A Novel Activated Zinc Solution with Improved Efficacy Against Pseudomonas and MRSA Biofilm Compared to Chlorhexidine and Povidone-Iodine.

Introduction: The search for the optimal agent for infection eradication in periprosthetic joint infection (PJI) remains challenging as there are limited efficacious and safe options. The ideal solution should have significant bactericidal and anti-biofilm activity to be able to eradicate infection with the preservation of prosthetic components. Therefore, the purpose of this study was to 1) investigate the anti-biofilm efficacy of a novel activated zinc solution against Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) biofilm in vitro and 2) compare its efficacy against two leading commercially available antimicrobial irrigants (CHG and 0.35% povidone-iodine [PI]).

Materials And Methods: A modified Robbins device (MRD) was utilized to replicate Pseudomonas aeruginosa and MRSA biofilms. The primary outcome was to determine bacterial reduction after two hours of biofilm exposure to an activated zinc solution, CHG, and PI, and compare to untreated controls.

Results: Against Pseudomonas biofilm, activated zinc demonstrated a 4.5-log (99.996%) reduction, chlorhexidine demonstrated a 0.9-log (87.4%) reduction (p<0.001), and PI demonstrated a 0.8-log (83.1%) reduction (p<0.001). After two hours of exposure, activated zinc had undetectable MRSA with a 7.08-log (100%) reduction, chlorhexidine had a 1.9-log (98.7%) reduction (p<0.01), and PI had a 3.2-log (99.9%) reduction (p<0.01).

Conclusions: Our novel activated zinc compound demonstrated a 99.996% reduction in Pseudomonas biofilm and a 100% reduction in MRSA biofilm. This novel solution may provide a significant tool in the arsenal to treat and/or prevent PJI and other wound infections. Future in vivo studies are warranted to demonstrate clinical utility, efficacy, and safety.