Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development (Department of Education), School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Key Laboratory of City Cluster Environmental Safety and Green Development (Department of Education), School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
Water Res. 2024 Aug 1;259:121837. doi: 10.1016/j.watres.2024.121837. Epub 2024 May 24.
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.
耐抗生素细菌（ARB）在水生环境中的增加和传播以及抗生素耐药基因（ARGs）的传播，对环境和人类健康造成了巨大影响。了解 ARB 和 ARGs 的作用机制对于制定解决这一问题的措施非常必要。本研究旨在确定不同抗生素耐药靶标（包括蛋白质、细胞壁和细胞膜）的 ARB 在亚致死臭氧化过程中抗生素耐药性传播的机制。暴露于 0-1.0 mg/L 臭氧 10 分钟后，ARB 的接合和转化频率增加。在亚致死臭氧化过程中，与未受臭氧刺激的对照组相比，E. coli DH5α（CTX）、E. coli DH5α（MCR）和 E. coli DH5α（GEN）的接合转移频率分别增加了 1.35-2.02、1.13-1.58 和 1.32-2.12 倍；E. coli DH5α（MCR）和 E. coli DH5α（GEN）的转化频率分别增加了 1.49-3.02 和 1.45-1.92 倍。添加靶标抑制剂后，针对细胞壁和膜合成的抗生素的接合转移频率分别降低了 0.59-0.75 和 0.43-0.76 倍，而针对蛋白质合成的抗生素的接合转移频率则增加了 1-1.38 倍。添加抑制剂后，针对细胞膜和蛋白质的抗生素耐药菌的转化频率分别降低了 0.76-0.89 和 0.69-0.78 倍。不同臭氧浓度下，细胞形态、细胞膜通透性、活性氧和抗氧化酶发生变化。当细菌暴露于亚致死臭氧化时，与调节不同抗生素耐药靶标的大多数基因的表达上调，进一步证实了靶基因在不同靶标细菌失活中发挥关键作用。这些结果将有助于指导臭氧用于细菌灭活的谨慎利用，为臭氧氧化处理水生环境中的 ARB 和 ARGs 提供更详细的参考信息。
