[Use of UV rays for the disinfection of water. III. UV sensitivity of Legionella pneumophila of different ages in cold and warm drinking water].
In drinking water the sensitivity of L. pneumophila serogroup 1 type Philadelphia and L. pneumophila serogroup 5 type Dallas were studied with a flowthrough u.v. light treatment apparatus. By washing purified cells from broth cultures were used as inoculum directly ( = young cultures) or kept 2-3 weeks in drinking water in the dark ( = old cultures). A decrease of 99,9999% was found after u.v. treatment by 19 mWs/cm2 for young cultures and by 15 mWs/cm2 for old cultures. Reductions of 99,9999% were obtained by 16 mWs/cm2 in cold drinking water (13-16 degrees C) and by 13 mWs/cm2 in warm drinking water (45-47 degrees C). L. pneumophila serogroup 1 and L. pneumophila serogroup 5 show a very similar susceptibility to u.v.-irradiation. Reductions of 99,9999% were obtained by 14 mWs/cm2 and 15 mWs/cm2, respectively. Thus L. pneumophila-suspensions proved to be more sensitive to u.v.-irradiation than E. coli oder E. faecium in earlier experiments.
Institut für Hygiene Freien Universität Berlin.
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D000367:Age Factors; D004203:Disinfection / Q000379:methods*; D004307:Dose-Response Relationship, Radiation; D007875:Legionella / Q000145:classification / Q000528:radiation effects*; D012703:Serotyping; D013242:Sterilization / Q000379:methods*; D013696:Temperature; D014466:Ultraviolet Rays; D014871:Water Microbiology
Anwendung von UV-Strahlen zur Desinfektion von Wasser III. Mitteilung: UV-Sensibilität von Legionella pneumophila unterschiedlichen Alters in kaltem und warmem Trinkwasser.