Jill A. Rebuck *, Keith M Olsen *, Paul D. Fey **, Kimberly L. Bergman, Mark E. Rupp **
* Jill A. Rebuck, Keith M Olsen – Department of Pharmacy Practice
** Paul D. Fey, Kimberly L. Bergman, Mark E. Rupp – Department of Internal Medicine, University of Nebraska Medical Center, 986045 Nebraska Medical Center, Omaha, USA
Abstract
The in vitro activities were determined and time-kill studies of cefepime, imipenem-cilastatin, meropenem and piperacillin-tazobactamwere performed against SHV- and TEM-derived extended-spectrum β-lactamases (ESBL s). Sequence-confirmed SHV-5, TEM-10 and TEM-26 β-lactamases were transferred into Escherichls coli C600N by conjugation. lmipenem and meropenem were more active (MIC range 0.0625-0.25 mg/L) than cefepime (MIC range 2-8 mg/L) and piperacillin-tazobactam (MIC range 8-2 mg/L). Regrowth of strains expressing TEM-10 and TEM-26 was noted at all cefepime and piperacillin tazobactam concentrations studied. lmipenem-cilastatin and meropenem demonstrated rapid, sustained bactericidal activity uninfluenced by the type of ESBL expres sed.