Distributions of Antibiotic Resistance Genes and Microbial Communities in the Nearshore Area of the Yangtze River Estuary

Abstract

Due to the extensive use of antibiotics, the resistance of microorganisms to antibiotics in the environment is increasing, and the problem of antibiotic resistance genes (ARGs) is becoming more and more severe, which seriously threatens ecological security and human health. In order to study the distribution characteristics of ARGs and the microbial community in different media in the coastal area of the Yangtze River Estuary, water and sediment samples from eight sites were collected through a field investigation. Two sulfonamide resistance genes ([STBX]sul1, sul2[STBZ]) and six tetracycline resistance genes (tetM, tetC, tetX, tetA, tetO, and tetQ), one integrase gene intI[STBX]1[STBZ], 16S rRNA gene, and the microbial community were detected and analyzed. The results showed that the detection rate of 10 resistance genes in the coastal area of the Yangtze River Estuary was 100%. [STBX]intI1[STBZ] was significantly positively correlated with various ARGs in the water samples. Proteobacteria and Bacteroidota were the dominant bacteria phyla in the water environment of the Yangtze River Estuary. Chloroplast was the main bacteria genus in water, and Chloroplast and Nitrospira were the main bacteria genera in sediment. In water, Nitrospirota was the common potential host of four tetracycline resistance genes (tetX, tetA, tetO, and tetQ). In sediments, Sva0485 was a potential host community shared by [STBX]sul1 and intI1[STBZ]. The distribution of the microbial community was an important factor affecting the migration and transformation of ARGs in the nearshore area of the Yangtze River Estuary.