Spatial distribution of antibiotic resistance genes in marine sediments of east China seas

ARGs were considered an emerging contaminant due to their ability to fail antibiotic therapy and extensive occurrence in various environmental matrices. A full profile of the occurrence of ARGs in seas is therefore critical for evaluating strategies to regulate ARGs pollution. This study performed a large-scale sampling in the seas of China and evaluated the abundance of ARGs. β-lactam resistance genes blaTEM were shown to be ubiquitous and predominant in all sea areas with the highest relative abundances up to 2.7 × 10−3, while clinically relevant vancomycin resistance genes (vanA) were only detected in the Bohai sea and held the lowest abundances of 5.2 × 10−7. The total ARG abundances in the sediments increased from north to south, where the South China Sea held the highest and the Bohai Sea held the lowest. Contents of nitrate, organic carbon and total carbon were major physicochemical properties that regulated the distribution and variation of blaTEM and tetC in the sediments. Bacteroidetes and Firmicutes were dominant potential host bacteria of blaTEM, tetC, sul1, and intI1. This study provides new insight into the pollution status of ARGs in sea areas of China, which contributes to ARGs risk assessment and raises awareness of managing antibiotic resistance pollution.