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P pili in uropathogenic E. coli are composite fibres with distinct fibrillar adhesive tips

M J Kuehn1, J Heuser, S Normark

  • 1Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, Missouri 63110.

Nature
|March 19, 1992
PubMed

Insights

Escherichia coli uses P pili tip fibrillae, containing the PapG adhesin, to bind to digalactoside receptors in the urinary tract, causing infections. This binding is crucial for bacterial colonization and pathogenesis.

Area of Science:

  • Microbiology
  • Molecular Biology
  • Pathogenesis

Background:

  • Escherichia coli is a common cause of human and animal infections, including urinary tract infections and neonatal meningitis.
  • Microbial attachment to host surfaces is essential for bacterial colonization and infection, often mediated by adhesins on pili.
  • P pili are critical for uropathogenic E. coli (UPEC) binding to digalactoside receptors in the urinary tract epithelium.

Purpose of the Study:

  • To investigate the structural organization of adhesins within P pili.
  • To elucidate the role of tip fibrillae in the binding mechanism of uropathogenic E. coli.

Main Methods:

  • Characterization of fibrillar structures at the tips of P pili.
  • Analysis of the composition and function of tip fibrillae, including the PapG adhesin.

Main Results:

  • Virulence-associated tip fibrillae were identified at the tips of P pili.
  • These fibrillae are flexible polymers primarily composed of PapE subunits.
  • The PapG adhesin, which binds alpha-D-galactopyranosyl-(1-4)-beta-D-galactopyranose (Gal alpha (1-4)Gal), is frequently located at the termini of these fibrillae.

Conclusions:

  • Tip fibrillae play a key role in presenting the PapG adhesin for receptor binding.
  • The specific structure and localization of these fibrillae facilitate E. coli colonization of the urinary tract.
  • Understanding these adhesin-receptor interactions is vital for developing strategies against E. coli infections.

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