Antimicrobial Resistance and Microbial Ecology Group, School of Medicine, National University of Ireland, Galway; Centre for One Health, Ryan Institute, National University of Ireland, Galway.
Antimicrobial Resistance and Microbial Ecology Group, School of Medicine, National University of Ireland, Galway; Centre for One Health, Ryan Institute, National University of Ireland, Galway.
Environ Int. 2021 Jul;152:106466. doi: 10.1016/j.envint.2021.106466. Epub 2021 Mar 8.
Water bodies worldwide have proven to be vast reservoirs of clinically significant antibiotic resistant organisms. Contamination of waters by anthropogenic discharges is a significant contributor to the widespread dissemination of antibiotic resistance. The aim of this research was to investigate multiple different anthropogenic sources on a national scale for the role they play in the environmental propagation of antibiotic resistance. A total of 39 water and 25 sewage samples were collected across four local authority areas in the West, East and South of Ireland. In total, 211 Enterobacterales were isolated (139 water, 72 sewage) and characterised. A subset of isolates (n=60) were chosen for whole genome sequencing. Direct comparisons of the water versus sewage isolate collections revealed a higher percentage of sewage isolates displayed resistance to cefoxitin (46%) and ertapenem (32%), while a higher percentage of water isolates displayed resistance to tetracycline (55%) and ciprofloxacin (71%). Half of all isolates displayed extended spectrum beta-lactamase (ESBL) production phenotypically (n = 105/211; 50%), with bla detected in 99/105 isolates by PCR. Carbapenemase genes were identified in 11 isolates (6 sewage, 5 water). The most common variant was bla (n=6), followed by bla (n=2) and bla (n=2). Whole genome sequencing analysis revealed numerous different sequence types in circulation in both waters and sewage including E. coli ST131 (n=15), ST38 (n=8), ST10 (n=4) along with Klebsiella ST405 (n=3) and ST11 (n=2). Core genome MLST (cgMLST) comparisons uncovered three highly similar Klebsiella isolates originating from hospital sewage and two nearby waters. The Klebsiella isolates from an estuary and seawater displayed 99.1% and 98.8% cgMLST identity to the hospital sewage isolate respectively. In addition, three pairs of E. coli isolates from different waters also revealed cgMLST similarities, indicating widespread dissemination and persistence of certain strains in the aquatic environment. These findings highlight the need for routine monitoring of water bodies used for recreational and drinking purposes for the presence of multi-drug resistant organisms.
全世界的水体已被证明是具有临床重要意义的抗生素耐药菌的巨大储库。人为排放物对水体的污染是抗生素耐药性广泛传播的一个重要因素。本研究的目的是调查全国范围内多个不同的人为污染源在环境中传播抗生素耐药性方面的作用。在爱尔兰西部、东部和南部的四个地方当局地区共采集了 39 个水样和 25 个污水样。共分离出 211 株肠杆菌科（139 个水样，72 个污水样）并进行了鉴定。选择了一组（n=60）分离株进行全基因组测序。水样与污水分离株的直接比较显示，污水分离株对头孢西丁（46%）和厄他培南（32%）的耐药率更高，而水样分离株对四环素（55%）和环丙沙星（71%）的耐药率更高。所有分离株中有一半（n=105/211；50%）表现出扩展谱β-内酰胺酶（ESBL）的产生表型，PCR 检测到 99 个分离株中有 bla 基因。11 个分离株中鉴定出碳青霉烯酶基因（n=6 个污水，n=5 个水）。最常见的变体是 bla（n=6），其次是 bla（n=2）和 bla（n=2）。全基因组测序分析显示，在水和污水中循环的多种不同序列类型，包括大肠杆菌 ST131（n=15）、ST38（n=8）、ST10（n=4），以及克雷伯菌 ST405（n=3）和 ST11（n=2）。核心基因组 MLST（cgMLST）比较揭示了来自医院污水和两个附近水域的三个高度相似的克雷伯菌分离株。来自河口和海水的克雷伯菌分离株与医院污水分离株的 cgMLST 同源性分别为 99.1%和 98.8%。此外，来自不同水域的三个大肠杆菌分离株对也显示出 cgMLST 相似性，表明某些菌株在水生环境中的广泛传播和持续存在。这些发现强调了需要对用于娱乐和饮用水的水体进行常规监测，以检测多药耐药菌的存在。
