@article{SJ Moodley_P Muchesa_C Bartie_TG Barnard_R Clarke_A Masenge_SN Venter_2023, title={Prevalence of free-living acanthamoeba and its associated bacteria in energy-efficient hot water systems in South Africa}, volume={49}, url={https://watersa.net/article/view/15536}, DOI={10.17159/wsa/2023.v49.i1.3947}, abstractNote={<p>As part of the Eskom rebate programme, energy-efficient hot water systems such as solar water heaters (low pressure), heat pumps and energy-efficient showerheads were rolled out to the public as a measure to conserve and save energy.  There has been a concern that these systems may not reach the required high temperatures, especially during winter, and, as a result of this, <em>Acanthamoeba</em> and its associated bacteria such as <em>Legionella </em><em>pneumophila, Pseudomonas aeruginosa </em>and nontuberculous mycobacteria could flourish within these systems causing a potential health risk to consumers.  This study examined the relationship between <em>Acanthamoeba</em> and its associated bacteria at different temperature ranges. A total of 156 water (69) and biofilm samples (87) were collected from a solar water heater, heat pump, geyser and showerheads and examined for these organisms using amoebal enrichment and molecular techniques.   Amoeba could be cultivated from 45 (65.2%) of the water samples and 56 (64.4%) of the biofilm samples. The study confirmed the presence of <em>Legionella </em><em>pneumophila, Pseudomonas aeruginosa </em>and nontuberculous mycobacteria in the hot water systems at both of the simulated winter (20°C to 30°C) and higher summer (40°C to 55°C) temperatures as well as the control system.  There was a significant positive correlation between the presence of <em>Acanthamoeba</em> and the presence of <em>Pseudomonas</em>. Based on this association it is suggested that <em>Pseudomonas aeruginosa </em>could be investigated as an indicator organism for the presence of <em>Acanthamoeba</em> and opportunistic pathogens.</p>}, number={1 January}, journal={Water SA}, author={SJ Moodley and P Muchesa and C Bartie and TG Barnard and R Clarke and A Masenge and SN Venter}, year={2023}, month={Jan.} }