Daphnia stress response to environmental concentrations of chloramphenicol

Commonly used medicines, when discarded or improperly disposed of, are known to contaminate freshwater ecosystems. Pharmaceuticals can be toxic, mutagenic, and can modify freshwater organisms, even at low concentrations if one considers their permanent presence in the environment. The aim of this study was to evaluate the impact of chloramphenicol (CAP) contamination in freshwater on the model organism Daphnia magna. Specific life history parameters, transcriptome, proteome, and host-associated microbiome of four D. magna clones were analysed during a three-generation exposure to CAP at environmental concentrations (32 ng L^-1). In the first generation, no statistically significant CAP effect at the individual level was detected. After three-generations, exposed animals were smaller at first reproduction and on average producing less offspring. Daphnia’s response to CAP presence indicates the high stress that the tested organisms are under, e.g. male production, upregulation of ubiquitin-conjugating enzyme E2 and calcium-binding protein, downregulation of glutathione transferase. Microbiome analysis showed a significant difference in the community diversity between the control and the chloramphenicol-treated samples. The ecotoxicogenomic approach together with long exposure in the laboratory imitating conditions in a polluted environment allows us to obtain a more complete picture of the CAP impact on Daphnia. This work was supported by the National Science Centre, Poland UMO-2021/03/Y/NZ9/00141 under the framework of JPIAMR-ACTION GA no 963864.

Primary Presenter: Adrian Gorecki, Warsaw University of Life Sciences (SGGW) (adrian_gorecki@sggw.edu.pl)

Authors:

Adrian Gorecki, Warsaw University of Life Sciences (SGGW),Department of Biochemistry and Microbiology, Institute of Biology  (adrian_gorecki@sggw.edu.pl)

Marta Grabska, Warsaw University of Life Sciences (SGGW),Department of Biochemistry and Microbiology, Institute of Biology  (martag999@interia.eu)