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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., Conclusion: 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., (Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.)

Noninvasive thyroid nodules that exhibit borderline morphological signs of papillary cancer are difficult to diagnose and we do not know if they represent papillary carcinoma precursor lesions. Forty-six such nodules were analyzed for RET activation by immunohistochemistry and, in selected cases, by reverse transcriptase-polymerase chain reaction performed on RNA extracted after laser capture microdissection (LCM) of the tumor foci with and without papillary carcinoma features and positive RET immunoreactivity. RET immunoreactivity was identified, at least focally, in 30 of 46 (65.2%) of the nodules where it closely paralleled the morphological changes. Enough RNA was obtained after LCM in seven samples. RET/PTC1 or RET/PTC3 were detected in microscopic foci with papillary carcinoma features in most of the thyroid nodules (five of seven cases). No RET/PTC1 or RET/PTC3 rearrangements were detected in areas of the same tumors that lacked the cytological alterations. Analysis of clonality in the same nodules selected for LCM demonstrated that two were monoclonal and six were polyclonal. We conclude that RET activation closely parallels the morphological changes, that it is restricted to those areas of the tumor with the cytological alterations and that it is detectable in both mono- and polyclonal tumors. Although the finding of microscopic foci indicative of papillary carcinoma in a hyperplastic or adenomatous nodule does not justify the interpretation of the entire lesion as papillary carcinoma, it is possible that such foci may precede the development of invasive papillary cancer.