Effect of CeO(2) Nanoparticles on the Spread of Antibiotic Resistance in a Reclaimed Water-Soil-Radish System — Shenzhen City, Guangdong Province, China, April 2023

INTRODUCTION: The use of reclaimed water (RW) for irrigation in agricultural practices raises concerns regarding the dissemination of antibiotic resistance genes (ARGs) from soils to edible crops. The effectiveness of nanoparticles (NPs) in reducing antibiotic resistance in vegetables irrigated with RW remains largely unexplored. METHODS: To investigate the effects, we conducted pot experiments in which radishes were planted in soil amended with CeO(2) NPs using various application techniques. The abundance of ARGs was characterized using high-throughput quantitative PCR (HT-qPCR). Concurrently, we utilized 16S ribosomal RNA (rRNA) gene sequencing to evaluate the microbial community structure of both the rhizosphere soil and the endophytic compartment within the radishes. Employing bioinformatics analysis, we probed the potential mechanisms by which NPs influence the resistome within the reclaimed water-soil-radish system. RESULTS: Following the application of CeO(2) NPs, there was a noticeable reduction in both the number and concentration of ARG genotypes in the rhizosphere soil, as well as within the radish. Concurrently, CeO(2) NPs appeared to mitigate the propagation of ARGs within the reclaimed water-soil-radish system. The ability of CeO(2) NPs to modulate the resistome is linked to alterations in microbial community structure. Soil treatment with NPs emerged as the most effective strategy for curbing the spread of ARGs. DISCUSSION: This finding provides a theoretical foundation for the development of nano-agricultural technologies aimed at controlling the proliferation of ARGs.