Effect of linezolid compared with glycopeptides in methicillin-resistant Staphylococcus aureus severe pneumonia in piglets

Chest. 2009 Jun;135(6):1564-1571. doi: 10.1378/chest.08-2169. Epub 2009 Jan 13.


Objectives: To investigate if compared with glycopeptides, antimicrobial therapy (AMT) with linezolid (LZD) improves the outcome in methicillin-resistant Staphylococcus aureus (MRSA) experimental pneumonia in mechanically ventilated piglets.

Methods: The MRSA minimal inhibitory concentration (MIC) was 0.5 for vancomycin (VAN), 0.25 for teicoplanin (TEI), and 2.0 microg/mL for LZD was inoculated in Largewhite-Landrace piglets divided into five groups. One group (n = 6) did not receive mechanical ventilation (MV) or AMT. Those in the remaining groups received MV and VAN (n = 9), TEI (n = 7), LZD (n = 9), or no AMT (n = 7). Plasma and BAL tumor necrosis factor-alpha, interleukin-6, and C-reactive protein (CRP) concentrations, postmortem lung pathology, cultures (lung, blood, and BAL) and plasma, epithelial lining fluid (ELF), and lung antibiotic concentrations were evaluated.

Measurements and main results: All piglets developed severe pneumonia; lung pathology score was lower in those receiving LZD vs those receiving glycopeptides (p = 0.049) or no AMT (p = 0.037). Serum CRP and serum and BAL cytokines increased; there were no differences between the groups. Fourteen died spontaneously at 44.4 +/- 16.8 h; the remaining 24 were killed after 72 to 96 h. The concentrations of the antimicrobial agents tested in 15 piglets were higher than the MIC for the three antimicrobial agents in peak and trough plasma, ELF, and lung specimens. Survival at 72 h was higher in the LZD comparing with the no-AMT group.

Conclusions: Inoculation produced severe MRSA pneumonia. LZD AMT was associated with lower pathology score, better survival, and a trend to better clearance of MRSA, not attributable exclusively to pharmacokinetic or pharmacodynamic reasons.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetamides / pharmacology*
  • Analysis of Variance
  • Animals
  • Biopsy, Needle
  • Disease Models, Animal
  • Dose-Response Relationship, Drug
  • Drug Administration Schedule
  • Glycopeptides / pharmacology*
  • Immunohistochemistry
  • Linezolid
  • Methicillin-Resistant Staphylococcus aureus / drug effects*
  • Oxazolidinones / pharmacology*
  • Pneumonia, Staphylococcal / drug therapy*
  • Pneumonia, Staphylococcal / mortality
  • Pneumonia, Staphylococcal / pathology
  • Probability
  • Random Allocation
  • Respiration, Artificial
  • Sensitivity and Specificity
  • Severity of Illness Index
  • Survival Rate
  • Swine
  • Treatment Outcome


  • Acetamides
  • Glycopeptides
  • Oxazolidinones
  • Linezolid