{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T16:45:35Z","timestamp":1787244335201,"version":"build-2736575974"},"reference-count":38,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T00:00:00Z","timestamp":1787184000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>Background: Hospital water systems are major environmental reservoirs of Pseudomonas aeruginosa, but evidence on the long-term impact of Water Safety Plans (WSPs) on environmental prevalence, antimicrobial resistance, and biofilm-forming ability remains limited. This study evaluated the long-term occurrence of P. aeruginosa in a hospital water distribution system over a 15-year surveillance period. Methods: A 15-year environmental surveillance study was conducted in a tertiary-care hospital in Northern Italy. Water samples were cultured for P. aeruginosa, and recovered isolates were assessed for antimicrobial susceptibility and biofilm-forming ability. Temporal trends were analysed using generalized linear and segmented logistic regression models. Results: Among 1696 water samples, the overall prevalence of P. aeruginosa was 2.93%, with a significant annual decline of 12% (OR 0.88, 95% CI 0.82\u20130.94; p &lt; 0.001). Segmented regression identified a marked reduction after the fourth year (OR 0.18, 95% CI 0.06\u20130.55; p = 0.003). Over time, isolates shifted toward weak or non-biofilm-producing phenotypes while maintaining high antimicrobial susceptibility, with only one multidrug-resistant isolate detected. Conclusions: Long-term surveillance integrated within a comprehensive WSP was associated with reduced P. aeruginosa contamination, decreased biofilm-forming ability, and persistently low antimicrobial resistance.<\/jats:p>","DOI":"10.3390\/pathogens15080868","type":"journal-article","created":{"date-parts":[[2026,8,20]],"date-time":"2026-08-20T09:48:31Z","timestamp":1787219311000},"page":"868","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Long-Term Environmental Surveillance of Pseudomonas aeruginosa in a Hospital Water Distribution System: Trends in Prevalence, Biofilm Formation, and Antimicrobial Susceptibility"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7926-7108","authenticated-orcid":false,"given":"Maria Luisa","family":"Cristina","sequence":"first","affiliation":[{"name":"Department of Health Sciences, University of Genoa, 16132 Genoa, Italy"},{"name":"Operating Unit Hospital Hygiene, Galliera Hospital, 16128 Genoa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-1999-8786","authenticated-orcid":false,"given":"Elisa","family":"Schinca","sequence":"additional","affiliation":[{"name":"Department of Health Sciences, University of Genoa, 16132 Genoa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-5868-5741","authenticated-orcid":false,"given":"Carolina","family":"Piccinini","sequence":"additional","affiliation":[{"name":"Department of Health Sciences, University of Genoa, 16132 Genoa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sara","family":"Cima","sequence":"additional","affiliation":[{"name":"Department of Health Sciences, University of Genoa, 16132 Genoa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-5542-4094","authenticated-orcid":false,"given":"Gianluca","family":"Ottria","sequence":"additional","affiliation":[{"name":"Department of Health Sciences, University of Genoa, 16132 Genoa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chiara","family":"Dupont","sequence":"additional","affiliation":[{"name":"Department of Health Sciences, University of Genoa, 16132 Genoa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0008-9907-3299","authenticated-orcid":false,"given":"Alessio","family":"Carbone","sequence":"additional","affiliation":[{"name":"Department of Medicine, Division of Medical Oncology, Galliera Hospital, 16128 Genoa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7127-2893","authenticated-orcid":false,"given":"Marina","family":"Sartini","sequence":"additional","affiliation":[{"name":"Department of Health Sciences, University of Genoa, 16132 Genoa, Italy"},{"name":"Operating Unit Hospital Hygiene, Galliera Hospital, 16128 Genoa, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1007\/s00203-026-04839-0","article-title":"Pseudomonas Aeruginosa: Associated Pathogenesis, Epidemiology, Resistance Mechanisms, Host Response and Emerging Treatment Strategies","volume":"208","author":"Sawant","year":"2026","journal-title":"Arch. 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