title: Effect of Disinfectant Exposure on Legionella pneumophila Associated with Simulated Drinking Water Biofilms: Release, Inactivation, and Infectivity.
abstract: Legionella pneumophila, the most commonly identified causative agent in drinking water associated with disease outbreaks, can be harbored by and released from drinking water biofilms. In this study, the release of biofilm-associated L. pneumophila under simulated drinking water flow containing a disinfectant residual was examined. Meanwhile, the inactivation and infectivity (to amoebae) of the released L. pneumophila were studied. To simulate drinking water system conditions, biofilms were prepared under either disinfectant exposure (predisinfected biofilms) or disinfectant-free (untreated biofilms) conditions, respectively. For experiments with water flow containing a disinfectant to release the biofilm-associated L. pneumophila from these two types of biofilms, the L. pneumophila release kinetics values from predisinfected and untreated biofilms under flow condition were not statistically different (one-way ANOVA, p > 0.05). However, inactivation of the L. pneumophila released from predisinfected biofilms was 1-2 times higher and amoeba infectivity was 2-29 times lower than that from untreated biofilms. The higher disinfectant resistance of L. pneumophila released from untreated biofilms was presumably influenced by the detachment of a larger amount of biofilm material (determined by 16S rRNA qPCR) surrounding the released L. pneumophila. This study highlights the interaction among disinfectant residual, biofilms, and L. pneumophila, which provides guidelines to assess and control pathogen risk.
authors.affiliation: Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801-2352, United States.
authors.forename: Yun
authors.identifier: 0000-0002-8225-1940
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801-2352, United States.
authors.forename: Conghui
authors.initials: C
authors.lastname: Huang
authors.affiliation: Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801-2352, United States.
authors.forename: Jie
authors.initials: J
authors.lastname: Lin
authors.affiliation: Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801-2352, United States.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Wu
authors.affiliation: School of Public Health, University of Alberta , Edminton, Alberta AB T6G 2G7, Canada.
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Ashbolt
authors.affiliation: Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801-2352, United States.
authors.forename: Wen-Tso
authors.initials: WT
authors.lastname: Liu
authors.affiliation: Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801-2352, United States.
authors.forename: Thanh H
authors.initials: TH
authors.lastname: Nguyen
mesh_terms: D018441:Biofilms / Q000187:drug effects; D004202:Disinfectants / Q000494:pharmacology; D060766:Drinking Water; D016952:Legionella pneumophila / Q000235:genetics*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014871:Water Microbiology; D014881:Water Supply
chemical_list: D004202:Disinfectants; D060766:Drinking Water; D012336:RNA, Ribosomal, 16S