Monofilament debriding mitt reduces biofilm levels in a porcine ex vivo model and in murine excisional wounds

Introduction

Debridement remains the foundation to wound bed preparation, removing non-viable tissue and biofilm infections. Recently, monofilament debriding devices have emerged as an easy and convenient alternative to traditional surgical debridement. The advantages are ease of application, reduced pain and reduced need for clinically trained personnel. However, data on the efficacy of monofilament debridement to remove biofilm infection is limited.

Methods

Here we assess the effectiveness of a monofilament debriding mitt consisting of polyester fibres, to remove biofilms. Pseudomonas aeruginosa (NCTC 10780) biofilms were grown for 24 or 48 hours in vitro before applying to porcine skin for an additional 24 hours. Biofilm removal was assessed by attaching the monofilament debriding mitt to a computer-controlled, mechanical brushing device. Biofilm were brushed in a linear fashion for 50 cycles at a constant rate and pressure. Remaining biofilm was visualised and quantified with the cell viability dye, presto blue and scanning electron microscopy (SEM).

In addition, 72 hour P. aeruginosa biofilms were applied to excisional mouse wounds and allowed to attach and grow for a further 72 hours, after which wounds were debrided with the monofilament debriding mitt. Remaining bacteria was quantified by standard plate counts.

Results

Quantification of viable 24 and 48 hour biofilms remaining on the porcine skin revealed significantly less biofilm when debridement was performed with the monofilament debriding mitt compared to NA Gauze control (P<0.05, Mann-Whitney U test). Visualisation of remaining biofilm by SEM confirmed reduced bacteria when debridement was performed with the monofilament debriding mitt. In addition, monofilament debridement significantly reduced biofilm levels in the mouse wound model (P<0.05, Mann-Whitney U test).

Conclusions

Monofilament debriding mitt effectively removes P. aeruginosa biofilms from wounds and therefore acts as a less invasive method of wound debridement than traditional sharps debridement.