The effects of low-shear stress on Adherent-invasive Escherichia coli

Christopher A. Allen, David Niesel, Alfredo Torres

Research output: Contribution to journalArticle

30 Citations (Scopus)

Abstract

The impact of low-shear stress (LSS) was evaluated on an Adherent-invasive Escherichia coli clinical isolate (AIEC strain O83:H1) from a Crohn's disease patient. High-aspect ratio vessels (HARVs) were used to model LSS conditions to characterize changes in environmental stress resistance and adhesion/invasive properties. Low-shear stress-grown cultures exhibited enhanced thermal and oxidative stress resistance as well as increased adherence to Caco-2 cells, but no changes in invasion were observed. An AIEC rpoS mutant was constructed to examine the impact of this global stress regulator. The absence of RpoS under LSS conditions resulted in increased sensitivity to oxidative stress while adherence levels were elevated in comparison with the wild-type strain. TnphoA mutagenesis and rpoS complementation were carried out on the rpoS mutant to identify those factors involved in the LSS-induced adherence phenotype. Mutagenesis results revealed that one insertion disrupted the tnaB gene (encoding tryptophan permease) and the rpoS tnaB double mutant exhibited decreased adherence under LSS. Complementation of the tnaB gene, or medium supplemented with exogenous indole, restored adhesion of the rpoS tnaB mutant under LSS conditions. Overall, our study demonstrated how mechanical stresses such as LSS altered AIEC phenotypic characteristics and identified novel functions for some RpoS-regulated proteins.

Original languageEnglish (US)
Pages (from-to)1512-1525
Number of pages14
JournalEnvironmental Microbiology
Volume10
Issue number6
DOIs
StatePublished - Jun 2008

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Mutagenesis
shear stress
Oxidative Stress
Escherichia coli
Mechanical Stress
Caco-2 Cells
Crohn Disease
Genes
Hot Temperature
Phenotype
stress resistance
mutants
adhesion
mutagenesis
stress tolerance
Proteins
oxidative stress
mechanical stress
Crohn disease
effect

ASJC Scopus subject areas

  • Environmental Science(all)
  • Microbiology
  • Applied Microbiology and Biotechnology

Cite this

The effects of low-shear stress on Adherent-invasive Escherichia coli. / Allen, Christopher A.; Niesel, David; Torres, Alfredo.

In: Environmental Microbiology, Vol. 10, No. 6, 06.2008, p. 1512-1525.

Research output: Contribution to journalArticle

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