Ultraviolet disinfection with a novel microwave-powered device

Aims: To evaluate the antimicrobial efficacy of a novel u.v. beaker, powere d in a domestic microwave oven. Methods and Results: Three beakers were compared, with most rapid killing o btained in the Neutra Plasma 50(TM). Ultraviolet light generated within the beakers efficiently killed planktonic and surface-associated Streptococcus mutans, Pseudomonas aeruginosa, vegetative Bacillus stearothermophilus, he rpes simplex and polio viruses. Candida albicans and Mycobacterium phleii w ere less rapidly killed, and only 70% inactivation of B. stearothermophilus endospores was achieved. Irradiation for 45 s reduced viable bacterial cou nts in saliva by > 99%. Conclusions: The u.v.-generating beakers efficiently reduced viable counts of bacteria, yeast and viruses. Kinetics of killing varied, reflecting the fact that lethal mechanisms are complex, and probably depend on interplay b etween u.v. and heat. Significance and Impact of the Study: This novel method of generating u.v., using a cheap and widely available power source, provides a rapid, inexpen sive and non-toxic method of disinfection with a wide range of applications in hospitals, clinics and the home.