title: Anti-biofilm properties of chitosan-coated surfaces.
abstract: 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 (10)log 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 (10)log 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.
authors.affiliation: Center for Biofilm Engineering and Department of Chemical and Biological Engineering, Montana State University, Bozeman, MT 59717, USA. rossc@erc.montana.edu
authors.forename: Ross P
authors.initials: RP
authors.lastname: Carlson
authors.forename: Reed
authors.initials: R
authors.lastname: Taffs
authors.forename: William M
authors.initials: WM
authors.lastname: Davison
authors.forename: Philip S
authors.initials: PS
authors.lastname: Stewart
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D001422:Bacterial Adhesion; D001672:Biocompatible Materials; D018441:Biofilms; D002176:Candida albicans / Q000378:metabolism; D048271:Chitosan / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D004867:Equipment Design; D007711:Klebsiella pneumoniae / Q000378:metabolism; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D011550:Pseudomonas aeruginosa / Q000378:metabolism; D013211:Staphylococcus aureus / Q000378:metabolism; D013212:Staphylococcus epidermidis / Q000378:metabolism; D013499:Surface Properties
chemical_list: D000890:Anti-Infective Agents; D001672:Biocompatible Materials; D020099:Coated Materials, Biocompatible; D048271:Chitosan