摘要

      土壤是抗生素抗性基因（ARGs）的重要贮存库，但对其在农田土壤中的分布及其主要驱动力的研究还很少。本文采用高通量定量PCR方法，对我国2200公里样带105个农田土壤（种植玉米、花生或大豆）的ARGs模式进行了研究。共检测到204个ARGs，其中华中地区的ARGs多样性高于东北和华南地区。最丰富（前50%）和高度共享（存在于>50%的样本中）的arg被认为是核心耐药基因，主要由oprJ、acrA-05和acrA-04等多药耐药基因控制。回归分析表明，总ARGs和核心抗性的相对丰度均与移动遗传因子（MGEs）有显著关系。地膜消耗量、土壤重金属等人为因素与ARGs多样性有较好的相关性。结构方程模型分析进一步说明人为因素是形成ARGs模式的主要因素。这些发现强调了人类活动在形成农田土壤抗药性方面的重要性，为通过食物链减少ARGs向人类传播提供了潜在的管理策略。

      Soil is a vital reservoir of antibiotic resistance genes (ARGs), but we still know little about their distribution in cropland soils and the main driving forces. Here we performed an investigation for ARGs patterns in 105 cropland soils (planted with maize, peanut or soybean) along a 2, 200 km transect in China using high-throughput quantitative PCR approaches. Totally, 204 ARGs were detected, with a higher diversity found in central China than that in northeast and south China. The most abundant (top 50%) and highly shared (present in >50% samples) ARGs regarded as core resistome were dominated by multidrug resistance genes such as oprJ, acrA-05 and acrA-04. Regressive analyses revealed that the relative abundance of total ARGs and core resistome both had significant relationships with mobile genetic elements (MGEs). Anthropogenic factors including the consumption of plastic films and soil properties including heavy metals showed good correlations with the diversity of ARGs. Structural equation modelling analysis further explained that anthropogenic factors were the main forces shaping the ARGs patterns. These findings highlight the importance of human activities in shaping soil antibiotic resistome in the croplands, providing potential management strategies to mitigate the dissemination of ARGs to humans via food chain.

       https://www.sciencedirect.com/science/article/pii/S0048969719364149