Antimicrobial agents and chemotherapy
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Antimicrob. Agents Chemother. · Sep 1985
Comparative StudyEfficacy of cefmenoxime in experimental Escherichia coli bacteremia and meningitis.
Cefmenoxime, a new semisynthetic cephalosporin structurally similar to cefotaxime, was evaluated for its activities in vitro and in vivo against a K1 Escherichia coli strain in comparison with activities of cefotaxime and ampicillin. In vitro the MICs and MBCs of both cefmenoxime and cefotaxime were the same, 1/16th and 1/32nd those of ampicillin, respectively. ⋯ The mortality was significantly greater in rats with bacterial counts before therapy of greater than or equal to 10(6) CFU/ml of blood than in animals with lower counts. Overall, the in vivo efficacy of cefmenoxime was similar to that of cefotaxime; thus it could be useful in the therapy of neonatal E. coli infection.
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Antimicrob. Agents Chemother. · Sep 1985
Comparative StudyComparison of cefotaxime, imipenem-cilastatin, ampicillin-gentamicin, and ampicillin-chloramphenicol in the treatment of experimental Escherichia coli bacteremia and meningitis.
In a search for more effective antimicrobial therapy of neonatal Escherichia coli infection, newer beta-lactam antibiotics, cefotaxime and imipenem, were evaluated for their activities against a K1 E. coli strain in vitro and in vivo, and the results were compared with those of conventional therapeutic regimens for neonatal E. coli infection: ampicillin-gentamicin and ampicillin-chloramphenicol. Measured by MICs and MBCs, cefotaxime and imipenem were 8- to 512-fold more active in vitro than the older agents. For in vivo studies, the following daily doses were used: 50 mg/kg for each of imipenem and cilastatin; 100 mg/kg for each of cefotaxime, ampicillin, and chloramphenicol; and 10 mg/kg for gentamicin. ⋯ However, at the doses used, the newer agents were not more effective in vivo than the older agents. This was shown by the similarities in clearance of bacteria from blood and cerebrospinal fluid, incidences of meningitis in bacteremic animals, and mortality rates. Thus, although these two newer antibiotics are more active in vitro and produce greater bactericidal titers in vivo, they do not appear to be superior to conventional regimens for treatment of neonatal E. coli bacteremia and meningitis.