Biological and genetic characteristics of uropathogenic Escherichia coli strains


Autoria(s): SILVEIRA,Wanderley Dias da; BENETTI,Fabiane; LANCELLOTTI,Marcelo; FERREIRA,Alessandra; SOLFERINI,Vera Nisaka; BROCCHI,Marcelo
Data(s)

01/12/2001

Resumo

The aim of the present study was to determine biological characteristics such as expression of fimbriae, Congo red binding, production of hemolysin and aerobactin, adhesion to HeLa and uroepithelial cells and invasion of HeLa cells by Escherichia coli isolates obtained from patients showing clinical signs of urinary tract infection (UTI). Also, the presence of genes (apa, afa, spa) for fimbria expression and cytotoxic necrotizing factors (CNF1, CNF2) was assayed using specific primers in PCR. The data obtained were compared with the clonal relationships obtained by analysis of multilocus enzyme electrophoresis (MLEE), restriction fragment length polymorphism (RFLP) of the rDNA (ribotyping) and enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR). All isolates but one presented a combination of at least two of the characteristics studied, a fact suggesting the presence of pathogenicity islands (PAIs). Diffuse adherence type to HeLa cells was observed to occur in most of the strains, but adhesion to uroepithelial cells seems to be a more reliable test to verify pathogenicity. Although four strains seemed to be able to invade HeLa cells when assayed by light microscopy, electron microscopy studies demonstrated that these strains were not invasive. MLEE, RFLP and ERIC-PCR were able to group the isolates differently into main clusters that were not correlated with the presence of pathogenic traits.

Formato

text/html

Identificador

http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0036-46652001000600001

Idioma(s)

en

Publicador

Instituto de Medicina Tropical

Fonte

Revista do Instituto de Medicina Tropical de São Paulo v.43 n.6 2001

Palavras-Chave #Escherichia coli #Clonal relationship #Urinary infection #Virulence traits #Genetic analysis
Tipo

journal article