Comparative therapeutic efficacy of clinafloxacin in a pneumococcal meningitis mouse model.

The therapeutic efficacy of clinafloxacin, a fluoroquinolone in clinical trials, was compared with that of ciprofloxacin and ceftriaxone in a novel pneumococcal meningitis mouse model. Mice were challenged by the intracerebral ventricular route with 50 IL of a lethal bacterial suspension and treated subcutaneously 2 h later. Both penicillin-susceptible and multidrug-resistant pneumococcal strains were used for evaluation. Survival percentages were calculated as the median curative dose (CD50) using log-probit statistical methods. Ceftriaxone was the most active agent against the penicillin-susceptible strain (CD50 = 2 mg/kg), but showed a 30-fold decrease in potency against the resistant strain. Clinafloxacin was equally effective against both strains, and proved to be the most active agent against the penicillin-resistant pneumococcus.