Title: Surface Disinfection of PSP Barriers With H2O2 vs. Phenol Wipes
Li Chen (Presenter)
University of North Carolina at Chapel Hill
Sally Mauriello, University of North Carolina-Chapel Hill
Roland Arnold, University of North Carolina at Chapel Hill
Objectives: This study evaluated the infection control protocol for photostimulable phosphor (PSP) sensors in a dental radiology setting. Two different disinfectant wipes (Oxivir® and CiDecon®) were assessed for killing oral bacteria on contaminated PSP barriers. Secondly, we compared the sporicidal activity of the two disinfect wipes.
Methods: Sealed PSP barrier bags were immersed (5 min) in overnight cultures of saliva in trypticase soy broth (TSB) adjusted to ~108 CFU/ml to simulate oral exposure. Contaminated bags were treated (3 min) with the disinfecting wipes (H2O2 or phenol respectively) or paper towels (wipe control). Individual treated barrier bags were vortexed in 20ml TSB and recoverable CFU quantitated by serial dilution and spot plating on blood agar (5% CO2 at 37oC) and by overnight culture of the resuspension TSB (recovery broth). Spore strips (MesaLabs) were treated with the disinfectant wipes compared to untreated spore strips. Spore outgrowth was determined by visual turbidity after 24-72 hour incubation in TSB at 60oC before and after serial washing to remove residual disinfectant.
Results: All wipe control bags had recoverable bacteria (>2x104 CFU) and growth in recovery broth. There were no recoverable CFU from the Oxivir®-treated bags nor was there growth in the recovery broths. CiDecon® treatment reduced CFU recovery to <2x103 and had growth in 33% of the recovery broths. Both disinfectant wipes proved sporicidal.
Conclusions: Wiping with a paper towel reduced bacterial recovery from contaminated barriers, but all barriers remained contaminated. H2O2 wipes were more effective at disinfecting surface contamination than phenol-based wipes. Both disinfecting wipes efficiently killed spores and would be an effective and practical approach to disinfect PSP barriers prior to processing.