Survival of methicillin-resistant Staphylococcus aureus (MRSA) on naturally contaminated dry mops.

The floors of single rooms being used by inpatients colonized by methicillin-resistant Staphylococcus aureus (MRSA) were cleaned using disposable dust-attracting dry mops. Each mop was divided into 12 sections and MRSA quantified serially. This experiment was repeated a total of 21 times for four patients. The MRSA survival rate on the dry mops compared with a control was 59.0-125% after seven days, 26.3-41.6% after 14 days, 0.1-16.2% after 28 days, 0-0.1% after 56 days and 0% after 84 days. MRSA disseminated by patients over the environment can survive for several weeks on dry mops.