Metagenomics Analysis Reveals The Microbial Communities, Antimicrobial Resistance Gene Diversity And Potential Pathogen Transmission in Aquaculture Ponds

Aquaculture sediments have become an important reservoir of antibiotic resistant bacterial and antibiotic resistant genes (ARGs), while little is known about the composition and transmission of ARGs and potential pathogens in aquaculture sediments. In order to reveal diversity and abundance of ARGs and antibiotic resistant bacterial in sediment of aquaculture ponds in Shaanxi province, twelve sediments samples from aquaculture ponds located 4 arears in Shaanxi province were investigated and analyzed using 16S rRNA gene sequencing and metagenomics sequencing. Proteobacteria was dominant groups in the tested sediments, accounting for 40% ~ 60% of the total sequences, followed by Chloroflexi and Bacteroidetes. A total of 422 ARGs were detected that conferred resistance to β-lactams (120 ARGs), multidrug (59 ARGs) aminoglycoside resistant genes (55 ARGs) and more. Antibiotic inactivation (199 ARGs) and antibiotic efflux pump (137 ARGs) were the largely resistant mechanisms. The highest abundance of ARGs was blaTEM-116, followed by adeF and TriA. Twenty-seven human pathogens, as bacterial hosts of ARGs, included in Salmonella, Eubacterium, Aeromonas and Bdellovibrio were identified in the tested aquaculture sediments. The concentration of total phosphorus (TN), total nitrogen (TP) can affect the diversity of bacterial community, and further influence the type and abundance of ARGs. The results can provide useful information for better assessing the environmental and ecological safety of the aquaculture environment.