mSphere. 2020 Aug 26;5(4):e00775-20. doi: 10.1128/mSphere.00775-20.
Ceftazidime-avibactam is a potent antibiotic combination against Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae Here, we describe a unique ceftazidime-avibactam-resistant and carbapenem-susceptible K. pneumoniae strain harboring a novel bla KPC-14 variant. This strain was isolated from a New York City patient in 2003, which predates the introduction of avibactam. Despite resistance to ceftazidime-avibactam, the strain was susceptible to imipenem-relebactam and meropenem-vaborbactam. Comprehensive genomic sequencing revealed that bla KPC-14 is harbored on an ST6 IncN plasmid associated with the early spread of bla KPC IMPORTANCE KPC is currently the most common carbapenemase identified in the United States. More than 40 KPC variants have been described, of which KPC-2 and KPC-3 are the most frequent clinical variants. However, our understanding of the genetic structures and β-lactam resistance profiles of other novel KPC variants remains incomplete. Here, we report a novel bla KPC variant (bla KPC-14) and the complete genome sequence of bla KPC-14-harboring K. pneumoniae strain BK13048, which is susceptible to carbapenems but resistant to ceftazidime-avibactam. To the best of our knowledge, this is one of the earliest KPC-producing K. pneumoniae strains exhibiting resistance to ceftazidime-avibactam.