An Evaluation of Methicillin-Resistant Staphylococcus Aureus Survival on Five Environmental Surfaces

This study evaluated methicillin-resistant Staphylococcus aureus (MRSA) survival on environmental surfaces: glass, wood, vinyl, plastic, and cloth. Effects of relative humidity (RH) and bovine serum albumin (BSA) were examined. Surfaces were inoculated with 10(7)-10(8) colony forming units per milliliter (CFU/ml)of MRSA with and without 1% BSA and incubated at 35°C at 45%-55% and 16% RH. Surfaces were sampled, and each collected sample was re-suspended in phosphate buffer, spread plated, and incubated at 35°C for 24 hrs; resulting colonies were enumerated. Samples were collected immediately on drying, and at 3 hrs, 24 hrs, 2 days, 3 days, 4 days, and 5 days. Results demonstrated that MRSA survived the longest on plastic and vinyl and for the least amount of time on wood (p \u3c 0.001). BSA enabled MRSA to survive for significantly longer duration (p \u3c 0.001). The number of CFU/ml was significantly lesser on surfaces stored in 45%-55% RH versus 16% RH. This study demonstrates that viable MRSA bacteria can remain on surfaces for days, which may impact the public health of occupants in workplace and residential settings