Larsen Astri Lervik, Pedersen Torunn, Sundsfjord Arnfinn, Ross Theodor A, Guleng Anja Dyresen, Haug Jon Birger, Pöntinen Anna K, Samuelsen Ørjan
Department of Infection Control, Østfold Hospital Trust, Sarpsborg, Norway.
Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway.
Infect Prev Pract. 2024 Dec 21;7(1):100430. doi: 10.1016/j.infpip.2024.100430. eCollection 2025 Mar.
Nosocomial outbreaks with multidrug-resistant bacteria with a probable reservoir in hospital toilets and drainage systems have been increasingly reported.
To investigate an increase in bacteraemia with extended-spectrum β-lactamase (ESBL)-producing at our hospital in 2021; the epidemiology of the outbreak suggested an environmental source.
Available clinical isolates from patient with infection or rectal carriage from 2019 to 2022 were collected. Clinical information was gathered from included patients and sampled sinks, shower drains, and toilet water. Short- and long-read whole-genome sequencing (WGS) was performed on patient and environmental isolates to assess phylogenetic relationships, antibiotic resistance genes/mutations, and plasmid profiles.
WGS revealed four clusters and a polyclonal population consisting of ESBL-producing and . All clusters contained both clinical and environmental isolates. The environmental sampling revealed widespread contamination of the outbreak strains in the outbreak ward, and plasmid analyses indicated possible transfer of plasmids between species and clones. Most environmental findings in the outbreak ward were from toilet water, and enhanced cleaning of bathrooms and toilets was introduced. The following year, a decrease in outbreak strains in systemic infections was observed.
This investigation uncovered a polyclonal outbreak of multidrug-resistant and and unveiled a persistent reservoir of outbreak clones in the drainage system and toilet water, facilitating exchange of resistance genes. The risk of toilet water as a source of clinical infections warrants further investigation.
医院内由多重耐药菌引起的医院感染暴发越来越多地被报道，这些细菌可能在医院厕所和排水系统中存在储存宿主。
调查我院2021年产超广谱β-内酰胺酶（ESBL）细菌引起的菌血症增加情况；此次暴发的流行病学调查提示存在环境来源。
收集2019年至2022年感染患者或直肠携带患者的可用临床分离株。从纳入的患者以及采样的水槽、淋浴排水口和厕所水中收集临床信息。对患者和环境分离株进行短读长和长读长全基因组测序（WGS），以评估系统发育关系、抗生素耐药基因/突变和质粒图谱。
WGS显示有四个聚类以及一个由产ESBL的[细菌名称1]和[细菌名称2]组成的多克隆群体。所有聚类均包含临床和环境分离株。环境采样显示暴发病房中暴发菌株广泛污染，质粒分析表明质粒可能在不同菌种和克隆之间转移。暴发病房的大多数环境检测结果来自厕所水，因此加强了对浴室和厕所的清洁。次年，观察到全身感染中暴发菌株数量减少。
本调查发现了多重耐药的[细菌名称1]和[细菌名称2]的多克隆暴发，并揭示了排水系统和厕所水中存在持续的暴发克隆储存宿主，促进了耐药基因的交换。厕所水作为临床感染源的风险值得进一步调查。
