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, Guangdong Technology Research Center for Photocatalytic Technology Integration and Equipment Engineering, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
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, Guangdong Technology Research Center for Photocatalytic Technology Integration and Equipment Engineering, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
Water Res. 2022 Jun 30;218:118407. doi: 10.1016/j.watres.2022.118407. Epub 2022 Apr 6.
The stress response of antibiotic-resistant bacteria (ARB) and the spread of antibiotic resistance genes (ARGs) pose a serious threat to the aquatic environment and human beings. This study mainly explored the effect of the heterogeneous photocatalytic oxidation (UVA-TiO system) on the stress response mechanism of ARB with different antibiotic resistance action targets, including the cell wall, proteins, DNA, RNA, folate and the cell membrane. Results indicate that the stress response mechanism of tetracycline- and sulfamethoxazole-resistant E. coli DH5α, which targets the synthesis of protein and folate, could rapidly induce global regulators by the overexpression of relative antibiotic resistance action target genes. Different stress response systems were mediated via cross-protection mechanism, causing stronger tolerance to an adverse environment than other ARB. Moreover, the photocatalytic inactivation mechanism of bacterial cells and a graded response of cellular stress mechanism caused differences in the intensity of the stress mechanism of antibiotic resistance action targets. E. coli DH5α resistant to cefotaxime and polymyxin, targeting synthesis of the cell wall and cell membrane, respectively, could confer greater advantages to bacterial survival and higher conjugative transfer frequency than E. coli DH5α resistant to nalidixic acid and rifampicin, which target the synthesis of DNA and RNA, respectively. This new perspective provides detailed information on the practical application of photocatalytic oxidation for inactivating ARB and hampering the spreading of ARGs in the aquatic environment.
抗生素耐药菌（ARB）的应激反应和抗生素耐药基因（ARGs）的传播对水生态环境和人类健康构成了严重威胁。本研究主要探讨了不同抗生素作用靶点的 ARB （包括细胞壁、蛋白质、DNA、RNA、叶酸和细胞膜）在非均相光催化氧化（UVA-TiO2 系统）作用下的应激响应机制。结果表明，针对蛋白质和叶酸合成的四环素和磺胺甲恶唑耐药大肠杆菌 DH5α的应激响应机制可通过相对抗生素作用靶点基因的过度表达迅速诱导全局调控因子。不同的应激响应系统通过交叉保护机制进行介导，使其对不利环境的耐受性强于其他 ARB。此外，细菌细胞的光催化失活动力学和细胞应激机制的分级响应导致抗生素作用靶点的应激机制强度存在差异。分别针对细胞壁和细胞膜合成的头孢噻肟和多粘菌素耐药大肠杆菌 DH5α比分别针对 DNA 和 RNA 合成的萘啶酸和利福平耐药大肠杆菌 DH5α具有更大的生存优势和更高的接合转移频率。这一新视角为光催化氧化灭活 ARB 和阻碍 ARGs 在水生态环境中传播的实际应用提供了详细信息。
