title: Serological and molecular identification of Legionella spp. isolated from water and surrounding air samples in Italian healthcare facilities.
abstract: BACKGROUND
  Legionella is an intracellular microorganism living in natural and artificial aquatic environments. Although its transmission to humans is linked to the inhalation of contaminated aerosols, there is no validated air sampling method for the control and prevention of the disease. The aim of the present study was to provide more information on the distribution of Legionella spp. in indoor environments and to determine whether the same Legionella strains are isolated from air and water samples.
  
  
  METHODS
  Ten healthcare facilities located in seven regions of Italy were enrolled. The serological typing of Legionella spp. from water samples and the surrounding air by active and passive sampling was assessed using polyvalent and monovalent antisera. Subsequently, the strains identified as Legionella pneumophila (Lpn) underwent molecular typing by sequence-based typing (SBT) using seven genes (flaA, pilE, asd, mip, mompS, proA, and neuA). The allelic profile number was assigned using the European Working Group for Legionella Infections-SBT database.
  
  
  RESULTS
  Lpn serogroup 6 was the most prevalent serogroup; it was found simultaneously in the air and water samples of three different healthcare facilities. In the remaining seven hospitals, Lpn serogroups 1, 6, 7, 9, and 12 were isolated exclusively from water samples. The molecular investigation showed that Lpn strains in the water and air samples of each positive healthcare facility had the same allelic profile. Strains, identified as sequence types (STs) 728 and ST 1638+ST 1324, were isolated in two respective healthcare facilities, and a new strain, identified as ST 1989, was obtained in one healthcare facility.
  
  
  CONCLUSIONS
  The application of the SBT method allowed to verify the homology among Legionella strains from water samples and the surrounding air. The results showed that the same Lpn strains were present in the air and water samples, and a new Legionella strain was identified.
authors.affiliation: Department of Biomedical Science and Human Oncology - Hygiene Section, University of Bari, Bari, Italy. Electronic address: mariateresa.montagna@uniba.it.
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Montagna
authors.affiliation: Department of Health Sciences, University of Genoa, Genoa, Italy.
authors.forename: Maria Luisa
authors.initials: ML
authors.lastname: Cristina
authors.affiliation: Department of Biomedical Science and Human Oncology - Hygiene Section, University of Bari, Bari, Italy.
authors.forename: Osvalda
authors.initials: O
authors.lastname: De Giglio
authors.affiliation: Department of Health Sciences, University of Genoa, Genoa, Italy.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: Spagnolo
authors.affiliation: Department of Biomedical Science and Human Oncology - Hygiene Section, University of Bari, Bari, Italy.
authors.forename: Christian
authors.initials: C
authors.lastname: Napoli
authors.affiliation: Department of Sciences for Health Promotion - Hygiene Section, University of Palermo, Palermo, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Cannova
authors.affiliation: Department of Biomedical Science - Hygiene Section, University of Sassari, Sassari, Italy.
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Deriu
authors.affiliation: Department of Biomedical Science and Morphological and Functional Images, University of Messina, Messina, Italy.
authors.forename: Santi Antonino
authors.initials: SA
authors.lastname: Delia
authors.affiliation: Department of Prevention Services of Hygiene and Public Health, ASL Salerno, Salerno, Italy.
authors.forename: Ada
authors.initials: A
authors.lastname: Giuliano
authors.affiliation: Department of Biology, University of Napoli "Federico II", Napoli, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Guida
authors.affiliation: Department of Biomedical Science and Morphological and Functional Images, University of Messina, Messina, Italy.
authors.forename: Pasqualina
authors.initials: P
authors.lastname: Laganà
authors.affiliation: Department of Movement and Health Sciences, University "Parthenope", Napoli, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Liguori
authors.affiliation: Department of Biomedical Science - Hygiene Section, University of Sassari, Sassari, Italy.
authors.forename: Ida
authors.initials: I
authors.lastname: Mura
authors.affiliation: Department of Public Health, University of Napoli, Napoli, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Pennino
authors.affiliation: IRCCS Fondazione Santa Lucia, Rome, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Rossini
authors.affiliation: Department of Public Health and Community Medicine, University of Verona, Verona, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Tardivo
authors.affiliation: Department of Public Health, University of Napoli, Napoli, Italy.
authors.forename: Ida
authors.initials: I
authors.lastname: Torre
authors.affiliation: Department of Sciences for Health Promotion - Hygiene Section, University of Palermo, Palermo, Italy.
authors.forename: Maria Valeria
authors.initials: MV
authors.lastname: Torregrossa
authors.affiliation: Unit "Control Hospital Hygiene" University Hospital Policlinico "P. Giaccone", Palermo, Italy.
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Villafrate
authors.affiliation: Department of Clinical and Experimental Medicine, University of Parma, U.O. Medical Immunology, University Hospital of Parma, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Albertini
authors.affiliation: Department of Biomedical, Biotechnological and Translation Sciences, University of Parma, Parma, Italy.
authors.forename: Cesira
authors.initials: C
authors.lastname: Pasquarella
mesh_terms: D000391:Air Microbiology; D001426:Bacterial Proteins / Q000235:genetics; D015169:Colony Count, Microbial; D060766:Drinking Water / Q000382:microbiology*; D006268:Health Facilities; D007558:Italy; D016952:Legionella pneumophila / Q000235:genetics / Q000302:isolation & purification*; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins; D060766:Drinking Water
keywords: Bioaerosol; Legionella; Molecular investigation; Serological typing