Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen 361021, China; Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg, Denmark.
Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, 1799 Jimei Road, Xiamen 361021, China.
Sci Total Environ. 2018 Apr 15;621:1224-1232. doi: 10.1016/j.scitotenv.2017.10.106. Epub 2017 Oct 18.
Antibiotic resistance genes (ARGs) are emerging environmental contaminants posing a threat to public health. Antibiotics and metals are widely used as feed additives and could consequently affect ARGs in swine gut. In this study, high-throughput quantitative polymerase chain reaction (HT-qPCR) based ARG chip and next-generation 16S rRNA gene amplicon sequencing data were analyzed using multiple statistical approaches to profile the antibiotic resistome and investigate its linkages to antibiotics and metals used as feed additives and to the microbial community composition in freshly collected swine manure samples from three large-scale Chinese pig farms. A total of 146 ARGs and up to 1.3×10 total ARG copies per gram of swine feces were detected. ARGs conferring resistance to aminoglycoside, macrolide-lincosamide-streptogramin B (MLSB) and tetracycline were dominant in pig gut. Total abundance of ARGs was positively correlated with in-feed antibiotics, microbial biomass and abundance of mobile genetic elements (MGEs) (P<0.05). A significant correlation between microbial communities and ARG profiles was observed by Procrustes analysis. Network analysis revealed that Bacteroidetes and Firmicutes were the most dominant phyla co-occurring with specific ARGs. Partial redundancy analysis indicated that the variance in ARG profiles could be primarily attributed to antibiotics and metals in feed (31.8%), gut microbial community composition (23.3%) and interaction between feed additives and community composition (16.5%). These results suggest that increased levels of in-feed additives could aggravate the enrichment of ARGs and MGEs in swine gut.
抗生素耐药基因（ARGs）作为新兴的环境污染物，对公共健康构成了威胁。抗生素和金属被广泛用作饲料添加剂，因此可能会影响猪肠道中的 ARGs。在这项研究中，采用高通量定量聚合酶链反应（HT-qPCR）基于 ARG 芯片和下一代 16S rRNA 基因扩增子测序数据，通过多种统计方法分析了抗生素耐药组，研究了其与作为饲料添加剂使用的抗生素和金属之间的联系，以及从三个大型中国养猪场新鲜采集的猪粪样本中微生物群落组成之间的联系。共检测到 146 种 ARGs 和高达每克猪粪便 1.3×10 的总 ARG 拷贝数。猪肠道中主要存在对抗生素（aminoglycoside）、大环内酯-林可酰胺-链霉菌素 B（macrolide-lincosamide-streptogramin B，MLSB）和四环素（tetracycline）具有抗性的 ARGs。ARGs 的总丰度与饲料中的抗生素、微生物生物量和移动遗传元件（mobile genetic elements，MGEs）的丰度呈正相关（P<0.05）。Procrustes 分析表明，微生物群落与 ARG 图谱之间存在显著相关性。网络分析显示，拟杆菌门（Bacteroidetes）和厚壁菌门（Firmicutes）是与特定 ARGs 最相关的两个优势门。偏冗余分析表明，ARG 图谱的方差主要归因于饲料中的抗生素和金属（31.8%）、肠道微生物群落组成（23.3%）以及饲料添加剂和群落组成之间的相互作用（16.5%）。这些结果表明，饲料中添加物水平的增加可能会加剧猪肠道中 ARGs 和 MGEs 的富集。
