{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T18:36:56Z","timestamp":1787683016302,"version":"build-2784847793"},"reference-count":38,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,2,17]],"date-time":"2026-02-17T00:00:00Z","timestamp":1771286400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"MUR PNRR Extended Partnership initiative on Emerging Infectious Diseases","award":["PE00000007, INF-ACT"],"award-info":[{"award-number":["PE00000007, INF-ACT"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>Legionella pneumophila (Lp) remains one of the major causes of community- and hospital-acquired pneumonia, yet its diagnosis and source attribution continue to pose significant challenges. Here, we describe the case of an immunocompromised patient who developed Legionnaires\u2019 disease during hospitalization. Following activation of the hospital\u2019s internal surveillance system, Lp and Legionella anisa (L. anisa) were recovered from multiple water distribution points using a simplified culture-based protocol. Whole-genome sequencing (WGS) demonstrated that all environmental isolates belonged to a single clonal strain, whereas the clinical isolate was genetically unrelated, thereby excluding the hospital water system as the source of infection. Although not implicated in the patient\u2019s disease, the detection of both Lp and L. anisa within the plumbing system highlighted underlying structural contamination and the potential masking effect of non-L. pneumophila species during culture-based surveillance. These findings support the integration of conventional microbiological methods with high-resolution genomic tools to enhance surveillance accuracy, support outbreak investigations, and strengthen public health responses. Overall, this case underscores the value of WGS as a decisive tool for source attribution, including the robust exclusion of a suspected nosocomial source, in complex clinical and environmental scenarios.<\/jats:p>","DOI":"10.3390\/microorganisms14020486","type":"journal-article","created":{"date-parts":[[2026,2,17]],"date-time":"2026-02-17T13:15:35Z","timestamp":1771334135000},"page":"486","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Role of Next-Generation Sequencing in Excluding the Nosocomial Origin of a Case of Legionnaires\u2019 Disease Integrating Environmental Surveillance and Clinical Diagnosis"],"prefix":"10.3390","volume":"14","author":[{"given":"Francesco","family":"Paglione","sequence":"first","affiliation":[{"name":"Department of Basic Biotechnological Sciences, Intensive and Perioperative Clinics, Universit\u00e0 Cattolica del Sacro Cuore, L.go F. Vito 1, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cataldo Maria","family":"Mannavola","sequence":"additional","affiliation":[{"name":"Department of Basic Biotechnological Sciences, Intensive and Perioperative Clinics, Universit\u00e0 Cattolica del Sacro Cuore, L.go F. Vito 1, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marilena","family":"La Sorda","sequence":"additional","affiliation":[{"name":"Department of Laboratory and Hematological Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS, L.go A. Gemelli 8, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria Luisa","family":"Ricci","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, Istituto Superiore di Sanit\u00e0, Viale Regina Elena 299, 00161 Rome, Italy"},{"name":"ESCMID Study Group for Legionella Infections (ESGLI), 4051 Basel, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria","family":"Scaturro","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, Istituto Superiore di Sanit\u00e0, Viale Regina Elena 299, 00161 Rome, Italy"},{"name":"ESCMID Study Group for Legionella Infections (ESGLI), 4051 Basel, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Silvia Laura","family":"Bosello","sequence":"additional","affiliation":[{"name":"Division of Rheumatology and Clinical Immunology, Fondazione Policlinico Universitario A. Gemelli, IRCCS, L.go A. Gemelli 8, 00168 Rome, Italy"},{"name":"Department of Geriatric and Orthopedic Sciences, Division of Rheumatology, Universit\u00e0 Cattolica del Sacro Cuore, L.go F, Vito 1, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Roberta","family":"Masnata","sequence":"additional","affiliation":[{"name":"Division of Rheumatology and Clinical Immunology, Fondazione Policlinico Universitario A. Gemelli, IRCCS, L.go A. Gemelli 8, 00168 Rome, Italy"},{"name":"Department of Geriatric and Orthopedic Sciences, Division of Rheumatology, Universit\u00e0 Cattolica del Sacro Cuore, L.go F, Vito 1, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Francesca Romana","family":"Monzo","sequence":"additional","affiliation":[{"name":"Department of Laboratory and Hematological Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS, L.go A. Gemelli 8, 00168 Rome, Italy"},{"name":"Microbiota Analysis & Microbial WGS Research Core Facility, GSTeP, Fondazione Policlinico Universitario A. Gemelli IRCCS, L.go A. Gemelli 8, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sara","family":"Vincenti","sequence":"additional","affiliation":[{"name":"Institute of Hygiene, Universit\u00e0 Cattolica del Sacro Cuore, Lgo F, Vito 1, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Patrizia","family":"Laurenti","sequence":"additional","affiliation":[{"name":"Institute of Hygiene, Universit\u00e0 Cattolica del Sacro Cuore, Lgo F, Vito 1, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9780-7059","authenticated-orcid":false,"given":"Maurizio","family":"Sanguinetti","sequence":"additional","affiliation":[{"name":"Department of Basic Biotechnological Sciences, Intensive and Perioperative Clinics, Universit\u00e0 Cattolica del Sacro Cuore, L.go F. Vito 1, 00168 Rome, Italy"},{"name":"Department of Laboratory and Hematological Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS, L.go A. Gemelli 8, 00168 Rome, Italy"},{"name":"Microbiota Analysis & Microbial WGS Research Core Facility, GSTeP, Fondazione Policlinico Universitario A. Gemelli IRCCS, L.go A. Gemelli 8, 00168 Rome, Italy"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4744-9820","authenticated-orcid":false,"given":"Flavio","family":"De Maio","sequence":"additional","affiliation":[{"name":"Department of Laboratory and Hematological Sciences, Fondazione Policlinico Universitario A. Gemelli IRCCS, L.go A. Gemelli 8, 00168 Rome, Italy"},{"name":"Microbiota Analysis & Microbial WGS Research Core Facility, GSTeP, Fondazione Policlinico Universitario A. Gemelli IRCCS, L.go A. 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Rev., 49.","DOI":"10.1093\/femsre\/fuaf022"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"376","DOI":"10.1016\/S0140-6736(15)60078-2","article-title":"Legionnaires\u2019 disease","volume":"387","author":"Cunha","year":"2016","journal-title":"Lancet"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1189","DOI":"10.1056\/NEJM197712012972201","article-title":"Legionnaires\u2019 disease: Description of an epidemic of pneumonia","volume":"297","author":"Fraser","year":"1977","journal-title":"N. Engl. J. Med."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"973","DOI":"10.1007\/s40121-022-00635-7","article-title":"Legionnaires\u2019 Disease: Update on Diagnosis and Treatment","volume":"11","author":"Viasus","year":"2022","journal-title":"Infect. Dis. Ther."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"439","DOI":"10.1146\/annurev-pathmechdis-012419-032742","article-title":"Legionnaires\u2019 Disease: State of the Art Knowledge of Pathogenesis Mechanisms of Legionella","volume":"15","author":"Mondino","year":"2020","journal-title":"Annu. Rev. Pathol. Mech. Dis."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"42","DOI":"10.1016\/j.ijid.2020.10.106","article-title":"Evaluation of a novel urinary antigen test kit for diagnosing Legionella pneumonia","volume":"103","author":"Ito","year":"2021","journal-title":"Int. J. Infect. Dis."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"56","DOI":"10.1016\/j.resinv.2021.09.009","article-title":"Atypical pneumonia: Pathophysiology, diagnosis, and treatment","volume":"60","author":"Miyashita","year":"2022","journal-title":"Respir. Investig."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Gattuso, G., Rizzo, R., Lavoro, A., Spoto, V., Porciello, G., Montagnese, C., Cin\u00e0, D., Cosentino, A., Lombardo, C., and Mezzatesta, M.L. (2022). Overview of the Clinical and Molecular Features of Legionella pneumophila: Focus on Novel Surveillance and Diagnostic Strategies. Antibiotics, 11.","DOI":"10.3390\/antibiotics11030370"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"2135","DOI":"10.1128\/JCM.00432-16","article-title":"Evaluation of an optimal epidemiological typing scheme for Legionella pneumophila with whole-genome sequence data using validation guidelines","volume":"54","author":"David","year":"2016","journal-title":"J. Clin. Microbiol."},{"key":"ref_11","unstructured":"The European Parliament (2020). Directive (Eu) 2020\/2184 of the European Parliament and of the Council of 16 December 2020 on the Quality of Water Intended for Human Consumption, The European Parliament."},{"key":"ref_12","unstructured":"Ministero della Salute (2015). Linee Guida per la Prevenzione ed il Controllo Della Legionellosis, Ministero della Salute."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Vincenti, S., Nurchis, M.C., Boninti, F., Sapienza, M., Raponi, M., Pattavina, F., Pesaro, C., D\u2019alonzo, C., Damiani, G., and Laurenti, P. (2025). An Innovative Device for the Hot Water Circuit in Hospitals to Save Energy Without Compromising the Safety and Quality of Water: Preliminary Results. Water, 17.","DOI":"10.3390\/w17050692"},{"key":"ref_14","unstructured":"(2017). Water Quality\u2014Enumeration of Legionella (Standard No. ISO 11731:2017)."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"710","DOI":"10.1007\/s10096-002-0820-3","article-title":"Pan-European study on culture-proven Legionnaires\u2019 disease: Distribution of Legionella pneumophila serogroups and monoclonal subgroups","volume":"21","author":"Helbig","year":"2002","journal-title":"Eur. J. Clin. Microbiol. Infect. Dis."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2047","DOI":"10.1128\/JCM.43.5.2047-2052.2005","article-title":"Consensus sequence-based scheme for epidemiological typing of clinical and environmental isolates of Legionella pneumophila","volume":"43","author":"Gaia","year":"2005","journal-title":"J. Clin. Microbiol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1965","DOI":"10.1128\/JCM.00261-07","article-title":"Addition of neuA, the gene encoding N-acylneuraminate cytidylyl transferase, increases the discriminatory ability of the consensus sequence-based scheme for typing Legionella pneumophila serogroup 1 strains","volume":"45","author":"Ratzow","year":"2007","journal-title":"J. Clin. Microbiol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1549","DOI":"10.1128\/JCM.01794-09","article-title":"Performance of matrix-assisted laser desorption ionization-time of flight mass spectrometry for identification of bacterial strains routinely isolated in a Clinical Microbiology Laboratory","volume":"48","author":"Bizzini","year":"2010","journal-title":"J. Clin. Microbiol."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Sali, M., De Maio, F., Tarantino, M., Garofolo, G., Tittarelli, M., Sacchini, L., Zilli, K., Pasquali, P., Petrucci, P., and Marianelli, C. (2018). Rapid and safe one-step extraction method for the identification of Brucella strains at genus and species level by MALDI-TOF mass spectrometry. PLoS ONE, 13.","DOI":"10.1371\/journal.pone.0197864"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"De Maio, F., Rosato, R., La Sorda, M., Gatto, A., Santarelli, G., Di Sarno, L., Fiori, B., Posteraro, B., Chiaretti, A., and Sanguinetti, M. (2025). Elucidating the role of group A Streptococcus genomics and pharyngeal microbiota in acute paediatric pharyngitis. Sci. Rep., 15.","DOI":"10.1038\/s41598-025-19099-z"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"De Maio, F., Bianco, D.M., Santarelli, G., Rosato, R., Monzo, F.R., Fiori, B., Sanguinetti, M., and Posteraro, B. (2025). Profiling the gut microbiota to assess infection risk in Klebsiella pneumoniae-colonized patients. Gut Microbes, 17.","DOI":"10.1080\/19490976.2025.2468358"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Mannavola, C.M., De Maio, F., Marra, J., Fiori, B., Santarelli, G., Posteraro, B., Sica, S., D\u2019iNzeo, T., and Sanguinetti, M. (2025). Bloodstream infection by Lactobacillus rhamnosus in a haematology patient: Why metagenomics can make the difference. Gut Pathog., 17.","DOI":"10.1186\/s13099-025-00722-3"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Garcill\u00e1n-Barcia, M.P., Redondo-Salvo, S., Vielva, L., and de la Cruz, F. (2020). MOBscan: Automated Annotation of MOB Relaxases. Methods in Molecular Biology, Springer.","DOI":"10.1007\/978-1-4939-9877-7_21"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"W443","DOI":"10.1093\/nar\/gkad382","article-title":"PHASTEST: Faster than PHASTER, better than PHAST","volume":"51","author":"Wishart","year":"2023","journal-title":"Nucleic Acids Res."},{"key":"ref_25","unstructured":"GitHub (2020). Tseemann\/legsta. Silico Legionella pneumophila Sequence Based Typing, GitHub."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"294","DOI":"10.1038\/nbt.2522","article-title":"Updating benchtop sequencing performance comparison","volume":"31","author":"Sedlazeck","year":"2013","journal-title":"Nat. Biotechnol."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Moran-Gilad, J., Prior, K., Yakunin, E., Harrison, T.G., Underwood, A., Lazarovitch, T., Valinsky, L., L\u00fcck, C., Krux, F., and Agmon, V. (2015). Design and application of a core genome multilocus sequence typing scheme for investigation of Legionnaires\u2019 disease incidents. Eurosurveillance, 20.","DOI":"10.2807\/1560-7917.ES2015.20.28.21186"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"181","DOI":"10.1016\/j.jgar.2024.12.030","article-title":"Antimicrobial susceptibility and epidemiological types of Legionella pneumophila human isolates from Italy (1987\u20132020)","volume":"41","author":"Scaturro","year":"2025","journal-title":"J. Glob. Antimicrob. Resist."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Moffa, M.A., Rock, C., Galiatsatos, P., Gamage, S.D., Schwab, K.J., and Exum, N.G. (2023). Legionellosis on the rise: A scoping review of sporadic, community-acquired incidence in the United States. Epidemiol. Infect., 151.","DOI":"10.1017\/S0950268823001206"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Toplitsch, D., Platzer, S., Zehner, R., Maitz, S., Mascher, F., and Kittinger, C. (2021). Comparison of updated methods for Legionella detection in environmental water samples. Int. J. Environ. Res. Public Health, 18.","DOI":"10.3390\/ijerph18105436"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"La Sorda, M., Palucci, I., Natalini, D., Fillo, S., Giordani, F., Paglione, F., Monte, A., Lista, F., Mancini, F., and Girolamo, A. (2024). Case report: First report of Legionella pneumophila and Bordetella bronchiseptica coinfection in an immunocompromised patient. Front. Med., 11.","DOI":"10.3389\/fmed.2024.1470567"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"D\u00f6rrie, B., and Nogueira, R. (2024). Lessons learned from a one-year study of Legionella spp. cultivation from activated sludge samples. J. Environ. Manag., 369.","DOI":"10.1016\/j.jenvman.2024.122266"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Ducret, A., Chabalier, M., and Dukan, S. (2014). Characterization and resuscitation of \u2018non-culturable\u2019 cells of Legionella pneumophila. BMC Microbiol., 14.","DOI":"10.1186\/1471-2180-14-3"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Whiley, H. (2017). Legionella risk management and control in potable water systems: Argument for the abolishment of routine testing. Int. J. Environ. Res. Public Health, 14.","DOI":"10.3390\/ijerph14010012"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"879","DOI":"10.1111\/j.1469-0691.2007.01756.x","article-title":"Comparison of broad-range bacterial PCR and culture of cerebrospinal fluid for diagnosis of community-acquired bacterial meningitis","volume":"13","author":"Dotevall","year":"2007","journal-title":"Clin. Microbiol. Infect."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Gleason, J.A., and Cohn, P.D. (2022). A review of legionnaires\u2019 disease and public water systems\u2014Scientific considerations, uncertainties and recommendations. Int. J. Hyg. Environ. Health, 240.","DOI":"10.1016\/j.ijheh.2021.113906"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Reuter, S., Harrison, T.G., K\u00f6ser, C.U., Ellington, M.J., Smith, G.P., Parkhill, J., Peacock, S.J., Bentley, S.D., and T\u00f6r\u00f6k, M.E. (2013). A pilot study of rapid whole-genome sequencing for the investigation of a Legionella outbreak. BMJ Open, 3.","DOI":"10.1136\/bmjopen-2012-002175"},{"key":"ref_38","unstructured":"Istituto Superiore di Sanit\u00e0 (2025). Legionellosi\u2014EpiCentro\u2014Istituto Superiore di Sanit\u00e0, Istituto Superiore di Sanit\u00e0."}],"container-title":["Microorganisms"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-2607\/14\/2\/486\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,17]],"date-time":"2026-02-17T13:24:12Z","timestamp":1771334652000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-2607\/14\/2\/486"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2,17]]},"references-count":38,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,2]]}},"alternative-id":["microorganisms14020486"],"URL":"https:\/\/doi.org\/10.3390\/microorganisms14020486","relation":{},"ISSN":["2076-2607"],"issn-type":[{"value":"2076-2607","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2,17]]}}}