KPC-12 with a L169M substitution in the Ω loop has reduced carbapenemase activity

Eur J Clin Microbiol Infect Dis. 2021 Feb 17. doi: 10.1007/s10096-021-04198-2. Online ahead of print.


KPC-12 is a variant of KPC-2 with a L169M substitution in the Ω loop, but its resistance spectrum was not reported. blaKPC-12 was cloned, and KPC-12 exhibited significantly decreased activities against imipenem, meropenem, aztreonam, and piperacillin-tazobactam with ≥4-fold lower MICs than KPC-2. However, unlike the L169P substitution in KPC-35, activities against ceftazidime and ceftazidime-avibactam of KPC-12 were unaltered. This highlights that different substitutions at the same position of carbapenemases may have varied impact on the activity.

PMID:33595757 | DOI:10.1007/s10096-021-04198-2