As discussed over the previous two weeks’ articles, biofilms are communities of microorganisms that attach to the wound surface encasing themselves in an extracellular polysaccharide matrix.1 As biofilms can present a real barrier to wound healing, it is important that they are identified and dealt with as a matter of priority.2

The  first  step towards  managing a biofilm-related infection is achieving early  detection.1  Biofilms are less sensitive to both nutritional stimulation and hostile attacks than planktonic cells, and are therefore difficult  to  detect  using traditional  agar  and  culture -based  detection  methods.  Biofilms usually need to be detected by direct  microscopic examination  or  molecular  techniques – procedures that are unfortunately not a routine part of most wound management.

Once a biofilm has been identified, action can be taken to combat it. As commercial  topical  agents and wound dressings currently in use are ineffective  against the  biofilm matrix, multiple strategies including wound debridement and use of anti-biofilm agents should be employed.1

Sharp and ultrasonic debridement has been shown to open up all the devitalized tissue including tunnels and undermining to remove biofilms.3,4  However, no form of debridement will remove all traces of the biofilm, and any remaining bacteria have the potential to re-form the biofilm. Debridement has therefore been recommended weekly with appropriate adjunct therapies.4

Systemic broad spectrum antibiotics, together with broad spectrum topical antiseptics, may be helpful in suppressing the many subpopulations within wound biofilm.5 Systemic antibiotics that are known to be effective by interfering with the cell membrane may also be helpful.5

The mainstay of biofilm management currently is the use of biocides or antiseptics, including ionic silver. Ionic silver has been used for hundreds of years and has demonstrated its effectiveness against many bacteria. Ionic silver is currently incorporated into many wound care dressings and the antimicrobial effect has been proven.3

New approaches to the management of biofilms include the development of quorum-sensing inhibitors such as RNA III inhibitory peptide.3 Research is underway to identify other quorum-sensing inhibitors, as well as anti-adhesion agents and species-specific  killing strategies.

After  two  decades  of  relentless effort and a quarter of a million publications, the  first  anti-biofilm-based product has yet to be launched.  The hopes of designing an effective strategy against biofilms rest in the new approaches currently under research. Until such new strategies are readily available, wound care professionals must to manage biofilms using  any means at their disposal. 

Management of biofilms is complex, and no single strategy is appropriate for all cases. To learn more about managing this complex phenomenon and other advanced wound care issues, consider pursuing further wound care studies as part of your ongoing professional development. Visit www.woundeducators.com for more information on how to study for a certification in wound care.

Scanning electron micrograph of a Staphylococcus biofilm3

1.         Image reproduced from Spear M. Wound Care Management: The biofilm challenge: breaking down the walls. Plastic Surgical Nursing. 2011; 31:117-120. 

References

2.         Chen Li and Wen Y-m. The role of bacterial biofilm in persistent infections and control strategies. Int J Oral Sci. 2011; 3:66-73.

3.         Myers BA. Wound management principles and practice. 2nd ed. Upper Saddle River, NJ: Pearson; 2008.

4.         Spear M. Wound Care Management: The biofilm challenge: breaking down the walls. Plastic Surgical Nursing. 2011; 31:117-120.

5.         Wolcott R., Rhoads D. A study of biofilm-based wound management in subjects with critical limb ischaemia. J Wound Care, 2008; 17(4): 145-155.

6.         Rhoads D., Wolcott R., Cutting K., Percival S. (2007). Evidence of biofilms in wounds and the potential ramifications. BiofilmClub. Retrieved May 21, 2011, from www.woundspeciallist.com