Handwashing Sink Contamination and Carbapenem-resistant Klebsiella Infection in the Intensive Care Unit: A Prospective Multicenter Study.

BACKGROUND

Handwashing sinks can become contaminated by carbapenem-resistant Klebsiella (CRK), including carbapenem-resistant Klebsiella pneumoniae (CRKP) and carbapenem-resistant Klebsiella oxytoca (CRKO), but whether they are major sources of CRK infections remains unknown.

METHODS

We performed a prospective multicenter study in 16 intensive care units (ICUs) (9 general and 7 neonatal) at 11 hospitals. All sinks at these locations were sampled to screen CRK. All CRK clinical isolates recovered between 2 weeks before and 3 months after sampling in ICUs with CRK-positive sinks or other participating ICUs at the same hospital were collected. Whole-genome sequencing of all isolates was performed. Isolates of the same sequence type (ST) were assigned to clones by calling single-nucleotide polymorphisms.

RESULTS

Among 158 sinks sampled, 6 CRKP and 6 CRKO were recovered from 12 sinks in 7 ICUs, corresponding to a 7.6% CRK contamination rate. Twenty-eight clinical isolates were collected, and all were CRKP. The 34 CRKP isolates belonged to 7 STs, including ST789 (n = 14, all had blaNDM-5); ST11 (n = 12, 5 belonged to KL64 and 7 to KL47, all had blaKPC-2); ST709 (n = 4, all had blaNDM-5); and ST16, ST20, ST1027, and ST2407 (n = 1 each). One particular ST789 clone caused an outbreak and contaminated a sink. ST11_KL47 sink isolates were likely the source of a cluster of clinical isolates. Two ST11_KL64 isolates belonged to a common clone but were from 2 hospitals.

CONCLUSIONS

Contaminated sinks were not the major source of CRK in our local settings. ST789 blaNDM-5-carrying CRKP might represent an emerging lineage causing neonatal infections.