Citation:

Hoelle, J., M. Coughlin, E. Sotkiewicz, J. Lu, S. Pfaller, M. Rodgers, AND H. Ryu. Occurrence of Opportunistic Pathogens Legionella Pneumophilaand Non-tuberculous Mycobacteria in Hospital Plumbing Systems. To be Presented at ASM-Microbe, Boston, MA, June 16 - 20, 2016.

Impact/Purpose:

Poster prepared for presentation at the American Society of Microbiologists annual meeting being held in Boston, MA from June 16-20.

Description:

Opportunistic premise plumbing pathogens (OPPPs) such as Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa are frequently detected in the plumbing systems of large buildings. The ability of these organisms to form biofilms and to grow in phagocytic amoeba are thought to provide some insulation from chlorine and other conventional water disinfectants. Copper-silver (Cu-Ag) ionization is one water treatment technology used in many hospital water systems as an additional barrier to the growth of waterborne pathogens. In this study, we investigated the occurrence of three OPPPs and phagocytic amoebae and the efficacy of Cu-Ag ionization in hospital plumbing systems in several buildings from one city. A total of 197 water and 31 swab samples were collected from 14 buildings, including two installed with Cu-Ag ionization. The samples were analyzed for Legionella by culture and L. pneumophila, nontuberculous mycobacteria (NTM) (M. avium and M. intracellulare), Pseudomonas aeruginosa, and two amoeba (Acanthamoeba and Vermamoeba vermiformis) by qPCR. Of the 166 water samples from facilities without Cu-Ag ionization, L. pneumophila were the most prevalent pathogen detected by qPCR (44%, 73/166), followed by V. vermiformis (13%), NTM (11%), and P. aeruginosa (6%). Of Legionella positive samples, 35 and 25 were confirmed as L. pneumophila serotype 1 by culture and qPCR, respectively. Overall, OPPPs were more prevalent in warm water with low chlorine residuals than in cold water with higher chlorine residuals. In the two facilities using Cu-Ag ionization, the prevalence of Legionella in the water was low (3%, 1/31), whereas Mycobacterium avium was detected at a high frequency (61%, 19/31) by qPCR. In addition to water, six of 26 swab samples were positive by qPCR for L. pneumophila including four serotype 1 positives, whereas M. avium was detected in one of five swabs from Cu-Ag ionization facilities. The other target microorganisms were not detected in any swab samples. Our observations that Cu-Ag ionization may control Legionella but enhance colonization of pathogenic mycobacteria in building plumbing systems should encourage further studies on the reduction in risks from waterborne pathogens afforded by new treatment technologies.

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