摘要

    黑土（Mollisol）是我国农作物生产和食品安全的重要土壤资源。为了保持土壤肥力，通常在黑土中施用动物粪便。然而，这种应用对中国黑土中抗生素抗性基因（ARGs）的丰度和多样性的影响尚不清楚。在这里，我们使用高通量定量 PCR 调查了从具有不同施肥制度的四个长期试验站和中国东北两个地点的开放农田收集的 72 个土壤样品中 ARGs 的概况。结果表明，共检测到包括移动遗传元件（MGEs）在内的178个ARGs，随着施肥，ARGs的多样性和丰度显着增加。此外，发现ARGs和MGEs的相对丰度之间存在显着正相关（P < 0.0001），表明水平基因转移可能会影响ARGs的传播。此外，分别编码对氨基糖苷类和多药耐药的两个基因 aadA-1-01 和 mexF 被认为是估计其他共存 ARG 丰度的指标。这些发现提供了对中国东北黑土土壤抗性组的见解，也强调了施肥造成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