Strain diversity and spatiotemporal variation in the occurrence of Legionella spp. within a large building water system
Citation:
Buse, H., B. Morris, J. Szabo, AND J. Hall. Strain diversity and spatiotemporal variation in the occurrence of Legionella spp. within a large building water system. Legionella Conference 2019, Los Angeles,CA, September 11 - 13, 2019.
Impact/Purpose:
This poster highlights EPA work on opportunistic pathogens in building water systems and will be presented at an international conference...This study aimed to determine (1) the distribution of Legionella, free-living amoeba, mycobacteria within a large BWS over 28 months and (2) if their detection correlated with the presence of other microbes, water quality, or engineering parameters.
Description:
Understanding the survival mechanisms of Legionella within building water systems (BWSs) is challenging due to varying engineering, operational, and water quality characteristics unique to each system. Disinfectant residual and detection of the amoeba hosts, Acanthamoeba spp. and Vermamoeba vermiformis, did not correlate with culturable Legionella. In contrast, detection of Mycobacterium intracellularae and M. chimera were negatively correlated with Legionella culturability. The genomes of 21 L. pneumophila sg1, sg2-14, and non-pneumophila strains, isolated from four locations across three sampling events, were sequenced. Collectively, results indicated the presence of a diverse population of Legionella within this BWS with culturability being more dependent on water age, absence of mycobacteria, and plumbing material than the other measured parameters. Understanding how BWS characteristics influence Legionella survival may elucidate ways to minimize and prevent their growth within these systems.