{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,14]],"date-time":"2026-08-14T11:31:14Z","timestamp":1786707074922,"version":"build-2736575974"},"reference-count":41,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,8,14]],"date-time":"2026-08-14T00:00:00Z","timestamp":1786665600000},"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>Legionella pneumophila (L. pneumophila) persists in engineered water systems and is the causative agent of Legionnaires\u2019 disease. Despite its clinical importance, little is known about whether environmental populations are undergoing gradual changes in their antimicrobial susceptibility. Here, we compared the antimicrobial susceptibility of 95 environmental L. pneumophila isolates collected in 2013\u20132014 with those obtained in 2024\u20132025 from the same sites in a drinking water distribution system (DWDS) using Epsilometer (E-test). The analyses showed both temporal and spatial variation: Ciprofloxacin activity remained relatively stable, whereas levofloxacin exhibited a broader minimum inhibitory concentration (MIC) range among contemporary isolates, with the minimum inhibitory concentration required to inhibit the growth of 90% of isolates (MIC90) doubling from 0.5 to 1.0 mg\/L, suggesting increased variability and the emergence of less susceptible subpopulations. Tigecycline showed a marked site-specific increase in MIC values, with the mean MIC at site D increasing from 0.26 mg\/L in the 2013\u20132014 isolates to 1.86 mg\/L in the 2024\u20132025 isolates, indicating reduced susceptibility at this site. Among macrolides, erythromycin exhibited the lowest MIC values across both isolate collections, whereas azithromycin showed higher MIC values. Moreover, isolates recovered from adjacent sites within the same DWDS exhibited significantly different susceptibility profiles, possibly reflecting the influence of local environmental conditions. These findings emphasize that L. pneumophila susceptibility is not static but is likely shaped by ecological and temporal factors. The study underscores the importance of long-term environmental surveillance to track the evolution of this pathogen and provides new insights into how micro-scale dynamics within water systems can influence antimicrobial susceptibility patterns.<\/jats:p>","DOI":"10.3390\/pathogens15080852","type":"journal-article","created":{"date-parts":[[2026,8,14]],"date-time":"2026-08-14T10:39:01Z","timestamp":1786703941000},"page":"852","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Longitudinal Antimicrobial Susceptibility Shifts in Environmental Legionella pneumophila from a Drinking Water Distribution System"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-6087-5616","authenticated-orcid":false,"given":"Lana","family":"Madagi","sequence":"first","affiliation":[{"name":"Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maya","family":"Azrad","sequence":"additional","affiliation":[{"name":"Clinical Microbiology Laboratory, Tzafon Medical Center, Poriya 1528001, Israel"},{"name":"Azrieli Faculty of Medicine, Bar Ilan University, Safed 1311502, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-7043-3382","authenticated-orcid":false,"given":"May","family":"Karp","sequence":"additional","affiliation":[{"name":"Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Avi","family":"Peretz","sequence":"additional","affiliation":[{"name":"Clinical Microbiology Laboratory, Tzafon Medical Center, Poriya 1528001, Israel"},{"name":"Azrieli Faculty of Medicine, Bar Ilan University, Safed 1311502, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1936-431X","authenticated-orcid":false,"given":"Yehonatan","family":"Sharaby","sequence":"additional","affiliation":[{"name":"Department of Evolutionary and Environmental Biology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel"},{"name":"Department of Biology and Environment, Oranim College, Kiryat Tivon 3600600, Israel"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1011","DOI":"10.1016\/S1473-3099(14)70713-3","article-title":"Epidemiology and Clinical Management of Legionnaires\u2019 Disease","volume":"14","author":"Phin","year":"2014","journal-title":"Lancet Infect. 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