antibiotic resistance genes and aquaculture environment

Antibiotic resistance genes (ARGs) pose a serious threat to environment and human health. However, relatively few studies have explored the abundance and distribution of farmed fish and the related environment in aquaculture. This study investigated the abundance and distribution of ARGs and bacterial communities in fish (Lateolabrax japonicus) gut, gill and surrouding environment (water and sediment) from six aquaculture ponds as well as the related water and sediment properties in Guangdong, South China. Our results showed that floR, sul2, and tetM-01 were the predominant ARGs in the fish gut. By contrast, tetQ, sul1 and floR were the dominant in the fish gill. The environment had more copy number of sul1, sul2 and cmlA1-01. The bacterial community structures had significant difference among gut, gill and environmental microbiotas. The fish gut microbiota was more similar to water microbial communities compared with other samples. In addition, the fish gut and gill were predominant by Fusobacteria and Actinobacteria, respectively. In contrast, Proteobacteria was dominant in the water and sediment. Correlation analysis showed that Fusobacteria was positively correlated with floR, and Actinobacteria was positively correlated with tetQ, indicating that the these microbes associated with fish were potential hosts for ARGs. Water pH, dissolved oxygen (DO) and sediment pH also showed correlations with some specific ARGs, such as tetQ, tetM-01, and vanA. This study exhibits a case study of the spatial distribution of ARGs in the fish and related environment in aquaculture and provide a valuable reference for the potential determination of harmful ARGs on aquatic food safety and human health.