Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2016

Antimicrobial Efficacy of Acticoat Treated with Saline vs. Water on Common Burn Wound Pathogens (#360)

Joanneke Beekman 1 2 3 , Monica Stelmach 4 , Steven Siarakas 4 , Elaine Cheong 4 , Peter Maitz 1 2 3 , Zhe Li 1 2 3
  1. Burns Research, ANZAC Research Institute, Sydney , NSW
  2. Burns Unit, Concord Repatriation General Hospital, Sydney, NSW
  3. Sydney Medical School, University of Sydney, Sydney, NSW
  4. Microbiology Department, Concord Repatriation General Hospital, Sydney, NSW

Background

Silver is known for its antimicrobial properties. Acticoat, a nanocrystalline silver dressing, is commonly used clinically for preventing and managing burn wound infections. There has been a major concern that silver ions could react with anions such as chloride and may lose its antimicrobial activities, instantly or over time. However, evidence for this effect is lacking.

 

Aims

The aim of this study is to seek evidence on the impact of chloride on the activity of silver ions in silver dressing, mimicking clinical use. Data from this study will facilitate the development of a clinical guideline for better use of silver dressings in wound infection management.

 

Material and Methods

Discs (6mm in diameter) of Acticoat were prepared with water and saline for this study. The discs were dampened with a small volume of solution to mimic clinical settings. The antimicrobial activity was tested by disk diffusion with Klebsiella pneumoniae (ESBL), MRSA, Pseudomonas aeruginosa, and Escherichia coli. Zone sizes were read at 24 and 72 hours.

 

Results

Testing showed no significant difference between the use of saline to water on the antimicrobial activity of Acticoat on any of the pathogens. E.coli, MRSA, and P. aeruginosa all showed similar zones of inhibitions yet K. pneumoniae showed a more sensitive reaction. Compared to E.coli, it showed a 24% increase in zone of inhibition after 24 hours. After 72 hours K.pneumoniae showed signs of resistance with double zoning and antimicrobial activity dropping. Despite this decrease in activity, it still had a 12% larger zone of inhibition compared to E.coli.

 

Conclusion

Despite the concerns of chloride inactivating silver dressings, this study found that antimicrobial activity of Acticoat remains intact against E.coli, K. pneumoniae, MRSA and P. aeruginosa in an anion-rich environment. Furthermore, Acticoat shows especially to be an effective against K. pneumomiae. Further research needs to investigate the effects of water compared to saline on other burn pathogens such as VRE.