2022年春季,上奥地利州的一家医院检测到产生金属β-内酰胺酶的铜绿假单胞菌(MBL-Pa)感染增加。为了查明感染源并停止进一步的传播,我们进行了流行病学暴发调查,包括基于全基因组测序(WGS)的分型.最终病例定义包括在2020年至2023年期间入院的病例,其中MBL-Pa位于确定的三个基因组簇之一中。此外,从2017年开始,调查范围扩大到包括历史案例。进行核心基因组多位点序列分型以评估分离株之间的遗传相关性。从医院环境中获得54个临床铜绿假单胞菌分离株和8个铜绿假单胞菌分离株。除9个分离株之外,所有分离株都分为三个基因组簇之一(ST235/blaVIM-1,ST111/blaVIM-2或ST621/blaIMP-13),被认为是独特的,长期爆发,涉及52例病例中的47例。第1组(ST111/blaVIM-2)和第2组(ST235/blaVIM-1)最可能的感染源是重症监护病房(ICU)洗手间的水槽。簇3克隆(ST621/blaIMP-13)可能起源于2020年的泌尿科病房,然后在几年后传播到ICU。然而,这个克隆的医院来源无法证实。2023年3月,在实施控制措施(礼服,患者隔离,筛选,和每日消毒),没有进一步检测到MLB-Pa,疫情被认为已经结束。由于ICU在铜绿假单胞菌的传播中起着重要作用,重点应该放在基因组监测上,预防感染,在这样的病房里控制。
目的:我们工作的意义在于成功解决了上奥地利州一家医院中三起长期爆发的MBL-Pa感染。通过全面的流行病学调查以及基于WGS的铜绿假单胞菌分离株分型,该研究确定了三个不同的基因组簇,导致涉及47例病例的长期暴发。调查指出,ICU洗手间的水槽可能是其中两个集群的感染源。这项研究证明了手卫生等控制措施的有效性,Gowning,患者隔离,筛选,和消毒,以阻止进一步传播并结束疫情。这强调了基因组监测和控制措施的关键作用,特别是在像ICU这样的高风险环境中,减少MBL-Pa感染的医院传播。
In spring 2022, an increase in metallo-β-lactamase-producing Pseudomonas aeruginosa (MBL-Pa) infections was detected in a hospital in Upper Austria. To identify the source of infection and to stop further transmissions, an epidemiological outbreak investigation including whole-genome sequencing (WGS)-based typing was conducted. The final case definition included cases admitted to the hospital between 2020 and 2023 with an MBL-Pa in one of the three genomic clusters identified. In addition, the investigation was extended to include historical cases from 2017. Core genome multilocus sequence typing was performed to assess the genetic relatedness between the isolates. Fifty-four clinical P. aeruginosa isolates and eight P. aeruginosa isolates from the hospital environment were obtained. All but nine isolates grouped into one of three genomic clusters (ST235/blaVIM-1, ST111/blaVIM-2, or ST621/blaIMP-13), which were considered to be distinct, prolonged outbreaks involving 47 out of 52 cases. The most likely source of infection for cluster 1 (ST111/blaVIM-2) and cluster 2 (ST235/blaVIM-1) was sinks in the intensive care unit (ICU) washroom. Cluster 3 clone (ST621/blaIMP-13) could have originated in the urology ward in 2020 and then spread to the ICU years later. However, the nosocomial origin of this clone could not be proven. In March 2023, following the implementation of control measures (gowning, patient isolation, screening, and daily disinfection), no further MLB-Pa was detected, and the outbreaks were considered to be over. As ICUs play an important role in the transmission of P. aeruginosa, emphasis should be placed on genomic surveillance, infection prevention, and control in such wards.
OBJECTIVE: The significance of our work lies in the successful resolution of three prolonged outbreaks of MBL-Pa infections in a hospital in Upper Austria. Through a comprehensive epidemiological investigation coupled with WGS-based typing of P. aeruginosa isolates, the study identified three distinct genomic clusters responsible for prolonged outbreaks involving 47 cases. The investigation pinpointed sinks in the ICU washroom as the likely source of infection for two of the clusters. The study demonstrates the effectiveness of control measures such as hand hygiene, gowning, patient isolation, screening, and disinfection in stopping further transmission and bringing the outbreaks to a close. This underscores the critical role of genomic surveillance and control measures, particularly in high-risk settings like ICUs, in reducing nosocomial transmission of MBL-Pa infections.