Kerschner Heidrun, Jernej Linda, Cabal Adriana, Hyden Patrick, Machherndl-Spandl Sigrid, Berning Lucia, Blaimschein Anna, Ruppitsch Werner, Apfalter Petra, Hartl Rainer
National Reference Center for Antimicrobial Resistance, Institute for Hygiene, Microbiology and Tropical Medicine, Ordensklinikum Linz Elisabethinen, Fadingerstraße 1, 4020, Linz, Austria.
Medical Faculty, Johannes Kepler University Linz, Altenberger Strasse 69, 4040, Linz, Austria.
Antimicrob Resist Infect Control. 2025 Apr 7;14(1):27. doi: 10.1186/s13756-025-01539-0.
In May 2018, an outbreak of NDM-5-carrying Escherichia coli (NDM-5-EC) was detected at the hemato-oncology department of a tertiary care center in Austria. This report details the outbreak investigation, control measures and the whole genome sequencing (WGS) data of the outbreak isolates.
A total of 15 isolates (seven clinical isolates from allogenic stem cell transplant (SCT) recipients and eight wastewater isolates recovered from patients' toilets) were analyzed by whole genome sequencing.
Genome based typing identified two clusters of the high risk clones ST167/CT12607 and ST617/CT2791. Long-read sequencing of selected isolates from both clusters identified two different plasmids, however with a highly similar genetic context of the bla containing region. Genomic analysis revealed the presence of additional resistance genes, including bla, and bla, and virulence factors. Four patients were colonized with NDM-5-EC, two patients suffered bacteremia caused by the outbreak strain and two deaths were associated with an NDM-5-EC infection. The outbreak source was traced to toilet sewage pipes, which remained persistently contaminated despite extensive cleaning and disinfection. Successful eradication of NDM-5-EC from the installations required disassembly, hot water pressure washing of the sewage pipes and complete replacement of all movable parts. Additionally, colonized patients were instructed to use wheeled commodes instead of toilets, and a pre-admission screening strategy was implemented for all patients undergoing hematologic stem cell transplantation. The outbreak was successfully terminated in November 2020.
NDM-5-EC, especially high-risk clones such as ST167 and ST617, can persist in hospital wastewater systems despite cleaning and disinfection efforts and can cause prolonged outbreaks. Therefore, a comprehensive bundle of interventions like the ones applied in our study is essential, especially in clinical settings with heavily immunosuppressed patients.
2018年5月，奥地利一家三级护理中心的血液肿瘤科检测到携带NDM-5的大肠杆菌（NDM-5-EC）暴发。本报告详细介绍了此次暴发的调查、控制措施以及暴发菌株的全基因组测序（WGS）数据。
对总共15株分离株（7株来自异基因干细胞移植（SCT）受者的临床分离株和8株从患者厕所回收的废水分离株）进行全基因组测序分析。
基于基因组的分型确定了两个高风险克隆群，即ST167/CT12607和ST617/CT2791。对两个群中选定分离株的长读长测序确定了两种不同的质粒，但bla基因所在区域的遗传背景高度相似。基因组分析揭示了其他耐药基因的存在，包括bla和bla，以及毒力因子。4名患者被NDM-5-EC定植，2名患者因暴发菌株导致菌血症，2例死亡与NDM-5-EC感染有关。暴发源头追溯到厕所污水管道，尽管进行了广泛的清洁和消毒，但仍持续受到污染。要成功根除设施中的NDM-5-EC，需要拆卸、用热水高压冲洗污水管道并完全更换所有可移动部件。此外，指示定植患者使用带轮坐便器而不是马桶，并对所有接受血液干细胞移植的患者实施入院前筛查策略。此次暴发于2020年11月成功终止。
NDM-5-EC，尤其是ST167和ST617等高风险克隆，尽管进行了清洁和消毒工作，但仍可在医院废水系统中持续存在，并可导致长时间的暴发。因此，像我们研究中应用的那样全面的一系列干预措施至关重要，特别是在有大量免疫抑制患者的临床环境中。
