Efficacy of copper-impregnated antimicrobial surfaces against spores.

OBJECTIVE

() is one of the most common causes of healthcare-associated infections (HAIs). Elimination of spores is difficult as they are resistant to common hospital-grade disinfectants. Copper-impregnated surfaces provide continuous reduction of multiple pathogens, potentially lowering the risk of infections. This manuscript aims to evaluate the efficacy of copper-impregnated surfaces on spores.

METHODS

Control (no copper) coupons and copper coupons containing 20% copper-oxide were inoculated with spore loads ranging from 10 to 10 spores, with or without 5% fetal bovine serum soil load. After 4 hours of contact time, the spores were recovered, plated on growth media, and colony forming units were counted. The efficacy of copper (log kill) was estimated using a Bayesian latent variables model.

RESULTS

After 4 hours, unsoiled copper bedrail and copper table coupons at mean spore inoculation resulted in a 97.3% and 96.8% reduction in spore count (1.57 and 1.50 log kill, respectively). That of soiled bedrail and table coupons showed a 91.8% and 91.7% reduction (1.10 and 1.10 log kill, respectively).

CONCLUSIONS

Copper coupons can substantially reduce spores after 4 hours, but results vary depending on the initial spore concentration and presence or absence of organic material. Higher initial spore loads or excess organic material may prevent spores from contact with copper surfaces, thus decreasing kill efficacy. Continuous sporicidal effect of copper-impregnated surfaces may decrease spore burden and help prevent transmission of spores.