Key Laboratory of Urban Environment and Health, Ningbo Urban Environment Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
School of Agriculture, Food and Ecosystem Sciences, Faculty of Science, The University of Melbourne, Parkville, Victoria 3010, Australia.
Environ Sci Technol. 2024 Aug 6;58(31):13961-13972. doi: 10.1021/acs.est.4c03812. Epub 2024 Jul 22.
Earthworms are critical in regulating soil processes and act as filters for antibiotic resistance genes (ARGs). Yet, the geographic patterns and main drivers of earthworm gut ARGs remain largely unknown. We collected 52 earthworm and soil samples from arable and forest ecosystems along a 3000 km transect across China, analyzing the diversity and abundance of ARGs using shotgun metagenomics. Earthworm guts harbored a lower diversity and abundance of ARGs compared to soil, resulting in a stronger distance-decay rate of ARGs in the gut. Greater deterministic assembly processes of ARGs were found in the gut than in soil. The earthworm gut had a lower frequency of co-occurrence patterns between ARGs and mobile genetic elements (MGEs) in forest than in arable systems. Viral diversity was higher in the gut compared to soil and was negatively correlated with bacterial diversity. Bacteria such as and were potential hosts of both viruses and ARGs. Viruses had negative effects on the diversity and abundance of ARGs, likely due to the lysis on ARG-bearing bacteria. These findings provide new insights into the variations of ARGs in the earthworm gut and highlight the vital role of viruses in the regulation of ARGs in the soil ecosystem.
蚯蚓在调节土壤过程中起着关键作用，并充当抗生素抗性基因（ARGs）的过滤器。然而，蚯蚓肠道 ARGs 的地理格局和主要驱动因素在很大程度上仍然未知。我们从中国 3000 公里长的横断带上的耕地和森林生态系统中收集了 52 个蚯蚓和土壤样本，使用 shotgun 宏基因组学分析了 ARGs 的多样性和丰度。与土壤相比，蚯蚓肠道中 ARGs 的多样性和丰度较低，导致肠道中 ARGs 的距离衰减率更强。与土壤相比，肠道中 ARGs 的确定性组装过程更强。与耕地系统相比，森林系统中蚯蚓肠道中 ARGs 与移动遗传元件（MGEs）之间的共现模式频率较低。与土壤相比，肠道中的病毒多样性更高，与细菌多样性呈负相关。和 等细菌可能是病毒和 ARGs 的共同宿主。病毒对 ARGs 的多样性和丰度有负面影响，可能是由于 ARG 携带细菌的裂解。这些发现为蚯蚓肠道中 ARGs 的变化提供了新的见解，并强调了病毒在土壤生态系统中调节 ARGs 方面的重要作用。
