Navegando por Palavras-chave "enteropathogenic Escherichia coli"
Agora exibindo 1 - 8 de 8
Resultados por página
Opções de Ordenação
- ItemSomente MetadadadosAcute diarrhea and malnutrition: Lethality risk in hospitalized infants(Amer Coll Nutrition, 1999-08-01) Fagundes-Neto, Ulysses [UNIFESP]; Andrade, Jacy Alves Braga de [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Objectives: Acute diarrhea is a very frequent disease in developing countries and is the first cause of death in infants under two years of age. This study was designed to evaluate the clinical and epidemiological factors associated to the death of 17 out of 511 infants hospitalized due to severe acute diarrhea between January 1989 and December 1995.Patients and Methods: The patients were divided into two groups according to their clinical evolution: Group I-Death and Group II-Survival. The following parameters were evaluated: birth weight, gender, age, duration of diarrhea (days) prior to admission, nutritional status, hydration, presence of an enteropathogenic agent in the stools, food intolerance and duration of hospitalization.Results: The analyzed factors have shown a significant association with death for the following variables: age, relative factor of death (RFD)=4.0 for infants less than six months of age, identification of an enteropathogenic Escherichia coli (EPEC) strain in the stools (RFD=3.3), severe malnutrition at admission to the hospital (RFD=4.5), occurrence of food intolerance during hospitalization (RFD=2.7). Some enteropathogenic agent was identified in the stools of 253 infants (54.9%), among the 461 (90.2%) studied. Group I revealed the presence of an enteropathogenic agent in 75% of the cases. The most frequent agents identified in Group I were: EPEC (56.3%) and Shigella (12.5%), while in Group II EPEC was identified in 26.5% of the patients.Conclusions: The association of some factors, such as age less than six months, severe malnutrition, food intolerance and the identification of EPEC strains in the stool culture, indicate a high risk of death in infants hospitalized due to severe acute diarrhea.
- ItemAcesso aberto (Open Access)Genetic analysis of Escherichia coli strains carrying enteropathogenic Escherichia coli (EPEC) markers, isolated from children in Rio de Janeiro city, Brazil(Sociedade Brasileira de Microbiologia, 2003-11-01) Regua-Mangia, Adriana Hamond; Gomes, Tania Aparecida Tardelli [UNIFESP]; Andrade, João Ramos da Costa; Vieira, Mônica Aparecida Midolli [UNIFESP]; Gonzalez, Alice Gonçalves Martins; Zahner, Viviane; Irino, Kinue; Teixeira, Lúcia Martins; Fundação Oswaldo Cruz; Universidade Federal de São Paulo (UNIFESP); Universidade Estadual do Rio de Janeiro; Universidade Federal Fluminense; Instituto Adolfo Lutz; Universidade Federal do Rio de JaneiroIn the present study, 47 enteropathogenic Escherichia coli strains identified according to serotyping, presence of eae, bfp and EAF sequences, adherence phenotype and ability to induce attaching-effacing lesions were analyzed by pulsed-field gel electrophoresis (PFGE), multilocus enzyme electrophoresis (MLEE), and the presence of LEE genes (eae, espA, espB, tir) as well as the respective alleles. Amplification of LEE genes subtypes revealed 18 different pathotypes. Typing of the eae gene showed that most strains contained nontypable intimin (42%) followed by beta (35%), gamma and alpha genes (12% each). PFGE analysis revealed a variable degree of polymorphism among isolates and, in general, no clear correlation was observed among PFGE profiles and the virulence markers identified. Otherwise, grouping based on MLEE analysis showed a close association between eae allele and clonal cluster distribution leading us to indicate the eae profile as a promising marker to establish relatedness among such microorganisms.
- ItemSomente MetadadadosInjury switches melatonin production source from endocrine (pineal) to paracrine (phagocytes) - melatonin in human colostrum and colostrum phagocytes(Blackwell Publishing, 2006-09-01) Pontes, Gerlandia N.; Cardoso, Elaine C.; Carneiro-Sampaio, Magda M. S.; Markus, Regina P.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)A large number of data show that melatonin has immunomodulatory properties and is produced by immunocompetent cells; also, some evidence suggests a 'feedback' of the activated immune system on the pineal gland. in this paper, we studied immune-pineal interactions in colostrum obtained from healthy puerperae and mothers with mastitis taking into account that, (a) melatonin levels in milk reflects pineal activity and (b) colostrum quiescent mononuclear and polymorphonuclear phagocytes from healthy mothers in culture are adequate for evaluating the ability of immunocompetent cells to produce melatonin. Here we compared the diurnal and nocturnal melatonin levels in colostrum from healthy puerperae and mothers with mastitis; this is a unique noninvasive model for determining pineal activity in the proinflammatory phase of a defense response. in addition, we determined the 'in vitro' production of melatonin by colostrum immunocompetent cells stimulated by enteropathogenic Escherichia coli or zymosan. Suppression of nocturnal melatonin rise in mothers with mastitis was highly correlated with increased tumor necrosis factor-alpha (TNF-alpha) secretion. This result, interpreted taking into account the presence of the transcription factor nuclear factor kappa B in pineal gland, suggest that the proinflammatory cytokine can inhibit nocturnal pineal melatonin production. On the other hand, stimulated, but not quiescent, immunocompetent cells secreted in the colostrum produced melatonin in vitro. in addition, this production ceases after bacteria killing. These results suggest that during the response to an injury the production of melatonin can be transiently shifted from an endocrine (pineal) to a paracrine (immunocompetent cells) source.
- ItemSomente MetadadadosMetabolism of phenylpropionic acid in enteropathogenic Escherichia coli belonging to serogroup O111 and its application for diagnosis(Elsevier B.V., 2001-10-16) Irino, Kinue; Dias, Angela Maria G; Kano, Elena; Vaz, Tania MI; Kato, Maria AMF; Goncalces, Celia R.; Vieira, Monica AM [UNIFESP]; Gomes, Tania Aparecida Tardelli [UNIFESP]; Inst Adolfo Lutz Registro; Universidade Federal de São Paulo (UNIFESP)We evaluated a biochemical assay based on the ability to metabolise beta -phenylpropionic acid (PPA) as a diagnostic aid in the identification of typical enteropathogenic Escherichia coli (EPEC) strains. A total of 1061 E. coli strains of serogroups O55, O111, and O119 were initially characterised regarding their H types (serotypes) and the presence of EPEC DNA sequences, eae, EAF, and bfpA. in case of the serogroup O111 strains, 84.6% carried the typical EPEC markers, and the great majority of those (98.1%) were PPA-positive. in contrast, only 0.9% of the serogroups O55 and O119 strains carrying the typical EPEC markers (53.6% and 75.4%, respectively) were PPA-positive. We conclude that the PPA test is a useful method to detect typical EPEC strains only among strains of the O111 serogroup. (C) 2001 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
- ItemSomente MetadadadosMorphometric study of the small bowel mucosa in infants with diarrhea due to enteropathogenic Escherichia coli strains(H G E Update Medical Publ Ltd., 1997-07-01) Fagundes Neto, Ulysses [UNIFESP]; Kallas, Marcia Rached Esper [UNIFESP]; Patricio, Francy Reis da Silva [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Background/Aims: Enteropathogenic Escherichia coli (EPEC) strains are the most important cause of gastroenteritis in. infants under 1 year of age and may induce several patterns of villous atrophy in the intestinal mucosa. However, the interpretation of these abnormalities has usually been based on semiquantitative criteria, giving rise to considerably subjective results. We utilized the linear morphometry to analyze the morphological lesions of the small bowel mucosa induced by EPEC strains in infants with persistent diarrhea in comparison with those seen, in infants with asymptomatic environmental enteropathy (AEE) and controls.Methodology: Fifty nine specimens of smalt bowel mucosa were comparatively studied and divided in the following groups: 1- Group I: Thirty infants with persistent diarrhea due to EPEC strains, mean age 6.4 months; 2- Group II: Sixteen infants with AEE, mean. age 6.5 months with no enteropathogenic bacteria in stools; 3- Group III: Thirteen children with short stature and no gastrointestinal complaints, mean age 15 months. Morphometric analysis of the small bowel mucosa was performed by using a x10 objective to a Zeiss light microscope, to which a measuring Zeiss ocular, t8x was adapted. The following measurements were carried out: Total mucosal thickness (TMT); Villous height (VH); Crypt length (CL) Intraepithelial lymphocyte (IEL) count.Results: Except for the IEL, there was a significant difference in all the parameters analyzed among the evaluated groups. Group I revealed the lowest values for total mucosal thickness, villous height, and the ratio villous height/crypt length in comparison with the two other groups. On the other hand, the crypt length measurements for Group II were larger than those for Groups I and III. The measurements of villous height and the ratio villous height/crypt length for Group III turned out to be greater than those for Group II.Conclusions: The utilization of an accurate technique in the morphological study of the small bowel mucosa allowed us to detect severe abnormalities not only in. infants with EPEC infection, but also in those counterparts who live in contaminated environments, and can therefore potentially acquire this type of intestinal infection.
- ItemSomente MetadadadosNutritional impact and ultrastructural intestinal alterations in severe infections due to enteropathogenic Escherichia coli strains in infants(Amer Coll Nutrition, 1996-04-01) Fagundes Neto, Ulysses [UNIFESP]; Freymüller-Haapalainen, Edna [UNIFESP]; Schimitz, Lenora Gandolfi [UNIFESP]; Scaletsky, Isabel Cristina Affonso [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Objective: Enteropathogenic Escherichia coli (EPEC) strains are able to adhere to human intestinal tissue inducing a typical lesion causing dissolution of the brush border membrane and loss of microvillus structure at sites of bacterial attachment. The presence of these lesions can provoke perpetuation of diarrhea associated with malabsorption of the nutrients and nutritional aggravation. In this paper we report the nutritional impact of severe EPEC gastroenteritis in infants in a small bowel ultrastructural study.Methods and Results: Two infants aged 3 months and one 4 month old infant with profuse watery diarrhea lasting less than 6 days were studied. After rehydration therapy, the patients were fed a cow's milk formula and since food intolerance was diagnosed, a protein-hydrolisate, lactose-free formula was introduced. This dietary modification was successful, diarrhea ceased, the patients were discharged and followed up for 30 days. The following EPEC strains were identified in the stools and in the jejunal secretion: O111ab:H2, O119:H6 and O18ab:H14. A small bowel biopsy was performed and the electron microscopic study revealed bacteria tightly adhered to the apical portion of the enterocyte and effacement of the microvilli. These lesions were more prominent in the areas where bacteria were present.Conclusion: The patients underwent an acute nutritional aggravation due to food intolerance, but the introduction of a protein-hydrolisate, lactose-free formula, allowed prompt cessation of diarrhea and nutritional recovery.
- ItemAcesso aberto (Open Access)Production of cytolethal distending toxin and other virulence characteristics of Escherichia coli strains of serogroup O86(Instituto Oswaldo Cruz, Ministério da Saúde, 2001-07-01) Ghilardi, Ângela Cristina Rodrigues; Gomes, Tania Aparecida Tardelli [UNIFESP]; Trabulsi, Luiz Rachid; Instituto Adolfo Lutz Seção de Bacteriologia; Universidade Federal de São Paulo (UNIFESP); Instituto Butantã Laboratório Especial de MicrobiologiaGenetic and phenotypic virulence markers of different categories of diarrhoeagenic Escherichia coli were investigated in 106 strains of enteropathogenic E. coli (EPEC) serogroup O86. The most frequent serotype found was O86:H34 (86%). Strains of this serotype and the non motile ones behaved as EPEC i.e., carried eae, bfpA and EAF DNA sequences and presented localised adherence to HeLa cells. Serotypes O86:H2, O86:H6, O86:H10, O86:H18, O86:H27 and O86:H non determined, belonged to other categories. The majority of the strains of serotype O86:H34 and non motile strains produced cytolethal-distending toxin (CDT). The ribotyping analysis showed a correlation among ribotypes, virulence markers and serotypes, thus suggesting that CDT production might be a property associated with a universal clone represented by the O86:H34 serotype.
- ItemSomente MetadadadosThe traditional enteropathogenic Escherichia coli (EPEC) serogroup O125 comprises serotypes which are mainly associated with the category of enteroaggregative E-coli(Elsevier B.V., 1997-07-01) Valle, GRF; Gomes, Tania Aparecida Tardelli [UNIFESP]; Irino, K.; Trabulsi, Luiz Rachid [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); INST ADOLFO LUTZ REGISTRO; Universidade de São Paulo (USP)Genotypic and phenotypic Virulence markers of the different categories of diarrheagenic Escherichia coli were investigated in 76 strains of the enteropathogenic E. coli (EPEC) serogroup O125. The most frequent serotype found was O125ac:H21. None of the serotypes behaved as EPEC, i.e. carried the eaeA, bfpA, and EAF DNA sequences simultaneously and presented localized adherence to HeLa cells. All strains of O125ac:H6 were atypical EPEC since they carried eaeA only, and presented an indefinite pattern of adherence. All strains of O125ab:H9, O125ac:H9, O125?:H16, and O125ab:H21 and 79% of the O125ac:H21 strains were enteroaggregative E. coli, since they carried a specific DNA sequence and presented the typical aggregative adherence pattern.