Florfenicol in aquaculture: environmental fate of residues and dissemination of antimicrobial resistance genes

Abstract Florfenicol (FFC) has become a significant antibiotic in the global aquaculture industry, particularly in the treatment of bacterial infections in finfish and shellfish. FFC is valued for its broad-spectrum bacteriostatic activity and effectiveness. This comprehensive review consolidates and expands upon existing research, offering in-depth information on FFC application across various aquaculture practices. This review addresses the key pharmacokinetic aspects of FFC, such as its absorption, distribution, metabolism, and excretion, in aquatic species. Significant attention is given to the safety profile of FFC, with discussions on residue accumulation, elimination dynamics, and the established withdrawal periods necessary to ensure consumer safety. Furthermore, this review highlights emerging issues related to FFC in aquaculture, particularly with respect to plasmid-mediated resistance, the dispersal of resistant bacteria and resistance genes, and their impact on the aquatic environment and nontarget organisms, laying a foundation for future research in this critical area. This evaluative assessment offers a novel contribution to the field, serving as an essential reference for ongoing and future studies on the appropriate use and prevention of FFC resistance in aquatic animal medicine.