A comparison of the antimicrobial effects of four silver-containing dressings on three organisms

To compare the antimicrobial activity of four silver-containing dressings: Acticoat (Smith and Nephew), Actisorb Silver 220 (Johnson and Johnson), Avance (SSL International) and Contreet-H (Coloplast).

The dressings were tested against three micro-organisms: a Gram-positive bacterium, Staphylococcus aureus; a Gram-negative organism, Escherichia coli; and a yeast, Candida albicans, using three different techniques. Each dressing also had its silver content analysed.

Acticoat is likely to produce the most rapid antimicrobial effect in vitro because of the rapid release of relatively large concentrations of highly active silver ions. Contreet-H has broadly similar antimicrobial activity to Acticoat, but has a slower onset of action. Actisorb Silver 220 appears to offer less prospect of killing bacteria within the wound itself, but the dressing is capable of removing micro-organisms from wound exudate and sequestering them until they are inactivated by the silver within the charcoal fibres. Little convincing evidence for any antimicrobial activity of Avance was found.

Although caution must always be exercised when extrapolating the results of laboratory-based studies to the clinical situation, potentially important differences were detected in the antimicrobial activity of the four products examined. It is also possible that the silver ions released by the dressings may have effects on wound healing that are unrelated to their antimicrobial activity. Further work is needed to address this issue.