Tumeo Anna, McDonagh Francesca, Kovarova Aneta, Ryan Kate, Clarke Christina, Miliotis Georgios
Antimicrobial Resistance and Microbial Ecology Group, School of Medicine, University of Galway, Galway, Ireland.
Department of Medical Microbiology, Health Services Executive, Galway University Hospital, Galway, Ireland.
J Glob Antimicrob Resist. 2025 Jan;40:62-65. doi: 10.1016/j.jgar.2024.11.018. Epub 2024 Dec 5.
While Escherichia coli phylogroup-A is typically associated with commensal strains, some isolates can harbour virulence and exhibit multidrug-resistant (MDR) phenotypes. We report the draft genome of a rare instance of carbapenem, fosfomycin and colistin resistant E. coli phylogroup-A, isolated as part of routine screening of a human patient in a clinical setting in Ireland.
E. coli E230738 was identified using MALDI-ToF/MS. Antibiotic susceptibility testing was performed using the Sensititre-EUMDRXXF plate. Whole-genome-sequencing was conducted with NextSeq1000, and genomic analysis identified antibiotic-resistance-genes (ARGs) and virulence-factors (VFs). Phylogenetic analysis was performed using whole-genome-multilocus-sequence-typing (wgMLST).
E. coli E230738 genome was identified to belong to phylogroup-A/ST10 complex and to harbour 63 ARGs, 17 of which acquired. Resistance to beta-lactams, including carbapenems and cephalosporins was likely due to chromosomally identified bla. Colistin resistance appeared associated with acquired mcr-1.1. Despite lacking fosfomycin-inactivating-enzymes, fosfomycin resistance was observed, possibly due to efflux pumps. Forty-seven chromosomal VFs were identified, involved in adhesion and iron acquisition amongst other properties. Plasmid replicons associated with the spread of MDR genes such as IncHI2/HI2A were detected. wgMLST analysis showed the closest relative being a strain from the UK, exhibiting differences in the sequences of 851 genes.
This is a first detected instance of a bla and mcr-1.1 co-occurring in E. coli in Ireland. The MDR profile of E. coli E230738 highlights the growing public health concern posed by the dissemination of MDR E. coli lineages with limited treatment options and underscores the need for clinical screening coupled with genomic surveillance to better understand evolving MDR patterns in E. coli.
虽然大肠杆菌A系统发育群通常与共生菌株相关，但一些分离株可能携带毒力并表现出多重耐药（MDR）表型。我们报告了一株罕见的对碳青霉烯类、磷霉素和黏菌素耐药的大肠杆菌A系统发育群的基因组草图，该菌株是在爱尔兰临床环境中对一名人类患者进行常规筛查时分离得到的。
使用基质辅助激光解吸电离飞行时间质谱（MALDI-ToF/MS）鉴定大肠杆菌E230738。使用Sensititre-EUMDRXXF平板进行药敏试验。用NextSeq1000进行全基因组测序，基因组分析确定抗生素抗性基因（ARG）和毒力因子（VF）。使用全基因组多位点序列分型（wgMLST）进行系统发育分析。
大肠杆菌E230738基因组被鉴定属于A系统发育群/ST10复合体，含有63个ARG，其中17个是获得性的。对β-内酰胺类抗生素（包括碳青霉烯类和头孢菌素类）的耐药性可能是由于染色体上鉴定出的bla。黏菌素耐药性似乎与获得性mcr-1.1有关。尽管缺乏磷霉素失活酶，但仍观察到磷霉素耐药性，可能是由于外排泵。鉴定出47个染色体VF，参与黏附、铁摄取等特性。检测到与MDR基因传播相关的质粒复制子，如IncHI2/HI2A。wgMLST分析显示其最接近的亲缘菌株来自英国，在851个基因的序列上存在差异。
这是爱尔兰首次检测到bla和mcr-1.1在大肠杆菌中共存的实例。大肠杆菌E230738的MDR谱突出了具有有限治疗选择的MDR大肠杆菌谱系传播对公共卫生造成日益严重关注的问题，并强调了临床筛查与基因组监测相结合以更好地了解大肠杆菌中不断演变的MDR模式的必要性。
