Survival of Clostridium difficile on copper and steel: futuristic options for hospital hygiene.

Clostridium difficile is rapidly becoming a major cause of hospital-acquired infections worldwide, due in part to transmission of the faecal pathogen between contaminated hands and contact surfaces. Accordingly, this study evaluated survival of C. difficile vegetative cells and spores on the contact surface commonly found in healthcare settings, stainless steel, compared to five copper alloys (65-100% copper content). C. difficile requires prolonged incubation to grow and therefore the total number and number of viable cells was estimated using a fluorescence dual-staining technique. For viability assessment the redox dye 5-cyano-2,3-ditolyl tetrazolium (CTC) was used to measure metabolic activity. Results demonstrated that copper alloys with a copper content >70% provide a significant reduction in survival of C. difficile vegetative cells and spores on copper alloys compared with stainless steel. Complete death of spores was observed after 24-48 h on copper alloys whereas no significant death rate was observed on stainless steel even after 168 h. The use of CTC gave comparable results to culture and offers a more rapid viability analysis (8 h) than culture. The results suggest that using copper alloys in hospitals and other healthcare facilities could offer the potential to reduce spread of C. difficile from contaminated surfaces.