Efficacy of linezolid against Panton-Valentine leukocidin (PVL)-positive meticillin-resistant Staphylococcus aureus (MRSA) in a mouse model of haematogenous pulmonary infection

Int J Antimicrob Agents. 2009 Nov;34(5):477-81. doi: 10.1016/j.ijantimicag.2009.06.024. Epub 2009 Aug 7.


Many strains of community-acquired meticillin-resistant Staphylococcus aureus (MRSA) have a pore-forming leukotoxin, known as Panton-Valentine leukocidin (PVL), which can cause severe necrotising pneumonia. Linezolid (LZD) is a new antibacterial agent with potent antibacterial activity against MRSA. In this study, a mouse model of haematogenous pulmonary infection was used to compare the efficacies of LZD and vancomycin (VAN) against pulmonary infection caused by PVL-positive S. aureus. Following antibiotic administration for 3 days, the number of viable bacteria (mean+/-standard error of the mean) in the control, VAN and LZD groups was 6.77+/-0.14, 5.29+/-0.27 and 4.25+/-0.33 log colony-forming units/lung, respectively. LZD significantly decreased the number of viable bacteria in the lungs compared with the control and VAN groups (P<0.05). The survival rate at Day 7 post-inoculation was higher in the LZD group (100%) than in the VAN group (50%) or the control group (0%). Histopathological examination and cytokine analysis also showed the beneficial efficacy of LZD compared with VAN. In conclusion, LZD significantly reduced bacterial numbers and inflammation in a mouse model of PVL-positive S. aureus haematogenous infection and improved the survival rate of infected mice compared with VAN. LZD is clinically effective against PVL-positive S. aureus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetamides / therapeutic use*
  • Animals
  • Anti-Bacterial Agents / therapeutic use*
  • Bacteremia / complications*
  • Bacterial Toxins / biosynthesis*
  • Colony Count, Microbial
  • Cytokines / analysis
  • Exotoxins / biosynthesis*
  • Histocytochemistry
  • Leukocidins / biosynthesis*
  • Linezolid
  • Lung / chemistry
  • Lung / microbiology
  • Lung / pathology
  • Male
  • Methicillin-Resistant Staphylococcus aureus / drug effects*
  • Methicillin-Resistant Staphylococcus aureus / isolation & purification
  • Mice
  • Oxazolidinones / therapeutic use*
  • Pneumonia, Staphylococcal / drug therapy*
  • Pneumonia, Staphylococcal / microbiology
  • Survival Analysis
  • Treatment Outcome
  • Virulence Factors / biosynthesis*


  • Acetamides
  • Anti-Bacterial Agents
  • Bacterial Toxins
  • Cytokines
  • Exotoxins
  • Leukocidins
  • Oxazolidinones
  • Panton-Valentine leukocidin
  • Virulence Factors
  • Linezolid