title: Piperacillin with and without tazobactam against extended-spectrum beta-lactamase-producing Pseudomonas aeruginosa in a rat thigh abscess model.
abstract: BACKGROUND
  We compared the antibacterial effect of piperacillin, piperacillin-tazobactam and imipenem in a paired rat thigh abscess model.
  
  
  METHODS
  Two abscesses were provoked in the thighs of rats, one on the right with an extended-spectrum beta-lactamase (OXA-14)-producing Pseudomonas aeruginosa (Ps-162) and the other on the left thigh with a control strain.
  
  
  RESULTS
  The colony counts from the abscesses in log 10 colony-forming units per gram (mean +/- SD) in the imipenem group were 2.78 +/- 1.71 and 3.19 +/- 1.66, in the piperacillin-tazobactam group 4.36 +/- 0.23 and 2.44 +/- 1.97, and in the piperacillin group 4.44 +/- 0.21 and 3.71 +/- 0.99 for Ps-162 and the control strain, respectively. The mean colony counts were significantly different (p < 0.05) between Ps-162 and the control strain in the piperacillin and piperacillin-tazobactam groups.
  
  
  CONCLUSIONS
  These data showed that piperacillin and piperacillin-tazobactam were significantly less effective against extended-spectrum beta-lactamase-producing P. aeruginosa, while imipenem was equally effective against both Ps-162 and the control strain in this abscess model.
authors.affiliation: Mikrobiyoloji AD, Kocaeli Universitesi Tip Fakultesi, Kocaeli, Türkiye.
authors.forename: A
authors.initials: A
authors.lastname: Karadenizli
authors.forename: B
authors.initials: B
authors.lastname: Mutlu
authors.forename: E
authors.initials: E
authors.lastname: Okay
authors.forename: F
authors.initials: F
authors.lastname: Kolayli
authors.forename: H
authors.initials: H
authors.lastname: Vahaboglu
mesh_terms: D000038:Abscess / Q000188:drug therapy* / Q000382:microbiology; D000818:Animals; D004359:Drug Therapy, Combination / Q000627:therapeutic use*; D015378:Imipenem / Q000627:therapeutic use; D008297:Male; D023421:Models, Animal; D010397:Penicillanic Acid / Q000031:analogs & derivatives* / Q000627:therapeutic use; D010878:Piperacillin / Q000627:therapeutic use; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000201:enzymology; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000201:enzymology; D051381:Rats; D017208:Rats, Wistar; D018709:Statistics, Nonparametric; D000078142:Tazobactam; D013848:Thigh; D001618:beta-Lactamases / Q000378:metabolism*
chemical_list: D015378:Imipenem; D010397:Penicillanic Acid; C096781:beta-lactamase OXA-14; D001618:beta-Lactamases; D000078142:Tazobactam; D010878:Piperacillin