[Comparative effect of apalcillin and other beta-lactam antibiotics against the Bacteroides fragilis group]. / Activité comparée de l'apalcilline à celle d'autres bêtalactamines vis-à-vis de Bacteroides du groupe fragilis.

The in vitro activity of apalcillin was compared with those of mezlocillin, piperacillin, cefoxitin, cefotaxime and cefotetan against 50 strains of Bacteroides fragilis group. The minimal concentrations were determined by a microdilution method in Wilkins-Chalgren medium and subculturing on agar. On the basis of MICs and MBCs range, the activity of apalcillin was similar to that of other beta-lactam antibiotics; cefoxitin was slightly more active. The mode MICs were as follow: apalcillin = 16 micrograms/ml, mezlocillin = 8 micrograms/ml, piperacillin = 2 micrograms/ml, cefoxitin = 8 micrograms/ml, cefotaxime = 8 and 32 micrograms/ml, cefotetan = 4 micrograms/ml. All the strains of B. thetaiotaomicron and B. vulgatus were susceptible to the six beta lactam compounds. The MBCs and MICs were similar. Apalcillin had the greatest bactericidal activity.