摘要

现代养猪场通常包含几种动物类型，并广泛依赖饲料添加剂，包括抗生素和重金属，以增加动物的生长。尽管如此，作为环境中抗生素抗性基因（ARG）的重要储存库，来自养猪场的每种动物类型的ARG排放尚未被表征。本研究的目的是确定哪种动物对中国典型养猪场的ARG排放对环境的贡献最大。结果表明，金霉素（CTC），铜和锌是典型的饲料添加剂，饲料和猪粪中抗生素和重金属的浓度在育苗猪（NP）中普遍高于其他动物类型，而基因拷贝妊娠母猪（GS）的ARG是最丰富的。与其他动物类型相比，GS每人每天释放大部分抗生素，ARG和移动遗传因子（MGE）。原料为10,000头猪的典型猪场每天可释放约4.0±1.3×1017个ARG基因拷贝，关于繁殖率和肥料生产系数，生长肥育猪（GFP）释放出大部分ARG和抗生素，而妊娠母猪（GS）释放了大部分MGE。不同动物类型中ARG的不同分布主要取决于壁炉试验和部分冗余分析（pRDA）反映的微生物群落组成的差异。猪粪中的主要门是Firmicutes和Bacteroidetes，但Proteobacteria，Bacteroidetes和Spirochaetae在塑造ARGs谱中起主导作用。抗生素和重金属可以产生和维持ARGs谱，而ARG的增殖和传播可能主要归因于猪粪中的微生物群落。

Modern swine farms generally contain several animal types and rely extensively on the feed additives, including antibiotics and heavy metals, to augment animal growth. Nonetheless, as an important reservoir of antibiotic resistance genes (ARGs) in the environment, the ARGs emission of each animal type from swine farms has not been characterized. The goal of this study is to determine which animal type contributes the most to the ARGs emission into the environment in typical swine farms of China. Results showed that chlortetracycline (CTC), Cu and Zn were the typical feed additives, and the concentrations of antibiotics and heavy metals in the feed and swine manure were generally higher in nursery pigs (NP) than other animal types, while the gene copies of ARGs from gestation sows (GS) were the most abundant. GS released the most of antibiotics, ARGs and mobile genetic elements (MGEs) per head per day compared to other animal types. A typical swine farms with the feedstock of 10,000 pigs could release about 4.0 ± 1.3 × 1017 gene copies of ARGs per day, and concerning the breeding ratio and manure production coefficient, growing and fattening pigs (GFP) released the most of ARGs and antibiotics, whereas gestation sows (GS) released the most of MGEs. The different distribution of ARGs in different animal types was mainly determined by the discrepancy of microbial community composition reflected by mantel test and partial redundancy analysis (pRDA). The dominant phylum in swine manure were Firmicutes and Bacteroidetes, but Proteobacteria, Bacteroidetes and Spirochaetae played the dominant role in shaping the ARGs profiles. Antibiotics and heavy metals could have generated and maintained the ARGs profiles, whereas the proliferation and spread of ARGs could be mainly attributed to microbial community in swine manure.

https://www.ncbi.nlm.nih.gov/pubmed/30577014