摘要
      可以编码细菌耐药性特征的抗生素耐药性基因（ARGs）遍布整个环境。虽然通常很难辨别它们的起源，但它们的流行率和多样性取决于许多因素，其中之一是它们暴露于土壤中的潜在有毒元素（PTE，即金属和准金属）。在这里，我们研究了环境ARGs和可移动遗传元素（MGE）如何与英格兰东北部农村和城市土壤中不同PTE（总PTE与可交换和碳酸盐结合的PTE）的相对生物利用度相关。农村地区ARG的平均相对丰度在3个对数范围内变化（7.24×10−7至1.0×10−4基因/16S rRNA），城市地区的ARG相对丰度变化四个数量级（1.75×10−6至2.85×10−2基因/16S r RNA）。虽然β-内酰胺和氨基糖苷类耐药基因分别在农村和城市地区占主导地位，但非特异性ARG（也称为多药耐药基因）在城市地区明显更丰富（p<0.05）。城市地区的PTE总浓度和可交换形式也高于农村地区，而农村地区的碳酸盐结合形式更高。PTEs、ARGs和MGE之间存在显著的正Spearman相关性，尤其是在生物可利用的PTE组分和城市地区。这项研究发现ARGs和铍（Be）之间存在显著的正相关性，而这一点此前尚未报道。总的来说，我们的研究结果表明，PTE的生物利用度在解释土壤环境中ARG的相对选择方面很重要，在未来的共同选择和ARG暴露研究中必须考虑这一点。
Abstract
Antibiotic resistance genes (ARGs) that can encode resistance traits in bacteria are found across the environment. While it is often difficult to discern their origin, their prevalence and diversity depends on many factors, one of which is their exposure to potentially toxic elements (PTE, i.e., metals and metalloids) in soils. Here, we investigated how ambient ARGs and mobile genetic elements (MGEs) relate to the relative bioavailability of different PTEs (total versus exchangeable and carbonate-bound PTE) in rural and urban soils in northeast England. The average relative abundances of ARGs in rural sites varied over a 3-log range (7.24 × 10−7 to 1.0 × 10−4 genes/16S rRNA), and relative ARG abundances in urban sites varied by four orders of magnitude (1.75 × 10−6 to 2.85 × 10−2 genes/16S rRNA). While beta-lactam and aminoglycoside resistance genes dominated rural and urban sites, respectively, non-specific ARGs, also called multidrug-resistance genes, were significantly more abundant in urban sites (p < 0.05). Urban sites also had higher concentrations of total and exchangeable forms of PTE than rural sites, whereas rural sites were higher in carbonate-bound forms. Significant positive Spearman correlations between PTEs, ARGs and MGEs were apparent, especially with bioavailable PTE fractions and at urban sites. This study found significant positive correlations between ARGs and beryllium (Be), which has not previously been reported. Overall, our results show that PTE bioavailability is important in explaining the relative selection of ARGs in soil settings and must be considered in future co-selection and ARG exposure studies.

https://www.sciencedirect.com/science/article/pii/S0048969722046101