An in vitro study of the anti-microbial efficacy of a 1% silver sulphadiazine and 0.2% chlorhexidine digluconate cream, 1% silver sulphadiazine cream, and a silver coated dressing,

Burn sepsis is a leading cause of mortality and morbidity in patients with major burns. The use of topical anti-microbial agents has helped improve the survival in these patients. There are a number of anti-microbials available, one of which, Silvazine™ (1% silver sulphadiazine (SSD) and 0.2% chlorhexidine digluconate), is used only in Australasia. No study, in vitro or clinical, had compared Silvazine™ with the new dressing Acticoat™. This study compared the anti-microbial activity of Silvazine™, Acticoat™ and 1% silver sulphadiazine (Flamazine™) against eight common burn wound pathogens. Methods: Each organism was prepared as a suspension. A 10 μl inoculum of the chosen bacterial isolate (representing approximately between 104 and 105 total bacteria) was added to each of four vials, followed by samples of each dressing and a control. The broths were then incubated and 10 μl loops removed at specified intervals and transferred onto Horse Blood Agar. These plates were then incubated for 18 hours and a colony count was performed. Results: The data demonstrates that the combination of 1% SSD and 0.2% chlorhexidine digluconate (Silvazine™) results in the most effective killing of all bacteria. SSD and Acticoat™ had similar efficacies against a number of isolates, but Acticoat™ seemed only bacteriostatic against E. faecalis and methicillin-resistant Staphylococcus aureus. Viable quantities of Enterobacter cloacae and Proteus mirabilis remained at 24 h. Conclusion: The combination of 1% SSD and 0.2% chlorhexidine digluconate (Silvazine™) is a more effective anti-microbial against a number of burn wound pathogens in this in vitro study. A clinical study of its in vivo anti-microbial efficacy is required.