Integrating livestock and aquatic plant towards mitigating antibiotic resistance transmission from swine wastewater

Abstract

Load reduction is essential for mitigating the transmission risk of antibiotic resistance genes (ARGs) from livestock wastewater. This study examined the potential and mechanisms of Myriophyllum elatinoide-planted system in reducing ARGs in swine wastewater. Field experiment showed a progressive decline in ARG diversity and abundance as pond number increased, which was attributed to bacterial community shift and mobile genetic element-mediated horizontal transfer. This was corroborated by hydroponic experiment, where removal rates of antibiotics, antibiotic-resistant bacteria, and ARGs reached 64.82–87.83%, 66.27–98.39%, and 93.63–99.82%. Mechanistically, such a reduction could be achieved through direct uptake by plant roots and shoots, and indirectly by alleviating the selection pressure from antibiotic residues. Furthermore, M. elatinoides treatment substantially decreased ARG burdens in wastewater-receiving water (71.40–96.68%) and soils (36.81–85.69%). Our findings present a feasible and sustainable strategy for mitigating swine wastewater-borne ARGs, aiding in the fight against the spread of antibiotic resistance.