Center for Biofilm Engineering

Abstract:  

"Anti-biofilm properties of chitosan-coated surfaces"
 

08-018

Surfaces coated with the naturally-occurring polysaccharide chitosan (partially deacetylated
poly N-acetyl glucosamine) resisted biofilm formation by bacteria and yeast. Reductions in
biofilm viable cell numbers ranging from 95% to 99.9997% were demonstrated for Staphylococcus epidermidis, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginosa and Candida albicans on chitosan-coated surfaces over a 54-h experiment in comparison to controls. For instance, chitosan-coated surfaces reduced S. epidermidis surface-associated growth more than 5.5 ¹⁰log units (99.9997%) compared to a control surface. As a comparison, coatings containing a combination of the antibiotics minocycline and rifampin reduced S. epidermidis growth by 3.9 ¹⁰log units (99.99%) and coatings containing the antiseptic chlorhexidine did not significantly reduce S. epidermidis surface associated growth as compared to controls. The chitosan effects were confirmed with microscopy. Using time-lapse fluorescence microscopy and fluorescent-dye-loaded S. epidermidis, the permeabilization of these cells was observed as they alighted on chitosan-coated surfaces. This suggests chitosan disrupts cell membranes as microbes settle on the surface. Chitosan offers a flexible, biocompatible platform for designing coatings to protect surfaces from infection.

"Anti-biofilm properties of chitosan-coated surfaces"

Carlson, R, Reed, T, Davison, W, Stewart, P

J. Biomater Sci Polymer Edn 2008; 19(8) 1035–1046