Carbapenemase-producing Enterobacterales (CPE) bacteria are a critical global health concern; New Delhi metallo-β-lactamase (NDM) enzymes account for >25% of all CPE found in Switzerland. We characterized NDM-positive CPE submitted to the Swiss National Reference Center for Emerging Antibiotic Resistance during a 2-year period (January 2019–December 2020) phenotypically and by using whole-genome sequencing. Most isolates were either Klebsiella pneumoniae (59/141) or Escherichia coli (52/141), and >50% were obtained from screening swabs. Among the 108 sequenced isolates, NDM-1 was the most prevalent variant, occurring in 56 isolates, mostly K. pneumoniae (34/56); the next most prevalent was NDM-5, which occurred in 49 isolates, mostly E. coli (40/49). Fourteen isolates coproduced a second carbapenemase, predominantly an OXA-48-like enzyme, and almost one third of isolates produced a 16S rRNA methylase conferring panresistance to aminoglycosides. We identified successful plasmids and global lineages as major factors contributing to the increasing prevalence of NDMs in Switzerland.

产生碳青霉烯酶的肠杆菌(CPE) 细菌是一个重要的全球健康问题；新德里金属-β-内酰胺酶 (NDM) 酶占瑞士发现的所有 CPE 的 25% 以上。我们在 2 年期间（2019 年 1 月至 2020 年 12 月）期间通过表型和全基因组测序对提交给瑞士国家新兴抗生素耐药性参考中心的 NDM 阳性 CPE 进行了表征。大多数分离株是肺炎克雷伯菌(59/141) 或大肠杆菌(52/141)，并且 >50% 来自筛查拭子。在 108 个已测序的分离株中，NDM-1 是最普遍的变异体，出现在 56 个分离株中，主要是肺炎克雷伯菌（34/56）；其次最流行的是 NDM-5，它出现在 49 个分离株中，主要是大肠杆菌(40/49)。十四个分离株共同产生了第二种碳青霉烯酶，主要是一种 OXA-48 样酶，几乎三分之一的分离株产生了一种 16S rRNA 甲基化酶，赋予氨基糖苷类全耐药性。我们确定成功的质粒和全球谱系是导致瑞士 NDM 日益流行的主要因素。