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1.
An. acad. bras. ciênc ; 89(3): 1671-1681, July-Sept. 2017. tab, graf
Article in English | LILACS | ID: biblio-886765

ABSTRACT

ABSTRACT Fatty acid methyl esters (FAMEs) were obtained from vegetable oils of soybean, corn and sunflower. The current study was focused on evaluating the antifungal activity of FAMEs mainly against Paracoccidioides spp., as well as testing the interaction of these compounds with commercial antifungal drugs and also their antioxidant potential. FAMEs presented small IC50 values (1.86-9.42 μg/mL). All three FAMEs tested showed antifungal activity against isolates of Paracoccidioides spp. with MIC values ranging from 15.6-500 µg/mL. Sunflower FAMEs exhibited antifungal activity that extended also to other genera, with an MIC of 15.6 μg/mL against Candida glabrata and C. krusei and 31.2 μg/mL against C. parapsilosis. FAMEs exhibited a synergetic effect with itraconazole. The antifungal activity of the FAMEs against isolates of Paracoccidioides spp. is likely due to the presence of methyl linoleate, the major compound present in all three FAMEs. The results obtained indicate the potential of FAMEs as sources for antifungal and antioxidant activity.


Subject(s)
Paracoccidioides/drug effects , Picrates/pharmacology , Soybeans/chemistry , Biphenyl Compounds/pharmacology , Plant Oils/pharmacology , Zea mays/chemistry , Helianthus/chemistry , Antifungal Agents/pharmacology , Picrates/isolation & purification , Biphenyl Compounds/isolation & purification , Plant Oils/chemistry , Microbial Sensitivity Tests , Drug Resistance, Fungal , Lethal Dose 50 , Gas Chromatography-Mass Spectrometry , Antifungal Agents/isolation & purification
2.
Mem. Inst. Oswaldo Cruz ; 111(3): 209-217, Mar. 2016. tab, graf
Article in English | LILACS | ID: lil-777369

ABSTRACT

Fungi of the genus Paracoccidioides are responsible for paracoccidioidomycosis. The occurrence of drug toxicity and relapse in this disease justify the development of new antifungal agents. Compounds extracted from fungal extract have showing antifungal activity. Extracts of 78 fungi isolated from rocks of the Atacama Desert were tested in a microdilution assay against Paracoccidioides brasiliensis Pb18. Approximately 18% (5) of the extracts showed minimum inhibitory concentration (MIC) values≤ 125.0 µg/mL. Among these, extract from the fungus UFMGCB 8030 demonstrated the best results, with an MIC of 15.6 µg/mL. This isolate was identified as Aspergillus felis (by macro and micromorphologies, and internal transcribed spacer, β-tubulin, and ribosomal polymerase II gene analyses) and was grown in five different culture media and extracted with various solvents to optimise its antifungal activity. Potato dextrose agar culture and dichloromethane extraction resulted in an MIC of 1.9 µg/mL against P. brasiliensis and did not show cytotoxicity at the concentrations tested in normal mammalian cell (Vero). This extract was subjected to bioassay-guided fractionation using analytical C18RP-high-performance liquid chromatography (HPLC) and an antifungal assay using P. brasiliensis. Analysis of the active fractions by HPLC-high resolution mass spectrometry allowed us to identify the antifungal agents present in the A. felis extracts cytochalasins. These results reveal the potential of A. felis as a producer of bioactive compounds with antifungal activity.


Subject(s)
Animals , Antifungal Agents/pharmacology , Aspergillus/chemistry , Desert Climate , DNA, Fungal/isolation & purification , Paracoccidioides/drug effects , Chlorocebus aethiops , Chromatography, Reverse-Phase , Cell Survival/drug effects , Cytochalasins/analysis , Mass Spectrometry , Methylene Chloride , Microbial Sensitivity Tests , Phylogeny , Sequence Analysis, DNA , Solid Phase Extraction , Vero Cells/drug effects
3.
Invest. clín ; 56(3): 243-264, sep. 2015. ilus
Article in Spanish | LILACS | ID: biblio-841082

ABSTRACT

El método de referencia, microdilución en caldo, recomendado por el Instituto de Estándares Clínicos y de Laboratorios (CLSI), no está disponible para hongos dimórficos, como los del género Paracoccidioides. En este trabajo se evaluó la sensibilidad in vitro del Complejo Paracoccidoides (n=19) frente a los antifúngicos sistémicos: anfotericina B, 5-fluorocitosina, ketoconazol, itraconazol, fluconazol, voriconazol y caspofungina empleando el método de microdilución (Documento M27-A3 y M27-S3), con algunas modificaciones: tiempo de cultivo en medio de Sabouraud dextrosa agar (7-10 días), medio RPMI 1640 suplementado con glucosa al 2%, tiempo de incubación (7, 8 y 18 días). La sensibilidad in vitro fue variable; la mayoría de los aislados de Paracoccidioides fueron sensibles a ketoconazol (73,7%), seguido de voriconazol (68,4%), itraconazol (63,1%), anfotericina B (52,6%), fluconazol (47,4%), 5-fluorocitosina (42,1%) y caspofungina (5%). La resistencia global fue mayor ante caspofungina (94,7%), seguido de 5-fluorocitocina (52,6%) and anfotericina B (47,4%). El 53% de los aislados fue sensible dosis dependiente a fluconazol, 15,7%, itraconazol y 5,3% a 5-fluorocitosina. Anfotericina B, itraconazol y voriconazol fueron los antifúngicos más potentes contra Paracoccidioides spp (CMI: 0,03-1µg/mL). Basándose en estos resultados, se propone tentativamente un protocolo de ensayo de microdilución para las pruebas de sensibilidad de Paracoccidioides spp frente a fármacos antimicóticos. Esta metodología podría ser clínicamente útil para predecir el desarrollo de resistencias, aunque son necesarios más estudios.


Broth microdilution, the reference method recommended by the Clinical Laboratory Standards Institute (CLSI), is not available for use with dimorphic fungi, such as those of the Paracoccidioides genus. In this work, in vitro susceptibility of the Paracoccidioides complex (n=19) to systemic antifungals: amphotericin B, 5-flucytosine, ketoconazole, itraconazole, fluconazole, voriconazole and caspofungin, was evaluated using the microdilution method (Document M27-A3, M27-S3), with some modifications such as: culture time in Sabouraud dextrose agar (7-10 days), RPMI 1640 medium supplemented with 2% glucose and the incubation time (7, 8 and 18 days). The sensitivity in vitro was variable; the majority of Paracoccidioides isolates was susceptible to ketoconazol (73.7%), followed by voriconazole (68.4%), itraconazole (63.1%), amphotericin B (52.6%), fluconazole (47.4%), 5-flucytosine (42.1%) and caspofungin (5%). The overall resistance was mainly to caspofungin (94.7%), followed by 5-flucytosine (52.6%) and amphotericin B (47.4%). Fifty-three percent of the isolates were susceptible-dose dependent to fluconazole followed by itraconazole (15.7%) and 5-fluorocytosine (5.3%). Amphotericin B, itraconazole and voriconazole were the most potent antifungal drugs against Paracoccidioides spp (CMI: 0.03-1µg/mL). Based on these results, we tentatively propose a microdilution assay protocol for susceptibility testing of Paracoccidioides spp to antifungal drugs. This method may be clinically useful to predict resistance, even though further studies are needed.


Subject(s)
Humans , Paracoccidioides/drug effects , Antifungal Agents/pharmacology , Time Factors , Microbial Sensitivity Tests , Drug Resistance, Fungal
4.
Mem. Inst. Oswaldo Cruz ; 108(3): 342-351, maio 2013. tab, graf
Article in English | LILACS | ID: lil-676971

ABSTRACT

Lapachol was chemically modified to obtain its thiosemicarbazone and semicarbazone derivatives. These compounds were tested for antimicrobial activity against several bacteria and fungi by the broth microdilution method. The thiosemicarbazone and semicarbazone derivatives of lapachol exhibited antimicrobial activity against the bacteria Enterococcus faecalis and Staphylococcus aureus with minimal inhibitory concentrations (MICs) of 0.05 and 0.10 µmol/mL, respectively. The thiosemicarbazone and semicarbazone derivatives were also active against the pathogenic yeast Cryptococcus gattii (MICs of 0.10 and 0.20 µmol/mL, respectively). In addition, the lapachol thiosemicarbazone derivative was active against 11 clinical isolates of Paracoccidioides brasiliensis, with MICs ranging from 0.01-0.10 µmol/mL. The lapachol-derived thiosemicarbazone was not cytotoxic to normal cells at the concentrations that were active against fungi and bacteria. We synthesised, for the first time, thiosemicarbazone and semicarbazone derivatives of lapachol. The MICs for the lapachol-derived thiosemicarbazone against S. aureus, E. faecalis, C. gattii and several isolates of P. brasiliensis indicated that this compound has the potential to be developed into novel drugs to treat infections caused these microbes.


Subject(s)
Anti-Bacterial Agents/pharmacology , Antifungal Agents/pharmacology , Naphthoquinones/pharmacology , Semicarbazones/pharmacology , Thiosemicarbazones/pharmacology , Cryptococcus gattii/drug effects , Enterococcus faecalis/drug effects , Microbial Sensitivity Tests , Paracoccidioides/drug effects , Staphylococcus aureus/drug effects
5.
Rev. Soc. Bras. Med. Trop ; 44(6): 777-780, Nov.-Dec. 2011. tab
Article in English | LILACS | ID: lil-611762

ABSTRACT

INTRODUCTION: Fatty acids are abundant in vegetable oils. They are known to have antibacterial and antifungal properties. METHODS: Antifungal susceptibility was evaluated by broth microdilution assay following CLSI (formerly the NCCLS) guidelines against 16 fungal strains of clinical interest. RESULTS: In this work, fatty acid methyl esters (FAME) was able to inhibit 12 clinical strains of the pathogenic fungus Paracoccidioides brasiliensis and were also active in the bioautographic assay against Cladosporium sphaerospermum. CONCLUSIONS: FAME was a more potent antifungal than trimethoprim-sulfamethoxazole against P. brasiliensis under the experimental conditions tested.


INTRODUÇÃO: Os ácidos graxos são abundantes em óleos vegetais. Eles são conhecidos por suas propriedades antibacterianas e antifúngicas. MÉTODOS: A suscetibilidade a antifúngicos foi avaliada pelo ensaio de microdiluição em caldo de acordo com CLSI (anteriormente NCCLS) sobre 16 isolados de interesse clínico. RESULTADOS: Nesse trabalho, os ésteres metílicos de ácidos graxos (FAME) inibiram doze isolados clínicos do fungo patogênico Paracoccidioides brasiliensis, e também foi muito ativo no ensaio de bioautografia sobre o fungo Cladosporium sphaerospermum. CONCLUSÕES: FAME foi um antifúngico mais potente do que sulfametoxazol-trimetoprim contra P. brasiliensis, nas condições utilizadas no presente trabalho.


Subject(s)
Annona/chemistry , Antifungal Agents/pharmacology , Fatty Acids/pharmacology , Methyl Ethers/pharmacology , Paracoccidioides/drug effects , Plant Extracts/pharmacology , Antifungal Agents/isolation & purification , Candida/classification , Candida/drug effects , Cryptococcus gattii/drug effects , Fatty Acids/isolation & purification , Microbial Sensitivity Tests , Methyl Ethers/isolation & purification , Seeds/chemistry
6.
Mem. Inst. Oswaldo Cruz ; 106(6): 735-741, Sept. 2011. ilus, tab
Article in English | LILACS | ID: lil-602058

ABSTRACT

Multinucleated giant cells (MGC) are cells present in characteristic granulomatous inflammation induced by intracellular infectious agents or foreign materials. The present study evaluated the modulatory effect of granulocyte macrophage colony-stimulating factor (GM-CSF) in association with other cytokines such as interferon-gamma (IFN-γ), tumour necrosis factor-alpha, interleukin (IL)-10 or transforming growth factor beta (TGF-β1) on the formation of MGC from human peripheral blood monocytes stimulated with Paracoccidioides brasiliensis antigen (PbAg). The generation of MGC was determined by fusion index (FI) and the fungicidal activity of these cells was evaluated after 4 h of MGC co-cultured with viable yeast cells of P. brasiliensis strain 18 (Pb18). The results showed that monocytes incubated with PbAg and GM-CSF plus IFN-γ had a significantly higher FI than in all the other cultures, while the addition of IL-10 or TGF-β1 had a suppressive effect on MGC generation. Monocytes incubated with both pro and anti-inflammatory cytokines had a higher induction of foreign body-type MGC rather than Langhans-type MGC. MGC stimulated with PbAg and GM-CSF in association with the other cytokines had increased fungicidal activity and the presence of GM-CSF also partially inhibited the suppressive effects of IL-10 and TGF-β1. Together, these results suggest that GM-CSF is a positive modulator of PbAg-stimulated MGC generation and on the fungicidal activity against Pb18.


Subject(s)
Adult , Humans , Middle Aged , Young Adult , Antigens, Fungal/pharmacology , Cytokines/immunology , Giant Cells/drug effects , Granulocyte-Macrophage Colony-Stimulating Factor/pharmacology , Monocytes/immunology , Paracoccidioides/drug effects , Cells, Cultured , Giant Cells/immunology , Paracoccidioides/immunology
7.
Mem. Inst. Oswaldo Cruz ; 104(4): 644-648, July 2009. graf
Article in English | LILACS | ID: lil-523734

ABSTRACT

Paracoccidioides brasiliensis, a thermal dimorphic fungal pathogen, produces a melanin-like pigment in vitro and in vivo. We investigated the involvement of carbohydrates and monoclonal antibody to CD18, on phagocytosis inhibition, involving macrophage receptors and the resistance of melanized fungal cells to chemically generated nitric oxide (NO), reactive oxygen species (ROS), hypochlorite and H2O2. Our results demonstrate that melanized yeast cells were more resistant than nonmelanized yeast cells to chemically generated NO, ROS, hypochlorite and H2O2, in vitro. Phagocytosis of melanized yeast cells was virtually abolished when mannan, N-acetyl glucosamine and anti-CD18 antibody were added together in this system. Intratracheal infection of BALB/c mice, with melanized yeast cells, resulted in higher lung colony forming units, when compared to nonmelanized yeast cells. Therefore, melanin is a virulence factor of P. brasiliensis.


Subject(s)
Animals , Mice , Antifungal Agents/pharmacology , Macrophages/microbiology , Melanins/biosynthesis , Oxidants/pharmacology , Phagocytosis , Paracoccidioides/pathogenicity , Antibodies, Monoclonal/pharmacology , /drug effects , Carbohydrates/pharmacology , Mice, Inbred BALB C , Paracoccidioides/drug effects , Paracoccidioides/metabolism , Virulence Factors/physiology
8.
Rev. Soc. Bras. Med. Trop ; 41(4): 325-329, jul.-ago. 2008. ilus, graf
Article in English | LILACS | ID: lil-494483

ABSTRACT

In this study, we evaluated the profile of anti-Paracoccidioides brasiliensis immunoglobulin isotypes in serum from patients with the acute and chronic forms of paracoccidioidomycosis, using the whole Paracoccidioides brasiliensis antigen and the antigen treated with sodium metaperiodate. All the immunoglobulin isotypes present in the serum from patients with the acute and chronic forms of paracoccidioidomycosis presented higher reactivity towards the whole antigen than to the antigen treated with metaperiodate (P < 0.05). The reactivity of IgG and IgM to the antigen treated with metaperiodate was greater in serum from patients with the acute form of the disease (P < 0.05), while IgA was more reactive in serum from patients with the chronic form (P < 0.05). There was greater reactivity of IgG1 and IgG2 to the whole antigen and the antigen treated with metaperiodate in the serum from patients with paracoccidioidomycosis than there was in serum from patients with other parasitic infections (P < 0.05). Furthermore, IgG1 from patients with the acute form recognized the 19kDa, 27kDa and 31kDa antigens in the western blot test. Thus, the results suggest that modifications to the epitopes of Paracoccidioides brasiliensis antigens may help to improve the immunodiagnosis of paracoccidioidomycosis.


Neste trabalho, foi avaliado o perfil de isotipos de imunoglobulinas anti-Paracoccidioides brasiliensis em soros de pacientes com formas crônica e aguda de paracoccidiodomicoses usando antígeno total e tratado com meta-periodato. Todos os tipos de imunoglobulinas presentes nos soros de pacientes com formas aguda e crônica apresentaram alta reatividade ao antígeno total quando comparado ao tratado com meta-periodato (P < 0,05). Houve maior reatividade de IgG e IgM anti-antígeno tratado com meta-periodato em soros de pacientes com forma aguda da doença (P < 0,05), enquanto IgA foi mais reativa em soros da forma crônica (P < 0,05). Houve maior reatividade de IgG1 e IgG2 com antígeno total e tratado com meta-periodato em soros de pacientes comparados aos com outras parasitoses (P < 0,05). Além disso, IgG1 de pacientes com a forma aguda reconhecem antígenos de 19kDa, 27kDa e 31kDa por western blot. Assim, os resultados sugerem que alterações nos epitopos de antígenos de Paracoccidioides brasiliensis podem auxiliar no aprimoramento do imunodiagnóstico da paracoccidioidomicose.


Subject(s)
Humans , Antibodies, Fungal/immunology , Antigens, Fungal/immunology , Immunoglobulin Isotypes/immunology , Paracoccidioides/immunology , Paracoccidioidomycosis/immunology , Acute Disease , Antibodies, Fungal/blood , Antibodies, Fungal/drug effects , Antigen-Antibody Reactions/drug effects , Antigen-Antibody Reactions/immunology , Antigens, Fungal/blood , Antigens, Fungal/drug effects , Blotting, Western , Case-Control Studies , Chronic Disease , Epitopes/drug effects , Epitopes/immunology , Immunoglobulin Isotypes/blood , Immunoglobulin Isotypes/drug effects , Mitogens/therapeutic use , Paracoccidioides/drug effects , Paracoccidioidomycosis/blood , Paracoccidioidomycosis/drug therapy , Periodic Acid/therapeutic use
9.
Rev. Inst. Med. Trop. Säo Paulo ; 50(3): 169-175, May-June 2008. ilus, graf
Article in English | LILACS | ID: lil-485624

ABSTRACT

In order to determine the role of lysozyme, an antimicrobial peptide belonging to the innate immune system, against the dimorphic fungus Paracoccidioides brasiliensis, co-cultures of the MH-S murine alveolar macrophages cell line with P. brasiliensis conidia were done; assays to evaluate the effect of physiological and inflammatory concentrations of lysozyme directly on the fungus life cycle were also undertaken. We observed that TNF-α-activated macrophages significantly inhibited the conidia to yeast transition (p = 0.0043) and exerted an important fungicidal effect (p = 0.0044), killing 27 percent more fungal propagules in comparison with controls. Nonetheless, after adding a selective inhibitor of lysozyme, the fungicidal effect was reverted. When P. brasiliensis propagules were exposed directly to different concentrations of lysozyme, a dual effect was observed. Physiologic concentrations of the enzyme facilitated the conidia-to-yeast transition process (p < 0.05). On the contrary, inflammatory concentrations impaired the normal temperature-dependant fungal transition (p < 0.0001). When yeast cells were exposed to lysozyme, irrespective of concentration, the multiple-budding ability was badly impaired (p < 0.0001). In addition, ultra-structural changes such as subcellular degradation, fusion of lipid vacuoles, lamellar structures and interruption of the fibrilar layer were observed in lysozyme exposed conidia. These results suggest that lysozyme appears to exert a dual role as part of the anti-P. brasiliensis defense mechanisms.


Com a finalidade de determinar o papel da lisozima, um peptídeo antimicrobiano que pertence ao sistema imune inato, contra o fungo dimórfico Paracoccidioides brasiliensis, foram feitas co-culturas de uma linha de macrófagos alveolares murinos (MH-S) com as conídias do fungo na presença ou não do TNF-α e/ou um inibidor da lisozima; também foram feitos ensaios que avaliaram o efeito das concentrações fisiológicas e inflamatórias de lisozima diretamente sobre o ciclo de vida do fungo. Observamos que os macrófagos ativados com a citoquina tiveram um efeito significativo na inibição da transição conídia/levedura (p = 0,0043) e exerceram um efeito fungicida importante (p = 0,0044), matando mais de 27 por cento das propágulas do fungo em comparação com os macrófagos não ativados. No entanto, após ser o inibidor seletivo da lisozima adicionado, o efeito fungicida foi revertido. Quando os propágulos do fungo foram expostos diretamente a diferentes concentrações da lisozima, um duplo efeito foi observado. Assim, as concentrações fisiológicas da enzima facilitaram o processo de transição conídia-levedura (p < 0,05). Contrariamente, as concentrações inflamatórias prejudicaram a transição fúngica (p < 0,0001). Quando as leveduras foram expostas a qualquer concentração de lisozima, sua capacidade de multi-brotação foi gravemente prejudicada (p < 0,0001). Além disso, mudanças ultra-estruturais, como a sub degradação, a fusão dos vacúolos dos lípidos, estruturas lamelares e interrupção da camada fibrilar foram observadas em conídios expostos à lisozima. Estes resultados sugerem que a lisozima poderia exercer um duplo papel no mecanismo antifúngico contra P. brasiliensis.


Subject(s)
Animals , Humans , Mice , Antifungal Agents/pharmacology , Interferon-alpha/pharmacology , Macrophage Activation/drug effects , Macrophages, Alveolar/microbiology , Muramidase/pharmacology , Paracoccidioides/drug effects , Coculture Techniques/methods , Enzyme Inhibitors/pharmacology , Life Cycle Stages/drug effects , Mice, Inbred BALB C , Macrophage Activation/immunology , Macrophages, Alveolar/drug effects , Paracoccidioides/growth & development , Paracoccidioides/ultrastructure , Time Factors
10.
Rev. Inst. Med. Trop. Säo Paulo ; 49(1): 11-16, Jan.-Feb. 2007. graf
Article in English | LILACS | ID: lil-444571

ABSTRACT

Iron is an essential growth element of virtually all microorganisms and its restriction is one of the mechanisms used by macrophages to control microbial multiplication. Paracoccidioides brasiliensis, the agent of paracoccidioidomycosis, an important systemic mycosis in Latin America, is inhibited in its conidia-to-yeast conversion in the absence of iron. We studied the participation of iron in the nitric oxide (NO)-mediated fungicidal mechanism against conidia. Peritoneal murine macrophages activated with 50U/mL of IFN-gamma or treated with 35 æM Deferoxamine (DEX) and infected with P. brasiliensis conidia, were co-cultured and incubated for 96 h in the presence of different concentrations of holotransferrin (HOLO) and FeS0(4). The supernatants were withdrawn in order to assess NO2 production by the Griess method. The monolayers were fixed, stained and observed microscopically. The percentage of the conidia-to-yeast transition was estimated by counting 200 intracellular propagules. IFN-gamma-activated or DEX-treated Mthetas presented marked inhibition of the conidia-to-yeast conversion (19 and 56 percent, respectively) in comparison with non-activated or untreated Mthetas (80 percent). IFN-gamma-activated macrophages produced high NO levels in comparison with the controls. Additionally, when the activated or treated-macrophages were supplemented with iron donors (HOLO or FeSO4), the inhibitory action was reversed, although NO production remained intact. These results suggest that the NO-mediated fungicidal mechanism exerted by IFN-gamma-activated macrophages against P. brasiliensis conidia, is dependent of an iron interaction.


O ferro é elemento essencial para o crescimento de microrganismos e sua limitação é um dos mecanismos usados por macrófagos para controlar a multiplicação microbiana. Paracoccidioides brasiliensis, o agente da paracoccidioidomicose, uma das micoses sistêmicas mais importantes na América Latina, é inibido em sua conversão de conídia-à-levedura na ausência do ferro. Estudamos a participação do ferro no mecanismo fungicida mediado pelo óxido nítrico (NO) na sua interação com as conídias do fungo. Macrófagos peritoneais murinos ativados com 50U/mL de IFN-gama ou tratados com 35 æM Deferoxamina (DEX) e infectados com conídias do P. brasiliensis foram co-cultivados e incubados por 96 h na presença de concentrações diferentes de holotransferrina (HOLO) e FeS0(4). Os sobrenadantes foram retirados a fim de avaliar a produção de NO2 pelo método de Griess. Os macrófagos eram fixados, corados e observados ao microscópio. A porcentagem da transição de conídia-à-levedura foi estimada contando 200 propágulos intracelulares. Os macrófagos ativados com citocina ou tratados com DEX apresentaram inibição marcada da conversão de conídia-à-levedura (19 e 56 por cento, respectivamente) em comparação com macrófagos controle (80 por cento). Os macrófagos ativados com IFN-gama produziram elevação nos níveis de NO em comparação com macrófagos não-tratados ou não-activados. Adicionalmente, quando as monocapas ativadas ou tratadas foram suplementadas com doadores do ferro (HOLO ou FeSO4), a ação inibitória foi revertida embora a produção de NO permanecesse intacto. Estes resultados sugerem que o mecanismo fungicida mediado pelo NO exercido por macrófagos ativados com IFN-gama contra conídias do P. brasiliensis é dependente de uma interação do ferro.


Subject(s)
Animals , Male , Mice , Deferoxamine/pharmacology , Interferon-gamma/pharmacology , Iron/pharmacology , Macrophages, Peritoneal/microbiology , Nitric Oxide Synthase/drug effects , Paracoccidioides/growth & development , Transferrin/pharmacology , Mice, Inbred BALB C , Macrophage Activation/drug effects , Macrophages, Peritoneal/drug effects , Paracoccidioides/drug effects , Paracoccidioides/immunology
11.
Rev. Inst. Med. Trop. Säo Paulo ; 47(5): 263-266, Sept.-Oct. 2005.
Article in English | LILACS | ID: lil-417084

ABSTRACT

Os mecanismos utilizados pelo Paracoccidioides brasiliensis para sobreviver em células fagocitárias ainda não estão elucidados. O metabolismo celular férrico é muito importante para o crescimento de inúmeros patógenos intracelulares cuja capacidade de se multiplicarem em fagócitos mononucleares é dependente da disponibilidade intracelular do íon ferro. Assim, o objetivo deste trabalho foi investigar o papel do ferro intracelular sobre a capacidade do P. brasiliensis sobreviver em monócitos humanos. O tratamento de monócitos com deferoxamina, uma droga quelante, diminuiu a sobrevivência de leveduras do fungo de forma dose-dependente. O efeito inibidor da deferoxamina sobre a sobrevivência do P. brasiliensis foi revertido por transferrina saturada com ferro (holotransferrina) mas não por transferrina insaturada (apotransferrina). Estes resultados sugerem que a sobrevivência do P. brasiliensis em monócitos humanos é dependente do íon ferro.


Subject(s)
Humans , Apoproteins/pharmacology , Deferoxamine/pharmacology , Monocytes/microbiology , Paracoccidioides/drug effects , Siderophores/pharmacology , Transferrin/pharmacology , Deferoxamine/antagonists & inhibitors , Iron/physiology , Paracoccidioides/physiology , Siderophores/antagonists & inhibitors
12.
Genet. mol. res. (Online) ; 4(2): 430-449, 30 jun. 2005. tab, ilus
Article in English | LILACS | ID: lil-445278

ABSTRACT

The rise in antifungal resistance, observed as a result of the increasing numbers of immunocompromised patients, has made the discovery of new targets for drug therapy imperative. The description of the Paracoccidioides brasiliensis transcriptome has allowed us to find alternatives to refine current therapy against paracoccidioidomycosis. We used comparative analysis of expressed sequence tags to find promising drug targets that have been addressed in other pathogens. We divided the analysis into six different categories, based on the involvement of the targeted mechanisms in the cell: i) cell wall construction, ii) plasma membrane composition, iii) cellular machinery, iv) cellular metabolism, v) signaling pathways, and vi) other essential processes. Through this approach, it has been possible to infer strategies to develop alternative drugs against this pathogen.


Subject(s)
Humans , Antifungal Agents/pharmacology , Drug Design , Expressed Sequence Tags , Paracoccidioides/genetics , Transcription, Genetic/genetics , Paracoccidioides/drug effects , Paracoccidioides/metabolism , Cell Wall/drug effects , Cell Wall/enzymology , Cell Wall/metabolism
13.
Genet. mol. res. (Online) ; 4(2): 390-408, 30 jun. 2005. ilus, tab
Article in English | LILACS | ID: lil-445280

ABSTRACT

In the struggle for life, the capacity of microorganisms to synthesize and secrete toxic compounds (inhibiting competitors) plays an important role in successful survival of these species. This ability must come together with the capability of being unaffected by these same compounds. Several mechanisms are thought to avoid the toxic effects. One of them is toxin extrusion from the intracellular environment to the outside vicinity, using special transmembrane proteins, referred to as transporters. These proteins are also important for other reasons, since most of them are involved in nutrient uptake and cellular excretion. In cancer cells and in pathogens, and particularly in fungi, some of these proteins have been pointed out as responsible for an important phenotype known as multidrug resistance (MDR). In the present study, we tried to identify in the Paracoccidioides brasiliensis transcriptome, transporter-ortholog genes from the two major classes: ATP binding cassette and major facilitator superfamily transporter. We found 22 groups with good similarity with other fungal ATP binding cassette transporters, and four Paracoccidioides brasilienses assembled expressed sequence tags that probably code for major facilitator superfamily proteins. We also focused on fungicide resistance orthologs already characterized in other pathogenic fungi. We were able to find homologs to C. albicans CDR1, CDR2, and MDR1, Saccharomyces cerevisiae PDR5 and Aspergillus AtrF genes, all of them related to azole resistance. As current treatment for paracoccidioidomycosis mainly uses azole derivatives, the presence of these genes can be postulated to play a similar role in P. brasiliensis, warning us for the possibility of resistant isolate emergence.


Subject(s)
Humans , Antifungal Agents/pharmacology , Expressed Sequence Tags/metabolism , Paracoccidioides/drug effects , Drug Resistance, Multiple, Fungal/genetics , Transcription, Genetic , ATP-Binding Cassette Transporters/genetics , Paracoccidioides/genetics , Paracoccidioides/metabolism , Membrane Transport Proteins/drug effects , Membrane Transport Proteins/genetics , Membrane Transport Proteins/physiology , Drug Resistance, Multiple, Fungal/physiology , ATP-Binding Cassette Transporters/drug effects , ATP-Binding Cassette Transporters/metabolism
14.
RBM rev. bras. med ; 56(4): 239-246, abr. 1999. ilus
Article in Portuguese | LILACS | ID: lil-234770

ABSTRACT

A blastomicose sul americana (BSB) e doenca causada pelo fungo Paracoccidioides brasiliensis.Ela acomete principalmente lavradores do sexo masculino, por via inalatoria,acometendo os pulmoes em mais de 80 por cento dos casos na forma cronica do adulto.Foram estudados 30 pacientes com DSA durante tes anos com radiogramas de torax e tomografia computadorizada de torax de alta resolucao(TCTAR) para correlacionar seus achados no sentido de auxiliar o diagnostico.O radiograma confirmou os achados mais comuns:infiltrados reticular e nodular,mais nos campos medios,alguns com consolidacao(19=63 por cento)hiperinsuflacao(20=66 pr cento)e bolhas subpleurais(10=33por cento).A TCTAR mostrou a historia natural da doenca: 1. Via inalatoria:com multiplas areas parenquimatosas semelhates a vidro fosco que podem progredir ou regredir(3=10 por cento) 2. Lesoes parenquimatosas progressivas com nodulos(25=83,3 por cento) consolidacoes irregulares(20=66 por cento, as vezes com insuflacao(22=73 por cento e bronquiectasias de tracao( 4=13 por cento)cavitacoes podem ocorrer por necrose(9=30 por cento) 3.Via linfatica com espessamento intersticial axial na zona medular com distorcao(25=83,3 por cento)4.Doenca progressiva com componente fibrotico e insuflacao(4=13 por cento).Conclusoes:As lesoes podem predominar em uma das duas regioes pulmonares.Temos:a padrao predominando lesoes parenquimatosas;padra predominando lesoes interticiais axiais;padrao predominando lesoes escavadas;e padrao combinado das lesoes


Subject(s)
Humans , Male , Paracoccidioides/classification , Paracoccidioides/drug effects , Paracoccidioides/physiology , Tomography/statistics & numerical data
15.
Säo Paulo; s.n; 1999. 105 p. ilus.
Thesis in Portuguese | LILACS | ID: lil-272492

ABSTRACT

Diversos trabalhos têm demonstrado variabilidade biológica em Paracoccidioides brasiliensís. As múltiplas manifestações clínicas da PCM e a depressão da resposta imune celular, especialmente do tipo 1, que é recuperada após terapêutica efetiva, são indicativos de que os processos de infecção e evolução da doença dependem também de fatores relacionados à virulência do agente. Com o objetivo de investigar possíveis mercadores que pudessem estar associados ao papel do agente na determinação da forma clínica da PCM foi proposto um estudo de algumas características microbiológicas comparando-se 30 isolados de P. brasilíensís. O primeiro grupo "A', foi constituído por 15 cultivos obtidos de pacientes que desenvolveram a forma aguda da doença. O grupo "C" representou os isolados de pacientes com PCM forma crônica. Os fungos, recebidos de várias procedências, eram mantidos em laboratório por períodos variáveis. A fim de recuperar o potencial de virulência, supostamente atenuado durante os subcultivos ín vitro, todos os fungos foram inicialmente reisolados após desenvolvimento de orquite em hamsters. O estudo foi basicamente desenvolvido com a forma leveduriforme do fungo, obtida por cultivos em PYGA, a 35º C. Os parâmetros incluíram: morfologia microscópica (morfometria da célula-mãe e número de brotamentos)- velocidade de transformação in vitro da forma miceliana para a forma leveduriforme; determinação de curvas de crescimento; expressão da glicoproteína de 43KDa (gp43); polimorfismo isoenzimático e determinação do perfil de susceptibilidade, ín vitro, dos isolados frente aos antifúngicos empregados na terapêutica da PCM. Em todos os aspectos analisados ficou evidente a expressiva variabilidade biológica entre os isolados. Foi possível padronizar o teste de susceptibilidade aos antifúngicos através de adaptações à técnica de referência proposta pelo NCCLS, (l997). Os resultados mostraram-se seguros e reprodutíveis desde que se utilizem cultivos com alto grau de viabilidade celular. Foram testadas anfotericina B, 5-fluorocitosina e os azólicos ítraconazol, cetoconazol e fluconazol. Frente à 5-fiuorocitosina, todos os isolados foram resistentes a concentraçäo iguais ou superiores a 64mg/mL da droga. Em relação aos demais antifúngicos, houve variabilidade nos títulos das ClMs não se caracterizando, porém, nenhum caso de resistência microbiana in vitro. As curvas de crescimento, determinadas através de ...(au)


Subject(s)
Paracoccidioides/drug effects , Paracoccidioides/enzymology , Paracoccidioides/physiology , Paracoccidioidomycosis/microbiology
16.
Rev. argent. micol ; 20(1/3): 46-52, 1997. ilus, tab
Article in Spanish | LILACS | ID: lil-216239

ABSTRACT

De acuerdo a investigaciones previas realizadas con solución sobresaturada de azúcar, hemos comprobado su acción fungicida, la cual había sido probada satisfactoriamente sobre bacterias por la Dra. Joseph, A. y cols. A la solución sobresaturada de azúcar se incorporó eugenol, con el objeto de acelerar la muerte de las cepas fúngicas ensayadas. Se observaron diferencias significativas en el tiempo de muerte de los hongos estudiados con respecto a los ensayos anteriores con solución sobresaturada de azúcar


Subject(s)
Food Contamination/analysis , Eugenol/therapeutic use , Food Microbiology , Fungi/drug effects , In Vitro Techniques , Sucrose/therapeutic use , Antifungal Agents , Candida albicans/drug effects , Cladosporium/drug effects , Microsporum/drug effects , Paracoccidioides/drug effects , Penicillium/drug effects , Sucrose/pharmacology , Trichophyton/drug effects
19.
An. bras. dermatol ; 67(5): 251-4, set.-out. 1992. tab
Article in Portuguese | LILACS | ID: lil-123485

ABSTRACT

Säo analisados retrospectivamente 500 protocolos clínicos de pacientes com paracoccidioidomicose do Hospital Evandro Chagas, Fundaçäo Oswaldo Cruz, Rio de Janeiro observados no período de 1960 a 1986. A amostra estudada consta de 466 homens e 34 mulheres, com idades que variaram de quatro a 83 anos, tendo predominado a doença ema dultos masculinos, entre 30 e 60 anos, que exerciam ou exerceram atividades na lavoura. Os órgäos mais atingidos foram mucosa, pulmöes e linfonodos. Quanto à forma clínica, 465 casos do tipo adulto e 35 do juvenil, sendo neste tipo o sexo feminino proporcionalmente mais atingido


Subject(s)
Humans , Male , Female , Adult , Aged , Clinical Laboratory Techniques/trends , Blood Protein Electrophoresis/methods , Paracoccidioides/drug effects , Paracoccidioidomycosis/epidemiology , Rural Workers , Brazil , Intestinal Mucosa/pathology , Mucoproteins/therapeutic use , Lung/pathology
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