循环水养殖系统水体中抗生素抗性基因的污染特征OA北大核心CSTPCD

The abuse of antibiotics has caused the propagation of antibiotic resistance genes(ARGs)in aquaculture environments.Although the recirculating aquaculture system(RAS)has been considered as an eco-friendly and promising approach for preventing the coastal water pollution of antibiotics and ARGs,rare information is available on the distribution and proliferation of ARGs in the RAS.Here,we investigated the dynamics of ARGs and bacterial community structures in each section of two RAS using high-throughput quantitative PCR and 16S rRNA Illumina sequencing analysis.We detected 8 types and 201 subtypes of ARGs in the two RAS environment.Among them,the tetracycline,sulfonamide,and multidrug resistance genes were dominant.The tetracycline resistance genes tetX and tetG-02 had the highest relative proportion in circulating water.The main bacterial phyla were Proteobacteria and Bacteroidetes and differences of bacteria genus were observed between the two RAS.Positive correlations exist between different ARG subtypes and bacterial genus,indicating the horizontal transfer and diffusion of ARGs among these different bacterial groups.Finally,TN,TP,NO3-N,and phosphate showed obvious influences on ARGs profiles and bacteria composition.Generally,our results illustrate that ARGs are prevalent in RAS and may pose potential risk to environment,which will help develop targeted strategies for the risk management and assessment of ARGs in the aquaculture.