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Lopes L.C.L.,Yeshiva University | Lopes L.C.L.,Federal University of Rio de Janeiro | Guimaraes A.J.,Yeshiva University | De Cerqueira M.D.,Yeshiva University | And 3 more authors.
Clinical and Vaccine Immunology | Year: 2010

Monoclonal antibodies to Histoplasma capsulatum can modify pathogenesis. We now show that monoclonal antibody H1C to a 70-kDa antigen increases intracellular fungal growth and reduces macrophage nitric oxide release but has no effect on fungal burden or survival in murine infection. This further demonstrates the complexities of host-pathogen interactions. Copyright © 2010, American Society for Microbiology. All Rights Reserved.

Uran M.E.,Medical and Experimental Mycology Unit | Uran M.E.,Pontifical Bolivarian University | Nosanchuk J.D.,Yeshiva University | Restrepo A.,Medical and Experimental Mycology Unit | And 5 more authors.
Clinical and Vaccine Immunology | Year: 2011

Several cell wall constituents, including melanins or melanin-like compounds, have been implicated in the pathogenesis of a wide variety of microbial diseases caused by diverse species of pathogenic bacteria, fungi, and helminthes. Among these microorganisms, the dimorphic fungal pathogen Paracoccidioides brasiliensis produces melanin in its conidial and yeast forms. In the present study, melanin particles from P. brasiliensis were injected into BALB/c mice in order to produce monoclonal antibodies (MAbs). We identified five immunoglobulin G1 (IgG1) κ-chain and four IgM melanin-binding MAbs. The five IgG1 κ-chain isotypes are the first melanin-binding IgG MAbs ever reported. The nine MAbs labeled P. brasiliensis conidia and yeast cells both in vitro and in pulmonary tissues. The MAbs cross-reacted with melanin-like purified particles from other fungi and also with commercial melanins, such as synthetic and Sepia officinalis melanin. Melanization during paracoccidioidomycosis (PCM) was also further supported by the detection of IgG antibodies reactive to melanin from P. brasiliensis conidia and yeast in sera and bronchoalveolar lavage fluids from P. brasiliensis-infected mice, as well as in sera from human patients with PCM. Serum specimens from patients with other mycoses were also tested for melanin-binding antibodies by enzyme-linked immunosorbent assay, and cross-reactivities were detected for melanin particles from different fungal sources. These results suggest that melanin from P. brasiliensis is an immunologically active fungal structure that activates a strong IgG humoral response in humans and mice. Copyright © 2011, American Society for Microbiology. All Rights Reserved.

Nucci M.,Federal University of Rio de Janeiro | Queiroz-Telles F.,Federal University of Parana | Tobon A.M.,Medical and Experimental Mycology Unit | Restrepo A.,Medical and Experimental Mycology Unit | Colombo A.L.,University of Sao Paulo
Clinical Infectious Diseases | Year: 2010

This review discusses the epidemiology of the most clinically relevant opportunistic fungal infections in Latin America, including candidiasis, cryptococcosis, trichosporonosis, aspergillosis, and fusariosis. The epidemiologic features, including incidence, of some of these mycoses are markedly different in Latin America than they are in other parts of the world. The most consistent epidemiologic data are available for candidemia, with a large prospective study in Brazil reporting an incidence that is 3- to 15-fold higher than that reported in studies from North America and Europe. Species distribution also differs: in Latin America, the most common Candida species (other than Candida albicans) causing bloodstream infections are Candida parapsilosis or Candida tropicalis, rather than Candida glabrata. © 2010 by the Infectious Diseases Society of America.

Tamayo D.,Molecular and Cell Biology Unit | Tamayo D.,Major College of Antioquia | Hernandez O.,Molecular and Cell Biology Unit | Hernandez O.,Major College of Antioquia | And 4 more authors.
Memorias do Instituto Oswaldo Cruz | Year: 2013

The infectious process starts with an initial contact between pathogen and host. We have previously demonstrated that Paracoccidioides brasiliensis conidia interact with plasma proteins including fibrinogen, which is considered the major component of the coagulation system. In this study, we evaluated the in vitro capacity of P. brasiliensis conidia to aggregate with plasma proteins and compounds involved in the coagulation system. We assessed the aggregation of P. brasiliensis conidia after incubation with human serum or plasma in the presence or absence of anticoagulants, extracellular matrix (ECM) proteins, metabolic and protein inhibitors, monosaccharides and other compounds. Additionally, prothrombin and partial thromboplastin times were determined after the interaction of P. brasiliensis conidia with human plasma. ECM proteins, monosaccharides and human plasma significantly induced P. brasiliensis conidial aggregation; however, anticoagulants and metabolic and protein inhibitors diminished the aggregation process. The extrinsic coagulation pathway was not affected by the interaction between P. brasiliensis conidia and plasma proteins, while the intrinsic pathway was markedly altered. These results indicate that P. brasili-ensis conidia interact with proteins involved in the coagulation system. This interaction may play an important role in the initial inflammatory response, as well as fungal disease progression caused by P. brasiliensis dissemination.

Zuluaga A.,Medical and Experimental Mycology Unit | Ospina-Medina J.,University of Antioquia | Castano-Gallego I.,University of Antioquia | Arango K.,Medical and Experimental Mycology Unit | Gonzalez A.,University of Antioquia
Diagnostic Microbiology and Infectious Disease | Year: 2015

Fungal rhinosinusitis (FRS) is one of the most important rhinosinusoidal disorders, which involves a variety of etiological agents. We carried out a study to determine the frequency of fungal agents in sinus samples from patients with clinically suspected rhinosinusitis (RS). A total of 205 clinical samples were assessed from 174 patients with clinically suspected RS, of which 48 were positive for microscopic examination and culture, 47 were positive for direct examination but negative by culture, 4 were negative for direct examination but positive by culture, and 106 were negative for both methodologies. The main fungal agents isolated were Aspergillus spp. (32.7%), followed by Schizophyllum commune (28.8%). Sensitivity and specificity of the direct examination were 92.3% and 69.3%, respectively, and concordance between the direct examination and culture was 48.4%. This study indicated that both Aspergillus and S. commune appear to be the most important agents involved in the development of FRS. © 2015 Elsevier Inc.

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