Emergence of CP-K. Pneumoniae ST5994 in Cantabria, Spain

This study aims to describe the emergence of the Carbapenemase Producing - Klebsiella pneumoniae (CP-KP) ST5994/OXA-48 clone in Cantabria region (Spain). To our current knowledge, only three CP-KP ST5994 had been previously found, all of them outside our borders. For this study, we sequenced 32 CP-KP ST5994 strains and 33 parental CP-KP ST307 strains. This new clone carries two conjugative plasmids carrying OXA-48 carbapenemase and CTX-M-15 extended-spectrum beta-lactamase (ESBL).Since its first appearance in our tertiary hospital in the second quarter of 2023, the newly emerged ST5994 rapidly became the dominant CP-KP strain within the reference hospital and then in the region over the last two years, displacing the dominant HRC in previous years, such as ST11 and ST307. The origin of the samples and WGS analysis suggests multiple events of indirect chains of transmissions within and outside of the hospital, rather than a confined outbreak.