Poultry by-product feeding as a vector for antibiotic residues and microbiota shifts in yellow catfish (Pelteobagrus fulvidraco) aquaculture

Abstract

Poultry by-products (PBPs) are increasingly used in aquacultural environments and have emerged as a potential source of veterinary antibiotics and pathogens; however, the ecological risks remain unclear. This study investigated tissue-specific accumulation of 34 antibiotics and microbial risks in yellow catfish (Pelteobagrus fulvidraco) following exposure to PBPs. Among the 11 tissues analyzed, the data suggest that over 93% of antibiotic residues may be derived from PBPs, with concentrations ranging from 1.21 to 354.31 ng g^-1, with the highest concentrations observed in bile, kidney, and liver. Bioaccumulation of tilmicosin, enrofloxacin, and florfenicol occurred via both dietary intake and dermal exposure, with log bioaccumulation factor (BAF) values of up to 3.79 for bile. High-throughput 16S rRNA sequencing revealed the consistent occurrence of Acinetobacter and Mycobacterium across fish tissues, feed, and water, with 40% of dominant taxa identified as known or suspected cross-species potentially pathogenic genera. A significant reduction in skin microbiota diversity further indicates a possible risk of exposure-induced dysbiosis. These findings highlight PBPs as vectors of both antibiotic residues and microbial disturbance, underscoring the need for targeted control of PBP-derived risks to safeguard freshwater ecosystem health.