近日，广东工业大学环境健康与污染控制研究院、环境科学与工程学院安太成教授团队在亚致死光催化胁迫下抗生素抗性基因(ARG)的转化增强方面取得最新研究进展，研究成果以《Enhanced transformation mechanisms of antibiotic resistance genes in water under the stress of sub-lethal photocatalysis》为题发表在Biocontaminant (2025, 1：e017)期刊上。论文的第一作者为博士生孙彤，主要作者还包括硕士毕业生吉昊和博士后蔡仪威等，通讯作者为安太成教授。该研究主要关注亚致死光催化胁迫下水环境中ARG的转化增强的现象及其相关机制，阐明了亚致死性压力应激情况下ARG转化的频率不仅取决于亚致死性压力的持续时间，还取决于受体细菌的初始浓度以及培养温度，揭示了氧化应激反应的激活、细胞膜通透性的增加以及细胞内Ca²⁺的积累是促进ARG转化的主要因素。本研究的发现揭示了亚致死性环境压力与ARG转化之间的关系，有助于更好地理解ARG在水环境中的传播。

抗生素抗性基因(ARG)在水环境中的传播引起了广泛关注。转化是基因水平转移的一种方式。此外，细菌在环境中可能会受到亚致死性压力应激的影响，但亚致死性压力对ARG转化的影响及相关机制尚不明确。本研究采用亚致死光催化(sub-PC)模拟水体中耐药细菌未被完全消毒的状态下，本研究选择两种抗生素敏感菌(ASB)(E. coli DH5α和E. coli HB101)作为受体细菌，将其分别与携带氨苄青霉素耐药基因(amp)的pUC19质粒一起构建不同的基因转化系统，旨在研究亚致死压力应激对ARG转化的影响。同时，本研究通过检测受体细菌在sub-PC处理前后的生理特征变化，揭示了亚致死胁迫下ARG转化的机制。结果显示：sub-PC处理使ARG的转化频率提高了3.0-4.5倍。在暴露于亚致死性压力应激时，约10%的ASB(作为受体株)仍保持活性，为ARG转化提供了一定的转化基础。与此同时ASB的细胞内活性氧(ROS)水平上升，最高提升3-4倍。并且ASB的抗氧化应激系统也被激活，具体表现为过氧化氢酶(CAT)和超氧化物歧化酶(SOD)水平升高。此外，ASB的细胞膜通透性增加，细胞内Ca²⁺出现积累，胞内Ca²⁺水平最高增长了近4倍。这些变化证明并促进了水环境中ARG转化频率的增加。此外，ASB的细胞内ATP含量降低，这会导致细胞内Ca²⁺积累，从而间接促进了ARG转化的发生。相关基因表达的检测也证实了这些发现。总之，本研究证明亚致死性压力已经在一定程度上促进了细菌ARG的转化，从而增加了抗生素耐药细菌(ARB)在水环境中传播的风险。本研究的发现有助于更好地理解ARG在水生环境中的传播与健康风险的评估。

网址：https://www.maxapress.com/article/doi/10.48130/biocontam-0025-0017

图文摘要：

英文题目：Enhanced transformation mechanisms of antibiotic resistance genes in water under the stress of sub-lethal photocatalysis

英文摘要：The spread of antibiotic resistance genes (ARGs) in aquatic environments has attracted considerable attention. Transformation is one form of horizontal gene transfer. Bacteria may be subject to sub-lethal stress in the environment, but the impact of sub-lethal stress on ARG transformation and related mechanisms remains unclear. In this study, sub-lethal photocatalysis (sub-PC) was employed to simulate the condition of incomplete water disinfection. Two antibiotic-sensitive bacteria (ASB) (E. coli DH5α and E. coli HB101) were selected as recipient bacteria, combined with the pUC19 plasmid carrying the ampicillin resistance gene (amp), to build different transformation systems, aiming to investigate the impact of sub-lethal stress on the transformation of ARGs. Meanwhile, by detecting the physiological characteristics of recipient bacteria, before and after sub-PC treatment, this study reveals the mechanism of ARG transformation under sub-lethal treatment. The results show that sub-PC treatment increased the transformation frequency of the amp gene by 3.0-4.5 times. Upon exposure to sub-lethal stress, nearly 10% ASB (as recipient strains) remained viable, providing the basis for ARG transformation. Concurrently, the intracellular reactive oxygen species (ROS) levels in ASB increased, reaching the highest level 3-4 times. The antioxidant stress system was also activated, as evidenced by increased levels of CAT and SOD. Furthermore, bacterial membrane permeability was validated, and intracellular Ca²⁺ accumulation was observed in bacterial cells (the highest increase reaching nearly four times). These are all the reasons why the transformation frequency of ARG increased in the aquatic environment. Moreover, the decrease in intracellular ATP content indirectly facilitated the occurrence of ARG transformation by causing intracellular Ca²⁺ accumulation. Detection of the expression of the related gene also confirmed these findings. In summary, exposure to sub-lethal stressors in bacteria promotes the transformation of ARGs, thereby increasing the risk of spread of antibiotic-resistant bacteria (ARB) in aquatic environments. The results obtained in this work contribute to a better understanding of the dissemination of ARGs in aquatic environments.