Polymyxin resistance in Klebsiella pneumoniae

Polymyxin resistance (PR) is an emerging threat. We sequenced K. pneumoniae isolates from a single healthcare system from 2011 - 2018. We noted multiplicity of genomic alterations leading to PR in clinical Klebsiella pneumoniae, both within individual patients and isolate clusters. Polymyxin exposure rather than transmission played a key role in spread of PR.