in silico and in vitro studies. For the first time, a homology modelling was established to model laccase and modelled protein served as a receptor for docking EA. Thermodynamic stability of the docked complex was ascertained by molecular dynamics simulation (MD). The analysis of root mean square deviation and fluctuation of alpha carbons of protein justifies the stability of the bound EA in the binding pocket of laccase. Frontier molecular orbitals of the EA was studied by density functional theory-based optimization by using the Lee-Yang-Parr correlation functional (B3LYP) approach. Negative values of the highest occupied/unoccupied molecular orbitals (HOMO/LUMO) indicated that laccase with EA forms a stable complex. Interestingly, EA inhibited laccase activity both in vitro and in yeast cells of C. neoformans. Moreover, EA treatment remarkably inhibited the proliferation of C. neoformans inside macrophages. The findings of the present study unveil the molecular basis of the interactions of laccase with EA, which may prove to be beneficial for designing laccase inhibitors as potential anti-cryptococcal agents.
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Clinical analysis in immunocompetent and immunocompromised patients with pulmonary cryptococcosis in western China. Sci Rep 2020; 10:9387. [PMID: 32523003 PMCID: PMC7287058 DOI: 10.1038/s41598-020-66094-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 05/15/2020] [Indexed: 02/05/2023] Open
Abstract
Cryptococcosis is a systemic infection and it may occur in immunocompromised and immunocompetent hosts. In order to better understand the clinical characteristics of patients with PC in different immune status, we retrospectively investigated the clinical, radiological, and treatment profiles of immunocompetent and immunocompromised patients with PC during a 10-year period (2008–2017). As a result, out of 136 patients, 94 (69.1%) were immunocompromised hosts. For the PC patients without CNS involvement, higher percentage of immunocompetent patients (39.5%, 15/38) had asymptomatic presentation than immunocompromised patients (6.3%, 3/48) (P < 0.05). Multiple pulmonary nodules (72.7%, 56/77), ground-glass attenuation/interstitial changes (94.4%, 17/18) and cavitation (88.6%, 31/35) were significantly frequent in immunocompromised patients (P < 0.05). A total of 47 patients were misdiagnosed as tuberculosis or tumors based on CT signs. PC was likely to be misdiagnosed as tuberculosis in immunocompromised patients (88.2%, 15/17), and tumor was more likely to be considered in immunocompetent patients (43.3%, 13/30). Immunocompetent patients accounted for 80% (24/30) of patients with definite diagnosis on surgical lung biopsy. Fluconazole monotherapy can achieve good clinical outcome in most PC patients without central nervous system (CNS) involvement (91.5%, 54/59). After 3 months of treatment, 92.7% (38/41) patients have improved imaging findings. In conclusion, PC has diverse imaging manifestations and it is easily misdiagnosed. Lobectomy should be carefully selected in immunocompetent patients with a single lung lesion. Fluconazole monotherapy is preferred for PC patients without CNS involvement.
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Krummenauer ME, Lopes W, Garcia AWA, Schrank A, Gnoatto SCB, Kawano DF, Vainstein MH. A Highly Active Triterpene Derivative Capable |of Biofilm Damage to Control Cryptococcus spp. Biomolecules 2019; 9:E831. [PMID: 31817559 PMCID: PMC6995603 DOI: 10.3390/biom9120831] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 12/03/2019] [Accepted: 12/04/2019] [Indexed: 12/13/2022] Open
Abstract
Cryptococcus neoformans is an encapsulated yeast responsible for more than 180,000 deaths per year. The standard therapeutic approach against cryptococcosis is a combination of amphotericin B with flucytosine. In countries where cryptococcosis is most prevalent, 5-fluorocytosine is rarely available, and amphotericin B requires intravenous administration. C. neoformans biofilm formation is related to increased drug resistance, which is an important outcome for hospitalized patients. Here, we describe new molecules with anti-cryptococcal activity. A collection of 66 semisynthetic derivatives of ursolic acid and betulinic acid was tested against mature biofilms of C. neoformans at 25 µM. Out of these, eight derivatives including terpenes, benzazoles, flavonoids, and quinolines were able to cause damage and eradicate mature biofilms. Four terpene compounds demonstrated significative growth inhibition of C. neoformans. Our study identified a pentacyclic triterpenoid derived from betulinic acid (LAFIS13) as a potential drug for anti-cryptococcal treatment. This compound appears to be highly active with low toxicity at minimal inhibitory concentration and capable of biofilm eradication.
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Affiliation(s)
- Maria E. Krummenauer
- Centro de Biotecnologia, PPGBCM, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91501-970, Brazil; (M.E.K.); (W.L.); (A.W.A.G.); (A.S.)
| | - William Lopes
- Centro de Biotecnologia, PPGBCM, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91501-970, Brazil; (M.E.K.); (W.L.); (A.W.A.G.); (A.S.)
| | - Ane W. A. Garcia
- Centro de Biotecnologia, PPGBCM, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91501-970, Brazil; (M.E.K.); (W.L.); (A.W.A.G.); (A.S.)
| | - Augusto Schrank
- Centro de Biotecnologia, PPGBCM, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91501-970, Brazil; (M.E.K.); (W.L.); (A.W.A.G.); (A.S.)
| | - Simone C. B. Gnoatto
- Faculdade de Farmácia, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 90610-000, Brazil;
| | - Daniel F. Kawano
- Faculdade de Ciências Farmacêuticas, Universidade Estadual de Campinas, Campinas, São Paulo 13083-871, Brazil;
| | - Marilene H. Vainstein
- Centro de Biotecnologia, PPGBCM, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul 91501-970, Brazil; (M.E.K.); (W.L.); (A.W.A.G.); (A.S.)
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7
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Zimbres ACG, Reuwsaat JCV, Barcellos VA, Joffe LS, Fonseca FL, Staats CC, Schrank A, Kmetzsch L, Vainstein MH, Rodrigues ML. Pharmacological inhibition of pigmentation inCryptococcus. FEMS Yeast Res 2018; 19:5173039. [DOI: 10.1093/femsyr/foy119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 11/06/2018] [Indexed: 11/13/2022] Open
Affiliation(s)
- Ana Claudia G Zimbres
- Centro de Desenvolvimento Tecnológico em Saúde (CDTS), Fundação Oswaldo Cruz, Rio de Janeiro 21941-902, Brazil
- Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
| | - Julia C V Reuwsaat
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90040-060, Brazil
| | - Vanessa A Barcellos
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90040-060, Brazil
| | - Luna S Joffe
- Centro de Desenvolvimento Tecnológico em Saúde (CDTS), Fundação Oswaldo Cruz, Rio de Janeiro 21941-902, Brazil
| | - Fernanda L Fonseca
- Centro de Desenvolvimento Tecnológico em Saúde (CDTS), Fundação Oswaldo Cruz, Rio de Janeiro 21941-902, Brazil
| | - Charley C Staats
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90040-060, Brazil
- Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90040-060, Brazil
| | - Augusto Schrank
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90040-060, Brazil
- Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90040-060, Brazil
| | - Livia Kmetzsch
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90040-060, Brazil
- Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90040-060, Brazil
| | - Marilene H Vainstein
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90040-060, Brazil
- Departamento de Biologia Molecular e Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre 90040-060, Brazil
| | - Marcio L Rodrigues
- Instituto de Microbiologia Paulo de Góes (IMPG), Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, Brazil
- Laboratory of Gene Expression Regulation (LabReg), Instituto Carlos Chagas, Fundação Oswaldo Cruz (Fiocruz), Curitiba, PR 81310-020, Brazil
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Bassetti M, Mikulska M, Nicco E, Viscoli C. Pulmonary Cryptococcosis with Severe Eosinophilia in an Immunocompetent Patient. J Chemother 2013; 22:366-7. [DOI: 10.1179/joc.2010.22.5.366] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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9
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Assessment of efficacy of antifungals against Aspergillus fumigatus: value of real-time bioluminescence imaging. Antimicrob Agents Chemother 2013; 57:3046-59. [PMID: 23587947 DOI: 10.1128/aac.01660-12] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Aspergillus fumigatus causes life-threatening infections, especially in immunocompromised patients. Common drugs for therapy of aspergillosis are polyenes, azoles, and echinocandins. However, despite in vitro efficacy of these antifungals, treatment failure is frequently observed. In this study, we established bioluminescence imaging to monitor drug efficacy under in vitro and in vivo conditions. In vitro assays confirmed the effectiveness of liposomal amphotericin B, voriconazole, and anidulafungin. Liposomal amphotericin B and voriconazole were fungicidal, whereas anidulafungin allowed initial germination of conidia that stopped elongation but allowed the conidia to remain viable. In vivo studies were performed with a leukopenic murine model. Mice were challenged by intranasal instillation with a bioluminescent reporter strain (5 × 10(5) and 2.5 × 10(5) conidia), and therapy efficacies of liposomal amphotericin B, voriconazole, and anidulafungin were monitored. For monotherapy, the highest treatment efficacy was observed with liposomal amphotericin B, whereas the efficacies of voriconazole and anidulafungin were strongly dependent on the infectious dose. When therapy efficacy was studied with different drug combinations, all combinations improved the rate of treatment success compared to that with monotherapy. One hundred percent survival was obtained for treatment with a combination of liposomal amphotericin B and anidulafungin, which prevented not only pulmonary infections but also infections of the sinus. In conclusion, combination therapy increases treatment success, at least in the murine infection model. In addition, our novel approach based on real-time imaging enables in vivo monitoring of drug efficacy in different organs during therapy of invasive aspergillosis.
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van Belkum A, Fahal A, van de Sande WWJ. Mycetoma caused by Madurella mycetomatis: a completely neglected medico-social dilemma. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2013; 764:179-89. [PMID: 23654067 DOI: 10.1007/978-1-4614-4726-9_15] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Mycetoma is a debilitating disease with a highly particular geographical distribution. The mycetoma belt circles the entire world just above the equator and defines the region with the highest prevalence and incidence. Although the disease is seen in Central America, India and all across Africa, Sudan seems to be the homeland of mycetoma. Mycetoma is an infectious disease caused either by bacteria (actinomycetoma) or true fungi (eumycetoma). In Sudan most cases are caused by the fungal species Madurella mycetomatis. The precise natural habitat of this fungus is still an enigma, but its DNA can easily be found in soil and plant samples in endemic areas. Although the entire human population in these areas are in regular contact with the fungus, most individuals are unaffected. Thus mycetoma is an ideal clinical and experimental model system for the study of host-pathogen interactions. Also, given its relative importance locally, improvements in clinical and laboratory diagnostics and knowledge of the epidemiology of the disease are badly needed. This chapter describes the current state of affairs in the field of eumycetoma caused by M. mycetomatis. The value of laboratory research on this disease and future perspective for control and prevention of the infection are discussed.
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Affiliation(s)
- Alex van Belkum
- BioMérieux, Microbiology Unit, La Balme-Les-Grottes, France.
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Cryptococcus gattii: a Review of the Epidemiology, Clinical Presentation, Diagnosis, and Management of This Endemic Yeast in the Pacific Northwest. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.clinmicnews.2011.11.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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12
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Silva FD, Rossi DCP, Martinez LR, Frases S, Fonseca FL, Campos CBL, Rodrigues ML, Nosanchuk JD, Daffre S. Effects of microplusin, a copper-chelating antimicrobial peptide, against Cryptococcus neoformans. FEMS Microbiol Lett 2011; 324:64-72. [PMID: 22092765 DOI: 10.1111/j.1574-6968.2011.02386.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 07/15/2011] [Accepted: 08/15/2011] [Indexed: 11/28/2022] Open
Abstract
Microplusin is an antimicrobial peptide isolated from the cattle tick Rhipicephalus (Boophilus) microplus. Its copper-chelating ability is putatively responsible for its bacteriostatic activity against Micrococcus luteus as microplusin inhibits respiration in this species, which is a copper-dependent process. Microplusin is also active against Cryptococcus neoformans (MIC(50) = 0.09 μM), the etiologic agent of cryptococcosis. Here, we show that microplusin is fungistatic to C. neoformans and this inhibitory effect is abrogated by copper supplementation. Notably, microplusin drastically altered the respiratory profile of C. neoformans. In addition, microplusin affects important virulence factors of this fungus. We observed that microplusin completely inhibited fungal melanization, and this effect correlates with the inhibition of the related enzyme laccase. Also, microplusin significantly inhibited the capsule size of C. neoformans. Our studies reveal, for the first time, a copper-chelating antimicrobial peptide that inhibits respiration and growth of C. neoformans and modifies two major virulence factors: melanization and formation of a polysaccharide capsule. These features suggest that microplusin, or other copper-chelation approaches, may be a promising therapeutic for cryptococcosis.
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Affiliation(s)
- Fernanda D Silva
- Departamento de Parasitologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo-SP, Brazil
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Ptilomycalin A inhibits laccase and melanization in Cryptococcus neoformans. Bioorg Med Chem 2011; 19:6654-7. [PMID: 21715177 DOI: 10.1016/j.bmc.2011.05.041] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 04/23/2011] [Accepted: 05/23/2011] [Indexed: 11/22/2022]
Abstract
The antifungal spirocyclic guanidine alkaloid, ptilomycalin A, from marine sponge Monanchora arbuscula, inhibits melanogenesis of Cryptococcus neoformans in vitro through inhibition of biosynthesis of laccase in the melanin biosynthetic pathway with an IC(50) of 7.3 μM.
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Combination Efficacy of Voriconazole and Amphotericin B in the Experimental Disease in Immunodeficient Mice Caused by Fluconazole-resistant Cryptococcus neoformans. Mycopathologia 2010; 171:261-6. [DOI: 10.1007/s11046-010-9375-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 10/08/2010] [Indexed: 10/18/2022]
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15
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Gómez-López A, Zaragoza O, Rodríguez-Tudela JL, Cuenca-Estrella M. Pharmacotherapy of yeast infections. Expert Opin Pharmacother 2009; 9:2801-16. [PMID: 18937613 DOI: 10.1517/14656566.9.16.2801] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The rise of immunocompromised individuals in our society has provoked a significant emergence in the number of patients affected by opportunistic pathogenic yeast. The microorganisms with a major clinical incidence are species from the genera Candida (especially Candida albicans) and Cryptococcus (particularly Cryptococcus neoformans), although there has been a significant increase in other pathogenic yeasts, such as Trichosporon spp. and Rhodotorula spp. In addition, there are an increasing number of patients infected by yeasts that were not previously considered as pathogenic, such as Saccharomyces cerevisiae. The management of these infections is complicated and is highly dependent on the susceptibility profile not only of the species but also of the strain. The available antifungal compounds belong mainly to the polyene, azole and candin families, which show a distinct spectrum of activity. This review summarizes the current knowledge about the use of the main antifungals for treating infections caused by the yeast species with the most significant clinical relevance, including the susceptibility profiles exhibited by these species in vitro.
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Affiliation(s)
- Alicia Gómez-López
- Instituto de Salud Carlos III, Servicio de Micología, Centro Nacional de Microbiología, Carretera Majadahonda-Pozuelo, Km2, Majadahonda 28220, Madrid, Spain
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Current awareness on yeast. Yeast 2008. [DOI: 10.1002/yea.1563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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