Journal of Antimicrobial Chemotherapy (1978) 4, 47-54 /3-Lactamases of subspecies of Bacteroides fragilis

The /Mactamase activities of 64 strains of Bacteroides fragilis were studied. The subspecies of Bacteroides fragilis were found to have /Mactamases which focussed at distinctive isoelectric points. Five strains which showed a high degree of resist-ance to /J-lactam antibiotics showed three separate types of resistance, two of which were enzymic. Cephalosporins showed variable degrees of susceptibility to hydrolysis by the Bacteroides fragilis enzymes but cefoxitin was unaffected