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Widespread molecular detection of Legionella pneumophila Serogroup 1 in cold water taps across the United States
Citation:
Donohue, M., K. O’Connell, S. Vesper, J. Mistry, D. King, M. Kostich, AND S. Pfaller. Widespread molecular detection of Legionella pneumophila Serogroup 1 in cold water taps across the United States. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, 48(6):3145-3152, (2014).
Impact/Purpose:
This is a basic research project which may provide valuable information regarding microorganisms identified on the 1998 CCL (and future CCLs) or other important microbiological contaminants in drinking water. Sensitive and rapid methods, as well as occurrence data, are needed for a number of microorganisms listed on the 1998 CCL. The type of data generated from this research can provide microbiologists with information regarding specific proteins contained within infective/viable microorganisms and these identified proteins can then be used to develop rapid, sensitive methods for microorganisms in drinking water. This will be a collaborative basic effort with NERL/MCEARD microbiologists and chemists and the results of our combined efforts will periodically be presented to EPA's Office of Ground Water and Drinking Water (OGWDW). Any unique markers of microbial exposure characterized by these mass spectrometric techniques can then be used to develop a sensitive method(s) for microbes identified on the 1998 CCL and any future CCLs. Thus, this project will provide information needed to develop better microbial methods. These microbial methods will gather occurrence data which will provide critical information to be used in creating better EPA regulations and policies for protecting humans from CCL microorganisms in U.S. drinking water supplies. The PI(s) will establish contacts in the scientific community through attendance/presentation at national conferences as well as through correspondence with researchers that have similar interest.
Description:
In the United States 3,522 cases of legionellosis were reported to the Center for Disease Control and Prevention in 2009. Of these reports, it is estimated that 84% are caused by the microorganism Legionella pneumophila Serogroup (Sg) 1. Legionella spp. have been isolated and recovered from a variety of natural freshwater environments. Human exposure to L. pneumophila Sg1 occurs from public potable water systems. In this study, two primer/probe sets (one able to detect L. pneumophila and the other L. pneumophila Sg1) were determined to be highly sensitivity and selective to their respective targets. These qPCR assays were then used to evaluate the incidence and persistence of L. pneumophila Sg1 in samples collected at public water taps across the United States. Over 274 drinking water samples were collected in 2009 and 2010 from 69 taps were evaluated using two qPCR assays. Of the drinking water taps monitored 49% were positive for both assays at least once and 16% of taps showed persistence of both gene products. The two most popular disinfectants use to control microbes demonstrates some impact on persistence and average concentration (genomic target/L) of L. pneumophila Sg1. Chloramine was effective at lowering the concentration /L and reducing persistence of L. pneumophila Sg1 at taps. However, incidence of L. pneumophila Sg1 in chloramine treated water was similar to chlorine treated water.
