Broad-Spectrum β-Lactam Antibiotics for Treating Experimental Peritonitis in Mice Due to Klebsiella pneumoniae Producing the Carbapenemase OXA-48

A lethal peritonitis model was induced in mice with a Klebsiella pneumoniae isolate producing the carbapenemase OXA-48. Administration of a single dose (up to 100 mg/kg) of the antibiotic piperacillin-tazobactam, imipenem-cilastatin, ertapenem, or cefotaxime had little or no impact on lethality. Ceftazidime had the highest efficacy in vivo, which mirrored its in vitro activity; this was not the case for carbapenems. Therefore, ceftazidime may be recommended for the treatment of infections due to OXA-48 producers if they do not coproduce an extended-spectrum beta-lactamase or a plasmid-mediated AmpC cephalosporinase.