A perspective on treatment technologies for swine wastewater: addressing bacterial resistance

Pig farming relies heavily on antibiotics, many of which are also critical to human medicine, leading to their release into pig manure and swine wastewater. The presence of such compounds in the environment is associated with ecotoxicological effects and the proliferation of antibiotic resistance genes. Therefore, swine wastewater is closely linked to the spread of antimicrobial resistance because it may act as a reservoir, a concentrator and an environmental dissemination route for antibiotics, resistance bacteria or antibiotic resistance genes. This contamination potential will depend on the applied treatment (adequacy and efficiency), which will then determine whether the treated effluent and its value-added byproducts are microbiologically safe. This paper presents the treatment systems for swine wastewater observed from broad literature research. Then, the main technologies that have addressed antimicrobial resistance are discussed from a resistome perspective, accounting for performance and limitations. Overall, priority should be given to improving antimicrobial resistance stewardship and surveillance, fostering the development of innovative antimicrobials, and ensuring effective pig wastewater treatment through engineering solutions that include post-treatment and integrated systems. • Pig farming environments are a hotspot for the spread of antimicrobial resistance. • There is a knowledge gap of resistome behavior in swine wastewater treatment. • Anaerobic digestion may act as a reservoir of antibiotic resistance genes. • The concept of biorefineries must account for antimicrobial resistance risks. • Integrated treatments offer benefits, but cost and scalability remain challenges.