摘要
      全球分布的蚯蚓影响土壤化合物的组成、微生物群落结构以及抗生素抗性基因（ARGs）。与周围环境相比，蚯蚓肠道是一个更简单的环境，当土壤通过它时，它可以过滤掉微生物。然而，人们对蚯蚓如何影响ARGs在土壤中的传播知之甚少，对微生物-微生物相互作用与ARGs之间的关系仍缺乏了解。在这里，我们设计了一个添加蚯蚓的微观实验，并基于扩增子测序确定了细菌和真菌群落组成。我们还使用高通量qPCR检测了蚯蚓肠道和土壤中的移动遗传元件（MGE）和ARGs。结果表明，肠道和土壤的细菌、真菌和ARG模式存在显著差异。蚯蚓通过影响细菌群落和土壤特性间接影响了土壤中ARGs的模式，而细菌群落和土地特性在ARGs和MGE的分布中起着关键作用。蚯蚓肠道中MGEs的绝对丰度显著低于土壤中的MGEs，蚯蚓降低了土壤中MGEs的绝对丰度。蚯蚓改变了微生物的共生模式，降低了细菌的连通性，这与MGE的丰度显著正相关。这些结果突出了蚯蚓对ARGs在土壤中分布和传播的重要性。
Abstract
Globally distributed earthworms affect compositions of soil compounds, microbial community structures, as well as antibiotic resistance genes (ARGs). Compared to their surroundings, earthworm gut is a simpler environment which could filter out microbes when soil passes through it. However, little is known about how earthworms affect the dissemination of ARGs in soil, and the understanding of the relationship between microbe-microbe interactions and ARGs is still lacking. Here, we designed a microcosm experiment with earthworm addition, and determined bacterial and fungal community compositions based on amplicon sequencing. We also examined mobile genetic elements (MGEs) and ARGs in earthworm gut and soils using high-throughput qPCR. The results showed significant differences of bacterial, fungal and ARG patterns between gut and soil. Earthworms indirectly impacted the patterns of ARGs in soils by affecting bacterial communities and soil properties, which play key roles in the distribution of ARGs and MGEs. The absolute abundances of MGEs in earthworm gut were significantly lower than those in soils, and earthworms reduce the absolute abundance of MGEs in soils. Earthworms changed the microbial co-occurrence patterns, and reduced bacterial connectivity, which were significantly and positively correlated with MGE abundance. These results highlight the importance of earthworm on the distribution and dissemination of ARGs in soils.

https://www.sciencedirect.com/science/article/abs/pii/S0304389421030971