State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
Water Res. 2017 Nov 1;124:259-268. doi: 10.1016/j.watres.2017.07.061. Epub 2017 Jul 24.
Large amounts of antibiotics are currently used in livestock breeding, which is the main driving factor contributing to the occurrence, spread and proliferation of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in the environment. In this study, high-throughput sequencing based metagenomic approaches were employed to characterize the tempo-spacial changes of antibiotic resistome, bacterial community and their correlations in pig farming wastewater and its receiving river. A total of 194 ARG subtypes within 14 ARG types were detectable in all the samples, and their total relative abundance increased in the river water after receiving wastewater discharge, while decreased in the downstream river water. Network analysis showed that 25.26% ARGs within the same type or among the different types showed higher incidences of non-random co-occurrence. The wastewater discharge evidently increased bacterial diversity and induced bacterial community shift in the receiving river water. The genera of Treponema, Prevotella, Pseudomonas, Bacteroides, Oscillibacter and Acholeplasma dominated in the wastewater samples and almost disappeared in the receiving river water, but bacterial pathogens Clostridium difficile and Arcobacter butzleri still occurred in the receiving water. Correlation analysis and host analysis consistently showed that the changes in the abundances of several key genera like Prevotella and Treponema were significantly and positively correlated with the antibiotic resistome alteration. Variation partitioning analysis indicated that bacterial community played a more important role in the resistome alteration than mobile genetic elements. This study may help to understand the correlations among antibiotic resistome, microbiota and environmental conditions in the wastewater-receiving river water.
目前，大量抗生素被用于畜牧业养殖，这是导致环境中抗生素耐药菌（ARB）和抗生素耐药基因（ARGs）发生、传播和扩散的主要驱动因素。在这项研究中，我们采用基于高通量测序的宏基因组学方法来描述养猪废水中抗生素耐药组、细菌群落及其相关性的时空变化，并研究其在受纳河流中的变化情况。在所有样本中，共检测到 194 种 ARG 亚型，属于 14 种 ARG 类型，所有样本中均能检测到。在受纳河流接受废水排放后，ARG 的总相对丰度增加，而在下游河水中则减少。网络分析显示，同一类型或不同类型的 ARG 中有 25.26%的 ARG 具有较高的非随机共现发生率。废水排放明显增加了细菌多样性，并导致受纳河水中的细菌群落发生变化。在废水样本中，梅毒螺旋体、普雷沃氏菌、假单胞菌、拟杆菌、颤螺菌和无壁菌属等属占主导地位，而在受纳河水中几乎消失，但在受纳水中仍存在艰难梭菌和弯曲杆菌等细菌病原体。相关性分析和宿主分析一致表明，一些关键属（如普雷沃氏菌和梅毒螺旋体）丰度的变化与抗生素耐药组的变化呈显著正相关。变异分解分析表明，细菌群落对耐药组变化的影响比可移动遗传元件更为重要。本研究有助于理解抗生素耐药组、微生物群和受纳河水中环境条件之间的相关性。
