You are here:
Eukaryotic diversity in premise drinking water using 18S rDNA sequencing: implications for health risks
Citation:
Buse, H., J. Lu, I. Struewing, AND N. Ashbolt. Eukaryotic diversity in premise drinking water using 18S rDNA sequencing: implications for health risks. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH. Ecomed Verlagsgesellschaft AG, Landsberg, Germany, 20(9):6351-6366, (2013).
Impact/Purpose:
The goal of this study was to characterize microbial eukaryotes over a 12 month period, so as to provide insight into the occurrence of potentially important predators and bacterial hosts in hot and cold premise plumbing.
Description:
The goal of this study was to characterize microbial eukaryotes over a 12 month period, so as to provide insight into the occurrence of potentially important predators and bacterial hosts in hot and cold premise plumbing. Nearly 6,300 partial (600 bp) 18S rRNA gene sequences from twenty-four hot (36.9 – 39.0 °C) and cold (6.8 – 29.1 °C) drinking water samples was collected and grouped into major eukaryotic categories based on ≥ 97% sequence similarity as the operational taxonomic unit (OTU). Each major group, consisting of free-living amoebae (FLA), algae, copepods, dinoflagellates, fungi, nematodes and unique uncultured eukaryotic sequences, showed limited OTU diversity dominated by 1-2 major members, which may be characteristic of drinking water oligotrophic environments. Increases in the abundance of predators such as nematodes in summer cold water versus hot water and throughout the year for copepods in hot vs cold water samples appears to be mostly related to water temperature and seasonal changes in water quality; while the changes in FLA abundance appeared to be attributed to temperature and the likely presence of different prey bacteria. Sequences nearly identical to FLA such as Hartmannella vermiformis, Echinamoeba thermarmum, Pseudoparamoeba pagei, Protacanthamoeba bohemica, Platyamoeba sp., Vannella sp., and V. miroides were obtained. Most of these amoebae are known to contain amoeba-resisting bacteria and may also serve as hosts to opportunistic bacterial pathogens such as Legionella pneumophila, thus representing potentially important hosts for amplification and maintenance of water-based pathogens. In addition to FLA, various copepods, rotifers and nematodes members have been reported to internalize viral and bacterial pathogens within drinking water systems. Hence potentially serving as transport hosts; the implications of which are discussed further. Increasing the knowledge on the occurrence of eukaryotes and their relationship with potential pathogens and the finding of possible toxigenic dinoflagellates should aid in assessing microbial risk associated with higher eukaryotic organisms in drinking water.
