[Ecological Risk and Microbial Diversity Characteristics of Antibiotics in Farm and Surrounding Environmental Media]

Farm manure is one of the largest sources of antibiotics in environmental media. At present, there are limited studies on antibiotic residues and microbial diversity in different environmental media. The residual characteristics of five typical veterinary antibiotics （sulfadiazine, SDZ； doxycycline, DOX； oxytetracycline, OTC； tetracycline, TC； and chlortetracycline, CTC） in different environmental media and their effects on environmental microbial diversity were preliminarily discussed by taking an ecological farm and a seven-year long-term experimental field in Bishan District of Chongqing as the research object. The results showed that the content of oxytetracycline in chicken manure was the highest （17.75-18.80 μg·kg^-1）, the content of doxycycline in soil was the highest （2.00-2.55 μg·kg^-1）, and the concentration of chlortetracycline in water was the highest （13.77-21.10 μg·L^-1）. During the sampling time, the total antibiotics in soil and chicken manure changed little. The five antibiotics in the water had high ecological risks. The five antibiotics significantly affected the microbial diversity in the environmental media. The dominant bacteria in the soil were Proteobacteria and Actinobacteria, and the dominant bacteria in water were Proteobacteria and Bacteroidetes.