Per- and polyfluoroalkyl substances (PFAS) as emerging pollutants are ubiquitous and disrupt biological processes across water boundaries. Their coexistence with antibiotic resistance genes (ARGs) in water matrix is associated with the spread of ARGs via conjugative transfer, posing a threat to public health. However, their role in natural transformation—where microorganisms actively take up extracellular ARGs (eARGs)—and the subsequent persistence and expression of ARGs after transformation remains poorly understood. Here, we demonstrated that environmentally relevant concentrations (0.1-10 µg/L) of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), two typical PFAS, increased transformation frequencies by 2.54- and 3.26-fold, respectively. This increase was driven by increased cell envelope permeability, biofilm formation, reactive oxygen species (ROS) production, and upregulation of DNA uptake genes. At higher concentrations (100 µg/L), PFAS inhibited transformation. Nevertheless, PFOA and PFOS at all tested concentrations promoted long-term plasmid in vivo stability, reducing plasmid loss rates from 68.5% to 6% and 38.7%, respectively. Furthermore, they induced ARGs expression in transformants by up to 1.33- and 1.37-fold. Our findings revealed that PFOA and PFOS impacted the spread, persistence, and expression of ARGs, from extracellular uptake to intracellular activity in bacteria. These results highlight the underestimated environmental health risks posed by PFAS and underscore the intricate chemical and biological co-contamination in aquatic ecosystems and wastewater treatment.

中文翻译：

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全氟烷基和多氟烷基物质通过增强自然转化、体内稳定性和细菌表达，加剧了质粒携带的抗生素抗性基因的普遍性


全氟烷基和多氟烷基物质 （PFAS） 作为新兴污染物无处不在，会破坏跨越水边界的生物过程。它们与水基质中的抗生素耐药基因 （ARG） 共存与 ARGs 通过共轭转移传播有关，对公共卫生构成威胁。然而，它们在自然转化中的作用——微生物积极吸收细胞外 ARG （eARG）——以及转化后 ARG 的后续持久性和表达仍然知之甚少。在这里，我们证明，两种典型的 PFAS 全氟辛酸 （PFOA） 和全氟辛烷磺酸 （PFOS） 的环境相关浓度 （0.1-10 μg/L） 将转化频率分别提高了 2.54 倍和 3.26 倍。这种增加是由细胞包膜通透性增加、生物膜形成、活性氧 （ROS） 产生和 DNA 摄取基因的上调推动的。在较高浓度 （100 μg/L） 下，PFAS 抑制了转化。尽管如此，所有测试浓度的 PFOA 和 PFOS 都促进了质粒的长期体内稳定性，将质粒损失率分别从 68.5% 降低到 6% 和 38.7%。此外，它们在转化体中诱导 ARGs 表达高达 1.33 倍和 1.37 倍。我们的研究结果表明，PFOA 和 PFOS 影响 ARGs 的传播、持久性和表达，从细胞外摄取到细菌的细胞内活动。这些结果突出了 PFAS 带来的环境健康风险被低估，并强调了水生生态系统和废水处理中错综复杂的化学和生物共同污染。