Clostridium difficile killed on exposure to surfaces made of copper and its alloys, brass and bronze

Jun 3 2008

Scientists in the Environmental Healthcare Unit at the University of Southampton in the U.K. have found that infectious bacterium Clostridium difficile is killed when exposed to surfaces made of copper and its alloys, brass and bronze. The results of the study have been published in the February 2008 issue of the Journal of Hospital Infection.

C. difficile is a leading cause of hospital infection in both the U.K. and the United States. The spores can live in the environment for a long time and are resistant to a range of disinfectants, including alcohol gel, which is recommended for routine use in hospitals.

The U.S. Environmental Protection Agency (EPA) recently approved the registration of antimicrobial copper alloys, with public health claims acknowledging that copper, brass and bronze are capable of killing harmful, potentially deadly bacteria. C. difficile is not part of this registration. The bacteria species listed in the EPA registration are: Staphylococcus aureus; Enterobacter aerogenes; Escherichia coli O157:H7 (E. coli); Pseudomonas aeruginosa; and Methicillin-resistant Staphylococcus aureus (MRSA), one of the most virulent strains of antibiotic-resistant bacteria and a common cause of hospital- and community-acquired infections.

Copper is the first solid surface material to receive this type of EPA registration, which is supported by extensive antimicrobial efficacy testing.

Bill Keevil, Ph.D., a professor at the University of Southampton and the lead researcher on the study, says the new findings are particularly significant, "We've already shown that copper surfaces can inactivate MRSA microbes. The fact that we've now established that copper also inactivates C. difficile spores, which are resistant to standard cleaning regimes, doubles our conviction that copper can play a significant role in killing those bacteria that cause hospital infections."

The Copper Development Association is the information, education, market and technical development arm of the copper, brass and bronze industries in the USA. CDA is affiliated with the International Copper Association, LTD.