Contamination of hot water distribution systems by Legionella represents a great challenge due to difficulties associated with inactivating microorganisms, preserving the watercharacteristics. The aim of this study was to examine over thecourse of 1 year in 11 fixed sites, the impact of monochloraminedisinfection on Legionella, heterotrophic bacteria (36 °C), Pseudomonas aeruginosa contamination, and chemical parameters of a plumbing system in an Italian hospital. Three days after installation (T0), in the presence of monochloramine concentration between 1.5 and 2 mg/L, 10/11 sites (91%) were contaminated by L. pneumophila serogroups 3 and 10. After these results, the disinfectant dosage was increased to between 6 and 10 mg/L, reducing the level of Legionella by three logarithmic unit by 2 months postinstallation (T2) until 6 months later (T3). One year later (T4), there was a significant reduction (p = 0.0002) at 8/11 (73%) sites. Our data showed also a significant reduction of heterotrophic bacteria (36 °C) in 6/11 (55%) sites at T4 (p = 0.0004), by contrast the contamination of P. aeruginosa found at T0 in two sites persisted up until T4. The results of the present study show that monochloramine is a promising disinfectant thatcan prevent Legionella contamination of hospital water supplies.
Effect of Monochloramine Treatment on Colonization of a Hospital Water Distribution System by Legionella spp.: A 1 Year ExperienceStudy / Benedetta Mancini; Maria Scurti; Ada Dormi; Antonella Grottola; Andrea Zanotti; Sandra Cristino. - In: ENVIRONMENTAL SCIENCE & TECHNOLOGY. - ISSN 0013-936X. - ELETTRONICO. - 49:(2015), pp. 4551-4558. [10.1021/es506118e]
Effect of Monochloramine Treatment on Colonization of a Hospital Water Distribution System by Legionella spp.: A 1 Year ExperienceStudy
MANCINI, BENEDETTA;SCURTI, MARIA;DORMI, ADA;CRISTINO, SANDRA
2015
Abstract
Contamination of hot water distribution systems by Legionella represents a great challenge due to difficulties associated with inactivating microorganisms, preserving the watercharacteristics. The aim of this study was to examine over thecourse of 1 year in 11 fixed sites, the impact of monochloraminedisinfection on Legionella, heterotrophic bacteria (36 °C), Pseudomonas aeruginosa contamination, and chemical parameters of a plumbing system in an Italian hospital. Three days after installation (T0), in the presence of monochloramine concentration between 1.5 and 2 mg/L, 10/11 sites (91%) were contaminated by L. pneumophila serogroups 3 and 10. After these results, the disinfectant dosage was increased to between 6 and 10 mg/L, reducing the level of Legionella by three logarithmic unit by 2 months postinstallation (T2) until 6 months later (T3). One year later (T4), there was a significant reduction (p = 0.0002) at 8/11 (73%) sites. Our data showed also a significant reduction of heterotrophic bacteria (36 °C) in 6/11 (55%) sites at T4 (p = 0.0004), by contrast the contamination of P. aeruginosa found at T0 in two sites persisted up until T4. The results of the present study show that monochloramine is a promising disinfectant thatcan prevent Legionella contamination of hospital water supplies.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.