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A chitin-like component on sclerotic cells of Fonsecaea pedrosoi inhibits Dectin-1-mediated murine Th17 development by masking β-glucans. PLoS One 2014; 9:e114113. [PMID: 25490199 PMCID: PMC4260783 DOI: 10.1371/journal.pone.0114113] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2014] [Accepted: 11/03/2014] [Indexed: 02/02/2023] Open
Abstract
Fonsecaea pedrosoi (F. pedrosoi), a major agent of chromoblastomycosis, has been shown to be recognized primarily by C-type lectin receptors (CLRs) in a murine model of chromoblastomycosis. Specifically, the β-glucan receptor, Dectin-1, mediates Th17 development and consequent recruitment of neutrophils, and is evidenced to have the capacity to bind to saprophytic hyphae of F. pedrosoi in vitro. However, when embedded in tissue, most etiological agents of chromoblastomycosis including F. pedrosoi will transform into the sclerotic cells, which are linked to the greatest survival of melanized fungi in tissue. In this study, using immunocompetent and athymic (nu/nu) murine models infected subcutaneously or intraperitoneally with F. pedrosoi, we demonstrated that T lymphocytes play an active role in the resolution of localized footpad infection, and there existed a significantly decreased expression of Th17-defining transcription factor Rorγt and inefficient recruitment of neutrophils in chronically infected spleen where the inoculated mycelium of F. pedrosoi transformed into the sclerotic cells. We also found that Dectin-1-expressing histocytes and neutrophils participated in the enclosure of transformed sclerotic cells in the infectious foci. Furthermore, we induced the formation of sclerotic cells in vitro, and evidenced a significantly decreased binding capacity of human or murine-derived Dectin-1 to the induced sclerotic cells in comparison with the saprophytic mycelial forms. Our analysis of β-glucans-masking components revealed that it is a chitin-like component, but not the mannose moiety on the sclerotic cells, that interferes with the binding of β-glucans by human or murine Dectin-1. Notably, we demonstrated that although Dectin-1 contributed to the development of IL-17A-producing CD3+CD4+ murine splenocytes upon in vitro-stimulation by saprophytic F. pedrosoi, the masking effect of chitin components partly inhibited Dectin-1-mediated Th17 development upon in vitro-stimulation by induced sclerotic cells. Therefore, these findings extend our understanding of the chronicity of chromoblastomycosis.
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Kneipp LF, Magalhães AS, Abi-Chacra ÉA, Souza LOP, Alviano CS, Santos ALS, Meyer-Fernandes JR. Surface phosphatase inRhinocladiella aquaspersa: biochemical properties and its involvement with adhesion. Med Mycol 2012; 50:570-8. [DOI: 10.3109/13693786.2011.653835] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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Xie Z, Feng P, Zhang J, Li X, Sun J, Lu C, Huang H, Xi L. Molecular cloning, characterization and differential expression of Cdc42 in Fonsecaea monophora. Mol Biol Rep 2011; 39:839-44. [PMID: 21573800 DOI: 10.1007/s11033-011-0806-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Accepted: 04/30/2011] [Indexed: 11/28/2022]
Abstract
The cell divisions cycle 42 (Cdc42) gene has been characterized in the fungi, such as Candida albicans, Penicillium marneffei, and Wangiella (Exophiala) dermatitidis, which plays important roles during growth and development. The partial cDNA sequence of Cdc42 of Fonsecaea monophora (F. monophora), designated FmCdc42, was obtained using degenerate primers based on the conserved domain of the other fungi Cdc42. Then the complete cDNA sequence of FmCdc42 was obtained by 5' and 3' RACE. The full-length cDNA is 1,510 bp in size which had an open reading frame (ORF) of 582 bp, encoding 193 amino acid residues. The predicted molecular mass of FmCdc42 is 21.5 kDa with an estimated theoretical isoelectric point of 5.67. The deduced amino acid sequence of FmCdc42 shows 99% identity to that of Wangiella (Exophiala) dermatitidis. 5 exons and 4 introns are identified within the 1,617 bp FmCdc42 genomic DNA sequence of F. monophora. The ORF could be subcloned into the pCDNA6/myc-His B expression vector. The recombinant protein about 27.5 kD infusion protein had high expression level in Vero cells with SDS-PAGE and Western blot analysis. Quantitative real time RT-PCR revealed that FmCdc42 was the highest expression in the sclerotic bodies' stage compared with that in the mycelia and conidia stages, which indicated that the FmCdc42 may be involved in formation of F. monophora sclerotic bodies.
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Affiliation(s)
- Zhi Xie
- Department of Dermatology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 107 West Yanjiang Road, Guangzhou 510120, China
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Collopy-Junior I, Kneipp LF, da Silva FC, Rodrigues ML, Alviano CS, Meyer-Fernandes JR. Characterization of an ecto-ATPase activity in Fonsecaea pedrosoi. Arch Microbiol 2006; 185:355-62. [PMID: 16528535 DOI: 10.1007/s00203-006-0100-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2005] [Revised: 02/16/2006] [Accepted: 02/20/2006] [Indexed: 10/24/2022]
Abstract
In this work, we characterized an ecto-ATPase activity in intact mycelial forms of Fonsecaea pedrosoi, the primary causative agent of chromoblastomycosis. In the presence of 1 mM EDTA, fungal cells hydrolyzed adenosine-5'-triphosphate (ATP) at a rate of 84.6 +/- 11.3 nmol Pi h(-1) mg(-1) mycelial dry weight. The ecto-ATPase activity was increased at about five times (498.3 +/- 27.6 nmol Pi h(-1) mg(-1)) in the presence of 5 mM MgCl2, with values of Vmax and apparent Km for Mg-ATP(2-) corresponding to 541.9 +/- 48.6 nmol Pi h(-1) mg(-1) cellular dry weight and 1.9 +/- 0.2 mM, respectively. The Mg2+-stimulated ecto-ATPase activity was insensitive to inhibitors of intracellular ATPases such as vanadate (P-ATPases), bafilomycin A1(V-ATPases), and oligomycin (F-ATPases). Inhibitors of acid phosphatases (molybdate, vanadate, and fluoride) or alkaline phosphatases (levamizole) had no effect on the ecto-ATPase activity. The surface of the Mg2+ -stimulated ATPase in F. pedrosoi was confirmed by assays in which 4,4'-diisothiocyanostylbene-2,2'-disulfonic acid (DIDS), a membrane impermeant inhibitor, and suramin, an inhibitor of ecto-ATPase and antagonist of P2 purinoreceptors. Based on the differential expression of ecto-ATPases in the different morphological stages of F. pedrosoi, the putative role of this enzyme in fungal biology is discussed.
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Affiliation(s)
- Italo Collopy-Junior
- Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, CCS, Bloco H, Cidade Universitária, Ilha do Fundão, 21541-590, Rio de Janeiro, Brazil
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Nimrichter L, Cerqueira MD, Leitão EA, Miranda K, Nakayasu ES, Almeida SR, Almeida IC, Alviano CS, Barreto-Bergter E, Rodrigues ML. Structure, cellular distribution, antigenicity, and biological functions of Fonsecaea pedrosoi ceramide monohexosides. Infect Immun 2006; 73:7860-8. [PMID: 16299276 PMCID: PMC1307093 DOI: 10.1128/iai.73.12.7860-7868.2005] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Monohexosylceramides (CMHs, or cerebrosides) have been reported as membrane and cell wall constituents of both pathogenic and nonpathogenic fungi, presenting remarkable differences in their ceramide moiety compared to mammalian CMHs. Current evidence suggests that CMHs are involved in fungal differentiation and growth and contribute to host immune response. Here we describe a structural diversity between cerebrosides obtained from different forms of the human pathogen Fonsecaea pedrosoi. The major CMH species produced by conidial forms displayed the same structure previously demonstrated by our group for mycelia, an N-2'-hydroxyhexadecanoyl-1-beta-d-glucopyranosyl-9-methyl-4,8-sphingadienine. However, the major cerebroside species purified from sclerotic cells carries an additional hydroxyl group, bound to its long-chain base. The structural difference between cerebrosides from mycelial and sclerotic cells was apparently not relevant for their antigenicity, since they were both recognized at similar levels by sera from individuals with chromoblastomycosis and a monoclonal antibody to a conserved cerebroside structure. Preincubation of fungal cells with anti-CMH monoclonal antibodies had no effect on the interaction of F. pedrosoi sclerotic cells with murine macrophages. In contrast to what has been described for other fungal species, sclerotic bodies are resistant to the antifungal action of anti-CMH antibodies. Immunofluorescence analysis showed that recognition of sclerotic cells by these antibodies only occurs at cell wall regions in which melanization is not evident. Accordingly, melanin removal with alkali results in an increased reaction of fungal cells with anti-CMH antibodies. Our results indicate that cerebroside expression in F. pedrosoi cells is associated with dimorphism and melanin assembly on the fungal cell wall.
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Affiliation(s)
- Leonardo Nimrichter
- Instituto de Microbiologia Professor Paulo de Góes, Departamento de Microbiologia Geral, Universidade Federal do Rio de Janeiro Cidade Universitária, Rio de Janeiro, RJ, 21941-590, Brazil.
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Nimrichter L, Barreto-Bergter E, Mendonça-Filho RR, Kneipp LF, Mazzi MT, Salve P, Farias SE, Wait R, Alviano CS, Rodrigues ML. A monoclonal antibody to glucosylceramide inhibits the growth of Fonsecaea pedrosoi and enhances the antifungal action of mouse macrophages. Microbes Infect 2004; 6:657-65. [PMID: 15158773 DOI: 10.1016/j.micinf.2004.03.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2004] [Accepted: 03/11/2004] [Indexed: 10/26/2022]
Abstract
Fungal glucosylceramides (GlcCer) are conserved lipid components in a large variety of pathogenic and non-pathogenic fungal species, but their biological functions are still unclear. Recent studies demonstrate that GlcCer are immunologically active components inducing the production of antifungal antibodies. In this work, a major GlcCer was purified and characterized from mycelial forms of Fonsecaea pedrosoi, the most frequent causative agent of chromoblastomycosis. As determined by fast atom bombardment mass spectrometry (FAB-MS) analysis, the purified molecule was identified as the conserved structure N-2'-hydroxyhexadecanoyl-1-beta-D-glucopyranosyl-9-methyl-4,8-sphingadienine. A monoclonal antibody (Mab) against this structure was used in indirect immunofluorescence with the different morphological stages of F. pedrosoi. Only the surface of young dividing cells was recognized by the antibody. Treatment of F. pedrosoi conidia with the Mab against GlcCer resulted in a clear reduction in fungal growth. In addition, the Mab also enhanced phagocytosis and killing of F. pedrosoi by murine cells. These results suggest that, in F. pedrosoi, GlcCer seem to be cell wall components targeted by antifungal antibodies that directly inhibit fungal development and also enhance macrophage function, supporting the use of monoclonal antibodies to GlcCer as potential tools in antifungal immunotherapy.
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Affiliation(s)
- Leonardo Nimrichter
- Departamento de Microbiologia Geral, Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Cidade Universitária, CCS, Bloco I, Ilha do Fundão, 21941-590, Brazil
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Kneipp LF, Palmeira VF, Pinheiro AAS, Alviano CS, Rozental S, Travassos LR, Meyer-Fernandes JR. Phosphatase activity on the cell wall of Fonsecaea pedrosoi. Med Mycol 2004; 41:469-77. [PMID: 14725320 DOI: 10.1080/10683160310001615399] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The activity of a phosphatase was characterized in intact mycelial forms of Fonsecaea pedrosoi, a pathogenic fungus that causes chromoblastomycosis. At pH 5.5, this fungus hydrolyzed p-nitrophenylphosphate (p-NPP) to p-nitrophenol (p-NP) at a rate of 12.78 +/- 0.53 nmol p-NP per h per mg hyphal dry weight. The values of Vmax and apparent Km for p-NPP hydrolyses were measured as 17.89 +/- 0.92 nmol p-NP per h per mg hyphal dry weight and 1.57 +/- 0.26 mmol/l, respectively. This activity was inhibited at increased pH, a finding compatible with an acid phosphatase. The enzymatic activity was strongly inhibited by classical inhibitors of acid phosphatases such as sodium orthovanadate (Ki = 4.23 micromol/l), sodium molybdate (Ki = 7.53 micromol/l) and sodium fluoride (Ki = 126.78 micromol/l) in a dose-dependent manner. Levamizole (1 mmol/l) and sodium tartrate (10 mmol/l), had no effect on the enzyme activity. Cytochemical localization of the acid phosphatase showed electrondense cerium phosphate deposits on the cell wall, as visualized by transmission electron microscopy. Phosphatase activity in F. pedrosoi seems to be associated with parasitism, as sclerotic cells, which are the fungal forms mainly detected in chromoblastomycosis lesions, showed much higher activities than conidia and mycelia did. A strain of F. pedrosoi recently isolated from a human case of chromoblastomycosis also showed increased enzyme activity, suggesting that the expression of surface phosphatases may be stimulated by interaction with the host.
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Affiliation(s)
- L F Kneipp
- Instituto de Microbiologia Prof. Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Alviano DS, Franzen AJ, Travassos LR, Holandino C, Rozental S, Ejzemberg R, Alviano CS, Rodrigues ML. Melanin from Fonsecaea pedrosoi induces production of human antifungal antibodies and enhances the antimicrobial efficacy of phagocytes. Infect Immun 2004; 72:229-37. [PMID: 14688100 PMCID: PMC344007 DOI: 10.1128/iai.72.1.229-237.2004] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Fonsecaea pedrosoi is a fungal pathogen that produces melanin. The functions of melanin and its possible influence in the protective immunological response during infection by F. pedrosoi are not known. In this work, treatment of F. pedrosoi mycelia with proteases and glycosidases followed by a denaturing agent and hot concentrated acid left a black residue. Scanning electron microscopy demonstrated that this processed melanized residue resembled very closely the intact mycelium in shape and size. Melanin particles were also isolated from culture fluids of conidia or sclerotic forms of F. pedrosoi. Secreted melanins were reactive with sera from infected human patients, suggesting that F. pedrosoi synthesizes melanin in vivo. The antibodies against melanin were purified from patients' sera and analyzed by indirect immunofluorescence. They reacted with sclerotic cells from patients' lesions as well as with sclerotic bodies cultivated in vitro, conidia, mycelia, and digested residues. Treatment of F. pedrosoi with purified antibodies against melanin inhibited fungal growth in vitro. The interaction of F. pedrosoi with phagocytes in the presence of melanin resulted in higher levels of fungal internalization and destruction by host cells, which was accompanied by greater degrees of oxidative burst. Taken together, these results indicate that melanin from F. pedrosoi is an immunologically active fungal structure that activates humoral and cellular responses that could help the control of chromoblastomycosis by host defenses.
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Affiliation(s)
- Daniela S Alviano
- Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Alviano DS, Kneipp LF, Lopes AH, Travassos LR, Meyer-Fernandes JR, Rodrigues ML, Alviano CS. Differentiation of Fonsecaea pedrosoi mycelial forms into sclerotic cells is induced by platelet-activating factor. Res Microbiol 2003; 154:689-95. [PMID: 14643407 DOI: 10.1016/j.resmic.2003.09.002] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Platelet-activating factor (PAF) has been shown to induce the differentiation of several cell types. In this work, we evaluated the effects of PAF on the formation of sclerotic cells of Fonsecaea pedrosoi, the major causative agent of chromoblastomycosis. Cell differentiation was evaluated by light and electron microscopy, which showed that treatment of mycelial forms with PAF results in the generation of sclerotic bodies with typical morphological characteristics. Biochemical features of PAF-induced sclerotic cells were also analyzed and compared with those from sclerotic forms induced by propranolol, a previously described differentiating agent of F. pedrosoi. Chemical analyses of lipid and carbohydrate components from PAF- or propranolol-induced sclerotic bodies revealed that palmitic, stearic, oleic and linoleic acids were the major fatty acid components, while glucose, mannose, galactose and rhamnose were detected as the principal sugar constituents in these cells. Surface carbohydrate components of PAF- and propranolol-induced sclerotic cells were also evaluated, by flow cytometry analysis with twelve different lectins. The profile of reactivity of PAF- or propranolol-induced fungal cells with lectins was also very similar. Hydrolysis of the synthetic substrate p-nitrophenylphosphate by fungal cells demonstrated that the addition of PAF or propranolol to the mycelial cultures similarly promotes a significant increase in ecto-phosphatase activity. These results indicate that the differentiation of F. pedrosoi mycelial cells induced by PAF generates authentic sclerotic forms, as confirmed by the analysis of morphological and biochemical attributes. Since PAF is synthesized in normal conditions by the human host, these observations may have a correlation with the differentiation of F. pedrosoi in vivo.
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Affiliation(s)
- Daniela S Alviano
- Instituto de Microbiologia Professor Paulo de Góes, Departamento de Microbiologia Geral, Universidade Federal do Rio de Janeiro, Cidade, Rio de Janeiro, Brazil.
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da Silva JP, Alviano DS, Alviano CS, de Souza W, Travassos LR, Diniz JAP, Rozental S. Comparison of Fonsecaea pedrosoi sclerotic cells obtained in vivo and in vitro: ultrastructure and antigenicity. FEMS IMMUNOLOGY AND MEDICAL MICROBIOLOGY 2002; 33:63-9. [PMID: 11985971 DOI: 10.1111/j.1574-695x.2002.tb00574.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The parasitic form of Fonsecaea pedrosoi from the hyperkeratotic layer of the skin was obtained from four patients with chromoblastomycosis. Primary cultures containing hyphae and conidia were successfully converted into sclerotic cells in the presence of 800 microM propranolol and low pH as described before. The morphology of sclerotic cells of F. pedrosoi obtained in vivo and in vitro was analyzed by light and electron microscopy. Their antigenicity was also compared by immunofluorescence microscopy and ELISA assays, using serum samples from untreated patients infected with F. pedrosoi. Due to the similarity of the sclerotic cells obtained in vivo and in vitro, the latter can be more adequately in studies of host-parasite interactions in chromoblastomycosis.
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Affiliation(s)
- Jorge P da Silva
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Bloco G, CCS, RJ 21949-970, Brazil
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11
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Rodrigues ML, Rozental S, Couceiro JN, Angluster J, Alviano CS, Travassos LR. Identification of N-acetylneuraminic acid and its 9-O-acetylated derivative on the cell surface of Cryptococcus neoformans: influence on fungal phagocytosis. Infect Immun 1997; 65:4937-42. [PMID: 9393779 PMCID: PMC175712 DOI: 10.1128/iai.65.12.4937-4942.1997] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Sialic acids from sialoglycoconjugates present at the cell surface of Cryptococcus neoformans yeast forms were analyzed by high-performance thin-layer chromatography, binding of influenza A and C virus strains, enzymatic treatment, and flow cytofluorimetry with fluorescein isothiocyanate-labeled lectins. C. neoformans yeast forms grown in a chemically defined medium contain N-acetylneuraminic acid and its 9-O-acetylated derivative. A density of 3 x 10(6) residues of sialic acid per cell was found in C. neoformans. Sialic acids in cryptococcal cells are glycosidically linked to galactopyranosyl units as inferred from the increased reactivity of neuraminidase-treated yeasts with peanut agglutinin. N-Acetylneuraminic acids are alpha-2,6 and alpha-2,3 linked, as indicated by using virus strains M1/5 and M1/5 HS8, respectively, as agglutination probes. The alpha-2,6 linkage markedly predominated. These findings were essentially confirmed by the interaction of cryptococcal cells with the lectins Sambucus nigra agglutinin and Maackia amurensis agglutinin. We also investigated whether the sialyl residues present in C. neoformans are involved in the fungal interaction with a cationic solid-phase substrate and with mouse resident macrophages. Adhesion of yeast cells to poly-L-lysine was mediated, in part, by sialic acid residues, since the number of adherent cells was markedly reduced after treatment with bacterial neuraminidase. The enzymatic removal of sialic acids also made C. neoformans yeast cells more susceptible to endocytosis by macrophages. The results show that sialic acids are components of the cryptococcal cell surface that contribute to its negative charge and protect yeast forms against phagocytosis.
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Affiliation(s)
- M L Rodrigues
- Instituto de Microbiologia Professor Paulo de Góes, Universidade Federal do Rio de Janeiro, Brazil
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12
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de A Soares RM, Angluster J, de Souza W, Alviano CS. Carbohydrate and lipid components of hyphae and conidia of human pathogen Fonsecaea pedrosoi. Mycopathologia 1995; 132:71-7. [PMID: 8819829 DOI: 10.1007/bf01103778] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The carbohydrate and lipid components of mycelium and conidia of Fonsecaea pedrosoi (Brumpt) were analysed by paper, thin-layer and gas-chromatography, mass spectrometry and ultraviolet spectroscopy. Glucose, mannose, galactofuranose, rhamnose and glucosamine were polysaccharide components identified in F. pedrosoi. Significant changes in the carbohydrate pattern occurred during the conversion of mycelium into conidia. Rhamnose was predominant in conidia whereas galactose was prominent in mycelium. Palmitic, stearic, oleic, linoleic, and arachidonic acids were the fatty acids identified in the total lipid fraction. Palmitic and oleic acids were major fatty acids. Marked alterations in the fatty acid constituents were observed between the cell types of F. pedrosoi. Arachidonic acid was detected only in conidia and linoleic acid was preferentially identified in mycelium. Differences in the sterol composition was also associated with morphogenesis in F. pedrosoi. Two main sterols, ergosterol and another less polar sterol, not fully characterized, were found in mycelium whereas in conidia only the latter sterol was present.
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Affiliation(s)
- R M de A Soares
- Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Brazil
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Haase G, Sonntag L, van de Peer Y, Uijthof JM, Podbielski A, Melzer-Krick B. Phylogenetic analysis of ten black yeast species using nuclear small subunit rRNA gene sequences. Antonie Van Leeuwenhoek 1995; 68:19-33. [PMID: 8526477 DOI: 10.1007/bf00873289] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The nuclear small subunit rRNA genes of authentic strains of the black yeasts Exophiala dermatitidis, Wangiella dermatitidis, Sarcinomyces phaemuriformis, Capronia mansonii, Nadsoniella nigra var. hesuelica, Phaeoannellomyces elegans, Phaeococcomyces exophialae, Exophiala jeanselmei var. jeanselmei and E. castellanii were amplified by PCR and directly sequenced. A putative secondary structure of the nuclear small subunit rRNA of Exophiala dermatitidis was predicted from the sequence data. Alignment with corresponding sequences from Neurospora crassa and Aureobasidium pullulans was performed and a phylogenetic tree was constructed using the neighbor-joining method. The obtained topology of the tree was confirmed by bootstrap analysis. Based upon this analysis all fungi studied formed a well-supported monophyletic group clustering as a sister group to one group of the Plectomycetes (Trichocomaceae and Onygenales). The analysis confirmed the close relationship postulated between Exophiala dermatitidis, Wangiella dermatitidis and Sarcinomyces phaeomuriformis. This monophyletic clade also contains the telemorph species Capronia mansonii thus confirming the concept of a teleomorph connection of the genus Exophiala to a member of the herpotrichiellaceae. However, Exophiala castellanii did not belong to this clade. Therefore, this species is not the anamorph of Capronia mansonii as it was postulated.
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Affiliation(s)
- G Haase
- Institute for Medical Microbiology, Klinikum RWTH Aachen, Germany
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de Hoog G, Takeo K, Göttlich E, Nishimura K, Miyaji M. A human isolate ofExophiala(Wangiella) dermatitidis forming a catenate synanamorph that links the generaExophialaandCladophialophora. Med Mycol 1995. [DOI: 10.1080/02681219580000681] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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15
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de Hoog GS, Takeo K, Yoshida S, Göttlich E, Nishimura K, Miyaji M. Pleoanamorphic life cycle of Exophiala (Wangiella) dermatitidis. Antonie Van Leeuwenhoek 1994; 65:143-53. [PMID: 7979319 DOI: 10.1007/bf00871755] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The anamorph life cycle of the black yeast Exophiala (Wangiella) dermatitidis is described. The fungus is dimorphic, yeast cells being the prevalent form of propagation. The fungus is strongly hydrophilic, probably completing its anamorph life cycle in submersion. Adaptation to dry conditions is slow. Types of conidiogenesis comprise annellidic, phialidic and sympodial reproduction, in addition to isotropic development. Phialoconidia fail to germinate under the conditions tested, and thus may have a function other than dispersal. Sterile, multicellular bodies resembling a Capronia teleomorph are described.
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Affiliation(s)
- G S de Hoog
- Research Center for Pathogenic Fungi and Microbial Toxicoses, Chiba University, Japan
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16
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Alviano CS, Farbiarz SR, Travassos LR, Angluster J, de Souza W. Effect of environmental factors on Fonsecaea pedrosoi morphogenesis with emphasis on sclerotic cells induced by propranolol. Mycopathologia 1992; 119:17-23. [PMID: 1406903 DOI: 10.1007/bf00492225] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The influence of growth conditions, as well as of propranolol on Fonsecaea pedrosoi morphogenesis was established using the chemically defined media of Czapeck-Dox (CD) and Butterfield (BF). Mycelial growth of F. pedrosoi in both media was obtained at room temperature (25 degrees C) for 14 days, without shaking, whereas conidia formed at 37 degrees C, for 4 days, in shaken cultures and could be isolated free from the mycelium by filtration in gauze. At low pH (2.5-3.0), there appeared sclerotic cells attached to normal hyphae. When propranolol ws added to the CD medium moniliform hyphae were observed, whereas this drug in the BF medium induced formation of sclerotic cells. Ultrastructural examination revealed that the propranolol-induced sclerotic cells were very similar to those observed in infected tissues.
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Affiliation(s)
- C S Alviano
- Instituto de Microbiologia, Universidade Federal, Rio de Janeiro, Brasil
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Farbiarz S, De Carvalho T, Alviano C, De Souza W. Fine structure and cytochemistry of the interaction betweenFonsecaea pedrosoiand mouse resident macrophages. Med Mycol 1990. [DOI: 10.1080/02681219080000481] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Souza ET, Silva-Filho FC, De Souza W, Alviano CS, Angluster J, Travassos LR. Identification of sialic acids on the cell surface of hyphae and conidia of the human pathogen Fonsecaea pedrosoi. JOURNAL OF MEDICAL AND VETERINARY MYCOLOGY : BI-MONTHLY PUBLICATION OF THE INTERNATIONAL SOCIETY FOR HUMAN AND ANIMAL MYCOLOGY 1986; 24:145-54. [PMID: 3723289 DOI: 10.1080/02681218680000211] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Sialic acids were characterized on the cell surface of conidia and hyphae of Fonsecaea pedrosoi, one of the agents of chromoblastomycosis. Neuraminidase-treated conidia had a reduced negative electrophoretic mobility and, in comparison with untreated cells, bound fewer particles of colloidal iron hydroxide and of cationized ferritin. Sialic acid residues in conidia are linked to galactopyranosyl units as indicated by the increased reactivity of neuraminidase-treated cells with peanut agglutinin. N-acetylneuraminic acid was the only derivative found in the mycelium whereas conidia contained both N-glycolyl- and N-acetylneuraminic acids.
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Abstract
This paper deals mainly with the conidium ontogenesis and phylogenesis of black yeasts such as E. jeanselmei, E. gougerotii, E. dermatitidis and E. spinifera. The conidium ontogenesis of E. jeanselmei, E. gougerotii and E. dermatitidis was almost the same. One to five annellated tips were observed through a scanning microscope at the apices of conidiogenous cells, which were bottle- or jar-shaped. Annellations on the tips looked like fringes and the conidiogenous cells of these three species were annellides. Annellated projections occurred on hyphae and annelloconidia were also produced from them. Occasionally, secondary annellides occurred from primary ones. They looked like moniliform hyphae. Daughter conidia sometimes budded directly from mother cells. The shapes and sizes of the conidia of these species were very similar to each other. The conidium ontogenesis of E. spinifera was annellidic as well. However, a single annellated tip usually occurred on an annellide. The annellated tips of the fungus were long and more than 20 annellations were observed on their walls. The conidiogenesis of the four species of Exophiala is only annellidic. There were no differences in the biological examinations except KNO3 assimilation among these four species. The growth of E. jeanselmei and E. gougerotii was poor at 37 degrees C. The GC contents of E. jeanselmei 1171, E. gougerotii B-1800, E. dermatitidis MM-7 and E. spinifera DU-3342 were 54.6, 54.6, 56.6 and 59.7%, respectively.
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Abstract
A variety of diagnostic tests used by many laboratories to identify isolates of Wangiella dermatitidis (= Fonsecaea dermatitidis) were evaluated. Thirteeen isolates of W. dermatitidis were studied with respect to their ability to grow at 25, 37, 40, 45, and 50 degrees C, colonial and micromorphology, gelatin liquefaction, and hydrolysis of casein, xanthine, hypoxanthine, and tyrosine. All 13 isolates showed growth at 25, 37, and 40 degrees C but failed to grow at higher temperatures. The ability of W. dermatitidis to grow at 40 degrees C can be useful in its identification.
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