Metallo-β-lactamase-producing Pseudomonas aeruginosa in the Netherlands: the nationwide emergence of a single sequence type.

Recently, the first outbreak of clonally related VIM-2 metallo-β-lactamase (MBL)-producing Pseudomonas aeruginosa in a Dutch tertiary-care centre was described. Subsequently, a nationwide surveillance study was performed in 2010-2011, which identified the presence of VIM-2 MBL-producing P. aeruginosa in 11 different hospitals. Genotyping by multiple-locus variable-number tandem-repeat analysis (MLVA) showed that the majority of the 82 MBL-producing isolates found belonged to a single MLVA type (n = 70, 85%), identified as ST111 by multilocus sequence typing (MLST). As MBL-producing isolates cause serious infections that are difficult to treat, the presence of clonally related isolates in various hospitals throughout the Netherlands is of nationwide concern.