Fibrous Catalyst–Enhanced Acanthamoeba Disinfection by Hydrogen Peroxide

Hydrogen peroxide (H(2)O(2)) disinfection systems are contact-lens-patient problem solvers. The current one-step, criterion-standard version has been widely used since the mid-1980s, without any significant improvement. This work identifies a potential next-generation, one-step H(2)O(2), not based on the solution formulation but rather on a case-based peroxide catalyst. PURPOSE: One-step H(2)O(2) systems are widely used for contact lens disinfection. However, antimicrobial efficacy can be limited because of the rapid neutralization of the peroxide from the catalytic component of the systems. We studied whether the addition of an iron-containing catalyst bound to a nonfunctional propylene:polyacryonitrile fabric matrix could enhance the antimicrobial efficacy of these one-step H(2)O(2) systems. METHODS: Bausch + Lomb PeroxiClear and AOSept Plus (both based on 3% H(2)O(2) with a platinum-neutralizing disc) were the test systems. These were tested with and without the presence of the catalyst fabric using Acanthamoeba cysts as the challenge organism. After 6 hours' disinfection, the number of viable cysts was determined. In other studies, the experiments were also conducted with biofilm formed by Stenotrophomonas maltophilia and Elizabethkingia meningoseptica bacteria. RESULTS: Both control systems gave approximately 1-log(10) kill of Acanthamoeba cysts compared with 3.0-log(10) kill in the presence of the catalyst (P < .001). In the biofilm studies, no viable bacteria were recovered following disinfection in the presence of the catalyst compared with ≥3.0-log(10) kill when it was omitted. In 30 rounds' recurrent usage, the experiments, in which the AOSept Plus system was subjected to 30 rounds of H(2)O(2) neutralization with or without the presence of catalytic fabric, showed no loss in enhanced biocidal efficacy of the material. The catalytic fabric was also shown to not retard or increase the rate of H(2)O(2) neutralization. CONCLUSIONS: We have demonstrated the catalyst significantly increases the efficacy of one-step H(2)O(2) disinfection systems using highly resistant Acanthamoeba cysts and bacterial biofilm. Incorporating the catalyst into the design of these one-step H(2)O(2) disinfection systems could improve the antimicrobial efficacy and provide a greater margin of safety for contact lens users.