Formação de biofilme em amostras de Escherichia coli associada a sepse (SEPEC) : caracterização fenotipica, genotipica e filogenia / Biofilm formation by sepsis associated Escherichia coli (SEPEC) strains : genotypic, phenotypic characterization and phylogeny

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

Extraintestinal Pathogenic Escherichia coli (ExPEC) form a heterogeneous group as the bacterial virulence factors involved in its pathogenicity and local infection in the host. Our work aimed study the phenotypic and genotypic characteristics of biofilm formation and phylogeny of sepsis-associated Escherichia coli Human (SEPEC), as well as their patterns of invasion and adhesion to kidney (Vero) and endothelial (Hec-1B) cells. SEPEC showed high prevalence in the ability to form in vitro biofilm (82.2%) on plastic surfaces, suggesting involvement of type 1 fimbriae (fimH), antigen 43 (ag43) and curly fimbriae (csgA). In phylogenetic analysis, 26 (53.2%) SEPEC strains were classified as belonging to group D, 19 (38.8%) to group B2, 2 in group A (4.0%) and 2, classified as belonging to group B1 (4.0%). Others adhesins, toxins and invasin mat (adhesin temperature- egulated associated with meningitis), iha (iron-regulated adhesin), neuC (capsular polysaccharide K1), gimB (pathogenicity island associated with neonatal meningitis), ibeA (brain microvascular endothelial cells invasion) and tia (toxigenic invasion locus from Enterotoxigenic E. coli), were detected at frequencies of 38.8%, 32.7%, 24.5%, 12.2%, 10.2%, 18, 4%, 69.4% and 57.1%, respectively. In the adhesion test, 100% of SEPEC strains adhered and invaded both Vero cells and Hec-1B. Through transmission electron microscopy, were found parts of bacterial adhesion in Hec-1B cells, with the formation of pedestals between the cytoplasmic membrane and bacterial wall-cell. The scanning electron microscopy in Vero cells, showed the accession of points SEPEC on the cell surface, with the formation of microcolonies surrounded by exopolysaccharides (EPS)

ASSUNTO(S)

biofilme escherichia coli sepse sepsis filogenia biofilm phylogeny

ACESSO AO ARTIGO

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