DIFFERENCES OF PATHOPHYSIOLOGY IN EXPERIMENTAL MENINGITIS CAUSED BY 3 STRAINS OF STREPTOCOCCUS-PNEUMONIAE

Differences in cytochemical and pathophysiologic abnormalities in experimental meningitis caused by pneumococcal strains A, B, and C were determined. Strain C produced the most severe abnormalities of cerebrospinal fluid (CSF) concentrations of lactate (P < .01), protein (P < .02), and glucose (P < .01), CSF white blood cell count (P < .04), cerebral blood flow (P < .02), and clinical signs (P < .05). Brain edema occurred only with strains A and C, with no association with disease severity; intracranial hypertension was also independent of disease severity. Strain B, not C, achieved the highest bacterial titers in the CSF (P < .005). The widely different abilities of strains of Streptococcus pneumoniae to induce intracranial abnormalities suggest that virulence determinants affect not only evasion of defense during colonization and invasion, as shown in other models, but also determine the course of disease once infection has been established. Differences of cell-wall metabolism among pneumococcal strains may play a role in this latter phase of the development of meningitis.