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Developmental exposure to triclosan alters microbiota community structure and locomotor activity in larval zebrafish
Tal, T., D. Phelps, S. Keely, N. Brinkman, D. Hunter, A. Gearhart, D. Betancourt, C. McQueen, AND C. Wood. Developmental exposure to triclosan alters microbiota community structure and locomotor activity in larval zebrafish. SOT, Baltimore, MD, March 12 - 17, 2017.
This abstract describes data showing that triclosan may exert behavioral effects in zebrafish larvae via dysregulation of microbial colonization during development.
Growing evidence indicates that host-associated microbiota modify the toxicokinetics and/or toxicodynamics of environmental chemicals; however, current risk assessment methods do not consider interactions between microbiota and chemical toxicity. We previously reported that microbial colonization is required for normal neurobehavioral development in zebrafish. We therefore hypothesized that neurobehavioral toxicity may be mediated by altered microbial colonization during development. Here, we explored differences in swimming behavior and bacterial community structure in sterile (axenic) and conventionally raised zebrafish exposed to the antimicrobial triclosan (0-0.3 uM) during development. Neurobehavioral function was assessed using a standard locomotor assay consisting of alternating light and dark periods. At 10 days post fertilization (dpf), triclosan exposure had no effect on locomotor activity in axenic larvae where sterility was confirmed by 16S ribosomal DNA sequencing. In comparison, locomotor hypoactivity was observed in conventionally raised larvae exposed to 0.3 uM triclosan. Triclosan exposure also triggered concentration-dependent shifts in microbial community structure at 10 dpf in conventionally raised larvae that primarily mapped to the Proteobacteria phylum where Betaproteobacteria levels decreased while Gammaproteobacteria including Vibrio and Pseudomonas flourished in triclosan-exposed larvae. Taken together, microbial colonization appears to be required for triclosan-dependent behavioral outcomes. Further, triclosan-induced behavioral effects were accompanied by concentration-dependent shifts in the community structure of resident microbiota. These data suggest that triclosan may exert behavioral effects via dysregulation of microbial colonization during development. This abstract does not necessarily reflect EPA policy.
Record Details:Record Type: DOCUMENT (PRESENTATION/POSTER)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL HEALTH AND ENVIRONMENTAL EFFECTS RESEARCH LABORATORY
INTEGRATED SYSTEMS TOXICOLOGY DIVISION
SYSTEMS BIOLOGY BRANCH