Brain injury in experimental neonatal meningitis due to group B streptococci

J Neuropathol Exp Neurol. 1995 Jul;54(4):531-9. doi: 10.1097/00005072-199507000-00007.


We have characterized the pattern of brain injury in a rat model of meningitis caused by group B streptococci (GBS). Infant rats (12-14 days old; n = 69) were infected intracisternally with 10 microliters of GBS (log10(2.3) to 4.5 colony-forming units). Twenty hours later, illness was assessed clinically and cerebrospinal fluid was cultured. Animals were either immediately euthanized for brain histopathology or treated with antibiotics and examined later. Early GBS meningitis was characterized clinically by severe obtundation and seizures, and histopathologically by acute inflammation in the subarachnoid space and ventricles, a vasculopathy characterized by vascular engorgement, and neuronal injury that was most prominent in the cortex and often followed a vascular pattern. Incidence of seizures, vasculopathy and neuronal injury correlated with the inoculum size (p < 0.01). Early injury was almost completely prevented by treatment with dexamethasone. Within days after meningitis, injured areas became well demarcated and showed new cellular infiltrates. Thirty days post-infection, brain weights of infected animals treated with antibiotics were decreased compared to uninfected controls (1.39 +/- 0.18 vs 1.64 +/- 0.1 g; p < 0.05). Thus, GBS meningitis in this model caused extensive cortical neuronal injury resembling severe neonatal meningitis in humans.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Animals, Newborn
  • Brain Damage, Chronic / etiology*
  • Brain Damage, Chronic / pathology
  • Brain Damage, Chronic / prevention & control
  • Ceftriaxone / therapeutic use
  • Cerebral Cortex / blood supply
  • Cerebral Cortex / pathology*
  • Cerebral Ventricles / pathology
  • Consciousness Disorders / etiology
  • Dexamethasone / therapeutic use*
  • Granulocytes / pathology
  • Meningitis, Bacterial / cerebrospinal fluid
  • Meningitis, Bacterial / complications
  • Meningitis, Bacterial / drug therapy
  • Meningitis, Bacterial / pathology*
  • Neurons / pathology
  • Organ Size
  • Rats
  • Rats, Sprague-Dawley
  • Seizures / etiology
  • Severity of Illness Index
  • Streptococcal Infections / cerebrospinal fluid
  • Streptococcal Infections / complications
  • Streptococcal Infections / drug therapy
  • Streptococcal Infections / pathology*
  • Streptococcus agalactiae*
  • Subarachnoid Space / pathology
  • Vasculitis / pathology


  • Ceftriaxone
  • Dexamethasone