摘要
      细菌结合是抗生素抗性基因（ARGs）在环境中传播的最显著方式之一。天然胶体矿物和细菌之间的界面相互作用可以改变细菌的有效接触，从而影响ARGs的结合。了解胶体矿物的核心成分铁矿物对ARGs结合的影响，有助于评估和干预ARGs传播的风险。通过三个选定的铁矿物扰动实验，发现低浓度的铁矿物（即5−100 mg L−1）对携带卡那霉素抗性基因的质粒的偶联转移促进了1.35−3.91倍，但在高浓度（即1000−2000 mg L−1）时被抑制为0.10−0.22倍。结合物的发生与每单位质量矿物粘附的细菌数量高度相关，因此矿物细菌粘附模式的切换决定了ARGs的结合物转移是被促进还是被抑制。此外，根据粘附对结合的物理化学和生理影响，建立了一个统一的模型，可用于估计不同铁矿物对结合的临界抑制浓度。我们的研究结果表明，天然胶体矿物在通过界面相互作用防止ARGs在环境中传播方面具有巨大的应用潜力。
Abstract
Bacterial conjugation is one of the most prominent ways for antibiotic resistance genes (ARGs) transmission in the environment. Interfacial interactions between natural colloidal minerals and bacteria can alter the effective contact of bacteria, thereby affecting ARGs conjugation. Understanding the impact of iron minerals, a core component of colloidal minerals, on ARGs conjugation can help assess and intervene in the risk of ARGs transmission. With three selected iron minerals perturbation experiments, it was found that the conjugative transfer of plasmid that carried kanamycin resistance gene was 1.35 − 3.91-fold promoted by low concentrations of iron minerals (i.e., 5 − 100 mg L−1), but inhibited at high concentrations (i.e., 1000 − 2000 mg L−1) as 0.10 − 0.22-fold. Conjugation occurrence was highly relevant to the number of bacteria adhering per unit mass of mineral, thus switch in the adhesion modes of mineral-bacterial determined whether the conjugate transfer of ARGs was facilitated or inhibited. In addition, a unified model was formularized upon the physicochemical and physiological effects of adhesion on conjugation, and it can be used in estimating the critical inhibitory concentration of different iron minerals on conjugation. Our findings indicate natural colloidal minerals have great potential for applications in preventing the environmental propagation of ARGs through interfacial interactions.

https://www.sciencedirect.com/science/article/abs/pii/S0304389422006781