title: Opportunistic pathogens in roof-captured rainwater samples, determined using quantitative PCR.
abstract: In this study, quantitative PCR (qPCR) was used for the detection of four opportunistic bacterial pathogens in water samples collected from 72 rainwater tanks in Southeast Queensland, Australia. Tank water samples were also tested for fecal indicator bacteria (Escherichia coli and Enterococcus spp.) using culture-based methods. Among the 72 tank water samples tested, 74% and 94% samples contained E. coli and Enterococcus spp., respectively, and the numbers of E. coli and Enterococcus spp. in tank water samples ranged from 0.3 to 3.7 log₁₀ colony forming units (CFU) per 100 mL of water. In all, 29%, 15%, 13%, and 6% of tank water samples contained Aeromonas hydrophila, Staphylococcus aureus, Pseudomonas aeruginosa and Legionella pneumophila, respectively. The genomic units (GU) of opportunistic pathogens in tank water samples ranged from 1.5 to 4.6 log₁₀ GU per 100 mL of water. A significant correlation was found between E. coli and Enterococcus spp. numbers in pooled tank water samples data (Spearman's rs = 0.50; P < 0.001). In contrast, fecal indicator bacteria numbers did not correlate with the presence/absence of opportunistic pathogens tested in this study. Based on the results of this study, it would be prudent, to undertake a Quantitative Microbial Risk Assessment (QMRA) analysis of opportunistic pathogens to determine associated health risks for potable and nonpotable uses of tank water.
authors: CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Brisbane 4102, Australia. Electronic address: Warish.Ahmed@csiro.au.
authors: W
authors: W
authors: Ahmed
authors: CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Brisbane 4102, Australia; Environmental Studies Department, University of Colorado, Boulder, CO 80309-0397, USA.
authors: H
authors: H
authors: Brandes
authors: CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Brisbane 4102, Australia; School of Population Health, University of Queensland, Herston Road, Brisbane 4006, Australia.
authors: P
authors: P
authors: Gyawali
authors: CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Brisbane 4102, Australia.
authors: J P S
authors: JP
authors: Sidhu
authors: CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Brisbane 4102, Australia; School of Population Health, University of Queensland, Herston Road, Brisbane 4006, Australia.
authors: S
authors: S
authors: Toze
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification*; D001426:Bacterial Proteins / Q000235:genetics; D015169:Colony Count, Microbial; D004784:Environmental Monitoring; D005243:Feces / Q000382:microbiology*; D010865:Pilot Projects; D011793:Queensland; D011891:Rain / Q000382:microbiology*; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D001426:Bacterial Proteins
keywords: Fecal indicator bacteria; Health risks; Opportunistic pathogens; Quantitative PCR; Roof-captured rainwater