Impact of Oxidized Silver Wound Dressings on Wound Bacteria

Chronic non-healing wounds considerably impact quality of life in affected patients and are a substantial burden on the Canadian health care system. Microbes colonizing a chronic wound play an important role in impeding effective healing. Chronic wounds are colonized by polymicrobial communities and no single organism can be seen as causal. Only a small fraction of wound bacteria are cultured by diagnostic tests and studies have shown little agreement between culture and molecular based approaches, therefore an effective diagnostic for wound microbes is required. It is know that the composition of the microbial community associated with a wound changes as it heals although the causal relationship is somewhat unclear. Although not very effective in treating chronic non-healing wounds, antibiotics are often administered, contributing to concerns of antibiotic resistance. The wound dressings produced by Exciton Technologies Inc. (ETI) effectively aid in the healing process in chronic wounds through unknown mechanisms. ETI's wound dressings contain a combination of silver salts with three different valence, +1, +2 and +3 that have antimicrobial activity and are effective in reducing biofilm formation in vitro. However, it is not known how these silver salts impact microbial ecology of the wound and the role this plays in wound healing. The objectives of this research are to develop a new diagnostic tool based on molecular characterization of wound sites so as to predict how to best treat wounds and to identify new microbes to be targeted by ETI's technology. This project will utilize molecular microbial ecology for the assessment and evaluation of topical silver interventions, gaining insight into the management of chronic infection. Substantiating the microbiota-modifying effectiveness of silver wound dressings towards increasing clinician and patient understanding to improving clinical outcomes.