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臭氧氧化处理不同抗生素耐药靶点耐药菌方面取得重要进展。研究成果以《Mechanism of antibiotic resistance spread during sub-lethal ozonation of antibiotic-resistant bacteria with different resistance targets》(https://doi.org/10.1016/j.watres.2024.121837)为题，于近期发表在Water Research (2024, 259, 121837)期刊上。论文的主要作者为我院硕士生白丛林和博士后蔡仪威等，通讯作者为安太成教授，广东工业大学为论文的单位。

论文网址：https://doi.org/10.1016/j.watres.2024.121837

水生环境中抗生素耐药菌(ARB)的和抗生素耐药基因(ARGs)的增加与传播极大地影响了环境和人类健康。因此，有必要了解亚致死浓度臭氧氧化对ARB和ARGs的作用机制，并制定解决这一问题的措施。本研究旨在阐明不同抗生素耐药靶点(包括细胞壁、细胞膜和蛋白质)的ARB在亚致死臭氧氧化过程中的抗生素耐药性传播机制。结果表明：暴露于0 ~ 1.0 mg/L臭氧10 分钟后，ARB的接合转移和转化频率增加。与未受臭氧刺激的对照组相比，亚致死臭氧氧化处理的ARB E. coli DH5α (CTX)、E. coli DH5α (MCR)和E. coli DH5α (GEN)的接合转移频率分别提高了1.35 ~ 2.02倍、1.13 ~ 1.58倍和1.32 ~ 2.12倍； E. coli DH5α (MCR)和E. coli DH5α (GEN) ARB的转化频率也分别提高了1.49 ~ 3.02倍和1.45 ~ 1.92倍。在添加靶点抑制剂后，靶向细胞壁和细胞膜合成的ARB E. coli DH5α (CTX)和E. coli DH5α (MCR)的接合转移频率分别降低了0.59 ~ 0.75倍和0.43 ~ 0.76倍，而靶向蛋白质合成的ARB E. coli DH5α (GEN)的接合转移频率增加了1.00 ~ 1.38倍。此外，在添加靶点抑制剂后，靶向细胞膜和蛋白质的ARB E. coli DH5α (MCR)和E. coli DH5α (GEN)的转化频率分别降低了0.76 ~ 0.89倍和0.69 ~ 0.78倍。不同的ARB的细胞形态、细胞膜通透性、活性氧水平和抗氧化酶酶活均随臭氧浓度的变化而变化。当细菌暴露于亚致死臭氧时，大多数调控抗生素耐药靶点的相关基因表达上调，进一步证实了靶点基因在不同耐药靶点细菌的失活中起着至关重要的作用。该研究成果将有助于指导臭氧氧化对细菌灭活的实际应用，为臭氧氧化处理水生环境中ARB和ARGs提供更详细的理论和技术支撑。

英文摘要：

The increase and spread of antibiotic-resistant bacteria (ARB) in aquatic environments and the dissemination of antibiotic resistance genes (ARGs) greatly impact environmental and human health. It is necessary to understand the mechanism of action of ARB and ARGs to formulate measures to solve this problem. This study aimed to determine the mechanism of antibiotic resistance spread during sub-lethal ozonation of ARB with different antibiotic resistance targets, including proteins, cell walls, and cell membranes. ARB conjugation and transformation frequencies increased after exposure to 0− 1.0 mg/L ozone for 10 min. During sub-lethal ozonation, compared with control groups not stimulated by ozone, the conjugative transfer frequencies of E. coli DH5α (CTX), E. coli DH5α (MCR), and E. coli DH5α (GEN) increased by 1.35− 2.02, 1.13− 1.58, and 1.32− 2.12 times, respectively; the transformation frequencies of E. coli DH5α (MCR) and E. coli DH5α (GEN) increased by 1.49− 3.02 and 1.45− 1.92 times, respectively. When target inhibitors were added, the conjugative transfer frequencies of antibiotics targeting cell wall and membrane synthesis decreased 0.59− 0.75 and 0.43− 0.76 times, respectively, while that for those targeting protein synthesis increased by 1− 1.38 times. After inhibitor addition, the transformation frequencies of bacteria resistant to antibiotics targeting the cell membrane and proteins decreased by 0.76− 0.89 and 0.69− 0.78 times, respectively. Cell morphology, cell membrane permeability, reactive oxygen species, and antioxidant enzymes changed with different ozone concentrations. Expression of most genes related to regulating different antibiotic resistance targets was up-regulated when bacteria were exposed to sub-lethal ozonation, further confirming the target genes playing a crucial role in the inactivation of different target bacteria. These results will help guide the careful utilization of ozonation for bacterial inactivation, providing more detailed reference information for ozonation oxidation treatment of ARB and ARGs in aquatic environments.

项目资助：本研究受到国家自然科学基金项目(42330702, 42077333, 42122056和22076030)，粤桂联合基金重点项目 (2020B1515420002)的联合资助。