cefmenoxime and Meningitis--Pneumococcal

Cefmenoxime, a new semisynthetic cephalosporin, was evaluated in vitro and in vivo in comparison with penicillin G against a type III group B streptococcal strain. In vitro, the minimal inhibitory and minimal bactericidal concentrations of the two drugs were very close (less than or equal to 2 dilutions). In-vivo studies using experimental bacteraemia and meningitis in newborn rats revealed that despite similar drug levels, cefmenoxime had significantly greater bactericidal titres in blood at 6-7 h after administration and bacterial clearance from blood was significantly faster with cefmenoxime than with penicillin G at the end of one day of treatment. In addition, all animals with cefmenoxime therapy had bactericidal titres in cerebrospinal fluid greater than or equal to 1:8 at 1-2 h after administration, whereas most (67%) animals receiving penicillin G had titres less than 1:8. However, overall efficacy of cefmenoxime was similar to that of penicillin G. These findings suggest that cefmenoxime may be an effective alternative against group B streptococcal infection.

Topics: Animals; Cefmenoxime; Cefotaxime; Meningitis, Pneumococcal; Microbial Sensitivity Tests; Penicillin G; Rats; Sepsis; Streptococcal Infections; Streptococcus agalactiae

In order to define the characteristics of the antibacterial activity of beta-lactam antibiotics in the treatment of bacterial meningitis, the relationship between cerebrospinal fluid (CSF) drug concentrations and the rate of bacterial killing was investigated for penicillin G and four new cephalosporins in an animal model of meningitis due to Streptococcus pneumoniae. All five drugs showed a significant correlation between increasing drug concentrations in CSF and increasing bactericidal rates. Minimal activity was observed in CSF at drug concentrations of approximately the broth minimal bactericidal concentration (MBC). Maximal activity occurred with CSF concentrations 10-30 times higher. In vitro tests did not reproduce the unique correlation of increasing drug concentrations and killing activity found in vivo. When evaluating new beta-lactam antibiotics for the treatment of bacterial meningitis, it is reasonable to establish a minimum standard of CSF drug concentrations of greater than or equal to 30 times the MBC against the infecting organism.

Topics: Animals; Anti-Bacterial Agents; Cefmenoxime; Cefotaxime; Ceftriaxone; Meningitis, Pneumococcal; Moxalactam; Penicillin G; Rabbits; Streptococcus pneumoniae