To describe an outbreak due to an extensively drug-resistant Klebsiella pneumonia harbouring blaNDM-1 and/or blaOXA-48 in Barcelona (2015-2017)

The objective of this study is to describe an outbreak due to an extensively drug-resistant Klebsiella pneumoniae. Patients were prospectively identified based on results from the active surveillance program and/or clinical samples. All epidemic isolates were identified (MALDI-TOF), tested for antimicrobial susceptibility (MicroScan?), screened by PCR (GeneXpert?) and genotyped through PFGE (XbaI). Three selected isolates were further studied by Whole Genome Sequencing (Illumina MiSeq). The index case was a carrier of a Klebsiella pneumoniae isolate which belonged to ST147, harboured blaNDM-1 plus blaCTX-M-15 beta-lactamases and was only susceptible to colistin. As the outbreak advanced the primogenital isolate acquired an additional OXA-48 carbapenemase and a second event led to the NDM-1 loss. Despite all applied measures, the detection of sporadic cases remains active.