Penetration of the blood-brain barrier by Staphylococcus aureus: contribution of membrane-anchored lipoteichoic acid

J Mol Med (Berl). 2010 Jun;88(6):633-9. doi: 10.1007/s00109-010-0630-5. Epub 2010 Apr 24.

Abstract

Staphylococcus aureus is one of the most prevalent organisms responsible for nosocomial infections, and cases of community-acquired S. aureus infection have continued to increase despite widespread preventative measures. Pathologies attributed to S. aureus infection are diverse; ranging from dermal lesions to bacteremia, abscesses, and endocarditis. Reported cases of S. aureus-associated meningitis and brain abscesses have also increased in recent years, however, the precise mechanism whereby S. aureus leave the bloodstream and gain access to the central nervous system (CNS) are not known. Here we demonstrate for the first time that S. aureus efficiently adheres to and invades human brain microvascular endothelial cells (hBMEC), the single-cell layer which constitutes the blood-brain barrier (BBB). The addition of cytochalasin D, an actin microfilament aggregation inhibitor, strongly reduced bacterial invasion, suggesting an active hBMEC process is required for efficient staphylococcal uptake. Furthermore, mice injected with S. aureus exhibited significant levels of brain bacterial counts and histopathologic evidence of meningeal inflammation and brain abscess formation, indicating that S. aureus was able to breech the BBB in an experimental model of hematogenous meningitis. We found that a YpfP-deficient mutant, defective in lipoteichoic acid (LTA) membrane anchoring, exhibited a decreased ability to invade hBMEC and correlated to a reduced risk for the development of meningitis in vivo. Our results demonstrate that LTA-mediated penetration of the BBB may be a primary step in the pathogenesis of staphylococcal CNS disease.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Blood-Brain Barrier / metabolism*
  • Blood-Brain Barrier / microbiology*
  • Cell Line
  • Cell Membrane / chemistry*
  • Cell Wall / metabolism
  • Endothelial Cells / cytology
  • Endothelial Cells / microbiology
  • Humans
  • Lipopolysaccharides / metabolism*
  • Male
  • Mice
  • Staphylococcal Infections / metabolism
  • Staphylococcal Infections / microbiology
  • Staphylococcus aureus / cytology
  • Staphylococcus aureus / genetics
  • Staphylococcus aureus / metabolism
  • Staphylococcus aureus / pathogenicity*
  • Teichoic Acids / metabolism*

Substances

  • Bacterial Proteins
  • Lipopolysaccharides
  • Teichoic Acids
  • lipoteichoic acid