Antibiotic agents have been widely used for treating bacterial diseases in catfish aquaculture. However, antimicrobials may have substantial effects on the bacterial ecology of fish rearing ecosystem. Antimicrobial-resistant bacteria may be transferred and develop due to selective pressure from the medicated feed. In this work, we will pursue the main goals to investigate the impacts of florfenicol on antibiotic resistance in aquatic bacteria from simulated catfish production systems.