Antimicrobial efficacy of a silver-zeolite matrix coating on stainless steel

A silver- and zinc-containing zeolite matrix (AgION) used as a coating for stainless steel was tested for antimicrobial efficacy against Escherichia coli 25922, Staphylococcus aureus 25923, Pseudomonas aeruginosa 27853, and Listeria monocytogenes 7644. Assays were performed on flat coupon surfaces and in formed steel cups. AgION reduced microbial colony-forming units when compared to uncoated steel surfaces under all conditions tested. Percent reductions ranged from 84.536 to 99.999 after 4 h exposure, and from 99.992 to 100 after 24 h in all cases. The durability of the coatings declined most markedly when the coating had been applied with a wet process and scrubbed between uses with a test tube brush. Powder-coated surfaces cleaned with a towel retained a high degree of activity after five cycles of use.