摘要

      饮用水系统中抗生素耐药基因（ARGs）的广泛出现危害着人类健康，并可能因其在微生物群中的水平基因转移（HGT）而加剧。在我们之前的研究中，细菌从生物活性炭（BAC）生物膜中产生的群体感应（QS）分子被证明会影响模型结合质粒RP4的转移效率。本研究进一步探讨了QS对共轭转移的影响及其机理。结果表明，从BAC生物膜中分离到的产酰基高丝氨酸内酯（AHL）细菌在ARGs的繁殖中起着重要作用。我们选择了几种群体感应抑制剂（qsi）来研究它们对AHL产生菌的影响，包括生物膜的形成和对结合转移的调节作用。此外，AHLs促进结合转移的分子机制可能与促进结合相关基因的mRNA表达有关。我们还发现QSIs可以通过下调共轭相关基因来抑制共轭转移。我们相信这是对AHLs促进和QSIs抑制ARGs共轭转移机制的第一次有见地的探索。这些结果为饮用水系统中的精氨酸污染控制提供了创造性的见解，包括在生物活性炭处理过程中阻断QS。

      The widespread emergence of antibiotic resistance genes (ARGs) in drinking water systems endangers human health, and may be exacerbated by their horizontal gene transfer (HGT) among microbiota. In our previous study, Quorum sensing (QS) molecules produced by bacteria from biological activated carbon (BAC) biofilms were demonstrated to influence the transfer efficiency of a model conjugative plasmid, here RP4. In this study, we further explored the effect and mechanism of QS on conjugation transfer. The results revealed that Acyl-homoserine lactones producing (AHL-producing) bacteria isolated from BAC biofilm play a role in the propagation of ARGs. We selected several quorum sensing inhibitors (QSIs) to study their effects on AHL-producing bacteria, including the formation of biofilm and the regulating effect on conjugation transfer. In addition, the possible molecular mechanisms for AHLs that promote conjugative transfer were attributable to enhancing the mRNA expression, which involved altered expressions of conjugation-related genes. We also found that QSIs could inhibit conjugative transfer by downregulating the conjugation-relevant genes. We believe that this is the first insightful exploration of the mechanism by which AHLs will facilitate and QSIs will inhibit the conjugative transfer of ARGs. These results provide creative insight into ARG pollution control that involves blocking QS during BAC treatment in drinking water systems.

       https://www.sciencedirect.com/science/article/pii/S0048969719342196?via%3Dihub#bbb0165