title: Efficacies of piperacillin-tazobactam and cefepime in rats with experimental intra-abdominal abscesses due to an extended-spectrum beta-lactamase-producing strain of Klebsiella pneumoniae.
abstract: The in vivo activities of piperacillin-tazobactam and cefepime were compared with those of ticarcillin-clavulanate, ceftazidime, cefotaxime, and imipenem in a rat model of intra-abdominal abscess with a strain of Klebsiella pneumoniae elaborating an extended-spectrum beta-lactamase (TEM-26). With the exception of ceftazidime, all of the antimicrobial agents significantly reduced bacterial counts within abscesses at the end of therapy compared with those in untreated controls. Residual viable cell counts (mean +/- standard deviation in log10 CFU/gram) were as follows: control, 8.76 +/- 0.97; ceftazidime, 8.00 +/- 0.76; piperacillin-tazobactam, 3.87 +/- 1.72; ticarcillin-clavulanate, 3.74 +/- 1.34; cefepime, 3.15 +/- 1.19; cefotaxime, 2.61 +/- 0.77; imipenem, 2.41 +/- 0.93. Imipenem was more effective than either of the inhibitor combinations (P < 0.05). Cefotaxime was unexpectedly effective given its poor in vivo activity against this organism in our earlier studies, which used a different dose and total duration of therapy (L. B. Rice, J. D. C. Yao, K. Klimm, G. M. Eliopoulos, and R. C. Moellering, Jr., Antimicrob. Agents Chemother. 35:1243-1244, 1991). These observations suggest that the effectiveness of cephalosporins in the treatment of experimental infections caused by extended-spectrum beta-lactamase-producing K. pneumoniae may be highly dependent on dosing regimens, even for a specific organism and site of infection.
authors.affiliation: Department of Medicine, Deaconess Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA.
authors.forename: C
authors.initials: C
authors.lastname: Thauvin-Eliopoulos
authors.forename: M F
authors.initials: MF
authors.lastname: Tripodi
authors.forename: R C
authors.initials: RC
authors.lastname: Moellering
authors.forename: G M
authors.initials: GM
authors.lastname: Eliopoulos
mesh_terms: D018784:Abdominal Abscess / Q000188:drug therapy* / Q000382:microbiology*; D000818:Animals; D000077723:Cefepime; D002511:Cephalosporins / Q000627:therapeutic use*; D004359:Drug Therapy, Combination / Q000627:therapeutic use*; D004791:Enzyme Inhibitors / Q000627:therapeutic use*; D007710:Klebsiella Infections / Q000188:drug therapy*; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000201:enzymology; D008297:Male; D008826:Microbial Sensitivity Tests; D010397:Penicillanic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use; D010878:Piperacillin / Q000008:administration & dosage / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D000078142:Tazobactam; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D002511:Cephalosporins; D004791:Enzyme Inhibitors; D000077723:Cefepime; D010397:Penicillanic Acid; D001618:beta-Lactamases; D000078142:Tazobactam; D010878:Piperacillin