ORIGINAL RESEARCH article
Front. Microbiol.
Sec. Aquatic Microbiology
This article is part of the Research TopicMitigating Microbial Contamination of Drinking Water SourcesView all 10 articles
Efficacy of physical and chemical disinfection against clinically relevant free-living amoebae isolated from drinking water and plumbing biofilms
Provisionally accepted
Muhammad Atif Nisar1
Claire Hayward2*
Kirstin Ross1
Melissa Hackett Brown1
Richard Bentham1
Harriet Whiley1- 1Flinders University, Adelaide, Australia
- 2University of South Australia, Adelaide, Australia
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
Free-living amoebae (FLA) are widespread in drinking water systems and biofilms, posing public health risks both as pathogens themselves and as reservoirs for opportunistic bacteria such as Legionella spp. and Mycobacterium spp. Current water management practices often fail to effectively control these biofilms, allowing persistence of both FLA and intracellular pathogens. In this study the efficacy of different disinfectants (thermal disinfection (70oC), hydrogen peroxide, 2-methyl-4-isothiazolin-3-one, benzalkonium chloride, sodium hypochlorite and chlorine dioxide), at varying times and concentrations, against the planktonic trophozoites and cysts of Acanthamoeba DB1, Allovahlkampfia DS1, Stenamoeba DS1, Vermamoeba vermiformis HB7 and Acanthamoeba polyphaga ATCC® 30461™ was investigated. The most effective disinfection treatment against all FLA was thermal disinfection, followed by hydrogen peroxide. Thermal disinfection of 70°C for 45 min was effective at killing all FLA trophozoites (>4 log10 reduction) and 60 min was effective at killing all FLA cysts (>4 log10 reduction) except for V. vermiformis HB7. Future research is needed to explore the practical consideration of implementing these control strategies against biofilms formed on plumbing fixtures and in drinking water distribution systems.
Keywords: protozoa, Opportunistic pathogens, Potable water, Infection Control, Biofilm
Received: 27 Jun 2025; Accepted: 10 Nov 2025.
Copyright: © 2025 Nisar, Hayward, Ross, Brown, Bentham and Whiley. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Claire Hayward, claire.hayward@unisa.edu.au
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.