The author studied the effect of ultraviolet lamp (manufactured by Chun Woo Indusrial Co. Ltd. , Seoul Korea) on the growth of various strains of staphylococcus, E. coli, Salmonella typhi and Bacillus subtilis seeding on flat surface, and on the organisms suspended in operating room air.
Gram negative bacteria such as E. coli and S. typhi were killed by the irradiation of 20 minutes. However, staphylococcus was killed by the irradiation of 30 minutes.
Bacillus subtilis was killed by 50 minutes´ irradiation, indicating sporeforming bacteria were more resistant to ultraviolet than nonsporeforming bacteria.
The number of sedimenting viable bacteria after one and two hours´ irradiation of operating room air were reduced to 25% and 6%, respectively, suggesting sterilizing power of ultraviolet lamp was relatively prominent.
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