Community-associated methicillin-resistant Staphylococcus aureus survival on artificial turf substrates

Artificial turf has been suggested as a risk factor for community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA). This is an experimental study looking at survival of CA-MRSA on artificial turf.

MRSA strain USA-300-0114 was grown as either planktonic cells or biofilms in liquid cultures of beef heart infusion broth overnight at 37 °C. Beakers containing ProGrass (Pittsburgh, PA) turf were inoculated at the dirt interface with either ∼5 × 10 planktonic bacteria or with biofilms. The inoculum included varying nutrient conditions consisting of spent medium, saline, or 5% mucin. The beakers were incubated at 37 °C in ambient air. The main outcome measure was the number of surviving colony-forming units determined by plating on mannitol salt agar.

Survival was biphasic with a colony-forming unit drop from ∼5 × 10 to ∼5 × 10 after the first week followed by survival of between 10 and 10 bacteria until termination of the experiment (20-50 d). Survival was dependent on nutrients, and washed cells survived less than 1 d. Mucin could serve as a nutrient source and slightly increased surviving numbers to 10-10 bacteria. Biofilm formation did not influence survival.

CA-MRSA survivability on artificial turf surfaces is dependent on the availability of nutrients. These results suggest that CA-MRSA could survive on artificial turf in significant numbers for 1 wk, and lower numbers for at least 1 month, if supplied with appropriate nutrients. Outdoor environmental conditions may affect these findings.