Can pre-operative skin marking transfer methicillin-resistant Staphylococcus aureus between patients? A laboratory experiment.

National guidelines state that in patients undergoing operations the site of the procedure should be marked. In clinical practice the same marker is used repeatedly. We are not aware of any investigation regarding the theoretical risk of transferring organisms such as methicillin-resistant Staphyloccocus aureus (MRSA) between patients by a skin marker. In an experimental setting, Penflex and Viomedex skin markers were tested 30 times each after contaminating them with a standard inoculum of MRSA. The survival of the organism on the tip of the markers was assessed by culture on MRSA-indicator nutrient agar plates at 0, 5, 15 and 60 minutes, 24 and 48 hours and at 1, 2, and 3 weeks after contamination. There was a significant difference between the markers, with the Penflex showing no survival of MRSA after 15 minutes whereas the Viomedex product continued to produce MRSA cultures for up to three weeks.