Navegando por Palavras-chave "enteroaggregative Escherichia coli"
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- ItemSomente MetadadadosCharacterization of serotypes and outer membrane protein profiles in enteroaggregative Escherichia coli strains(Center Academic Publ Japan, 1999-01-01) Suzart, Sergio [UNIFESP]; Gomes, Tania Aparecida Tardelli [UNIFESP]; Guth, Beatriz Ernestina Cabilio [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Twenty-four Escherichia coli strains mainly isolated from children with diarrhea in Sao Paulo, and showing characteristics of enteroaggregative E, coli (EAEC), were characterized by serotyping and outer membrane protein (OMP) profiles. The relationship between these characteristics was evaluated, as well as the usefulness of OMP profiles in the clonal analysis of EAEC strains. All strains presented aggregative adherence to HeLa cells and were classified in two groups based on their interaction with the EAEC DNA probe. A diversity of serotypes and OMP profiles was observed in both groups studied. Although no significant correlation between serotypes and OMP profiles was observed, unique OMP profiles were identified in 80% of the probe-positive strains which were distributed in only 4 OMP profiles. This result may indicate the presence of a few clones in the probe-positive group, On the other hand, probe-negative strains seem to constitute a more diverse group. In general, the observed heterogeneity in serotypes and OMP profiles described in the present study suggest a great genetic diversity in EAEC isolates of either the same or different serotypes and in strains presenting the same EAEC markers identified in our community.
- ItemSomente MetadadadosDiversity of surface structures and virulence genetic markers among enteroaggregative Escherichia coli (EAEC) strains with and without the EAEC DNA probe sequence(Elsevier B.V., 2001-07-24) Suzart, Sergio [UNIFESP]; Guth, Beatriz Ernestina Cabilio [UNIFESP]; Pedroso, Margareth Z. [UNIFESP]; Okafor, Udenma M. [UNIFESP]; Gomes, Tania Aparecida Tardelli [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)The expression of surface structures and the presence of DNA sequences related to putative virulence factors were investigated in 22 enteroaggregative Escherichia coli strains (EAEC). Fimbria was the most frequent (72.7%) structure identified. Only strains hybridising with the EAEC DNA probe carried aggA, but one strain produced a similar but unrelated bundle-like structure. All probe-positive and 62.5% of the probe-negative strains carried the virulence genes tested; aspU and irp2 prevailed among the former strains. the EAEC probe-positive strains were more diverse, and some of these strains, which promoted cell detachment, also carried the hly and pap sequences, thus suggesting they might represent uropathogenic E. coli. (C) 2001 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
- ItemSomente MetadadadosEnteroaggregative Escherichia coli from humans and animals differ in major phenotypical traits and virulence genes(Blackwell Publishing, 2006-03-01) Uber, Ana Paula; Trabulsi, Luiz R.; Irino, Kinue; Beutin, Lothar; Ghilardi, Angela CR; Gomes, Tania Aparecida Tardelli [UNIFESP]; Liberatore, Ana Maria A [UNIFESP]; Castro, Antonio NFP de; Elias Junior, Waldir Pereira [UNIFESP]; Inst Butantan; Inst Adolfo Lutz Registro; Fed Inst Risk Assessment; Universidade Federal de São Paulo (UNIFESP); Universidade de São Paulo (USP)Enteroaggregative Escherichia coli (EAEC) is characterized by the expression of the aggregative adherence pattern to cultured epithelial cells. in this study, we determined the phenotypic and genotypic relationships among 86 EAEC strains of human and animal (calves, piglets and horses) feces. Serotypes and the presence of EAEC virulence markers were determined, and these results were associated with ribotyping. Strains harboring aggR (typical EAEC) of human origin were found carrying several of the searched markers, while atypical EAEC harbored none or a few markers. the strains of animal origin were classified as atypical EAEC (strains lacking aggR) and harbored only irp2 or shf. Strains from humans and animals belonged to several different serotypes, although none of them prevailed. Sixteen ribotypes were determined, and there was no association with virulence genes profiles or serotypes. Relationship was not found among the strains of this study, and the assessed animals may not represent a reservoir of human pathogenic typical EAEC.
- ItemAcesso aberto (Open Access)Escherichia coli enteroagregativa como agente provocador de diarreia persistente: modelo experimental utilizando microscopia óptica de luz(Sociedade de Pediatria de São Paulo, 2011-03-01) Andrade, Jacy Alves Braga de [UNIFESP]; Freymüller-Haapalainen, Edna [UNIFESP]; Fagundes-neto, Ulysses [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)OBJECTIVE: To examine the interactions of Enteroaggregative Escherichia coli strains with small and large intestinal mucosa, in order to detect potential alterations in both regions of the digestive tract. METHODS: Enteroaggregative Escherichia coli strains, isolated from stools of infants with persistent diarrhea and the prototype strain 042 (O44:H18), isolated from a child with diarrhea in Lima, Peru (positive control), were analised by light microscopy after in vitro organ culture assay of ileal and colonic mucosa. The interactions between the different enteroaggregative Escherichia coli strains and the ileal and colonic mucosa were analysed. RESULTS: Light microscopy analysis suggested an association of enteroaggregative Escherichia coli strains with the epithelium, inducing alterations. These bacteria adhered to both small and large bowel mucosa. The enteroaggregative Escherichia coli strains induced alterations in those areas where they were directly interacting with the epithelium. In the ileum, some areas showed a secondary internalization. CONCLUSIONS: The enteroaggregative Escherichia coli strains could cause persistent diarrhea inducing alterations in the small intestinal structures, where the digestive-absorptive functions take place. Inflammatory lesions observed in colons could justify the colitis described in some children infected by enteroaggregative Escherichia coli.
- ItemSomente MetadadadosPrevalence of HEp-2 cell-adherent Escherichia coli and characterisation of enteroaggregative E-coli and chain-like adherent E-coli isolated from children with and without diarrhoea, in Londrina, Brazil(Elsevier B.V., 2000-09-15) Gioppo, Nereida MR; Elias Junior, Waldir Pereira [UNIFESP]; Vidotto, Marilda C.; Linhares, Rosa E.; Saridakis, Halha O.; Gomes, Tania Aparecida Tardelli [UNIFESP]; Trabulsi, Luiz R.; Pelayo, Jacinta S.; Universidade Estadual de Londrina (UEL); Inst Butantan; Universidade Federal de São Paulo (UNIFESP)A total of 919 Escherichia coli isolates from 125 children with diarrhoea (cases) and 98 controls were assayed for adherence to HEp-2 cells. Localised adherence was found only in isolates from cases. Diffuse, aggregative (AA), chain-like adherence (CLA) and variants of the AA pattern were found in both cases and controls. the AA isolates were tested for gene sequences associated with enteroaggregative E. coli (EAEC). Only 25% of the isolates hybridised with the EAEC probe, and the aafA, astA and pet gene sequences were found in 7.9%, 44.7% and 7.9% of the isolates, respectively. the aggA gene was not found, although 7.9% were positive for aggC. the CLA isolates reacted with the EAEC probe (55.6%),nd the aggC, astA and pet gene sequences were found in 66.7%, 33.3% and 11.1%, respectively. the aggR (55.6%), aspU (55.6%), shf(33.3%) and she (22.2%) genes were also found in CLA isolates. (C) 2000 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
- 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.
- ItemSomente MetadadadosVirulence properties of Escherichia coli O111:H12 strains(Wiley-Blackwell, 1997-01-01) Monteiro-Neto, Valério; Campos, Leila Carvalho; Ferreira, Antonio José Piantino; Gomes, Tania Aparecida Tardelli [UNIFESP]; Trabulsi, Luiz Rachid; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)Seventeen Escherichia coli O111:H12 strains isolated from the feces of children with acute diarrhea were studied with regard to their adherence properties and other virulence characteristics. All strains showed an aggregative adherence pattern to HEp-2 cells and agglutinated bovine and sheep red cells in the presence of mannose. These strains did not have gene sequences homologous to the aggregative adherence fimbria I gene and did not react with any of the DNA probes used to detect other virulence genes in enteropathogens. With one exception, the O111:H12 strains did not induce fluid accumulation in the rabbit ileal loop assay, although 16 of the strains had the enteroaggregative E. coli heat-stable enterotoxin 1 (EAST1) gene sequences. A 60-70 MDa plasmid was present in 16 of the strains studied. We conclude that the O111 :H12 serotype, one of the first E. coli identified in infantile diarrhea, belongs to the enteroaggregative E. coli category but the genes encoding its adherence phenotype are distinct from those previously described.