Yao Zhuocheng, Yang Yuhan, Gong Yanchun, Shi Shiyi, Ge Yunying, Zeng Weiliang, Zhao Deyi, Cao Jianming, Zhou Tieli, Shen Mo
Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China.
School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, China.
Front Microbiol. 2025 Jul 7;16:1595833. doi: 10.3389/fmicb.2025.1595833. eCollection 2025.
Disinfectants are commonly utilized by humans to combat microorganisms. However, residual disinfectants may promote environmental antimicrobial resistance by facilitating horizontal gene transfer (HGT) of antibiotic resistance genes. Bronopol is a routinely used disinfectant that persists in the environment, and previous studies have concentrated on its ecotoxicity rather than its implications on the propagation of resistance genes. This study aimed to establish an conjugation model to investigate whether bronopol promotes the transfer of antibiotic resistance genes (ARGs) via plasmid conjugation. Using DH5α and DC8855 as donors harboring RP4-7 and -positive plasmids, respectively, and J53 as the recipient strain, we found that sub-inhibitory concentrations of bronopol (2 μg/L and 20 μg/L) significantly increased the conjugative transfer frequency (CTF) of both plasmids. Mechanistic analysis revealed that bronopol enhanced bacterial membrane permeability, as demonstrated by propidium iodide (PI) staining, 1-N-phenylnaphthylamine (NPN) fluorescent probes, transmission electron microscopy (TEM), and upregulation of the outer membrane protein gene . Additionally, bronopol treatment upregulated RP4 plasmid-encoded genes involved in DNA transfer/replication () and the global regulator of HGT (/). These findings highlight a previously unrecognized role of bronopol in facilitating the dissemination of antibiotic resistance genes, particularly those of clinical significance.
消毒剂被人类广泛用于对抗微生物。然而，残留消毒剂可能通过促进抗生素抗性基因的水平基因转移（HGT）来增强环境中的抗菌抗性。溴硝醇是一种在环境中持续存在的常用消毒剂，以往的研究集中在其生态毒性而非其对抗性基因传播的影响。本研究旨在建立一个接合模型，以研究溴硝醇是否通过质粒接合促进抗生素抗性基因（ARGs）的转移。分别使用携带RP4-7和阳性质粒的DH5α和DC8855作为供体，J53作为受体菌株，我们发现亚抑制浓度的溴硝醇（2μg/L和20μg/L）显著提高了两种质粒的接合转移频率（CTF）。机制分析表明，溴硝醇增强了细菌膜通透性，碘化丙啶（PI）染色、1-N-苯基萘胺（NPN）荧光探针、透射电子显微镜（TEM）以及外膜蛋白基因的上调均证明了这一点。此外，溴硝醇处理上调了参与DNA转移/复制（）和HGT全局调节因子（/）的RP4质粒编码基因。这些发现突出了溴硝醇在促进抗生素抗性基因传播，特别是具有临床意义的抗性基因传播方面以前未被认识的作用。
