title: Effect of temperature and colonization of Legionella pneumophila and Vermamoeba vermiformis on bacterial community composition of copper drinking water biofilms.
abstract: It is unclear how the water-based pathogen, Legionella pneumophila (Lp), and associated free-living amoeba (FLA) hosts change or are changed by the microbial composition of drinking water (DW) biofilm communities. Thus, this study characterized the bacterial community structure over a 7-month period within mature (> 600-day-old) copper DW biofilms in reactors simulating premise plumbing and assessed the impact of temperature and introduction of Lp and its FLA host, Vermamoeba vermiformis (Vv), co-cultures (LpVv). Sequence and quantitative PCR (qPCR) analyses indicated a correlation between LpVv introduction and increases in Legionella spp. levels at room temperature (RT), while at 37°C, Lp became the dominant Legionella spp. qPCR analysis suggested Vv presence may not be directly associated with Lp biofilm growth at RT and 37°C, but may contribute to or be associated with non-Lp legionellae persistence at RT. Two-way PERMANOVA and PCoA revealed that temperature was a major driver of microbiome diversity. Biofilm community composition also changed over the seven-month period and could be associated with significant shifts in dissolved oxygen, alkalinity and various metals in the influent DW. Hence, temperature, biofilm age, DW quality and transient intrusions/amplification of pathogens and FLA hosts may significantly impact biofilm microbiomes and modulate pathogen levels over extended periods.
authors.affiliation: Pegasus Technical Services, Inc c/o US EPA, 26 W Martin Luther King Drive NG-16, Cincinnati, OH, 45268, USA.
authors.forename: Helen Y
authors.initials: HY
authors.lastname: Buse
authors.affiliation: Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA.
authors.forename: Pan
authors.initials: P
authors.lastname: Ji
authors.affiliation: Pegasus Technical Services, Inc c/o US EPA, 26 W Martin Luther King Drive NG-16, Cincinnati, OH, 45268, USA.
authors.forename: Vicente
authors.initials: V
authors.lastname: Gomez-Alvarez
authors.affiliation: Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA.
authors.forename: Amy
authors.initials: A
authors.lastname: Pruden
authors.affiliation: Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, USA.
authors.forename: Marc A
authors.initials: MA
authors.lastname: Edwards
authors.affiliation: School of Public Health, University of Alberta, Edmonton, AB T6G 2G7, Canada.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Ashbolt
mesh_terms: D018441:Biofilms / Q000254:growth & development*; D058448:Biota; D003300:Copper; D060766:Drinking Water / Q000737:chemistry / Q000382:microbiology* / Q000469:parasitology*; D016952:Legionella pneumophila / Q000254:growth & development*; D016840:Lobosea / Q000254:growth & development* / Q000382:microbiology; D060888:Real-Time Polymerase Chain Reaction; D013696:Temperature; D014131:Trace Elements
chemical_list: D060766:Drinking Water; D014131:Trace Elements; D003300:Copper