摘要

黑土（软土）是我国重要的粮食生产和食品安全土壤资源。为了保持土壤肥力，在黑土中普遍使用动物粪便。然而，这一应用对中国黑土抗生素抗性基因（ARGs）的丰度和多样性的影响尚不清楚。本文采用高通量定量PCR技术，对我国东北地区4个不同施肥方法长期试验站和2个试验点的72份土壤样品进行了ARGs检测。结果表明，共检测到178个ARGs，其中包括可移动基因元件（MGEs），并且随着施肥量的增加，ARGs的多样性和丰度显著增加。此外，我们发现ARGs相对丰度与MGEs呈显著正相关（P<0.0001），提示水平基因转移可能对ARGs的传播产生潜在影响。此外，aadA-1-01和mexF两个基因分别对应编码对氨基糖苷类药物和多药耐药类的抗性，被认为是评估其他共现ARGs丰度的指标。这些研究结果为研究东北黑土抗生素抗性提供了新的思路，同时也强调了施用有机肥所带来的环境风险不容忽视。

Black soils (Mollisols) are important soil resources for crop production and maintain food safety in China. For keeping soil fertility, the application of animal manure is commonly practiced in black soils. However, the impact of this application on abundance and diversity of antibiotic resistance genes (ARGs) in black soils of China remains unclear. Here, we surveyed the profiles of ARGs in 72 soil samples collected from four long-term experimental stations with different fertilization regimes and from open farmlands in two sites across northeast China using high-throughput quantitative PCR. Results showed that a total of 178 ARGs including mobile genetic elements (MGEs) were detected, and the diversity and abundance of ARGs were significantly increased with manure application. Additionally, the finding of a significant positive correlation between relative abundance of ARGs and MGEs (P <  0.0001), suggesting that horizontal gene transfer may potentially impact the transmission of ARGs. Furthermore, two genes aadA-1-01 and mexF, encoding resistance to aminoglycoside and multidrug, respectively, were recognized as indicators to estimate the abundance of other co-occurring ARGs. These findings provided insights into the soil resistome in black soils of northeast China and also highlighted the environmental risks caused by manure application should not be ignored.

https://www.sciencedirect.com/science/article/abs/pii/S0304389419311707