Mariculture affects antibiotic resistome and microbiome in the coastal environment

Antibiotics are increasingly used and released into the marine environment due to the rapid development of mariculture, resulting in spread of antibiotic resistance. The pollution, distribution, and characteristics of antibiotics, antibiotic resistance genes (ARGs) and microbiomes have been investigated in this study. Results showed that 20 antibiotics were detected in Chinese coastal environment, with predominance of erythromycin-H2O, enrofloxacin and oxytetracycline. In coastal mariculture sites, antibiotic concentrations were significantly higher than in control sites, and more types of antibiotics were detected in the South than in the North of China. Residues of enrofloxacin, ciprofloxacin and sulfadiazine posed high resistance selection risks. beta-Lactam, multidrug and tetracycline resistance genes were frequently detected with significantly higher abundance in the mariculture sites. Of the 262 detected ARGs, 10, 26, and 19 were ranked as high-risk, current-risk, future-risk, respectively. The main bacterial phyla were Proteobacteria and Bacteroidetes, of which 25 genera were zoonotic pathogens, with Arcobacter and Vibrio in particular ranking in the top10. Opportunistic pathogens were more widely distributed in the northern mariculture sites. Phyla of Proteobacteria and Bacteroidetes were the potential hosts of high-risk ARGs, while the conditional pathogens were associated with future-risk ARGs, indicating a potential threat to human health.

Automated summary

Antibiotics are being used extensively in mariculture, leading to the spread of antibiotic resistance in the marine environment. This study investigated the pollution, distribution, and characteristics of antibiotics, antibiotic resistance genes (ARGs), and microbiomes. The findings revealed the presence of 20 antibiotics in Chinese coastal areas, with higher concentrations and more types of antibiotics detected in mariculture sites compared to control sites. Certain antibiotics, such as enrofloxacin, ciprofloxacin, and sulfadiazine, posed a high risk of resistance selection. The study also highlighted the presence of high-risk ARGs in certain bacterial phyla, suggesting a potential threat to human health.