Bacterial resistance to silver in wound care

Ionic silver exhibits antimicrobial activity against a broad range of micro-organisms. As a consequence, silver is included in many commercially available healthcare products. The use of silver is increasing rapidly in the field of wound care, and a wide variety of silver-containing dressings are now commonplace (e.g. Hydrofiber® dressing, polyurethane foams and gauzes). However, concerns associated with the overuse of silver and the consequent emergence of bacterial resistance are being raised. The current understanding of the biochemical and molecular basis behind silver resistance has been documented since 1998. Despite the sporadic evidence of bacterial resistance to silver, there have been very few studies undertaken and documented to ascertain its prevalence. The risks of antibacterial resistance developing from the use of biocides may well have been overstated. It is proposed that hygiene should be emphasized and targeted towards those applications that have demonstrable benefits in wound care. It is the purpose of this review to assess the likelihood of widespread resistance to silver and the potential for silver to induce cross-resistance to antibiotics, in light of its increasing usage within the healthcare setting.