In Vitro Toxicity and Activity of Dakin's Solution, Mafenide Acetate, and Amphotericin B on Filamentous Fungi and Human Cells
Journal of Orthopaedic Trauma
Objectives: Posttraumatic invasive fungal infections threaten critically injured combat related injuries and require a combination of extensive surgery and systemic antifungal therapy, along with topical antimicro bials used adjunctively to control the infection. We evaluated the in vitro activity of topical agents in varying combinations and concentrations against molds from patients that were responsible for wound invasive fungal infections and the topical agents' toxicity to human cells.
... to human cells. Methods: Mafenide acetate solutions (2.5%, 5%, and 7.5%), amphotericin B solutions (2 mg/mL, 2 mg/mL, and 20 mg/mL), SMAT (5% mafenide acetate in combination with 2 mg/mL, 2 mg/mL, and 20 mg/mL amphotericin B), and Dakin's solutions (buffered sodium hypochlorite) (0.5%, 0.25%, and 0.125% and 10 fold serial dilutions of 0.25% 0.00000025%) were evaluated for antifungal activity against 4 molds using a time kill assay using standard conidial suspensions of 5 · 10 4 colony forming units per milliliter. To assess cellular toxicity, confluent monolayers of human keratinocytes, dermal fibroblasts, and osteoblasts were exposed to these topical agents. Based upon efficacy and toxicity ratios, an additional 10 molds were screened with selected concentrations of the topical agents for antifungal activity and toxicity. Results: All the topical agents seemed to have a dose dependent killing with only mafenide acetate showing time killing associated with prolonged contact. There was overall evidence of dose dependent cytotoxicity of the various topical agents against the various cell lines tested, but there did not seem to be increased cell death with continued exposure to the agents over time. Dakin's solution exhibited dose dependent toxicity and efficacy with 0.00025% appearing to optimize those parameters. Conclusions: Mafenide acetate and amphotericin B did not seem to persistently meet the toxicity and efficacy balance as consistently as Dakin's solution. Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. UU 18. NUMBER OF PAGES 9 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 Barsoumian et al FIGURE 5 . Representative immunofluorescent images of human keratinocytes, dermal fibroblasts, and osteoblasts demonstrating the effect of efficacious antimicrobial concentrations of Dakin's solution on cell viability and morphology after exposure for 3 hours at 378C. Images were captured at ·10 using an Olympus IX71 inverted microscope. FIGURE 6. Representative immunofluorescent images of human keratinocytes and dermal fibroblasts demonstrating the effect of various topical agents, including amphotericin B (2 mg/mL), mafenide acetate (5.0%), or SMAT (mafenide acetate 5.0% + amphotericin B 2 mg/mL) on cell viability and morphology after exposure for 3 hours at 378C. Images were captured at ·10 using an Olympus IX71 inverted microscope.