Bactericidal activity of cefoperazone in comparison with other beta-lactam antibiotics and gentamicin.

Killing curves were employed to determine the in vitro bactericidal activity of cefoperazone against several aerobic bacterial species of clinical origin. Cefoperazone was bactericidal at concentrations equal to, or greater than, the minimal inhibitory concentration (MIC) but allowed regrowth of the organisms after four to six hours when tested in concentrations of one-fourth or one-half the MIC. Comparative studies with gentamicin, LY127935 (moxalactam), piperacillin, cefamandole, and cephalothin indicate that, in general, cefoperazone demonstrated similar killing activity as other beta-lactam compounds, with some strain differences noted. Gentamicin, as the representative aminoglycoside, demonstrated a greater rate of bactericidal activity than the beta-lactam compounds studied.