Linezolid against penicillin-sensitive and -resistant pneumococci in the rabbit meningitis model

Linezolid, a new oxazolidinone antibiotic, showed good penetration (38 +/- 4%) into the meninges of rabbits with levels in the CSF ranging from 9.5 to 1.8 mg/L after two iv injections (20 mg/kg). Linezolid was clearly less ef fective than ceftriaxone against a penicillin-sensitive pneumococcal strain . Against a penicillin-resistant strain, linezolid had slightly inferior ki lting rates compared with the standard regimen (ceftriaxone combined with v ancomycin). In vitro, linezolid was marginally bactericidal at concentratio ns above the MIC (5 x and 10 x MIG).