title: Seasonal Assessment of Opportunistic Premise Plumbing Pathogens in Roof-Harvested Rainwater Tanks.
abstract: A seasonal study on the occurrence of six opportunistic premise plumbing pathogens (OPPPs) in 24 roof-harvested rainwater (RHRW) tanks repeatedly sampled over six monthly sampling events (n = 144) from August 2015 to March 2016 was conducted using quantitative qPCR. Fecal indicator bacteria (FIB) Escherichia coli (E. coli) and Enterococcus spp. were enumerated using culture-based methods. All tank water samples over the six events were positive for at least one OPPP (Legionella spp., Legionella pneumophila, Mycobacterium avium, Mycobacterium intracellulare, Pseudmonas aeruginosa, or Acanthamoeba spp.) during the entire course of the study. FIB were positively but weakly correlated with P. aeruginosa (E. coli vs P. aeruginosa τ = 0.090, p = 0.027; Enterococcus spp. vs P. aeruginosa τ = 0.126, p = 0.002), but not the other OPPPs. FIBs were more prevalent during the wet season than the dry season, and L. pneumophila was only observed during the wet season. However, concentrations of Legionella spp., M. intracellulare, Acanthamoeba spp., and M. avium peaked during the dry season. Correlations were assessed between FIB and OPPPs with meteorological variables, and it was determined that P. aeruginosa was the only OPPP positively associated with an increased antecedent dry period, suggesting stagnation time may play a role for the occurrence of this OPPP in tank water. Infection risks may exceed commonly cited benchmarks for uses reported in the rainwater usage survey such as pool top-up, and warrant further exploration through quantitative microbial risk assessment (QMRA).
authors.affiliation: CSIRO Land and Water , Ecosciences Precinct, 41 Boggo Road, Dutton Park, Queensland 4102, Australia.|Drexel University , 3141 Chestnut Street, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Kerry A
authors.identifier: 0000-0003-2991-7325
authors.initials: KA
authors.lastname: Hamilton
authors.affiliation: CSIRO Land and Water , Ecosciences Precinct, 41 Boggo Road, Dutton Park, Queensland 4102, Australia.
authors.forename: Warish
authors.initials: W
authors.lastname: Ahmed
authors.affiliation: CSIRO Land and Water , Ecosciences Precinct, 41 Boggo Road, Dutton Park, Queensland 4102, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Palmer
authors.affiliation: CSIRO Land and Water , Ecosciences Precinct, 41 Boggo Road, Dutton Park, Queensland 4102, Australia.
authors.forename: Kylie
authors.initials: K
authors.lastname: Smith
authors.affiliation: CSIRO Land and Water , Ecosciences Precinct, 41 Boggo Road, Dutton Park, Queensland 4102, Australia.
authors.forename: Simon
authors.initials: S
authors.lastname: Toze
authors.affiliation: Drexel University , 3141 Chestnut Street, Philadelphia, Pennsylvania 19104, United States.
authors.forename: Charles N
authors.initials: CN
authors.lastname: Haas
mesh_terms: D004926:Escherichia coli; D007875:Legionella; D016952:Legionella pneumophila; D012498:Sanitary Engineering; D012621:Seasons; D014871:Water Microbiology