Smyth Cian, Leigh Robert J, Do Thi Thuy, Walsh Fiona
Antimicrobial Resistance & Microbiome Research Group, Department of Biology, The Kathleen Lonsdale Institute for Human Health Research, Maynooth University, Maynooth, Co, Kildare, Ireland.
School of Medicine, TILDA,, Trinity College (University of Dublin), Pearse Street, Dublin, D02R924, Ireland.
NPJ Antimicrob Resist. 2025 Sep 9;3(1):78. doi: 10.1038/s44259-025-00151-x.
Plasmids facilitate antimicrobial resistance (AMR) gene spread via horizontal gene transfer, yet the mobility of genes in wastewater treatment plant (WWTP) resistomes remains unclear. We sequenced 173 circularised plasmids transferred from WWTP effluent into Escherichia coli and characterised their genetic content. Multiple multidrug-resistant plasmids were identified, with a significant number of mega-plasmids (>100 kb). Almost all plasmids detected existed with other plasmids i.e. as communities rather than lone entities. These plasmid communities enabled non-AMR plasmids to survive antimicrobial selection by co-existing with resistant partners. Our data demonstrates the highly variable nature of plasmids in addition to their capacity to carry mobile elements and genes within these highly variable regions. The impact of these variations on plasmid ecology, persistence, and transfer requires further investigation. Plasmid communities warrant exploration across biomes, as many non-resistant plasmids escape elimination by co-existing with AMR plasmids in the same bacterial host, representing a previously unrecognised survival strategy.
质粒通过水平基因转移促进抗菌药物耐药性（AMR）基因的传播，但废水处理厂（WWTP）耐药基因组中基因的流动性仍不清楚。我们对从污水处理厂流出物转移到大肠杆菌中的173个环化质粒进行了测序，并对其遗传内容进行了表征。鉴定出多个多重耐药质粒，其中有大量的巨型质粒（>100 kb）。几乎所有检测到的质粒都与其他质粒共存，即以群落形式存在而非单独存在。这些质粒群落使非AMR质粒能够通过与耐药伙伴共存而在抗菌选择中存活下来。我们的数据表明，质粒除了在这些高度可变区域携带移动元件和基因的能力外，还具有高度可变的性质。这些变异对质粒生态、持久性和转移的影响需要进一步研究。由于许多非耐药质粒通过与同一细菌宿主中的AMR质粒共存而逃避消除，代表了一种以前未被认识的生存策略，因此质粒群落在各个生物群落中都值得探索。
