An in vitro test of the efficacy of silver-containing wound dressings against Staphylococcus aureus and Pseudomonas aeruginosa in simulated wound fluid

• Published in: International journal of pharmaceutics 2014-02, Vol.462 (1-2), p.123-128
• Main Authors: Said, Jawal, Dodoo, Cornelius C., Walker, Michael, Parsons, David, Stapleton, Paul, Beezer, Anthony E., Gaisford, Simon
• Format: Article
• Language: English
• Subjects: Anti-Infective Agents, Local - administration & dosage; Anti-Infective Agents, Local - chemistry; Anti-Infective Agents, Local - pharmacology; Bandages; Biological Availability; Calorimetry; Isothermal calorimetry; Microbial Sensitivity Tests; Pseudomonas aeruginosa; Pseudomonas aeruginosa - drug effects; Pseudomonas Infections - drug therapy; Silver Compounds - administration & dosage; Silver Compounds - chemistry; Silver Compounds - pharmacology; Silver Nitrate - administration & dosage; Silver Nitrate - chemistry; Silver Nitrate - pharmacology; Silver, Efficacy; Staphylococcal Infections - drug therapy; Staphylococcus aureus; Staphylococcus aureus - drug effects; Wound dressings; Wound Infection - drug therapy; Wound Infection - microbiology
• ISSN: 0378-5173; 1873-3476
• DOI: 10.1016/j.ijpharm.2013.12.037

An isothermal microcalorimetric assay was used to quantify the efficacy of a silver-containing wound dressing against two common wound pathogens, Pseudomonas aeruginosa and Staphylococcus aureus. The growth patterns of the two species were unique and varied depending on the environment in which the organisms were grown. Addition of non-silver-containing dressing altered the growth kinetics while addition of silver (contained either in a dressing or as AgNO3 solution) was seen to elicit inhibition and/or kill depending on concentration. Tests were conducted in nutrient broth and simulated wound fluid. It was found that minimum inhibitory and minimum bactericidal concentration values were higher in simulated wound fluid and under anaerobic conditions. Bioavailability of silver from the wound dressing was 35% against S. aureus in nutrient broth and 68% against both species in simulated wound fluid. The data highlight the importance of developing and conducting in vitro assays in biorelevant media.