Navegando por Palavras-chave "Virulence factor"
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- ItemSomente MetadadadosDiarrheagenic Escherichia coli(Soc Brasileira Microbiologia, 2016) Gomes, Tania Aparecida Tardelli [UNIFESP]; Elias, Waldir P.; Scaletsky, Isabel Cristina Affonso [UNIFESP]; Guth, Beatriz Ernestina Cabilio [UNIFESP]; Rodrigues, Juliana F.; Piazza, Roxane M. F.; Ferreira, Luis C. S.; Martinez, Marina B.Escherichia coli strains live harmlessly in the intestines and rarely cause disease in healthy individuals. Nonetheless, a number of pathogenic strains can cause diarrhea or extraintestinal diseases both in healthy and immunocompromised individuals. Diarrheal illnesses are a severe public health problem and a major cause of morbidity and mortality in infants and young children, especially in developing countries. E. coli strains that cause diarrhea have evolved by acquiring, through horizontal gene transfer, a particular set of characteristics that have successfully persisted in the host. According to the group of virulence determinants acquired, specific combinations were formed determining the currently known E. coli pathotypes, which are collectively known as diarrheagenic E. coli. In this review, we have gathered information on current definitions, serotypes, lineages, virulence mechanisms, epidemiology, and diagnosis of the major diarrheagenic E. coli pathotypes. (C) 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. This isan open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
- ItemAcesso aberto (Open Access)Participação das vesículas extracelulares de leveduras de Sporothrix brasiliensis na resposta imune da Esporotricose: estudo ex vivo e in vivo(Universidade Federal de São Paulo, 2018-02-19) Ikeda, Marcelo Augusto Kazuo [UNIFESP]; Ferreira, Karen Spadari [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Sporotrichosis is a mycotic emerging infectious disease, it affects the skin, lymphatic system, and other organs from humans and animals. The fungus infection has a worldwide distribution and is endemic in areas from Brazil. The disease is caused by the complex of at least four pathogenic species, including Sporothrix brasiliensis. Some fungi release extracelullar vesicles (EVs) to transport molecules, that can interact with the host cell and modulate the immune response. The aim of the study is analyze the participation of the EVs from S. brasiliensis yeasts in the immune response of dendritic cells (DCs) and in murine model. EVs were obtained by differential centrifugation from the supernatant of S. brasiliensis yeast culture. Bone marrow derived DCs were stimulated for 30 minutes with the EVs and then cocultured with yeasts. After 4 hours we analyzed the phagocytic index and after 24 hours the fungal burden. Also, we inoculated the EVs in BALB/c mice before an subcutaneous infection with the fungi, and observed the diameter and fungal burden from the lesion after 21, 35 and 42 days. Our results showed that how much more EVs in the culture higher is the phagocytic index in DCs after 4 hours. However, we observed an increase of the fungal burden after 24 hours of infection. In the murine model, the inoculation of the EVs increased the fungal burden and the diameter of the lesion after 21 days. However, after 35 days, we observed a regression of the lesion, that persists until 42 days after infection. Also, an 100 kD component from EVs reacts with serum from infected animals, and when we analyzed the characterized proteins, we observed some proteins that could be involved in virulence, as WD40 protein, heat shock protein, major facilitator superfamily transporter, extracellular cell wall glucanase, carbonic anhydrase and a mitogen activated protein kinase. These results suggest that EVs can have an important role in virulence and modulation of experimental S. brasiliensis infection.
- ItemSomente MetadadadosPatients with Chronic-form Paracoccidioidomycosis Present High Serum Levels of IgE Anti-paracoccidioides brasiliensis Gp70(Springer, 2013-04-01) Rigobello, F. F.; Marquez, A. S.; Lopes, J. D. [UNIFESP]; Nakanishi-Ito, F. A.; Itano, E. N.; State Univ Londrina UEL; Univ Northern Parana UNOPAR; Universidade Federal de São Paulo (UNIFESP)Paracoccidioidomycosis (PCM) is a disease caused by the Paracoccidioides genus, which includes P. brasiliensis and the new phylogenetic species P. lutzii. Resistance to this infection has been correlated with a Th1 pattern of cellular immune response, while susceptibility is correlated to an intense humoral immune response with an increase in IgE levels. Serum levels of IgE and IgG anti-gp70 and anti-exoantigen in chronic PCM were analyzed by enzyme-linked immunosorbent assay. Results showed a higher gp70 concentration in somatic antigen (SA) than in cell-free antigen (CFA) preparation and significantly higher levels of IgE and IgG anti-gp70 in chronic PCM patients' serum (n = 12) than in normal human serum (n = 12) (p < 0.05). Pearson's correlation analysis showed a strong correlation between IgG and IgE anti-gp70 (r = 0.8424). Additionally, IgE purified from a pool of acute and chronic PCM patient's serum was analyzed by immunoblotting. the patients with the acute form of the disease showed strong bands for gp43 and gp70 in SA but only for gp43 in CFA. in patients with the chronic form, solely the gp43 band was observed. in conclusion, we found that SA is a better source of gp70 than CFA is, and chronic PCM patients show high levels of IgE anti-gp70. This finding suggests that the Th2 immune response is potentially induced by gp70 in PCM disease, which calls for further study.