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Zhao Q, Zou Y, Guo J, Yu S, Chai X, Hu H, Wu Q. Synthesis and antifungal activities of N-glycosylated derivatives of Tunicyclin D, an antifungal octacyclopeptide. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.05.077] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Brazilian guidelines for the management of candidiasis - a joint meeting report of three medical societies: Sociedade Brasileira de Infectologia, Sociedade Paulista de Infectologia and Sociedade Brasileira de Medicina Tropical. Braz J Infect Dis 2013; 17:283-312. [PMID: 23693017 PMCID: PMC9427385 DOI: 10.1016/j.bjid.2013.02.001] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Accepted: 02/16/2013] [Indexed: 01/07/2023] Open
Abstract
Candida infections account for 80% of all fungal infections in the hospital environment, including bloodstream, urinary tract and surgical site infections. Bloodstream infections are now a major challenge for tertiary hospitals worldwide due to their high prevalence and mortality rates. The incidence of candidemia in tertiary public hospitals in Brazil is approximately 2.5 cases per 1000 hospital admissions. Due to the importance of this infection, the authors provide a review of the diversity of the genus Candida and its clinical relevance, the therapeutic options and discuss the treatment of major infections caused by Candida. Each topography is discussed with regard to epidemiological, clinical and laboratory diagnostic and therapeutic recommendations based on levels of evidence.
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Yu S, Wang N, Chai X, Wang B, Cui H, Zhao Q, Zou Y, Sun Q, Meng Q, Wu Q. Synthesis and antifungal activity of the novel triazole derivatives containing 1,2,3-triazole fragment. Arch Pharm Res 2013; 36:1215-22. [DOI: 10.1007/s12272-013-0063-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 08/08/2012] [Indexed: 11/29/2022]
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Brazilian guidelines for the management of candidiasis: a joint meeting report of three medical societies – Sociedade Brasileira de Infectologia, Sociedade Paulista de Infectologia, Sociedade Brasileira de Medicina Tropical. Braz J Infect Dis 2012. [DOI: 10.1016/s1413-8670(12)70336-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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Combination of voriconazole and anidulafungin for treatment of triazole-resistant aspergillus fumigatus in an in vitro model of invasive pulmonary aspergillosis. Antimicrob Agents Chemother 2012; 56:5180-5. [PMID: 22825124 DOI: 10.1128/aac.01111-12] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Voriconazole is a first-line agent for the treatment of invasive pulmonary aspergillosis. Isolates with elevated voriconazole MICs are increasingly being seen, and the optimal treatment regimen is not defined. We investigated whether the combination of voriconazole with anidulafungin may be beneficial for the treatment of A. fumigatus strains with elevated voriconazole MICs. We used an in vitro model of the human alveolus to define the exposure-response relationships for a wild-type strain (voriconazole MIC, 0.5 mg/liter) and strains with defined molecular mechanisms of triazole resistance (MICs, 4 to 16 mg/liter). All strains had anidulafungin minimum effective concentrations (MECs) of 0.0078 mg/liter. Exposure-response relationships were estimated using galactomannan as a biomarker. Concentrations of voriconazole and anidulafungin were measured using high-performance liquid chromatography (HPLC). The interaction of voriconazole and anidulafungin was described using the Greco model. Fungal growth was progressively inhibited with higher drug exposures of voriconazole. Strains with elevated voriconazole MICs required proportionally greater voriconazole exposures to achieve a comparable antifungal effect. Galactomannan concentrations were only marginally reduced by anidulafungin monotherapy. An additive effect between voriconazole and anidulafungin was apparent. In conclusion, the addition of anidulafungin does not markedly alter the exposure-response relationship of voriconazole. A rise in serum galactomannan during combination therapy with voriconazole and anidulafungin should be interpreted as treatment failure and not attributed to a paradoxical reaction related to echinocandin treatment.
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Guo J, Hu H, Zhao Q, Wang T, Zou Y, Yu S, Wu Q, Guo Z. Synthesis and Antifungal Activities of Glycosylated Derivatives of the Cyclic Peptide Fungicide Caspofungin. ChemMedChem 2012; 7:1496-503. [DOI: 10.1002/cmdc.201200214] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Revised: 05/18/2012] [Indexed: 11/07/2022]
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Total synthesis and structure–activity relationships of caspofungin-like macrocyclic antifungal lipopeptides. Tetrahedron 2012. [DOI: 10.1016/j.tet.2012.02.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Yao J, Liu H, Zhou T, Chen H, Miao Z, Sheng C, Zhang W. Total synthesis and structure-activity relationships of new echinocandin-like antifungal cyclolipohexapeptides. Eur J Med Chem 2012; 50:196-208. [PMID: 22348827 DOI: 10.1016/j.ejmech.2012.01.054] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 01/27/2012] [Accepted: 01/27/2012] [Indexed: 11/30/2022]
Abstract
A series of new echinocandin-like cyclolipohexapeptides were designed and total synthesized via solution phase [3 + 3]-segment coupling strategy with an attempt to improve antifungal activity. The designed compounds showed potent antifungal activities with broad spectrum. In particular, 11 compounds (i.e. 28a-e, 28g, 28i-j, 29a, 29c and 29e) showed better in vitro antifungal activities against Candida albicans or Aspergillus fumigatus than caspofungin. Moreover, the synthesized compounds provided new SAR information for the echinocandins. The findings in this work suggested that the "left" tripeptide segment of cyclolipohexapeptide scaffold might be a hydrophilic structural motif, whereas the "right" lipopeptide segment was preferred as a hydrophobic core. The amino acid component of the cyclolipohexapeptide scaffold could significantly affect the SAR of the side chains.
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Affiliation(s)
- Jianzhong Yao
- Department of Medicinal Chemistry, School of Pharmacy, Second Military Medical University, Shanghai 200433, China
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Synthesis and antifungal activity of novel triazole derivatives. Arch Pharm Res 2011; 34:1649-56. [DOI: 10.1007/s12272-011-1009-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2011] [Revised: 06/27/2011] [Accepted: 07/13/2011] [Indexed: 11/25/2022]
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Efficacy of caspofungin in a juvenile mouse model of central nervous system candidiasis. Antimicrob Agents Chemother 2011; 55:3491-7. [PMID: 21518846 DOI: 10.1128/aac.01328-10] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Neonatal candidiasis is an increasingly common occurrence causing significant morbidity and mortality and a higher risk of dissemination to the central nervous system (CNS) than that seen with older patients. The current understanding of optimal antifungal therapy in this setting is limited. We have developed a model of disseminated candidiasis with CNS involvement in juvenile mice to assess the efficacy of the echinocandin caspofungin relative to amphotericin B (AmB). Juvenile mice were inoculated intravenously with 5.64 × 10(4) CFU of Candida albicans MY1055. Treatment with caspofungin at 1, 2, 4, and 8 mg/kg of body weight/day, AmB at 1 mg/kg/day, or a vehicle control (VC) was initiated 30 h after infection and continued for 7 days. Pharmacokinetic parameters for caspofungin were also determined. Culture and histology showed evidence of disseminated candidiasis with multifocal encephalitis at the start of antifungal therapy. Survival was 100% in all treated groups, while mortality was 100% in the VC by day 11 after infection. By day 5, all mice in the caspofungin treatment (four doses) groups showed reductions in kidney and brain burden relative to the VC, while AmB treatment reduced kidney burden but gave no reduction of brain fungal burden. Systemic levels of caspofungin were similar in infected and uninfected mice, while brain levels were higher in infected animals. In this juvenile mouse model, caspofungin demonstrated dose-dependent activity, equivalent to or better than that of AmB at 1 mg/kg, against disseminated candidiasis with CNS involvement.
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Abstract
Micafungin is the second approved antifungal agent in the echinocandin series and is now used worldwide in chemotherapy for life-threatening fungal infections. It is water-soluble and is semi-synthesized from the acylated cyclic hexapeptide FR901379, a natural product from the fungus Coleophoma empetri F-11899, through enzymatic deacylation of FR901379, followed by chemical reacylation with the optimized N-acyl side chain. The water solubility of micafungin is ascribed to a sulfate moiety in the molecule. This feature differentiates micafungin from other echinocandin members. Micafungin is a potent inhibitor of 1,3-beta-glucan synthase, an enzyme necessary for cell-wall synthesis of several fungal pathogens.
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Correlating echinocandin MIC and kinetic inhibition of fks1 mutant glucan synthases for Candida albicans: implications for interpretive breakpoints. Antimicrob Agents Chemother 2008; 53:112-22. [PMID: 18955538 DOI: 10.1128/aac.01162-08] [Citation(s) in RCA: 198] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A detailed kinetic characterization of echinocandin inhibition was performed for mutant 1,3-beta-d-glucan synthase enzymes from clinical isolates of Candida albicans with nine different FKS1 mutations resulting in high MICs. Among 14 mutant Fks1p enzymes studied, the kinetic parameters 50% inhibitory concentration and K(i) increased 50-fold to several thousandfold relative to those for the wild type. Enzymes with mutations at Ser645 (S645P, S645Y, and S645F) within hot spot 1 showed the most prominent decrease in sensitivity, while those with mutations at the N- and C-terminal ends of hot spot 1 generally retained greater sensitivity to all three drugs. Kinetic inhibitions by caspofungin, micafungin, and anidulafungin were comparable among the fks1 mutant enzymes, although absolute values did vary with specific mutations. Amino acid substitutions in Fks1p did not alter K(m) values, although some mutations decreased the V(max). Given the association of FKS1 mutations with clinical resistance, an evaluation of the kinetic parameters for the inhibition of mutant 1,3-beta-D-glucan synthase as a function of the MIC enabled an independent evaluation of the recently adopted susceptibility breakpoint for echinocandin drugs. Overall, a breakpoint MIC of >or=2 microg/ml for caspofungin captured nearly 100% of fks1 C. albicans strains when a kinetic inhibition rise threshold of <or=50-fold for the K(i) was used as a measure of susceptibility. A similar MIC breakpoint for micafungin and anidulafungin was less inclusive, and a projected MIC of >or=0.5 microg/ml was required for >95% coverage of clinical isolates. However, when MIC determinations were performed in the presence of 50% serum, all fks1 mutants showed MIC values of >or=2 microg/ml for the three echinocandin drugs. The 1,3-beta-D-glucan synthase kinetic inhibition data support the proposed susceptibility breakpoint for caspofungin in C. albicans, but a lower susceptibility breakpoint (<or=0.5 microg/ml) may be more appropriate for anidulafungin and micafungin. Overall, the data indicate that MIC testing with caspofungin may serve as a surrogate marker for resistance among the class of echinocandin drugs.
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Hohl TM, Feldmesser M, Perlin DS, Pamer EG. Caspofungin modulates inflammatory responses to Aspergillus fumigatus through stage-specific effects on fungal beta-glucan exposure. J Infect Dis 2008; 198:176-85. [PMID: 18500928 DOI: 10.1086/589304] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Echinocandins target fungal beta-1,3 glucan synthesis and are used clinically to treat invasive aspergillosis. Although echinocandins do not completely inhibit in vitro growth of Aspergillus fumigatus, they do induce morphological changes in fungal hyphae. Because beta-1,3 glucans activate host antifungal pathways via the Dectin-1 receptor, we investigated the effect of echinocandins on inflammatory responses to A. fumigatus. Caspofungin- or micafungin-treated conidia and germlings induced less secretion of tumor necrosis factor (TNF) and CXCL2 by macrophages than did their untreated counterparts. Diminished secretion of TNF and CXCL2 correlated with diminished beta-glucan exposure on echinocandin-treated germ tubes. In contrast to treated conidia and germlings, echinocandin-treated hyphae stimulated increased release of TNF and CXCL2 by macrophages and demonstrated intense staining with a beta-glucan-specific antibody, particularly at hyphal tips. Our experiments demonstrate that echinocandin-induced morphological changes in A. fumigatus hyphae are accompanied by increased beta-glucan exposure, with consequent increases in Dectin-1-mediated inflammatory responses by macrophages.
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Affiliation(s)
- T M Hohl
- Infectious Diseases Service, Memorial Sloan-Kettering Cancer Center and Immunology Program, Sloan-Kettering Institute, New York 10021, USA.
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Hohl TM. Stage-specific innate immune recognition of Aspergillus fumigatus and modulation by echinocandin drugs. Med Mycol 2008; 47 Suppl 1:S192-8. [PMID: 18608931 DOI: 10.1080/13693780802078131] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The pulmonary innate immune system clears inhaled Aspergillus fumigatus conidia (spores) from terminal airways. Failure to control conidial germination in immune compromised hosts can result in hyphal tissue invasion and fatal disease. Insight into the molecular recognition of A. fumigatus by host leukocytes indicates that the innate immune system exploits obligate changes in fungal cell wall composition that occur at the first stage of germination, conidial swelling. Germinating spores activate at least two host signal transduction pathways. Surface exposure of fungal beta-(1,3) glucan, a polysaccharide constituent of the fungal cell wall, triggers dectin-1 signaling by host phagocytes. Spore germination leads to the induction of Toll-like receptor (TLR) signaling as well. This stage-specific recognition mechanism focuses host antifungal responses on cells with the potential for tissue invasion and may serve to limit potentially deleterious effects of inflammation in space and time. Fungal beta-(1,3) glucan not only activates host innate immune responses but also represents the target of echinocandin drugs. The activity of echinocandin drugs has largely been understood on the basis of pharmacologic growth inhibition of yeast and moulds, resulting in lysis of yeast cells and stunting of dysmorphic hyphae. The recognition that fungal beta-1,3 glucan activates dectin-1 signaling suggests that echinocandin drugs may exert immune modulatory effects by altering innate immune responses to drug-treated fungal cells, a view supported by recent data from studies on C. albicans, A. fumigatus, and non-Aspergillus moulds.
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Affiliation(s)
- Tobias M Hohl
- Infectious Disease Service, Memorial Sloan-Kettering Cancer Center, New York, USA
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Rocha EMF, Garcia-Effron G, Park S, Perlin DS. A Ser678Pro substitution in Fks1p confers resistance to echinocandin drugs in Aspergillus fumigatus. Antimicrob Agents Chemother 2007; 51:4174-6. [PMID: 17724146 PMCID: PMC2151465 DOI: 10.1128/aac.00917-07] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
An S678P substitution in Fks1p, the major subunit of glucan synthase, was sufficient to confer echinocandin resistance in Aspergillus fumigatus. The equivalent mutation in Candida spp. has been implicated in echinocandin resistance. This work demonstrates that modification of Fks1p is a conserved mechanism for echinocandin resistance in pathogenic fungi.
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Affiliation(s)
- Eleusa Maria F Rocha
- Department of Microbiology and Molecular Genetics, UMDNJ-New Jersey Medical School, Newark, NJ 07103, USA
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