Navegando por Palavras-chave "molecular characterization"

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    Genotypic and phenotypic characterization of enterotoxigenic Escherichia coli (ETEC) strains isolated in Rio de Janeiro city, Brazil
    (Elsevier B.V., 2004-03-08) Regua-Mangia, Adriana Hamond; Guth, Beatriz Ernestina Cabilio [UNIFESP]; Andrade, João Ramos da Costa; Irino, Kinue; Pacheco, Ana Beatriz Furlanetto; Ferreira, Luís Carlos de Souza; Zahner, Viviane; Teixeira, Lúcia Martins; Fdn Oowaldo Cruz; Universidade Federal do Rio de Janeiro (UFRJ); Universidade Federal de São Paulo (UNIFESP); Universidade do Estado do Rio de Janeiro (UERJ); Inst Adolfo Lutz Registro; Fdn Oswaldo Cruz
    Enterotoxigenic Escherichia coli (ETEC) strains have been implicated as important etiological agents of diarrheal disease, especially in developing countries. This group of microorganisms has been associated with a diverse range of genotypic and phenotypic markers. in the present study, 21 ETEC isolates previously defined according to the toxigenic genotypes, were characterized on the basis of O:H typing, cell adherence patterns, and colonization factors (CFs) antigens. Genetic diversity was investigated by random amplification polymorphic DNA (RAPD-PCR), pulsed-field gel electrophoresis (PFGE) and multilocus enzyme electrophoresis (MLEE). LT-I probe-positive isolates belonged to serotypes ONT:HNT, O7:H24, 048:H21, 088:H25, O148:H28, O159:H17 and 0159:H21. ST-h probe-positive isolates belonged to serotypes O159: H17, O148: H28 and O6:H-. Serotypes O148: H28, O159: H17 and O6:H- were associated with the CS6, CFA/I and CS1 CS3 antigens, respectively. Most ETEC strains exhibited a diffuse pattern of adherence to cultured epithelial cells. in general, phenotypic and genotypic characteristics correlated well. RAPD-PCR, PFGE and MLEE showed reproducibility and good discriminatory potential. the application of molecular typing systems allowed the detection of significant diversity among the isolates,. indicating a non-clonal origin and revealing intra-serotype variation overlooked by classical epidemiological approaches. the phenotypic and genotypic diversity observed lead us to recommend the use of different typing systems in order to elucidate the epidemiology of ETEC infection. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.
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    Variant isolates of human metapneumovirus subgroup B genotype 1 in Campinas, Brazil
    (Elsevier B.V., 2008-05-01) Da Silva, Luciana Helena Antoniassi; Spilki, Fernando Rosado; Riccetto, Adriana Gut Lopes; Almeida, Renata Servan de; Baracat, Emilio Carlos Elias; Arns, Clarice Weis; Universidade Estadual de Campinas (UNICAMP); Universidade Federal de São Paulo (UNIFESP); CIRAD
    Background: Human metapneumovirus (HMPV) is a paramyxovirus associated with respiratory illness. the genotypes of HMPV isolates in Brazil have not been well characterized.Objectives: To investigate the presence of HMPV in clinical samples collected from pediatric patients of two university hospitals in the region of Campinas (São Paulo, Brazil) and to genotype them by partial sequencing of the HMPV F gene.Study design: Nasopharyngeal aspirates were collected from children hospitalized between April and September, 2004 because of acute respiratory infections (ARI).Results: We identified HMPV in 8 of 142 (5.6%) clinical samples. We determined through phylogenetic analysis that HMPV isolates in Campinas during the study were clustered within subgroup B genotype 1. Two of the isolates analyzed showed significant differences from previously isolated B I viruses, when compared to HMPV isolated in South Africa and,Canada, and clustered in a separate branch within this genotype.Conclusions: in 2004 in our geographic region all HMPV isolates from pediatric patients were in the B I HMPV genetic group, with two variant isolates. (c) 2007 Elsevier B.V. All rights reserved.