Abstract：
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.
摘要：
抗生素抗性细菌（ARB）在水生环境中的增加和传播以及抗生素抗性基因（ARG）的传播极大地影响了环境和人类健康。有必要了解ARB和ARGs的作用机理，以制定解决这一问题的措施。本研究旨在确定不同抗生素抗性靶标的ARB亚致死臭氧化过程中抗生素抗性传播的机制。包括蛋白质，细胞壁,和细胞膜。暴露于0-1.0mg/L臭氧10分钟后，ARB的结合和转化频率增加。在亚致死臭氧化过程中,与未受臭氧刺激的对照组相比，大肠杆菌DH5α(CTX)的共轭转移频率，大肠杆菌DH5α（MCR），大肠杆菌DH5α(GEN)分别增加1.35-2.02、1.13-1.58和1.32-2.12倍,大肠杆菌DH5α(MCR)和大肠杆菌DH5α(GEN)的转化频率分别提高了1.49-3.02和1.45-1.92倍,分别。当添加目标抑制剂时，靶向细胞壁和膜合成的抗生素的接合转移频率降低了0.59-0.75和0.43-0.76倍，分别,而那些靶向蛋白质的合成增加了1-1.38倍。加入抑制剂后,以细胞膜和蛋白质为目标的抗生素耐药细菌的转化频率降低了0.76-0.89和0.69-0.78倍，分别。细胞形态学,细胞膜通透性，活性氧，和抗氧化酶随着不同的臭氧浓度而变化。当细菌暴露于亚致死臭氧化时，与调节不同抗生素抗性靶标相关的大多数基因的表达被上调，进一步证实了靶基因在不同靶细菌的失活中起着至关重要的作用。这些结果将有助于指导仔细利用臭氧化进行细菌灭活，为水生环境中ARB和ARGs的臭氧氧化处理提供更详细的参考信息。
