Journal of Antimicrobial Chemotherapy, Vol 40, 679-686, Copyright © 1997 by The British Society for Antimicrobial Chemotherapy
JD Knudsen, K Fuursted, N Frimodt-Moller and F Espersen
The purpose of this study was to compare the effect, both in vitro and in
vivo, of cefepime with those of four other cephalosporins, namely
ceftriaxone, cefotaxime, cefuroxime and cephalothin, against penicillin-
resistant pneumococci. One hundred pneumococcal strains, 31 penicillin-
susceptible, 30 penicillin-intermediate-resistant and 39 penicillin-
resistant pneumococci, were used in MIC studies. Time-kill experiments were
carried out for four strains. In the mouse peritonitis model, the dose that
gave protection to 50% of mice challenged with a lethal dose of pneumococci
(ED50) was determined for three pneumococci and five cephalosporins. The
MICs of all five cephalosporins and penicillin correlated significantly
with each other. In vitro, the most potent cephalosporins against
pneumococci were cefotaxime, ceftriaxone and cefepime, followed by
cefuroxime and cephalothin. In time-kill experiments, carried out for four
pneumococci, no differences were found in the killing effect of these five
cephalosporins in relation to MICs. In the mouse peritonitis model, there
was no significant correlation between log(MIC) and log(ED50) for the five
cephalosporins against three pneumococci (Spearman's rho = 0.39, P = 0.16).
However, if the values for cefepime against the three pneumococci were
excluded, there was a significant correlation for the remaining four
cephalosporins (Spearman's rho = 0.62, P = 0.04). For all three
pneumococci, the ED50s of cefepime were lower than expected from the MICs.
It was not possible to explain this beneficial difference in the effect of
cefepime in terms of in-vitro bactericidal activities, serum protein
binding or pharmacodynamic parameters.
ORIGINAL ARTICLES
Comparison of the effect of cefepime with four cephalosporins against pneumococci with various susceptibilities to penicillin, in vitro and in the mouse peritonitis model
Department of Research and Development, Statens Serum Institut, Copenhagen-S, Denmark.
![]()
CiteULike
Connotea
Del.icio.us What's this?