Vancomycin versus teicoplanin in the therapy of experimental methicillin-resistant Staphylococcus aureus (MRSA) meningitis

Daptomycin versus Vancomycin in Treatment of Methicillin-Resistant Staphylococcus aureus Meningitis in an Experimental Rabbit Model

“…S. aureus ATCC 43300 (vancomycin MIC, 1 mg/liter; daptomycin MIC, 0.064 mg/liter [measured in duplicate using the Etest; AB Biodisk, Solna, Sweden]) was used as the infecting bacterial strain (2).…”

“…New Zealand White rabbits weighing 2.5 to 3.0 kg were anesthetized by intramuscular injections of ketamine (35 mg/kg of body weight) and xylazine (5 mg/kg) before each intraventricular intervention, including induction of meningitis and cerebrospinal fluid (CSF) sampling (2). The duration of anesthesia was 10 to 15 min.…”

“…CSF and serum drug levels were measured by a bioassay technique in samples obtained at 8 hours after drug treatment (2,4). At the end of the study period (8 h after the initiation of drug treatment), animals were humanely killed by intravenous infusion of a high dose of nembutal.…”

“…Bacterial concentrations in the CSF were measured at 16 h after infection (at the end of the incubation period and before the first dose of vancomycin or daptomycin was administered) and 8 h after initiation of drug treatment by plating undiluted and serial 10-fold and 100-fold dilutions of CSF (20-l volume) (5) on 5% sheep blood agar and incubated at 37°C for 24 h. The bacterial response was evaluated for three categories: full response, sterilization of CSF; partial response, any decrease in bacterial count; bacteriological failure, an increased bacterial count (2).…”

“…The first-line treatment for MRSA meningitis is vancomycin (7,8). Although vancomycin does not penetrate at all to the CSF without inflammation of the meninges, it penetrates to the CSF in a limited amount during meningitis (2,7,8). There may be treatment failure in strains with MICs that are Ͼ1 mg/dl, which theoretically may also be associated with a 20-mg/kg vancomycin dosage every 12 h (9).…”