Activity of moxalactam and cefotaxime alone and in combination with ampicillin or penicillin against group B streptococci.

AUTOR(ES)

Landesman, S H

RESUMO

The activities of moxalactam and cefotaxime, alone and combined with ampicillin or penicillin, against 40 isolates of group B streptococci were assessed by using the microtiter broth dilution, checkerboard, and time-kill techniques. Penicillin and cefotaxime were bactericidal for all isolates at concentrations of 0.06 micrograms/ml or less. Ampicillin was slightly less active. Moxalactam was bactericidal for all strains at concentrations of 4 to 8 micrograms/ml. The ampicillin- moxalactam combination was partially synergistic for 60% of the isolates tested; the ampicillin-cefotaxime combination was partially synergistic for 35% of these isolates. No instances of antagonism were observed. In time-kill evaluations, ampicillin (3.0 micrograms/ml) and penicillin (0.75 micrograms/ml) effected 2.5 to 3.5 log10 reductions in numbers of colony-forming units. The addition of 4 micrograms of cefotaxime per ml or 8 to 16 micrograms of moxalactam per ml to penicillin or ampicillin did not alter killing kinetics. Moxalactam and cefotaxime neither enhanced nor decreased the activity of ampicillin or penicillin against group B streptococci.

Documentos Relacionados

• In vitro bactericidal synergy of gentamicin combined with penicillin G, vancomycin, or cefotaxime against group G streptococci.
• Enhanced activity of the combination of penicillin G and gentamicin against penicillin-resistant viridans group streptococci.
• In vitro activity of moxalactam alone and in combination with penicillin against common meningeal pathogens.
• Comparative in vitro bactericidal activity of cefonicid, ceftizoxime, and penicillin against group B streptococci.
• Bactericidal and synergistic activity of moxalactam alone and in combination with gentamicin against Pseudomonas aeruginosa.