Abstract: Aim: Biofilms which often show increased tolerance to antimicrobials and antibiotics in comparison to their planktonic counterparts, cause unresolvable inflammation and delayed wound healing. The aim of this study was to evaluate antibacterial and antibiofilm efficacy of a new diethylenetriaminepentaacetic acid (DTPA) based bimetallic complexes (MMCs) against Pseudomonas aeruginosa and Staphylococcus aureus, in comparison to complex components alone. Method: The minimum inhibitory concentration (MIC) of DTPA alone and in several different complexes with silver and various metal ions was determined using a broth microdilution method. Synergistic interactions between components of MMCs were evaluated using a checkerboard MIC method and determining the fractional inhibitory concentration index (FICI). Antibiofilm efficacy was evaluated following the ASTM E2871-13 standard for the CDC bioreactor. Biofilms were treated with MMCs for pre-defined contact times before bacterial cell density within the biofilm was enumerated. Results / Discussion: Following MIC testing, increased antimicrobial potency was found with all complexes tested compared with DTPA or metal ions alone. Checkerboard assays showed synergistic interactions between several silver compounds and DTPA, with a FICI < 0.5 against P. aeruginosa and S. aureus. The CDC biofilm model demonstrated potential antibiofilm activity of DTPA complexes with various metal ions and antimicrobial agents against P. aeruginosa and S. aureus. The complexes showed superiority to metals such as silver, copper and zinc and non-metal antimicrobials tested in parallel. Conclusion: The results demonstrate that the DTPA complexes with or without non-metal antimicrobials and surfactants represent promising next generation antibiofilm agents for use in treating at risk and infected acute and chronic wounds.
Publication Details:
Author(s): Chen, R.; Swann, M.J.; Watson, F.; Saint Bezard, J.; Percival, S.L.
Year: EWMA 2024, London, 1-3 May, 2024
Edition:
ISBN:
