A dynamic and complex monochloramine stress response in Escherichia coli revealed by transcriptome analysis

• Published in: Water research (Oxford) 2013-09, Vol.47 (14), p.4978-4985
• Main Authors: Holder, Diane, Berry, David, Dai, Dongjuan, Raskin, Lutgarde, Xi, Chuanwu
• Format: Article
• Language: English
• Subjects: Antibiotic resistance; Antibiotics; antioxidants; Applied sciences; Biofilm; Biofilms; Biofilms - drug effects; Cell Membrane - drug effects; Cell Membrane - genetics; cell membranes; cell walls; Chloramines - pharmacology; Disinfectants - pharmacology; Disinfection; DNA microarrays; DNA repair; Drinking water; Drug Resistance, Bacterial - drug effects; Drug Resistance, Bacterial - genetics; Dynamic tests; Dynamics; Escherichia coli; Escherichia coli - drug effects; Escherichia coli - genetics; Escherichia coli - physiology; Escherichia coli Proteins - genetics; Exact sciences and technology; Exposure; gene expression; Gene Expression Profiling; Gene Expression Regulation, Bacterial - drug effects; Genes; Kinetics; mechanism of action; Microarray; Monochloramine; nucleic acids; Oligonucleotide Array Sequence Analysis; oxidative stress; Pollution; Promoter Regions, Genetic; Recombinant Fusion Proteins - genetics; stress response; Stress, Physiological; Stresses; transcriptomics; transporters; water treatment; Water treatment and pollution
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2013.05.041

Despite the widespread use of monochloramine in drinking water treatment, there is surprisingly little information about its mode of action. In this study, DNA microarrays were used to investigate the global gene expression of Escherichia coli cells exposed to sub-lethal concentrations of monochloramine, with a focus on temporal dynamics. Genes induced by monochloramine were associated with several stress response functions, including oxidative stress, DNA repair, multidrug efflux, biofilm formation, antibiotic resistance, and cell wall repair. The diversity of functional associations supports a model of monochloramine action involving multiple cellular targets including cell membranes, nucleic acids, and proteins. These data suggest that E. coli responds to monochloramine exposure by activating diverse defense responses rather than a single antioxidant system and the exposure may also induce biofilm formation. The induction of multidrug efflux pumps and specific antibiotic resistance genes further suggests that exposure to monochloramine may contribute to reduced susceptibility to some antibiotics. [Display omitted] •Transcriptomic response of Escherichia coli to monochloramine is temporally dynamic.•Results support a model of monochloramine targeting multiple cellular components.•Stress responses were diverse, ranging from oxidative stress to biofilm formation.•Exposure to monochloramine may lead to reduced susceptibility to other stresses.