Hospital water environment and antibiotic use: key factors in a nosocomial outbreak of carbapenemase-producing Serratia marcescens.

The healthcare water environment is a potential reservoir of carbapenem-resistant organisms (CROs). To report the role of the water environment as a reservoir and the infection control measures applied to suppress a prolonged outbreak of Klebsiella pneumoniae carbapenemase-producing Serratia marcescens (KPC-SM) in two intensive care units (ICUs). The outbreak occurred in the ICUs of a tertiary hospital from October 2020 to July 2021. Comprehensive patient contact tracing and environmental assessments were conducted, and a case-control study was performed to identify factors associated with the acquisition of KPC-SM. Associations among isolates were assessed via pulsed-field gel electrophoresis (PFGE). Antibiotic usage was analysed. The outbreak consisted of two waves involving a total of 30 patients with KPC-SM. Multiple environmental cultures identified KPC-SM in a sink, a dirty utility room, and a communal bathroom shared by the ICUs, together with the waste bucket of a continuous renal replacement therapy (CRRT) system. The genetic similarity of the KPC-SM isolates from patients and the environment was confirmed by PFGE. A retrospective review of 30 cases identified that the use of CRRT and antibiotics was associated with acquisition of KPC-SM (P < 0.05). There was a continuous increase in the use of carbapenems; notably, the use of colistin has increased since 2019. Our study demonstrates that CRRT systems, along with other hospital water environments, are significant potential sources of resistant micro-organisms, underscoring the necessity of enhancing infection control practices in these areas.

Kim UJ ，Choi SM ，Kim MJ ，Kim S ，Shin SU ，Oh SR ，Park JW ，Shin HY ，Kim YJ ，Lee UH ，Choi OJ ，Park HY ，Shin JH ，Kim SE ，Kang SJ ，Jung SI ，Park KH ... -  《-》

Emergence of Serratia marcescens, Klebsiella pneumoniae, and Escherichia coli Isolates possessing the plasmid-mediated carbapenem-hydrolyzing beta-lactamase KPC-2 in intensive care units of a Chinese hospital.

Cai JC ，Zhou HW ，Zhang R ，Chen GX ... -  《-》

The ICU environment contributes to the endemicity of the "Serratia marcescens complex" in the hospital setting.

Aracil-Gisbert S ，Fernández-De-Bobadilla MD ，Guerra-Pinto N ，Serrano-Calleja S ，Pérez-Cobas AE ，Soriano C ，de Pablo R ，Lanza VF ，Pérez-Viso B ，Reuters S ，Hasman H ，Cantón R ，Baquero F ，Coque TM ... -  《mBio》

Outbreak of multidrug-resistant Serratia marcescens infection in a neonatal intensive care unit.

Maragakis LL ，Winkler A ，Tucker MG ，Cosgrove SE ，Ross T ，Lawson E ，Carroll KC ，Perl TM ... -  《-》

In vivo acquisition and risk of inter-species spread of bla (KPC-3)-plasmid from Klebsiella pneumoniae to Serratia marcescens in the lower respiratory tract.

Bielli A ，Piazza A ，Cento V ，Comandatore F ，Lepera V ，Gatti M ，Brioschi P ，Vismara C ，Bandi C ，Perno CF ... -  《-》