A PHP Error was encountered

Severity: Warning

Message: Creating default object from empty value

Filename: models/publicacao_item.php

Line Number: 20

Roles of iron acquisition systems in virulence of extraintestinal... » Isaúde
  Pesquisar Publicações Científicas  
  Especialidade: carregando especialidades...  Carregando...
Nome da revista:   Volume:   Número:
BMC microbiology [electronic resource]
2012-07-20 09:30:28

Roles of iron acquisition systems in virulence of extraintestinal pathogenic Escherichia coli: salmochelin and aerobactin contribute more to virulence than heme in a chicken infection model

Descrição: Background:Avian pathogenic Escherichia coli (APEC) and uropathogenic E. coli (UPEC) are the twomain subsets of extraintestinal pathogenic E. coli (ExPEC). Both types have multiple ironacquisition systems, including heme and siderophores. Although iron transport systemsinvolved in the pathogenesis of APEC or UPEC have been documented individually incorresponding animal models, the contribution of these systems during simultaneous APECand UPEC infection is not well described. To determine the contribution of each individualiron acquisition system to the virulence of APEC and UPEC, isogenic mutants affecting iron uptake in APEC E058 and UPEC U17 were constructed and compared in a chicken challengemodel.Results:Salmochelin-defective mutants E058DeltairoD and U17DeltairoD showed significantly decreasedpathogenicity compared to the wild-type strains. Aerobactin defective mutants E058DeltaiucDand U17DeltaiucD demonstrated reduced colonization in several internal organs, whereas theheme defective mutants E058DeltachuT and U17DeltachuT colonized internal organs to the sameextent as their wild-type strains. The triple mutant DeltachuTDeltairoDDeltaiucD in both E058 and U17showed decreased pathogenicity compared to each of the single mutants. Thehistopathological lesions in visceral organs of birds challenged with the wild-type strainswere more severe than those from birds challenged with DeltairoD, DeltaiucD or the triple mutants.Conversely, chickens inoculated with the DeltachuT mutants had lesions comparable to those inchickens inoculated with the wild-type strains. However, no significant differences wereobserved between the mutants and the wild-type strains in resistance to serum, cellularinvasion and intracellular survival in HD-11, and growth in iron-rich or iron-restrictedmedium.Conclusions:Results indicated that APEC and UPEC utilize similar iron acquisition mechanisms inchickens. Both salmochelin and aerobactin systems appeared to be important in APEC andUPEC virulence, while salmochelin contributed more to the virulence. Heme bounded byChuT in the periplasm appeared to be redundant in this model, indicating that otherperiplasmic binding proteins likely contributed to the observed no phenotype for the hemeuptake mutant. No differences were observed between the mutants and their wild-typeparents in other phenotypic traits, suggesting that other virulence mechanisms compensate forthe effect of the mutations.

Identificador: doi:10.1186/1471-2180-12-143
Volume: 0
Página: 1 a


Mais informações

  • Twitter iSaúde
publicidade
Jornal Informe Saúde

Indique o portal
Fechar [X]
  • Você está indicando a notícia: http://www.isaude.net
  • Para que seu amigo(a) receba esta indicação preencha os dados abaixo:

RSS notícias do portal  iSaúde.net
Receba o newsletter do portal  iSaúde.net
Indique o portal iSaúde.net
Notícias do  iSaúde.net em seu blog ou site.
Receba notícias com assunto de seu interesse.
© 2000-2011 www.isaude.net Todos os direitos reservados.