Mutant prevention concentrations, <i>in vitro</i> resistance evolution dynamics, and mechanisms of resistance to imipenem and imipenem/relebactam in carbapenem-susceptible <i>Klebsiella pneumoniae</i> isolates showing ceftazidime/avibactam resistance.

ABSTRACT: Klebsiella pneumoniae carbapenemase (KPC) variants selected during ceftazidime/avibactam treatment usually develop susceptibility to carbapenems and carbapenem/β-lactamase inhibitors, such as imipenem and imipenem/relebactam. We analyzed imipenem and imipenem/relebactam single-step mutant frequencies, resistance development trajectories and differentially selected resistance mechanisms using two representative K. pneumoniae isolates that had developed ceftazidime/avibactam resistance during therapy (ST512/KPC-31 and ST258/KPC-35). Mutant frequencies and mutant prevention concentrations were measured in Mueller-Hinton agar plates containing incremental concentrations of imipenem or imipenem/relebactam. Resistance dynamics were determined after incubation for 7 days in 10 mL MH

SUBMITTER: Blanco-Martin T 

PROVIDER: S-EPMC11619344 | biostudies-literature | 2024 Dec

REPOSITORIES: biostudies-literature