Overall, 26% of Australian households use rainwater tanks as a source of potable and nonpotable water. Limited information is available on the total bacterial communities in tank water. Therefore, identification of dominant bacterial communities, diversity, and their distribution is important in understanding the microbial quality of tank water. In this study, the abundance and diversity of bacterial communities in 88 tank water samples collected from the urban areas of Brisbane (n = 44) and the peri-urban center of Currumbin (n = 44) in Southeast Queensland, Australia were determined using amplicon-based Illumina next-generation sequencing. In addition, the SourceTracker program was used to identify the sources of fecal contamination in tank water samples. Sequence reads were also analyzed to detect potential bacterial pathogenic genera in the tank water samples collected. Differences in sample coverage, alpha diversity, and richness did not differ significantly between the Brisbane and Currumbin tank water samples. Comamonadaceae and Planctomycetaceae were the most abundant families in all tank water samples. Curvibacter was the most abundant genus in all tank water samples. SourceTracker revealed that around 34% (Brisbane) and 43% (Currumbin) of tank water samples had a signature for bird fecal contamination. The potential opportunistic pathogenic genera including Burkholderia, Chromobacterium, Clostridium, Legionella, Mycobacterium, Nocardia, and Pseudomonas were most prevalent in tank water samples. Next-generation sequencing can be used as an initial screening tool to identify a wide array of potential pathogenic genera in tank water samples followed by quantifying specific pathogen(s) of interest using more sensitive molecular assays such as quantitative PCR (qPCR).
Bibliographical noteFunding Information:
This research was undertaken and funded as part of a Fulbright-CSIRO Postgraduate Scholarship sponsored by the CSIRO Land and Water Flagship. We sincerely thank the residents of Brisbane and the Currumbin Ecovillage for providing access to their rainwater tanks. We also thank Ms. Kylie Smith and Mr. Andrew Palmer for aiding in sample collection. Sequence data were processed and analyzed using the resources of Minnesota Supercomputing Institute.
- 16S rRNA amplicons
- Harvested rainwater
- Health risks
- Next-generation sequencing
- Pathogenic bacteria
- Source tracking