Abstract: Aim: Evaluate the speed of kill and antibiofilm efficacy of several EDTA complexes against Pseudomonas aeruginosa and Staphylococcus aureus, in comparison to complex components alone. Method: The speed of kill was evaluated using a log reduction assay. Overnight cultures were adjusted to 0.5 McFarland (~1 x 108 CFU/mL) and used to inoculate test articles at a final cell density of ~1 x 107 CFU/mL. Test articles were incubated for pre-defined contact times and at each contact time samples were taken, neutralised, serial diluted 1:10 in PBS and plated onto TSA in duplicate. Antibiofilm efficacy was evaluated following ASTM E2799-17 ‘standard test method for testing disinfectant efficacy against Pseudomonas aeruginosa biofilm using the MBEC assay’ or E2871-13 ‘standard test method for evaluating disinfectant efficacy against Pseudomonas aeruginosa biofilm grown in CDC biofilm reactor using single tube method.’ Biofilms were treated for pre-defined contact times before being transferred to the appropriate neutraliser, sonicated, serial diluted 1:10 in PBS and plated onto TSA in duplicate. Results / Discussion: Following speed of kill and antibiofilm efficacy testing of EDTA complexes with various metal ions and antimicrobial agents, potent antimicrobial and antibiofilm activity was demonstrated against P. aeruginosa and S. aureus. The complexes showed superiority to metals such as silver and copper tested in parallel. Conclusion: The results outlined in this study demonstrate that the EDTA complexes could be used in the clinic for treatment of biofilms, such as those that form in chronic wounds.
Publication Details:
Author(s): Salisbury, A-M; Law, S.; Foulkes, L.; Mullin, M.; Chen, R.; Percival, S.L.
Year: EWMA 2020, London, 13-15 May, 2024.
Edition:
ISBN:
