Topical antimicrobial testing of burn wound microorganisms: evaluation of a new technique

A new system of determining susceptibility of burn wound microorganisms to topical antimicrobial therapy was studied. The new method, TOPITEST, employs a methacrylate vehicle impregnated with various antimicrobial agents and an agar overlay. Test plates can be inoculated by a direct swab culture of the wound or with micro-organisms isolated by other methods. This new technique was compared to an agar well diffusion (AWD) method using commercially compounded antimicrobials and biopsy-recovered organisms. The new test method provided comparable results to the more established AWD test when using biopsy-recovered organisms. Using the swab culture technique, however, TOPITEST had a high rate of failure to recover sufficient organisms from the burn wound for testing. The new, more standardized test provided results earlier than the AWD test, but may prove to be less cost effective.