Effect of Porins and Plasmid-Mediated AmpC β-Lactamases on the Efficacy of β-Lactams in Rat Pneumonia Caused by Klebsiella pneumoniae

Abstract

The in vivo activities of imipenem, meropenem, and cefepime were studied in a model of rat pneumonia caused by a plasmid-mediated AmpC β-lactamase ACT-1-producing Klebsiella pneumoniae strain ( K. pneumoniae strain 12) and a derivative porin-deficient mutant ( K. pneumoniae strain 12dp). No differences between these activities were seen with K. pneumoniae 12. Only meropenem showed an activity slightly better than that of imipenem with K. pneumoniae 12dp.