Testing the Monitoring Capability of ATP Bioluminescence

Hospital acquired infections (HAIs) have been one of the most serious complications of healthcare in recent years, causing upwards of 98,000 deaths per year. Hospitals have started using immediate feedback instruments like ATP bioluminescence assays (ATP) to determine the cleanliness of different surfaces and combat infections. The purpose of this study was to evaluate colony forming units (CFUs) and relative light units (RLUs) to determine if there was a correlation and assess a realistic benchmark for RLU counts to determine cleanliness for hospital surfaces. Five common and novel surfaces were sterilized and inoculated with MRSA to observe the cumulative bioburden on each surface type through contact plates and ATP. The surfaces were then cleaned with a disinfectant without the addition of mechanical action and tested. These results showed that hospitals cannot reasonably expect their surfaces to register at zero RLUs as nearly every surface showed no MRSA colonies after disinfection, but still had RLU values in the 10-20s. The copper sheet and solid surface with cupric oxide regularly produced the lowest RLU values, indicating that they are beneficial in retarding the viability of microbiological colonies. A test was also run in which the surfaces were only sterilized and tested for RLUs. These values were higher on average for almost every surface type, demonstrating that sterilization alone will not significantly alter the ATP bioburden on the different surfaces and that regular cleaning practices contribute to the reduction of bioburden by limiting resources for the pathogen to propagate.