Actividad bactericida de superficies de cobre frente a bacterias asociadas a infecciones nosocomiales, en un modelo in vitro de adherencia y sobrevivencia

Background Copper has a bactericidal activity against a series of bacterial strains. Aim To measure resistance to bacterial adherence of copper (Cu) and stainless steel (SS) metal coupons. Material and methods Bacterial strains causing nosocomial infections in Chile were analyzed. Bacterial adherence was studied using a previously described method based on a system of metal coupons that are immersed in culture media containing the bacteria of interest at room temperature. Results Adherence to Cu and SS coupons was different for Methicillin-resistant Staphylococcus aureus (MRSA), Klebsiella pneumoniae and Acinetobacter baumannii strains. For these strains, no adherence to Cu coupons occurred during the 48 h observation period compared to a rapidly increasing adherence to SS coupons, with a final colony count of 1.00 E + 07 cfu/mL. For two different Pseudomonas aeruginosa clinical strains, inhibition of adherence was not observed on Cu coupons, and colony counts were similar for Cu and SS using the standard inoculum (2-3 x lO7 cfu).A partial decrease in adherence was observed for Cu but not for SS coupons, when a lower inoculum was used. Conclusions Copper surfaces represent an interesting option to reduce bacterial contamination in the hospital environment due to its resistance to bacterial adhesion of most of the common nosocomial bacterial strains.