Comprehensive study of sulfamethoxazole effects in marine mussels: Bioconcentration, enzymatic activities and metabolomics

11 pages, 9 figures, supplementary material https://doi.org/10.1016/j.envres.2019.03.021Antibiotics accumulation in aquatic organisms may be of great concern from an ecological point of view but also from a human perspective, especially when they are accumulated in edible animals like marine mussels. In this work, mussels (Mytilus galloprovincialis) were exposed to sulfamethoxazole antibiotic (SMX) at 10 µg/L during 96 h, followed by 24 h of depuration. The experiment was carried out at summer and winter conditions. SMX showed a bioconcentration factor in mussel of 1.5 L/kg (dry weight) and 69% of the compound was eliminated from the organism in 24 h. The metabolomics approach revealed alterations in amino acids levels (aspartate, phenylalanine, valine and tryptophan) pinpointing disturbances in osmotic regulation and energy metabolism. Besides, the levels of some nucleotides (guanosine and inosine) and a carboxylic acid were also affected. However, SMX exposed mussels did not show any significant alteration in the enzymatic activities related to the xenobiotic metabolism and oxidative stress. Moreover, some of the changes observed in mussel's metabolites suggested alterations in mussel's organoleptic characteristics that can affect its quality as seafood commodity. Overall, our results showed that SMX exposure to marine mussels may have ecological implications by provoking sub-lethal effects to exposed organisms. Nevertheless, no risk for consumers derived from mussel ingestion is expected due to the low bioconcentration capacity of SMX and fast depuration in this seafood typeThis work has received funding from SEA-on-a-CHIP project under grant agreement No.614168 from European Union's Seventh Framework Program (FP7-OCEAN-2013) and been also supported by the Spanish Ministry of Economy and Competitiveness through the PLAS-MED (CTM2017-89701-C3-2-R) and AIMCOST (CGL2016-76332-R MINECO/FEDER/UE) projects. Authors acknowledge the support from the Economy and Knowledge Department of the Catalan Government through Consolidated Research Group (ICRA-ENV 2017 SGR 1124 and 2017-SGR-1404-Water and Soil Quality Unit). Albert Serra-Compte acknowledges the FI-DGR research fellowship from the Catalan Government (2018FI_B2_00170). Sara Rodriguez-Mozaz acknowledges the Ramon y Cajal program (RYC-2014-16707) and Diana Álvarez-Muñoz the support of the project XENOMETABOLOMIC (CTM2015-73179-JIN) (AEI/FEDER/UE)Peer Reviewe