Evaluation of adenosine triphosphate (ATP) bioluminescence assay to confirm surface disinfection of biological indicators with vaporised hydrogen peroxide (VHP)

BackgroundDecontamination of hospital isolation rooms can be conducted using vaporised hydrogen peroxide (VHP). A more rapid biological indicator, such as adenosine triphosphate (ATP) bioluminescence, could allow rooms to be reoccupied sooner and reduce down time.AimThis study examined the ATP bioluminescence assay as a way to evaluate biological indicators to confirm decontamination following the use of VHP.MethodsResponse to VHP exposure was evaluated using microbial inactivation by standard culture methods and by the ATP bioluminescence assay. Range finding determined the approximate exposure time necessary to achieve partial and complete inactivation of the organisms. Two-hundred-and-fifty parts per million of VHP was delivered to the chamber during the exposure cycle. Fifty cm2 stainless steel coupons were inoculated with 50 mL of organism suspensions containing >109 colony forming units (CFU) of the following: Acinetobacter baumannii, Klebsiella pneumoniae, and methicillin-resistant Staphylococcus aureus. The standard manufactured biological indicator stainless steel discs containing concentrations of 104, 105 and 106 CFU/surface of Geobacillus stearothermophilus spores were also evaluated.FindingsMultiple log-reductions were shown utilising standard culture methods for each organism, but the ATP bioluminescence assay did not show a corresponding log-reduction.ConclusionThe ATP bioluminescence assay was not considered an effective alternate to standard culture-based methodologies for the confirmation of VHP decontamination.