The effect of enrofloxacin exposure on energy metabolism and the ARGs transmission in grass carp: Potential contribution of microbiota-gut-liver axis

Abstract

Enrofloxacin is one of the antibiotics commonly used in aquaculture. Nevertheless, the precise mechanisms underlying its toxicological effects on the energy metabolism of organisms remain elusive. Therefore, we conducted experiments employing grass carp (Ctenopharyngodon idellus) as our model organism, subjecting them to varying concentrations of ENR for a duration of 21 days followed by a 14-day purification period. Our results revealed that ENR exposure led to disturbances in the intestinal flora of grass carp, inducing hypoglycemia by impeding gluconeogenesis while promoting glycolysis and aerobic metabolism. Additionally, it curtailed lipid utilization and catabolism in grass carp, resulting in hepatic function impairment and metabolic disorders. The effects were partially alleviated after a 14-day purification period, but the damage to the grass carp continued. Furthermore, our investigation unveiled a significant association between the top 20 abundant genera and biomarkers of energy metabolism, providing further insights into the intricate interplay of the microbial-gut-liver axis. Concurrently, we detected 6 common quinolone resistance genes in the experimental group, indicating a potential risk of antimicrobial resistance genes (ARGs) transmission, which could lead to environmental pollution and pose threats to human health.