Sun Ningyu, Gao Hu, Zhang Xinbo, Chen Zeyou, Peng Anping
Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, NO.26, Jinjing Rd, Xiqing District, Tianjin 300384, China; Joint Research Centre for Protective Infrastructure Technology and Environmental Green Bioprocess, School of Environmental and Municipal Engineering, Tianjin Chengjian University, NO.26, Jinjing Rd, Xiqing District, Tianjin 300384, China.
Tianjin Key Laboratory of Aquatic Science and Technology, School of Environmental and Municipal Engineering, Tianjin Chengjian University, NO.26, Jinjing Rd, Xiqing District, Tianjin 300384, China; Joint Research Centre for Protective Infrastructure Technology and Environmental Green Bioprocess, School of Environmental and Municipal Engineering, Tianjin Chengjian University, NO.26, Jinjing Rd, Xiqing District, Tianjin 300384, China; Jinan Municipal Engineering Design and Research Institute (Group) Co., Ltd., Xuzhou Branch, Xuzhou, Jiangsu 221000, China.
Ecotoxicol Environ Saf. 2025 Jan 1;289:117446. doi: 10.1016/j.ecoenv.2024.117446. Epub 2024 Dec 2.
Pharmaceutical wastewater treatment plants (PWWTPs) serve as reservoirs for antibiotic-resistant bacteria (ARBs) and antibiotic resistance genes (ARGs). In this study, a multiantibiotic-resistant strain of Acinetobacter lwoffii (named N4) was isolated from the dewatered sludge of a PWWTP. N4 exhibited high resistance to both antibiotics and metals, with minimum inhibitory concentrations (MICs) of chloramphenicol and cefazolin reaching 1024 mg·L and MICs of Cu and Zn reaching 512 mg·L. Co-sensitization experiments revealed that when antibiotics are co-existing with heavy metal ions (such as TET and Cd, AMP and Cu) could enhance the resistance of N4 to them. Whole-genome sequencing of N4 revealed a genome size of 0.37 Mb encoding 3359 genes. Among these, 23 ARGs were identified, including dfrA26, bl2be, catB3, qnrB, rosB, tlrC, smeD, smeE, mexE, ceoB, oprN, acrB, adeF, ykkC, ksgA and sul2, which confer resistance through mechanisms such as efflux pumps, enzyme modification and target bypass. Additionally, the N4 genome contained 187 genes associated with human disease and 249 virulence factors, underscoring its potential pathogenicity. Overall, this study provides valuable insights into ARBs in PWWTPs and highlights the potential risks posed by multidrug-resistant strains such as N4.
制药废水处理厂（PWWTPs）是抗生素抗性细菌（ARBs）和抗生素抗性基因（ARGs）的储存库。在本研究中，从一家制药废水处理厂的脱水污泥中分离出一株多重耐药的鲁氏不动杆菌（命名为N4）。N4对抗生素和金属均表现出高抗性，氯霉素和头孢唑林的最低抑菌浓度（MICs）达到1024 mg·L，铜和锌的MICs达到512 mg·L。共敏化实验表明，当抗生素与重金属离子共存时（如四环素和镉、氨苄青霉素和铜），可增强N4对它们的抗性。N4的全基因组测序显示基因组大小为0.37 Mb，编码3359个基因。其中，鉴定出23个ARGs，包括dfrA26、bl2be、catB3、qnrB、rosB、tlrC、smeD、smeE、mexE、ceoB、oprN、acrB、adeF、ykkC、ksgA和sul2，它们通过外排泵、酶修饰和靶点旁路等机制赋予抗性。此外，N4基因组包含187个与人类疾病相关的基因和249个毒力因子，突出了其潜在致病性。总体而言，本研究为制药废水处理厂中的ARBs提供了有价值的见解，并突出了N4等多重耐药菌株带来的潜在风险。
