[In vitro activity of cefoxitin, a new cephalosporin (author's transl)].

The minimal inhibitory concentrations (MIC) of Cefoxitin (CEX), Cefazolin (CEZ) and Cephalothin (CEF) against E. coli (n = 380), Klebsiella pneumoniae (n =108) and Staph. aureus (n = 47) were determined by the agar diffusion method. For Proteus mirabilis (n = 69) and indole-positive Proteus species (n = 23), the tube dilution test was used. CEF was the most active against Staph. aureus while CEZ showed greater activity against E. coli. CEX was the most active against Kl. pneumoniae and Proteus species. In particular, CEX was also active against pathogens resistant to CEF or CEZ. The good bactericidal effect of CEX was demonstrated by membrane filtration methods.