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Bile Salt-induced Biofilm Formation in Enteric Pathogens: Techniques for Identification and Quantification
Published on: May 6, 2018
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Structure and function of enterotoxigenic Escherichia coli fimbriae from differing assembly pathways
Narges Mortezaei1, Chelsea R Epler, Paul P Shao
1Department of Physics, Umeå University, SE-901 87, Umeå, Sweden.
Molecular Microbiology
|October 31, 2014
Summary
Enterotoxigenic Escherichia coli (ETEC) use adhesive fimbriae to colonize the gut. Their unwinding force varies, with P-fimbriae requiring the most force, impacting bacterial adhesion and disease.
Area of Science:
- Microbiology
- Structural Biology
- Biophysics
Background:
- Enterotoxigenic Escherichia coli (ETEC) cause significant diarrheal disease in children and travelers.
- Adhesive fimbriae are critical virulence factors for ETEC, mediating intestinal colonization.
- Fimbriae assembly in Gram-negative bacteria occurs via distinct pathways, influencing their structure and function.
Purpose of the Study:
- To elucidate the structural and biophysical adaptations of ETEC fimbriae to their host niches.
- To compare the mechanical properties of CS20 fimbriae, colonization factor antigen I (CFA/I) fimbriae, and P-fimbriae.
- To understand how fimbrial structure influences bacterial adhesion and pathogenicity.
Main Methods:
- Electron microscopy for structural reconstructions.
- Computational modeling to analyze fimbrial conformations.
- Force spectroscopy to measure fimbrial unwinding forces.
Main Results:
- Fimbriae exhibit force-induced unwinding from helical to linear conformations, sustaining bacterial adhesion.
- Colonization factor antigen I (CFA/I) fimbriae required the least force to unwind, followed by CS20 fimbriae, and then P-fimbriae.
- Significant differences in unwinding forces correlate with the specific host niche targeted by each fimbrial type.
Conclusions:
- The host niche critically influences the biophysical properties of fimbriae.
- Fimbrial mechanical properties are key determinants of bacterial pathophysiology and virulence.
- Understanding fimbrial adaptations provides insights into ETEC pathogenesis and potential therapeutic targets.
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