[Bactericidal kinetics of cefazolin, cefoxitin and amikacin alone and in combination (author's transl)]

The in vitro activity of cefazolin, cefoxitin und amikacin alone and in combination was determined via membrane filtration against E. coli (n = 2), K. pneumoniae (n = 2) and of cefoxitin and amikacin against Proteus vulgaris (n = 1). Therapeutically achievable concentrations of cefazolin (10 micrograms/ml), cefoxitin (10 micrograms/ml) and amikacin (10 micrograms/ml) lead to a rapid bactericidal effect against all of our strains. The combination of cefazolin (10 micrograms/ml) and amikactin (5 micrograms/ml) and cefoxitin (10 micrograms/ml and amikacin (5 micrograms/ml) was synergistic against only one of the 2 K. pneumoniae strains. Cefoxitin and amikacin were antagonistic against the P. vulgaris strain but synergistic against both E. coli strains.