Reduced Efficiency of Chlorine Disinfection of Naegleria fowleri in a Drinking Water Distribution Biofilm.
Naegleria fowleri associated with biofilm and biological demand water (organic matter suspended in water that consumes disinfectants) sourced from operational drinking water distribution systems (DWDSs) had significantly increased resistance to chlorine disinfection. N. fowleri survived intermittent chlorine dosing of 0.6 mg/L for 7 days in a mixed biofilm from field and laboratory-cultured Escherichia coli strains. However, N. fowleri associated with an attached drinking water distribution biofilm survived more than 30 times (20 mg/L for 3 h) the recommended concentration of chlorine for drinking water. N. fowleri showed considerably more resistance to chlorine when associated with a real field biofilm compared to the mixed laboratory biofilm. This increased resistance is likely due to not only the consumption of disinfectants by the biofilm and the reduced disinfectant penetration into the biofilm but also the composition and microbial community of the biofilm itself. The increased diversity of the field biofilm community likely increased N. fowleri's resistance to chlorine disinfection compared to that of the laboratory-cultured biofilm. Previous research has been conducted in only laboratory scale models of DWDSs and laboratory-cultured biofilms. To the best of our knowledge, this is the first study demonstrating how N. fowleri can persist in a field drinking water distribution biofilm despite chlorination.
Microbiology and Immunology, School of Pathology and Laboratory Medicine, University of Western Australia , 35 Stirling Highway, Crawley, Western Australia 6009, Australia.|Water for a Healthy Country Flagship, Centre for Environment and Life Sciences, CSIRO Land and Water, Private Bag No. 5, Wembley, Western Australia 6913, Australia.
Haylea C
HC
Miller
Water for a Healthy Country Flagship, Centre for Environment and Life Sciences, CSIRO Land and Water, Private Bag No. 5, Wembley, Western Australia 6913, Australia.
Jason
J
Wylie
Water for a Healthy Country Flagship, Centre for Environment and Life Sciences, CSIRO Land and Water, Private Bag No. 5, Wembley, Western Australia 6913, Australia.|Pierre Gauthier Street, 33320 Eysines, France.
Guillaume
G
Dejean
Water for a Healthy Country Flagship, Centre for Environment and Life Sciences, CSIRO Land and Water, Private Bag No. 5, Wembley, Western Australia 6913, Australia.|School of Pathology and Laboratory Medicine and Oceans Institute, University of Western Australia , 35 Stirling Highway, Crawley, Western Australia 6009, Australia.
Anna H
AH
Kaksonen
School of Pathology and Laboratory Medicine and Oceans Institute, University of Western Australia , 35 Stirling Highway, Crawley, Western Australia 6009, Australia.
David
D
Sutton
Water Corporation of Western Australia , 629 Newcastle Street, Leederville, Western Australia 6007, Australia.
Kalan
K
Braun
Water for a Healthy Country Flagship, Centre for Environment and Life Sciences, CSIRO Land and Water, Private Bag No. 5, Wembley, Western Australia 6913, Australia.
Geoffrey J
GJ
Puzon
D018441:Biofilms / Q000187:drug effects*; D002713:Chlorine / Q000494:pharmacology*; D004202:Disinfectants / Q000494:pharmacology*; D004203:Disinfection; D060766:Drinking Water / Q000382:microbiology*; D050296:Microbial Viability / Q000187:drug effects; D016848:Naegleria fowleri / Q000187:drug effects*; D014871:Water Microbiology; D014881:Water Supply
D004202:Disinfectants; D060766:Drinking Water; D002713:Chlorine