Emergence and rapid global dissemination of CTX-M-15-associated Klebsiella pneumoniae strain ST307.

OBJECTIVES: Recent reports indicate the emergence of a new carbapenemase-producing Klebsiella pneumoniae clone, ST307. We sought to better understand the global epidemiology and evolution of this clone and evaluate its association with antimicrobial resistance (AMR) genes. METHODS: We collated information from the literature and public databases and performed a comparative analysis of 95 ST307 genomes (including 37 that were newly sequenced). RESULTS: We show that ST307 emerged in the mid-1990s (nearly 20 years prior to its first report), is already globally distributed and is intimately associated with a conserved plasmid harbouring the blaCTX-M-15 ESBL gene and several other AMR determinants. CONCLUSIONS: Our findings support the need for enhanced surveillance of this widespread ESBL clone in which carbapenem resistance has occasionally emerged.