Insight into the Effects of Norfloxacin on Bacterial Community and Antibiotic Resistance Genes during Chicken Manure Composting

Abstract

Composting emerges as an effective strategy to eliminate antibiotics and antibiotic resistance genes (ARGs) in animal manure. In this study, chicken manure with the addition of wheat straw and sawdust was used as composting raw materials, and different concentrations of norfloxacin were added to investigate its effects on physicochemical properties, bacterial community, and ARGs during the composting process. Results show that the presence of norfloxacin has obvious effects on the composting physicochemical properties and germination index (GI). A high concentration of norfloxacin influences the succession direction of the bacterial community and promotes the transfers of gyrA, gyrB, parC, qepA, and qnrB. The composting physicochemical properties alter bacterial communities and further influence the fate of ARGs. These results suggest that meticulous management of antibiotic usage and compost conditions are vital strategies for mitigating the influx of antibiotics and ARGs into the environment, both at the source and on the path.