In vitro activities of parenteral beta-lactam antimicrobials against TEM-10-, TEM-26- and SHV-5-derived extended-spectrum beta-lactamases expressed in an isogenic Escherichia coli host.
The in vitro activities were determined and time-kill studies of cefepime, imipenem-cilastatin, meropenem and piperacillin-tazobactam were performed against SHVand TEM-derived extended-spectrum beta-lactamases (ESBLs). Sequence-confirmed SHV-5, TEM-10 and TEM-26 beta-lactamases were transferred into Escherichia coli C600N by conjugation. Imipenem 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 8-32 mg/L). Regrowth of strains expressing TEM-10 and TEM-26 was noted at all cefepime and piperacillin-tazobactam concentrations studied. Imipenem-cilastatin and meropenem demonstrated rapid, sustained bactericidal activity uninfluenced by the type of ESBL expressed.
Rebuck
J A
JA
Department of Pharmacy Practice and Department of Internal Medicine, University of Nebraska Medical Center, 986045 Nebraska Medical Center, Omaha, NE 68198-6045, USA.
Olsen
K M
KM
Fey
P D
PD
Bergman
K L
KL
Rupp
M E
ME
D003227:Conjugation, Genetic; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D008826:Microbial Sensitivity Tests / Q000379:methods; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*; D047090:beta-Lactams / Q000494:pharmacology*
D047090:beta-Lactams; C117193:beta-lactamase SHV-5; C087312:beta-lactamase TEM-26; D001618:beta-Lactamases; C034413:beta-lactamase TEM-1