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Introducing Shear Stress in the Study of Bacterial Adhesion
Published on: September 2, 2011
Substrata mechanical stiffness can regulate adhesion of viable bacteria
Jenny A Lichter1, M Todd Thompson, Maricela Delgadillo
1Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Biomacromolecules
|May 3, 2008
Summary
Bacterial adhesion to surfaces is influenced by material stiffness, not just surface properties. This finding suggests mechanical factors play a key role in how bacteria like Staphylococcus epidermidis colonize surfaces, impacting medical device safety.
Area of Science:
- Biomaterials Science
- Microbiology
- Surface Chemistry
Background:
- Bacterial adhesion and biofilm formation on surfaces are critical issues in healthcare, leading to hospital-acquired infections and medical device failure.
- Current research primarily focuses on the physical and chemical properties of materials to prevent bacterial colonization.
- Understanding the role of mechanical properties in bacterial adhesion is crucial for developing effective anti-adhesion strategies.
Purpose of the Study:
- To investigate the influence of material surface characteristics, particularly mechanical properties, on the adhesion and growth of Staphylococcus epidermidis.
- To explore whether prokaryotic cells exhibit mechanoselective adhesion, similar to eukaryotic cells.
- To identify novel material properties that can limit bacterial adhesion and viability on medical devices.
Main Methods:
- Fabrication of weak polyelectrolyte multilayer (PEM) thin films using poly(allylamine) hydrochloride (PAH) and poly(acrylic acid) (PAA) under varying conditions.
- Characterization of PEM thin films' physicochemical properties, including roughness, interaction energy, and charge density.
- Quantification of Staphylococcus epidermidis adhesion and subsequent colony growth on PEM films with varying mechanical stiffness.
Main Results:
- Bacterial adhesion of viable S. epidermidis showed a positive correlation with the stiffness of the polymeric substrata.
- This correlation between adhesion and stiffness was independent of surface roughness, interaction energy, and charge density.
- Similar trends were observed for both wild-type and mutant Escherichia coli, suggesting a general mechanoselective adhesion mechanism in prokaryotes.
Conclusions:
- Mechanical stiffness of substrata is a significant factor regulating bacterial adhesion and colonization.
- Prokaryotic cells, like bacteria, may possess mechanoselective adhesion mechanisms.
- Material stiffness should be considered as an additional parameter for designing surfaces to prevent bacterial adhesion and biofilm formation on medical devices.
