摘要
      由于最近频繁发生的重大公共卫生事件，抗生素耐药性细菌（ARB）和抗生素耐药性基因（ARGs）在水中的传播越来越成为一个全球性问题。本文研究了亚致死光催化条件下ARG的水平转移机理。结果表明，当仅用亚致死性光催化诱导供体细菌时，ARGs的偶联转移频率最多增加3至6倍，而当仅诱导受体细菌时，偶联转移频率表现出抑制的趋势。然而，当供体或受体细菌被预先诱导一段特定的时间时，频率最多会增加10到22倍。此外，水平转移频率及其机制与氧化应激系统、ATP系统和相关基因的表达有关。此外，还研究了ARB细胞外质粒的可转化性及其在水平转移中的作用。结果表明，转化频率占转偶联物总数的50%，表明转化可能是ARB在水中水平转移ARG的主要模式。上述所有结果表明，亚致死性光催化将通过偶联转移和转化途径增加ARG水平基因转移的频率，从而增加ARB在水生环境中的风险。
Abstract
The spread of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in water is increasingly becoming a worldwide problem due to frequent recent major public health events. Herein, the horizontal ARG transfer mechanisms were studied under sub-lethal photocatalysis. The results show that ARGs had at most a 3- to 6-fold increase in the conjugative transfer frequency when only donor bacteria were induced with sub-lethal photocatalysis, while the frequency exhibited a trend toward inhibition when only the recipient bacteria were induced. However, when the donor or recipient bacteria were induced beforehand for a specific time, the frequency increased by a maximum of 10- to 22-fold. Moreover, the horizontal transfer frequency and its mechanism were related to the oxidative stress systems, ATP systems and the expression of related genes. Furthermore, the transformability of extracellular plasmids of the ARB and the contribution in horizontal transfer were also studied. Results show that the transformation frequency accounted for up to 50% of the total number of transconjugants, indicating that transformation might be a primary mode of horizontal ARG transfer by ARB in water. All of the above results demonstrate that sub-lethal photocatalysis will increase the frequency of horizontal gene transfer of ARGs through both conjugative transfer and the transformation pathway, which increases the risk of ARB in aquatic environments.

https://www.sciencedirect.com/science/article/abs/pii/S0043135422007618