Objective: To determine the efficacy of a pulse xenon ultraviolet lamp for the disinfection of surfaces contaminated by C. diff., MRSA and VRE in the laboratory.
Methods: The test organisms (C. difficile ATCC 43598 endospores) were heat-shocked after soil addition but prior to deposition on the test coupons (glass). Following ultraviolet exposure (and separately for “time zero” controls), the endospores were cultured on blood agar “Oxyplates” with supplements. Clostridium difficile was deposited on test coupons at three separate time points (t=zero (control), t=8 minute and t=12 minutes) at a distance of 1 meter from the flashlamp, resulting in a total of nine samples. 4 samples of MRSA and 4 samples of VRE were placed on glass slides after the addition of soil, placed at a distance of 2 meters from the UV flashlamp and exposed to a UV dose of 480 seconds. The experiment was conducted at an independent microbial testing laboratory.
Results: Colony forming units (CFUs) of C. diff. averaged 3.33E+05 for the samples not exposed to the UV flashlamp (control). After an 8-minute exposure to pulse xenon ultraviolet, the average CFUs of C. diff. were 4.33E+01. After a 12-minute exposure to the pulse xenon ultraviolet, the average CFUs of C. diff. were 6.67E+00. The control samples for MRSA averaged 1.23E+05. After 480 seconds of xenon UV exposure at 2 meters, less than 10 CFUs were present. The control samples of VRE averaged 2.75E+04. After 480 seconds of xenon UV exposure, less than 10 CFUs were present.
Conclusions: Pulse xenon ultraviolet light is an effective and efficient means of disinfecting surfaces contaminated with Clostridium difficile, MRSA and/or VRE, providing an alternative means to bleach and other chemical disinfectants for use in clinical settings.