An attempt to demonstrate the increased resistance of selected bacterial strains during repeated exposure to UV radiation at 254 nm.
Evidence was provided that in a repeatedly irradiated bacterial suspension of Escherichia coil K12 : AB 1157. 1886,2463, under the described experimental conditions, gradually mutants more resistant to UV radiation survive.
Under these circumstances it may happen that selection and an increase of bacterial clones with an increased UV resistance develop, manifested by a reduced effectiveness of UV radiation during repeated irradiation.
Although the cumulating damage of DNA in microbes can lead to a reduction of their survival as well as a reduction of their absolute numbers, it can be hardly assumed that during practical use in air conditioning units or during disinfection of drinking water all bacteria will be destroyed.
In that case even repeated UV irradiation is not necessarily a reliable disinfection tool.
Mots-clés Pascal : Eau alimentation, Désinfection, Rayonnement UV, Exposition, Epidémiologie, Technique, Evaluation performance, Homme, Prévention, Santé et environnement
Mots-clés Pascal anglais : Feed water, Disinfection, Ultraviolet radiation, Exposure, Epidemiology, Technique, Performance evaluation, Human, Prevention, Health and environment
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0499031
Code Inist : 002B30A02A. Création : 19/02/1999.