Evaluation of Legionella Air Contamination in Healthcare Facilities by Different Sampling Methods: An Italian Multicenter Study
نویسندگان
چکیده
Healthcare facilities (HF) represent an at-risk environment for legionellosis transmission occurring after inhalation of contaminated aerosols. In general, the control of water is preferred to that of air because, to date, there are no standardized sampling protocols. Legionella air contamination was investigated in the bathrooms of 11 HF by active sampling (Surface Air System and Coriolis®μ) and passive sampling using settling plates. During the 8-hour sampling, hot tap water was sampled three times. All air samples were evaluated using culture-based methods, whereas liquid samples collected using the Coriolis®μ were also analyzed by real-time PCR. Legionella presence in the air and water was then compared by sequence-based typing (SBT) methods. Air contamination was found in four HF (36.4%) by at least one of the culturable methods. The culturable investigation by Coriolis®μ did not yield Legionella in any enrolled HF. However, molecular investigation using Coriolis®μ resulted in eight HF testing positive for Legionella in the air. Comparison of Legionella air and water contamination indicated that Legionella water concentration could be predictive of its presence in the air. Furthermore, a molecular study of 12 L. pneumophila strains confirmed a match between the Legionella strains from air and water samples by SBT for three out of four HF that tested positive for Legionella by at least one of the culturable methods. Overall, our study shows that Legionella air detection cannot replace water sampling because the absence of microorganisms from the air does not necessarily represent their absence from water; nevertheless, air sampling may provide useful information for risk assessment. The liquid impingement technique appears to have the greatest capacity for collecting airborne Legionella if combined with molecular investigations.
منابع مشابه
Response to Comments on Montagna et al. “Evaluation of Legionella Air Contamination in Healthcare Facilities by Different Sampling Methods: An Italian Multicenter Study” Int. J. Environ. Res. Public Health 2017, 14, 670
We would like to thank Collins andWalker for their comments and for acknowledging that this is an area requiring more research to improve our basic understanding of Legionella [1]. [...].
متن کاملComment on Montagna, et al. Evaluation of Legionella air contamination in healthcare facilities by different sampling methods: An Italian multicenter study. Int. J. Environ. Res. Public Health 2017, 14, 670
In their recent article, Montagna et al. describe a multicenter study investigating the presence of Legionella in water and air samples of Italian healthcare facilities [1]. This is an interesting study that highlights some important gaps in our basic understanding of Legionella. One of the limitations of the study regarded the lack of information on the tap outlets (e.g., design of tap, flow r...
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