Testing wound dressings using an in vitro wound model.
OBJECTIVE
To determine whether or not there are any significant differences in the effects of wound dressings on bacterial bioburden.


METHODS
A selection of non-occlusive, non-adhesive dressings was tested for their effect on bacterial bioburden. The dressings selected included two dressings with antimicrobial properties (one containing silver and one containing PHMB), a cotton-based dressing enclosed in a perforated sleeve of poly(ethylene terephthalate), a carboxymethyl cellulose-based dressing, a fibre-free alginate dressing, and a 12-ply 100% cotton gauze. Using the colony-drip flow reactor (DFR) model, a meticillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa biofilm was grown underneath a dressing sample. Biofilm growth was examined via plate counts, fluorescent microscopy and scanning electron microscopy.


RESULTS
The dressings containing antimicrobial agents had the greatest effect on bacterial load. In the MRSA experiments, both antimicrobial dressings produced lower bacteria counts than the other dressings (p<0.001), while in the P. aeruginosa experiments, only the silver-containing sample had fewer bacteria (p<0.0001). However, neither antimicrobial dressing was able to completely eradicate the bacteria when testing with either microorganism.


CONCLUSIONS
The results presented herein illustrate that bacteria can grow unchallenged within the dressing environment and that an antimicrobial dressing can limit this bacterial growth.


BACKGROUND
None.
Lipp
C
C
Biofilm Engineering, Montana State University, Bozeman, Montana, USA.
Kirker
K
K
Agostinho
A
A
James
G
G
Stewart
P
P
D000890:Anti-Infective Agents / Q000008:administration & dosage* / Q000494:pharmacology; D001458:Bandages; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development*; D002478:Cells, Cultured; D015169:Colony Count, Microbial; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development*; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000254:growth & development*; D014947:Wounds and Injuries / Q000382:microbiology / Q000628:therapy*
D000890:Anti-Infective Agents