Nosocomial transmission of NDM-1-containing Klebsiella pneumoniae ST147 in a Dutch pediatric oncology center associated with patients from Ukraine

We studied nosocomial transmission of multidrug-resistant bla NDM-1-containing Klebsiella pneumoniae ST147 in a Dutch pediatric oncology center. Whole-genome multilocus sequence typing revealed two genetic clusters consisting of 2 and 5 K. pneumoniae isolates, both from Ukrainian medical evacuees and Dutch patients. Ukrainian patients were colonized at admission, and two Dutch patients developed bacteremia. Temporal and spatial transmission links were assessed and sampling of sinks revealed environmental contamination of bla NDM-1-containing K. pneumoniae with genetic relatedness to cluster isolates. Phylogenetic analysis of 163 K. pneumoniae ST147 isolates from the Dutch national surveillance revealed that transmission-related isolates formed a unique phylogenetic branch.In conclusion, we demonstrate nosocomial transmission of unique bla NDM-1-containing K. pneumoniae ST147 strains introduced by Ukrainian patients. Sink drains colonized by genetically similar bla NDM-1-containing strains in rooms designated as spatial links within the cluster were considered the potential source of transmission. Healthcare professionals should be aware of these risks, particularly in settings with susceptible patients exposed to antibiotic pressure.