Mataseje Laura F, Lerminiaux Nicole, Lagacé-Wiens Philippe, Walkty Andrew, Adam Heather J, Poutanen Susan, Baxter Melanie, Karlowsky James A, McCracken Melissa, Golding George R, Zhanel George G
National Microbiology Laboratory, Public Health Agency of Canada, 1015 Arlington Street, Winnipeg, Manitoba R3E 3M4, Canada.
Department of Medical Microbiology and Infectious Diseases, Max Rady College of Medicine, University of Manitoba, Room 543-745 Bannatyne Avenue, Winnipeg Manitoba R3E 0J9, Canada.
J Antimicrob Chemother. 2025 Aug 28;80(Supplement_2):ii54-ii61. doi: 10.1093/jac/dkaf221.
To review phenotypic and genotypic characteristics of ertapenem-resistant Enterobacterales isolates identified by the CANWARD study from 2007 to 2023.
Bacterial isolates were collected as part of the CANWARD surveillance study from 2007 to 2023. CLSI M7 broth microdilution antimicrobial susceptibility testing (12th edition, 2024) was performed. MICs were interpreted by CLSI M100 breakpoints (34th edition, 2024). WGS was performed to identify antimicrobial resistance markers.
Only 134 (0.7%) of the 19 642 Enterobacterales were ertapenem-resistant. Carbapenemase producing Enterobacterales (CPE) accounted for 17.9% (n = 24) of ertapenem-resistant isolates and were predominantly Klebsiella pneumoniae (54.2%) and Escherichia coli (20.8%). KPC was the most common carbapenemase identified (62.5%). K. pneumoniae ST834, ST16 and ST258, and E. coli ST131 were the most frequent STs detected. CPE percent resistant values ranged from 20.8% to 25.0% for ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam. Most non-CPE ertapenem-resistant isolates were Enterobacter spp. (51.8%), E. coli (15.5%) and K. pneumoniae (10.9%). Non-CPE STs were most commonly E. cloacae ST108, ST50 and ST133, and E. coli ST131. Non-CPE percent resistant values ranged from 2.7% to 4.5% for ceftazidime/avibactam, imipenem/relebactam and meropenem/vaborbactam. At least one of an AmpC, an ESBL or porin alternations were observed in most non-CPE isolates.
In Canada, ertapenem-resistant Enterobacterales remain uncommon (0.7%). CPE isolates demonstrated higher percent resistant values for multiple antimicrobial classes and harboured more antimicrobial resistance genes than non-CPE isolates. Continued monitoring for ertapenem-resistant Enterobacterales, particularly CPE, is important given their associated multidrug resistance to both established and newer agents.
回顾2007年至2023年通过加拿大抗菌药物耐药性监测（CANWARD）研究鉴定的耐厄他培南肠杆菌分离株的表型和基因型特征。
作为CANWARD监测研究的一部分，收集了2007年至2023年的细菌分离株。采用美国临床和实验室标准协会（CLSI）M7肉汤微量稀释法进行抗菌药物敏感性试验（第12版，2024年）。最低抑菌浓度（MIC）根据CLSI M100折点（第34版，2024年）进行解释。进行全基因组测序（WGS）以鉴定抗菌药物耐药性标志物。
在19642株肠杆菌中，只有134株（0.7%）耐厄他培南。产碳青霉烯酶肠杆菌（CPE）占耐厄他培南分离株的17.9%（n = 24），主要是肺炎克雷伯菌（54.2%）和大肠埃希菌（20.8%）。KPC是最常见的碳青霉烯酶（62.5%）。肺炎克雷伯菌ST834、ST16和ST258以及大肠埃希菌ST131是检测到的最常见序列类型（ST）。CPE对头孢他啶/阿维巴坦、亚胺培南/瑞来巴坦和美罗培南/伏巴拉坦的耐药百分比值在20.8%至25.0%之间。大多数非CPE耐厄他培南分离株是肠杆菌属（51.8%）、大肠埃希菌（15.5%）和肺炎克雷伯菌（10.9%）。非CPE的ST最常见的是阴沟肠杆菌ST108、ST50和ST133以及大肠埃希菌ST131。非CPE对头孢他啶/阿维巴坦、亚胺培南/瑞来巴坦和美罗培南/伏巴拉坦的耐药百分比值在2.7%至4.5%之间。在大多数非CPE分离株中观察到至少一种AmpC、超广谱β-内酰胺酶（ESBL）或孔蛋白改变。
在加拿大，耐厄他培南肠杆菌仍然不常见（0.7%）。与非CPE分离株相比，CPE分离株对多种抗菌药物类别的耐药百分比值更高，并且携带更多的抗菌药物耐药基因。鉴于耐厄他培南肠杆菌，特别是CPE对已有的和新型药物都具有多重耐药性，持续监测耐厄他培南肠杆菌非常重要。
