The effect of a Hydro-Responsive Wound Dressing (Hydroclean®) on mature biofilms in vitro

Wound bed preparation utilizing the T.I.M.E principal is integral to removing barrier to nonhealing. The presence of bacteria, either in planktonic or biofilm phenotype can aid in the chronicity of wounds and their control / removal may augment wound healing.

Method

107 – 108 cells/ml of P. aeruginosa (ATCC 25619) and 106 S. aureus ATCC 25923 biofilm was grown under shear (130 r.p.m.) on polycarbonate coupons in a CDC biofilm reactor (BioSurface Technologies Corp., Bozeman, MT). Three coupons each with biofilm was incubated in the ringer’s solution that was completely expelled from a Hydro-Responsive Wound Dressing (Hydroclean®, Paul Hartmann) and the dressing placed on top for 24-hour exposure time. Outcome measures were assessed for bacterial cell viability pre-and postexposure using BacLight™ (Live/Dead Bacterial Viability Kit, 7012, Molecular Probes, Invitrogen, Carls-bad, CA, USA) with CLSM and expressed as percentage viability. Pre-and post-exposure average CFU/mL counts per coupon was expressed as Log10.

Results

In vitro assessment demonstrated variable efficacy against the test strains. The Hydroclean® dressing demonstrated a 0.7 Log10 reduction against S. aureus and a 1.1 Log10 reduction against P. aeruginosa. Live/Dead stain identified that 93% of S. aureus cells were still viable at 24 hours (Live – 93.2% vs Dead – 6.8%), in contrast to only 28% of P. aeruginosa (Live – 28% vs Dead – 72%).

Conclusion

These findings suggest that Hydroclean®may be safe for use in wounds with potential biofilm. Whilst not possessing an active antimicrobial release, the hydro active dressing that contains PHMB within its fibres, will not promote or enhance increased microbial loads from chronic wounds requiring autolytic debridement. The intense rinsing effects of the Hydroclean® dressing may physically disrupt the outer layers of biofilm and any planktonic microorganisms that may be absorbed and bound to the superabsorbent polyacrylate (SAP)

Malone M.
Malone M, High Risk Foot Service, Liverpool Hospital, South West Sydney LHD, Sydney, Australia. Molecular Medicine Research Group, Microbiology & Infectious Diseases, School of Medicine, Western Sydney University, Sydney, Australia. Molecular Medicine Research Group, Microbiology & Infectious Diseases, School of Medicine, Western Sydney University, Sydney, Australia

Johani K.
Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia

Hu H.
Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia

Vickery K.
Surgical Infection Research Group, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia