In vitro studies with cefazedone.

The minimum inhibitory concentrations of the new cephalosporin derivative (6R,7R)-7-(2-[3,5-dichloro-4-oxo-1(4H)-pyridyl]-acetamido)-3-([(5-methyl-1,3,4-thiadiazol-2-yl)-thio]methyl)-8-oxo-5-thia-1-azabicyclo[4,2,3]oct-2-ene-2-carboxylic acid (cefazedone, Refosporen) were tested in vitro against 358 bacterial strains. The antibacterial activity of cefazedone corresponds largely to that of cephalothin. Cefazedone is also active at a concentration of 16 micrograms/ml against 100% of enterococci, which can be classified as moderately effective, compared to cephalothin, which is completely ineffective. The MIC values from the dilution broth technique are in good correlation with the results determined by agar diffusion tests.