The efficacy of different antimicrobial metals at preventing the formation of, and eradicating bacterial biofilms of pathogenic indicator strains.

Date
2017-02-15
Journal Title
Journal ISSN
Volume Title
Publisher
Nature
Abstract
The emergence of multidrug resistant pathogens and the prevalence of biofilm-related infections have generated a demand for alternative antimicrobial therapies. Metals have not been explored in adequate detail for their capacity to combat infectious disease. Metal compounds can now be found in textiles, medical devices, and disinfectants – yet, we know little about their efficacy against specific pathogens. To help fill this knowledge gap, we report on the antimicrobial and antibiofilm activity of seven metals; silver, copper, titanium, gallium, nickel, aluminum and zinc against three bacterial strains, Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. In order to evaluate the capacity of metal ions to prevent the growth of, and eradicate biofilms and planktonic cells, bacterial cultures were inoculated in the Calgary Biofilm Device (MBEC™) in the presence the metal salts. Copper, gallium, and titanium were capable of preventing planktonic and biofilm growth, and eradicating established biofilms of all tested strains. Further, we observed that the efficacies of the other tested metal salts displayed variable efficacy against the tested strains. Further, contrary to the enhanced resistance anticipated from bacterial biofilms, particular metal salts were observed to be more effective against biofilm communities versus planktonic cells. In this study, we have demonstrated that the identity of the bacterial strain must be considered prior to treatment with a particular metal ion. Consequently, as the use of metal ions as antimicrobial agents to fight multidrug resistant and biofilm related infections increases, we must aim for more selective deployment in a given infectious setting.
Description
Keywords
antibiofilm, antimicrobial, metals, biofilm, metal toxicity, metal tolerance
Citation
The Journal of Antibiotics (2017) 70, 775–780