title: Bacteria-mediated effects of antibiotics on Daphnia nutrition.
abstract: In polluted environments, contaminant effects may be manifested via both direct toxicity to the host and changes in its microbiota, affecting bacteria-host interactions. In this context, particularly relevant is exposure to antibiotics released into environment. We examined effects of the antibiotic trimethoprim on microbiota of Daphnia magna and concomitant changes in the host feeding. In daphnids exposed to 0.25 mg L(-1) trimethoprim for 24 h, the microbiota was strongly affected, with (1) up to 21-fold decrease in 16S rRNA gene abundance and (2) a shift from balanced communities dominated by Curvibacter, Aquabacterium, and Limnohabitans in controls to significantly lower diversity under dominance of Pelomonas in the exposed animals. Moreover, decreased feeding and digestion was observed in the animals exposed to 0.25-2 mg L(-1) trimethoprim for 48 h and then fed 14C-labeled algae. Whereas the proportion of intact algal cells in the guts increased with increased trimethoprim concentration, ingestion and incorporation rates as well as digestion and incorporation efficiencies decreased significantly. Thus, antibiotics may impact nontarget species via changes in their microbiota leading to compromised nutrition and, ultimately, growth. These bacteria-mediated effects in nontarget organisms may not be unique for antibiotics, but also relevant for environmental pollutants of various nature.
authors: †Department of Environmental Science and Analytical Chemistry, Stockholm University, SE-114 18 Stockholm, Sweden.
authors: Elena
authors: E
authors: Gorokhova
authors: ‡Department of Environmental Chemistry, IDÆA-CSIC, Jordi Girona 18, 08034 Barcelona, Spain.
authors: Claudia
authors: C
authors: Rivetti
authors: †Department of Environmental Science and Analytical Chemistry, Stockholm University, SE-114 18 Stockholm, Sweden.
authors: Sara
authors: S
authors: Furuhagen
authors: §Microbial and Environmental Genomics, J. Craig Venter Institute, 4120 Capricorn Lane, La Jolla, California 92037, United States.
authors: Anna
authors: A
authors: Edlund
authors: †Department of Environmental Science and Analytical Chemistry, Stockholm University, SE-114 18 Stockholm, Sweden.
authors: Karin
authors: K
authors: Ek
authors: †Department of Environmental Science and Analytical Chemistry, Stockholm University, SE-114 18 Stockholm, Sweden.
authors: Magnus
authors: M
authors: Breitholtz
mesh_terms: D000824:Animal Nutritional Physiological Phenomena / Q000187:drug effects*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001419:Bacteria / Q000378:metabolism*; D044822:Biodiversity; D003621:Daphnia / Q000187:drug effects* / Q000382:microbiology*; D005247:Feeding Behavior / Q000187:drug effects; D008969:Molecular Sequence Data; D010802:Phylogeny; D014295:Trimethoprim / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D014295:Trimethoprim