Interactions of erythromycin and an antibiotic-mixture to the gut microbiome of juvenile rainbow trout

ABSTRACT: Erythromycin (ERY) is a commonly used antibiotic that can be found in wastewater effluents globally. Due to the mechanisms by which they kill and prevent bacterial growth, antibiotics can have significant unwanted impacts on the fish gut microbiome. The overall objective of this project was to assess the effects of erythromycin and an antibiotic mixture on fish gut microbiomes. The project was split into two experiments to assess gut microbiome in response to exposure with ERY alone or in mixture with other common antibiotics. The objectives of experiment 1 were to understand uptake and depuration of ERY in juvenile rainbow trout (RBT) over a 7 d uptake followed by a 7 d depuration period using three concentrations of ERY. Furthermore, throughout the study changes in gut microbiome response were assessed. In experiment 2, a follow-up study was conducted using an identical experimental design to assess the impacts of an antibiotic-mixture (ERY, ampicillin, metronidazole, and ciprofloxacin at 100 µg/g each). Here, three matrices were analyzed, with gut collected for 16s metabarcoding, plasma for untargeted metabolomics, and brain for mRNA-seq analysis. ERY was depurated from the fish relatively quickly and gut microbiome dysbiosis was observed at 7 d after exposure, with a slight recovery after the 7 d depuration period. A greater number of plasma metabolites was dysregulated at 14 d compared to 7 d revealing temporality compared to gut microbiome dysbiosis. Furthermore, several transformation products of antibiotics and biomarker metabolites were observed in plasma due to antibiotic exposure. Brain transcriptome revealed only slight alterations due to antibiotic exposure. The results of these studies will help inform aquaculture practitioners and risk assessors when assessing the potential impacts of antibiotics in fish feed and the environment, with implications for host health.

ORGANISM(S): Oncorhynchus mykiss

PROVIDER: GSE253746 | GEO | 2024/02/07

REPOSITORIES: GEO