摘要

    牲畜粪便被认为是将抗生素抗性基因（ARG）传播到环境中的重要来源，因此对公众健康构成直接威胁。尽管对肥料回用对土壤微生物群落和ARGs的影响进行了广泛研究，但对通过不同管理方法产生的微生物群落和肥料ARGs的全面表征尚不十分了解。在这里，我们分析了通过三种常规管理策略处理的微生物群落和牛粪ARG的命运：有氧堆肥，机械干燥和沉淀，采用了结合宏基因组学和元蛋白质组学的综合组学方法。综合组学研究表明，与其他两种策略处理的粪肥相比，堆肥处理的微生物群落和ARGs多样性最低。定量PCR方法显示，堆肥14天后，无论季节如何，其ARGs的丰度均降低了83％以上。此外，堆肥后，潜在的ARG宿主不动杆菌和假单胞菌占主导地位的机械干燥过程急剧减少。堆肥样品中细菌，ARG和转座酶基因tnpA-01之间的重要共生网络表明这些细菌在ARG的传播中起着重要作用。这些发现提供了在控制牲畜粪便再利用过程中控制ARG扩散的潜在策略的见解。

    Livestock manure is considered as an important source for spreading antibiotic resistance genes (ARGs) into the environment, and therefore poses a direct threat to public health. Whereas the effects of reused manure on soil microbial communities and ARGs have been studied extensively, comprehensive characterizations of microbial communities and ARGs of manure produced by different management methods are not well understood. Here, we analyzed the fate of microbial communities and ARGs of cow manure treated by three conventional management strategies: aerobic composting, mechanical drying and precipitation, applying an integrated-omics approach combining metagenomics and metaproteomics. Integrated-omics demonstrated that composted manure contained the lowest diversity of microbial community and ARGs compared with manure treated by other two strategies. Quantitative PCR methods revealed that the abundances of ARGs were reduced by over 83 % after composting for 14 days, regardless of the season. Besides, the potential ARG hosts Acinetobacter and Pseudomonas dominating mechanical drying process were sharply decreased in abundances after composting. The significant co-occurrence networks among bacteria, ARGs and transposase gene tnpA-01 in composting samples indicated the important role of these bacteria in the dissemination of ARGs. These findings offer insight into potential strategies to control the spread of ARGs during livestock manure reuse.

    https://www.sciencedirect.com/science/article/abs/pii/S0304389419318497